CN215776747U - Seat back assembly with adjustable seat depth - Google Patents

Abstract

The utility model discloses a seat-depth-adjustable chair back assembly which comprises a back support member, a back support and a support adjusting mechanism, wherein the back support member comprises an upper back assembly and a lower back assembly, and the upper part of the lower back assembly is rotatably connected to the back support; the two ends of the supporting and adjusting assembly are respectively rotatably connected with the back support and the lower back assembly and are configured to support the lower back assembly to stay at corresponding positions after the lower back assembly rotates; compared with the prior art, the chair back component divides the back support into an upper back component and a lower back component, and the lower back component is rotatably connected to the back bracket and supported by the support adjusting component to stay at the corresponding position after rotation; because the rotating connection point is positioned at the upper part of the lower back component, the lower back component can deflect forwards or backwards when rotating, and the functions of supporting waist and adjusting seat depth are realized; because the rotation connecting point is positioned at the upper part of the lower back component, the lower back component deflects towards the front upper part or the rear lower part when moving, the height of the top waist can be adjusted while the seat depth is adjusted, so that the chair is suitable for people with different rising heights.

Description

Seat back assembly with adjustable seat depth

Technical Field

The utility model relates to the field of office furniture, in particular to a chair back component with adjustable seat depth.

Background

With the rapid development of science and technology and the increasing social pressure, health has become an important topic of increasing social attention. Although the science and technology liberates the physical labor, people get involved in mental labor of long-time sitting on a desk, the number of groups of long-time sitting in China is increased continuously, the positions of the buttocks of the people in the long-time sitting can be adjusted continuously to ensure the comfort of sitting, and when a user works, the user sits in the front two thirds position of the seat cushion most of the time, and the waist and the back of the user can not be supported by the backrest. With the increase of people, various age-incompatible waist diseases caused by sedentary behaviors are generated.

Chair of regulation lumbar support on market generally has the short problem of stroke that lumbar support piece adjusted, and some chairs have single back frame, back of the body frame cladding screen cloth, and human back is supported by this back of the body frame, leans on in back of the body frame lower part is equipped with an adjustable waist again to adjust the seat deeply, like chinese utility model patent CN201720443193.7, it carries out the seat with the gasbag as adjustable waist and adjusts deeply and realize a waist effect, but the stroke is less, and the operation is difficult.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a seat back assembly with adjustable seat depth, wherein the key point is that the seat depth is adjusted by pushing and pulling the lower back assembly by a user.

The technical scheme of the utility model is realized as follows:

a seat back assembly with adjustable seat depth, comprising:

a back bracket configured to support a body of the back support;

a back support configured to support a human lumbar back; the back support comprises an upper back component and a lower back component which are separated up and down, the upper back component is arranged on the back support, and the upper part of the lower back component is rotatably connected on the back support;

and the supporting and adjusting assembly is arranged between the back support and the lower back assembly and is connected to the lower part of the back support, and the supporting and adjusting assembly is configured in such a way that after the lower back assembly deflects forwards or backwards, the supporting and adjusting assembly supports the lower back assembly to stay at a corresponding position.

In order to enable the chair back component to have the function of adjusting the seat depth, the back support component is split into an upper back component and a lower back component, and the lower back component realizes the function; when the lower back component rotates, the lower part of the lower back component deflects forwards and is supported by the supporting and adjusting component, so that the adjustment of the seat depth is really realized; and the range of seat depth adjustment depends on the length of back of the body subassembly and the stroke that supports adjusting part down, compares the adjustment mechanism behind the single back of the body frame screen cloth, and the mechanism control range of this scheme is bigger, need not the switch, easy operation.

Preferably, the back support is a substantially L-shaped plate-shaped body, and comprises a vertical plate and a horizontal plate, and the horizontal plate is used for connecting the seat; the upper part of the lower back component is provided with a first connecting lug, the upper part of the vertical plate is provided with a rotating seat, and the rotating connecting lug is rotatably connected with the rotating seat through a rotating shaft; the lower back of the body subassembly lower part is equipped with the second engaging lug, the one end rotation of supporting adjusting part is connected in the riser lower part, and the other end and the second engaging lug of supporting adjusting part rotate to be connected. When the lower back assembly rotates, the support adjusting assembly and the back bracket and the lower back assembly also rotate relatively, so that the support adjusting assembly and the back bracket need to be connected with the lower back assembly in a rotating way.

