Foldable wheelchair

Abstract

The foldable wheelchair comprises a chassis, a seat rod, a backrest rod and a bottom supporting rod, an adapter plate is arranged between the backrest rod and the seat rod, the middle of the adapter plate is fixedly connected with the rear end of the seat rod, the upper end of the adapter plate is rotationally connected with the middle of the backrest rod, and the seat rod, the backrest rod, the bottom supporting rod and the chassis can form a four-bar mechanism through the adapter plate; according to the foldable wheelchair, the pluggable lock pin is arranged at the lower end of the adapter plate, the lock hole matched with the lock pin is formed in the middle of the backrest rod, the lock pin can be inserted into or separated from the lock hole, locking or unlocking of the four-connecting-rod mechanism can be achieved, and therefore the foldable wheelchair can be unfolded or folded, and the foldable wheelchair is simple and light in overall structure and convenient to operate; in addition, due to the existence of the adapter plate, the height of the rotating joint of the rear end of the seat rod and the backrest rod can be increased, the seat rod can be parallel to the base plate as much as possible during folding, the closing degree of the folded seat rod and the base plate is increased, and the technical effects of reducing the total height and being convenient to carry are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of wheelchairs, and in particular relates to a foldable wheelchair which is simple, light and easy to carry. Background Art

[0002] A wheelchair is a medical device that assists patients in treatment and rehabilitation. For ease of storage, foldable wheelchairs have appeared on the market. Existing foldable wheelchairs are divided into two categories: those without a chassis and those with a chassis. A foldable wheelchair without a chassis supports the seat by rotating the connected front and rear wheel brackets, and folds in the front-to-back direction by bringing the front and rear wheel brackets closer together; a foldable wheelchair with a chassis folds in the up-and-down direction by raising and lowering the seat, but the seat lifting structure of this type of foldable wheelchair is mostly complex and bulky, making it inconvenient to carry. At the same time, to ensure riding comfort, the seat pole is higher in the front and lower in the back when unfolded, and is not parallel to the chassis. After folding, the seat pole is less close to the chassis, and the overall height is relatively high. Summary of the invention

[0003] The purpose of the present invention is to overcome one or more disadvantages of the prior art and to provide a simple, lightweight and easy-to-carry foldable wheelchair.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is that the foldable wheelchair comprises:

[0005] Chassis;

[0006] A seat rod, the seat rod being higher in the front and lower in the back and being arranged above the chassis;

[0007] A backrest rod, the backrest rod extends obliquely from the upper rear to the lower front, the backrest rod is located outside the seat rod, and the lower end of the backrest rod is rotatably connected to the chassis;

[0008] A bottom support rod, the bottom support rod is located in front of the backrest rod and below the seat rod, the upper end of the bottom support rod is rotatably connected to the front part of the seat rod, and the lower end of the bottom support rod is rotatably connected to the chassis;

[0009] The foldable wheelchair also includes an adapter plate located between the backrest rod and the seat rod, the middle portion of the adapter plate is fixedly connected to the rear end portion of the seat rod, the upper end portion of the adapter plate is rotatably connected to the middle portion of the backrest rod, so that the seat rod is connected to the backrest rod, the bottom support rod and the chassis through the adapter plate to form a four-bar linkage, the lower end portion of the adapter plate is provided with a pluggable locking pin, the middle portion of the backrest rod is provided with a locking hole matching the locking pin, when the locking pin is inserted into the locking hole, the four-bar linkage is locked, and the foldable wheelchair remains in the unfolded state, when the locking pin is disengaged from the locking hole, the four-bar linkage is unlocked, and the backrest rod can be flipped forward and downward to make the seat rod move closer to the chassis, so that the foldable wheelchair is transformed into a folded state.

[0010] Preferably, when the foldable wheelchair is in an unfolded state, the adapter plate coincides with the projection of the backrest rod in the left-right direction, and when the foldable wheelchair is in a folded state, the seat rod is parallel to the chassis.

[0011] Preferably, the surface of the adapter plate facing the seat post is vertically connected with a first supporting rib, the first supporting rib extends in the left-right direction and supports the lower surface of the rear end of the seat post, and the rear end surface of the adapter plate is vertically connected with a second supporting rib, the second supporting rib extends in the left-right direction and seals the rear end surface of the seat post.

[0012] Further preferably, the projections of the first supporting rib and the second supporting rib in the front-rear direction are both triangular.

[0013] Preferably, the length difference of the opposite sides of the four-bar linkage does not exceed 5%.

[0014] Preferably, a nut is connected to the surface of the lower end of the adapter plate facing the seat rod, a hollow rod is connected to the inner thread of the nut, the hollow rod passes through the adapter plate, and the locking pin is insertably disposed in the hollow rod.

