Foldable wheelchairs

Abstract

A foldable wheelchair includes a rear wheel frame, a seat frame, a front wheel frame, an armrest frame, an oblique connecting rod and a locking mechanism. The locking mechanism comprises two movable plates, a connecting beam and a tension spring. The movable plates are each hinged to the seat frame connected to respective ends of the connecting beam. One end of the tension spring is fixed to the movable plate and the other end is fixed to the seat frame. The side of the movable plate closest to the tension spring faces away from the seat frame and the front wheel frame. The top of the front wheel frame abuts against the bottom of the seat frame when the foldable wheelchair is in use. By arranging the front wheel frame to be hinged to the seat frame, the seat frame to be hinged to the rear wheel frame, the armrest frame to be hinged to the rear wheel frame and the seat frame, and the oblique connecting rod to be hinged to the front wheel frame and the rear wheel frame, the wheelchair as a whole can be unfolded for use and folded for storage, and is convenient to use.

Description

[0001] Foldable wheelchairs

[0002] Technical Field

[0003] The invention relates to foldable wheelchairs.

[0004] Background Art

[0005] The design of traditional wheelchairs only considers the basic mobility function and structural stability. Most of them are fixed structures and cannot be folded for storage. Therefore, they take up a large indoor space when not in use and are not convenient for storage. In order to solve this problem, foldable wheelchairs have gradually appeared on the market. However, existing foldable wheelchairs often have complex folding structures and cumbersome operations. In addition, the volume after folding is still large, occupying more space, and the effect is not ideal. In addition, due to the lack of a reliable locking mechanism, these folding wheelchairs may lack sufficient stability and safety during the folding and unfolding process. Not only are the load-bearing capacity and service life poor, but they may also be suddenly unlocked during use, causing the wheelchair to fold, posing a safety hazard to the user.

[0006] Summary of the Invention

[0007] An object of the invention is to provide foldable wheelchair designs that solve one or more technical problems existing in the above-mentioned background technology, or at least to provide an alternative to existing products on the market.

[0008] The invention provides a foldable wheelchair comprises a rear wheel frame, a seat frame, a front wheel frame, an armrest frame, an oblique connecting rod and a locking mechanism, wherein the front wheel frame is hinged to the bottom of the seat frame, the rear side of the seat frame is hinged to the middle part of the rear wheel frame, the armrest frame is respectively hinged to the rear wheel frame and the seat frame, one end of the oblique connecting rod is hinged to the front wheel frame, the other end of the oblique connecting rod is hinged to the rear wheel frame, the vertical height of the hinge point of the oblique connecting rod and the front wheel frame is higher than the vertical height of the hinge point of the oblique connecting rod and the rear wheel frame; the locking mechanism comprises two movable plates, a connecting beam and a tension spring, the movable plates are hinged to the seat frame, the movable plates are respectively connected to the two ends of the connecting beam, one end of the tension spring is fixed to the movable plate, the other end of the tension spring is fixed to the seat frame, the side of the movable plate close to the tension spring is against the seat frame and the front wheel frame, and the top of the front wheel frame is against the bottom of the seat frame.

[0009] Preferably, the locking mechanism further includes a first locking pin and a second locking pin, the first locking pin is arranged on the inner side of the seat frame, the second locking pin is arranged on the inner side of the front wheel frame, and the movable plate abuts against the first locking pin and the second locking pin.

[0010] Preferably, a raised limiting portion and a hook-shaped limiting portion are provided on the upper and lower sides of a side of the movable plate close to the tension spring, and the raised limiting portion and the hook-shaped limiting portion are respectively abutted against the first locking pin and the second locking pin.

[0011] Preferably, it also includes a first connecting member, the top of which is provided with a first positioning groove matching the bottom of the seat frame, the top of the first connecting member is connected to the seat frame, the bottom of the first connecting member is provided with a hinge shaft, the top of the front wheel frame is provided with a second positioning groove matching the bottom of the seat frame, the first positioning groove and the second positioning groove are both in contact with the bottom of the front wheel frame, a connecting portion is provided on one side of the front wheel frame, and the connecting portion is hinged to the first connecting member through the hinge shaft.