Preferably, the upper back component is arranged at the upper end of the vertical plate; when the lower back component deflects forwards, the included angle between the lower back component and the upper back component is reduced, and the lower back component is supported by the support adjusting component and is kept at the position opposite to the upper back component; when the lower back component deflects backwards, the included angle between the lower back component and the upper back component is enlarged, and the lower back component is supported by the supporting and adjusting component to be kept at the position opposite to the upper back component. The contained angle between back of the body subassembly and the last back of the body subassembly has reacted the lifting and the decline of back of the body subassembly down, and back of the body subassembly can not only adjust the seat depth down promptly, can adjust the height of pushing up the waist moreover, adapts to different rising crowds.

Preferably, the supporting and adjusting assembly can be any one of an electric push rod, an air rod or a hydraulic rod, two ends of the supporting and adjusting assembly are respectively connected with the back support and the lower back assembly in a rotating manner, and the inclination angle of the supporting and adjusting assembly relative to the horizontal plane changes along with the deflection motion of the lower back assembly. The common and universal accessories such as the electric push rod, the air rod or the hydraulic cylinder are used as the supporting and adjusting component, so that the development cost is saved, and the function of the supporting and adjusting component can be realized.

Preferably, the supporting and adjusting assembly is inclined upwards between the back support and the back support piece from back to front, and when the lower end of the back support piece moves forwards, the included angle between the whole supporting and adjusting assembly and the horizontal plane is reduced.

Preferably, a space is always reserved between the lower end of the back support and the back support, the width of the back support is larger than that of the back support, and the support adjusting assembly is arranged at the middle position in the width direction of the back support.

Preferably, the support adjusting assembly comprises a first support seat and a second support seat, and the first support seat and the second support seat generate relative movement when the lower back assembly rotates; the clamping mechanism is arranged between the first supporting seat and the second supporting seat, the clamping mechanism is configured to keep the position of the first supporting seat after the first supporting seat and the second supporting seat move relatively when the lower back component rotates forwards, the clamping mechanism comprises a rack, a clamping tongue and a spring, a plurality of clamping grooves are distributed on the rack along the length direction, and the clamping tongue rotates around a pivot and keeps the trend of being clamped with the clamping grooves under the action of the spring. Supporting and holding the lower back assembly in the corresponding position is achieved.

Preferably, the clamping mechanism further comprises a tongue seat and a limiting piece, the clamping tongue is connected to the tongue seat, and the tongue seat is connected with the pivot; the rack comprises a clamping tooth section, a plurality of clamping teeth are distributed on the clamping tooth section along the length direction, and a clamping groove is formed between every two clamping teeth; along the length direction, the two ends of the rack at the clamping tooth section are respectively provided with a clamping tongue jacking and holding section and a rotary boss; along the thickness direction of the rack, the heights of the clamping tongue jacking and holding section and the rotary boss are both greater than the height of the clamping tooth section; the tongue base is also provided with a locking tongue matched with the limiting piece, when the clamping tongue is positioned at the clamping tooth section, the clamping tongue is in clamping fit with the clamping groove at the corresponding position, and the limiting piece does not limit the locking tongue; when the clamping tongue abuts against the clamping tongue jacking and maintaining section, the clamping tongue rotates towards the direction leaving the clamping groove, the limiting piece locks the locking tongue and enables the clamping tongue to maintain the unlocking state of being disengaged from the clamping groove, and when the first supporting seat and the second supporting seat move relatively, the limiting piece crosses over the clamping tooth section and touches the rotary boss, so that the clamping tongue rotates reversely to be clamped with the clamping groove, and the locking tongue is disengaged from the limiting piece. The clamping tongue is matched with the clamping groove at the corresponding position, and at the moment, the lower back component can continue to rotate forwards but cannot rotate backwards, so that the support of the support adjusting mechanism to the back support piece is realized; after the first supporting seat and the second supporting seat move relatively, the clamping tongue can be clamped with different clamping grooves, so that the lower back assembly is supported and kept at a corresponding position by the supporting and adjusting mechanism; the clamping tongue jacks up the retaining section to enable the clamping tongue to rotate excessively, and the limiting piece can lock the locking tongue, so that the lower back assembly can rotate backwards but cannot support; the rotary boss can unlock the locked clamping tongue so as to be clamped with the clamping groove again and recover the support of the support adjusting mechanism to the back support piece; the structure is ingenious.

