WO2019242778A1

WO2019242778A1 - Automatically collapsible stroller frame

Info

Publication number: WO2019242778A1
Application number: PCT/CN2019/092602
Authority: WO
Inventors: Shunping YANG
Original assignee: Zhongshan Kingmoon Children Products Co., Ltd.
Priority date: 2018-06-22
Filing date: 2019-06-24
Publication date: 2019-12-26
Also published as: CN108860280B; NL2023365B1; NL2023365A; WO2019242048A1; CN108860280A

Abstract

Automatically collapsible stroller frame, comprising a front leg bar (11), a rear leg bar (21), a handlebar set (3) and an elastic member (7). The handlebar set (3) comprises a lower handlebar tube (31) and an upper handlebar tube (32) that is rotatably disposed at the upper end of the lower handlebar tube (31), the handlebar tube (3) is provided with a sliding member (4) that is slidable along its axial direction, a locking assembly (5) is provided between the lower handlebar tube (31) and the sliding member (4) for locking or unlocking the sliding member (4), the lower end of the lower handlebar tube (31) is hinged to the middle of the rear leg bar (21), a transmission member (6) is hinged between the sliding member and the upper portion of the rear leg bar (21), the upper end of the front leg bar (11) is hinged to the lower end of the transmission member (6) and/or the upper end of the rear leg bar (21), and an elastic member (7) is disposed between the front leg bar (11) and the rear leg bar (21). When the stroller collapses, the front leg bar (11) and the rear leg bar (21) are automatically brought together under the elastic pull of the elastic member (7). At the same time, the transmission member (6) drives the sliding member (4) to slide down the axial direction of the lower handlebar tube (31) to drive the lower handlebar tube (31) towards the direction of the rear leg bar (21), thereby collapsing the whole stroller frame, which is very fast and convenient.

Description

Automatically collapsible stroller frame

Technical Field

The present invention relates to the field of strollers, in particular to an automatically collapsible stroller frame.

Background Art

The stroller is a functional carriage designed to facilitate children's outdoor activities, greatly reducing the burden of carrying children when going out. In order to facilitate carrying and transportation, conventional strollers are generally foldable to reduce space occupation. However, most conventional strollers need to be collapsed manually, and the collapsing operation is rather complicated.

CN205971433 discloses a stroller which is to be manually folded and unfolded. This is quite difficult, especially for a mother who at the same time carries a toddler on one arm and only has one free hand to fold or unfold the stroller. The stroller comprises two sliders which need to be hand-operated.

Furthermore in the collapsed state the stroller of CN205971433 can only lie flat on the ground. It is not capable of standing upright. It is in particular not capable of remaining upright during the folding operation. This makes the stroller of CN205971433 cumbersome in operation, especially for a mother holding her child in one arm.

CN205168603U discloses another stroller. This stroller has a handlebar tube which disconnects from the rear leg bar, see in particular figure 9 of CN205168603U. This is very complex and cumbersome for a user. The folding operation is also very different because the upper handlebar tube rotates to the rear and the hinge between the upper handlebar tube and the lower handlebar tube, indicated with 14 in fig. 4 of CN205168603U, does not move toward the rear leg, but stays at the opposite side of the collapsed stroller frame. It was recognized in the present invention that these features make it difficult to maintain the balance of the stroller frame during the collapsing and therefore make it difficult to ensure that the stroller frame stays upright both during and after the collapsing operation.

Summary of the Present Invention

The technical problem to be solved by the present invention is to provide an automatically collapsible stroller frame to make the collapsing operation more convenient and faster.

The object of the present invention is achieved by:

an automatically collapsible stroller frame, comprising:

a front leg set, the front leg set comprising a front leg bar;

a rear leg set, the rear leg set comprising a rear leg bar;

a handlebar set, the handlebar set comprising a lower handlebar tube and a U-shaped upper handlebar tube that is rotatably disposed at an upper end of the lower handlebar tube, the lower handlebar tube being provided with a sliding member that is slidable along its axial direction, a locking assembly being disposed between the lower handlebar tube and the sliding member for locking or unlocking the sliding member to be fixed on the lower handlebar tube or to slide in the axial direction of the lower handlebar tube, the lower end of the lower handlebar tube being hinged to the middle portion of the rear leg bar, a transmission member being hinged between the sliding member and the upper portion of the rear leg bar, and the upper end of the front leg bar being hinged to the lower end of the transmission member and/or the upper end of the rear leg bar; and

an elastic member, the elastic member being associated with the front leg bar and the rear leg, in particular disposed between the front leg bar and the rear leg bar such that when the stroller frame collapses, the front leg bar and the rear leg bar are automatically brought close together under the elastic pulling of the elastic member, thereby completing automatic collapsing.

With the above-mentioned configuration, when the upper handlebar tube is rotated and folded relative to the lower handlebar tube, the locking assembly unlocks the sliding member, and the front leg bar and the rear leg bar automatically close together under the elastic pulling of the elastic member. At the same time, the transmission member drives the sliding member to slide down the axial direction of the lower handlebar tube to drive the lower handlebar tube towards the direction of the rear leg bar, thereby collapsing the whole stroller frame, which is very fast and convenient.