[0012] Preferably, the locking mechanism also includes a first fixing bolt and a second fixing bolt, one end of the tension spring is fixed to the movable plate through the first fixing bolt, the other end of the tension spring is fixed to the first connecting member through the second fixing bolt, and the second fixing bolt is coaxially arranged with the hinge axis.

[0013] Preferably, it also includes two second connecting members and a reinforcing beam, the two second connecting members are arranged on the left and right sides of the middle part of the rear wheel frame, the two ends of the reinforcing beam are respectively connected to the two second connecting members, one end of the second connecting member is connected to the rear wheel frame, and the other end of the second connecting member extends forward and is hinged to the seat frame.

[0014] Preferably, the armrest frame includes an armrest rod, a third connecting member and a support rod, one end of the armrest rod is hinged to the rear wheel frame, one end of the support rod is hinged to the seat frame, the third connecting member is hinged to the other end of the support rod and the bottom of the armrest rod, and a third positioning groove matching the bottom of the armrest frame is provided on the top of the third connecting member, and the third positioning groove is in contact with the bottom of the armrest frame.

[0015] Preferably, it further comprises a footrest bracket, the front wheel frame is provided with a footrest support rod extending downward, and the footrest bracket is hinged to the footrest support rod. Preferably, it also includes a front wheel assembly, a rear wheel assembly, a seat cushion, a back cushion and an armrest pad, the front wheel assembly is arranged at the bottom of the front wheel frame, the rear wheel assembly is arranged at the bottom of the rear wheel frame, the back cushion covers the upper and middle part of the rear wheel frame, the cover is on the seat frame, and the armrest pad covers on the armrest frame.

[0016] Preferably, the front wheel assembly is rotatably connected to the bottom of the front wheel frame.

[0017] Compared with the prior art, the beneficial effect of embodiments of the foldable wheelchair are that by providing a front wheel frame hinged to a seat frame, the seat frame hinged to a rear wheel frame, an armrest frame hinged to the rear wheel frame and the seat frame, and an oblique connecting rod hinged to the front wheel frame and the rear wheel frame, the wheelchair as a whole can be unfolded for use and folded for storage, and is convenient to use. When unfolded for use, a movable plate of a locking mechanism remains in contact with the seat frame and the front wheel frame under the elastic biasing force of a tension spring, thereby locking the seat frame and the front wheel frame and so avoiding sudden unlocking during use that might cause the wheelchair to fold and cause a safety hazard.

[0018] Another aspect of the invention provides a foldable wheelchair comprising a rear wheel frame, a seat frame, a front wheel frame and at least one connecting rod connected to said rear wheel frame and said front wheel frame, wherein said seat frame comprises a forward end, an underside and two oppositely disposed arms extending rearwardly with respect to said forward end and having rearward ends hinge connected to said rear wheel frame by respective first hinge connections so that said seat frame is pivotable relative to said rear wheel frame from deployed position to a storage position in which said forward end is disposed closer to said rear wheel frame than when said seat frame is in said use position by a pivoting movement that is upwards and towards said rear wheel frame, and wherein said front wheel frame is hinge connected to said arms forwardly of said rearward ends by respective second hinge connections so as to be pivotable relative to said seat frame from a deployed position to a storage position by a pivoting movement towards said underside of said frame.

[0019] Yet another aspect of the invention provides a foldable wheelchair comprising a rear wheel frame, a seat frame hinge connected to said rear wheel frame by first hinge connections and a front wheel frame hinge connected to said seat frame by second hinge connections, wherein said rear wheel frame defines a back of said foldable wheelchair, said front wheel frame defines a front of said foldable wheel chair and said first and second hinges connections are configured such that said foldable wheel chair is collapsible from a use to a deployed condition by folding in a direction from said front to said back.

[0020] Still another aspect of invention provides a foldable wheelchair comprising a rear wheel frame, a seat frame, a front wheel frame, first and second rear wheels fitted to said rear wheel frame, first and second front wheels fitted to said front wheel frame, a seat back connected to said rear wheel frame at least one electric drive motor configured to drive said first and second rear wheels and at least one battery pack connected with said at least one electric drive motor, wherein said at least one battery pack is disposed in a compartment provided on a rearward face of said seat back.

