WO2024115513A1

WO2024115513A1 - Height adjustment mechanism, seat adjustment device, rotation adjustment mechanism and chair

Info

Publication number: WO2024115513A1
Application number: PCT/EP2023/083421
Authority: WO
Inventors: Huan NING; Zhiyang He; Tao Wang
Original assignee: Wonderland Switzerland Ag
Priority date: 2022-11-28
Filing date: 2023-11-28
Publication date: 2024-06-06
Also published as: CN118078068A

Abstract

A height adjustment mechanism, a seat adjustment device, a rotation adjustment mechanism and a chair are disclosed. The height adjustment mechanism is disposed between the bracket assembly including a base (5), and the seat assembly including a seat (1). The height adjustment mechanism includes a supporting base (27) integrated with the base or rotatably mounted on the base, and two adjustment members (21). The supporting base supports the seat through the two adjustment members. Lower ends of the two adjustment members are respectively pivotally connected to the supporting base through two first shafts (31), and upper ends of the two adjustment members are respectively movably connected to the seat to form two connecting points. The two adjustment members are rotatable respectively around corresponding first shafts to change positions of the two connecting points relative to the supporting base or the seat, so as to raise or lower the seat.

Description

Wonderland Switzerland AG

HEIGHT ADJUSTMENT MECHANISM, SEAT ADJUSTMENT DEVICE, ROTATION ADJUSTMENT MECHANISM AND CHAIR

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to Chinese patent application No. 2022115043324, filed on November 28, 2022, Chinese patent application No. 2023105486462, filed on May 15, 2023, Chinese patent application No. 2023105751862, filed on May 19, 2023, and Chinese patent application No. 2023107825983, filed on June 28, 2023, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

[0002] The present disclosure relates to a height adjustment mechanism, a seat adjustment device, a rotation adjustment mechanism, and a chair.

BACKGROUND

[0003] A high chair includes a bracket with a plurality of legs and a seat supported by the bracket, and is used to support a child in a high sitting position, which facilitates the caregiver to feed the child, or facilitates the child to eat with the caregiver. The high chair provides children with a fixed sitting position, but table heights in different families are not the same, or there are multiple table heights in the same family, thus a high chair with a fixed height cannot adapt to different table heights.

[0004] For some high chairs, the seat is slidably mounted on the legs, and the height adjustment is performed by sliding the seat relative to the legs.

SUMMARY

[0005] A first aspect of present disclosure provides a height adjustment mechanism disposed between a bracket assembly including a base, and a seat assembly including a seat. The height adjustment mechanism includes: a supporting base integrated with the base or rotatably mounted on the base; and two adjustment members. The supporting base supports the seat through the two adjustment members. Lower ends of the two adjustment members are respectively pivotally connected to the supporting base through two first shafts, and upper ends of the two adjustment members are respectively movably connected to the seat to form two connecting points. The two adjustment members are rotatable respectively around corresponding first shafts to change positions of the two connecting points relative to the supporting base or the seat, so as to raise or lower the seat. [0006] In the first aspect, the two adjustment members are rotatable in opposite directions respectively around the corresponding first shafts to change the positions of the two connecting points relative to the supporting base or the seat.

[0007] In the first aspect, the seat has a first height and a second height relative to the supporting base, and the first height is greater than the second height. When the seat is at the first height, connecting points between the supporting base, the seat, and the two adjustment members define a first area. When the seat is at the second height, the connecting points between the supporting base, the seat, and the two adjustment members define a second area. The first area is greater than the second area.

[0008] In the first aspect, the two adjustment members are arranged opposite and separated from each other in a first horizontal direction, and an axial direction of each first shaft is perpendicular to the first horizontal direction. When the two adjustment members rotate in opposite directions around the corresponding first shafts, the two connecting points are closer to or farther away from each other in the first horizontal direction while moving in a vertical direction.

[0009] In the first aspect, the height adjustment mechanism further includes two first locking members in one-to-one correspondence with the two adjustment members, and each of the two first locking members has a locking position where the first locking member locks a position of a corresponding adjustment member relative to the seat.

[0010] In the first aspect, the seat is provided with a plurality of slots, and each of the two first locking members is selectively engaged with a corresponding one of the plurality of slots.

[0011] In the first aspect, the height adjustment mechanism further includes a first elastic element configured to drive each of the two first locking members to be engaged with the seat.

[0012] In the first aspect, the height adjustment mechanism further includes two slide blocks slidably cooperated with the seat. The two slide blocks are respectively pivotally connected to the upper ends of the two adjustment members through second shafts parallel to the first shaft, and the two slide blocks are in one-to-one correspondence with the two first locking members, and each of the two first locking members is movably connected to the corresponding slide block.

[0013] In the first aspect, a receiving cavity is provided at a bottom of the seat, the two slide blocks are located in the receiving cavity, and each of the second shafts extends from the side wall of the receiving cavity and is pivotally connected to the upper end of the corresponding adjustment member. The side wall of the receiving cavity is provided with first elongated holes corresponding to both ends of each second shaft.

[0014] In the first aspect, each of the two first locking members moves in a vertical direction relative to the corresponding slide block to move to a locking position where the first locking member is engaged with the seat or an unlocking position where the first locking member is disengaged from the seat.

[0015] In the first aspect, the height adjustment mechanism further includes two first driving members in one-to-one correspondence with the two first locking members, each of the first driving members is drivingly connected to the corresponding first locking member, and each of the first driving members drives the corresponding first locking member to move and disengage from the seat when subjected to an external force.

[0016] In the first aspect, one of the first locking member and the corresponding first driving member is provided with a first pin, and another of the first locking member and the corresponding first driving member is provided with a driving slope, the first pin is parallel to the first shaft, and the driving slope abuts against the first pin. When each of the first driving members is subjected to an external force, the driving slope and the first pin abuts against each other to drive the first locking member to move.

[0017] In the first aspect, the height adjustment mechanism includes at least one first unlocking member operatively connected to the two first driving members for applying the external force to each of the first driving members.

[0018] In the first aspect, the height adjustment mechanism includes two first unlocking members in one-to-one correspondence with the two first driving members, and each of the first unlocking members is connected to the corresponding first driving member through a first traction member disposed in a protective jacket.

[0019] In the first aspect, the height adjustment mechanism further includes a second elastic element configured to drive the at least one first unlocking member to return to its original position. [0020] In the first aspect, the two adjustment members are arranged oppositely and separated from each other in a first horizontal direction. Each of the adjustment members includes a pair of connecting arms arranged oppositely in a second horizontal direction perpendicular to the first horizontal direction, upper ends of the pair of connecting arms are movably connected to the seat, lower ends of the pair of connecting arms are pivotally connected to the supporting base through the first shafts, and the pair of connecting arms are connected to each other through a side plate. At least one of the two opposite surfaces of the pair of connecting arms is provided with a sliding slot, and the seat is provided with a boss slidably cooperated with the sliding slot.

[0021] In the first aspect, the two adjustment members are arranged oppositely and separated from each other in a first horizontal direction, and an axial direction of the first shaft is perpendicular to the first horizontal direction. The supporting base is provided with two supporting members arranged oppositely in the first horizontal direction, and the two supporting members are in one-to- one correspondence with the two adjustment members. One of an upper end of the supporting member and the lower end of the adjustment member is provided with a mounting hole, and another of the upper end of the supporting member and the lower end of the adjustment member is provided with the first shaft, the first shaft being pivotally connected to the mounting hole. An angle limiting mechanism is disposed between at least one pair of supporting member and corresponding adjustment member, and the angle limiting mechanism is configured to limit a range of rotation angle of the adjustment member.

[0022] In the first aspect, a distance between the upper ends of the two supporting members is greater than a distance between lower ends of the two supporting members.

[0023] In the first aspect, the angle limiting mechanism includes: a first arc-shaped groove located on a hole wall of the mounting hole and extending in a circumferential direction; and an elastic telescopic pin mounted on the first shaft and adapted to be inserted into the first arc-shaped groove. [0024] In the first aspect, the hole wall of the mounting hole is provided with an inclined surface configured to guide the elastic telescopic pin to be inserted into the first arc-shaped groove.

[0025] A second aspect of the present application provides a seat adjustment device disposed between a bracket assembly and a seat assembly. The seat adjustment device includes: a first adjustment column connected to a seat of the seat assembly; a second adjustment column connected to a base of the bracket assembly, and insertably cooperated with the first adjustment column; and a height adjustment mechanism disposed between the first adjustment column and the second adjustment column, and switchable between a locking state and an unlocking state. When the height adjustment mechanism is in the locking state, the first adjustment column is fixed at a certain height position relative to the second adjustment column, and when the height adjustment mechanism is in the unlocking state, the first adjustment column is movable relative to the second adjusting column. [0026] In the second aspect, the height adjustment mechanism includes: a plurality of adjustment holes disposed at one of the first adjustment column and the second adjustment column; and a height locking member movably disposed on another of the first adjustment column and the second adjustment column, and switchable between a first locking position and a first unlocking position. When the height locking member is at the first locking position, the height locking member is engaged with at least one of the plurality of adjustment holes, and when the height locking member is at the first unlocking position, the height locking member is disengaged from the at least one of the adjustment holes.

[0027] In the second aspect, the height adjustment mechanism further includes a height driving member, one of the height locking member and the height driving member is provided with a first driving groove, another of the height locking member and the height driving member is provided with a first driving pin, an extension direction of the first driving groove is inclined relative to a moving direction of the height locking member, the first driving pin is insertably cooperated with the first driving groove and is movable along the first driving groove, and the height driving member is configured to drive the height locking member to move between the first locking position and the first unlocking position. [0028] In the second aspect, the plurality of adjustment holes is disposed on the second adjustment column, and the height locking member is disposed on the first adjustment column. The height adjustment mechanism further includes a fixed base connected to the first adjustment column, the fixed base is provided with a guide groove, an extension direction of the guide groove is perpendicular to an axial direction of the first adjustment column, and the first driving pin is insertably cooperated with the guide groove and is movable along the guide groove.

[0029] In the second aspect, the height adjustment mechanism further includes a first reset member adapted to bias the height driving member to move toward the first locking position.

[0030] In the second aspect, the height adjustment mechanism further includes: a height operating member switchable between a first position and a second position; and a traction member having an end connected to the height driving member, and another end connected to the height operating member. The height operating member is operable to drive the height driving member to move through the traction member, so as to drive the height locking member from the first locking position moves to the first unlocking position.

[0031] In the second aspect, the height adjustment mechanism further includes a second reset member adapted to bias the height operating member to move toward the first position.

[0032] In the second aspect, the seat adjustment device further includes a mounting base, through which the first adjustment column is connected to the seat. The mounting base includes: an upper cover connected to a bottom of the seat and the first adjustment column; and a lower cover enclosed with the upper cover to form a first receiving cavity, at least a part of the height operating component being received in the first receiving cavity.

[0033] In the second aspect, the mounting base further includes a connecting tube arranged around an outer periphery of the first adjustment column and enclosed with the adjustment column to form a second receiving cavity, the second receiving cavity is connected to the first receiving cavity, and at least a part of the traction member is received in the second receiving cavity.

[0034] In the second aspect, the height adjustment mechanism further includes a fixed base arranged on an end of the first adjustment column away from the seat, at least a part of the fixed base is received in the second receiving cavity, and the height driving member and the height locking member are received in the second receiving cavity, and are respectively movably connected to the fixed base.

[0035] In the second aspect, the seat adjustment device further includes an anti-separation mechanism. The anti-separation mechanism includes: an elastic finger disposed on the connecting tube, and having a hook portion protruding in a direction away from the second receiving cavity; and an engaging groove disposed on the bracket assembly, an extension direction of the engaging groove being parallel to the axial direction of the second adjustment column. The hook portion is movable along the engaging groove, and an end of the engaging groove limits a movement stroke of the hook portion.

[0036] In the second aspect, the bracket assembly further includes an adjustment base connected to the base, the adjustment base is disposed at least partially around the second adjustment column and is connected to the second adjustment column, and the engaging groove is disposed on the adjustment base.

[0037] In the second aspect, the bracket assembly further includes an adjustment base relatively rotatably connected to the base, a first accommodation groove is defined between the adjustment base and the second adjustment column, the connecting tube is slidably cooperated with the first accommodation groove, and the connecting tube is non-rotatable relative to the adjustment base.

[0038] In the second aspect, the first adjustment column is provided with a hollow inner cavity, and the second adjustment column is inserted into the hollow inner cavity and is movable along the hollow inner cavity.

[0039] In the second aspect, an outer surface of the second adjustment column is provided with a protrusion, and the protrusion abuts against and is slidably cooperated with a cavity wall of the hollow inner cavity of the first adjustment column.

[0040] In the second aspect, an end of the first adjustment column away from the seat assembly is provided with a fixed base, and the fixed base is provided with a groove adapted to cooperate with the protrusion and allowing the protrusion to pass therethrough.

[0041] A third aspect of the present disclosure provides a rotation adjustment mechanism disposed between a seat assembly and a bracket assembly that are rotatable relative to each other, so as to operatively lock a circumferential position of the seat assembly relative to the bracket assembly. [0042] In the third aspect, the seat assembly is mounted on a supporting base, the bracket assembly includes a base, and the supporting base is rotatably mounted on the base. The rotation adjustment mechanism includes a third locking member mounted on one of the supporting base and the base, another of the supporting base and the base is provided with a plurality of positioning holes in the circumferential direction, and the third locking member is selectively inserted into one of the plurality of positioning holes to lock a position of the supporting base relative to the seat.

[0043] In the third aspect, the seat assembly is connected to the bracket assembly through an adjustment base. The rotation adjustment mechanism is operably disposed on the bracket assembly, the rotation adjustment mechanism includes a unlocking state and a locking state, when the rotation adjustment mechanism is in the unlocking state, the adjustment base is rotatable relative to the bracket assembly or the seat assembly to adjust circumferential relative positions of the seat assembly and the bracket assembly; and when the rotation adjustment mechanism is in the locking state, the adjustment seat is non-rotatable relative to the bracket assembly and the seat assembly, so as to lock the circumferential relative positions of the seat assembly and the bracket assembly.

[0044] In the third aspect, the seat assembly is connected to the first adjustment column, the adjustment base is connected to the second adjustment column, and the second adjustment column is insertably cooperated with the first adjustment column. A height adjustment mechanism is disposed between the first adjustment column and the second adjustment column, and the height adjustment mechanism is switchable between the locking state and the unlocking state, when the height adjustment mechanism is in the locking state, the first adjustment column is fixed at a certain height position relative to the second adjustment column, and when the height adjustment mechanism is in the unlocking state, the first adjustment column is movable relative to the second adjustment column.

[0045] In the third aspect, the rotation adjustment mechanism includes: a plurality of insertable slots disposed in one of the bracket assembly and the adjustment base; and a rotation locking member disposed on another of the bracket assembly and the adjustment base, the rotation locking member being switchable between a second locking position and a second unlocking position. When the rotation locking member is in the second locking position, the rotation locking member is engaged with at least one of the plurality of insertable slots, so that the adjustment base is non-rotatable relative to the bracket assembly. When the rotation locking member is in the second unlocking position, the rotation locking member is disengaged from the plurality of insertable slots, so that the adjustment base is rotatable relative to the bracket assembly.

[0046] In the third aspect, the rotation locking member is disposed on the adjustment base, and the adjustment base is provided with a second through hole, through which the locking member is movably inserted.

[0047] In the third aspect, the rotation adjustment mechanism further includes a rotation operating member mounted to the adjustment base. The rotation operating member is drivingly connected to the rotation locking member, so as to drive the rotation locking member to switch between the second locking position and the second unlocking position.

[0048] In the third aspect, the rotation locking member is provided with a first driving surface, the rotation operating member is provided with a second driving surface abutting against the first driving surface, and the rotation operating member is operable to push the first driving surface via the second driving surface, thereby driving the rotation locking member to switch to the second unlocking position.

[0049] In the third aspect, the rotation locking member is provided with an insertion slot, a side wall of the insertion slot forms a first driving surface, the rotation operating member includes an insertion portion, and a side wall of the insertion portion forms a second driving surface inclined relative to an extension direction of the rotation locking member, the insertion portion is insertably cooperated with the insertion slot, and the second driving surface abuts against the first driving surface.

[0050] In the third aspect, the bracket assembly is provided with an accommodation hole, the adjustment base is at least partially received in the accommodation hole, the rotation operating member is movably connected to the adjustment base, and the rotation operating member is at least partially exposed from the accommodation hole for operation.

[0051] In the third aspect, the rotation adjustment mechanism further includes a rotation reset member adapted to bias the rotation locking member to move toward the second locking position.

[0052] In the third aspect, the rotation locking members are arranged in pairs, and the rotation reset member is connected or abuts between two rotation locking members in a pair to simultaneously bias the two rotation locking members.

[0053] In the third aspect, the bracket assembly includes a leg base connected to the plurality of legs, the seat assembly is mounted on the seat plate, and the seat plate is rotatably connected to the leg base. The rotation adjustment mechanism is disposed between the leg base and the seat plate, when the rotation adjustment mechanism is in the unlocking state, the seat plate is rotatable relative to the leg base, and when the rotation adjustment mechanism is in the locking state, the seat plate is non-rotatable relative to the leg base.

[0054] In the third aspect, the rotation adjustment mechanism further includes a positioning member having a third locking position and a third unlocking position. The leg base is provided with a first positioning groove, and the seat plate is provided with a second positioning groove. When the rotation adjustment mechanism is in the locking state, the positioning member is in the third locking position, and the positioning member is engaged with both the first positioning groove and the second positioning groove. When the mechanism is in the unlocking state, the positioning member is in the third unlocking position, and the positioning member is disengaged from at least one of the first positioning groove and the second positioning groove.

[0055] In the third aspect, the positioning member includes a positioning portion adapted to be engaged with the second positioning groove and the first positioning groove, and a cross-section of the positioning portion has a non-circular rotationally symmetrical shape.

[0056] In the third aspect, the rotation adjustment mechanism further includes a positioning reset member adapted to bias the positioning member to move toward the third locking position, the positioning reset member abuts or is connected between the positioning member and the leg base.

[0057] In the third aspect, the rotation adjustment mechanism further includes a positioning operating member drivingly connected to the positioning member. The positioning operating member is operably disposed on the leg base, and the positioning operating member is operable to drive the positioning member to move toward the third unlocking position.

[0058] In the third aspect, the positioning operating member is disposed on a side of the leg base away from the first positioning groove, and the positioning operating member is connected to the positioning member through a fastener.

[0059] In the third aspect, the seat plate is provided with a first receiving groove, the leg base is provided with a rotation connecting portion, and at least a part of the rotation connecting portion is received in the first receiving groove and abuts against a side wall of the first receiving groove, so that the seat plate is rotatable about a rotation axis relative to the leg base.

[0060] In the third aspect, the seat plate includes a first seat plate and a second seat plate, the first seat plate is provided with a first receiving groove, the second seat plate is arranged at a groove opening of the first receiving groove, an opening is formed between the second seat plate and the first seat plate, and at least a part of the rotation connecting portion extends into the opening and is engaged with a groove wall of the first receiving groove.

[0061] In the third aspect, the seat plate includes a first seat plate and a second seat plate, which enclose to form a first receiving groove, a connecting rod is inserted into the first receiving groove, and a part of the connecting rod extending out from the first receiving groove is connected to a backrest.

[0062] In the third aspect, the bracket assembly further includes a roller rotatably disposed on the leg base, the roller is provided with a first slope, and the seat plate is provided with a second slope surrounding a rotation axis of the seat plate and is in rolling contact with the first slope.

[0063] In the third aspect, the positioning operating member is rotatably disposed on the leg base, the leg base is provided with a positioning rib, and the positioning operating member is provided with a retaining rib abutting against the positioning rib to maintain the positioning member in the third unlocking position.

[0064] A fourth aspect of the present disclosure provides a chair. The chair includes: the height adjustment mechanism according to the first aspect; and/or the seat adjustment device according to the second aspect; and/or the rotation adjustment mechanism according to the third aspect.

[0065] A fifth aspect of the present disclosure provides a chair. The chair includes a bracket assembly. The bracket assembly includes a plurality of legs and a folding mechanism configured to unfold or fold the plurality of legs.

[0066] In the fifth aspect, the folding mechanism includes: an adjustment base; a plurality of connecting members mounted on the adjustment base; and at least one second locking member. The adjustment base is slidably connected to the plurality of legs through the plurality of connecting members, the at least one second locking member is configured to be engaged with at least one of the plurality of legs, so as to lock relative positions of the adjustment base and the at least one of the plurality of legs.

[0067] In the fifth aspect, two or more lock slots are disposed on the at least one of the plurality of legs, and the two or more lock slots are spaced apart along a length direction of the at least one of the plurality of legs, so as to be selectively engaged with the at least one second locking member.

[0068] In the fifth aspect, the chair further includes a second unlocking member mounted on the adjustment base and operably connected to at least one second locking member. [0069] In the fifth aspect, each of the plurality of connecting members has a notch, each of the plurality of legs is provided with a sliding rail, and each of the plurality of connecting members, via its notch, is slidably connected to the sliding rail on the corresponding leg.

[0070] In the fifth aspect, the bracket assembly includes a base with a slideway extending in a vertical direction, and the plurality of legs are respectively pivotally connected to the base. The folding mechanism includes: a first sliding member slidably cooperated with the slideway; and a plurality of linking members connected between the first sliding member and the plurality of legs. When the first sliding member moves along the slideway, the plurality of linking members drive the plurality of legs to unfold or fold synchronously.

[0071] In the fifth aspect, the folding mechanism further includes: a stabilizing member connected to the first sliding member through at least one connecting member, thereby allowing the stabilizing member to move in a vertical direction along with the first sliding member, the stabilizing member having a rotation axis parallel to the vertical direction; and at least one first motion conversion mechanism disposed between the stabilizing member and the base. When the stabilizing member moves in the vertical direction, each of the first motion conversion mechanisms drives the stabilizing member to rotate about the rotation axis relative to the first sliding member.

[0072] In the fifth aspect, one of the stabilizing member and the first sliding member is provided with at least one arc-shaped hole, another of the stabilizing member and the first sliding member is provided with at least one through hole, and the at least one connecting member is inserted into the at least one arc-shaped hole and the at least one through hole along the vertical direction.

[0073] In the fifth aspect, the at least one connecting member includes at least two engaging hooks extending from the stabilizing member or the first sliding member, and each of the engaging hooks extends in the vertical direction.

[0074] In the fifth aspect, each of the first motion conversion mechanisms includes: a first driving chute disposed on one of the base and the stabilizing member; and a first driving pin disposed on another of the base and the stabilizing member and slidably cooperated with the first driving chute.

[0075] In the fifth aspect, the slideway is formed by a column portion extending in the vertical direction, and the first sliding member is sleeved on an outside of the column portion.

[0076] In the fifth aspect, the slideway is formed by the column portion extending in the vertical direction, the first sliding member and the stabilizing member are sleeved on the outside of the column portion, and the at least one first motion conversion mechanism is disposed between the stabilizing member and the column portion.

[0077] In the fifth aspect, the folding mechanism further includes at least one locking member mounted to the base and configured to lock the first sliding member, so as to limit a movement of the first sliding member relative to the slideway.

[0078] In the fifth aspect, the folding mechanism further includes: at least one unlocking member operatively connected to the at least one locking member for driving the at least one locking member to unlock the first sliding member; and/ or at least one elastic member configured to drive the at least one locking member to lock the first sliding member.

[0079] In the fifth aspect, the first sliding member includes at least one locking portion, and each of the at least one locking portion includes a locking recess. Each of the at least one locking member includes a plurality of locking protrusions, which extend in a transverse direction and are spaced apart in a vertical direction. The locking recesses are selectively cooperated with the plurality of locking protrusions to lock the first sliding member at different positions on the slideway.

[0080] In the fifth aspect, the first sliding member includes at least one locking portion, each of the locking portions includes a plurality of locking recesses, and the plurality of locking recesses are spaced apart in a vertical direction. Each of the at least one locking member includes a locking protrusion extending in a transverse direction. The plurality of locking recesses is selectively cooperated with the locking protrusions to lock the first sliding member at different positions on the slideway.

[0081] In the fifth aspect, each of the at least one unlocking member is mounted on the base and is movable in a vertical direction. A second movement conversion mechanism is disposed between each of the at least one unlocking member and each of the at least one locking member, and is configured to convert a movement of each of the at least one unlocking member in the vertical direction to a movement of each of the at least one locking member in a transverse direction, so as to allow each of the at least one locking member to lock or unlock the first sliding member.

[0082] In the fifth aspect, the second movement conversion mechanism includes: a second driving chute disposed on one of the corresponding unlocking member and the corresponding locking member; and a second driving pin disposed on another of the corresponding unlocking member and the corresponding locking member, and slidably cooperated with the second driving chute.

[0083] In the fifth aspect, the base includes a receiving cavity, the slideway, the first sliding member and the stabilizing member are located in the receiving cavity, and the base is provided with a plurality of first through grooves communicating with the receiving cavity, and first ends of the plurality of linking members are pivotally connected to the first sliding member after extending through the plurality of first through grooves.

[0084] In the fifth aspect, covers are respectively mounted on the plurality of legs, each of the covers is provided with a second through groove, and a second end of each of the plurality of linking members is pivotally connected to one of the plurality of legs after extending through the second through groove.

[0085] In the fifth aspect, the bracket assembly is mounted on the seat plate, and the plurality of legs is configured to be pivotable relative to the seat plate, so that the chair is switchable between a raised state and a lowered state. The bracket assembly further includes a footrest movably connected to the plurality of legs, the footrest is movable between a first position and a second position to drive the plurality of legs to pivot. When the footrest is at the first position, the plurality of legs is unfolded, so that the chair is in the lowered state, and when the footrest is at the second position, the plurality of legs is folded, so that the chair is in the raised state.

[0086] In the fifth aspect, each of the plurality of legs is provided with a second sliding member pivotally connected to the footrest, so that the footrest is slidable together with the second sliding member between the first position and the second position.

[0087] In the fifth aspect, the folding mechanism includes: an engaging member movably disposed on at least one of the plurality of legs, the engaging member being switchable between a fourth locking position and a fourth unlocking position; and an engaging hole disposed on the second sliding member. When the folding mechanism is in the locking state, the engaging member is in the fourth locking position, and is engaged with the engaging hole, so as to lock the second sliding member relative to the legs, and when the folding mechanism is in the unlocking state, the engaging member is in the fourth unlocking position, and is disengaged from the engaging hole.

[0088] In the fifth aspect, the folding mechanism further includes a driving member, one of the driving member and the engaging member is provided with a driving groove, another of the driving member and the engaging member is provided with a driving pin, an extension direction of the driving groove is inclined relative to a moving direction of the engaging member, and the driving pin is insertably cooperated with the driving groove and movable along the driving groove to drive the engaging member to move between the fourth locking position and the fourth unlocking position.

[0089] In the fifth aspect, the folding mechanism further includes: a fixed base fixedly disposed on at least one of the plurality of legs, the fixed base being provided with a guide groove extending parallel to the moving direction of the driving member, and the driving pin being insertably cooperated with the guide groove and being movable along the guide groove; and/ or a folding reset member adapted to bias the driving member so that the driving member drives the engaging member to move toward the fourth locking position.

[0090] In the fifth aspect, the folding mechanism further includes: a folding operating member movably disposed on the bracket assembly; and a traction member having an end connected to the driving member, and another end connected to the folding operating member. The folding operating member is operable to drive the driving member to move through the traction member, so that the engaging member is driven to move from the fourth locking position to the fourth unlocking position. [0091] In the fifth aspect, the plurality of legs is provided with a hollow inner cavity, and at least a part of the folding mechanism is received in the hollow inner cavity.