The present invention provides an automatically collapsible stroller frame as described above, further comprising a seat set, the front portion of the seat set being hinged to the middle of the front leg bar. The rear end of the seat set may be hinged to the lower end of the lower handlebar tube, in particular via a connecting base. The front end of the elastic member may be fixed to the front portion of the seat set, in particular fixed to a front portion or to a middle portion of the seat set. The elastic member may act between the front portion of the seat set and the rear leg bar. When the stroller collapses, the front leg bar and the rear leg bar are automatically brought together, and the seat set is also rotated forward to move towards the front leg bar.

The present invention provides an automatically collapsible stroller frame as described above, further comprising a backrest set, the backrest set comprising a U-shaped backrest bar, a connecting base being connected to the lower end of the lower handlebar tube which is hinged to the middle portion of the rear leg bar.

In an embodiment, the end of the backrest bar is hinged to the connecting base, and the rear end of the elastic member is directly or indirectly fixed to the connecting base or directly fixed to the rear leg bar. When the stroller collapses, the front leg bar and the rear leg bar are automatically brought together, driving the connecting base and the backrest bar to, following the lower handlebar tube, move towards the rear leg bar.

The present invention provides an automatically collapsible stroller frame as described above, wherein the locking assembly comprises a locking pin disposed in the lower handlebar tube and a locking hole disposed in the sliding member, and the locking pin can penetrate the lower handlebar tube and be elastically engaged in the locking hole. When the locking assembly is in the locked state, the locking pin in the lower handlebar tube is engaged in the locking hole of the sliding member so that the sliding member is not slidable relative to the lower handlebar tube. In this case, the stroller frame is not collapsible from an unfolded state to a folded state, and thus the stroller frame does not unexpectedly collapse and injure the baby when the stroller is used. When the locking assembly is in the unlocked state, the locking pin is disengaged from the locking hole, and the sliding member is slidable along the axial direction of the lower handlebar tube. In this case, the stroller frame is collapsible from an unfolded state to a folded state. In addition, the locking assembly of the present invention has a simple structure and operates reliably.

The present invention provides an automatically collapsible stroller frame as described above, wherein a rotating base is disposed between the lower handlebar tube and the upper handlebar tube, and a linkage member, in particular a pull cord, is disposed between the rotating base and the locking pin. To fold the stroller frame, it is only necessary to rotate the upper handlebar tube so that it rotates relative to the lower handle bar tube and is folded. In this case, the rotating base rotates at the same time, thereby driving the pull cord to move, and thereby causing the locking pin to be disengaged from the locking hole. In this case, the locking assembly is in the unlocked state, and the stroller frame is automatically collapsible from an unfolded state to a folded state. When it is necessary to unfold the stroller frame, first unfold the other parts of the stroller frame in turn, and then rotate the upper handlebar tube in the opposite direction, and the rotating seat rotates at the same time. The locking pin is reset by the elastic force and inserted into the locking hole, so that the locking assembly is locked when the stroller frame is in an unfolded state.

The present invention provides an automatically collapsible stroller frame as described above, wherein the upper handlebar tube is provided with an unlocking member for unlocking or locking the upper handlebar tube so that it is rotatable or fixable relative to the lower handlebar tube. To fold the stroller frame, it is only necessary to operate the unlocking member so that the upper handlebar tube is unlocked and operate it to rotate relative to the lower handlebar tube and fold, thereby realizing automatic collapsing. When the stroller frame is unfolded, the unlocking member locks the upper handlebar tube so that it is not rotatable relative to the lower handlebar tube.

In an embodiment of the automatically collapsible stroller frame as described above, the upper end of the front leg bar, the lower end of the transmission member, and the upper end of the rear leg bar are coaxially hinged.

In another embodiment of the automatically collapsible stroller frame as described above, the upper end of the front leg bar is hinged to the upper end of the rear leg bar and is not hinged to the lower end of the transmission member.

In yet another embodiment of the automatically collapsible stroller frame as described above, the upper end of the front leg bar is hinged to the lower end of the transmission member and is not hinged to the upper end of the rear leg bar.

In an embodiment, the U-shaped upper handlebar tube is configured to rotate in a forward direction relative to the lower handlebar tube. This ensures that gravity will pull the upper handlebar tube to its end position which is not the case if the upper handlebar tube rotates to the rear. The upper handlebar tube is in particular configured to rotate forward over an angle of more than 150 degrees, in order to collapse the automatically collapsible stroller frame.

In an embodiment, in the collapsed state the automatically collapsible stroller frame can stand in an upright orientation. This feature is a significant advantage over other strollers, which can only lie flat on the ground.

In an embodiment, in the collapsed state the stroller frame can stand on its four wheels, wherein the front leg bar and the rear leg bar extend in an essentially upward direction, more in particular an upright direction, from respectively the front leg wheel and the rear leg wheel when the front leg wheel and the rear leg wheel are in contact with the ground. The relative positions of the four wheels and the positions of the four wheels relative to the centre of gravity make this possible.

