shock absorber

Abstract

A shock absorber is adapted to be installed on a wheelchair having a seat portion and a back portion. The shock absorber comprises a base tube connected to the seat portion and having a transverse slot, a resilient member in the base tube, a top rod engaging the back portion and pressing against the resilient member, and an outer tube sleeved on the base tube and the top rod. The top rod has a rod body and an axially slidable slot and a transversely limiting slot connected thereto. The outer tube has an inwardly protruding limiting protrusion rotatable between a locking position and an extension position. In the locking position, the limiting protrusion penetrates into the transverse slot and the limiting slot to limit the top rod. In the extension position, the limiting protrusion penetrates into the transverse slot and the slidable slot to allow the top rod to be pressed against the resilient member. With the design of the outer tube, the top rod and the resilient member, a user sitting on the wheelchair can stretch his body safely and timely, and the back portion can be buffered against a pressing force and automatically reset.

Description

Technical Field

[0001] This invention relates to a shock absorption device, and more particularly to a shock absorber for a wheelchair. Background Technology

[0002] Existing wheelchairs for users with mobility impairments are similar to regular seats, with the backrest fixed vertically to the back edge of the seat. Because the angle between the backrest and the seat is fixed and cannot be changed, users who maintain the same sitting posture for a long time will experience muscle stiffness and soreness if they cannot stretch their limbs.

[0003] Therefore, there is currently a type of wheelchair with a backrest that can recline relative to the seat, especially designed for users with limb movement disorders such as cerebral palsy who are unable to stand or sit independently. This allows users to stretch their bodies appropriately in the wheelchair after sitting for a long time, so as to exercise and stretch the muscles in their shoulders and back.

[0004] However, the primary purpose of wheelchairs is to assist users who are unable to walk in moving freely. Therefore, one of the research and development goals in this field is to provide users with a comfortable and safe environment to stretch their bodies in a wheelchair. Summary of the Invention

[0005] The purpose of this invention is to provide a shock absorber that can at least overcome the shortcomings of the prior art.

[0006] The shock absorber of the present invention is suitable for use in a wheelchair, the wheelchair having a base portion and a backrest extending upward from the rear side edge of the base portion, the shock absorber comprising a base tube, an elastic element, a top support rod, and an outer tube.

[0007] The base tube is adapted to connect with the base of the wheelchair and includes a circular tube wall and a transverse groove disposed on the circular tube wall, the circular tube wall enclosing a chamber with an open end.

[0008] The elastic element is disposed in the chamber.

[0009] The top end of the top support rod connects to the chair back, and the bottom end extends through the open end into the chamber of the base tube and presses against the elastic member. The top support rod has a rod body, a sliding groove formed on the rod body and extending along the extension direction of the rod body axis, and a limiting groove that connects to the bottom side of the sliding groove and extends laterally.

[0010] The outer sleeve has an inner circumferential surface and a limiting protrusion extending inward from the inner circumferential surface. The outer sleeve is fitted over the base tube and the top support rod and can rotate axially between a locked position and a telescopic position. In the locked position, the limiting protrusion simultaneously enters the transverse groove and the limiting slot, causing the top support rod to be limited and maintain a fixed relative position with the base tube. In the telescopic position, the limiting protrusion simultaneously enters the transverse groove and the sliding groove, causing the top support rod to be subjected to force and press down on the elastic member relative to the base tube along the axis.

[0011] The shock absorber of the present invention further includes an outer peripheral surface spaced apart from the inner peripheral surface of the outer sleeve, and the shock absorber also includes a rotating handle fixedly disposed on the outer peripheral surface of the outer sleeve.

[0012] The shock absorber of the present invention includes a backrest of the wheelchair that can be tilted backward and connected to the base. The top side of the top support rod has a mounting hole extending along the axis. The shock absorber also includes a connecting support rod suitable for pivotally connecting to the bottom side of the backrest and fixedly installed between the top side of the top support rod. When the outer sleeve is in the telescopic position, the connecting support rod can be pressed down by the tilted backrest, causing the top support rod to move downward. The elastic element has a constant elastic force that pushes the top support rod upward, allowing the connecting support rod to drive the backrest to return to its original position.

[0013] The shock absorber of the present invention further includes a base tube having a seat member located on the top side of the base portion of the wheelchair, and the circular tube wall is screwed onto the seat member.

[0014] The shock absorber of the present invention has a base member having a surrounding wall portion around the axis, and the base tube further having a support member abutting against the top side of the surrounding wall portion of the base member and having a supporting surface, and the elastic member being placed on the supporting surface.