[0092] In the fifth aspect, at least one of the plurality of legs is provided with a first limiting member adapted to abut against the second sliding member to limit the footrest from sliding upward from the first position. [0093] In the fifth aspect, at least one of the plurality of legs is provided with a second limiting member adapted to abut against the second sliding member to limit the footrest from moving downward from the second position.

[0094] In the fifth aspect, each of the plurality of legs includes a first leg and a second leg, one end of the first leg is connected to the seat plate, and another end of the first leg is detachably connected to the second leg.

[0095] In the fifth aspect, the chair further includes a seat detachment mechanism. The seat assembly is detachably connected to the mounting base through the seat detachment mechanism. The seat detachment mechanism includes: an engaging hole disposed on the mounting base; and a detachment locking member disposed on the seat assembly, the detachment locking member having a hook and being movable between a third position and a fourth position. When the detachment locking member is in the third position, the hook is engaged with the engaging hole, so that the seat assembly is fixed relative to the mounting base, and when the detachment locking member is in the fourth position, the hook is disengaged from the engaging hole, so that the seat assembly is detachable from the mounting base.

[0096] In the fifth aspect, the mounting base is provided with a connecting groove, and the engaging hole is disposed on a side wall of the connecting groove and is connected to the connecting groove, the detachment locking member is insertably cooperated with the connecting groove, and the detachment locking member is movable in a direction parallel to a bottom wall of the connecting groove, and is movable between the third position and the fourth position.

[0097] In the fifth aspect, the seat detachment mechanism further includes: an engaging recess disposed on the mounting base; a detachment unlocking member operably disposed on the seat assembly, the detachment unlocking member having an engaging protrusion, and the detachment unlocking member being switchable between a sixth unlocking position and a sixth locking position; and a detachment reset member adapted to bias the detachment unlocking member, so that the detachment unlocking member moves toward the sixth locking position. When the detachment unlocking member is in the sixth locking position, the engaging protrusion is engageable with the engaging recess to limit the detachment locking member in the third position, and when the detachment locking member is in the sixth unlocking position, the engaging protrusion is disengaged from the engaging recess, so that the detachment unlocking member is switchable between the third position and the fourth position.

[0098] In the fifth aspect, the seat assembly is provided with a receiving hole, the engaging protrusion of the detachment unlocking member is adapted to extend through the receiving hole and to be engaged with the engaging recess, and an end of the detachment unlocking member away from the engaging protrusion is provided with an operating recess at least partially extending out of the receiving hole. [0100] In the fifth aspect, the seat assembly is provided with a second receiving groove, the detachment unlocking member is further provided with an abutting portion, at least a part of the abutting portion is received in the second receiving groove, the detachment reset member is received in the second receiving groove, and two ends of the detachment reset member respectively abut against a groove wall of the second receiving groove and the abutting portion.

[0101] In the fifth aspect, the bracket assembly is mounted on the seat plate, and the seat plate is equipped with a backrest. The seat assembly includes a seat and a backrest portion, the backrest portion is provided with a first connecting member, and the seat assembly is detachably connected to the backrest portion through the first connecting member. When the seat assembly is connected to the backrest, the chair is in a first use state, and when the seat assembly is separated from the backrest, the chair is in a second use state.

[0102] In the fifth aspect, the backrest is provided with a connecting hole, and the first connecting member is rotatably disposed on the seat assembly and is switchable between a fifth locking position and a fifth unlocking position. When the first connecting member is in the fifth unlocking position, the first connecting member is movable along an extension direction of the connecting hole, and the first connecting member is rotatable to the fifth unlocking position, and when the first connecting member is in the fifth locking position, the seat assembly and the first connecting member are capable of being located on two sides of the backrest respectively, and the first connecting member abuts against the backrest, so that the seat assembly and the backrest are relatively fixed.

[0103] In the fifth aspect, the backrest portion is provided with a connecting protrusion capable of being insertably cooperated with the connecting hole, and the first connecting member is rotatably connected to the connecting protrusion.

[0104] In the fifth aspect, a bottom of the seat assembly is provided with a second connecting member extending downward and forming a connecting groove thereon, and the second connecting member is configured to be engaged with the seat plate through the connecting groove.

[0105] In the fifth aspect, a backside of backrest is provided with a positioning protrusion, the first connecting member is correspondingly provided with a positioning recess, and when the first connecting member is in the fifth locking position, the positioning protrusion is engaged with the positioning recess.

[0106] In the fifth aspect, a side of the backrest away from the seat assembly is provided with a recess, and when the first connecting member is in the fifth locking position, the first connecting member abuts against a bottom wall of the recess.

[0107] In the fifth aspect, the seat assembly includes a seat and a tray, the tray is connected to the seat through the tray adjustment mechanism, and the tray adjustment mechanism includes: a plurality of positioning slots disposed on a side of the seat; and a tray unlocking member having an engaging portion, the tray unlocking member being movably disposed on the tray and having a seventh locking position and a seventh unlocking position. When the tray unlocking member is in the seventh locking position, the engaging portion is engaged with at least one of the plurality of positioning slots to fix the tray on the seat, and when the tray unlocking member is in the seventh unlocking position, the engaging portion is disengaged from the plurality of positioning slots, so that the tray is detachable from the seat or is movable relative to the seat.

[0108] In the fifth aspect, the tray has a front face capable of bearing loads and a back face away from the front face, the tray unlocking member is disposed on the back face, the tray unlocking member further has a second operating portion, and the second operating potion protrudes from the engaging portion and extends away from the back surface.

[0109] In the fifth aspect, the tray adjustment mechanism further includes an adjustment reset member disposed between the tray unlocking member and the tray, and the adjustment reset member is adapted to bias the tray unlocking member, so that the tray moves toward the seventh locking position.

[0110] In the fifth aspect, one of the tray and the tray unlocking member is provided with an elongated groove, and another of the tray and the tray unlocking member is provided with a connecting pin insertably cooperated with the elongated groove.

[OHl] In the fifth aspect, the tray is provided with a connecting plate arranged along a front and rear direction of the chair, the connecting plate is provided with a hole, and by passing through the hole, the engaging portion is capable of being engaged with or disengaged from the plurality of positioning slots.

[0112] In the fifth aspect, the tray is further provided with a limiting portion capable of abutting against the side of the seat to limit a movement stroke of the tray.

BRIEF DESCRIPTION OF THE DRAWINGS

[0113] The drawings forming part of the embodiments of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application.

[0114] FIG. 1 schematically shows a perspective view of a high chair according to an embodiment of the present application, and the high chair is provided with a height adjustment mechanism and a folding mechanism according to an embodiment of the present application.

[0115] FIG. 2 schematically shows a partial front view of the high chair shown in FIG. 1, with the height adjustment mechanism supporting the seat at a height.

[0116] FIG. 3 schematically shows a partial front view of the high chair shown in FIG. 1, with the height adjustment mechanism supporting the seat at another height. [0117] FIG. 4 schematically shows a rear perspective view of the high chair shown in FIG. 1.

[0118] FIG. 5 schematically shows a cross-sectional view of the high chair shown in FIG. 2 taken along Ui-Ui.

[0119] FIG. 6 schematically shows a cross-sectional view of the high chair shown in FIG. 5 taken along U2-U2.

[0120] FIG. 7 schematically shows a perspective view of an adjustment member of the high chair shown in FIG. 1.

[0121] FIG. 8 schematically shows a perspective view of a supporting base of the high chair shown in FIG. 1.

[0122] FIG. 9 schematically shows a bottom perspective view of a seat of the high chair shown in FIG. 1.

[0123] FIG. 10 schematically shows a perspective view of a first locking member and a first driving member of the high chair shown in FIG. 1.

[0124] FIG. 11 schematically shows a perspective view of some components of a height adjustment mechanism of the high chair shown in FIG. 1.

[0125] FIG. 12 schematically shows a bottom perspective view of the high chair shown in FIG. 1.

[0126] FIG. 13 schematically shows a partially exploded view of the high chair shown in FIG. 1 based on a perspective.

[0127] FIG. 14 schematically shows a partially exploded view of the high chair shown in FIG. 1 based on another perspective.

[0128] FIG. 15 schematically shows a perspective view of the high chair shown in FIG. 1, with the folding mechanism supporting the base at a height.

[0129] FIG. 16 schematically shows a perspective view of the high chair shown in FIG. 1, with the folding mechanism supporting the base at another height.

[0130] FIG. 17 schematically shows a bottom perspective view of the high chair shown in FIG. 16. [0131] FIG. 18 schematically shows a cross-sectional view of a bracket assembly of the high chair shown in FIG. 16 taken along U3-U3, with the bracket assembly being in an unfolded state.

[0132] FIG. 19 schematically shows a cross-sectional view of the bracket assembly shown in FIG. 18, with the bracket assembly being in a folded state.

[0133] FIG. 20 schematically shows a top perspective view of some components of the bracket assembly of the high chair shown in FIG. 1, with a second locking member being engaged with a corresponding lock slot.

[0134] FIG. 21 schematically shows a top perspective view of some components of the bracket assembly of the high chair shown in FIG. 1, with the second locking member being disengaged from the corresponding lock slot.

[0135] FIG. 22 schematically shows a perspective view of the high chair shown in FIG. 1, with lower legs of each of the legs being removed.

[0136] FIG. 23 schematically shows a perspective view of a carrier according to an embodiment of the present application, with the carrier having a leg folding structure according to an embodiment of the application, and with the leg folding structure being in an unfolded state.

[0137] FIG. 24 schematically shows a cross-sectional view of the leg folding structure shown in FIG. 23 taken along U4-U4.

[0138] FIG. 25 schematically shows another perspective view of the carrier shown in FIG. 23, with the leg folding structure being in a folded state.

[0139] FIG. 26 schematically shows a cross-sectional view of the leg folding structure shown in FIG. 25 taken along U5-U5.

[0140] FIG. 27 schematically shows an exploded view of the leg folding structure shown in FIG.

23-

[0141] FIG. 28 schematically shows a top view of the leg folding structure shown in FIG. 23, with the base being omitted.

[0142] FIG. 29 schematically shows a side view of the leg folding structure shown in FIG. 23.

[0143] FIG. 30 schematically shows a cross-sectional view of FIG. 29 taken along U6-U6, with a stabilizing member being omitted.

[0144] FIG. 31 schematically shows a perspective view, showing that a locking member, an unlocking member and an elastic member shown in FIG. 27 assembled together.

[0145] FIG. 32 schematically shows another perspective view, showing that the locking member, the unlocking member and the elastic member shown in FIG. 27 assembled together.

[0146] FIG. 33 is a schematic structural view of a child seat according to some embodiments of the present application.

[0147] FIG. 34 is a schematic structural view of the child seat shown in FIG. 33 after being adjusted.

[0148] FIG. 35 is a left side view of the child seat shown in FIG. 34.

[0149] FIG. 36 is a cross-sectional view of the child seat shown in FIG. 35 taken along U7-U7.

[0150] FIG. 37 is an enlarged view of area A in FIG. 36.

[0151] FIG. 38 is an enlarged view of area B in FIG. 37.

[0152] FIG. 39 is a schematic structural view of a bracket assembly and a second adjustment column according to some embodiments of the present application.

[0153] FIG. 40 is an enlarged view of area C in FIG. 39.

[0154] FIG. 41 is a schematic structural view of a mounting base according to some embodiments of the present application.

[0155] FIG. 42 is a schematic structural view of a height adjustment mechanism and a first adjustment column according to some embodiments of the present application. [0156] FIG. 43 is a schematic structural view of the height adjustment mechanism and the first adjustment column shown in FIG. 42 with a fixed base being hidden.

[0157] FIG. 44 is an exploded view of the mounting base shown in FIG. 41.

[0158] FIG. 45 is a front view of the child seat shown in FIG. 34.

[0159] FIG. 46 is a partial cross-sectional view of the child seat shown in FIG. 45 taken along U8- U8.

[0160] FIG. 47 is a partial cross-sectional view of the child seat shown in FIG. 45 taken along U9-

U₉.

[0161] FIG. 48 is a schematic structural view of an adjustment base according to some embodiments of the present application.

[0162] FIG. 49 is an exploded view of a rotation adjustment mechanism according to some embodiments of the present application.

[0163] FIG. 50 is a schematic structural view of a seat assembly according to some embodiments of the present application.

[0164] FIG. 51 is a schematic structural view of a bracket assembly and a seat adjustment device according to some embodiments of the present application.

[0165] FIG. 52 is a partial view cross-sectional view of a detachment locking member of the child seat shown in FIG. 45.

[0166] FIG. 53 is a partial cross-sectional view of the child seat shown in FIG. 45 taken along U8- U8.

[0167] FIG. 54 is an enlarged view of area D in FIG. 53.

[0168] FIG- 55 is a schematic structural view of the child seat shown in FIG. 34 from another perspective.

[0169] FIG. 56 is an enlarged view of area E in FIG. 55.

[0170] FIG. 57 shows a schematic structural view of the tray shown in FIG. 54 and an enlarged view showing a part of structure of the tray shown in FIG. 55.

[0171] FIG. 58 is a schematic structural view of the seat shown in FIG. 55.

[0172] FIG. 59 is a schematic structural view of a child seat according to some embodiments of the present application, with the child seat being in a first use mode.

[0173] FIG. 60 is another schematic structural view of a child seat according to some embodiments of the present application, with the child seat being in a second use mode.

[0174] FIG. 61 is another schematic structural view of a child seat according to some embodiments of the present application, with the child seat being in a third use mode.

[0175] FIG. 62 is another schematic structural view of a child seat according to some embodiments of the present application, with the child seat being in a fourth use mode.

[0176] FIG. 63 is a partial exploded view of the child seat shown in FIG. 59. [0177] FIG. 64 shows a rear view of the child seat shown in FIG. 59 and an enlarged view of a first connecting member, with the seat detachment mechanism being in an unlocking state.

[0178] FIG. 65 shows a rear view of the child seat shown in FIG. 59 and an enlarged view of the first connecting member, with the seat detachment mechanism being in a locking state.

[0179] FIG. 66 is a schematic structural view of a first connecting member according to some embodiments of the present application.

[0180] FIG. 67 shows a right side view of the child seat shown in FIG. 59 and an enlarged view of a second connecting member.

[0181] FIG. 68 is a cross-sectional view of the child seat shown in FIG. 59 and an enlarged view of a connection between the legs and the leg base, with a folding locking mechanism being in a locking state.

[0182] FIG. 69 is an enlarged view of area F in FIG. 68.

[0183] FIG. 70 is a cross-sectional view of the child seat in FIG. 59, with the folding locking mechanism being in an unlocking state.

[0184] FIG. 71 is an enlarged view of arear J in FIG. 70.

[0185] FIG. 72 is a schematic structural view of the child seat in FIG. 59 from another perspective. [0186] FIG. 73 shows a schematic structural view of the chair body according to some embodiments of the present application with a first seat plate being omitted, and shows an enlarged view of a leg base and a second seat plate.

[0187] FIG. 74 is a schematic structural view of a first seat plate according to some embodiments of the present application.

[0188] FIG. 75 shows a cross-sectional view of the chair body according to some embodiments of the present application, an enlarged view of a rotation adjustment mechanism, and shows an enlarged view of a connection between a first seat plate and a second seat plate.

[0189] FIG. 76 shows a schematic structural view of the chair body according to some embodiments of the present application with a positioning operating member being omitted, and shows an enlarged view of a place for connecting to the positioning operating member, and

[0190] FIG. 77 is a schematic structural view of a positioning operating member according to some embodiments of the present application.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0191] First Embodiment

Referring to FIG. 1, a perspective view of a chair (more specifically a high chair 1000) according to an embodiment of the present application is shown. The chair is equipped with a height adjustment mechanism 2 and a folding mechanism 7 according to an embodiment of the present application. In the following, while describing the structure of the high chair 1000, the structures of the height adjustment mechanism 2 and the folding mechanism 7 are also described.

[0192] Referring to FIG. 1, a high chair 1000 includes a seat assembly too and a bracket assembly

200. The seat assembly too is attached to the bracket assembly 200. The seat assembly too provides a sitting position for children, and the bracket assembly 200 is used to support the seat assembly too at a certain height. The height of at least one of the seat assembly too and the bracket assembly 200 is adjustable such that the height of the high chair 1000 is adjustable to adapt to different table heights at home.

[0193] Referring to FIG. 1, a seat assembly too includes a seat 1. The seat 1 has a surface for a child to sit on. In some embodiments, the seat 1 can be selectively equipped with a tray 12, a backrest 13, a footrest 14, a safety belt 16, etc. The bracket assembly 200 includes a base 5 and a plurality of legs 6. Upper ends of the plurality of legs 6 are pivotally connected to the base 5, and lower ends of the plurality of legs 6 are supported by the ground. It should be noted that the number of the plurality of legs 6 of the bracket assembly 200 is not limited to the four shown in the figures. In alternative embodiments, there may be, for example, three or more legs. Additionally, in some alternative embodiments, every two legs of the plurality of legs 6 may be pivotally connected to the base 5 through a same pivot shaft in groups of two. Additionally, in alternative embodiments, the upper ends of the plurality of legs 6 are not limited to being pivotally connected to the base 5, for example, the upper ends of each of the legs 6 are slidably connected to the base 5, and thus is extendable or retractable in a horizontal direction.

[0194] Referring to FIG. 1, the seat 1 is indirectly mounted on the base 5 through the height adjustment mechanism 2, so that the seat assembly too is supported by the bracket assembly 200. Of course, the mounting manners of the seat assembly too and the bracket assembly 200 are not limited to the above examples. For example, in some alternative embodiments, the seat assembly too may not be provided with the height adjustment mechanism 2, and the seat 1 may be directly connected to the base 5 in a relatively rotatable manner, or the seat 1 may be directly connected to the base 5 in a fixed manner. In some alternative embodiments, the base 5 may not be provided, and the upper ends of the plurality of legs 6 are directly connected to the seat 1.

[0195] The height adjustment of the high chair 1000 can be achieved in a variety of ways. For example, in some embodiments not shown, the length of each leg 6 itself is telescopic, so that the height of the bracket assembly 200 is adjustable, thereby making the height of the high chair 1000 adjustable. More specifically, each leg 6 includes, for example, at least two telescopic legs that are sleeved in sequence and a locking mechanism for unlocking or locking the relative movement of these telescopic legs. When it is necessary to adjust the height of the high chair 1000, the telescopic legs are unlocked, then the length of the telescopic legs is adjusted to a desired length, and finally, the telescopic legs are locked again.

[0196] Continuing to refer to FIG. 1, in some embodiments, the height adjustment mechanism 2 can be used to adjust the height of the seat i and the height of the high chair 1000. The height adjustment mechanism 2 may include a supporting base 27, two adjustment members 21 oppositely arranged in a first horizontal direction Hi, and the above-mentioned seat 1 (which may also be called a movable member). An upper end of each adjustment member 21 is movably connected to the seat 1, and a lower end of each adjustment member 21 is pivotally connected to the supporting base 27 through the first shaft 31. The supporting base 27 supports the seat 1 through the two adjustment members 21. An axial direction of the first shaft 31 is perpendicular to the first horizontal direction Hi. In the embodiment shown in FIG. 1, the supporting base 27 is rotatably mounted on the base 5. By controlling a rotation of the supporting base 27 relative to the base 5, an orientation of the seat 1 can be easily adjusted without moving the high chair 1000 as a whole. In some alternative embodiments, the base 5 can be used as a supporting base 27 pivotally connected to each adjustment member 21, that is, the base 5 and the supporting base 27 are integral piece and fixed to each other. In some embodiments, the base 5 and the supporting base 27 are formed integrally, for example. Accordingly, the height adjustment mechanism 2 may not additionally provide with a separate supporting base 27 in addition to the base 5.

[0197] Referring the partial front views of the high chair 1000 shown in FIGS. 2 and 3, connection between the upper ends of the two adjustment members 21 and the seat 1 forms two connecting points Pi and P2. The connecting point Pi corresponds to a connection point between one adjustment member 21 and the seat 1, and the connecting point P2 corresponds to a connection point between another adjustment member 21 and the seat 1 By controlling the two adjustment members 21 to rotate around the corresponding first shaft 31, the positions of the two connecting points Pi and P2 relative to the respective corresponding adjustment members 21 are not changed, but the positions of the two connecting points Pi and P2 relative to the seat 1 are changed. More specifically, the two connecting points Pi and P2 located at the upper ends of the two adjustment members 21 move away from or close to each other along the seat 1 in the first horizontal direction Hi. As each adjustment member 21 rotates, the positions of the connecting points Pi and P2 between each adjustment member 21 and the seat 1 may be correspondingly raised or lowered in a vertical direction V, thereby raising or lowering the seat 1. In some embodiments, during the rotation of the two adjustment members 21 around the corresponding first shaft 31, the distance between the upper ends of the two adjustment members 21 is always less than the distance between the lower ends of the two adjustment members 21. That is, the two adjustment members 21 support the seat 1 in an arched posture, so that a reliable support for the seat 1 is provided. In this case, when the upper ends of the two adjustment members 21 move away from each other, the seat 1 is raised, and when the upper ends of the two adjustment members 21 move close to each other, the seat 1 is lowered.

[0198] Continuing to refer to FIGS. 2 and 3, in some embodiments, the seat 1 has a first height Gi and a second height G2 relative to the supporting base 27, with the first height Gi being greater than the second height G2. A vertical distance of the connection of the adjusting member 21 and the seat 1 relative to the first axis 31 serves as a reference for the height of the seat 1 relative to the supporting base 27. When the seat 1 is at the first height Gi, the connecting points Pi, P2, P3, and P4 for the supporting base 27, the seat 1, and the two adjustment members 21 define a first area Si (enclosed by broken lines in FIG. 2). As mentioned above, two connecting points Pi and P2 are formed at the connection between the seat 1 and the two adjustment members 21. The connecting points P3 and P4 are formed at the connection between the supporting base 27 and the two adjustment members 21. In some embodiments, the two first shaft 31 correspond to the connecting points P3 and P4. When the seat 1 is at the second height G2, the connecting points Pi to P4 for the supporting base 27, the seat 1, and the two adjustment members 21 define a second area S2 (enclosed by broken lines in FIG. 3). The first area Si is greater than the second area S2. That is, when the height of the seat 1 relative to the supporting base 27 is reduced, the area defined by the connecting points Pi, P2, P3, and P4 for the supporting base 27, the seat 1, and the two adjustment members 21 tend to be reduced. On the contrary, when the height of the seat 1 relative to the supporting base 27 in increased, the area defined by the connecting points Pi, P2, P3, and P4 for the supporting base 27, the seat 1, and the two adjustment members 21 tend to be increased.

[0199] It should be noted that in some alternative embodiments, when the two adjustment members 21 are controlled to rotate around the corresponding first shaft 31, the positions of the two connecting points Pi and P2 relative to the seat 1 are not changed, but the positions of the two connecting points Pi and P2 relative to their corresponding adjustment members 21 are changed. In this way, the seat 1 can also be raised or lowered.

[0200] Referring to FIGS. 4 and 5, FIG. 4 shows a rear perspective view of the high chair 1000, and FIG. 5 is a cross-sectional view of the high chair 1000 shown in FIG. 2 taken along U1-U1. The high chair 1000 may further include a rotation adjustment mechanism for locking the relative positions of the supporting base 27 and the base 5. In some embodiments, the rotation adjustment mechanism includes a third locking member 275 to prevent the seat 1 from rotating arbitrarily when the child is having dinner. In some embodiments, the third locking member 275 is movably mounted on the supporting base 27 in the vertical direction V. The supporting base 27 has an outwardly protruding operating portion 2751, and the supporting base 27 has a longitudinal hole 270 for the operating portion 2751 to pass through. The base 5 is provided with one, two or more positioning holes 50 along a circumferential direction. The plurality of positioning holes 50 are, for example, evenly arranged in the circumferential direction, and an axial direction of each positioning hole 50 is parallel to the vertical direction V. When the third locking member 275 is inserted into one of the positioning holes 50, the supporting base 27 is locked in a position. When it is necessary to adjust an orientation of the seat 1, the third locking member 275 is lifted upward until it exits the positioning hole 50 into which the third locking member 275 is currently inserted, and then the seat 1 is rotated to a suitable position, and then the third locking member 275 is inserted into another positioning hole 50. In some alternative embodiments, the positions of the third locking member 275 and the positioning hole 50 on the supporting base 27 and the base 5 maybe interchanged. In some alternative embodiments, the third locking member 275 is movable in the horizontal direction, so as to be inserted into or exited from the horizontally extending positioning hole 50. It should be noted that in some alternative embodiments, the above-mentioned adjustment member 21 may not be provided between the supporting base 27 and the seat 1. The supporting base 27 may be integrated with the seat 1, or the supporting base 27 may be attached to the seat 1 by, for example, screws, rivets, snaps, etc. At this time, the high chair 1000 may also be equipped with a third locking member 275 to allow the circumferential position of the seat 1 relative to the base 5 to be adjustable.

[0201] Referring to FIG. 5, in some embodiments, a fourth elastic element 44 may be disposed between the supporting base 27 and the third locking member 275. The fourth elastic element 44 is used to drive the third locking member 275 to be engaged with the positioning hole 50, which may prevent the third locking member 275 from being accidentally touched and exited the positioning hole 50. Of course, in some alternative embodiments, the fourth elastic element 44 may not be provided. It should be understood that when the third locking member 275 is disposed on the base 5, the fourth elastic element 44 is disposed between the base 5 and the third locking member 275.

[0202] Referring to FIGS. 4 and 6, FIG. 6 is a cross-sectional view of the high chair 1000 shown in FIG. 5 taken along U2-U2. In some embodiments, the supporting base 27 is provided with two supporting members 271 oppositely arranged in the first horizontal direction Hi. The two supporting members 271 are in one-to-one correspondence with the two adjustment members 21. Upper ends of the two supporting members 271 are respectively pivotally connected to lower ends of the two adjustment members 21 by the first shaft 31. As can be seen from FIG. 6, the two supporting members 271 extend upward from the supporting base 27, and the distance between the upper ends of the two supporting members 271 is greater than the distance between the lower ends thereof, which is beneficial to reducing a radial size of the supporting base 27. In some embodiments, the two supporting members 271 and the supporting base 27 may be integrally formed.

[0203] Referring to the perspective view of the adjustment member 21 shown in FIG. 7, in some embodiments, each adjustment member 21 includes a pair of connecting arms 211 arranged oppositely in a second horizontal direction H2 perpendicular to the first horizontal direction. Hi (see FIG. 1). Upper ends of the pair of connecting arms 211 are movably connected to the seat 1, and lower ends of the pair of connecting arms 211 are pivotally connected to the supporting base 27 through the first shaft 31. At least one of two opposite surfaces of the pair of connecting arms 211 is provided with a sliding slot 2111, and the seat 1 is provided with a boss 102 slidably cooperated with the sliding slot 2111 (see FIG. 9). Through the fitting of the sliding slot 2111 with the boss 102, a movement range of each adjustment member 21 relative to the seat 1 is limited. In some embodiments, each adjustment member 21 further includes a side plate 212 connected between a pair of connecting arms 211, which is beneficial to a rotational consistency of the pair of connecting arms 211.