In an embodiment, when seen in side view during and after the collapsing movement the centre of gravity of the automatically collapsible stroller frame stays substantially between the front leg wheel and the rear leg wheel, allowing the automatically collapsible stroller frame to collapse to the folded state while staying upright and to remain in the upright position after reaching the collapsed state. This is due to the collapsing movement. The centre of gravity is between and above the front and rear wheels.

In an alternative embodiment, the rotating base contacts the ground or is very close to the ground and in this way provides an additional point of support. In this embodiment the centre of gravity can remain between the front leg wheel and the rotating base, in particular between the rear leg wheel and the rotating base, when seen in side view.

In an embodiment, during the collapsing the front wheels and the rear wheels stay in contact with the ground and the automatically collapsible stroller frame stays upright.

In an embodiment, in the collapsed state in side view a first distance between the front wheel axis and the connecting base is the same or substantially the same as a second distance between the rear wheel axis and the connecting base. This feature advantageously creates the stable upright position of the stroller in the collapsed state and allows the collapsed stroller to stand upright. The first and second distance are measured to the centre of the connecting base when seen in side view.

In an embodiment, the first distance is more than 90 percent and less than 110 percent of the second distance, wherein more in particular the first distance is more than 95 percent and less than 105 percent of the second distance.

In an embodiment, when seen in side view a first distance measured from the first hinge between the front leg bar and the rear leg bar to a rotation axis of the front wheels is at least 90 percent, more in particular at least 95 percent of a second distance measured from the first hinge between the front leg bar and the rear leg bar to a rotation axis of the rear wheels. In an embodiment, in the collapsed state, when seen in side view the rotating base is located at the rear wheels and the U-shaped upper handlebar tube projects in an upward direction from the rotating base.

In an embodiment in the collapsed state, when seen in side view the U-shaped upper handlebar tube is located on an opposite side of the lower handle bar tube as the rear leg bar and is accessible for a user without any obstacles in order to be pulled upward and outward by the user, thereby unfolding the stroller frame. This makes the unfolding operation very easy.

In an embodiment, the sliding member provided on the lower handlebar tube is the only sliding member of the automatically collapsible stroller frame. This makes the stroller frame simple and sturdy.

In an embodiment, there is no sliding member between the lower handlebar tube and the rear leg bar. This makes the stroller frame simple and sturdy.

In an embodiment the stroller frame further comprises a left connector for a left end of a front arm rest and a right connector for a right end of the front arm rest, wherein the left and right connectors are provided at an upper end of the rear leg bar. The front arm rest can extend from left to right in front of the toddler who is sitting in the stroller, thereby providing additional safety.

The left and right connectors may in particular be fixed to the upper end of the rear leg bar. In this way the front arm rest, when present, is also fixed to the rear leg bar. Due to the fixed connection, advantageously, in the collapsed state, the front arm rest extends upwards from the collapsed frame and is very suitable to be used as a handle for carrying the collapsed stroller frame.

In an embodiment the connecting base comprises a protruding section which in the unfolded state protrudes forward and in the folded state protrudes to the rear, and wherein the seat set is connected to this protruding section of the connecting base via a seat hinge.

In an embodiment, a seat hinge where the seat is hinged to the connecting base is located at a distance from a lower handlebar hinge where the lower handlebar tube is connected to the rear leg.

In an embodiment, a length of front leg bar including a caster is substantially the same as length of the rear leg bar, more in particular more than 95 percent of a length of the rear leg bar.

In an embodiment in the collapsed state when seen in side view the front wheel and rear wheel overlap.

In an embodiment when seen in side view in the collapsed state a wheel base axis extends through the front wheel axis and the rear wheel axis and wherein a line extending through the front wheel axis and the connecting member extends at an angle α of more than 75 degrees to the wheel base axis, in particular more than 80 degrees.

In an embodiment when seen in side view in the collapsed state the wheel base axis extends through the front wheel axis and the rear wheel axis and wherein a line extending through the rear wheel axis and the connecting member extends at an angle β of more than 75 degrees to the wheel base axis, in particular more than 80 degrees.

In an embodiment when seen in side view in the collapsed state the wheel base axis extends through the front wheel axis and the rear wheel axis and wherein a line extending through the front wheel axis and the first hinge extends at an angle (γ) of more than 75 degrees to the wheel base axis, in particular more than 80 degrees.

These lines which extend at almost right angles to the wheel base axis ensure that the main parts of the stroller are directly above the wheels, in the collapsed state and when seen in side view. This ensures that the stroller can stand upright.

In a further embodiment the lower handlebar tube may have a length which brings the rotating base close to the ground in the collapsed state. For example, the lower handlebar tube may have a length which positions the rotating base close to the ground, in particular at a distance to the ground of less than 5 cm in the collapsed state, preferably less than 3 cm, more preferably is in contact with the ground when the collapsed stroller frame is in the upright position. Advantageously, a further contact point or a further support point which provides more stability for the collapsed stroller is provided in this embodiment by the rotating base.