Preferably, the height of the clamping tongue jacking and holding section in the thickness direction of the rack is lower than that of the rotary boss. The arrangement is used for preventing the clamping tongue from directly crossing the rotary boss after being jacked and locked, so that the rotary boss is invalid.

Preferably, the locking tongue and the limiting part are staggered all the time, and when the locking tongue rotates, the locking tongue goes over the limiting part through elastic deformation and is abutted to the limiting part to be locked or is separated from the limiting part to be unlocked. The locking mode is simple and effective, an independent mechanism is not needed for locking the clamping tongue, the tongue seat and the locking tongue, and cost and assembly time are saved.

Preferably, at least one of the limiting member and the locking tongue is an elastic member.

Preferably, the first support seat is a hollow sleeve, and the rack is fixedly arranged in the first support seat; the clamping tongue, the tongue seat, the spring and the limiting piece are arranged on the second supporting seat, and the first supporting seat is in sleeve fit with the second supporting seat; the second supporting seat is rotatably connected with the back support, and the first supporting seat is rotatably connected with the lower back component. When the lower back component rotates, the first and second supporting seats move relatively, and the first and second supporting seats are respectively connected with the back supporting piece and the back support in a rotating way.

Preferably, the spring is a torsion spring, the tongue base is rotatably connected with the second support base through a pivot, the torsion spring is sleeved on the pivot, the first torsion arm and the second support base of the torsion spring are kept relatively fixed, and the second torsion arm of the torsion spring acts on the tongue base. The torsion spring is used for returning the clamping tongue, so that the clamping tongue can be clamped with the corresponding clamping groove all the time after the first supporting seat and the second supporting seat move relatively.

Preferably, the limiting member is a plate-shaped body which is fixedly mounted on the second supporting body, and one end of the limiting member is suspended to form a limiting part matched with the locking tongue. When the limiting part locks the clamping tongue, the limiting part props against the locking tongue to resist the elasticity of the torsion spring.

The design starting point, the idea and the beneficial effects of the utility model adopting the technical scheme are as follows:

the utility model provides a chair back component with adjustable seat depth, compared with the prior art:

1. the chair back component divides the back supporting piece into an upper back component and a lower back component, and the lower back component is rotatably connected to the back bracket and supported by the supporting and adjusting component to stay at a corresponding position after rotation; because the rotation connecting point is positioned at the upper part of the lower back component, the lower back component can deflect forwards or backwards when rotating, and the functions of supporting the waist and adjusting the seat depth are realized.

2. Because the rotation connecting point is positioned at the upper part of the lower back component, the lower back component deflects towards the front upper part or the rear lower part when moving, the height of the top waist can be adjusted while the seat depth is adjusted, so that the chair is suitable for people with different rising heights.

2. The upper back component and the lower back component are independent, the upper back component and the back support can be integrally formed, the lower back component and the back support only need to be rotatably connected, the cost is reduced, and the assembly process is simplified.

3. The support adjusting mechanism is close to a human body, the adjustment is convenient, when an air rod, an electric push rod or a hydraulic rod is used, only a button needs to be pressed, and a bolt does not need to be screwed; when the support adjusting mechanism comprising the first supporting seat and the second supporting seat is adopted, the switch is not needed, and only the lower back component needs to be pulled to carry out the waist and back support adjustment, because the support adjusting mechanism has the self-locking capacity.

4. The supporting and adjusting assembly is inclined upwards between the back support and the lower back assembly from back to front, and when the lower end of the lower back assembly moves forwards, the included angle between the whole supporting and adjusting assembly and the horizontal plane is reduced; the effective supporting force of the supporting and adjusting assembly to the lower back assembly is larger, and the structure is more stable.