[0021] Yet another aspect of the invention includes a method of folding a foldable wheelchair that comprises a rear wheel frame, a seat frame and a front wheel frame, said method comprising pivoting said front wheel frame relative to said seat frame and pivoting said seat frame relative to said rear wheel frame such that said front wheel frame and seat frame each move towards said rear wheel frame so that a length of said foldable wheelchair defined by a spacing between said rear wheel frame and said front wheel frame is reduced.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order that the invention may be well understood, some embodiments thereof, which are given by way of example only, will now be described with reference to the drawings in which:

[0024] FIG 1 is a schematic diagram of an embodiment of a foldable wheelchair according to an embodiment of the invention;

[0025] FIG 2 is a schematic diagram of the frame and locking mechanism of the foldable wheelchair of FIG 1 ;

[0026] FIG 3 is an enlargement of the portion that is circle in FIG 2;

[0027] FIG 4 is a perspective view of a part of a locking mechanism of the foldable wheelchair of FIG 1.

[0028] FIG 5 is a perspective view of another embodiment of a foldable wheelchair;

[0029] FIG 6 is a rear view of the foldable wheelchair of FIG 6;

[0030] FIG 7 is a schematic illustration of the wheelchair in the unfolded use condition shown in FIG 5;

[0031] FIG 8 is a schematic illustration corresponding to FIG 7 showing the foldable wheelchair in a folded non-use condition; FIG 9 is a schematic illustration of a removable push handle for a foldable wheelchair as shown in FIGS 1 to 4 or FIGS 5 to 8;

[0032] FIG 10 is a schematic illustration of a removable seat back for a foldable wheelchair as shown in FIGS 1 to 4 or FIGS 5 to 8;

[0033] FIG 11 is a schematic front view of a battery compartment for a foldable wheelchair as shown in FIGS 1 TO 4 or FIGS 5 to 8; and

[0034] FIG 12 is a schematic side view of the battery compartment shown in FIG 11.

[0035] DETAILED DESCRIPTION

[0036] Referring to Figures 1 and 2, an embodiment of a foldable wheelchair comprises a rear wheel frame 1, a seat frame 2, a front wheel frame 3, armrest frames 4, an oblique connecting rod 5 and a locking mechanism 6. The front wheel frame 3 is hinged to the underside of the seat frame 2, the rear side of the seat frame 2 is hinged to the middle of the rear wheel frame 1, the armrest frames 4 are hinged to the rear wheel frame 1 and the seat frame 2, a first end of the oblique connecting rod 5 is hinged to the front wheel frame 3 at a first position and a second end of the oblique connecting rod 5 is hinged to the rear wheel frame 1 at a second position The vertical height of the hinge point between the oblique connecting rod 5 and the front wheel frame 3 is higher than the vertical height of the hinge point between the oblique connecting rod 5 and the rear wheel frame 1.

[0037] Referring to Figures 3 and 4, the locking mechanism 6 includes first and second movable plates 61, a connecting beam 62 and a tension spring 63. The first and second movable plates 61 are hinged to the seat frame 2 and are connected to respective ends of the connecting beam 62. A first end of the tension spring 63 is fixed to the first movable plate 61 and a second end of the tension spring 63 is fixed to the seat frame 2. The side of the movable plate 61 closest to the tension spring 63 faces inwardly of the seat frame 2 and front wheel frame 3 and the opposite side of the movable plate 61 is against the seat frame 2 and the front wheel frame 3. The upper end of the front wheel frame 3 abuts the underside of the seat frame 2 when the foldable wheelchair is in an unfolded use condition, as shown in Figures 1 to 3.