The present invention provides an automatically collapsible stroller frame as described above, wherein the elastic member is a spring or a rubber band for providing an elastic pulling force in collapsing the stroller, so that the front leg bar and the rear leg bar are automatically brought close together, thereby completing automatic collapsing.

Brief Description of the Drawings

Specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

Figure 1 is a first structural diagram of the present invention when it is unfolded;

Figure 2 is a second structural diagram of the present invention when it is unfolded;

Figure 3 is a structural view of the present invention when the stroller collapses;

Figure 4 is a structural view of the present invention after collapsing of the stroller;

Figure 5 is a cross-sectional view of the locking assembly of the present invention in the locked state;

Figure 6 is a cross-sectional view of the locking assembly of the present invention in an unlocked state;

Figure 7 is a schematic diagram showing the configuration in which the upper end of the front leg bar, the lower end of the transmission member, and the upper end of the rear leg bar are coaxially hinged;

Figure 8 is a schematic view showing the configuration in which the upper end of the front leg bar is hinged to the upper end of the rear leg bar and is not hinged to the lower end of the transmission member; and

Figure 9 is a schematic view showing the configuration in which the upper end of the front leg bar is hinged to the lower end of the transmission member and is not hinged to the upper end of the rear leg bar.

Specific Embodiments

As shown in Figure 1 to Figure 7, a first embodiment of an automatically collapsible stroller frame of the present invention comprises:

a front leg set 1, the front leg set 1 comprising a front leg bar 11; and

a rear leg set 2, the rear leg set 2 comprising a rear leg bar 21.

The stroller frame comprises a handlebar set 3. The handlebar set 3 is provided with a slider that is slidable along its axial direction. The handlebar set 3 comprises a lower handlebar tube 31 and a U-shaped upper handlebar tube 32 that is rotatably disposed at an upper end of the lower handlebar tube 31, the lower handlebar tube 31 being provided with a sliding member 4 that is slidable along its axial direction.

A locking assembly 5 is provided between the handlebar set 3 and the sliding member 4 for locking or unlocking the sliding member 4. The handlebar set 3 is hinged to the rear leg bar 21, and a transmission member 6 is hinged between the sliding member 4 and the rear leg bar 21 or the front leg bar 11.

In one embodiment, the locking assembly 5 is provided between the lower handlebar tube 31 and the sliding member 4 for locking or unlocking the sliding member 4 so that it is fixed to the lower handlebar tube 31 or is slidable in the axial direction of the lower handlebar tube 31. The lower handlebar tube 31 is hinged to the rear leg bar 21 at lower handlebar hinge 78. For example, the lower end of the lower handlebar tube 31 is hinged to the rear leg bar 21, in particular to a middle portion of the rear leg bar 21 at lower handlebar hinge 78. The lower handlebar hinge 78 is provided on a bracket 79 which projects from the rear of the rear leg 12.

A transmission member 6 is hinged between the sliding member 4 and the upper portion of the rear leg bar 21 or the upper portion of the front leg bar 11. As shown in Figure 7, the upper end of the front leg bar 11, the lower end of the transmission member 6, and the upper end of the rear leg bar 21 are coaxially hinged at the first hinge 66.

The sliding member 4 provided on the lower handlebar tube 31 may be the only sliding member of the automatically collapsible stroller frame. There may be no sliding member between the lower handlebar tube 31 and the rear leg bar 21, only a hinge.

The stroller frame comprises two front wheels 60 and two rear wheels 62. The front wheels 60 rotate about rotation axis 61. The rear wheels 62 rotate about rotation axis 63. The front wheels may be caster wheels which rotate about a (left and right) vertical or substantially vertical rotation axis 64.

A length of front leg bar 11 including the caster 85 is substantially the same as length of the rear leg bar 21, more in particular more than 95 percent of a length of the rear leg bar 21. This improves the stability of the stroller frame when collapsed.

The stroller frame further comprises an elastic member 7, the elastic member 7 being a spring or a rubber band. The elastic member 7 is associated with the front leg bar 11 and the rear leg bar 21, in particular disposed between the front leg bar 11 and the rear leg bar 21, such that when the stroller frame collapses, the front leg bar 11 and the rear leg bar 21 are automatically brought close together under the elastic pulling of the elastic member 7, thereby completing automatic collapsing.

When the upper handlebar tube 32 is rotated relative to the lower handlebar tube 31, the locking assembly 5 unlocks the sliding member 4, and the front leg bar 11 and the rear leg bar 21 are automatically brought close together by the elastic pulling of the elastic member 7. At the same time, the transmission member 6 drives the sliding member 4 to slide down the axial direction of the lower handlebar tube 31 to drive the lower handlebar tube 31 towards the direction of the rear leg bar 21, thereby collapsing the whole stroller frame, which is very fast and convenient.