[0015] Further preferably, the locking pin is thick on the outside and thin on the inside, and a step is formed on its surface. The inner end of the hollow rod is provided with an annular flange protruding inward, and an annular cavity is formed between the annular flange and the step. A spring is provided in the annular cavity, and the two ends of the spring are respectively pressed against the annular flange and the step.

[0016] Preferably, the inner end of the locking pin is provided with a radial through hole, and the foldable wheelchair further comprises an unlocking strap, and the two ends of the unlocking strap are locked in the radial through holes of the two locking pins located on both sides.

[0017] Preferably, the foldable wheelchair further comprises an armrest rod, the lower end of the armrest rod is rotatably connected to the middle portion of the backrest rod, and the armrest rod, the adapter plate and the backrest rod share a same rotation axis.

[0018] Preferably, a front wheel assembly is provided at the bottom front portion of the chassis, a rear wheel assembly is provided at the bottom rear portion of the chassis, a foot pedal is connected to the front end portion of the chassis, and a battery pack is supported at the rear end portion of the chassis.

[0019] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0020] The foldable wheelchair provided by the present invention comprises a chassis, a seat rod, a backrest rod and a bottom support rod. An adapter plate is arranged between the backrest rod and the seat rod so that the middle part of the adapter plate is fixedly connected to the rear end part of the seat rod and the upper end part of the adapter plate is rotatably connected to the middle part of the backrest rod, so that the seat rod can form a four-bar linkage with the backrest rod, the bottom support rod and the chassis through the adapter plate. A pluggable locking pin is arranged at the lower end part of the adapter plate and a locking hole matching the locking pin is arranged at the middle part of the backrest rod. The locking pin can be inserted into or out of the locking hole to realize locking or unlocking of the four-bar linkage, thereby realizing the unfolding or folding of the foldable wheelchair. The overall structure is simple and light, and the operation is convenient. Due to the existence of the adapter plate, the height of the rotation connection between the rear end part of the seat rod and the backrest rod can be raised, so as to better match the backrest rod, the bottom support rod and the chassis, so that the four-bar linkage is parallelogram or approximately flat quadrilateral. When folding, the seat rod can be parallel to the chassis as much as possible, and the degree of closeness between the seat rod and the chassis after folding is improved, so as to realize the technical effect of reducing the total height and being easy to carry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of a preferred embodiment of the present invention, in which the unlocking handle is hidden.

[0022] Figure 2 yes Figure 1 Schematic diagram of the left side, at this time, the foldable wheelchair is in the unfolded state.

[0023] Figure 3 yes Figure 2 Schematic cross-sectional view along the AA direction.

[0024] Figure 4 yes Figure 3 A local enlarged schematic diagram of point B in the middle.

[0025] Figure 5 yes Figure 3 Schematic cross-sectional view in the CC direction.

[0026] Figure 6 yes Figure 2 Schematic diagram of a foldable wheelchair in the folding process.

[0027] Figure 7 yes Figure 2 Schematic diagram of a foldable wheelchair in a folded state.

[0028] Among them: 10. chassis; 11. front wheel assembly; 12. rear wheel assembly; 13. foot pedal; 14. battery pack; 20. seat rod; 30. backrest rod; 40. bottom support rod; 50. adapter plate; 51. first support rib; 52. second support rib; 53. nut; 54. hollow rod; 55. annular flange; 61. first rotating shaft; 62. second rotating shaft; 63. third rotating shaft; 64. fourth rotating shaft; 71. locking pin; 72. locking hole; 73. step; 74. annular cavity; 75. spring; 76. radial through hole; 77. unlocking strap; 80. handrail rod; 81. parallel rod; 82. tilt rod. DETAILED DESCRIPTION

[0029] The front-back, left-right, and up-down directions described in the present invention are the front-back, left-right, and up-down directions observed by the user when riding the foldable wheelchair.