[0038] By arranging the front wheel frame 3 to be hinged to the seat frame 2, the seat frame 2 to be hinged to the rear wheel frame 1 , the armrest frame 4 to be hinged to the rear wheel frame 1 and the seat frame 2, and the oblique connecting rod 5 to be hinged to the front wheel frame 3 and the rear wheel frame 1, the front wheel frame 3, the seat frame 2 and the armrest frame 4 can be folded toward the rear wheel frame 1 as a whole, and a stable wheelchair structure is formed when unfolded. The wheelchair can be folded or unfolded without complicated steps, thereby improving the convenience of use. The movable plate 61, the tension spring 63 and the oblique connecting rod 5 not only provide a reliable locking function, but also effectively prevent the wheelchair from accidentally folding during use, thereby greatly reducing the safety hazard to the user.

[0039] Referring to Figures 3 and 4, the locking mechanism 6 also includes a first locking pin 21 and a second locking pin 33. The first locking pin 21 is arranged on the inner side of the seat frame 2 and the second locking pin 33 is arranged on the inner side of the front wheel frame 3. The first movable plate 61 abuts the first locking pin 21 and the second locking pin 33 when the locking mechanism is in a locking condition.

[0040] By arranging the first locking pin 21 on the seat frame 2 and the second locking pin 33 on the front wheel frame 3, locking points with the seat frame 2 and the front wheel frame 3 are provided for the first movable plate 61. When the wheelchair is unfolded for use, the first movable plate 61 maintains contact with the first locking pin 21 and the second locking pin 33, so that the locking mechanism 6 can keep the seat frame 2 and the front wheel frame 3 locked, effectively preventing the wheelchair from accidentally moving or folding when in a folded or unfolded state.

[0041] Furthermore, a protruding limiting portion 611 and a hook-shaped limiting portion 612 are respectively disposed adjacent the upper and lower ends of the first movable plate 61 near the tension spring 63. The protruding limiting portion 611 and the hook-shaped limiting portion 612 respectively abut the first locking pin 21 and the second locking pin 33 when the locking mechanism is in the aforementioned locking condition.

[0042] By arranging a protruding limiting portion 611 and a hook-shaped limiting portion 612 on the first movable plate 61, it is ensured that the first movable plate 61 can engage the first locking pin 21 and the second locking pin 33 at the same time. By the abutment between the protruding limiting portion 611 and the first locking pin 21 and the abutment between the hookshaped limiting portion 612 and the second locking pin 33, the movable plate 61 maintains abutment with the seat frame 2 and the front wheel frame 3 when the wheelchair is unfolded for use, ensuring that the wheelchair will not accidentally fold or slide during use.

[0043] Referring to Figure 2, the foldable wheelchair preferably also includes a first connecting member 7. A first positioning groove 71 matching the bottom of the seat frame 2 is formed at the top of the first connecting member 7. The top of the first connecting member 7 is connected to the seat frame 2. A hinge shaft is formed at the botom of the first connecting member 7, a second positioning groove 31 matching the bottom of the seat frame 2 is formed at the top of the front wheel frame 3. Both the first positioning groove 71 and the second positioning groove 31 are fitted with the botom of the front wheel frame 3. A connecting portion 32 is provided on one side of the front wheel frame 3 and is hinged to the first connecting member 7 by a hinge shaft.

[0044] The first connecting member 7, the seat frame 2 and the front wheel frame 3 are hinged by the first connecting member 7, so that when the wheelchair is unfolded for use, the second positioning groove 31 on the top of the front wheel frame 3 fits with the bottom of the seat frame 2, increasing the contact area and stability between the seat frame 2 and the front wheel frame. This makes the wheelchair more stable during use. By providing the first positioning groove 71 on the first connecting member 7, the contact area between the first connecting member 7 and the seat frame 2 is increased. When the first connecting member 7 is connected to the seat frame 2, rivets or bolts can be used to pass through the first positioning groove 71 and the seat frame 2 to achieve connection, thereby improving the stability of the connection.

[0045] Referring to Figure 3, the locking mechanism 6 preferably further includes a first fixing bolt 64 and a second fixing bolt 65. One end of the tension spring 63 is fixed to the movable plate 61 through the first fixing bolt 64 and the other end of the tension spring 63 is fixed to the first connecting member 7 through the second fixing bolt 65. The second fixing bolt 65 is coaxially arranged with the hinge axis. By arranging the first fixing bolt 64 and the second fixing bolt 65, the two ends of the tension spring 63 are fixed.