[0204] Referring to FIGS. 6 to 8, FIG. 8 shows a perspective view of the supporting base 27. In some embodiments, in a pair of corresponding supporting members 271 and adjustment members

21, the upper end of the supporting member 271 is provided with a mounting hole 2710, and the lower end of the adjustment member 21 is provided with a first shaft 31 pivotally connected to the mounting hole 2710, so that the adjustment member 21 is pivotally connected to the supporting member 271 through the first shaft 31. In some alternative embodiments, the positions of the mounting hole 2710 and the first shaft 31 on the upper end of the supporting member 271 and on the lower end of the adjustment member 21 may be interchanged.

[0205] Referring to FIGS. 7 and 8, in some embodiments, an angle limiting mechanism 28 is disposed between the adjustment member 21 and the supporting member 271. The angle limiting mechanism 28 is used to limit a rotation angle range of the adjustment member 21, so as to ensure that the height adjustment operation of the seat 1 is controllable. In some embodiments, the angle limiting mechanism 28 may include a first arc-shaped groove 281 and an elastic telescopic pin 282. The first arc-shaped groove 281 is disposed on a hole wall of the mounting hole 2710 and extends in the circumferential direction. The elastic telescopic pin 282 is disposed on the first shaft 31 and is telescopic along the radial direction of the first shaft 31. When the first shaft 31 is mounted in the mounting hole 2710, the elastic telescopic pin 282 is inserted into the first arc-shaped groove 281. In order to facilitate the insertion of the elastic telescopic pin 282 into the first arc-shaped groove 281, the hole wall of the mounting hole 2710 may be provided with an inclined surface 2712, and the inclined surface 2712 is used to guide the elastic telescopic pin 282 to be inserted into the first arcshaped groove 281. Of course, in other embodiments, the angle limiting mechanism 28 may also have other implementations, as long as it can limit the rotation angle range of the adjustment member 21. [0206] Referring to FIG. 6, the height adjustment mechanism 2 may further include two first locking members 22, and the two first locking members 22 are in one-to-one correspondence with the two adjustment members 21. Each first locking member 22 is used to lock the relative position of the corresponding adjustment member 21 and the seat 1, thereby locking the seat 1 at the adjusted height. In some embodiments, each first locking member 22 maybe directly or indirectly disposed on the upper end of the corresponding adjustment member 21. When each adjustment member 21 moves into position, each first locking member 22 is engaged into the slot 101 on the seat 1, thereby locking the relative position of each adjustment member 21 and the seat 1.

[0207] Referring to FIGS. 6 and 9, FIG. 9 shows a bottom perspective view of the seat 1 of the high chair 1000. In some embodiments, the bottom of the seat 1 may be provided with a plurality of slots 101, and the plurality of slots 101 is arranged along the first horizontal direction Hi. A first part (two, three or more slots 101) of the plurality of slots 101 corresponds to one of the first locking members

22, and a second part (two, three or more slots 101) of the plurality of slots 101 corresponds to another first locking member 22. The first part of the slot 101 and the second part of the slot 101 are arranged symmetrically. Each first locking member 22 moves in the vertical direction V to be engaged with or disengaged from the corresponding engaging groove 101 at the bottom of the seat 1 respectively. When the first locking member 22 is engaged with the slot 101, the first locking member 22 is in a locking position. When the first locking member 22 is disengaged from the slot, the first locking member 22 is in an unlocking position. In addition, each first locking member 22 moves in the first horizontal direction Hi to correspond to different slots 101. In alternative embodiments, the arrangements of the plurality of slots 101 and the movement of the first locking member 22 may also be implemented in other ways. For example, a plurality of slots 101 may be disposed on a vertically extending side wall (such as a side wall 11) of the seat 1, and the first locking member 22 is engaged with or disengaged from the slots 101 by moving in the second horizontal direction H2.

[0208] Referring to FIGS. 6 and 11, FIG. 11 shows a top perspective view of some components of the height adjustment mechanism 2. In some embodiments, the height adjustment mechanism 2 also includes two slide blocks 23 slidably cooperated with the seat 1. The two slide blocks 23 are respectively pivotally connected to the upper ends of the two adjustment members 21 through a second shaft 32 parallel to the first shaft 31. In some embodiments, the two second shafts 3 2 correspond to the connecting points Pi and P2. In some embodiments, each slide block 23 is provided with a through hole 2301 respectively, an upper end of the connecting arm 211 of each adjustment member 21 is provided with a through hole 2110, and each second shaft 32 extends through the corresponding through hole 2301 and the through hole 2110. The two slide blocks 23 are in one-to- one correspondence with the two first locking members 22, and each first locking member 22 is movably connected to the corresponding slide block 23. Referring to FIG. 6, when each first locking member 22 is disengaged from the corresponding slot 101, the two adjustment members 21 are controlled to rotate in opposite directions around their respective first shaft 31, and the upper ends of the two adjustment members 21 drive the two slide blocks 23 to move away from or close to each other in the first horizontal direction Hi via the second shaft 32, and the seat 1 is raised or lowered accordingly. When the height of the seat 1 is adjusted to a suitable position, each first locking member 22 is moved along the vertical direction V relative to the corresponding slide block 23 to be engaged with the corresponding slot 101, that is, the two slide blocks 23 are locked, so that the relative positions of each adjustment member 21 and the seat 1 are locked, and the seat 1 is locked at the adjusted height position. In some embodiments, each slide block 23 has a cavity 230 (see FIG. 13), each first locking member 22 is mounted in the corresponding cavity 230, and the cavity 230 defines the movement of the first locking member 22 relative to the corresponding slide block 23 in the vertical direction V.

[0209] Referring to FIGS. 6, 9, 11 and 12, FIG. 12 shows a bottom perspective view of the high chair 1000. In some embodiments, the bottom of the seat 1 includes, for example, two side walls 11 (shown in FIGS. 9 and 12) oppositely arranged in the second horizontal direction H2 and a cover 15 covering a bottom of the two side walls 11. A plurality of slots 101 are located between the two side walls 11. Two ends of the cover 15 respectively extend through a pair of connecting arms 211 of each adjustment member 21 and are bent upward. A fastener (not shown in figures) extends through a hole 151 (FIG. 12) on the cover 15 and is connected to a hole 105 (FIG. 9) of the seat 1. The bottom surface of the seat 1, the two side walls 11, and the cover 15 are enclosed together to form a receiving cavity 10 (see FIG. 6). Two slide blocks 23 and two first locking members 22 are located in the receiving cavity 10. As mentioned above, the two slide blocks 23 can move along the first horizontal direction Hi along with the two first locking members 22. The second shaft 32 corresponding to each slide block 23 is extended out of the two side walls 11 and is pivotally connected to the through hole 2110 at the upper end of the corresponding adjustment member 21. Each side wall 11 of the receiving cavity 10 is provided with a first elongated hole 110 corresponding to the two ends of each second shaft 32 (see FIGS. 9 and 12). The first elongated hole 110 is extended along the first horizontal direction Hi. By mounting each slide block 23 and each first locking member 22 in the receiving cavity 10, interference of the external environment with the normal movement of each slide block 23 can be prevented. The fitting of each second shaft 32 with the corresponding first elongated hole 110 also limits the movement range of each adjustment member 21 relative to the seat 1.

[0210] Referring to FIG. 10, a perspective view of the first locking member 22 and related parts is shown. The height adjustment mechanism 2 can also include a first elastic element 41 used to drive each first locking member 22 to be engaged with the seat 1. The first elastic element 41 may include a spring mounted in the cavity 230 (see FIG. 13) of each slide block 23, and the spring is clamped between the slide block 23 and the corresponding first locking member 22.

[0211] Referring to FIGS. 6, 10 and 11, in order to facilitate the operation of each first locking member 22, in some embodiments, the height adjustment mechanism 2 further includes two first driving members 24 in one-to-one correspondence with the two first locking members 22. Each first driving member 24 is drivingly connected to the corresponding first locking member 22, so that when subjected to an external force Fl, each first driving member 24 moves in the first horizontal direction Hi and drives the corresponding first locking member 22 to move downward, so as to be disengaged from the slot 101 of the seat 1.

[0212] Converting the horizontal movement of each first driving member 24 into the downward movement of the corresponding first locking member 22 can be implemented in various ways. Referring to FIGS. 10, 13 and 14, in some embodiments, each first locking member 22 has a through hole 220 (see FIG. 14), a first pin 221 is mounted in the through hole 220, and the first pin 221 is parallel to the first shaft 31. In some embodiments, each slide block 23 has an elongated hole 2302 extending along the vertical direction V (see FIG. 14), and the first pin 221 is slidably cooperated with the elongated hole 2302. Each first driving member 24 is respectively provided with a hole 240, and each first pin 221 extends through the corresponding hole 240. Each hole 240 has a driving slope 241 (see FIG. 10), and the driving slope 241 abuts against the corresponding first pin 221. Referring to FIGS. 6 and 10, when each first driving member 24 is subjected to external force Fl and moves in the first horizontal direction Hi, its driving slope 241 pushes the corresponding first pin 221 to move downward, and each first pin 221 drives the corresponding first locking member 22be disengaged from the slot 101. When the external force Fl is removed, the first elastic element 41 drives each first driving member 24 to move upward, so as to be engaged with the corresponding slot 101. In some alternative embodiments, the hole 240 can be designed as an oblique elongated hole. In this case, the first elastic element 41 can be omitted. By applying a force in a direction opposite to the direction of the above-mentioned external force Fl to each first driving member 24, the corresponding first pin 221 can be pushed to move upward, so that each first locking member 22 is engaged with the corresponding slot 101. In some alternative embodiments, the position of the first pin 221 on the first locking member 22 and the position of the hole 240 with the driving slope 241 on the first driving member 24 may be interchanged.

[0213] Referring to FIGS. 11 to 14, FIGS. 13 and 14 show exploded views of the high chair in two directions. In some embodiments, the height adjustment mechanism 2 may also include two first locking members 25 in one-to-one correspondence with the two first driving members 24, and each first locking member 25 is operably connected to the corresponding first driving members 24. The caregiver can use the two first unlocking members 25 to easily apply the above-mentioned external force Fl to each first driving member 24. In some embodiments, referring to FIGS. 11 and 13, an inner surface of the cover 15 is provided with two protrusions 152 spaced apart in the second horizontal direction H2, and the part of each first unlocking member 25 located in the receiving cavity 10 has an elongated hole 250, and the two protrusions 152 are respectively slidably cooperated with the elongated holes 250 of the two first unlocking members 25 to guide the two first unlocking members 25 to slide in the first horizontal direction Hi. In some embodiments, referring to FIG. 14, the cover 15 is provided with two through holes 150, each first unlocking member 25 includes an operating portion 252, and the operating portions 252 of the two first unlocking members 25 are respectively extended out of and slidably cooperated with the two through hole 150, so as to guide the two first unlocking members 25 to slide in the first horizontal direction Hi. The caregiver can conveniently apply the above-mentioned external force Fl to each first driving member 24 through the operating portion 252 of each first unlocking member 25 (Fig. 10). In some alternative embodiments, the height adjustment mechanism 2 may include an unlocking member 25, such as a knob, which is operably connected to both the two first driving members 24 to drive the two first driving members 24 to move in the first horizontal direction Hi.

[0214] Referring to FIG. 11, in some embodiments, each first unlocking member 25 is connected to the corresponding first driving member 24 through a first traction member 261, and each first unlocking member 25 drives the corresponding first driving member 24 to moves in the first horizontal direction Hi through the first traction member 261. The first traction member 261 may be a steel wire rope, a flexible belt, etc. An end of the first traction member 261 is connected to a mounting portion 242 (see FIG. 10) of the first driving member 24, and another end of the first traction member 261 is connected to a mounting portion 251 of the first unlocking member 25. In some embodiments, each first traction member 261 is provided with a protective jacket 262 on the outside. An end of the protective jacket 262 can be mounted on the mounting portion 231 of the slide block 23, and another end of the protective jacket 262 can be mounted on the protrusion 152.

[0215] The working process of the above-mentioned height adjustment mechanism 2 for adjusting the height of the seat 1 is described below with reference to FIGS. 6 and 11. Referring to FIGS. 6 and 10, the seat 1 is supported at a height by the height adjustment mechanism 2, and the two first locking members 22 are engaged with the corresponding slots 101. The caregiver applies an external force Fl to the operating portions 252 of the two first unlocking members 25, and the two first unlocking members 25 pull the two first driving members 24 to move toward each other in the first horizontal direction Hi through the two first traction members 261. The driving slopes 241 of the two first driving members 24 push the two first pins 221 to move downward, so that the two first locking members 22 move downward and are disengaged from the slot 101. At this time, the seat 1 is pressed downward or the seat 1 is pulled upward, while the seat 1 moves in the vertical direction, the two slide blocks 23 drive the two first locking members 22 to move close to or away from each other in the first horizontal direction Hi. When the height of the seat 1 is appropriate, the external force Fl is removed, and the two first locking members 22 automatically move upward under the action of the first elastic element 41 and are engaged with the slot 101, thereby locking the seat 1 in the adjusted position. When the two first locking members 22 move upward, they push the two first driving members 24 to return. The returning process of the two first driving members 24 can drive the two first locking members 22 to return.

[0216] It can be understood that under the action of the protective jacket 262, even if the first locking member 22 is engaged with a different slot 101, a release stroke of the first locking member 25 for unlocking the first locking member 22 is the same as a sliding distance of 261 of the first traction member 261m the protective jacket 262. More specifically, the protective jacket 262 is, for example, a rubber sleeve, and the movement of the two slide blocks 23 close to or away from each other in the first horizontal direction Hi may cause the protective jacket 262 to deform. The first traction member 261 is bent or straightened as a whole as the protective jacket 262 deforms, which does not affect the sliding stroke of the first traction member 261 within the protective jacket 262. Therefore, no matter which slot 101 the first locking member 22 is engaged with, the first traction member 261 can be pulled to drive the first driving member 24 to move when the first locking member 25 is operated. Similarly, when the external force is removed, the returning of the first locking member 22 may drive the first driving member 24 to return, and then the first traction member 261 may drive the first unlocking part 25 to return.

[0217] Referring to FIGS. 13 and 14, in some embodiments, the height adjustment mechanism 2 may also include a second elastic element 42, which is used to drive each first unlocking member 25 to return. In some embodiments, the second elastic element 42 includes, for example, two springs. The two springs are arranged in the receiving cavity 10 (see FIG. 6) and are clamped between the two first unlocking members 25. [0218] Referring to FIGS. 15 and 16, a perspective view of the high chair 1000 with the folding mechanism 7 being in different states is shown. In some embodiments, the upper end of each leg 6 is pivotally connected to the base 5. The folding mechanism 7 is used to change the state of the bracket assembly 200. In some embodiments, the folding mechanism 7 is connected to a plurality of legs 6, and adjusts the height of the base 5 by controlling the unfolding degree of the plurality of legs 6, thereby adjusting the height of the seat 1. In some embodiments, the plurality of legs 6 have a minimum unfolding degree and a maximum unfolding degree. Referring to FIG. 15, when the plurality of legs 6 is at the minimum unfolding degree, an acute angle formed by each leg 6 relative to the vertical direction reaches a minimum, corresponding to the maximum height of the base 5. On the contrary, referring to FIG. 16, when the plurality of legs 6 is at the maximum unfolding degree, an acute angle formed by each leg 6 relative to the vertical direction reaches a maximum, corresponding to the minimum height of the base 5. In some embodiments, when the plurality of legs 6 is at the minimum unfolding degree, the bracket assembly 200 is in the folded state. In some embodiments, the bracket assembly 200 can still stand on the ground when in the folded state. In some alternative embodiments, the plurality of legs 6 may also have one or more states between a maximum unfolding degree and a minimum unfolding degree, thereby allowing the base 5 to have multiple adjustment heights.

[0219] Referring to FIGS. 15 and 16, in some embodiments, the folding mechanism 7 may include an adjustment base 71 and a plurality of connecting members 72. The adjustment base 71 is slidably connected to the plurality of legs 6 through a plurality of connecting members 72, so that the adjustment base 71 can move along the vertical direction V to control each of the legs 6 to unfold or fold synchronously. In some alternative embodiments, the folding mechanism 7 maybe implemented in other ways.

[0220] The slidable connection of each connecting member 72 to the corresponding leg 6 can be implemented in various ways. Referring to FIG. 17, a bottom perspective view of the high chair is shown. In some embodiments, each connecting member 72 is pivotally connected to the adjustment base 71 through a third shaft 33, and each connecting member 72 is provided with a notch 721. Each leg 6 is provided with a sliding rail 61, and each connecting member 72 is slidably connected to the sliding rail 61 on the corresponding leg 6 through its notch 721. In some alternative embodiments, each connecting member 72 may include a sleeve structure that is sleeved on the corresponding leg 6 and is movable along the leg 6 itself.

[0221] Referring to FIG. 18, a cross-sectional view of the bracket assembly shown in FIG. 16 taken along U3-U3 is shown, with the bracket assembly being in an unfolded state. FIG. 19 shows a cross- sectional view of the bracket assembly shown in FIG. 18 with the bracket assembly being in a folded state. In some embodiments, at least one lock slot 62 is disposed on at least one leg 6. The folding mechanism 7 also includes at least one second locking member 73, which is used to be engaged with the locking groove 62 of the leg 6, so as to lock the relative position of the adjustment base 71 and at least one leg 6, and thus, to lock the base 5 at the adjusted height. In some embodiments, the folding mechanism 7 may include a plurality of second locking members 73, the plurality of second locking members 73 are in one-to-one correspondence with the plurality of legs 6, and each leg 6 is provided with at least one lock slot 62. Each second locking member 73 is used to be engaged with the lock slot 62 on the corresponding leg 6, so as to lock the relative position of the adjustment base 5 and each leg 6, and to more reliably lock the relative position of the adjustment base 71 and each leg 6.

[0222] Referring to FIGS. 18 and 19, in some embodiments, each leg 6 may be provided with two or more lock slots 62, and these lock slots 62 are spaced apart along the length direction L of the leg 6. When the plurality of second locking members 73 is engaged with the lock slots 62 at different positions, the base 5 is locked at different heights. In some embodiments, when each locking member 73 is respectively engaged with the lowermost lock slot 62, the bracket assembly 200 is in the folded state. The engagement of the locking member 73 with the lock slot 62 can prevent the plurality of legs 6 from being accidentally unfolded. In some alternative embodiments, only one lock slot 62 may be disposed on each leg 6.

[0223] Continuing to refer to FIG. 18, in some embodiments, each second locking member 73 corresponds to and is movably connected to each connecting member 72 in a one-to-one manner. More specifically, each second locking member 73 has a second elongated hole 731, and the second elongated hole 731 is sleeved on the third shaft 33 of the corresponding connecting member 72, which is beneficial to the compact structure of the folding mechanism 7. In some embodiments, each connecting member 72 has a groove 720 for the corresponding second locking member 73 to extend through, and the groove 720 defines a telescopic path of the second locking member 73.

[0224] Referring to FIGS. 17 and 18, in some embodiments, the folding mechanism 7 may also include at least one second unlocking member 74 and at least one second traction member 75. The at least one second unlocking member 74 is connected to the at least one second locking member 73 through the at least one second traction member 75 to drive the at least one second locking member 73 to be disengaged from the corresponding lock slot 62. In some embodiments, one the second unlocking member 74 is provided, and the number of the second traction members 75 is consistent with the number of the second locking members 73. The second unlocking member 74 synchronously drives the plurality of second locking members 73 to be disengaged from the corresponding lock slots 62 through the plurality of second traction members 75, thus simplifying the unlocking operation. In some alternative embodiments, the number of the second locking members 74 maybe consistent with the number of the second locking members 73, and each second locking member 74 independently drives the corresponding second locking member 73 via each second traction member 75.

[0225] Referring to FIGS. 17 and 18, in some embodiments, the folding mechanism 7 may also include at least one third elastic element 43. The at least one third elastic element 43 is used to drive at least one second locking member 73 to be engaged with the corresponding lock slot 62. In some embodiments, the number of the third elastic elements 43 is consistent with the number of the second locking members 73, and the third elastic elements 43 can directly or indirectly abut against the second locking members 73 to apply an elastic force that causes the second locking member 73 to be inserted into the corresponding lock slot 62 to the second locking members 73.

[0226] Referring to FIGS. 17-21, FIGS. 20 and 21, top perspective views of some parts of the bracket assembly are shown. In some embodiments, the adjustment base 71 includes, for example, an upper housing 711 and a lower housing 712, which are butted together and define an inner cavity 70 therebetween. Each second traction piece 75 is located in the inner cavity 70, and each second locking member 73 is telescopic relative to the inner cavity 70. The second lock release component 74 is a knob, which can be mounted on the lower housing 712. The second unlocking member 74 has second arc-shaped grooves 740, the number of which corresponding to the number of the second traction members 75. Each second arc-shaped groove 740 spirally extends in the circumferential direction, so that a first end of each second arc-shaped groove 740 is close to a center M of the second unlocking member 74, a second end of each second arc-shaped groove 740 is close to an outer periphery of the second unlocking member 74. Each second traction member 75 is slidably connected to at least one second arc-shaped groove 740 through a second pin 7521.

[0227] Referring to FIGS. 18, 19 and 20, when the second pin 7521 of each second traction member 75 is located at the second end of the corresponding second arc-shaped groove 740, each second locking member 73 is engaged with the corresponding lock slot 62 under the action of the third elastic member 43, so that the position of the adjustment base 71 relative to each leg 6 is locked, and the height of the base 5 is locked. When it is necessary to adjust the position of the adjustment base 71, a torque T shown by the arrow in FIG. 17 is applied to the operating portion 741 of the second unlocking member 74, the second unlocking member 74 is rotated and drives each second pin 7521 to move toward the center of the second unlocking member 74 through a groove wall of the second arc-shaped grooves 740, and the third elastic element 43 is compressed. When each second pin 7521 is located at the first end of the corresponding second arc-shaped groove 740, each second locking member 73 is disengaged from the corresponding lock slot 62, and the adjustment base 71 can be moved. When the adjustment base 71 moves to an appropriate position, the above-mentioned torque T is released, and each second locking member 73 is automatically engaged with the corresponding lock slot 62 under the action of the third elastic element 43, and the second unlocking member 74 is driven to return by the fitting of the second pin 7521 with the second arc-shaped groove 740. In some alternative embodiments, a torsion spring for returning the second unlocking member 74 may also be mounted in the adjustment base 71.

[0228] Referring to FIGS. 18 to 21, in some embodiments, each second traction member 75 may include a linking member 751 and a second driving member 752 (see FIG. 18). A first end of the linking member 751 and the corresponding second locking member 73 are pivotally connected through a fourth shaft 34, and a second end of the linking member 751 and a first end of the second driving member 752 are pivotally connected through a fifth shaft 35. The second end of the second driving member 752 is connected to the second unlocking member 74. More specifically, the second end of the second driving member 752 is connected to the second arc-shaped groove corresponding to the second unlocking member 74 through the second pin 7521. In some embodiments, each third elastic element 43 may be mounted between the second driving member 752 and the upper housing 711. Of course, in other embodiments, each second traction member 75 may also have other implementations, and the second traction member 75 may be a flexible cable, for example.

[0229] Referring to FIG. 17, in some embodiments, the base 5 is made of plastic, for example, and a reinforcing sheet 51 may be mounted on the bottom of the base 5. The reinforcing sheet 51 is, for example, a metal sheet (e.g., an iron sheet), and is used to strengthen the structural strength of the base 5. The reinforcing piece 51 includes a plurality of pivot seats 511, and the upper ends of the plurality of legs 6 are pivotally connected to the plurality of pivot seats 511.

[0230] Referring to FIGS. 16 and 22, FIG. 22 shows a perspective view of another use mode of the high chair 1000. In some embodiments, each leg 6 may include an upper leg (which may also be referred to as a first leg) 601, a lower leg (which may also be referred to as a second leg) 602 and a foot 603 that are detachably connected. More specifically, when upper leg 601 and lower leg 602 are connected together, leg 602 is mounted on the bottom of lower leg 602. When the lower leg 602 is removed from the upper leg 601, the foot 603 is removed from the bottom of the lower leg 602, and then the foot 603 is mounted on the bottom of the upper leg 601. Therefore, the bracket assembly 200 can provide more height options for the base 5.

[0231] Referring to FIGS. 16 and 22, in some embodiments, the sliding rail 61 is disposed on the upper leg 601, and the upper leg 601, the lower leg 602 and the foot 602 are detachably connected, for example, by screwing or snapping. In this way, after the lower leg 602 is removed, the folding mechanism 7 can still work normally.

[0232] Referring to FIG. 13, in some embodiments, the lower end of each sliding rail 61 may be provided with a hooking portion 610, and the hooking portion 610 may be detachably connected to a storage bag 8. The storage bag 8 can provide additional storage space for the high chair.

[0233] It should be noted that the high chair 1000 according to embodiments of the present application can selectively equipped with one or all of the above-mentioned height adjustment mechanism 2 and folding mechanism 7. In some high chairs 1000 with both the height adjustment mechanism 2 and the folding mechanism 7, the height adjustment operations for the height adjustment mechanism 2 and the folding mechanism 7 do not affect each other, which provides the high chair 1000 with more height adjustment possibilities.

[0234] It should be noted that the height adjustment mechanism 2 according to embodiments of the present application is not limited to being applied to the high chair 1000. By replacing the seat 1 of the height adjustment mechanism 2 with any suitable movable member, the height adjustment mechanism 2 can be applied to any suitable device. In addition, the folding mechanism 7 according to embodiments of the present application is not limited to being applied to the high chair 1000, and can also be applied to any suitable device, such as a foldable table.

[0235] It should be noted that, unless otherwise clearly stated and defined, orientation terms "horizontal" and "vertical" in the embodiments of the present application are based on the orientation of the high chair when it is in normal use, and the directions of the “first horizontal direction”, “second horizontal direction” and “vertical direction” are schematically shown by arrows Hi, H2 and V in figures. These directional terms are only used to make the description of the embodiments of the present application clearer and are not used to unduly limit the protection scope of the present application.

[0236] Second Embodiment

FIGS. 23 to 26 show a perspective view of a carrier according to an embodiment of the present application and a cross-sectional view of a bracket assembly 300 according to an embodiment of the present application. As shown in figures, specifically, a high chair 1000 (also called a child seat, a child dining chair, or a chair) is used as an example to illustrate the carrier. The high chair 1000 includes a bracket assembly 300 (also called a leg folding structure) according to an embodiment of the present application and a seat 1 (also called a child seat) mounted on the bracket assembly 300. The bracket assembly 300 can adjust a state of the high chair 1000 by changing its own state. For example, when the bracket assembly 300 is in an unfolded state (see FIG. 23), the high chair 1000 is also in an unfolded state; and when the bracket assembly 300 is in a folded state (see FIG. 25), the high chair 1000 is also in a folded state. In some alternative embodiments, the bracket assembly 300 may also have at least one intermediate state between the unfolded state and the folded state. It can be understood that when the bracket assembly 300 is in different states, the seat 1 is supported at different heights to adapt to different usage scenarios. It can be understood that in some alternative embodiments, the type of the high chair 1000 is not limited to the child seat illustrated in the embodiments of the present application, and may be, for example, a table, a tall stool applied to a bar counter, a tripod for supporting a camera, etc.

[0237] Referring to FIGS. 24 and 26, the bracket assembly 300 may include a base (which may also be called a supporting base) 5, a plurality of legs 6, a first sliding member 761 and a plurality of linking members 762. The first sliding member 761 and the linking member 762 can be used as part of the folding mechanism for opening or folding the plurality of legs 6.