[0030] like Figures 1 to 7As shown, the foldable wheelchair provided by the present invention comprises: a chassis 10, a seat rod 20, a backrest rod 30, a bottom support rod 40, and an adapter plate 50, wherein a front wheel assembly 11 is provided at the bottom front portion of the chassis 10, a rear wheel assembly 12 is provided at the bottom rear portion of the chassis 10, and the rear wheel assembly 12 comprises a hub motor, a foot pedal 13 is further connected to the front end portion of the chassis 10, and a battery pack 14 is supported at the rear end portion of the chassis 10, and the battery pack 14 is used to supply power to the hub motor; the seat rod 20 is arranged on the chassis 10 with a high front and a low back. 0; the backrest rod 30 extends obliquely from the upper rear to the lower front. When the foldable wheelchair is in the unfolded state, the angle between the backrest rod 30 and the vertical direction is preferably 12° to 16°. In the present embodiment, the angle is 14°. The backrest rod 30 is located outside the seat rod 20. The lower end of the backrest rod 30 is rotatably connected to the chassis 10 through the first rotating shaft 61. The bottom support rod 40 is located in front of the backrest rod 30 and below the seat rod 20. The upper end of the bottom support rod 30 is connected to the front of the seat rod 20. The adapter plate 50 is rotatably connected to the backrest rod 30 and the seat rod 20 through the second rotation axis 62, and the lower end of the bottom support rod 30 is rotatably connected to the chassis 10 through the third rotation axis 63; the adapter plate 50 is located between the backrest rod 30 and the seat rod 20, the middle part of the adapter plate 50 is fixedly connected to the rear end of the seat rod 20, and the upper end of the adapter plate 50 is rotatably connected to the middle part of the backrest rod 30 through the fourth rotation axis 64, and the fourth rotation axis 64 is higher than the seat rod 20, so that the seat rod 20 is connected to the backrest rod 30, the bottom support rod 40, and the chassis 10 through the adapter plate 50. A four-bar linkage is formed, a pluggable locking pin 71 is provided at the lower end of the adapter plate 50, and a locking hole 72 matching the locking pin 71 is provided in the middle of the backrest rod 30. When the locking pin 71 is inserted into the locking hole 72, the four-bar linkage is locked, and the foldable wheelchair remains in the unfolded state; when the locking pin 71 is disengaged from the locking hole 72, the four-bar linkage is unlocked, and the seat rod 20 can be moved closer to the chassis 10 by flipping the upper end of the backrest rod 30 forward and downward, thereby transforming the foldable wheelchair into a folded state.

[0031] The advantage of such an arrangement is that it can not only facilitate the unfolding or folding of the foldable wheelchair, but also make the overall structure of the foldable wheelchair simple, light and easy to operate; due to the existence of the adapter plate, the height of the rotation connection between the rear end of the seat rod and the backrest rod can be raised, so as to better match the backrest rod, the bottom support rod and the chassis, so that the four-bar linkage is a parallelogram or a nearly flat quadrilateral, and when folded, the seat rod can be as parallel to the chassis as possible, and the degree of closeness between the seat rod and the chassis after folding is improved, so as to achieve the technical effect of reducing the overall height and facilitating carrying.

[0032] In this embodiment, when the foldable wheelchair is in the unfolded state, the projection of the adapter plate 50 and the backrest rod 30 in the left-right direction coincide with each other, and when the foldable wheelchair is in the folded state, the seat rod 20 is parallel to the chassis 10 .

[0033] To improve strength, in this embodiment, a first supporting rib 51 is vertically connected to the surface of the adapter plate 50 facing the seat rod 20. The first supporting rib 51 extends in the left-right direction and supports the lower surface of the rear end of the seat rod 20. A second supporting rib 52 is vertically connected to the rear end surface of the adapter plate 50. The second supporting rib 52 extends in the left-right direction and seals the rear end surface of the seat rod 20. Furthermore, the projections of the first supporting rib 51 and the second supporting rib 52 in the front-to-back direction are both triangular.

[0034] To ensure that the above-mentioned four-bar linkage is a parallelogram or an approximately flat quadrilateral, the length difference of the opposite sides of the four-bar linkage does not exceed 5%. Specifically, in this embodiment, the distance between the first rotating axis 61 and the third rotating axis 63 is 254.88 mm, the distance between the second rotating axis and the fourth rotating axis is 251.90 mm, the distance between the second rotating axis 62 and the third rotating axis 63 is 201.52 mm, and the distance between the fourth rotating axis 64 and the first rotating axis 61 is 192.34 mm.

[0035] To facilitate guiding, in the present embodiment, a nut 53 is welded to the surface of the seat rod 20 at the lower end of the adapter plate 50, and a hollow rod 54 is connected to the inner thread of the nut 53. The hollow rod 54 passes through the adapter plate 50, and a locking pin 71 is inserted and removably inserted into the hollow rod 54. To achieve automatic locking in the unfolded state, the locking pin 71 is thick on the outside and thin on the inside, and a step 73 is formed on its surface. The inner end of the hollow rod 54 is provided with an annular flange 55 protruding inwardly, and an annular cavity 74 is formed between the annular flange 55 and the step 73. A spring 75 is provided in the annular cavity 74, and the two ends of the spring 75 are respectively pressed against the annular flange 55 and the step 73. The spring 75 has a tendency to drive the locking pin 71 to move outward. When the foldable wheelchair is transformed to the unfolded state, the spring 75 can drive the locking pin 71 to insert into the locking hole 72 to achieve automatic locking.