[0046] Referring to Figure 2, the seat frame 3 preferably includes two second connecting members 8 and a reinforcing beam 81. The two second connecting members 8 are arranged on the left and right sides of the middle part of the rear wheel frame 1. The two ends of the reinforcing beam 81 are respectively connected to the two second connecting members 8. One end of each second connecting member 8. is connected to the rear wheel frame 1 and the other end of each second connecting member 8 extends forward and is hinged to the seat frame 2.

[0047] By arranging the second connecting members 8 on the left and right sides of the rear wheel frame 1 and arranging a reinforcing crossbeam 81 between the two second connecting members 8, the overall structural strength of the rear wheel frame 1 is improved, making the wheelchair more stable and durable during use. Since the second connecting members 8 extend forward, the arrangement of the second connecting members 8 also enables the seat frame 2 to fit more closely to the rear wheel frame 1 when folded, reducing the volume after folding and further optimizing the space utilization.

[0048] Preferably, each armrest frame 4 includes an armrest rod 41 , a third connecting member 42 and a support rod 43. One end of the armrest rod 41 is hinged to the rear wheel frame 1, one end of the support rod 43 is hinged to the seat frame 2 and the third connecting member 42 is hinged to the other end of the support rod 43 and the bottom of the armrest rod 41 A third positioning groove 421 matching the bottom of the armrest frame 4 is provided at the top of the third connecting member 42 and is in contact with the bottom of the armrest rod 41.

[0049] By having one end of the armrest rod 41 hinged to the rear wheel frame 1 , one end of the support rod 43 hinged to the seat frame 2, and the third connecting member 42 hinged to the armrest rod 41 and the support rod 43 respectively, the armrest frame 4 as a whole can be folded in the direction of the rear wheel frame 1 when the wheelchair is folded. When the wheelchair is in the unfolded state, the armrest rod 41, the third connecting member 42 and the support rod 43 form a stable structure under the action of the seat frame 2, thereby improving the stability of the armrest frame 4. By providing a third positioning groove 421 matching the bottom of the armrest rod 41 at the top of the third connecting member 42 that fits with the bottom of the armrest rod 41 , when the wheelchair is unfolded and used, the contact area between the handrail rod 41 and the third connecting member 42 is increased, thereby further improving the structural stability.

[0050] Preferably, a footrest 12 is further included, and the front wheel frame 3 is provided with a footrest support rod 13 extending downward. The footrest 12 is hinged to the footrest support rod 13. By providing the footrest 12, a comfortable foot support can be provided for the user. Having the footrest 12 and the footrest support rod 13 hinged to the front wheel frame 3, the footrest 12 can be folded with the front wheel frame 3, further reducing the space occupied by the foldable wheel chair.

[0051] Preferably, the foldable wheelchair also includes a front wheel assembly 91 , a rear wheel assembly 92, a seat cushion 93, a back cushion 94 and an armrest pad 95. The front wheel assembly 91 is arranged at the bottom of the front wheel frame 3 and the rear wheel assembly 92 is arranged at the bottom of the rear wheel frame 1. The back cushion 94 covers the middle and upper part of the rear wheel frame 1 and covers the seat frame 2, and the armrest pad 95 covers the armrest frame 4.

[0052] Preferably, the front wheel assembly 91 is rotatably connected to the bottom of the front wheel frame 3. By setting the rotatable connection between the front wheel assembly 91 and the front wheel frame 3, the angle of the front wheel assembly 91 can be adjusted when folding, so that the front wheel fits more closely to the seat frame 2, further reducing the overall space occupied after folding.

[0053] The working principle of this embodiment is as follows. The foldable wheelchair of this embodiment has two states: unfolded and folded. When unfolded, the frames are unfolded to form the wheelchair use structure shown in Figures 1 and 2. Once fully unfolded, the movable plates 61 are kept in contact with the seat frame 2 and the front wheel frame 3 under the elastic force of the tension spring 63, so as to lock the seat frame 2 and the front wheel frame 3. At the same time, the oblique connecting rod 5 forms a stable structure with the seat frame 2 and the rear wheel frame 1 , avoiding the safety hazard caused by the wheelchair folding due to sudden unlocking during use.