[0238] Referring to FIGS. 23 and 25, the seat 1 is mounted on the base 5. In some embodiments, the seat 1 is relatively rotatably connected to the base 5, for example, through a bottom turntable 100a, so that an orientation of the seat 1 is allowed to be adjusted without rotating the entire high chair 1000. A locking device (not shown in figures) may also be provided between the seat 1 and the base 5. The locking device is used to lock the relative rotation of the seat 1 and the base 5 to maintain the seat 1 in the adjusted orientation. In some alternative embodiments, the seat 1 is fixedly connected to the base 5 and thus, cannot be rotated relative to the base 5.

[0239] An exemplary embodiment of the base 5 is shown in an exploded view of the bracket assembly 300 shown in FIG. 27. The base 5 includes, for example, an upper housing 501, a middle housing 503, and a lower housing 502. The upper housing 501 and the lower housing 502 are connected for example, through a fastener (not shown in figures), and define a receiving cavity 5001. The middle housing 503 is located in the receiving cavity 5001, for example. In some embodiments, the middle housing 503 has, for example, a portion clamped between the upper housing 501 and the lower housing 502, and the fastener used to connect the upper housing 501 to the lower housing 502 may also extend through the portion the middle housing 503 that is clamped between the upper housing 501 and the lower housing 502. In other embodiments, the middle housing 503 may be connected to one of the upper housing 501 and the lower housing 502, for example, by snap-fitting or a fastener.

[0240] The upper housing 501 faces the seat 1. In some embodiments, the upper housing 501 has, for example, a central hole 5010, the middle housing 503 has, for example, a central hole 5030, and the bottom turntable 100a of the seat 1, for example, is connected to the central hole 5010 and the central hole 5030. A middle portion of the middle housing 503 (or called a middle portion of the base 5) has a hollow cylindrical column portion 50311 extending in the vertical direction V. The column portion 50311 is coaxial with the central hole 5030, and a slideway 5031 is formed on an outer peripheral wall of the column portion 50311, and the slideway 5031 is located inside the receiving cavity 5001. In this embodiment, when the high chair 1000 is in normal use, the vertical direction V corresponds to, for example, a vertical direction (or height direction) perpendicular to the ground. More specifically, the column portion 50311 extends downward in the vertical direction V. A plurality of mounting bases 5032 may be disposed on the outer periphery of the middle housing 503, and each mounting base 5032 has a pivot hole 50320. For example, the lower housing 502 has a plurality of holes 50201, and the plurality of holes 50201 are in one-to-one correspondence with the plurality of mounting bases 5032.

[0241] Referring to FIGS. 24 and 26, the plurality of legs 6 are respectively pivotally connected to the base 5, and the slideway 5031 is located in the middle of the plurality of legs 6. The upper end of each leg 6 extends through the hole 50201 of the lower housing 502, and then is pivotally connected to the pivot hole 50320 of the mounting base 5032 through a pivot shaft 625. It can be understood that each leg 6 can rotate about the pivot shaft 625, and thus a size of the hole 50201 should not interfere with the rotation of the leg 6. The lower ends of the plurality of legs 6 are adapted to be supported by the ground.

[0242] Referring to FIG. 24, when the plurality of legs 6 pivot in directions away from each other to a maximum unfolding degree, the bracket assembly 300 is in the unfolded state. Referring to FIG. 26, when the plurality of legs 6 are pivoted in directions close to each other to a minimum unfolding degree the bracket assembly 300 is in the folded state. In some embodiments, the bracket assembly 300 can still stand on the ground when in the folded state. In some embodiments, the plurality of legs 6 may also have one or more states between the maximum unfolding degree and the minimum unfolding degree. The height of the base 5 changes with the unfolding degree of the plurality of legs 6, thereby providing the seat 1 with various support heights.

[0243] As can be seen from FIG. 23 and FIG. 25, specifically, the bracket assembly 300 in this embodiment includes four legs 6. It can be understood that in some alternative embodiments, the number of legs 6 of the bracket assembly 300 is not limited to four, and the number of legs 6 maybe, for example, three or more. Additionally, in some alternative embodiments, the plurality of legs 6 may be pivotally connected to the base 5 through the same pivot shaft in groups of two.

[0244] In addition, in some embodiments, a length of each leg 6 is telescopic to provide the seat iwith more height options. Specifically, each leg 6 includes, for example, at least two telescopic legs that are sleeved in sequence and a locking mechanism for unlocking or locking relative movements of these telescopic legs. When it is necessary to adjust the height of the seat 1, the telescopic leg is unlocked, and then the length of the telescopic leg is adjusted to a desired length, finally the telescopic leg is locked again. Alternatively, each leg 6 may include, for example, two sleeve pipes sleeved in sequence. The two sleeve pipes are detachably connected, and the two heights of the seat 1 can be adjusted by detaching or not detaching the sleeve pipe.

[0245] Referring to FIGS. 24 and 26, the first sliding member 761 is, for example, annular in shape, and is sleeved on the outside of the column portion 50311 in the receiving cavity 5001. The first sliding member 761 can move in the vertical direction V along the column portion 50311, that is, the first sliding member 761 is slidably cooperated with the slideway 5031. A plurality of linking members 762 is connected between the first sliding member 761 and the plurality of legs 6. More specifically, the lower housing 502 has a plurality of first through grooves 5021 connected to the receiving cavity 5001. The first end of each linking member 762 extends through the first through grooves 5021, and then is pivotally connected to the first sliding member 761 through the pivot shaft 551. The second end of each linking member 762 is pivotally connected to each leg 6 through the pivot shaft 552 outside the receiving cavity 5001.

[0246] Referring to FIG. 27, in some embodiments, the first sliding member 761 is provided with a plurality of slots 7610 for receiving first ends of a plurality of linking members 762. A recess 7613 may be provided near each slot 7610, and adjacent slots 7610 and the recess 7613 are connected through a shaft hole (not shown in figures). Each pivot shaft 551 can be inserted into the shaft hole from the recess 7613, and the shaft hole extends into the corresponding slot 7610 to be pivotally connected to the first end of the linking member 762.

[0247] Referring to FIGS. 24 and 26, in some embodiments, a reinforcing member 623 is attached to a portion of each leg 6 close to the base 5. The reinforcing member 623 can be a sheet made of metal (such as iron, steel). The reinforcing member 623 is used to be pivotally connected to the second end of each linking member 762 through the pivot shaft 552. In addition, a cover 622 can be mounted on each leg 6, and the cover 622 covers the reinforcing member 623 therein. Each cover 622 is provided with a second through groove 6220 for each linking member 762 to extend through. The second end of each linking member 762 extends through the second through groove 6220, and then is pivotally connected to the reinforcing member 623 on each leg 6 through the pivot shaft 552. It can be understood that the size of each second through groove 6220 should not interfere with the rotation of the corresponding linking member 762. Each link 762 has a bent structure, for example.

[0248] When the bracket assembly 300 of this embodiment needs to be unfolded or folded, any leg 6 may be pushed, and the leg 6 may drive the first sliding member 761 to move relative to the column portion 50311 through the corresponding linking member 762, and thus the first sliding member 761 drives the other legs 6 to be unfolded or folded synchronously through other linking members 762.

[0249] In the bracket assembly 300 according to this embodiment, each leg 6 is connected to the first sliding member 761 through a linking member 762. The first sliding member 761 can move relative to the slideway 5031 of the base 5 to drive each leg 6 to be unfolded or folded, so that the bracket assembly 300 has a compact structure. In addition, the folding of the legs 6 may not cause the seat 1 to rise relative to the base 5, and the high chair with the bracket assembly 300 may not occupy too much longitudinal space after being folded.

[0250] Referring to FIGS. 24, 26 and 27, in some embodiments, the folding mechanism of the bracket assembly 300 may further include a stabilizing member 763 and at least one first motion conversion mechanism 766.

[0251] The stabilizing member 763 is connected to the first sliding member 761 through at least one connecting member 405 to allow the stabilizing member 763 to move in the vertical direction V along with the first sliding member 761. Furthermore, the stabilizing member 763 is rotatable relative to the first sliding member 761 about a rotation axis X-X parallel to the vertical direction V. In this embodiment, the stabilizing member 763 is, for example, annular in shape. The stabilizing member 763 is sleeved on the outside of the column portion 50311 in the receiving cavity 5001. The stabilizing member 763 is coaxial with the column portion 50311.

[0252] FIGS. 27 and 28 show an exemplary connection of the stabilizing member 763 to the first sliding member 761. The stabilizing member 763 and the first sliding member 761 are both annular in shape. A central hole 7630 of the stabilizing member 763 may be sleeved on the column portion 50311, and a central hole 7611 of the first sliding member 761 may be sleeved on the column portion 50311. The stabilizing member 763 may be provided with at least one arc-shaped hole 7631. The number of the arc-shaped holes 7631 may be, for example, but not limited to four, and the plurality of arc-shaped holes 7631 maybe arranged at even intervals around the rotation axis X-X. For example, the first sliding member 761 is provided with at least one through hole 7612, the number and position of the through hole 7612 correspond to the number and position of the arc-shaped holes 7631. At least one connecting member 405 is, for example, a bolt, and the number of connecting members 405 is consistent with the number of through holes 7612. Each connecting member 405 is inserted into the corresponding arc-shaped hole 7631 and the through hole 7612 along the vertical direction V to connect the stabilizing member 763 to the first sliding member 761. Each connecting member 405 is slidably cooperated with the corresponding arc-shaped hole. In this way, the stabilizing member 763 can not only move in the vertical direction V along with the first sliding member 761, but also rotate relative to the first sliding member 761 around the rotation axis X-X.

[0253] Of course, the connection of the stabilizing member 763 to the first sliding member 761 is not limited to the above examples. For example, in some embodiments not shown, the position of the arc-shaped hole 7631 on the stabilizing member 763 and the position of the through hole 7612 on the first sliding member 761 are interchangeable. In some other embodiments not shown, at least one connecting member 405 includes, for example, at least two engaging hooks. Each engaging hook is extended, for example, from one of the stabilizing member 763 and the first sliding member 761 in the vertical direction V, and is adapted to be engaged with another of the stabilizing member 763 and the first sliding member 761, while allowing the stabilizing member 763 to rotate relative to the first sliding member 761 about the rotation axis X-X. More specifically, in some embodiments, two or more engaging hooks are extended downward, for example, from the outer circumference of the stabilizing member 763, and a hook body of each engaging hook hooks the first sliding member 761, so that the stabilizing member 763 and the first sliding member 761 can move along the column portion 50311 synchronously. Two or more engaging hooks are arranged at even intervals around the rotation axis XX, and an end surface of the first sliding member 761 may be provided with an annular slideway that slidably cooperated with the hook body of each engaging hook.

[0254] At least one first motion conversion mechanism 766 is disposed between the stabilizing member 763 and the base 5, more specifically, between the stabilizing member 763 and the column portion 50311. The number of the first motion conversion mechanisms 766 maybe, for example, but is not limited to four. The plurality of first motion conversion mechanisms 766 may be arranged at even intervals around the rotation axis X-X, for example. When the stabilizing member 763 moves in the vertical direction V along with the first sliding member 761, each first motion conversion mechanism 766 drives the stabilizing member 763 to rotate around the rotation axis X-X relative to the first sliding member 761.

[0255] Referring to FIG. 27, an exemplary implementation of the first motion conversion mechanism 766 is shown in this embodiment. Specifically, the first motion conversion mechanism 766 may include a first driving chute 7660 and a first driving pin 7661. The first driving chute 7660 is disposed on the base 5, more specifically, for example, on the column portion 50311. The first driving pin 7661 is disposed on the stabilizing member 763 and slidably cooperated with the first driving chute 7660. For example, the stabilizing member 763 is provided with a mounting hole 7632, and the first driving pin 7661 is mounted in the mounting hole 7632. When the stabilizing member 763 moves up and down along the vertical direction with the first sliding member 761, the different inclined walls of the first driving chute 7660 abut against the first driving pin 7661, thereby pushing the stabilizing member 763 to move forward and backward around the rotation axis X-X. Of course, the implementation of the first motion conversion mechanism 766 is not limited to the above example, as long as it can push the stabilizing member 763 to rotate around the rotation axis X-X when the stabilizing member 763 moves along with the first sliding member 761. For example, in some alternative embodiments, the first driving chute 7660 may be disposed on the stabilizing member 763, and the first driving pin 7661 may be mounted on the column portion 50311 of the base 5 and slidably cooperated with the first driving chute 7660.

[0256] For the bracket assembly 300 equipped with the stabilizing member 763 and the first motion conversion mechanism 766, when the first sliding member 761 is pushed by any leg 6 to move in the vertical direction V, the stabilizing member 763 may move along with the first sliding member 761, and the stabilizing member 763 rotates around the rotation axis X-X under the action of the first motion conversion mechanism 766, so that the stabilizing member 763 is not easy to tilt and can move smoothly in the vertical direction V. The smooth movement of the stabilizing member 763 in the vertical direction V acts on the first sliding member 761 through the plurality of connecting members 405, so that the entire first sliding member 761 can also move smoothly in the vertical direction V, driving each leg 6 to be unfolded or folded simultaneously.

[0257] See FIGS. 29 and 30, a side view and a cross-sectional views of the leg folding structure. The bracket assembly 300 may further include at least one locking member 767, which is used for locking the first sliding member 761 to limit the movement of the first sliding member 761 in the vertical direction V relative to the column portion 50311, thereby maintaining the bracket assembly 300 in an adjusted state. The number of locking members 767 maybe, but is not limited to two, and the plurality of locking members 767 maybe arranged at even intervals around the rotation axis X-X, for example. Each locking member 767 may be mounted on the lower housing 502 of the base 5, for example, and each locking member 767 may move, for example, in a transverse direction H that is not parallel to the vertical direction V, so as to be engaged with or disengaged from the first sliding member 761, thereby locking or unlocking the first sliding member 761. In this embodiment, the transverse direction H may also be called a horizontal direction, and the transverse direction H is perpendicular to the vertical direction V, for example.

[0258] Referring to FIGS. 27 and 30, in some embodiments, the first sliding member 761 includes at least one locking portion 7614, and each locking portion 7614 includes one or more locking recesses 76140. In some embodiments, the number of locking members 7614 maybe but is not limited to two, and the plurality of locking members 7614 maybe arranged at even intervals around the rotation axis XX, for example. The number of locking members 767 is, for example, consistent with the number of locking portions 7614. Each locking member 767 may include one or more locking protrusions 7671. One or more locking recesses 76140 selectively cooperated with one or more locking protrusions 7671 to lock the first sliding member 761 at different positions (heights) of the column portion 50311 (that is, the slideway 5031), thereby maintaining the bracket assembly 300 in the adjusted state.

[0259] Specifically, in this embodiment, each locking portion 7614 includes one locking recess 76140. Each locking member 767 is located outside the receiving cavity 5001 and has two locking protrusions 7671, which are spaced apart in the vertical direction V. The lower housing 502 of the base 5 is provided with two holes 5027, and each locking protrusion 7671 can extend into the receiving cavity through the corresponding holes 5027. Referring to FIG. 30, when the first sliding member 761 moves to a lower position with the unfolded leg 6, the lower locking protrusion 7671 of the two locking protrusion 7671 is cooperated with the locking recess 76140, the first sliding member 761 is locked, and the bracket assembly 300 is maintained in the unfolded state. When the movement of each locking member 767 in the transverse direction H causes each locking protrusion 7671 to move out of the movement path of the first sliding member 761, the first sliding member 761 may move upward along with the folded leg 6. When the first sliding member 761 moves into place, the movement of each locking member 767 in the transverse direction causes the upper locking protrusion 7671 to be cooperated with the locking recess 76140, so that the first sliding member 761 is locked again, and the bracket assembly 300 is maintained in the folded state. It can be understood that in some alternative embodiments, each locking member 767 may include more locking protrusions 7671 spaced apart in the vertical direction V, and these locking protrusions 7671 are selectively cooperated with the locking recesses 76140 to lock the first sliding member 761 is locked at different positions of the column portion 50311, so as to stably maintain the bracket assembly 300 in any adjusted state.

[0260] In some alternative embodiments, each locking member 767 may have one locking protrusionybyi. Each locking portion 7614 may include two or more locking recesses 76140 spaced apart in the vertical direction V. According to the position change of the first sliding member 761 relative to the column portion 50311, the locking protrusion 7671 is selectively cooperated with one of the plurality of locking recesses 76140 to limit the sliding of the first sliding member 761 relative to the column portion 50311. Of course, in some alternative embodiments, each locking member 767 may have a plurality of locking protrusions 7671, and each locking protrusion76i4 may include a plurality of locking recesses 76140. As the position of the first sliding member 761 moves in the vertical direction V, the plurality of locking protrusions 7671 and the plurality of locking recesses 76140 may be selectively fitted to lock the position of the first sliding member 761.

[0261] Referring to FIGS. 27, 31 and 32, the bracket assembly 300 may further include at least one unlocking member 768 and at least one elastic member 769. In some embodiments, the number of the unlocking members 768 and the elastic members 769 is consistent with the number of the locking members 767, for example. The locking member 768 is operatively connected to the locking member 767 and is used to drive the locking member 767 to unlock the first sliding member 761. More specifically, each locking member 768 has a receiving groove 7680, for example. The locking member 767 is mounted in the receiving groove 7680, for example. The elastic member 769 is used to drive the locking member 767 to lock the first sliding member 761. In some alternative embodiments, a plurality of locking members 767 may share one unlocking member 768, and the number of elastic members 769 maybe inconsistent with the number of locking members 767.

[0262] In some embodiments, the lower housing 502 of the base 5 is provided with at least one sliding slot 5025, for example. The number of sliding slot 5025 is, for example, consistent with the number of unlocking members 768 and the sliding slot 5025 extend in the vertical direction V. Each unlocking member 768 is mounted in the corresponding sliding slot 5025 and can move along the sliding slot 5025 in the vertical direction V. A second motion conversion mechanism 7662 is provided between each unlocking member 768 and the corresponding locking member 767. The second motion conversion mechanism 7662 is used to convert the movement of each unlocking member 768 in the vertical direction V into the movement of each locking member 767 in the transverse direction H, so that each locking member 767 is allowed to lock or unlock the first sliding member 761.

[0263] FIGS. 31 and 32 show an exemplary implementation of the second motion conversion mechanism 7662. Specifically, the second motion conversion mechanism 7662 includes a second driving chute 76620 and a second driving pin 76621. The second driving chute 76620 is disposed on the unlocking member 768. The second driving pin 76621 is disposed on the locking member 767 and is slidably cooperated with the second driving chute 76620. In some embodiments, a mounting hole for mounting the second driving pin 76621 may be disposed on the locking member 767. In some embodiments, the second driving pin 76621 maybe attached to or integrally formed with the locking member 767. When the unlocking member 768 moves up and down along the sliding slot 5025, the different inclined walls of the second driving chute 76620 abut against the second driving pin 76621, thereby pushing the locking member 767 to move along the transverse direction H, so as to lock or unlock the first sliding member 761. Of course, the implementation of the second motion conversion mechanism 7662 is not limited to the above example, as long as the locking member 767 can be driven to lock or unlock the first sliding member 761 when the locking member 768 moves in the vertical direction V. For example, in some alternative embodiments, the second driving chute 76620 may be disposed on the locking member 767, and the second driving pin 76621 may be mounted on the unlocking member 768 and slidably engage the second driving chute 76620.

[0264] Referring to FIGS. 30 to 32, the connection of the unlocking member 768 to the locking member 767 is maintained by the fitting of the second driving chute 76620 with the second driving pin 76621. By reasonably setting the unlocking stroke of the unlocking member 768, it is avoided that the locking protrusion 7671 is completely exited from the corresponding hole of the lower housing 502 when the unlocking member 768 drives the locking member 767 to unlock, that is, the unlocking member 768 is prevent from being exited from the sliding slot 5025. Of course, preventing the unlocking member 768 from being exited from the sliding slot 5025 may also be implemented in many other ways, which is not described in detail here. [0265] In this embodiment, the unlocking member 768 may be provided with an outwardly protruding operating portion 7681 to facilitate the user to operate the unlocking member 768. In addition, in this embodiment, when the unlocking member 768 moves upward, the locking member 767 is driven to unlock the first sliding member 761; and when the unlocking member 768 moves downward, the locking member 767 is driven to lock the first sliding member 761. Referring to FIG. 30, the elastic member 769 is, for example, a spring, which may be arranged along the vertical direction V and clamped between the unlocking member 768 and the lower housing 502 of the base 5. The elastic member 769 exerts a downward force on the unlocking member 768, thereby driving the locking member 767 to move toward a position where the locking member 767 locks the first sliding member 761. Of course, in some alternative embodiments, it may be designed that when the unlocking member 768 moves downward, the locking member 767 is driven to unlock the first sliding member 761; and when the unlocking member 768 moves upward, the locking member 767 is driven to lock the first sliding member 761.

[0266] In some alternative embodiments, the bracket assembly 300 provided by the present application, for example, may have the following variations.

[0267] I. The base 5 is not limited to consisting of the upper housing 501, the middle housing 503 and the lower housing 502. For example, in some embodiments, the base 5 may not have the upper housing 501, so that the middle housing 503 directly faces the seat 1, and the middle housing 503 and the lower shell 502 define a receiving cavity 5001. Alternatively, in some embodiments, the base 5 may not have the lower housing 502, and the base 5 may not have the receiving cavity 5001. In this case, both the first sliding member 761 and the stabilizing member 763 may be exposed. The locking member 767, the unlocking member 768, the elastic part 769 and other components associated with the lower housing 502 may be mounted on the middle housing 503. In some alternative embodiments, the base 5 may even have only a middle housing 503.

[0268] II. The slideway 5031 is not limited to being formed by the outer peripheral wall of the cylindrical column portion 50311 extending in the vertical direction V. For example, in some embodiments, the base 5 has a cylindrical hollow sliding slot extending in the vertical direction V, and the cylindrical hollow sliding slot forms, for example, a slideway 5031. The stabilizing member 763 may be sleeved in the cylindrical hollow sliding slot, and the first sliding member 761 has, for example, a sliding portion sleeved in the cylindrical hollow sliding slot. The first motion conversion mechanism 766 is disposed between the stabilizing member 763 and a wall of the slideway 5031.

[0269] III. In some embodiments, at least one of the unlocking member 768 and the elastic member 769 may not be provided. For example, a sliding slot extending along the transverse direction H is disposed on the base 5, and the locking member 767 is, for example, a latch slidingly engaged with the sliding slot. The locking member 767 may have an operating portion for the user to operate. The user manually moves the operating portion to cause the locking member 767 to lock or unlock the first sliding member 761. In some embodiments, the elastic member 769 is, for example, directly clamped between the locking member 767 and the base 5 to drive the locking member 767 to move toward the position where the locking member 767 locks the first sliding member 761.

[0270] Third Embodiment

According to an embodiment of the present application, a high chair is provided. More specifically, the high chair is, for example, a child seat (also known as a child dining chair or chair) as an example. As shown in FIGS. 33 to 35, the child seat includes a seat assembly too, a bracket assembly (also called a supporting assembly) 200 and a seat adjustment device 400. The seat assembly too is connected to the bracket assembly 200 through the seat adjustment device 400. The bracket assembly 200 includes a base (also called a supporting base) 5 and a plurality of legs (also called support feet) 6 connected to the base 5. The base 5 is provided with an accommodation hole 5211. The seat adjustment device 400 is connected to the base 5 through the accommodation hole 5211 and is rotatable relative to the base 5. It should be understood that the seat adjustment device 400 provided by the present application is not only used in child seats, but may also be used in chairs such as growth chairs and office chairs.

[0271] In some embodiments, as shown in FIGS. 36 to 38, the seat adjustment device 400 includes a first adjustment column 431, a second adjustment column 432, a height adjustment mechanism 433, a mounting base 435, an adjustment base 436 and a rotation adjustment mechanism 437. The first adjustment column 431 is located approximately on a middle position of the bottom of the seat assembly too, and the second adjustment column 432 is located approximately on a middle position of the top of the base 5. The first adjustment column 431 is connected to the seat assembly too through the mounting base 435. The mounting base 435 includes an upper cover 4351, a lower cover 4352 and a connecting tube 4353. The upper cover 4351 is connected to the seat assembly too. The first adjustment column 431 is connected to the upper cover 4351. The lower cover 4352 and the upper cover 4351 enclose to form a first receiving cavity 4354, and at least a part of the height operating member 4337 (detailed below) is received in the first receiving cavity 4354. Specifically, the lower cover 4352 is detachably connected to the upper cover 4351, for example, through rivets or other connecting members. Referring to FIG. 37, the connecting tube 4353 is connected to the upper cover 4351. Specifically, the connecting tube 4353 and the upper cover 4351 are integrally formed. The connecting tube 4353 is arranged around the outer periphery of the first adjustment column 431. The connecting tube 4353 and the first adjustment column 431 enclose to form a second receiving cavity 4355 for partially accommodating the height adjustment mechanism 433. The second receiving cavity 4355 is connected to the first receiving cavity 4354, so that a height locking member 4331 (detailed below) and the height operating portion 4337 (detailed below) of the height adjustment mechanism 433 are driveably connected. In other embodiments, the lower cover 4352 may not be provided, and the height operating member 4337 is operatively connected to the upper cover 4351. [0272] Referring to FIGS. 37 and 38, the first adjustment column 431 has a hollow inner cavity 4311. Specifically, the first adjustment column 431 has a hollow tubular structure. The second adjustment column 432 is connected to the bracket assembly 200 and is insertably cooperated with the first adjustment column 431. In some embodiments, the first adjustment column 431 is insertably cooperated with the second adjustment column 432 in a non-rotatable manner. Specifically, an end of the second adjustment column 432 is inserted into and movable along the hollow inner cavity 4311, and another end of the second adjustment column 432 is connected to the base 5. In this embodiment, the second adjustment column 432 is a hollow tubular structure, and the second adjustment column 432 is rotatably connected to the base 5 through the adjustment base 436. Specifically, the adjustment base 436 is received in the accommodation hole 5211 and is rotatable relative to the base 5, and the second adjustment column 432 is fixedly connected to the adjustment base 436. In other embodiments, the adjustment base 436 may be received in the accommodation hole 5211 and fixed relative to the base 5, and the second adjustment column 432 is rotatably connected to the adjustment base 436. In some other embodiments not shown, the adjustment base 436 may not be provided, and the second adjustment column 432 may be fixedly or rotatably connected to the accommodation hole 5211.

[0273] Referring to FIGS. 37 and 38, in this embodiment, both left and right sides of the first adjustment column 431 are provided with a height adjustment mechanism 433. For convenience of description, the height adjustment mechanism 433 on the left side in FIG. 37 is taken as an example for description. The structure and working principle of the height adjustment mechanism 433 on the right side in FIG. 37 are roughly the same as that on the left side.

[0274] Specifically, the height adjustment mechanism 433 includes a height locking member 4331, a height driving member 4332, a fixed base 4333, a first reset member 4334 and a plurality of adjustment holes 4336 disposed on the second adjustment column 432. The fixed base 4333 is connected to the first adjustment column 431. In this embodiment, the fixed base 4333 is insertably cooperated with an end of the first adjustment column 431 away from the mounting base 435. The fixed base 4333 includes a first portion 43331 and a second portion 43332. The first adjustment column 431 is inserted into the first portion 43331. The first portion 43331 is at least partially received in the second receiving cavity 4355 to connect to the height locking member 4331. The second portion 43332 covers an end of the first adjustment column 431 away from the upper cover 4351 and abuts against the connecting tube 4353. The second portion 43332 forms a bottom wall of the second receiving cavity 4355.