5. When the open type chair back combined by the back support and the back support piece is used, even though the air rod or the electric push rod is used for realizing the jacking or falling of the lower back component, the appearance is monotonous and is not aesthetic when the air rod or the electric push rod is exposed outside due to the fixed shape; in order to solve the problems, the support adjusting assembly is in a sleeved mode, the first supporting seat and the second supporting seat are fixed in a clamping mode, the outer shapes of the first supporting seat and the second supporting seat can be adjusted correspondingly according to the overall style of the seat, and therefore the attractiveness is improved, for example, the seat is designed to be in a cuboid shape or patterns are added on the appearance of the seat.

6. The support adjustment assembly of the present invention is used with a shorter initial length and smaller volume than a gas stick for the same stroke.

Drawings

FIG. 1 is a schematic perspective view of a combination of a back support, a back support and a support adjustment assembly according to an embodiment of the present invention;

FIG. 2 is a side view of an embodiment of the present invention with the lower back assembly and the support adjustment assembly adjusted;

FIG. 3 is a perspective view of a lower back assembly attached to a back support in an embodiment of the present invention;

FIG. 4 is a perspective view of the lower back assembly rotated on the back bracket in an embodiment of the present invention;

FIG. 5 is a perspective view of a lower back assembly attached to a back support in an embodiment of the present invention;

FIG. 6 is a schematic perspective view of a support adjustment assembly according to an embodiment of the present invention;

FIG. 7 is a schematic perspective view of the embodiment of the present invention illustrating the engagement between the latch and the slot;

FIG. 8 is a cross-sectional view of the support adjustment assembly with the latch tongue in the primary slot in an embodiment of the present invention;

FIG. 9 is an enlarged view of portion B of FIG. 8;

FIG. 10 is a cross-sectional view of the support adjustment assembly with the latch engaging the slot in an embodiment of the present invention;

FIG. 11 is an enlarged view of portion C of FIG. 10;

FIG. 12 is a cross-sectional view of the support adjustment assembly after the locking tongue is locked by the limiting portion in an embodiment of the utility model;

FIG. 13 is an enlarged view of portion D of FIG. 12;

FIG. 14 is a cross-sectional view of a support adjustment assembly with the latch being set back by a surface of revolution in an embodiment of the utility model;

FIG. 15 is an enlarged view of section E of FIG. 14;

FIG. 16 is an exploded view of a first support adjustment assembly in an embodiment of the present invention;

FIG. 17 is an exploded view of a second support adjustment assembly in an embodiment of the present invention;

FIG. 18 is a first perspective view illustrating a rack and a second support base according to an embodiment of the present invention;

fig. 19 is a second schematic perspective view illustrating a rack and a second support seat according to an embodiment of the present invention.

The figures are numbered: a back support 1; a vertical plate 11; a transverse plate 12; a rotating base 13; a back support 2; an upper back assembly 21; a lower back assembly 22; a first connection lug 221; a second engaging lug 222; a support adjustment assembly 101; a first support 102; a second support seat 103; a rack 104; a latch tongue 105; a card slot 106; a pivot 107; a torsion spring 108; a latch section 109; a latch 110; a self-locking face 111; a sliding surface 112; a tongue base 113; a locking tongue 114; an elastic sheet 115; a stopper portion 116; a latch jack-up retention section 117; a swivel boss 118; a jacking surface 119; a last stage card slot 120; a surface of revolution 121; a primary card slot 122; a first torsion arm 123; second torque arm 124.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the utility model will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, the term "at least one" means one or more than one unless explicitly defined otherwise. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The specific embodiment of the utility model is as follows:

most of chairs for adjusting lumbar support in the market rely on the addition of a separate lumbar support part on the chair back to carry out lumbar support and adjustment, but the chairs have the problems of abrupt appearance, poor comfort due to the fact that the chair only supports one part of the waist, short adjustment stroke of the lumbar support part and the like; therefore, the chair back needs to be adjustable in seat depth to support the waist, and also needs to be beautiful and comfortable and have a wide adjusting range.

As shown in fig. 1 and 2, the present invention provides a chair back assembly with adjustable seat depth, which comprises a back support 1, a back support 2 and a support adjusting assembly 101.