The stroller frame further comprises a seat set 8, the front portion of the seat set 8 being hinged to the middle of the front leg bar 11, the rear end of the seat set 8 being hinged to the lower end of the lower handlebar tube 31, in particular, the rear end of the seat set 8 being hinged to the connecting base 33 and via the connecting base to the lower end of the lower handlebar tube 31, the front end of the elastic member 7 being fixed to the front portion of the seat set 8, and the elastic member 7 acting between the front portion of the seat set 8 and the rear leg bar 21. When the stroller collapses, the front leg bar 11 and the rear leg bar 21 are automatically brought together, and the seat set 8 is also rotated forward to move towards the front leg bar 11.

The stroller frame further comprises a left connector 70A for a left end of a front arm rest and a right connector 70B for a right end of the front arm rest, wherein the left and right connector are provided at the upper end of the rear leg bar. This ensures that when the stroller frame is in the collapsed state, and if the front arm rest is present, it forms a convenient carrying handle for the user to carry the collapsed stroller frame.

The left and right connector may be fixed to the upper end of the rear leg bar and maintain the same orientation as the rear leg bar. In this way the front arm rest may protrudes upwardly and form the uppermost part of the collapsed stroller frame.

The connecting base 33 comprises a protruding section 72 which in the unfolded state protrudes forward and in the collapsed state protrudes to the rear. The seat set 8 is connected to this protruding section of the connecting base via a seat hinge 77.

The seat hinge 77 is located at a distance 88 from the lower handlebar hinge 78 via which the lower handlebar tube 88 is connected to the rear leg 12. The distance 88 provides a lever which allows the pivoting lower handlebar tube 31 to pull the seat set 7 in a rearward direction as indicated with the arrow 90. This pulls the front leg toward the rear leg.

During the collapsing movement, the protruding section 72 pulls the seat section to the rear, thereby pulling the front leg bar toward the rear leg bar. In this way, the force of gravity pulling on the combined lower handlebar tube 31 and upper handlebar tube 32 and rotating these downward, pulls the front leg 11 toward the rear leg bar 12 during the collapsing. Hence the force of gravity assists the elastic member.

The rear leg bar 12 does not have any local bends, contrary to some strollers of the prior art. This adds to the overall simplicity of the construction.

The stroller frame further comprises a backrest set 9, the backrest set 9 comprising a U-shaped backrest bar 91, a connecting base 33 being connected to the lower end of the lower handlebar tube 31 which in turn is hinged to the middle portion of the rear leg bar 21. The end of the backrest bar 91 is hinged to the connecting base 33.

The rear end of the elastic member 7 is directly or indirectly fixed to the connecting base 33. For instance, the rear end of the elastic member 7 may be connected to a transverse rod which interconnects the right and left connecting base 33. The rear end of the elastic member 7 may also be directly fixed to the rear leg bar 21. When the stroller collapses, the front leg bar 11 and the rear leg bar 21 are automatically brought together, driving the connecting base 33 and the backrest bar 91 to, following the lower handlebar tube 31, move towards the rear leg bar 21.

The locking assembly 5 comprises a locking pin 51 provided in the lower handlebar tube 31 and a locking hole 52 provided in the sliding member 4, and the locking pin 51 can penetrate the lower handlebar tube 31 and be elastically engaged in the locking hole 52. When the locking assembly 5 is in the locked state, the locking pin 51 in the lower handlebar tube 31 is engaged in the locking hole 52 of the sliding member 4, so that the sliding member 4 is not slidable relative to the lower handlebar tube 31. In this case, the stroller frame is not collapsible from an unfolded state to a folded state, and thus the stroller frame does not unexpectedly collapse and injure the baby when the stroller is used. When the locking assembly 5 is in the unlocked state, the locking pin 51 is disengaged from the locking hole 52, and the sliding member 4 is slidable along the axial direction of the lower handlebar tube 31. In this case, the stroller frame is collapsible from an unfolded state to a folded state. In addition, the locking assembly 5 of the present invention has a simple structure and operates reliably.

A rotating base 34 is provided between the lower handlebar tube 31 and the upper handlebar tube 32, and a linkage member, in particular a pull cord 57, is disposed between the rotating base 34 and the locking pin 51. A different kind of linkage member such as a rod is also possible.

To fold the stroller frame, it is only necessary to rotate the upper handlebar tube 32, in particular rotate the upper handlebar tube 32 forward, so that it rotates relative to the lower handle bar tube 31 and is folded. In this case, the rotating base 34 rotates at the same time, thereby driving the pulling cord 57 to move so that the locking pin 51 is disengaged from the locking hole 52. In this case, the locking assembly 5 is in an unlocked state, and the stroller frame is automatically collapsible from an unfolded state to a folded state. When it is necessary to unfold the stroller frame, first unfold the other parts of the stroller frame in turn, and then rotate the upper handlebar tube 32 in the opposite direction, and the rotating seat 34 rotates at the same time. It may also be possible to pull the upper handle bar tube and in this unfold the collapsed stroller frame. The locking pin 51 is reset by the elastic force and inserted into the locking hole 52 so that the locking assembly 5 is locked when the stroller frame is an unfolded state.