[0275] Referring to FIGS. 42 and 44, at least two lugs 43337 are disposed on an outer periphery of the first portion 43331. In this embodiment, the number of lugs 43337 is four, and the four lugs 43337 are symmetrically arranged around the outer periphery of the first portion 43331. For the convenience of description, two lugs 43337 are taken as an example. The two lugs 43337 are arranged parallel to each other, and the two lugs 43337 and the second portion 43332 enclose to form a first receiving groove 43336. At least a part of the height driving member 4332 is received in and movable along the first receiving groove 43336. A first protruding column 43338 is disposed in the first receiving groove 43336. The lug 43337 of the fixed base 4333 is provided with a guide groove 43333, and an extension direction of the guide groove 43333 is perpendicular to the axial direction of the first adjustment column 431.

[0276] Referring to FIGS. 37, 38 and 40, a protrusion 4322 is disposed on the outer surface of the second adjustment column 432. Specifically, the second adjustment column 432 includes an adjustment tube 4323 and a tube plug 4321. An end of the adjustment tube 4323 is connected to the base 5, and another end of the adjustment tube 4323 is provided with the tube plug 4321. The protrusion 4322 is formed on a side of the tube plug 4321. The protrusion 4322 abuts against and slidable relative to the cavity wall of the hollow inner cavity 4311 of the first adjustment column 431. By providing the protrusion 4322, the sliding stability of the first adjustment column 431 can be ensured. Optionally, the number of protrusions 4322 may be one or at least two. In some other embodiments not shown, the protrusion 4322 may also be formed on the outer wall of the adjustment tube 4323, which is not limited in this application. Referring to FIG. 41 as well. An end of the first adjustment column 431 away from the seat assembly too is provided with a fixed base 4333. The fixed base 4333 is provided with a groove 43335. The groove 43335 is adapted to cooperate with the protrusion 4322 and allows the protrusion 4322 to extend through. Specifically, the second portion 43332 of the fixed base 4333 is provided with an insertion hole 43334 corresponding to the hollow inner cavity 4311. Referring to FIG. 41 as well. The insertion hole 43334 is connected to the hollow inner cavity 4311. A side wall of the insertion hole 43334 is provided with a groove 43335. Alternatively, the number of grooves 43335 may be one or at least two. The number, position, shape, etc. of the grooves 43335 correspond to those of the protrusions 4322. The fitting of the groove 43335 with the protrusion 4322 can play a guiding role, and can also facilitate the insertion of the second adjustment column 432 into the hollow inner cavity 4311 of the first adjustment column 431. In some other embodiments not shown, the groove 43335 may be formed on the cavity wall of the hollow inner cavity 4311 of the first adjustment column 431. In some other embodiments not shown, the protrusion 4322 may be formed on the cavity wall of the hollow inner cavity 4311, and the groove 43335 may be formed on the outer surface of the second adjustment column 432, etc., which are not limited by this application.

[0277] In some embodiments, as shown in FIGS. 37 and 38, at least a portion of the height locking member 4331 is received in the second receiving cavity 4355. Referring to FIG. 42 as well. An end of the height locking member 4331 is connected to the fixed base 4333. Specifically, an end of the height locking member 4331 is connected to the first driving pin 4335. The first driving pin 4335 is inserted into and movable alone the guide groove 43333 of the fixed base 4333. Such arrangement allows the height locking member 4331 to move along the extension direction of the guide groove 43333, that is, the height locking member 4331 moves closer to or away from the portion of the second adjustment column 432 where the adjustment hole 4336 is disposed, thereby preventing the height locking member 4331 from being deflected during movement.

[0278] Another end of the height locking member 4331 is the first engaging end 43311. The first adjustment column 431 is provided with a first through hole 4312 for the first engaging end 43311 of the height locking member 4331 to extend through. The fixed base 4333 is correspondingly provided with a second through hole 43339. Referring to FIG. 12 as well, the second through hole 43339 penetrates the first portion 43331 of the fixing base 4333 and the first protruding column 43338, and is connected to the first through hole 4312. The height locking member 4331 is movably inserted through the first through hole 4312 and the second through hole 43339, and is switchable between a first locking position (also called a height locking position) and a first unlocking position (also called a height unlocking position). When the height locking member 4331 is in the first locking position, the first engaging end 43311 of the height locking member 4331 extends through the second through hole 43339 and the first through hole 4312 to be engaged with at least one of the plurality of adjustment holes 4336. In this embodiment, the height locking member 4331 is in the shape of a pin, and the number of the first engaging end 43311 is one. The first engaging end 43311 can extend through the second through hole 43339 and the first through hole 4312 to be engaged with one of the plurality of adjustment holes 4336. When the height locking member 4331 is in the first unlocking position, the height locking member 4331 is disengaged from the adjustment hole 4336, that is, the first engaging end 43311 of the height locking member 4331 is disengaged from the adjustment hole 4336, so that the first adjustment column 431 is movable relative to the second adjustment column 432.

[0279] In the seat adjustment device 400 according to this embodiment, the height locking member 4331 moves between the first locking position and the first unlocking position, so that the first adjustment column 431 may be fixed or movable relative to the second adjustment column 432, thereby adjusting the height of the seat assembly 100 relative to the bracket assembly 200 (i.e., the base 5).

[0280] As shown in FIGS. 37 and 38, the height driving member 4332 is received in the second receiving cavity 4355. At least a portion of the height driving member 4332 is received in the first receiving groove 43336 and is movable relative to the first receiving groove 43336. Referring to FIGS. 43 and 44 together. The height driving member 4332 is provided with a first driving groove 43321. The extension direction of the first driving groove 43321 is inclined relative to the moving directions Di and D2 of the height locking member 4331. The moving directions Di and D2 of the height locking member 4331 are substantially perpendicular to the length extension direction of the second adjustment column 432, and the moving directions D3 and D4 of the height driving member 4332 are substantially parallel to the length extension direction of the second adjustment column 432. In this embodiment, the length extension direction of the second adjustment column 432 is also the axial direction of the second adjustment column 432that is parallel to the axial direction of the first adjustment column 431. The first driving pin 4335 is connected to the height locking member 4331. The first driving pin 4335 is insertably cooperated with and movable along the first driving groove 43321. In some embodiments, the moving direction of the height driving member 4 332 is substantially perpendicular to the height locking member 4331. Specifically, the first driving pin 4335 extends through the first driving groove 43321 and the guide groove 43333, so that the height locking member 4331 is drivingly connected to the height driving member 4332. In other embodiments not shown, the height locking member 4331 may be provided with the first driving groove 43321, and the first driving pin 4335 may be fixedly or detachably disposed on the height driving member 4332.

[0281] As shown in FIGS. 37 and 38, the first reset member 4334 is disposed between the height driving member 4332 and the fixed base 4333. The first reset member 4334 is adapted to bias the height driving member 4332 to move the height locking member 4331 toward the first locking position. The first restoring member 4334 may be an elastic member such as a spring or a spring leaf. In this embodiment, referring to FIG. 44, the height driving member 4332 forms a first reset member receiving groove 43322 facing the first portion 43331, and at least a part of the first protruding column 43338 extends into the first reset member receiving groove 43322. The first reset member 4334 is received in the first reset member receiving groove 43322. An end of the first reset member 4334 abuts against with a wall of the first reset member receiving groove 43322, and another end of the first reset member 4334 abuts against the first protruding column 43338. The first reset member 4334 is also received in the first receiving groove 43336. In other embodiments, two ends of the first reset member 4334 may abut against the height driving member 4332 and the bottom wall of the second receiving cavity 4355 respectively. Referring to FIG. 38, when the height locking member 4331 is operated to the first unlocking position, the first reset member 4334 is in a compressed state, and the height driving member 4332 is driven to move in the D4 direction under the elastic restoring force of the first reset member 4334., the height driving member 4332 drives the first driving pin 4335 to move in the Di direction through the first driving groove 43321, the height locking member 4331 is driven to move from the first unlocking position to the first locking position in the Di direction, so that the first engaging end 43311 extends through the first through hole 4312 and is engaged with one of the adjustment holes 4336. The arrangement of the first reset member 4334 enables the height locking member 4331 to automatically return from the first unlocking position to the first locking position.

[0282] In some embodiments, as shown in FIGS. 36 to 37, the height adjustment mechanism 433 includes a height operating member 4337, a traction member 4338, and a second reset member 4339. The height operating portion 4337 is drivingly connected to the height driving member 4332 through the traction member 4338. Specifically, an end of the traction member 4338 is received in the first receiving cavity 4354 and connected to the height operating member 4337, and another end of the traction member 4338 extends into the second receiving cavity 4355 and is connected to the height driving member 4332. [0283] As shown in FIG. 37, the height operating member 4337 is operably disposed on the mounting base 435. When the height operating member 4337 is operated, the height operating member 4337 is switchable between the first position and the second position. For example, when the height operating member 4337 moves from the first position to the second position, the height operating member 4337 drives the height locking member 4331 to switch from the first locking position to the first unlocking position through the traction member 4338. The height operating portion 4337 includes a first operating portion 43371 and a first connecting portion 43372. The first operating portion 43371 is connected to substantially the middle portion of the first connecting portion 43372. The first connecting portion 43372 is movably received in the first receiving cavity 4354- The lower cover 4352 is provided with a first through hole 4356, and the first operating portion 43371 extends out of the first receiving cavity 4354 through the first through hole 4356. The first operating portion 43371 can abut against the side wall of the first through hole 4356 to limit the movement stroke of the height operating member 4337. An end of the first connecting portion 43372 is connected to the traction member 4338, and another end of the first connecting portion 43372 is provided with a second reset member receiving groove 43373 for receiving the second reset member 4339- A groove opening of the second reset member receiving groove 43373 faces the outside of the mounting base 435 in the radial direction.

[0284] Referring to FIG. 37, the second reset member 4339 is adapted to bias the height operating member 4337 to move the height operating member 4337 toward the first position. The second reset member 4339 is received in the first receiving cavity 4354, and the two ends of the second reset member 4339 are respectively abut against the height operating member 4337 and the cavity wall of the first receiving cavity 4354. Specifically, an end of the second reset member 4339 abuts against the radially outer wall of the mounting base 435 of the first receiving cavity 4354, and another end of the second reset member 4339 is received in the second reset member receiving groove 43373 and abuts against the bottom wall of the second reset member receiving groove 43373, so that the second reset member 4339 can be prevented from deflecting during the deformation process.

[0285] Referring to FIGS. 37 and 38, when it is necessary to adjust the height of the seat assembly too, an external force is applied to the height operating member 4337 to move the height operating member 4337 from the first position to the second position. The height operating member 4337 drives the height driving member 4332 to move in the D3 direction (upward) through the traction member 4338. Through the plug-fitting of the guide groove 43333, the first driving groove 43321 and the first driving pin 4335 (see FIG. 42 and FIG. 43), the height locking member 4331 is driven to move in the D2 direction (toward the outside of the second adjustment column 432). In this way, the height locking member 4331 moves from the first locking position to the first unlocking position, that is, the first engaging end 43311 of the height locking member 4331 is disengaged from the corresponding adjustment hole 4336. In this case, the first adjustment column 431 can be moved relative to the second adjustment column 432 to adjust the height of the seat assembly 100. [0286] When the seat assembly too is adjusted to the required height, that is, when the first adjustment column 431 moves to the required height position relative to the second adjustment column 432, the first through hole 4312 is aligned with the other corresponding adjustment hole 4336. The external force applied to the height operating member 4337 is released, the height operating member 4337 moves from the second position to the first position under the elastic restoring force of the second reset member 4339, the traction member 4338 relaxes, and the external force transmitted to the height driving member 4332 through the traction member 4338 is eliminated. Referring to FIG. 37, the height driving member 4332 moves in the D4 direction (downward) under the elastic restoring force of the first reset member 4334, and through the plugfitting of the first driving pin 4335, the guide groove 43333 and the first driving groove 43321, the height locking member 4331 is driven to move in the Di direction (toward the inside of the second adjustment column 432), so that the first engaging end 43311 of the height locking member 4331 is engaged in the adjustment hole 4336 aligned with the first through hole 4312, and the first adjustment column 431 is locked relative to the second adjustment column 432. In this way, the seat assembly 100 is locked at the desired height.

[0287] In the seat adjustment device 400 in the embodiment of the present application, the first adjustment column 431 is insertably cooperated with the second adjustment column 432, and the height adjustment mechanism 433 is used to restrict or release the relative movement between the first adjustment column 431 and the second adjustment column 432, thereby realizing the height adjustment of the seat assembly 100 relative to the bracket assembly 200. The seat adjustment device 400 in the embodiment of the present application has a simple structure and is easy to operate.

[0288] In some embodiments, as shown in FIGS. 37 and 38, the seat adjustment device 400 further includes an anti-separation mechanism 438. Referring to FIG. 40 and FIG. 41, the antiseparation mechanism 438 includes an elastic finger 4381 and an engaging groove 4382 disposed on the adjustment base 436. Specifically, the adjustment base 436 has a first accommodation groove 4361, and the engaging groove 4382 is disposed on a side wall of the first accommodation groove 4361. The extension direction of the engaging groove 4382 is substantially parallel to the extension direction of the second adjustment column 432. The lower end of the second adjustment column 432 is fixed to the bottom wall of the first accommodation groove 4361. In other embodiments, the engaging groove 4382 can be disposed on the base 5 of the bracket assembly 200. For example, when the adjustment base 436 is not provided, the engaging groove 4382 can be disposed on the side wall of the accommodation hole 5211 of the base 5. Referring to FIGS. 38 and 41, the elastic finger 4381 has a hook portion 43811, and the elastic finger 4381 is disposed on the connecting tube 4353. The hook portion 43811 is movable along the engaging groove 4382 and can be engaged with the end of the engaging groove 4382. When the first adjustment column 431 moves in the D3 direction relative to the second adjustment column 432, the anti-separation mechanism 438 can prevent the first adjustment column 431 from being disengaged from the end of the second adjustment column 432 [0289] The connecting tube 4353 of the mounting base 435 is inserted into the first accommodation groove 4361 of the adjustment base 436. In this embodiment, the connecting tube 4353 and the first accommodation groove 4361 are both non-circular shapes, and include tangential walls (not numbered in figures) that abut each other, so that the mounting base 4 35 and the adjustment base 436 cannot rotate relative to each other.

[0290] In some embodiments, as shown in FIGS. 45 to 47, the rotation adjustment mechanism 437 includes a rotation locking member 4371, a rotation operating portion 4372, a rotation reset member 4373 and a plurality of insertable slots 4374 disposed on the base 5 of the bracket assembly 200. The rotation locking member 4371 is movably connected to the adjustment base 436, so that the rotation locking member 4371 is switchable between a second locking position (also called a rotation locking position) and a second unlocking position (also called ta rotation unlocking position). An end of the rotation locking member 4371 is a second engaging end 43711. A side of the adjustment base 436 away from the second adjustment column 432 is provided with a second accommodation groove 4362, and an end of the rotation locking member 4371 away from the second engaging end 43711 is received in the second accommodation groove 4362. Referring to FIG. 48 as well, the adjustment base 436 is provided with a second through hole 4363 for the rotation locking member 4371 to extend through. The second through hole 4363 penetrates the side walls of the first accommodation groove 4361 and the second accommodation groove 4362. The rotation locking member 4371 is movably inserted through the second through hole 4363. When the rotation locking member 4371 is in the second locking position, that is, when the rotation adjustment mechanism 437 is in the locking state, the second engaging end 43711 of the rotation locking member 4371 extends through the second through hole 4363 and is engaged with one of the plurality of insertable slots 4374, so that the adjustment base 436 is fixed relative to the base 5. When the rotation locking member 4371 is in the second unlocking position, that is, when the rotation adjustment mechanism 437 is in the unlocking state, the second engaging end 43711 of the driving locking member 4371 exits from the corresponding slot 4374, so that the adjustment base 436 is rotatable relative to the base 5. In this embodiment, the number of the rotation locking members 4371 is two, and the two rotation locking members 4371 are symmetrically arranged relative to the pivot axis R-R of the adjustment base 436, so that the seat assembly 100 can be more stably locked in desired orientation. In other embodiments not shown, the number of rotation locking members 4371 is one or more than two, which is not limited by this application.

[0291] Referring FIGS. 46 and 47, the number of the insertable slots 4374 is at least twice the number of the rotation locking members 4371. In this embodiment, the number of insertable slots 4374 is four. The four insertable slots 4374 are evenly arranged in the circumferential direction relative to the pivot axis R-R of the adjustment base 436. The angle between two adjacent insertable slots 4374 is approximately 90°, so that the adjustment base 436 is rotatable relative to the base 5 and can be locked at 90°, 180°, 270° and 360° respectively, that is, the seat assembly too is rotatable relative to the base 5 and can be locked at 90°, 180°, 270° and 360° respectively. By adjusting the number of insertable slots 4374 and the angle between two adjacent insertable slots 4374, the seat assembly too is rotatable relative to the base 5 and can be locked in different orientations. In other embodiments not shown, the number of insertable slots 4374 may be six, and the angle between two adjacent insertable slots 4374 is approximately 6o°. The number of insertable slots 4374 is not limited in this application. Each rotation locking member 4371 is provided with a first driving surface 43712. [0292] In some embodiments, as shown in FIGS. 46 and 47, the rotation operating member 4372 is operably disposed on the base 5. The rotation operating member 4372 is movably connected to the adjustment base 436. The adjustment base 436 is received in the accommodation hole 5211 and is rotatable relative to the base 5. Specifically, the adjustment base 436 is provided with a connecting hole 4364, and the connecting hole 4364 penetrates the bottom wall of the second accommodation groove 4362. Referring to FIG. 49 as well, the rotation operating member 4372 is provided with a connecting column 43723. The connecting column 43723 is insertably cooperated with the connecting hole 4364. Specifically, the number of connecting columns is two, and the number of connecting holes 4364 corresponds to the number of connecting columns 43723. In other embodiments, the rotation operating member 4372 may be movably connected to the second adjustment column 432.

[0293] Referring to FIG. 46, the rotation operating member 4372 is provided with a second driving surface 43721. Specifically, Referring to FIG. 49 as well, the rotation operating member 4372 includes an insertion portion 43722, and a surface of the insertion portion 43722 forms a second driving surface 43721. The number of insertion portions 43722 corresponds to the number of rotation locking members 4371. In this embodiment, the number of insertion portions 43722 is two. The two insertion portions 43722 and the two connecting columns 43723 are spaced apart. In this embodiment, the two insertion portions 43722 are arranged oppositely, and the two connecting columns 43723 are also arranged oppositely. The angle between a virtual line connecting the two insertion portions 43722 and a virtual line connecting the two connecting columns 43723 is approximately 90°. Correspondingly, referring to FIG. 47 as well, each rotation locking member 4371 is provided with an insertion slot 43713, and the side wall of the insertion slot 43713 forms a first driving surface 43712. The two insertion portions 43722 are insertably fitted into the corresponding insertion slots 43713 of the two rotation locking members 4371 respectively, and the second driving surface 43721 abuts against the first driving surface 43712. In some embodiments, at least one of the first driving surface 43712 and the second driving surface 43721 is inclined relative to the extension direction of the rotation locking member 4371. In this embodiment, the moving directions D5 and D6 of the rotation locking member 4371 are substantially perpendicular to the extension direction of the second adjustment column 432 and are substantially perpendicular to the moving directions Di and D2 of the height locking member 4331. The moving directions D7 and D8 of the rotation operating member 4372 are substantially parallel to the extension direction of the second adjustment column 432. [0294] As shown in FIGS. 46 and 47, the rotation reset member 4373 is received in the second receiving groove 4362. The rotation reset member 4373 is adapted to bias the two rotation locking members 4371 to move toward the second locking position. The rotation reset member 4373 includes elastic members such as springs and elastic leaves. In this embodiment, the number of the rotation reset member 4373 is one. The rotation reset member 4373 is connected between the two rotation locking members 4371, and the two ends of the adjustment base 436 respectively abut against the two rotation locking members 4371. Specifically, a third reset member receiving groove 43714 is provided at an end of each rotation locking member 4371 away from the second engaging end 43711. Both ends of the rotation reset member 4373 are received in the third reset member receiving grooves 43714 of the two rotation locking members 4371. In other embodiments, a plurality of the rotation reset members 4373 may be provided. For example, two rotation reset members 4373 are provided corresponding to the rotation locking members 4371. An end of each rotation reset member 4373 abuts against the corresponding rotation locking member 4371, and another end of each rotation reset member 4373abuts against the side wall of the second accommodation groove 4362.

[0295] When the seat assembly 100 needs to be adjusted, an external force is applied to the rotation operating member 4372 to move the rotation operating member 4372 in the D7 direction. Through the driving fitting of the first driving surface 43712 and the second driving surface 43721, the two rotation locking members 4371 move toward each other, so that the second engaging ends 43711 of the two rotation locking members 4371 are disengaged from the insertable slots 4374 respectively, thereby making the adjustment base 436 rotatable relative to the base 5, that is, making the seat assembly 100 rotatable relative to the base 5.

[0296] When the seat assembly 100 is rotated at a certain angle (for example, 90°) to the desired orientation, the external force exerted on the rotation operating member 4372 is removed, under the elastic restoring force of the rotation reset member 4373, the two rotation locking members 4371 move in the opposite directions to the second locking position, causing the second engaging end 43711 of each rotation locking member 4371 to be engaged with the corresponding slot 4374, thereby limiting the relative rotation between the adjustment base 436 and the base 5, that is, locking the seat assembly 100 in the desired position.

[0297] In the seat adjustment device 400 according to the embodiment of the present application, a rotation adjustment mechanism 437 is provided and used to rotate the seat assembly 100 relative to the bracket assembly 200 and lock the seat assembly looin the required orientation, so that the orientation adjustment of the seat assembly 100 can be easily realized. As a result, both height adjustment and orientation adjustment of the child seat can be realized, which can better meet the use needs of different children in different application scenarios.

[0298] In some embodiments, as shown in FIGS. 50 to 53, the seat assembly 100 may also be detachably connected to the mounting base 435 through a seat detachment mechanism 500. As shown in FIG. 40, the seat assembly too may include a seat 1 and a tray 12. The seat 1 includes a seat portion 111, a backrest portion 112 and two side portions 113 respectively connected to two sides of the seat portion 111. As shown in FIGS. 52 to 54, the seat detachment mechanism 500 includes a detachment locking member 541, a detachment unlocking member 542, a detachment reset member 543, an engaging hole 544 disposed on the mounting base 435, and an engaging recess 545 disposed on the mounting base 435. Referring to FIG. 52, the mounting base 435 is provided with a connecting groove 4358. The engaging hole 544 is disposed on the side wall of the connecting groove 4358 and connected to the connecting groove 4358. The detachment locking member 541 is inserted into the connecting groove 4358 and movable in a direction parallel to the bottom wall of the connecting groove 4358, so that the detachment locking member 541 is movable between the third position and the fourth position.

[0299] As shown in FIGS. 51 and 52, the detachment locking member 541 is disposed on the bottom surface of the seat portion 111 of the seat 1. The detachment locking member 541 includes a hook portion 5411 and a base body 5412 that are connected to each other. An end of the base body 5412 is connected to the bottom surface of the seat portion 111, and another end of the base body 5412 is connected to the hook portion 5411. In this embodiment, the disassembly locking member 541 is an integrally formed structure. When the detachment locking member 541 is in the third position, the hook portion 5411 is engaged with the engaging hole 544 to fix the seat 1 relative to the mounting base 435- When the detachment locking member 541 is in the fourth position, the hook portion 5411 is disengaged from the engaging hole 544 so that the seat 1 can be separated from the mounting base 435- The number of the detachment locking members 541 is at least two, and the number of the engaging holes 544 corresponds to the number of the detachment locking members 541. At least two disassembly locking members 541 are evenly arranged on a side of the seat portion 111 facing the mounting base 435, so that the seat assembly too can be more stably fixed on the mounting base 435. The extension directions of the hook portions 5411 of the plurality of detachment locking members

541 are the same or parallel to each other. The shapes and sizes of the plurality of hook portions 5411 can be the same or different, as long as each hook portion 5411 can be engaged with or disengaged from the corresponding engaging hole 544 when the seat assembly too moves. However, in this embodiment, the number of detachment locking members 541 is four, and the number of engaging holes 544 is correspondingly four. Specifically, the mounting base 435 has a substantially rectangular top surface, and the four engaging holes 544 are respectively located near the four vertex corners of the top surface of the mounting base 435. In this embodiment, the hook portion 5411 is configured to extend backward from the base body 5412 of the detachment locking member 541. In other embodiments, the hook portion 5411 can also be configured to extend forward from the base body 5412 of the detachment locking member 541, which is not limited hereto.

[0300] In some embodiments, as shown in FIGS. 53 and 54, the detachment unlocking member

542 is operably disposed on the seat assembly too, the detachment unlocking member 542 has an engaging protrusion 5421, and the detachment unlocking member 542 is switchable between the sixth unlocking position (also called the detachment unlocking position) and the sixth locking position (also called the detachment locking position). When the detachment unlocking member 542 is in the sixth locking position, the engaging protrusion 5421 can be engaged with the engaging recess 545 to restrict the detachment locking member 541 in the third position. When the detachment locking member 542 is in the unlocking position, the engaging protrusion 5421 is disengaged from the engaging recess 545, so that the detachment unlocking member 541 is in the fourth position. In this embodiment, the detachment locking member 542 is disposed on the front side of the seat portion 111 of the seat 1. In other embodiments, the detachment locking member 542 can also be disposed on the rear, left, or right side of the seat portion 111 of the seat 1. The present application is not limited to this. The seat assembly 100 is provided with a receiving hole 1014. Specifically, the receiving hole 1014 penetrates the seat portion 111 of the seat 1. The engaging protrusion 5421 of the detachment unlocking member 542 can extend through the receiving hole 1014 and be engaged with the engaging recess 545. An operating recess 5422 is disposed on an end of the detachment unlocking member 542 away from the engaging protrusion 5421 to facilitate the operation of the detachment unlocking member 542, the operating recess 5422 at least partially extends out of the receiving hole 1014.

[0301] In this embodiment, as shown in FIGS. 45 and 53, the seat assembly 100 further includes a stopper 1113. The stopper 1113 is generally in a T-shaped structure and includes a stopping portion 1031 and a supporting portion 1032 that are connected to each other. An end of the stopping portion 1031 is fixed to approximately the middle of the front edge of the seat portion 111, and another end of the stopping portion 1031 is connected to approximately the middle of the supporting portion 1032. The supporting portion 1032 abuts against and is supported below the tray 12. In this way, when the infant sits on the seat 1, the infant's legs extend out from two sides of the stopping portion 1031, and the stopping portion 1031 stops the infant's crotch to prevent the infant from sliding out of the seat 1. The front side of the stopping portion 1031 is provided with a mounting groove 10311 connected to the receiving hole 1014. At least the portion of the detachment unlocking member 542 provided with the operating recess 5422 is located in the mounting groove 10311 for operation. In other embodiments, the operating recess 5422 may not be provided, or a pull ring or the like may be disposed on the end of the detachment unlocking member 542 away from the engaging protrusion to facilitate the operation of the detachment unlocking member 542.