The back support 1 is configured to support the body of the back support 2, and the back support 2 is configured to support the waist and back of a human body; the back support 2 comprises an upper back component 21 and a lower back component 22 which are separated up and down, the upper back component 21 is arranged on the back support 1, the upper part of the lower back component 22 is rotatably connected on the back support 1, the lower back component 22 is positioned below the upper back component 21, and back cushions or mesh cloth can be coated on the front sides of the upper back component 21 and the lower back component 22; the lower part of the upper back component 21 is connected with the upper part of the back bracket 1, and the upper back component 21 and the back bracket 1 can be integrally formed; because the rotating connection point of the lower back component 22 and the back bracket 1 is positioned at the upper part of the lower back component 22, when the lower back component 22 rotates, the lower end of the lower back component 22 deflects forwards or backwards, thereby adjusting the seat depth; the supporting and adjusting assembly 101 is disposed between the back support 1 and the lower back assembly 22 and the supporting and adjusting assembly 101 is connected to the lower portion of the back support 1, and is configured such that the supporting and adjusting assembly 101 stays at a corresponding position after the lower back assembly 22 is deflected forward or backward.

As shown in fig. 3-5, the back support 1 is a substantially L-shaped plate, and includes a vertical plate 11 for connecting a chair back assembly and a horizontal plate 12 for connecting a chair seat, the upper back assembly 21 is disposed on the upper end of the vertical plate 11, and the lower back assembly 22 is rotatably connected to the upper portion of the vertical plate 11; the upper part of the lower back component 22 is provided with two first connecting lugs 221 which are arranged at intervals, the upper part of the vertical plate 11 is provided with a rotating seat 13 which protrudes forwards, and when the lower back component 22 is installed with the back support 1, the rotating seat 13 enters between the two first connecting lugs 221 and is rotatably connected through a rotating shaft; the lower part of the lower back component 22 is provided with two second engaging lugs 222 which are arranged at intervals, one end of the supporting and adjusting component 101 is rotatably connected to the lower part of the vertical plate 11, and the other end of the supporting and adjusting component 101 enters between the two second engaging lugs 222 and is rotatably connected through a rotating shaft.

Because the rotation connection point of the lower back assembly 22 and the back support 1 is located at the upper part of the lower back assembly 22, the motion track of the lower back assembly 22 actually deflects forwards and upwards or backwards and downwards, the deflection of the lower back assembly 22 in the front and back direction can be used for adjusting the seat depth, and the deflection in the up and down direction can be used for adjusting the waist supporting height, so that the seat depth adjustment is realized, and the waist height of different rising crowds can be adapted.

The lower back assembly 22 can rotate relative to the back support 1, and then the support adjusting assembly 101 supports and keeps the lower back assembly 22 at a corresponding position after rotating, so that the adjustment of the lumbar support height and the seat depth can be realized; from back to front, support adjusting part 101 and be the slope of slant between back of the body support 1 and back of the body support piece 2, because the both ends that support adjusting part 101 respectively with back of the body support 1, lower back of the body subassembly 22 rotates and is connected, when back of the body subassembly 22 rotates for back of the body support 1, support adjusting part 101 along with to the inclination of horizontal plane changes, and when back of the body subassembly 22 deflects forward, support adjusting part 101 and reduce for the contained angle of horizontal plane, thereby make the effective holding power that supports adjusting part 101 to back of the body subassembly 22 down bigger, the structure is more firm.

Since the electric push rod, the air rod and the hydraulic cylinder are all common, the case that the supporting and adjusting assembly 101 is an electric push rod, an air rod or a hydraulic rod is not illustrated in detail in this embodiment; in order to make the supporting and adjusting assembly 101 have a strong supporting force without on-off control, the supporting and adjusting assembly 101 is designed as follows:

as shown in fig. 2 and 6-19, the supporting and adjusting assembly 101 includes a first supporting seat 102 rotatably connected to the lower back assembly 22 and a second supporting seat 103 rotatably connected to the back frame 1, wherein the first supporting seat 102 and the second supporting seat 103 move relatively when the lower back assembly 22 rotates; the first supporting seat 102 is a hollow sleeve, the first supporting seat 102 is sleeved on the second supporting seat 103, and the supporting and adjusting assembly 101 moves in a telescopic manner when the lower back assembly 22 rotates; a clamping mechanism is arranged between the first supporting seat 102 and the second supporting seat 103, the clamping mechanism is configured to keep the positions of the first supporting seat 102 and the second supporting seat 103 after relative movement when the back supporting member 2 is opened forwards, the clamping mechanism comprises a rack 104, a clamping tongue 105 and a spring, a plurality of clamping grooves 106 are distributed on the rack 104 along the length direction, and the clamping tongue 105 rotates around a pivot 107 and keeps the trend of clamping with the clamping grooves 106 under the action of the spring; the spring is a torsion spring 108; the latch mechanism mainly functions to enable the support adjustment assembly 101 to have a self-locking capability for supporting the lower back assembly 22 when the lower back assembly 22 leans back on the lower back assembly 22, but the latch mechanism does not have a self-locking capability for the support adjustment assembly 101 when the lower back assembly 22 deflects forward.

The rack 104 is installed in the first support seat 102 and comprises a latch section 109, a plurality of latches 110 are distributed on the latch section 109 along the length direction, a slot 106 is formed between every two latches 110, the latches 110 are right-angled trapezoidal, each latch 110 comprises a sliding surface 112 and a self-locking surface 111 perpendicular to the relative movement direction of the first support seat and the second support seat, the sliding surface 112 on the same latch 110 is inclined relative to the self-locking surface 111, an included angle between the two is an acute angle, and the sliding surface 112 is closer to the lower back component 22 relative to the self-locking surface 111; the latch 105 is in a triangular prism shape and comprises a tip 129, the tip 129 of the latch 105 is clamped in the slot 106 and is in clamping fit with the slot 106, when the waist and back leans back on the lower back assembly 22, the supporting and adjusting assembly 101 has a contraction tendency, that is, the first supporting seat 102 has a tendency of moving backwards relative to the second supporting seat 103, at the moment, the self-locking surface 111 abuts against the tip 129 of the latch 105, and the latch 105 prevents the first supporting seat 103 from moving backwards, that is, self-locking of the supporting and adjusting assembly 101 during contraction is completed; when the lower back assembly 22 is pulled to open by one stage, the supporting and adjusting assembly 101 extends by one stage, that is, the first supporting seat 102 moves forward by one stage relative to the second supporting seat 103, and in the process, the sliding surface 112 slides relative to the latch 105 until the latch 105 is latched into the next latch groove 106; each stage of the lower back assembly 22 opening corresponds to one card slot 106.

The clamping mechanism further comprises a tongue seat 113 and a limiting piece, the clamping tongue 105 is connected to the tongue seat 113, the tongue seat 113 is sleeved on the pivot 107, the tongue seat 113, the clamping tongue 105 and the torsion spring 108 are arranged on the second support seat 103, the torsion spring 108 is sleeved on the pivot 107, the first torsion arm 123 of the torsion spring 108 and the second support seat 103 are kept relatively fixed, and the second torsion arm 124 of the torsion spring 108 acts on the tongue seat 113, so that the tongue seat 113 can be restored to an initial position after rotating around the pivot 107; the tongue base 113 is also provided with a locking tongue 114 matched with the limiting piece, the locking tongue 114, the tongue base 113 and the clamping tongue 105 are integrally formed, and an included angle of 130 degrees is formed between the locking tongue 114 and the clamping tongue 105; the limiting member is a plate-shaped elastic sheet 115 fixed on the second support body, the elastic sheet 115 and the locking tongue 114 are always staggered, and one end of the elastic sheet 115 is suspended to form a limiting part 116 matched with the locking tongue 114.