The upper handlebar tube 32 is provided with an unlocking member 10 for unlocking or locking the upper handlebar tube 32 so that it is rotatable or fixed relative to the lower handlebar tube 31. To fold the stroller frame, it is only necessary to operate the unlocking member 10 so that the upper handlebar tube 32 is unlocked and operate it to rotate relative to the lower handlebar tube 31 and fold, thereby realizing automatic collapsing. When the stroller frame is unfolded, the unlocking member 10 locks the upper handlebar tube 32 so that it is not rotatable relative to the lower handlebar tube 32.

With specific reference to figure 4, when seen in side view in the collapsed state a wheel base axis 80 extends through the front wheel axis 61 and the rear wheel axis 63. A line 81 extending through the front wheel axis 61 and the connecting member 33 extends at an angle α of more than 75 degrees to the wheel base axis (80) , in particular more than 80 degrees.

A line 82 extending through the rear wheel axis 63 and the connecting member 33 extends at an angle (β) of more than 75 degrees to the wheel base axis 80, in particular more than 80 degrees.

A line 83 extending through the front wheel axis and the first hinge 66 extends at an angle (γ) of more than 75 degrees to the wheel base axis 80, in particular more than 80 degrees.

In the collapsed state the automatically collapsible stroller frame can stand upright. This is an advantage over many strollers of the prior art including the stroller of CN205971433.

In the collapsed state the stroller frame can stand on its four wheels, wherein the front leg bar and the rear leg bar extend in an essentially upward direction, more in particular a substantially upright direction, from respectively the front leg wheel and the rear leg wheel when the front leg wheel and the rear leg wheel are in contact with the ground.

When seen in side view during and after the collapsing movement the centre of gravity 90 of the automatically collapsible stroller frame stays substantially between the front leg wheel and the rear leg wheel, allowing the automatically collapsible stroller frame to collapse to the folded state while staying upright and to remain in the upright position after reaching the collapsed state.

During the collapsing the front wheels and the rear wheels stay in contact with the ground and the automatically collapsible stroller frame stays upright.

In the collapsed state in side view a first distance 74 between the front wheel axis 61 and the connecting base 33 is the same or substantially the same as a second distance 75 between the rear wheel axis 63 and the connecting base 33.

In the collapsed state when seen in side view the front wheel 60 and rear wheel 62 may overlap. This keeps the stroller frame compact in the collapsed state. The overlap should not be too much, or the stability will be negatively affected, unless the rotating base 34 provides additional stability by contacting the ground or almost contacting the ground.

In the collapsed state, when seen in side view the U-shaped upper handlebar tube 32 is located on an opposite side of the lower handle bar tube 31 as the rear leg bar 12 and is accessible for a user without any obstacles in order to be pulled upward and outward by the user, thereby unfolding the stroller frame.

Another embodiment of the present invention as shown in Figure 8 differs from the above-mentioned configuration only in that the upper end of the front leg bar 11, the lower end of the transmission member 6, and the upper end of the rear leg bar 21 are not coaxially hinged. Instead, the upper end of the front leg bar 11 is hinged to the upper end of the rear leg bar 21 and is not hinged to the lower end of the transmission member 6. Although the connection relationship of the front leg bar 11, the transmission member 6, and the rear leg bar 21 is slightly different from that of the first embodiment of the present invention, it is also possible to achieve all the technical effects of the first embodiment of the present invention.

A further embodiment of the present invention as shown in Figure 9 differs from the above-mentioned configuration only in that the upper end of the front leg bar 11, the lower end of the transmission member 6, and the upper end of the rear leg bar 21 are not coaxially hinged. Instead, the upper end of the front leg bar 11 is hinged to the lower end of the transmission member 6 and is not hinged to the upper end of the rear leg bar 21. Although the connection relationship of the front leg bar 11, the transmission member 6, and the rear leg bar 21 is slightly different from that of the first embodiment of the present invention, it is also possible to achieve all the technical effects of the first embodiment of the present invention.

When the present invention is used, the stroller frame is unfolded to a state shown in Figure 1 or Figure 2 (the unfolding operation still needs to be manually performed) . To collapse the stroller, it is only necessary to operate the unlocking member 10 so that the upper handlebar tube 32 is unlocked and operate it to rotate relative to the lower handlebar tube 31 and fold. In this case, the rotating base 34 rotates at the same time, thereby driving the pulling cord to move so that the locking pin 51 is disengaged from the locking hole 52. In this case, the locking assembly 5 is in an unlocked state. As shown in Figure 3, under the elastic pull of the elastic member 7, the front leg bar 11 and the rear leg bar 21 are automatically brought together, and the seat set 8 also rotates forward to move towards the front leg bar 11. At the same time, the transmission member 6 drives the sliding member 4 to slide down the axial direction of the lower handlebar tube 31, thereby driving the lower handlebar tube 31 to move towards the rear leg bar 21. The connecting base 33 and the backrest bar 91 are rotated to, following the lower handlebar tube 31, move towards the rear leg bar 21, thereby collapsing the whole stroller frame, which is very quick and convenient. As shown in Figure 4, the collapsed stroller frame, supported by the front and rear castors, stands upright. Therefore, it is possible to place the collapsed stroller upright without the need of laying it flat, thereby saving floor space.