[0302] As shown in FIGS. 53 and 54, the detachment reset member 543 is disposed between the seat assembly 100 and the detachment unlocking member 542. The detachment reset member 543 is adapted to bias the detachment unlocking member 542 to move the detachment unlocking member 542 to the sixth locking position. The seat assembly 100 is provided with a second receiving groove 1015. The detachment unlocking member 542 also has an abutting portion 5423. At least a part of the abutting portion 5423 is received in the second receiving groove 1015 to prevent the detachment reset member 543 from deflecting. The detachment reset member 543 is received in the second receiving groove 1015 and abuts against the abutting portion 5423. In this embodiment, the abutting portion 5423 is provided with a second protruding column 5424 extending in a direction away from the engaging protrusion 5421. The detachment reset member 543 is a compression spring. An end of the detachment reset member 543 is sleeved on the second protruding column 5424, and another end of the detachment reset member 543 abuts against the groove wall of the second receiving groove 1015, thereby further reducing the deflection of the detachment reset member 543 under the action of external force.

[0303] Referring to FIGS. 52 and 54, in this embodiment, when the seat assembly too needs to be detached, the detachment unlocking member 543 is pulled to move from the sixth locking position to the sixth unlocking position, so that the detachment locking member 541 is movable relative to the mounting base 435. At this time, the detachment unlocking member 542 is maintained in the detachment unlocking position, and an external force is applied to the seat assembly too in the direction D9, so that the four detachment locking members 541 move from the third position to the fourth position in the direction of D9 at the same time. Each hook portion 5411 exits the engaging hole 544 along the connecting groove 4358 to disengage each hook portion 5411 from the corresponding engaging hole 544, thereby making the seat assembly too detachable relative to the mounting base 435. When the seat assembly too is separated from the mounting base 435 and the external force is removed, the detachment unlocking member 542 automatically returns from the sixth unlocking position to the sixth locking position under the elastic restoring force of the detachment reset member 543.

[0304] When it is necessary to mount the seat assembly too, each detachment locking member

541 is inserted into the corresponding connecting groove 4358 and each hook portion 5411 is aligned with the corresponding engaging hole 544, and at the same time, under the action of external force, for example, the engaging protrusion is pressed by the base 5, and the detachment unlocking member

542 moves from the sixth locking position to the sixth unlocking position. The detachment locking member 541 is maintained in the sixth unlocking position, and the seat assembly too is pushed along the Dio direction, so that the detachment locking member 541 moves to the sixth locking position along the Dio direction. At this time, the engaging protrusion 5421 of the detachment unlocking member 542 is aligned with the engaging recess 545, and the engaging protrusion 5421 is no longer subject to the pressing force of the base 5. The detachment unlocking member 542 moves to the sixth locking position under the elastic restoring force of the detachment reset member 543, thereby achieving a fixed connection of the seat assembly 100 to the mounting base 435.

[0305] In some embodiments, as shown in FIGS. 55 and 56, the tray 12 is connected to the seat 1 through the tray adjustment mechanism 12A. Specifically, the tray 12 is detachably connected to two side portions 113 of the seat 1 and is movable relative to the two side portions 113. The upper edges of the two side portions 113 of the seat 1 protrude outward to form armrest portions 115. In other embodiments not shown, the tray 12 may be connected to only one of the two side portions 113 of the seat i. Alternatively, the tray 12 is connected to the seat 1 through other components, such as a connecting seat fixed on the side portion 113 of the seat 1. For convenience of description, the following takes the connection between one of the two side portions 113 of the seat 1 and the tray 12 as an example for description.

[0306] As shown in FIGS. 56 to 58, the tray adjustment mechanism 12A includes a tray unlocking member 1251, an adjustment reset member 1252 and a plurality of positioning slots 1253 disposed on the side portions 113 of the seat 1. A plurality of positioning slots 1253 are located below the armrest portion 115. A side of the tray 12 that is capable of loading (for example, placing tableware, etc., thereon) is a front side 121 (see FIG. 55), and a side away from the front side 121 is the back side 122. The tray 12 is provided with a connecting plate 123 to guide the tray 12 to move along the extension direction of the connecting plate 123. The connecting plate 123 is provided with a hole 124 for the tray unlocking member 1251 to extend through. The tray 12 is further provided with a limiting portion 125, and the limiting portion 125 is disposed on an end of the connecting plate 123. The limiting portion 125 can abut against the side portion 113 of the seat 1 to limit the movement stroke of the tray 12. In this embodiment, the connecting plate 123 and the limiting portion 125 are both disposed on the back side 122 of the tray 12. The connecting plate 123 and the limiting part 125 are both provided with reinforcing ribs 126 to respectively increase their anti-deformation strength.

[0307] Referring to FIG. 57, the tray unlocking member 1251 has an engaging portion 12511 and a second operating portion 12512. The second operating portion 12512 protrudes from the engaging portion 12511 and extends away from the back side 122. The tray unlocking member 1251 is movably disposed on the tray 12. Specifically, the tray unlocking member 1251 is movably inserted into the hole 124. The second operating portion 12512 can abut against an side of the connecting plate 123 to limit the movement stroke of the tray unlocking member 1251. Referring to FIGS. 56 and 57, the tray unlocking member 1251 is provided with an elongated groove 1513, the tray 12 is provided with a connecting pin 127, and the connecting pin 127 is insertably cooperated with the elongated groove 1513. The connecting pin 127 is movable along the elongated groove 1513 and can abut against the end of the elongated groove 1513 to limit the movement stroke of the tray unlocking member 1251. In other embodiments, the tray 12 may be provided with an elongated groove 1513, and the tray unlocking member 1251 may be provided with a connecting pin 127, and the connecting pin 127 is insertably cooperated with the elongated groove 1513.

[0308] As shown in FIGS. 56 and 57, the adjustment reset member 1252 is disposed between the tray unlocking member 1251 and the tray 12. The adjustment reset member 1252 is adapted to bias the tray unlocking member 1251, so that the tray unlocking member 1251 moves to the seventh locking position (also called the tray locking position). Specifically, the adjustment reset member 1252 is received in the elongated groove 1513. An end of the adjustment reset member 1252 abuts against the end of the elongated groove 1513, and another end of the adjustment reset member 1252 abuts against the connecting pin 127. The tray unlocking member 1251 has a seventh locking position and a seventh unlocking position (which may also be called a tray unlocking position). When the tray unlocking member 1251 is in the seventh locking position, the engaging portion 12511 is engaged with at least one of the plurality of positioning slots 1253 to fix the tray 12 on the seat 1. Specifically, the engaging portion 12511 extends through the hole 124 and is engaged with one of the plurality of positioning slots 1253. At this time, the engaging portion 12511 and the second operating portion 12512 are located on the two sides of the connecting plate 123 respectively. After the tray 12 is mounted, the connecting plate 123 is located below the armrest 115 and engaged with the armrest 115 to further position the tray 12 in the up and down direction and increase the connection strength of the tray 12 in this direction. When the tray unlocking member 1251 is in the seventh unlocking position, the engaging portion 12511 is disengaged from at least one of the plurality of positioning slots 1253, so that the tray 12 can be separated from the seat 1 or is movable relative to the seat 1. Specifically, the engaging portion 12511 exits from the positioning slot 1253, so that the tray 12 can be separated from the seat 1 and is movable along the connecting plate 123. In this embodiment, the connecting plate 123 extends substantially along a front-back direction of the child seat. The moving direction of the tray 12 is substantially the front-back direction. The moving direction of the tray unlocking member 1251 is substantially perpendicular to the extension direction of the connecting plate 123, that is, the tray unlocking member 1251 can move substantially along a left-right direction of the child seat. It should be understood that the front in this application is the direction that a child riding in a child seat is facing, the rear in this application is the direction that a child riding in a child seat is facing away from, and the left-right direction in this application corresponds to the left-right direction of the child riding in the child seat.

[0309] When it is necessary to adjust or detach the tray 12, the tray unlocking members 1251 on both sides can be pushed simultaneously to move from the seventh locking position to the seventh unlocking position. The engaging portion 12511 of the tray unlocking member 1251 exits from the positioning slot 1253. At this time, the tray 12 can be moved along the extension direction of the connecting plate 123, or the tray 12 can be detached from the seat 1. When the tray 12 moves to a suitable position, one of the plurality of positioning slots 1253 is aligned with the engaging portion 12511. At this time, the external force is removed, and the tray unlocking member 1251 moves from the seventh unlocking position to the seventh locking position under the elastic restoring force of the adjustment reset member 1252, so that the engaging portion 12511 of the tray unlocking member 1251 is engaged with the corresponding positioning slot 1253, and the position adjustment of the tray 12 is realized.

[0310] The structure and connection relationship between the base 5 and the legs 6 in the third embodiment can be referred to the descriptions for the second embodiment above. That is, the third embodiment includes the bracket assembly 300 described in the second embodiment.

[0311] More specifically, the base 5 may include the upper housing 501, the middle housing 503 and the lower housing 502 described in the second embodiment, and each leg 6 may be connected to the first sliding member 761 by the linking member 762, and the first sliding member 761 slides in the vertical direction along the slideway 5031 in the base 5. The first sliding member 761 is connected to the stabilizing member 763. The accommodation hole 5211 in the third embodiment corresponds to the bottom central hole of the lower housing 502 in the second embodiment. The adjustment base 436 in the third embodiment can enter the central hole 5030 of the middle housing 503 via the central hole 5010 of the upper housing 501 in the second embodiment. The adjustment base 436 can rotate relative to the base 5 about the axis R-R. In addition, the bottom turntable 100a of the seat 1 in the second embodiment may correspond to the mounting base 435 in the third embodiment. The seat 1 in the second embodiment can be relatively rotatably connected to the base 5 by the seat adjustment device 400.

[0312] Fourth Embodiment

According to an embodiment of the present invention, a child seat (also known as a child chair, a high chair, or a chair) is provided. The child seat has multiple use modes to suit the usage needs of different groups of people, and has a simple structure and is easy to manufacture.

[0313] As shown in FIGS. 59 and 61, the child seat includes a chair body 2000 and a seat assembly too. The seat assembly too is detachably connected to the chair body 2000. The seat assembly too includes a seat (also called a seat body) 1, a stopper 1113 and a tray 12. As shown in FIG. 63, the seat 1 includes a seat portion 111, a backrest portion (also called a back portion) 112 connected to the seat portion 111, and two side portions 113 connected to the seat portion 111 and the backrest portion 112 respectively. The seat portion 111, the backrest portion 112 and the two side portions 113 jointly define a seating space of the seat assembly too. Referring to FIG. 68 as well, the stopper 1113 is generally in a T-shaped structure and includes a stopping portion 1131 and a supporting portion 1132 that are connected to each other. An end of the stopping portion 1131 is connected to substantially the middle portion of the supporting portion 1132. The stopping portion 1131 may also be integrally formed with the supporting portion 1132. The supporting portion 1132 is connected to the bottom of the tray 12. In this way, when a child rides on the seat assembly too, the child's legs extend out from the two sides of the stopping portion 1131, and the stopping portion 1131 stops the child's crotch to restrict the child within the seating space and prevent the child from sliding off the seat assembly too. The tray 12 is located above the supporting portion 1132 of the stopper 1113 to facilitate children's meals. The tray 12 is detachably connected to the two side portions 113 and can move relative to the two side portions 113, so that the seat assembly too can be adapted to children with different body sizes.

[0314] When the seat assembly too is mounted on the chair body 2000, as shown in FIG. 59, the child seat is in a first use mode, that is, the high dining chair mode. This mode is suitable for infants aged about six months to three years old to dine at the same table with adults. Infants can sit in the seating space without slipping off the high dining chair easily. When the seat assembly too is detached from the chair body 2000, as shown in FIG. 60, the child seat is in a second use mode, that is, the adult chair mode, which is suitable for use by children or adults over the age of approximately 12 years. The child seat in this mode is not limited to being used as a dining chair, but can also be used in various situations such as learning or games.

[0315] Specifically, as shown in FIGS. 59 and 60, the chair body 2000 includes a seat plate 822, a bracket assembly (also called a foot assembly) 200 connected to the seat plate 822, and a backrest 825 connected to the seat plate 822. The bracket assembly 200 includes a plurality of legs (also referred to as feet) 6. Each leg 6 includes a first leg 601 and a second leg 602. An end of the first leg 601 is rotatably connected to the seat plate 822, and another end of the first leg 601 is detachably connected to the second leg 602. As shown in FIG. 61, when the seat assembly too is mounted on the chair body 2000 and the second leg 602 is detached from the first leg 601, the child seat is in a third use mode, that is, the small dining chair mode. This mode is suitable for infants aged about six months to three years old for mealtime use. Compared with the first use mode, the child seat in this mode has less height and takes up less space, which makes it easier for infants to get in and out of the child seat independently, and also makes it easy to be fixed on an ordinary dining chair. As shown in FIG. 62, when the seat assembly too is detached from the chair body 2000 and the second leg 602 is also detached from the first leg 601, the child seat is in a fourth use mode, that is, the child seat mode. This mode is suitable for children aged approximately 3 to 12 years old. The child seat in this mode is not limited to being used as a dining chair, but can also be used in various occasions such as learning or games. The child seat in this embodiment has multiple use modes, which meets the use requirements in different scenarios and improves the use efficiency of the child seat.

[0316] Of course, in other embodiments, when the user only needs to use the second use mode and the fourth use mode, the child seat may only include the chair body 2000. Alternatively, when the user only needs to use the first use mode and the third use mode, the child seat may include the seat assembly too and the chair body 2000, and in each leg 6 of the chair body 2000, the first leg 601 and the second leg 602 are connected in a non-detachable manner, or each leg 6 is an integrally formed structure. Alternatively, when the user only needs to use the third use mode and the fourth use mode, the child seat may include the seat assembly too and the chair body 2000, and each leg 6 of the chair body 2000 only includes the first leg 601. In short, child seats may have different structures according to the needs of user.

[0317] In some embodiments, as shown in FIGS. 63 to 65, the chair body 2000 is detachably connected to the seat assembly too through a seat detachment mechanism 800. The seat detachment mechanism 800 includes a first connecting member 831 and a second connecting member 832. A longitudinal direction Qi is a front-back direction of the high chair under normal use, a transverse direction Q2 is a left-right direction of the high chair under normal use, and a vertical direction V is a height direction of the high chair under normal use.

[0318] Referring to FIG. 63, the first connecting member 831 is rotatably disposed on the seat assembly too and switchable between a fifth locking position (also called a detachment locking position) and a fifth unlocking position (also called a detachment unlocking position). Specifically, the first connecting member 831 is disposed on the backrest portion 112 of the seat assembly too. The backrest 825 is provided with a connecting hole 8251. The side of the backrest 825 facing forward is a front side 8252, and the side of the backrest 825 facing rearward is a back side 8253. When the first connecting member 831 is in the fifth unlocking position, the first connecting member 831 can move in the longitudinal direction N (see FIG. 67) along with the seat assembly too, that is, the first connecting member 831 can move from the front side 8252 of the backrest 825, through the connecting hole 8251, to the back side 8253 of the backrest 825, or the first connecting member 831 may also exit the connecting hole 8251 from the back side 8253 of the backrest 825 and reach the front side 8252 of the backrest 825. At this time, the seat assembly too is detachable from the chair body 2000. When the seat assembly too is mounted to the chair body 2000, and when the first connecting member 831 is rotated at a specific angle to cause the first connecting member 831 being in the fifth locking position, the backrest portion 112 of the seat assembly too and the first connecting member 831 are respectively located at the front and back sides of the backrest 825. The first connecting member 831 is located at the back side 8253 of the backrest 825, and the first connecting member 831 can abut against the back side 8253 of the backrest 825.At this time, the backrest 825 is clamped between the first connecting member 831 and the backrest portion 112 of the seat assembly too, the backrest portion 112 restricts the seat assembly too from moving backward relative to the backrest 825, the first connecting member 831 in the fifth locking position restricts the seat assembly too from moving forward relative to the backrest 825, so that the seat assembly too is fixed relative to the chair body 2000.

[0319] As shown in FIGS. 63 to 65, the backrest portion 112 of the seat assembly too is provided with a connecting protrusion 104 that can be insertably cooperated with the connecting hole 8251. The first connecting member 831 is rotatably connected to the connecting protrusion 104. At least a part of the outer contour of the connecting protrusion 104 abuts against the side wall of the connecting hole 8251 to prevent the connecting protrusion 104 from swinging or rocking in the first connecting hole 8251. In this embodiment, the outer contour shape of the connecting protrusion 104 is the same as the shape of the connecting hole 8251, and the cross-sectional area of the connecting protrusion 104 on a certain plane is equal to or slightly less than the cross-sectional area of the connecting hole 8251 on this plane. When the connecting protrusion 104 is fully inserted into the connecting hole 8251, the end surface of the connecting protrusion 104 slightly protrudes from the connecting hole 8251 or is flush with the end of the connecting hole 8251. As a result, the stability of the connection between the seat assembly too and the chair body 2000 is improved, and it prevents the seat assembly too from shaking or swinging relative to the chair body 2000 when the seat assembly too is fixed on the chair body 2000. In this embodiment, the number of the connecting protrusions 104, the first connecting portions 831 and the connecting holes 8251 is two, so that the connection between the seat assembly too and the chair body 2000 is more stable. In other embodiments, the number of the connecting protrusion 104, the first connecting member 831 and the connecting hole 8251 may be one or more than two.

[0320] Referring to FIGS. 64 to 66, the back side 8253 of the backrest 825 is provided with a positioning protrusion 8254, and the first connecting member 831 is correspondingly provided with a positioning recess 8311. The positioning recess 8311 is disposed on a side of the first connecting member 831 facing the back side 8253 of the backrest 825. When the first connecting member 831 is in the fifth locking position, the positioning protrusion 8254 is engaged with the positioning recess 8311, thereby limiting further rotation of the first connecting member 831 and preventing the first connecting member 831 from being accidentally rotated to the fifth unlocking position. The first connecting member 831 is made of a material with a certain amount of elastic deformation, such as a plastic material. In this way, when being operated, the first connecting member 831 can be deformed to pass over the positioning protrusion 8254 and rotate between the fifth locking position and the fifth unlocking position. In other embodiments, the back side 8253 of the backrest 825 may also be provided with a positioning recess 8311, and the first connecting member 831 may be provided with a positioning protrusion 8254 accordingly, which is not limited hereto. Referring to FIGS. 64 and 65, the back side 8253 of the backrest 825 is provided with a recess 8255. When the first connecting member 831 is in the fifth locking position, the first connecting member 831 extends through the connecting hole 8251 and abuts against the bottom wall of the recess 8255. The bottom wall of the recess 8255 is flat. When the backrest 825 has a certain curvature, the bottom wall of the recess 8255 can provide a relatively flat rotation space for the first connecting member 831, thereby facilitating the setting of the positioning protrusion 8254 and the positioning recess 8311, and the operating of users. The positioning protrusion 8254 is disposed on the bottom wall of the recess 8255. In this embodiment, two first connecting members 831 are provided, and the two first connecting members 831 are symmetrically arranged on the backrest 825 of the seat assembly too in the left-right direction. In other embodiments, the number of first connecting members 831 may be one or more than two. The number of first connecting members 831 is not limited hereto.

[0321] As shown in FIGS. 63 and 67, the second connecting member 832 is disposed on the seat assembly too. Specifically, the second connecting member 832 is provided at the bottom of the seat assembly too. In some embodiments, the second connecting member 832 is connected to or integrally formed on the lower surface of the seat portion 111 of the seat assembly too. In this embodiment, the seat detachment mechanism 800 includes two second connecting portions 832, and the two second connecting portions 832 are disposed on seat portion 111 near the front side. The second connecting member 832 is provided with a connecting groove 8321, and the second connecting member 832 is configured to be engaged with the seat plate 822 through the connecting groove 8321. Specifically, the front edge of the seat plate 822 is engaged with the connecting groove 8321. Through the connection of the second connecting member 832 to the seat plate 822, the connection between the seat assembly too and the chair body 2000 is more stable. [0322] When it is necessary to mount the seat assembly too to the chair body 2000, the first connecting member 831 is rotated to the fifth unlocking position, the connecting groove 8321 of the second connecting member 832 is engaged with the front side of the seat plate 822, and the first connecting member 831 completely extends through the connecting hole 8251 (see FIG. 6). At this time, the first connecting member 831 is rotated to the fifth locking position, the first connecting member 831 abuts against the bottom wall of the recess 8255, so that the seat assembly too is fixed on the chair body 2000. The positioning recess 8311 of the first connecting member 831 is engaged and positioned with the positioning protrusion 8254 of the backrest 825, so that the first connecting member 831 is fixed in the fifth locking position. When the seat assembly too needs to be detached from the chair body 2000, an external force can be applied to the first connecting member 831 to rotate the first connecting member 831. At the same time, the positioning recess 8311 is separated from the positioning protrusion 8254, and the first connecting member 831 is further rotated to the fifth unlocking position. At this time, the seat assembly too can be moved so that the first connecting member 831 exits the connecting hole 8251, and the connecting groove 8321 is separated from the seat plate 822, thereby realizing the detachment of the seat assembly too.

[0323] Further, as shown in FIGS. 68 to 72, in addition to the plurality of legs 6 mentioned above, the bracket assembly 200 also includes a leg base (also called a foot base or a base) 6212, a footrest 6213 movably connected to the plurality of leg 6, and a second sliding member 6214 slidably connected to a plurality of legs 6. The plurality of legs 6 are pivotally connected to the leg base 6212. The leg base 6212 is connected to the seat plate 822, and the plurality of legs 6 are configured to pivot relative to the seat plate 822 to switch the chair body 2000 between a raised state and a lowered state. The raised state means that the seat plate 822 of the chair body 2000 is relatively far away from the ground or its supporting surface, and the lowered state means that the seat plate 822 of the chair body 2000 is relatively close to the ground or its supporting surface. The footrest 6213 is movably connected to the plurality of legs 6. Specifically, each leg 6 is provided with a second sliding member 6214, and the footrest 6213 is pivotally connected to a plurality of second sliding members 6214. In this embodiment, the second sliding member 6214 is, for example, a sliding sleeve. Each sliding sleeve is sleeved outside the corresponding leg 6 and can slide relative to the leg 6. The footrest 6213 is pivotally connected to the plurality of sliding sleeves respectively. A reinforcing member 62131 is provided near the position where the footrest 6213 is pivotally connected to the sliding sleeve, so as to enhance the strength of the connection of the footrest 6213, thereby enhancing the strength of the footrest 6213. The footrest 6213 can move between the first position and the second position to drive the plurality of legs 6 to pivot.

[0324] Referring to FIG. 59, when the footrest 6213 is in the first position, the plurality of legs 6 are relatively far away from each other, and the chair body 2000 is in a lowered state. Referring to FIG. 60 as well, when the footrest 6213 is in the second position, the plurality of legs 6 are relatively close to each other, and the chair body 2000 is in a raised state. The footrest 6213 is closer to the seat plate 822 when the footrest 6213 is in the first position than when footrest 6213 is in the second position, that is, the second position of the footrest 6213 is lower than the first position thereof. In this way, when the child seat is switched from the first use mode as shown in FIG. 59 to the second use mode as shown in FIG. 60, the footrest 6213 can move from the first position to the second position, so that it is suitable for taller users to place their feet. Moreover, the height of the seat plate 822 is also increased accordingly, to improve the user's comfort. The same is true when the child seat is switched from the second use mode as shown in FIG. 60 to the first use mode as shown in FIG. 59. [0325] As shown in FIGS. 68 to 71, at least one of the plurality of legs 6 is provided with a first limiting member 6215. The first limiting member 6215 is located between the second sliding member 6214 and the seat plate 822. The first limiting member 6215 is adapted to abut against the second sliding member 6214, so as to restrict the footrest 6213 from continuing to slide upward from the first position. At least one of the plurality of legs 6 is provided with a second limiting member 6216. The second limiting member 6216 is adapted to abut against the second sliding member 6214, so as to restrict the footrest 6213 from continuing to slide downward from the second position. The first limiting member 6215 is located above the second limiting member 6216. The second sliding member 6214 can move between the first limiting member 6215 and the second limiting member 6216 to switch the chair body 2000 between the lowered state and the raised state. In this way, the height of the child seat is adjusted, so that the child seat can meet different use needs in different usage scenarios, further improving the use rate of the child seat.

[0326] As shown in FIGS. 68 to 72, the number of the legs 6 is four, and the number of the second sliding members 6214 is correspondingly provided with four. The four second sliding members 6214 are respectively pivotally connected to the footrests 6213. For convenience of description, one of the supporting legs 6 is taken as an example. In addition to the first leg 601 and the second leg 602 mentioned above, each leg 6 also includes a connecting joint 62113 and a mounting member 62114. The leg base 6212 is provided with a joint receiving groove 62122. The joint receiving groove 62122 faces the leg 6 and can receive at least a part of the connecting joint 62113. The connecting joint 62113 can rotate relative to the joint receiving groove 62122. The leg base 6212 is provided with a limiting hole 62123 that penetrates the bottom wall of the joint receiving groove 62122. The mounting member 62114 is disposed on the side of the leg base 6212 away from the leg 6 and is connected to the connecting joint 62113 through a fastener such as bolts. The mounting member 62114 has a limiting protrusion 621141, and at least a part of the limiting protrusion 621141 is received in the limiting hole 62123. When the limiting protrusion 621141 rotates along with the connecting joint 62113, the limiting protrusion 621141 can abut against the side wall of the limiting hole 62123, thereby limiting the rotation stroke of the connecting joint 62113, limiting the rotation stroke of the leg 6, and determining whether the chair body 2000 is in the raised state or the lowered state.

[0327] Specifically, an end of the first leg 601 is connected to the connecting joint 62113, and another end of the first leg 601 is detachably connected to the second leg 602. Optionally, the first leg 6oi and the second leg 602 are connected by, for example, snapping, threaded connection, or the like. In this embodiment, both the first leg 601 and the second leg 602 are metal tubes with a hollow inner cavity 62115. The first limiting member 6215 is disposed on the first leg 601, and the second limiting member 6216 is disposed on the second leg 602. The connecting joint 62113 is made of plastic, for example. The end of the second leg 602 away from the first leg 601 is provided with a foot (also called a foot pad) 603. The foot 603 can be detachably connected to the second leg 602 or the first leg 601. The foot 603 is made of plastic, for example, so that friction noise between the legs 6 and the ground or support surface can be reduced.

[0328] When the child seat is in the first use mode as shown in FIG. 59 or the second use mode as shown in FIG. 60, the foot 603 is connected to the second leg 602. When the child seat is in the third use mode as shown in FIG. 61 or the fourth use mode as shown in FIG. 62, the foot 603 can be detached from the second leg 602 and connected to the first leg 601 (as shown in FIGS. 61 and 62). [0329] Further, as shown in FIGS. 69, 71 and 72, the chair body 2000 also includes a folding mechanism (also called a closing mechanism) 923. The folding mechanism 923 is used to lock the second sliding member 6214 in the first position or the second position. When the folding mechanism 923 is in the locking state, the folding mechanism 923 can lock the second sliding member 6214 relative to the plurality of legs 6. When the folding mechanism 923 is in the unlocking state, the second sliding member 6214 can slide relative to the plurality of legs 6. For example, when the second sliding member 6214 is in the first position and the folding mechanism 923 is in the locking state, the chair body 2000 is locked in the lowered state. When the folding mechanism 923 is in the unlocking state (the second sliding member 6214 can be located in the first position or the second position), the second sliding member 6214 can slide between the first position and the second position, so that the chair body 2000 can freely switch between the raised state and the lowered state. Specifically, when the folding mechanism 923 is in the locking state, the folding mechanism 923 is engaged with the second sliding member 6214, so that the second sliding member 6214 cannot slide relative to the leg 6, thereby limiting the footrest 6213 to the first position. When the folding mechanism 923 is in the unlocking state, the folding mechanism 923 is disengaged from the second sliding member 6214, so that the second sliding member 6214 can slide relative to the leg 6, and the footrest 6213 can move freely between the first position and the second positions.