[0015] In the shock absorber of the present invention, the transverse groove of the base tube is located in the extension direction of the axis corresponding to the limiting groove of the top support rod.

[0016] The beneficial effects of this invention are as follows: Utilizing the design of the outer sleeve, top support rod, and elastic element, when the wheelchair is in a stable environment such as a stationary position, the shock absorber can rotate from a locked position to a telescopic position, allowing the user in the wheelchair to safely extend their body. Furthermore, the elastic force of the elastic element can cushion the downward pressure on the backrest and automatically reset, providing great convenience and comfort. Attached Figure Description

[0017] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the accompanying drawings, wherein:

[0018] Figure 1This is a perspective view illustrating an embodiment of the shock absorber of the present invention applicable to a wheelchair;

[0019] Figure 2 This is an exploded perspective view illustrating the described embodiment, omitting the connecting support rods;

[0020] Figure 3 This is a cross-sectional view illustrating the embodiment in the locked position;

[0021] Figure 4 This is a cross-sectional view from another angle, illustrating that when the outer sleeve of the embodiment is in the locking position, the limiting protrusion is located in the limiting groove of the top support rod;

[0022] Figure 5 It is similar Figure 4 A cross-sectional view at an angle illustrates that when the outer sleeve is in the telescopic position, the limiting protrusion is located in the sliding groove of the top support rod, and the top support rod is not pressed down;

[0023] Figure 6 It is similar Figure 4 A cross-sectional view at an angle illustrates that when the outer sleeve is in the telescopic position, the top support rod can be pressed down relative to the base tube, so that the limiting protrusion is located on the top side of the sliding groove. Detailed Implementation

[0024] See Figures 1 to 4 One embodiment of the shock absorber of the present invention is applicable to a wheelchair 90. The wheelchair 90 includes a base portion 91 and a backrest 92 extending upward from the rear edge of the base portion 91. The base portion 91 includes a seat 911 and a plurality of casters 912 mounted on the bottom side of the seat 911. The backrest 92 is retractably connected to the seat 911. In this embodiment, the wheelchair 90 is a general wheelchair; in other variations, it could also be an electric wheelchair. Since there are many ways to connect the base portion 91 and the backrest 92 of the wheelchair 90, and these are not the focus of this invention, as long as the backrest 92 can recline relative to the base portion 91, specific details will not be elaborated here.

[0025] Furthermore, to clearly illustrate how the shock absorber is connected to the wheelchair 90, in Figure 1 Only the main structure of wheelchair 90 is shown, omitting commonly used soft components such as the seat cushion and backrest. These will be explained here first.

[0026] The shock absorber includes a base tube 1, an elastic element 2, a top support rod 3, a connecting support rod 4, an outer sleeve 5, and a rotating handle 6.

[0027] The base tube 1 includes a seat member 11 located on the top side of the base portion 91, a circular tube wall 12 fixedly disposed on the rear side of the seat 911 and sleeved on the seat member 11, a transverse groove 13 formed in the circular tube wall 12, and a resting member 14 located in the circular tube wall 12.

[0028] The base member 11 has a surrounding wall portion 111 surrounding an axis L, and an external threaded surface 112 formed on the top side of the outer periphery of the surrounding wall portion 111. The circular tube wall 12 extends vertically around the axis L and is screwed to the external threaded surface 112 of the surrounding wall portion 111. The two sides of the circular tube wall 12 are connected to the base portion 91 via two connecting plates 913. The circular tube wall 12 defines a chamber 121 that extends vertically along the axis L and has an upward-facing open end 122. The transverse groove 13 is formed radially through the top side of the circular tube wall 12 and extends arcuately along the circular tube wall 12. The abutment member 14 has an abutment ring 141 that rests against the top surface of the surrounding wall portion 111 of the base member 11, and an inner surrounding wall 142 that extends downward from the abutment ring 141 and passes through the inner surrounding wall 142 of the base member 11. The abutment ring 141 has a support surface 143 that is spaced vertically from the top surface of the enclosure portion 111.

[0029] The elastic element 2 is located in the chamber 121 and rests on the support surface 143 of the abutment 14. In this embodiment, the elastic element 2 is a compression spring.

[0030] The top support rod 3 includes a hollow rod body 31, forming a sliding groove 32 that radially penetrates the rod body 31 and extends vertically along the axis L, and a limiting groove 33 that radially penetrates the rod body 31, connects to the bottom side of the sliding groove 32, and extends horizontally. The top end of the rod body 31 forms a mounting hole 311 that penetrates vertically along the axis L, and the rod body 31, with its bottom end passing through the open end 122 of the circular tube wall 12, extends into the tube chamber 121 and is placed on the elastic member 2, such that the bottom sides of the limiting groove 33 and the sliding groove 32 correspond to the position of the transverse groove 13 of the circular tube wall 12 in the direction of the axis L.