While the present invention has been particularly described above with reference to preferred embodiments, it should be understood that said embodiments are not intended to limit the present invention and that those of ordinary skill in the art can make various modifications, equivalent substitutions, and improvements without departing from the spirit and scope of the present invention as defined by the claims.

Claims

Automatically collapsible stroller frame, characterized in that it comprises:

a front leg set (1) , the front leg set (1) comprising a front leg bar (11) ;

a rear leg set (2) , the rear leg set (2) comprising a rear leg bar (21) ;

a handlebar set (3) , the handlebar set (3) comprising a lower handlebar tube (31) and a U-shaped upper handlebar tube (32) that is rotatably disposed at an upper end of the lower handlebar tube (31) , the lower handlebar tube (31) being provided with a sliding member (4) that is slidable along its axial direction,

a locking assembly (5) being provided between the lower handlebar tube (31) and the sliding member (4) for locking or unlocking the sliding member (4) , the lower end of the lower handlebar tube (31) being hinged to a middle portion of the rear leg bar (21) ,

a transmission member (6) being hinged between the sliding member (4) and the upper portion of the rear leg bar (21) , and the upper end of the front leg bar (11) being hinged to the lower end of the transmission member (6) and/or the upper end of the rear leg bar (21) ; and

an elastic member (7) , the elastic member (7) being associated with, in particular disposed between, the front leg bar (11) and the rear leg bar (21) such that when the stroller frame collapses, the front leg bar (11) and the rear leg bar (21) are automatically brought close together under the elastic pulling of the elastic member (7) , thereby completing automatic collapsing.
Automatically collapsible stroller frame according to claim 1, characterized in that it further comprises a seat set (8) , the front portion of the seat set (8) being hinged to a middle portion of the front leg bar (11) , the rear end of the seat set (8) being hinged to the lower end of the lower handlebar tube (31) , in particular via a connecting base (33) , and the front end of the elastic member (7) being fixed to the front portion of the seat set (8) , in particular fixed to a front portion or to a middle portion of the seat set.
Automatically collapsible stroller frame according to claim 1 or 2, characterized in that it comprises the connecting base (33) being connected to the lower end of the lower handlebar tube (31) which is hinged to the middle portion of the rear leg bar (12) .
Automatically collapsible stroller frame according to claim 3, characterized in that it further comprises a backrest set (9) , the backrest set (9) comprising a U-shaped backrest bar (91) , the end of the backrest bar (91) being hinged to the connecting base (33) .
Automatically collapsible stroller frame according to claim 3 or 4, characterized in that the rear end of the elastic member (7) is fixed to the connecting base (33) or directly fixed to the rear leg bar (12) .
Automatically collapsible stroller frame according to any of the preceding claims, characterized in that the locking assembly (5) comprises a locking pin (51) disposed in the lower handlebar tube (31) and a locking hole (52) disposed in the sliding member (4) , and the locking pin (51) can penetrate the lower handlebar tube (31) and be elastically engaged in the locking hole (52) .
Automatically collapsible stroller frame according to any of the preceding claims, characterized in that a rotating base (34) is disposed between the lower handlebar tube (31) and the upper handlebar tube (32) , and a linkage member, in particular a pull cord (57) , is disposed between the rotating base (34) and the locking pin (51) .
Automatically collapsible stroller frame according to any of the preceding claims, characterized in that the upper handlebar tube (32) is provided with an unlocking member (10) for unlocking or locking the upper handlebar tube (32) so that it is rotatable or fixable relative to the lower handlebar tube (31) .
Automatically collapsible stroller frame according to any of the preceding claims, characterized in that the upper end of the front leg bar (11) , the lower end of the transmission member (6) and the upper end of the rear leg bar (21) are coaxially hinged.
Automatically collapsible stroller frame according to any of the preceding claims, characterized in that the upper end of the front leg bar (11) is hinged to the upper end of the rear leg bar (21) and is not hinged to the lower end of the transmission member (6) .
Automatically collapsible stroller frame according to any of the preceding claims 1-9, characterized in that the upper end of the front leg bar (11) is hinged to the lower end of the transmission member (6) and is not hinged to the upper end of the rear leg bar (21) .
Automatically collapsible stroller frame according to any one of the preceding claims 1-9, characterized in that the elastic member (7) is a spring or rubber band.
Automatically collapsible stroller frame according to any of the preceding claims, wherein the U-shaped upper handlebar tube is configured to rotate in a forward direction relative to the lower handlebar tube, in particular over an angle of more than 150 degrees, in order to collapse the automatically collapsible stroller frame.
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state the automatically collapsible stroller frame can stand upright.
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state the stroller frame can stand on its four wheels, wherein the front leg bar and the rear leg bar extend in an essentially upward direction, more in particular a substantially upright direction, from respectively the front leg wheel and the rear leg wheel when the front leg wheel and the rear leg wheel are in contact with the ground.
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view during and after the collapsing movement the centre of gravity of the automatically collapsible stroller frame stays substantially between the front leg wheel and the rear leg wheel, allowing the automatically collapsible stroller frame to collapse to the folded state while staying upright and to remain in the upright position after reaching the collapsed state.