[0330] Referring to FIGS. 68 and 70, the number of folding mechanisms 923 is two. The two folding mechanisms 923 are symmetrically arranged on the bracket assembly 200, so that the footrest 6213 can be locked in the first position more stably. In other embodiments, the number of folding mechanisms 923 maybe one, two, or three, which is not limited hereto. For ease of explanation, one of the folding mechanisms 923 is taken as an example for description below.

[0331] In this embodiment, the folding mechanism 923 is disposed at the upper part of the leg, so that the chair body can be locked in a lowered state. In other embodiments not shown, a folding mechanism 923 can be additionally disposed at the lower part of the leg, so that the chair body can be locked in a lowered state and the raised state, respectively.

[0332] In some embodiments, as shown in FIGS. 69, 71 and 72, the folding mechanism 923 includes an engaging member 9231, a driving member 9232, a fixed base 9233, a folding reset member 9234, a folding operating member 9235 and a traction member 9236. The folding operating member 9235 is connected to the driving member 9232 through the traction member 9236, and the driving member 9232 is drivingly connected to the engaging member 9231. The fixed base 9233 is fixedly disposed on the leg 6. Specifically, the fixed base 9233 is received in the hollow inner cavity 62115 of the first leg 601, and the fixed base 9233 and the first limiting member 6215 disposed outside the hollow inner cavity 62115 are connected to the first leg 601 by fasteners such as bolts.

[0333] In this embodiment, the folding mechanism 923 includes two engaging members 9231, two driving members 9232, two fixed bases 9233, two folding reset members 9234, two traction members 9236, and one folding operating member 9235. The two engaging members 9231, the two driving members 9232, the two fixed bases 9233 and the two folding reset members 9234 are respectively disposed on two adjacent legs 6. An end of each of the two traction members 9236 is connected to the two traction members 9236 respectively. Another end of each of the two traction members 9236 is connected to the folding operating members 9235. In this way, one folding operating member 9235 can simultaneously control the movement of the driving members 9232 in the two legs 6, thereby controlling the movement of the engaging member 9231, and making the locking of the footrest 6213 more stable.

[0334] In other embodiments, the folding mechanism 923 may only include one folding operating member 9235, and one engaging member 9231, one driving member 9232, one fixed base 9233, one folding reset member, and one traction member 9236 which are disposed in one of the legs 6.

[0335] The following takes the folding operating member 9235 in the folding mechanism, and the engaging member 9231, the driving member 9232, the fixed base 9233, the folding reset member 9234 and the traction member 9236 disposed in one of the legs 6 as an example to explain its structure in detail.

[0336] As shown in FIGS. 69 and 71, the fixed base 9233 is provided with a guide groove 92331. The guide groove 92331 extends along a moving direction parallel to the driving member 9232, that is, the guide groove 92331 extends along a length direction parallel to the first leg 601. The engaging member 9231 can move between a fourth locking position (also called a folding locking position) and a fourth unlocking position (also called a folding unlocking position). At least a part of the engaging member 9231 is received in the hollow inner cavity 62115 of the first leg 601. An end of the engaging member 9231 is connected to the fixed base 9233. Specifically, the fixed base 9233 is provided with a first accommodation groove 92332, and the guide groove 92331 is disposed on the side wall of the first accommodation groove 92332. An end of the engaging member 9231 is insertably cooperated with the first accommodation groove 92332 and connected to the driving pin 9237. Specifically, the engaging member 9231 is provided with a driving groove 9239, and the extension direction of the driving groove 9239 is staggered and not perpendicular to the moving direction Ml of the engaging member 9231, that is, the extension direction of the driving groove 9239 is inclined relative to the moving direction of the engaging member 9231. The driving pin 9237 is insertably cooperated with the driving groove 9239 and insertably cooperated with the guide groove 92331 of the fixed base 9233. The driving pin 9237 can move along the guide groove 92331. Such an arrangement allows the engaging member 9231 to move along the extension direction of the first receiving groove 92332, thereby preventing the engaging member 9231 from being deflected when moving between the fourth locking position and the fourth unlocking position. Another end of the engaging component 9231 is the engaging end 92311. The first leg 601 is provided with a through hole 62116 for the engaging end 92311 to extend through. When the engaging member 9231 is in the fourth locking position, the engaging end 92311 of the engaging member 9231 extends through the through hole 62116, and the engaging end 92311 is insertably cooperated with the engaging hole 9238 of the second sliding member 6214. When the engaging member 9231 is in the fourth unlocking position, the engaging end 92311 of the engaging member 9231 is separated from the engaging hole 9238 so that the second sliding member 6214 can move relative to the leg 6.

[0337] In the chair body 2000 in this embodiment, the engaging member 9231 moves between the fourth locking position and the fourth unlocking position, so that the second sliding member 6214 is fixed or movable relative to the leg 6, thereby, the footrest 6213 is selectively locked in the first position, that is, the chair body 2000 is selectively locked in the lowered state.

[0338] As shown in FIGS. 69 and 71, the driving member 9232 is received in the hollow inner cavity 62115 of the first leg 601. The fixed base 9233 is provided with a second accommodation groove 92333. At least a part of the driving member 9232 is received in the second accommodation groove 92333 and can move relative to the second accommodation groove 92333. The driving member 9232 is connected to the driving pin 9237. In this embodiment, the moving direction M2 of the driving member 9232 is substantially parallel to the extension direction of the first leg 601, and the moving direction Ml of the engaging member 9231 is substantially perpendicular to the extension direction of the first leg 601. The driving pin 9237 is insertably cooperated with the driving groove 9239 and can move along the driving groove 9239. Specifically, the driving pin 9237 extends through the driving groove 9239 and the guide groove 92331 and drivingly connects the engaging member 9231 to the driving member 9232. In other embodiments not shown, the driving member 9232 maybe provided with a driving groove 9239, and the driving pin 9237 may be fixedly or detachably disposed on the engaging member 9231. The moving direction M2 is substantially perpendicular to the moving direction Ml.

[0339] As shown in FIGS. 69 and 71, the folding reset member 9234 is disposed between the driving member 9232 and the fixed base 9233. The folding reset member 9234 is suitable for biasing the driving member 9232 to drive the engaging member 9231 to move to the fourth locking position. The folding reset member 9234 may be an elastic member such as a spring or a spring leaf. In this embodiment, referring to FIGS. 59 and 71, a portion of the driving member 9232 received in the second receiving groove 92333 forms a boss 92321. The folding reset member 9234 is received in the second receiving groove 92333. Moreover, an end of the folding reset member 9234 abuts against the side wall of the second accommodation groove 92333, and another end of the folding reset member

9234 is sleeved on the boss 92321. Such arrangement can prevent the folding reset member 9234 from deflecting during deformation.

[0340] As shown in FIGS. 69, 71 and 72, the folding operating member 9235 is operatively disposed on the leg base 6212. Specifically, the folding operating member 9235 is operatively disposed on the side of the leg base 6212 away from the seat plate 822, that is, the folding operating member

9235 is operatively disposed on the lower side of the leg base 6212. An end of the traction member

9236 is received in the hollow inner cavity 62115 of the first leg 601 and connected to the driving member 9232. Another end of the traction member 9236 extend through the hollow inner cavity 62115 of the first leg 601 and is connected to the folding operating member 9235. The traction member 9236 is, for example, a driving cable such as a steel cable or a carbon fiber cable. When the folding operating member 9235 is operated, the folding operating member 9235 drives the driving member 9232 to move through the traction member 9236, so as to drive the engaging member 9231 to move from the fourth locking position to the fourth unlocking position. When the external force applied to the folding operating member 9235 is removed, under the elastic restoring force of the folding reset member 9234, the driving member 9232 drives the folding operating member 9235 to return to the initial position through the traction member 9236.

[0341] Referring to FIGS. 68 and 69, when the footrest 6213 is in the first position, the engaging hole 9238 of the second sliding member 6214 is opposite to the through hole 62116 of the leg 6, and the engaging end 92311 of the engaging member 9231 extends through the through hole 62116 and is engaged with the engaging hole 9238. At this time, the folding mechanism 923 is in the locking state, the second sliding member 6214 cannot slide relative to the leg 6, and the footrest 6213 is locked in the first position, that is, the chair body 2000 is locked in a lowered state. When it is necessary to adjust the height of the chair body 2000, the folding operating member 9235 is operated to move, so as to drive the driving member 9232 to move upward in the M2 direction through the traction member 9236, and the engaging member 9231 is driven to move from the fourth locking position to the fourth unlocking position along the Ml direction through the drivable connection between the driving pin 9237 and the driving groove 9239, so that the engaging end 92311 of the engaging member 9231 is disengaged from the engaging hole 9238 (see FIG. 71). At this time, an external force is applied to the footrest 6213 to move the footrest 6213 to the second position. When the footrest 6213 moves to a position where the second sliding member 6214 does not contact the engaging member 9231, the force exerted on the folding operating member 9235 is removed, the driving member 9232 moves downward in the M2 direction under the elastic restoring force of the folding reset member 9234. On the one hand, the driving member 9232 drives the folding operating member 9235 to move toward the initial position through the traction member 9236, and on the other hand, through the cooperation between the driving pin 9237 and the driving groove 9239, the engaging member 9231 is driven to return to the second locking position along the Ml direction. Since the through hole 62116 and the engaging hole 9238 are staggered at this time, the driving pin 9237 cannot be engaged with the engaging hole 9238. At this time, the second sliding member 6214 can move relative to the leg 6, that is, the footrest 6213 can move relative to the leg 6. When the footrest 6213 moves to a suitable position, that is, when the chair body 2000 is adjusted to a required height, the external force exerted on the footrest 6213 is removed. The footrest 6213 is fixed in the suitable position under the action of its own gravity and the friction between the second sliding member 6214 and the leg 6 (the suitable position can be, for example, the second position, or any position between the first position and the second position).

[0342] In some embodiments, as shown in FIGS. 73 to 75, the seat plate 822 includes a first seat plate 8221 and a second seat plate 8222. The first seat plate 8221 is provided with a first receiving groove 82211. The second seat plate 8222 is disposed at the groove opening of the first receiving groove 82211. Specifically, the first seat plate 8221 and the second seat plate 8222 are fixedly connected. The second seat plate 8222 is disposed around the leg base 6212 of the bracket assembly 200. The groove opening of the first receiving groove 82211 faces the direction of the leg base 6212, that is, the first seat plate 8221 is located above the leg base 6212. In this embodiment, the first seat plate 8221 and the second seat plate 8222 are connected through fasteners such as bolts. In other embodiments, the first seat plate 8221 and the second seat plate 8222 are detachably connected, for example, through clamping, threaded connection, or other means. In this embodiment, the leg base 6212 has a disk-shaped structure, the second seat plate 8222 has an annular structure provided around the leg base 6212, and the first seat plate 8221 has a disk-shaped structure capable of covering the leg base 6212 and the second seat plate 8222.

[0343] Referring to FIG. 73, the chair body 2000 also includes a connecting rod 826. An end of the connecting rod 826 is connected to the backrest 825, and another end of the connecting rod 826 extends into the first receiving groove 82211 and is connected to the second seat plate 8222. In other embodiments not shown, the other end of the connecting rod 826 may be connected to the first seat plate 8221.

[0344] FIG. 75, the first receiving groove 82211 has an annular first side wall 82212 and an annular second side wall 82213 surrounding the first side wall 82212. The second side wall 82213 is further away from the rotation axis R-R of the seat plate 822 than the first side wall 82212. The leg base 6212 is provided with a rotation connecting portion 62124. At least a part of the rotation connecting portion 62124 is received in the first receiving groove 82211 and abuts against the first side wall 82212 of the first receiving groove 82211, so that the seat plate 822 can rotate relative to the leg base 6212 about the rotation axis R-R. An opening 82223 is formed between the second seat plate 8222 and the first seat plate 8221. Specifically, the opening 82223 is formed between the second seat plate 8222 and the first side wall 82212. At least a part of the rotation connecting portion 62124 extends through the opening 82223 and is engaged with the first side wall 82212 of the first receiving groove 82211. In other embodiments not shown, the rotation connecting portion 62124 may abut against the second side wall 82213 of the first receiving groove 82211. In other embodiments not shown, the rotation connecting portion 62124 may also extend through the opening 82223 and be engaged with the second seat plate 8222, which is not limited hereto.

[0345] In some embodiments, as shown in FIGS. 73 to 75, the chair body 2000 also includes a rotation adjustment mechanism (also called a rotation positioning mechanism) 924. The rotation adjustment mechanism 924 can selectively position the seat plate 822 at a desired angle. Specifically, when the rotation adjustment mechanism 924 is in the unlocking state, the seat plate 822 can rotate relative to the leg base 6212. When the rotation adjustment mechanism 924 is in the locking state, the seat plate 822 cannot rotate relative to the leg base 6212, so that the seat plate 822 can be locked at a desired angle.

[0346] As shown in FIGS. 73 to 75, the rotation adjustment mechanism 924 includes a positioning member 9241, a positioning reset member 9242, and a positioning operating component 9243. The positioning operating member 9243 is drivingly connected to the positioning member 9241. The leg base 6212 is provided with a first positioning groove 9244, and the seat plate 822 is provided with a second positioning groove 9245. When the rotation adjustment mechanism 924 is in the locking state, the positioning member 9241 is in the third locking position, and the positioning member 9241 is engaged with the first positioning groove 9244 and the second positioning groove 9245 at the same time. That is, a part of the first positioning member 9241 is received in the first positioning groove

9244, and the other part of the positioning member 9241 is received in the second positioning groove

9245, so that the base plate 822 cannot rotate relative to the leg base 6212, thereby locking the base plate 822 at a desired angle. When the rotation adjustment mechanism 924 is in the unlocking state, the positioning member 9241 is in the third unlocking position, and the positioning member 9241 is disengaged from the second positioning groove 9245, that is, the positioning member 9241 is only received in the first positioning groove 9244. The seat plate 822 is allowed to rotate relative to the leg base 6212, so that the angle of the seat plate 822 relative to the leg base 6212 can be adjusted. In other embodiments not shown, when the rotation adjustment mechanism 924 is in the unlocking state, the positioning member 9241 is disengaged from the first positioning groove 9244, that is, the positioning member 9241 is only received in the second positioning groove 9245, so that the seat plate 822 can rotate relative to the leg base 6212, so that the angle of the seat plate 822 relative to the leg base 6212 can be adjusted.

[0347] As shown in FIGS. 73 to 75, the positioning member 9241 includes a positioning portion 92411 for be engaged with the second positioning groove 9245 and the first positioning groove 9244. The cross-section of the positioning portion 92411 is a non-circular rotationally symmetrical shape. In this embodiment, the cross section of the positioning portion 92411 is roughly cross-shaped, so that the seat plate 822 can be locked in four angular positions relative to the leg base 6212, and every two adjacent angular positions are 90° apart. The cross-shaped positioning portion 92411 may be formed of, for example, two mutually interlaced rectangles, or may be formed of, for example, two mutually interlaced ellipses. In other embodiments not shown, the positioning portion 92411 may also be formed by a rectangle or an ellipse, or the positioning portion 92411 may be formed by three or more mutually interlaced rectangles or three or more mutually interlaced ellipses. In other embodiments not shown, the cross-section of the positioning portion 92411 may also be a regular polygon, such as a regular triangle, a regular quadrilateral, a regular hexagon, etc. The specific shape of the cross-section of the positioning portion 92411 is not limited hereto. Those skilled in the art can select an appropriate cross-section shape of the positioning portion 92411 according to the required positioning angle. For example, if six angular positions are required, the cross-section of the positioning portion 92411 can be selected as three interlaced rectangles or ellipses, or a single regular hexagon. The shapes and sizes of the first positioning groove 9244 and the second positioning groove 9245 correspond to those of the positioning portion 92411 respectively.

[0348] As shown in FIG. 75, the positioning operating member 9243 is operatively disposed on the leg base 6212. The positioning operating portion 9243 is disposed on a side of the leg base 6212 away from the first positioning groove 9244. The positioning operating portion 9243 is drivingly connected to the positioning member 9241 through fasteners 9249 such as bolts. When being operated, the positioning operating member 9243 can drive the positioning member 9241 to move through fasteners such as bolts. The bottom of the first positioning groove 9244 or the bottom of the second positioning groove 9245 can abut against the positioning member 9241, thereby limiting the movement stroke of the positioning member 9241 and the movement stroke of the positioning operating member 9243.

[0349] As shown in FIG. 75, the positioning reset member 9242 is adapted to bias the positioning member 9241 to switch the rotation adjustment mechanism 924 to the locking state. The positioning reset member 9242 may be an elastic member such as a spring or a spring leaf. In this embodiment, the positioning reset member 9242 is a compression spring, and the positioning reset member 9242 is disposed between the positioning member 9241 and the leg base 6212. Specifically, referring to FIG. 73 as well, the positioning member 9241 has a positioning connecting portion 92412. The positioning portion 92411 is arranged around the positioning connecting portion 92412 and is rotationally symmetrical about the rotation axis R-R of the seat plate 822. A third receiving groove 92413 is formed on the side of the positioning connecting portion 92412 facing the leg base 6212, and the bottom of the first positioning groove 9244 is provided with a protruding column 92441. An end of the positioning reset member 9242 is sleeved on the protruding column 92441 and abuts against the bottom of the first positioning groove 9244. Another end of the positioning reset member 9242 abuts against the bottom of the third accommodation groove 92413. Such the arrangement prevents the positioning reset member 9242 from being deflected during the deformation process. When the positioning operating member 9243 is pulled downward, the positioning member 9241 is driven to move downward and compresses the positioning reset member 9242, so that the positioning member 9241 is disengaged from the second positioning groove 9245. When the tensile force applied to the positioning operating member 9243 is removed, under the elastic restoring force of the compressed positioning reset member 9242, the positioning member 9241 moves upward to the locking state in which the positioning member 9241 is engaged with the second positioning groove 9245, and drives the positioning operating member 9243 to move upward.

[0350] In some other embodiments, which are not shown, the positioning reset member 9242 may also be disposed between the seat plate 822 and the positioning member 9241, for example, between the bottom of the second positioning groove 9245 and the positioning member 9241. The positioning reset member 9242 is, for example, a compression spring. When the positioning operating member 9243 is pressed upward, the positioning member 9241 is driven to move upward and compresses the positioning reset member 9242, so that the positioning member 9241 is disengaged from the first positioning groove 9244. When the pressing force applied to the positioning operating member 9243 is removed, under the elastic restoring force of the compressed positioning reset member 9242, the positioning member 9241 moves downward to the locking state in which the positioning member 9241 is engaged with the second positioning groove 9245, and drives the positioning operating member 9243 to move downward.

[0351] In some embodiments, as shown in FIGS. 75 to 77, the positioning operating member 9243 can rotate relative to the leg base 6212. The end surface of the leg base 6212 facing the positioning operating member 9243 is provided with a positioning rib 62121. The positioning operating member 9243 is correspondingly provided with a retaining rib 92431. The retaining rib 92431 can operatively abut against the positioning rib 62121 to enable the rotation adjustment mechanism 924 to be maintained in the unlocking state, so that the seat plate 822 of the chair body 2000 can rotate freely for use by older children or adults. Specifically, the positioning rib 62121 is provided with an abutting end portion 62121a and an inclined surface 62121b. The inclined surface 62121b is connected to the abutting end portion 62121a and the lower end surface of the leg base 6212 respectively. When the positioning operating member 9243 is rotated, the retaining rib 92431 can move along the inclined surface 62121b to abut against the abutting end portion 62121a, thereby maintaining the rotation adjustment mechanism 924 in the unlocked state. The positioning rib 62121 is also provided with a limiting end portion 62121c protruding from the abutting end portion 62121a to prevent the positioning operating member 9243 from over-rotating and being misaligned with the abutting end portion 62121a. When there is no need to maintain the rotation adjustment mechanism 924 in the unlocking state, the positioning operating member 9243 is reversely rotated to stagger the retaining rib 92431 from the abutting end portion 62121a and the inclined surface 62121b, that is, the retaining rib 92431 is staggered from the positioning rib 62121, thereby, the rotation adjustment mechanism 924 is switched to the locking state. In this embodiment, the number of positioning ribs 62121 is at least two, for example, three, four, six, etc. At least two positioning ribs 62121 are rotationally symmetrically arranged relative to the rotation axis R-R of the seat plate 822. Correspondingly, the number of retaining ribs 92431 is at least two, for example, three, four, six, etc. At least two retaining ribs 92431 are rotationally symmetrically distributed relative to the rotation axis R-R of the seat plate 822.

[0352] In some embodiments, as shown in FIGS. 73 and 75, the bracket assembly 200 also includes rollers 6217. The roller 6217 is disposed on the leg base 6212 and can rotate relative to the leg base 6212. At least a part of the seat plate 822 is in rolling contact with the roller 6217. In this embodiment, the outer surface of the first side wall 82212 of the first receiving groove 82211 is in rolling contact with the roller 6217. Such arrangement can assist the seat plate 822 to rotate relative to the leg base 6212. Specifically, the roller 6217 has a first inclined surface 62171, and the seat plate 822 is provided with a second inclined surface 82214 surrounding the rotation axis R-R of the seat plate 822. The second inclined surface 82214 is in rolling contact with the first inclined surface 62171. In this embodiment, the number of rollers 6217 includes at least two, for example, three, five, six, etc. At least two rollers 6217 are symmetrically arranged relative to the rotation axis R-R of the seat plate 822.

[0353] The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the abovedescribed embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope of this specification.

[0354] The above-mentioned embodiments only express several implementation modes of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application should be determined by the appended claims.

Claims

1. A height adjustment mechanism disposed between a bracket assembly including a base, and a seat assembly including a seat, the height adjustment mechanism comprising: a supporting base integrated with the base or rotatably mounted on the base; and two adjustment members, wherein: the supporting base supports the seat through the two adjustment members; lower ends of the two adjustment members are respectively pivotally connected to the supporting base through two first shafts, and upper ends of the two adjustment members are respectively movably connected to the seat to form two connecting points; and the two adjustment members are rotatable respectively around corresponding first shafts to change positions of the two connecting points relative to the supporting base or the seat, so as to raise or lower the seat.

2. The height adjustment mechanism of claim 1, wherein the two adjustment members are rotatable in opposite directions respectively around the corresponding first shafts to change the positions of the two connecting points relative to the supporting base or the seat.

3. The height adjustment mechanism of claim 1 or 2, wherein: the seat has a first height and a second height relative to the supporting base, and the first height is greater than the second height; when the seat is at the first height, connecting points between the supporting base, the seat, and the two adjustment members define a first area; when the seat is at the second height, the connecting points between the supporting base, the seat, and the two adjustment members define a second area; and the first area is greater than the second area.

4. The height adjustment mechanism of any one of the preceding claims, wherein: the two adjustment members are arranged opposite and separated from each other in a first horizontal direction, and an axial direction of each first shaft is perpendicular to the first horizontal direction; when the two adjustment members rotate in opposite directions around the corresponding first shafts, the two connecting points are closer to or farther away from each other in the first horizontal direction while moving in a vertical direction; and/ or the height adjustment mechanism further includes two first locking members in one-to- one correspondence with the two adjustment members, and each of the two first locking members has a locking position where the first locking member locks a position of a corresponding adjustment member relative to the seat.

5. The height adjustment mechanism of claim 4, wherein: the seat is provided with a plurality of slots, and each of the two first locking members is selectively engaged with a corresponding one of the plurality of slots; and/or the height adjustment mechanism further includes a first elastic element configured to drive each of the two first locking members to be engaged with the seat.

6. The height adjustment mechanism of claim 4 or 5, further comprising two slide blocks slidably cooperated with the seat, wherein the two slide blocks are respectively pivotally connected to the upper ends of the two adjustment members through second shafts parallel to the first shaft, and the two slide blocks are in one-to-one correspondence with the two first locking members, and each of the two first locking members is movably connected to the corresponding slide block.

7. The height adjustment mechanism of claim 6, wherein: a receiving cavity is provided at a bottom of the seat, the two slide blocks are located in the receiving cavity, and each of the second shafts extends from the side wall of the receiving cavity and is pivotally connected to the upper end of the corresponding adjustment member; and the side wall of the receiving cavity is provided with first elongated holes corresponding to both ends of each second shaft.

8. The height adjustment mechanism of claim 6 or 7, wherein: each of the two first locking members moves in a vertical direction relative to the corresponding slide block to move to a locking position where the first locking member is engaged with the seat or an unlocking position where the first locking member is disengaged from the seat; and / or the height adjustment mechanism further includes two first driving members in one-to- one correspondence with the two first locking members, each of the first driving members is drivingly connected to the corresponding first locking member, and each of the first driving members drives the corresponding first locking member to move and disengage from the seat when subjected to an external force.

9. The height adjustment mechanism of claim 8, wherein: one of the first locking members and the corresponding first driving member is provided with a first pin, and another of the first locking members and the corresponding first driving member is provided with a driving slope, the first pin is parallel to the first shaft, and the driving slope abuts against the first pin; and when each of the first driving members is subjected to an external force, the driving slope and the first pin abuts against each other to drive the first locking member to move. to. The height adjustment mechanism of claim 8 or 9, further comprising at least one first unlocking member operatively connected to the two first driving members for applying the external force to each of the first driving members.

11. The height adjustment mechanism of any one of the claims 8 to 10, wherein: the height adjustment mechanism includes two first unlocking members in one-to-one correspondence with the two first driving members, and each of the first unlocking members is connected to the corresponding first driving member through a first traction member disposed in a protective jacket; and/or the height adjustment mechanism further includes a second elastic element configured to drive the at least one first unlocking member to return to its original position.

12. The height adjustment mechanism of any one of the preceding claims, wherein: the two adjustment members are arranged oppositely and separated from each other in a first horizontal direction; each of the adjustment members includes a pair of connecting arms arranged oppositely in a second horizontal direction perpendicular to the first horizontal direction, upper ends of the pair of connecting arms are movably connected to the seat, lower ends of the pair of connecting arms are pivotally connected to the supporting base through the first shafts, and the pair of connecting arms are connected to each other through a side plate; and at least one of the two opposite surfaces of the pair of connecting arms is provided with a sliding slot, and the seat is provided with a boss slidably cooperated with the sliding slot.

13. The height adjustment mechanism of any one of the preceding claims, wherein: the two adjustment members are arranged oppositely and separated from each other in a first horizontal direction, and an axial direction of the first shaft is perpendicular to the first horizontal direction; the supporting base is provided with two supporting members arranged oppositely in the first horizontal direction, and the two supporting members are in one-to-one correspondence with the two adjustment members; one of an upper end of the supporting member and the lower end of the adjustment member is provided with a mounting hole, and another of the upper end of the supporting member and the lower end of the adjustment member is provided with the first shaft, the first shaft being pivotally connected to the mounting hole; and an angle limiting mechanism is disposed between at least one pair of supporting member and corresponding adjustment member, and the angle limiting mechanism is configured to limit a range of rotation angle of the adjustment member.

14. The height adjustment mechanism of claim 13, wherein: a distance between the upper ends of the two supporting members is greater than a distance between lower ends of the two supporting members; and/ or the angle limiting mechanism includes: a first arc-shaped groove located on a hole wall of the mounting hole and extending in a circumferential direction; and an elastic telescopic pin mounted on the first shaft and adapted to be inserted into the first arc-shaped groove.