[0031] The connecting support rod 4 is preferably screw-shaped and located between the chair back 92 and the top support rod 3. The top end of the connecting support rod 4 is pivotally connected to the bottom rear side of the chair back 92, and can be moved downward along the axis L when the chair back 92 is reclined. The bottom end of the connecting support rod 4 is screwed into the mounting hole 311 of the rod body 31.

[0032] It should be noted that in other variations of this embodiment, the base tube 1 can also be fixed to the base portion 91 in other ways, as long as the connecting support rod 4 can move downward relative to the base tube 1 when the backrest 92 tilts backward.

[0033] The outer sleeve 5 has a circular cross-section and includes an inner circumferential surface 51 surrounding the axis L, an outer circumferential surface 52 radially spaced from the inner circumferential surface 51, and a limiting protrusion 53 protruding inward from the inner circumferential surface 51. The outer sleeve 5 is fitted onto the top end of the circular tube wall 12 and the rod body 31, with the top end of the rod body 31 protruding upward. The limiting protrusion 53 also radially penetrates the transverse groove 13 and the limiting groove 33, or the transverse groove 13 and the sliding groove 32. The rotating handle 6 is fixedly mounted on the outer circumferential surface 52 of the outer sleeve 5.

[0034] In this embodiment, the outer sleeve 5 also has a through hole 54 penetrating the inner peripheral surface 51 and the outer peripheral surface 52. The limiting protrusion 53 has a limiting portion 531 that protrudes radially inward from the inner peripheral surface 51 through the through hole 54, and an assembly portion 532 that protrudes radially outward from the limiting portion 531 through the through hole 54 and has external threads. During assembly, the limiting protrusion 53 is first inserted into the through hole 54, and then the rotating handle 6 is screwed and fixed to the assembly portion 532 of the limiting protrusion 53, thereby completing the installation of the outer sleeve 5 and the rotating handle 6.

[0035] See Figures 4 to 6 The outer sleeve 5 can be positioned relative to the base tube 1, with the axis L as the center, in a locked position (e.g., Figure 4 ) and a telescopic position (e.g. Figure 5 Rotate between. The outer sleeve 5 rotates as follows. Figure 4 When the locking position is shown, the limiting protrusion 53 simultaneously extends into the transverse groove 13 and the limiting groove 33, the top support rod 3 is limited and maintains a fixed relative position with the base tube 1, and cannot move relative to the base tube 1 along the axis L. The outer sleeve 5 is in such a position as shown. Figure 5 When in the telescopic position shown, the limiting protrusion 53 simultaneously inserts into the transverse groove 13 and the sliding groove 32, allowing the top support rod 3 to move as shown. Figure 6 As shown, the elastic element 2 is pressed down by the connecting support rod 4 relative to the base tube 1 along the axis L.

[0036] See Figure 1 , Figure 3 , Figure 4When the wheelchair 90 needs to be moved, for the user's safety, it is desirable that the backrest 92 of the wheelchair 90 not recline. Therefore, the outer sleeve 5 can be controlled to be in the locked position. At this time, the limiting protrusion 53 is located in the limiting groove 33, preventing the top support rod 3 from moving relative to the base tube 1 along the axis L, and also preventing the connecting support rod 4 from moving. Therefore, the backrest 92 is fixed and supported by the connecting support rod 4 and cannot tilt.

[0037] See Figure 1 , Figure 3 , Figure 5 When movement is not required, the wheelchair 90 allows the user to extend their body. The rotating handle 6 is positioned along arrow A (as shown). Figure 3 Rotate clockwise until the outer sleeve 5 is moved to the telescopic position. At this time, the limiting protrusion 53 is still located in the transverse groove 13 and is switched to pass through the sliding groove 32. Please refer to further details. Figure 6 When the user presses down on the backrest 92, causing it to recline, the connecting support rod 4 moves downward and presses down on the top support rod 3. When the user stops pressing down on the backrest 92, the elastic element 2 exerts a constant driving force to push the top support rod 3 upward, causing it to move upward. This causes the connecting support rod 4 to move upward as well, resulting in the backrest 92 rotating forward to its original position (e.g., ...). Figure 5 At this point, the outer sleeve 5 can be rotated back to the locking position (e.g., Figure 4 (As shown).