Along the length direction, the rack 104 is respectively provided with a clamping tongue jacking and holding section 117 and a rotary boss 118 at two ends of the clamping tooth section 109; along the thickness direction of the rack 104, the heights of the clamping tongue jacking and holding section 117 and the rotary boss 118 are both greater than the height of the clamping tooth section 109, and the height of the rotary boss 118 is greater than the height of the clamping tongue jacking and holding section 117; the latch jacking and holding section 117 comprises a jacking surface 119 parallel to the sliding surface 112, and a final clamping groove 120 is formed between the jacking surface 119 and the last clamping tooth of the clamping tooth section 109; the rotary boss 118 comprises a rotary surface 121 parallel to the self-locking surface 111, and a primary clamping groove 122 is formed between the rotary surface 121 and the first clamping tooth of the clamping tooth section 109; when the latch tongue 105 is located on the latch section 109, the latch tongue 105 is in clamping fit with the corresponding position of the latch groove 106, and the limiting part 116 of the elastic sheet 115 does not limit the locking tongue 114; when the tip 129 of the latch tongue 105 relatively moves backwards from the last-stage card slot 120, the tip 129 abuts against the jacking surface 119 of the latch tongue jacking and holding section 117 to enable the latch tongue 105 to rotate towards the direction away from the card slot 106, the locking tongue 114 rotates along with the latch tongue 105, passes over the limiting part 116 of the elastic sheet 115 and abuts against the limiting part 116 to be locked, and the latch tongue 105 is enabled to keep the unlocking state of being disengaged from the card slot 106; at this time, the tip 129 of the latch 105 crosses over the latch section 109 when the support adjusting assembly 101 contracts, the tip 129 of the latch 105 touches the revolution surface 121 of the revolution boss 118, the latch 105 is urged to rotate reversely to be latched with the primary latch groove 122, and the locking latch 114 also rotates reversely to pass through the elastic piece 115 and disengage from the limiting part 116 of the elastic piece 115.

The supporting and adjusting mechanism is close to a human body, and is convenient to adjust, and the waist and back supporting and adjusting can be carried out only by pulling the lower back component 22 because the supporting and adjusting mechanism has the self-locking capability in the contraction direction and has no self-locking in the extension direction.

As shown in fig. 3 and 4, a space is always left between the lower end of the lower back assembly 22 and the back support 1, the width of the back support 2 is larger than that of the back support 1, and the support adjusting assembly 101 is arranged at the middle position along the width direction of the back support 2, so that the appearance is beautiful and unobtrusive, and the user can lean more comfortably.

Claims (14)

1. A seat back assembly with adjustable seat depth, comprising:

a back bracket configured to support a body of the back support;

a back support configured to support a human lumbar back; the back support comprises an upper back component and a lower back component which are separated up and down, the upper back component is arranged on the back support, and the upper part of the lower back component is rotatably connected on the back support;

and the supporting and adjusting assembly is arranged between the back support and the lower back assembly and is connected to the lower part of the back support, and the supporting and adjusting assembly is configured in such a way that after the lower back assembly deflects forwards or backwards, the supporting and adjusting assembly supports the lower back assembly to stay at a corresponding position.

2. The adjustable seat depth seatback assembly of claim 1, wherein: the back support is a plate-shaped body which is approximately L-shaped and comprises a vertical plate and a transverse plate, and the transverse plate is used for connecting the chair seat; the upper part of the lower back component is provided with a first connecting lug, the upper part of the vertical plate is provided with a rotating seat, and the rotating connecting lug is rotatably connected with the rotating seat through a rotating shaft; the lower back of the body subassembly lower part is equipped with the second engaging lug, the one end rotation of supporting adjusting part is connected in the riser lower part, and the other end and the second engaging lug of supporting adjusting part rotate to be connected.

3. The adjustable seat depth seatback assembly of claim 2, wherein: the upper back component is arranged at the upper end of the vertical plate; when the lower back component deflects forwards, the included angle between the lower back component and the upper back component is reduced, and the lower back component is supported by the support adjusting component and is kept at the position opposite to the upper back component; when the lower back component deflects backwards, the included angle between the lower back component and the upper back component is enlarged, and the lower back component is supported by the supporting and adjusting component to be kept at the position opposite to the upper back component.

4. The adjustable seat depth seatback assembly of claim 1, wherein: the support adjusting component can be any one of an electric push rod, an air rod or a hydraulic rod, two ends of the support adjusting component are respectively connected with the back support and the lower back component in a rotating mode, and the inclination angle of the support adjusting component relative to the horizontal plane changes along with the deflection motion of the lower back component.