15. The height adjustment mechanism of claim 14, wherein the hole wall of the mounting hole is provided with an inclined surface configured to guide the elastic telescopic pin to be inserted into the first arc-shaped groove.

16. A seat adjustment device disposed between a bracket assembly and a seat assembly, the seat adjustment device comprising: a first adjustment column connected to a seat of the seat assembly; a second adjustment column connected to a base of the bracket assembly, and insertably cooperated with the first adjustment column; and a height adjustment mechanism disposed between the first adjustment column and the second adjustment column, and switchable between a locking state and an unlocking state, wherein, when the height adjustment mechanism is in the locking state, the first adjustment column is fixed at a certain height position relative to the second adjustment column, and when the height adjustment mechanism is in the unlocking state, the first adjustment column is movable relative to the second adjusting column.

17. The seat adjustment device of claim 16, wherein the height adjustment mechanism includes: a plurality of adjustment holes disposed at one of the first adjustment column and the second adjustment column; and a height locking member movably disposed on another of the first adjustment column and the second adjustment column, and switchable between a first locking position and a first unlocking position, wherein, when the height locking member is at the first locking position, the height locking member is engaged with at least one of the plurality of adjustment holes, and when the height locking member is at the first unlocking position, the height locking member is disengaged from the at least one of the adjustment holes.

18. The seat adjustment device of claim 17, wherein the height adjustment mechanism further includes a height driving member, one of the height locking member and the height driving member is provided with a first driving groove, another of the height locking member and the height driving member is provided with a first driving pin, an extension direction of the first driving groove is inclined relative to a moving direction of the height locking member, the first driving pin is insertably cooperated with the first driving groove and is movable along the first driving groove, and the height driving member is configured to drive the height locking member to move between the first locking position and the first unlocking position.

19. The seat adjustment device of claim 18, wherein: the plurality of adjustment holes is disposed on the second adjustment column, and the height locking member is disposed on the first adjustment column; and the height adjustment mechanism further includes a fixed base connected to the first adjustment column, the fixed base is provided with a guide groove, an extension direction of the guide groove is perpendicular to an axial direction of the first adjustment column, and the first driving pin is insertably cooperated with the guide groove and is movable along the guide groove.

20. The seat adjustment device of claim 18 or 19, wherein: the height adjustment mechanism further includes a first reset member adapted to bias the height driving member to move toward the first locking position; and/ or the height adjustment mechanism further includes: a height operating member switchable between a first position and a second position; and a traction member having an end connected to the height driving member, and another end connected to the height operating member, wherein the height operating member is operable to drive the height driving member to move through the traction member, so as to drive the height locking member from the first locking position to the first unlocking position.

21. The seat adjustment device of claim 20, wherein: the height adjustment mechanism further includes a second reset member adapted to bias the height operating member to move toward the first position; and/or the seat adjustment device further includes a mounting base, through which the first adjustment column is connected to the seat, the mounting base including: an upper cover connected to a bottom of the seat and the first adjustment column; and a lower cover enclosed with the upper cover to form a first receiving cavity, at least a part of the height operating component being received in the first receiving cavity.

22. The seat adjustment device of claim 21, wherein the mounting base further includes a connecting tube arranged around an outer periphery of the first adjustment column and enclosed with the adjustment column to form a second receiving cavity, the second receiving cavity is connected to the first receiving cavity, and at least a part of the traction member is received in the second receiving cavity.

23. The seat adjustment device of claim 22, wherein the height adjustment mechanism further includes a fixed base arranged on an end of the first adjustment column away from the seat, at least a part of the fixed base is received in the second receiving cavity, and the height driving member and the height locking member are received in the second receiving cavity, and are respectively movably connected to the fixed base.

24. The seat adjustment device of claim 22 or 23, further comprising an anti-separation mechanism, wherein the anti-separation mechanism includes: an elastic finger disposed on the connecting tube, and having a hook portion protruding in a direction away from the second receiving cavity; and an engaging groove disposed on the bracket assembly, an extension direction of the engaging groove being parallel to the axial direction of the second adjustment column, wherein the hook portion is movable along the engaging groove, and an end of the engaging groove limits a movement stroke of the hook portion.

25. The seat adjustment device of claim 24, wherein the bracket assembly further includes an adjustment base connected to the base, the adjustment base is disposed at least partially around the second adjustment column and is connected to the second adjustment column, and the engaging groove is disposed on the adjustment base.

26. The seat adjustment device of any one of the claims 22 to 25, wherein the bracket assembly further includes an adjustment base relatively rotatably connected to the base, a first accommodation groove is defined between the adjustment base and the second adjustment column, the connecting tube is slidably cooperated with the first accommodation groove, and the connecting tube is non-rotatable relative to the adjustment base.

27. The seat adjustment device of any one of the claims 16 to 26, wherein the first adjustment column is provided with a hollow inner cavity, and the second adjustment column is inserted into the hollow inner cavity and is movable along the hollow inner cavity.

28. The seat adjustment device of claim 27, wherein an outer surface of the second adjustment column is provided with a protrusion, and the protrusion abuts against and is slidably cooperated with a cavity wall of the hollow inner cavity of the first adjustment column.

29. The seat adjustment device of claim 28, wherein an end of the first adjustment column away from the seat assembly is provided with a fixed base, and the fixed base is provided with a groove adapted to cooperate with the protrusion and allowing the protrusion to pass therethrough.

30. A rotation adjustment mechanism disposed between a seat assembly and a bracket assembly that are rotatable relative to each other, so as to operatively lock a circumferential position of the seat assembly relative to the bracket assembly.

31. The rotation adjustment mechanism of claim 30, wherein: the seat assembly is mounted on a supporting base, the bracket assembly includes a base, and the supporting base is rotatably mounted on the base; and the rotation adjustment mechanism includes a third locking member mounted on one of the supporting base and the base, another of the supporting base and the base is provided with a plurality of positioning holes in the circumferential direction, and the third locking member is selectively inserted into one of the plurality of positioning holes to lock a position of the supporting base relative to the seat.

32. The rotation adjustment mechanism of claim 30 or 31, wherein: the seat assembly is connected to the bracket assembly through an adjustment base; and the rotation adjustment mechanism is operably disposed on the bracket assembly, the rotation adjustment mechanism includes an unlocking state and a locking state, when the rotation adjustment mechanism is in the unlocking state, the adjustment base is rotatable relative to the bracket assembly or the seat assembly to adjust circumferential relative positions of the seat assembly and the bracket assembly; and when the rotation adjustment mechanism is in the locking state, the adjustment seat is non-rotatable relative to the bracket assembly and the seat assembly, so as to lock the circumferential relative positions of the seat assembly and the bracket assembly.

33. The rotation adjustment mechanism of claim 32, wherein: the seat assembly is connected to the first adjustment column, the adjustment base is connected to the second adjustment column, and the second adjustment column is insertably cooperated with the first adjustment column; and a height adjustment mechanism is disposed between the first adjustment column and the second adjustment column, and the height adjustment mechanism is switchable between the locking state and the unlocking state, when the height adjustment mechanism is in the locking state, the first adjustment column is fixed at a certain height position relative to the second adjustment column, and when the height adjustment mechanism is in the unlocking state, the first adjustment column is movable relative to the second adjustment column.

34. The rotation adjustment mechanism of claim 32 or 33, comprising: a plurality of insertable slots disposed in one of the bracket assembly and the adjustment base; and a rotation locking member disposed on another of the bracket assembly and the adjustment base, the rotation locking member being switchable between a second locking position and a second unlocking position, wherein, when the rotation locking member is in the second locking position, the rotation locking member is engaged with at least one of the plurality of insertable slots, so that the adjustment base is non-rotatable relative to the bracket assembly, and wherein, when the rotation locking member is in the second unlocking position, the rotation locking member is disengaged from the plurality of insertable slots, so that the adjustment base is rotatable relative to the bracket assembly.

35. The rotation adjustment mechanism of claim 34, wherein the rotation locking member is disposed on the adjustment base, and the adjustment base is provided with a second through hole, through which the locking member is movably inserted.

36. The rotation adjustment mechanism of claim 34 or 35, further comprising: a rotation operating member mounted to the adjustment base, wherein the rotation operating member is drivingly connected to the rotation locking member, so as to drive the rotation locking member to switch between the second locking position and the second unlocking position.

37. The rotation adjustment mechanism of claim 36, wherein: the rotation locking member is provided with a first driving surface, the rotation operating member is provided with a second driving surface abutting against the first driving surface, and the rotation operating member is operable to push the first driving surface via the second driving surface, thereby driving the rotation locking member to switch to the second unlocking position; or the rotation locking member is provided with an insertion slot, a side wall of the insertion slot forms a first driving surface, the rotation operating member includes an insertion portion, and a side wall of the insertion portion forms a second driving surface inclined relative to an extension direction of the rotation locking member, the insertion portion is insertably cooperated with the insertion slot, and the second driving surface abuts against the first driving surface.

38. The rotation adjustment mechanism of claim 36 or 37, wherein the bracket assembly is provided with an accommodation hole, the adjustment base is at least partially received in the accommodation hole, the rotation operating member is movably connected to the adjustment base, and the rotation operating member is at least partially exposed from the accommodation hole for operation.

39. The rotation adjustment mechanism of any one of the claims 34 to 38, wherein the rotation adjustment mechanism further includes a rotation reset member adapted to bias the rotation locking member to move toward the second locking position.

40. The rotation adjustment mechanism of claim 39, wherein the rotation locking members are arranged in pairs, and the rotation reset member is connected or abuts between two rotation locking members in a pair to simultaneously bias the two rotation locking members.

41. The rotation adjustment mechanism of any one of the claims 30 to 40, wherein the bracket assembly includes a leg base connected to the plurality of legs, the seat assembly is mounted on the seat plate, and the seat plate is rotatably connected to the leg base; and wherein the rotation adjustment mechanism is disposed between the leg base and the seat plate, when the rotation adjustment mechanism is in the unlocking state, the seat plate is rotatable relative to the leg base, and when the rotation adjustment mechanism is in the locking state, the seat plate is non-rotatable relative to the leg base.

42. The rotation adjustment mechanism of claim 41, further comprising: a positioning member having a third locking position and a third unlocking position, wherein: the leg base is provided with a first positioning groove, and the seat plate is provided with a second positioning groove; when the rotation adjustment mechanism is in the locking state, the positioning member is in the third locking position, and the positioning member is engaged with both the first positioning groove and the second positioning groove; and when the mechanism is in the unlocking state, the positioning member is in the third unlocking position, and the positioning member is disengaged from at least one of the first positioning groove and the second positioning groove.

43- The rotation adjustment mechanism of claim 42, wherein: the positioning member includes a positioning portion adapted to be engaged with the second positioning groove and the first positioning groove, and a cross-section of the positioning portion has a non-circular rotationally symmetrical shape; and/ or the rotation adjustment mechanism further includes a positioning reset member adapted to bias the positioning member to move toward the third locking position, the positioning reset member abuts or is connected between the positioning member and the leg base.

44. The rotation adjustment mechanism of claim 42 or 43, further comprising a positioning operating member drivingly connected to the positioning member, wherein the positioning operating member is operably disposed on the leg base, and the positioning operating member is operable to drive the positioning member to move toward the third unlocking position.

45. The rotation adjustment mechanism of claim 44, wherein the positioning operating member is disposed on a side of the leg base away from the first positioning groove, and the positioning operating member is connected to the positioning member through a fastener.

46. The rotation adjustment mechanism of any one of the claims 41 to 45, wherein the seat plate is provided with a first receiving groove, the leg base is provided with a rotation connecting portion, and at least a part of the rotation connecting portion is received in the first receiving groove and abuts against a side wall of the first receiving groove, so that the seat plate is rotatable about a rotation axis relative to the leg base.

47. The rotation adjustment mechanism of claim 46, wherein the seat plate includes a first seat plate and a second seat plate, the first seat plate is provided with a first receiving groove, the second seat plate is arranged at a groove opening of the first receiving groove, an opening is formed between the second seat plate and the first seat plate, and at least a part of the rotation connecting portion extends into the opening and is engaged with a groove wall of the first receiving groove.

48. The rotation adjustment mechanism of any one of the claims 41 to 47, wherein: the seat plate includes a first seat plate and a second seat plate, which enclose to form a first receiving groove, a connecting rod is inserted into the first receiving groove, and a part of the connecting rod extending out from the first receiving groove is connected to a backrest; and/or the bracket assembly further includes a roller rotatably disposed on the leg base, the roller is provided with a first slope, and the seat plate is provided with a second slope surrounding a rotation axis of the seat plate and is in rolling contact with the first slope.

49. The rotation adjustment mechanism of claim 44, optionally in combination with any one of the claims 45 to 48, wherein the positioning operating member is rotatably disposed on the leg base, the leg base is provided with a positioning rib, and the positioning operating member is provided with a retaining rib abutting against the positioning rib to maintain the positioning member in the third unlocking position.

50. A chair comprising: the height adjustment mechanism according to any one of claims 1 to 15; and/or the seat adjustment device according to any one of claims 16 to 29; and/or the rotation adjustment mechanism according to any one of claims 30 to 49.

51. A chair comprising a bracket assembly, wherein the bracket assembly includes a plurality of legs and a folding mechanism configured to unfold or fold the plurality of legs.

52. The chair of claim 51, wherein the folding mechanism includes: an adjustment base; a plurality of connecting members mounted on the adjustment base; and at least one second locking member, wherein the adjustment base is slidably connected to the plurality of legs through the plurality of connecting members, the at least one second locking member is configured to be engaged with at least one of the plurality of legs, so as to lock relative positions of the adjustment base and the at least one of the plurality of legs.

53. The chair of claim 51 or 52, wherein two or more lock slots are disposed on the at least one of the plurality of legs, and the two or more lock slots are spaced apart along a length direction of the at least one of the plurality of legs, so as to be selectively engaged with the at least one second locking member.

54. The chair of claim 52, optionally in combination with claim 53, wherein: the chair further includes a second unlocking member mounted on the adjustment base and operably connected to at least one second locking member; and/or each of the plurality of connecting members has a notch, each of the plurality of legs is provided with a sliding rail, and each of the plurality of connecting members, via its notch, is slidably connected to the sliding rail on the corresponding leg.

55- The chair of any one of the claims 51 to 54, wherein: the bracket assembly includes a base with a slideway extending in a vertical direction, and the plurality of legs are respectively pivotally connected to the base, the folding mechanism includes: a first sliding member slidably cooperated with the slideway; and a plurality of linking members connected between the first sliding member and the plurality of legs, wherein, when the first sliding member moves along the slideway, the plurality of linking members drive the plurality of legs to unfold or fold synchronously.

56. The chair of claim 55, wherein the folding mechanism further includes: a stabilizing member connected to the first sliding member through at least one connecting member, thereby allowing the stabilizing member to move in a vertical direction along with the first sliding member, the stabilizing member having a rotation axis parallel to the vertical direction; and at least one first motion conversion mechanism disposed between the stabilizing member and the base, wherein, when the stabilizing member moves in the vertical direction, each of the first motion conversion mechanisms drives the stabilizing member to rotate about the rotation axis relative to the first sliding member.

57. The chair of claim 56, wherein: one of the stabilizing member and the first sliding member is provided with at least one arc-shaped hole, another of the stabilizing member and the first sliding member is provided with at least one through hole, and the at least one connecting member is inserted into the at least one arc-shaped hole and the at least one through hole along the vertical direction; or the at least one connecting member includes at least two engaging hooks extending from the stabilizing member or the first sliding member, and each of the engaging hooks extends in the vertical direction.

58. The chair of claim 56 or 57, wherein each of the first motion conversion mechanisms includes: a first driving chute disposed on one of the base and the stabilizing member; and a first driving pin disposed on another of the base and the stabilizing member and slidably cooperated with the first driving chute. 59- The chair of any one of the claims 55 to 58, wherein the slideway is formed by a column portion extending in the vertical direction, and the first sliding member is sleeved on an outside of the column portion.

60. The chair of claim 56, optionally in combination with any one of the claims 57 to 59, wherein the slideway is formed by a column portion extending in the vertical direction, the first sliding member and the stabilizing member are sleeved on the outside of the column portion, and the at least one first motion conversion mechanism is disposed between the stabilizing member and the column portion.

61. The chair of any one of the claims 55 to 60, wherein the folding mechanism further includes at least one locking member mounted to the base and configured to lock the first sliding member, so as to limit a movement of the first sliding member relative to the slideway.

62. The chair of claim 61, wherein the folding mechanism further includes: at least one unlocking member operatively connected to the at least one locking member for driving the at least one locking member to unlock the first sliding member; and/ or at least one elastic member configured to drive the at least one locking member to lock the first sliding member.

63. The chair of any one of the claims 55 to 62, wherein: the first sliding member includes at least one locking portion, and each of the at least one locking portion includes a locking recess; each of the at least one locking member includes a plurality of locking protrusions, which extend in a transverse direction and are spaced apart in a vertical direction; and the locking recesses are selectively cooperated with the plurality of locking protrusions to lock the first sliding member at different positions on the slideway.

64. The chair of any one of the claims 55 to 63, wherein: the first sliding member includes at least one locking portion, each of the locking portions includes a plurality of locking recesses, and the plurality of locking recesses are spaced apart in a vertical direction; each of the at least one locking member includes a locking protrusion extending in a transverse direction; and the plurality of locking recesses is selectively cooperated with the locking protrusions to lock the first sliding member at different positions on the slideway.

65. The chair of claim 62, optionally in combination with claim 63 or 64, wherein: each of the at least one unlocking member is mounted on the base and is movable in a vertical direction; a second movement conversion mechanism is disposed between each of the at least one unlocking member and each of the at least one locking member, and is configured to convert a movement of each of the at least one unlocking member in the vertical direction to a movement of each of the at least one locking member in a transverse direction, so as to allow each of the at least one locking member to lock or unlock the first sliding member.

66. The chair of claim 65, wherein the second movement conversion mechanism includes: a second driving chute disposed on one of the corresponding unlocking member and the corresponding locking member; and a second driving pin disposed on another of the corresponding unlocking member and the corresponding locking member, and slidably cooperated with the second driving chute.

67. The chair of claim 56, optionally in combination with any one of the claims 57 to 66, wherein: the base includes a receiving cavity, wherein the slideway, the first sliding member and the stabilizing member are located in the receiving cavity, and the base is provided with a plurality of first through grooves communicating with the receiving cavity, and first ends of the plurality of linking members are pivotally connected to the first sliding member after extending through the plurality of first through grooves; and/or covers are respectively mounted on the plurality of legs, each of the covers is provided with a second through groove, and a second end of each of the plurality of linking members is pivotally connected to one of the plurality of legs after extending through the second through groove.

68. The chair of any one of the claims 51 to 67, wherein: the bracket assembly is mounted on a seat plate, and the plurality of legs is configured to be pivotable relative to the seat plate, so that the chair is switchable between a raised state and a lowered state; the bracket assembly further includes a footrest movably connected to the plurality of legs, the footrest is movable between a first position and a second position to drive the plurality of legs to pivot; and when the footrest is at the first position, the plurality of legs is unfolded, so that the chair is in the lowered state, and when the footrest is at the second position, the plurality of legs is folded, so that the chair is in the raised state.

69. The chair of claim 68, wherein each of the plurality of legs is provided with a second sliding member pivotally connected to the footrest, so that the footrest is slidable together with the second sliding member between the first position and the second position.

70. The chair of claim 69, wherein the folding mechanism includes: an engaging member movably disposed on at least one of the plurality of legs, the engaging member being switchable between a fourth locking position and a fourth unlocking position; and an engaging hole disposed on the second sliding member, wherein when the folding mechanism is in the locking state, the engaging member is in the fourth locking position, and is engaged with the engaging hole, so as to lock the second sliding member relative to the legs, and when the folding mechanism is in the unlocking state, the engaging member is in the fourth unlocking position, and is disengaged from the engaging hole.

71. The chair of claim 70, wherein the folding mechanism further includes a driving member, wherein one of the driving member and the engaging member is provided with a driving groove, another of the driving member and the engaging member is provided with a driving pin, an extension direction of the driving groove is inclined relative to a moving direction of the engaging member, and the driving pin is insertably cooperated with the driving groove and movable along the driving groove to drive the engaging member to move between the fourth locking position and the fourth unlocking position.

72. The chair of claim 70 or 71, wherein the folding mechanism further includes: a fixed base fixedly disposed on at least one of the plurality of legs, the fixed base being provided with a guide groove extending parallel to the moving direction of the driving member, and the driving pin being insertably cooperated with the guide groove and being movable along the guide groove; and/or a folding reset member adapted to bias the driving member so that the driving member drives the engaging member to move toward the fourth locking position.

73. The chair of claim 71, optionally in combination with claim 72, wherein the folding mechanism further includes: a folding operating member movably disposed on the bracket assembly; and a traction member having an end connected to the driving member, and another end connected to the folding operating member, wherein the folding operating member is operable to drive the driving member to move through the traction member, so that the engaging member is driven to move from the fourth locking position to the fourth unlocking position. 74- The chair of any one of the claims 69 to 73, wherein: the plurality of legs is provided with a hollow inner cavity, and at least a part of the folding mechanism is received in the hollow inner cavity; and/ or at least one of the plurality of legs is provided with a first limiting member adapted to abut against the second sliding member to limit the footrest from sliding upward from the first position; and/or at least one of the plurality of legs is provided with a second limiting member adapted to abut against the second sliding member to limit the footrest from moving downward from the second position.

75. The chair of any one of the claims 68 to 74, wherein each of the plurality of legs includes a first leg and a second leg, wherein one end of the first leg is connected to the seat plate, and another end of the first leg is detachably connected to the second leg.

76. The chair of any one of the claims 51 to 75, further comprising a seat detachment mechanism, a seat assembly being detachably connected to a mounting base through the seat detachment mechanism, wherein the seat detachment mechanism includes: an engaging hole disposed on the mounting base; and a detachment locking member disposed on the seat assembly, the detachment locking member having a hook and being movable between a third position and a fourth position, wherein, when the detachment locking member is in the third position, the hook is engaged with the engaging hole, so that the seat assembly is fixed relative to the mounting base, and when the detachment locking member is in the fourth position, the hook is disengaged from the engaging hole, so that the seat assembly is detachable from the mounting base.

77. The chair of claim 76, wherein the mounting base is provided with a connecting groove (4358) , and the engaging hole is disposed on a side wall of the connecting groove and is connected to the connecting groove, the detachment locking member is insertably cooperated with the connecting groove, and the detachment locking member is movable in a direction parallel to a bottom wall of the connecting groove, and is movable between the third position and the fourth position.

78. The chair of claim 76 or 77, wherein the seat detachment mechanism further includes: an engaging recess (545) disposed on the mounting base; a detachment unlocking member (542) operably disposed on the seat assembly, the detachment unlocking member having an engaging protrusion (5421) , and the detachment unlocking member being switchable between a sixth unlocking position and a sixth locking position, wherein, when the detachment unlocking member is in the sixth locking position, the engaging protrusion is engageable with the engaging recess to limit the detachment locking member in the third position, and when the detachment locking member is in the sixth unlocking position, the engaging protrusion is disengaged from the engaging recess, so that the detachment unlocking member is switchable between the third position and the fourth position; and a detachment reset member (543) adapted to bias the detachment unlocking member, so that the detachment unlocking member moves toward the sixth locking position.

79. The chair of claim 78, wherein the seat assembly is provided with a receiving hole, the engaging protrusion of the detachment unlocking member is adapted to extend through the receiving hole and to be engaged with the engaging recess, and an end of the detachment unlocking member away from the engaging protrusion is provided with an operating recess at least partially extending out of the receiving hole.

80. The chair of claim 78 or 79, wherein the seat assembly is provided with a second receiving groove, the detachment unlocking member is further provided with an abutting portion, at least a part of the abutting portion is received in the second receiving groove, the detachment reset member is received in the second receiving groove, and two ends of the detachment reset member respectively abut against a groove wall of the second receiving groove and the abutting portion.

81. The chair of any one of the claims 51 to 80, wherein: the bracket assembly is mounted on a seat plate, and the seat plate is equipped with a backrest; the seat assembly includes a seat and a backrest portion, the backrest portion is provided with a first connecting member, and the seat assembly is detachably connected to the backrest portion through the first connecting member; and when the seat assembly is connected to the backrest, the chair is in a first use state, and when the seat assembly is separated from the backrest, the chair is in a second use state.

82. The chair of claim 81, wherein: the backrest is provided with a connecting hole, and the first connecting member is rotatably disposed on the seat assembly and is switchable between a fifth locking position and a fifth unlocking position; and when the first connecting member is in the fifth unlocking position, the first connecting member is movable along an extension direction of the connecting hole, and the first connecting member is rotatable to the fifth unlocking position, and when the first connecting member is in the fifth locking position, the seat assembly and the first connecting member are capable of being located on two sides of the backrest respectively, and the first connecting member abuts against the backrest, so that the seat assembly and the backrest are relatively fixed.

83. The chair of claim 82, wherein: the backrest portion is provided with a connecting protrusion capable of being insertably cooperated with the connecting hole, and the first connecting member is rotatably connected to the connecting protrusion; and/or a bottom of the seat assembly is provided with a second connecting member extending downward and forming a connecting groove thereon, and the second connecting member is configured to be engaged with the seat plate through the connecting groove.

84. The chair of claim 82 or 83, wherein: a backside of backrest is provided with a positioning protrusion, the first connecting member is correspondingly provided with a positioning recess, and when the first connecting member is in the fifth locking position, the positioning protrusion is engaged with the positioning recess; and/or a side of the backrest away from the seat assembly is provided with a recess, and when the first connecting member is in the fifth locking position, the first connecting member abuts against a bottom wall of the recess.

85. The chair of any one of the claims 51 to 84, wherein: a seat assembly includes a seat and a tray, wherein the tray is connected to the seat through a tray adjustment mechanism, and the tray adjustment mechanism includes: a plurality of positioning slots disposed on a side of the seat; and a tray unlocking member having an engaging portion, the tray unlocking member being movably disposed on the tray and having a seventh locking position and a seventh unlocking position, wherein, when the tray unlocking member is in the seventh locking position, the engaging portion is engaged with at least one of the plurality of positioning slots to fix the tray on the seat, and when the tray unlocking member is in the seventh unlocking position, the engaging portion is disengaged from the plurality of positioning slots, so that the tray is detachable from the seat or is movable relative to the seat.

86. The chair of claim 85, wherein: the tray has a front face capable of bearing loads and a back face away from the front face, the tray unlocking member is disposed on the back face, the tray unlocking member further has a second operating portion, and the second operating potion protrudes from the engaging portion and extends away from the back surface; and/or the tray adjustment mechanism further includes an adjustment reset member disposed between the tray unlocking member and the tray, and the adjustment reset member is adapted to bias the tray unlocking member, so that the tray moves toward the seventh locking position.

87. The chair of claim 85 or 86, wherein: one of the tray and the tray unlocking member is provided with an elongated groove, and another of the tray and the tray unlocking member is provided with a connecting pin insertably cooperated with the elongated groove; and/ or the tray is provided with a connecting plate arranged along a front and rear direction of the chair, the connecting plate is provided with a hole, and by passing through the hole, the engaging portion is capable of being engaged with or disengaged from the plurality of positioning slots; and/or the tray is further provided with a limiting portion capable of abutting against the side of the seat to limit a movement stroke of the tray.