[0036] To facilitate synchronous unlocking on both sides, in the present embodiment, the inner end of the locking pin 71 is provided with a radial through hole 76. The foldable wheelchair also includes an unlocking strap 77. The two ends of the unlocking strap 77 are locked in the radial through holes 76 of the two locking pins 71 on both sides. When unlocking, one hand pushes the upper end of the backrest rod 30 and the other hand pulls the middle of the unlocking strap 77 backwards, so that the locking pins 71 on both sides can be synchronously disengaged from the locking holes 72, thereby achieving synchronous unlocking and transforming the foldable wheelchair to the folded state. The operation is convenient and smooth.

[0037] To improve the comfort of use, in the present embodiment, the foldable wheelchair further includes an armrest rod 80, which includes a parallel rod 81 parallel to the seat rod 20 and an inclined rod 82 connected to the bottom rear portion of the parallel rod 81 and extending obliquely rearward and downward (when the foldable wheelchair is in the unfolded state). The lower end portion of the inclined rod 82 is rotatably connected to the middle portion of the backrest rod 30, and the inclined rod 82, the adapter plate 50 and the backrest rod 30 share the same rotation axis, that is, the lower end portion of the inclined rod 82 is also rotatably connected to the middle portion of the backrest rod 30 via the fourth rotation axis 64.

[0038] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A foldable wheelchair, comprising: Chassis; A seat rod, the seat rod being higher in the front and lower in the back and being arranged above the chassis; A backrest rod, the backrest rod extends obliquely from the upper rear to the lower front, the backrest rod is located outside the seat rod, and the lower end of the backrest rod is rotatably connected to the chassis; A bottom support rod, the bottom support rod is located in front of the backrest rod and below the seat rod, the upper end of the bottom support rod is rotatably connected to the front part of the seat rod, and the lower end of the bottom support rod is rotatably connected to the chassis; Features: The foldable wheelchair also includes an adapter plate located between the backrest rod and the seat rod, the middle portion of the adapter plate is fixedly connected to the rear end portion of the seat rod, the upper end portion of the adapter plate is rotatably connected to the middle portion of the backrest rod, so that the seat rod is connected to the backrest rod, the bottom support rod and the chassis through the adapter plate to form a four-bar linkage, the lower end portion of the adapter plate is provided with a pluggable locking pin, the middle portion of the backrest rod is provided with a locking hole matching the locking pin, when the locking pin is inserted into the locking hole, the four-bar linkage is locked, and the foldable wheelchair remains in the unfolded state, when the locking pin is disengaged from the locking hole, the four-bar linkage is unlocked, and the backrest rod can be flipped forward and downward to make the seat rod move closer to the chassis, so that the foldable wheelchair is transformed into a folded state.

2. The foldable wheelchair according to claim 1, characterized in that: When the foldable wheelchair is in an unfolded state, the adapter plate coincides with the projection of the backrest rod in the left-right direction, and when the foldable wheelchair is in a folded state, the seat rod is parallel to the chassis.

3. The foldable wheelchair according to claim 1, characterized in that: The surface of the adapter plate facing the seat post is vertically connected to a first supporting rib, the first supporting rib extends in the left-right direction and supports the lower surface of the rear end of the seat post, and the rear end surface of the adapter plate is vertically connected to a second supporting rib, the second supporting rib extends in the left-right direction and seals the rear end surface of the seat post.

4. The foldable wheelchair according to claim 3, characterized in that: The projections of the first supporting rib and the second supporting rib in the front-rear direction are both triangular.

5. The foldable wheelchair according to claim 1, characterized in that: The length difference of the opposite sides of the four-bar linkage does not exceed 5%.

6. The foldable wheelchair according to claim 1, characterized in that: A nut is connected to the surface of the lower end of the adapter plate facing the seat rod, a hollow rod is connected to the inner thread of the nut, the hollow rod passes through the adapter plate, and the locking pin is inserted and removable in the hollow rod.

7. The foldable wheelchair according to claim 6, characterized in that: The locking pin is thick on the outside and thin on the inside, and a step is formed on its surface. The inner end of the hollow rod is provided with an annular flange protruding inward, and an annular cavity is formed between the annular flange and the step. A spring is provided in the annular cavity, and the two ends of the spring are respectively pressed against the annular flange and the step.

8. The foldable wheelchair according to claim 1, characterized in that: The inner end of the locking pin is provided with a radial through hole. The foldable wheelchair further comprises an unlocking handle. The two ends of the unlocking handle are locked in the radial through holes of the two locking pins located on both sides.

9. The foldable wheelchair according to claim 1, characterized in that: The foldable wheelchair also includes an armrest rod, the lower end of the armrest rod is rotatably connected to the middle part of the backrest rod, and the armrest rod, the adapter plate and the backrest rod share the same rotation axis.

10. The foldable wheelchair according to claim 1, characterized in that: The front bottom portion of the chassis is provided with a front wheel assembly, the rear bottom portion of the chassis is provided with a rear wheel assembly, the front end portion of the chassis is connected with a pedal, and the rear end portion of the chassis supports a battery pack.

Images