Automatically collapsible stroller frame according to any of the preceding claims, wherein during the collapsing the front wheels and the rear wheels stay in contact with the ground and the automatically collapsible stroller frame stays upright.
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state in side view a first distance (74) between the front wheel axis (61) and the connecting base (33) is the same or substantially the same as a second distance (75) between the rear wheel axis (63) and the connecting base (33) .
Automatically collapsible stroller frame according to any of the preceding claims, wherein the first distance (74) is more than 90 percent and less than 110 percent of the second distance (75) , wherein more in particular the first distance (74) is more than 95 percent and less than 105 percent of the second distance (75) .
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view a first distance measured from the hinge between the front leg bar and the rear leg bar to a rotation axis of the front wheels is at least 90 percent, more in particular at least 95 percent of a second distance measured from the hinge between the front leg bar and the rear leg bar to a rotation axis of the rear wheels.
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state, when seen in side view the rotating base (34) is located at the rear wheels and the U-shaped upper handlebar tube (32) projects in an upward direction from the rotating base.
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state, when seen in side view the U-shaped upper handlebar tube (32) is located on an opposite side of the lower handle bar tube as the rear leg bar and is accessible for a user without any obstacles in order to be pulled upward and outward by the user, thereby unfolding the stroller frame.
Automatically collapsible stroller frame according to any of the preceding claims, wherein the sliding member (4) provided on the lower handlebar tube (31) is the only sliding member of the automatically collapsible stroller frame.
Automatically collapsible stroller frame according to any of the preceding claims, wherein there is no sliding member between the lower handlebar tube (31) and the rear leg bar (21) .
Automatically collapsible stroller frame according to any of the preceding claims, further comprising a left connector (70A) for a left end of a front arm rest and a right connector (70B) for a right end of the front arm rest, wherein the left and right connectors are provided at the upper end of the rear leg bar.
Automatically collapsible stroller frame according to claim 25, wherein the left and right connectors are fixed to the upper end of the rear leg bar.
Automatically collapsible stroller frame according to any of the preceding claims, wherein the left connector and the right connector are located at respectively the left and right first hinges (66) .
Automatically collapsible stroller frame according to any of the preceding claims, wherein the connecting base (33) comprises a protruding section (72) which in the unfolded state protrudes forward and in the folded state protrudes to the rear, and wherein the seat set (8) is connected to this protruding section of the connecting base.
Automatically collapsible stroller frame according to any of the preceding claims, wherein a seat hinge (77) where the seat is hinged to the connecting base (33) is located at a distance (88) from a lower handlebar hinge (78) where the lower handlebar tube (31) is connected to the rear leg (12) .
Automatically collapsible stroller frame according to any of the preceding claims, wherein during the collapsing movement, the protruding section (72) pulls the seat section to the rear, thereby pulling the front leg bar toward the rear leg bar.
Automatically collapsible stroller frame according to any of the preceding claims, wherein the rear leg bar does not have any local bends.
Automatically collapsible stroller frame according to any of the preceding claims, wherein a length of front leg bar (11) including a caster (85) is substantially the same as length of the rear leg bar (21) , more in particular more than 95 percent of a length of the rear leg bar (21) .
Automatically collapsible stroller frame according to any of the preceding claims, wherein in the collapsed state when seen in side view the front wheel and rear wheel overlap.
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view in the collapsed state a wheel base axis (80) extends through the front wheel axis (61) and the rear wheel axis (63) and wherein a line (81) extending through the front wheel axis (61) and the connecting member (33) extends at an angle (α) of more than 75 degrees to the wheel base axis (80) , in particular more than 80 degrees.
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view in the collapsed state the wheel base axis (80) extends through the front wheel axis (61) and the rear wheel axis (63) and wherein a line (82) extending through the rear wheel axis (63) and the connecting member (33) extends at an angle (β) of more than 75 degrees to the wheel base axis (80) , in particular more than 80 degrees.
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view in the collapsed state a wheel base axis (80) extends through the front wheel axis (61) and the rear wheel axis (63) and wherein a line (83) extending through the front wheel axis and the first hinge (66) extends at an angle (γ) of more than 75 degrees to the wheel base axis (80) , in particular more than 80 degrees.
Automatically collapsible stroller frame according to any of the preceding claims, wherein the lower handlebar tube (31) has a length which positions the rotating base (34) close to the ground, in particular at a distance to the ground of less than 5cm, preferably less than 3 cm in the collapsed state, more preferably is in contact with the ground when the collapsed stroller frame is in the upright position.
Automatically collapsible stroller frame according to any of the preceding claims, wherein when seen in side view during and after the collapsing movement the centre of gravity remains between the front leg wheel and the rotating base, in particular between the rear leg wheel and the rotating base.