[0038] Because the outer sleeve 5 can rotate between the locked position and the telescopic position, the wheelchair 90 can use the shock absorber to control whether the backrest 92 can recline backward or recline to a predetermined angle (that is, when the top support rod 3 is pressed down to the limit protrusion 53 is located on the top side of the sliding groove 32) and automatically return to its original position. This allows the user sitting in the wheelchair 90 to stretch their body appropriately and safely. After stretching, the backrest 92 can also elastically and automatically return to its original position, preventing the user from being restricted to a fixed reclining angle of the backrest 92 and becoming rigid in the same sitting posture, which is very comfortable and convenient. In addition, by using the outer sleeve 5 in conjunction with the rotating handle 6 to rotate to the locked position, it can also prevent the user from arbitrarily stretching their body and rotating the backrest 92 when the center of gravity shifts while the wheelchair 90 is moving, thereby preventing the user from losing their balance and falling out of the wheelchair 90, which is very safe.

[0039] In summary, the shock absorber of the present invention utilizes the ability of the outer sleeve 5 to rotate between the locked position and the telescopic position. Combined with the design of the top support rod 3 and the elastic element 2, it effectively prevents the top support rod 3 from moving up and down in the locked position, thereby preventing the chair back 92 from tilting back and ensuring the safety of the user in the wheelchair 90 during movement. On the other hand, in the telescopic position, the top support rod 3 is pressed down when the chair back 92 tilts backward, and the elastic element 2 cushions the downward pressure. It is also automatically moved upward by the elastic element 2, allowing the chair back 92 to automatically return to its original position, effectively providing the user with comfortable body extension. Therefore, the purpose of the present invention is indeed achieved.

[0040] The above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the present invention.

Claims

1. A shock absorber suitable for installation on a wheelchair, the wheelchair having a base and a backrest extending upward from the rear side edge of the base, characterized in that, The shock absorber includes: A base tube, adapted to be connected to the base of the wheelchair, includes a circular tube wall and a transverse groove provided on the circular tube wall, the circular tube wall enclosing a chamber with an open end; An elastic element is disposed in the chamber; A top support rod, with its top end connected to the chair back and its bottom end extending through the open end into the chamber of the base tube and pressing against the elastic member, the top support rod having a rod body, a sliding groove formed on the rod body and extending along the axis of the rod body, and a limiting groove communicating with the bottom side of the sliding groove and extending laterally; the transverse groove of the base tube is positioned in the direction of the axis of extension corresponding to the limiting groove of the top support rod; and The outer sleeve has an inner circumferential surface and a limiting protrusion extending inward from the inner circumferential surface. The outer sleeve is fitted over the base tube and the top support rod. The outer sleeve also includes an outer circumferential surface spaced apart from the inner circumferential surface and a through hole penetrating the inner and outer circumferential surfaces. The limiting protrusion has a limiting portion extending radially inward from the inner circumferential surface through the through hole and an assembly portion extending radially outward from the limiting portion through the through hole and having external threads. It is rotatable between a locked position and a telescopic position. When the outer sleeve is in the locked position, the limiting protrusion simultaneously enters the transverse groove and the limiting groove, causing the top support rod to be limited and maintain a fixed relative position with the base tube. When the outer sleeve is in the telescopic position, the limiting protrusion simultaneously enters the transverse groove and the sliding groove, causing the top support rod to be subjected to force and press down on the elastic element relative to the base tube along the axis. The shock absorber also includes a rotating handle fixedly disposed on the outer peripheral surface of the outer sleeve, and the rotating handle is screwed to the assembly part of the limiting protrusion.

2. The shock absorber according to claim 1, characterized in that: The backrest of the wheelchair can recline backward and is connected to the base. The top side of the top support rod has a mounting hole extending along the axis. The shock absorber also includes a connecting support rod suitable for pivoting to the bottom side of the backrest and fixing to the top side of the top support rod. When the outer sleeve is in the telescopic position, the connecting support rod can be pressed down by the reclining backrest, causing the top support rod to move downward. The elastic element has a constant elastic force that pushes the top support rod upward, allowing the connecting support rod to drive the backrest to return to its original position.

3. The shock absorber according to claim 1, characterized in that: The base tube also has a seat body located on the top side of the base portion of the wheelchair, and the circular tube wall is screwed onto the seat body.

4. The shock absorber according to claim 3, characterized in that: The base member has a surrounding wall portion around the axis, and the base tube also has a support member that rests against the top side of the surrounding wall portion of the base member and has a supporting surface, and the elastic member is placed on the supporting surface.

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