5. The adjustable seat depth seatback assembly of claim 1, wherein: from back to front, support the adjusting part and be the slope of ramp up between back of the body support piece and back support piece, when back support piece lower extreme moved forward, support the whole contained angle with the horizontal plane of adjusting part and diminish.

6. The adjustable seat depth seatback assembly of claim 1, wherein: the interval is always left between the lower end of the back support piece and the back support, the width of the back support piece is larger than that of the back support, and the support adjusting component is arranged at the middle position in the width direction of the back support piece.

7. The adjustable seat depth seatback assembly of claim 1, wherein: the support adjusting assembly comprises a first support seat and a second support seat, and the first support seat and the second support seat generate relative movement when the lower back assembly rotates; the clamping mechanism is arranged between the first supporting seat and the second supporting seat, the clamping mechanism is configured to keep the position of the first supporting seat after the first supporting seat and the second supporting seat move relatively when the lower back component rotates forwards, the clamping mechanism comprises a rack, a clamping tongue and a spring, a plurality of clamping grooves are distributed on the rack along the length direction, and the clamping tongue rotates around a pivot and keeps the trend of being clamped with the clamping grooves under the action of the spring.

8. The adjustable seat depth seatback assembly of claim 6, wherein: the clamping mechanism also comprises a tongue seat and a limiting piece, the clamping tongue is connected on the tongue seat, and the tongue seat is connected with the pivot; the rack comprises a clamping tooth section, a plurality of clamping teeth are distributed on the clamping tooth section along the length direction, and a clamping groove is formed between every two clamping teeth; along the length direction, the two ends of the rack at the clamping tooth section are respectively provided with a clamping tongue jacking and holding section and a rotary boss; along the thickness direction of the rack, the heights of the clamping tongue jacking and holding section and the rotary boss are both greater than the height of the clamping tooth section; the tongue base is also provided with a locking tongue matched with the limiting piece, when the clamping tongue is positioned at the clamping tooth section, the clamping tongue is in clamping fit with the clamping groove at the corresponding position, and the limiting piece does not limit the locking tongue; when the clamping tongue abuts against the clamping tongue jacking and maintaining section, the clamping tongue rotates towards the direction leaving the clamping groove, the limiting piece locks the locking tongue and enables the clamping tongue to maintain the unlocking state of being disengaged from the clamping groove, and when the first supporting seat and the second supporting seat move relatively, the limiting piece crosses over the clamping tooth section and touches the rotary boss, so that the clamping tongue rotates reversely to be clamped with the clamping groove, and the locking tongue is disengaged from the limiting piece.

9. The adjustable seat depth seatback assembly of claim 7, wherein: the height of the clamping tongue jacking and maintaining section along the thickness direction of the rack is lower than that of the rotary boss.

10. The adjustable seat depth seatback assembly of claim 7, wherein: the locking tongue and the limiting part are staggered all the time, and when the locking tongue rotates, the locking tongue crosses the limiting part through elastic deformation and is abutted with the limiting part to be locked or is separated from the limiting part to be unlocked.

11. The adjustable seat depth seatback assembly of claim 9, wherein: at least one of the limiting piece and the locking tongue is an elastic piece.

12. The adjustable seat depth seatback assembly of claim 7, wherein: the first support seat is a hollow sleeve, and the rack is fixedly arranged in the first support seat; the clamping tongue, the tongue seat, the spring and the limiting piece are arranged on the second supporting seat, and the first supporting seat is in sleeve fit with the second supporting seat; the second supporting seat is rotatably connected with the back support, and the first supporting seat is rotatably connected with the lower back component.

13. The adjustable seat depth seatback assembly of claim 7, wherein: the spring is a torsion spring, the tongue seat is rotatably connected with the second supporting seat through a pivot, the torsion spring is sleeved on the pivot, the first torsion arm of the torsion spring and the second supporting seat are relatively fixed, and the second torsion arm of the torsion spring acts on the tongue seat.

14. The adjustable seat depth seatback assembly of claim 7, wherein: the limiting piece is a plate-shaped body and is fixedly arranged on the second supporting body, and one end of the limiting piece is suspended to form a limiting part matched with the locking tongue.

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