[0054] When folding, the tension spring 63 is stretched by pulling the connecting beam 62, so that the protruding limiting portion 611 is separated from the first locking pin 21 and the hookshaped limiting portion 612 is separated from the second locking pin 33, so that the locking mechanism 6 as a whole is away from the seat frame 2 and the front wheel frame 3, and the seat frame 2 and the front wheel frame 3 are unlocked, so that the front wheel frame 3 can be folded toward the seat frame 2, the seat frame 2 can be folded toward the rear wheel frame 1, and the armrest frame 4 can be folded toward the rear wheel frame 1, thereby realizing the overall folding of the wheelchair, which is easy to operate.

[0055] Figures 5 to 8 show an embodiment of a foldable wheelchair 110 that is constructed and operates in at least similar fashion to the foldable wheelchair illustrated by Figures 1 to 4. The foldable wheelchair 110 comprises a main frame that comprises a front wheel frame 112, a rear wheel frame 114 and a seat frame 116. The front wheel frame 112, rear wheel frame 114 and seat frame are hinge connected so such that the foldable wheelchair can be folded between the use and non-use conditions with a front to back movement that involves the seat frame 116 pivoting upwardly from a hinge connection with the rear wheel frame 114 and the front wheel frame 112 pivoting from a hinge connection with the seat frame with a movement towards the underside of the seat frame and the rear wheel frame.

[0056] The front wheel frame 112, rear wheel frame 114 and seat frame 116 may be made of a suitable metal material. In some embodiments, the frame members are made of magnesium alloy.

[0057] The front wheel frame 112 comprises oppositely disposed upright members 118, 120 that are connected at respective lower ends thereof by a cross-member 122. The position of the cross member 122 may be such that the front wheel frame has a generally U-shaped configuration. The upper end of each upright member 118, 120 is contoured to match the underside of the seat frame 116 so that when the front wheel frame 112 is deployed in the unfolded use condition of the foldable wheelchair, the upper ends of the upright members 118. 120 fit snugly against the underside the seat frame. The contouring may take the form of a channel or groove configured to conform to the contours of the portion of the seat frame 116 that is engaged by the upper ends of the upright members 118, 120.

[0058] The upright members 118, 120 are connected with the seat frame 116 by respective connecting members 124 (only one of which is visible in Figures 5 to 8). Each connecting member 124 comprises a generally U-shaped body defining a channel that is open at an upper end and configured to at least partially receive the seat frame 116 by moving the connecting member against the seat frame from below so that a part of the seat frame is received in the channel. The connecting member 124 is secured to the seat frame 116 by bolts, screws, rivets or the like that extend through the seat frame and the opposed sides of the U-shaped connecting member. Each upright member 118, 120 is provided with a connecting link 126 that is fixed to the upright member adjacent the upper end of the upright member and extends towards the rear wheel frame 114. The connecting links 126 are hinge connected to the respective connecting members 124 by respective pivot shafts 128 that pass through the connecting members 124 and connecting links 126 and are secured to the connecting members. The hinge connection between the seat frame 112 and the seat frame 116 provided by the connection of the connecting members 124 and connecting links 126 via the hinge shafts 128 enables relative pivoting movement of the front wheel frame and seat frame, so that the front wheel frame 112 can be moved from the deployed position shown in Figures 5 and 7 towards the underside of the seat frame to a folded position as shown in Figure 8. The rear wheel frame 114 comprises upright members 136, 138 that are connected by a lower cross member 140 and an upper cross member 142. Respective connecting members 144 are fixed to the upright members 136, 138 and extend forwardly from the rear wheel frame 114 towards the front wheel frame 112. A reinforcing rod 146 extends between and is secured to the connecting members 144 at a position intermediate the cross members 140, 142. The seat frame 116 has a generally U-shaped configuration with a transverse member at the front and respective arms 148 extending in spaced apart relation from the ends of the transverse member towards the rear wheel frame 114. The seat frame 116 may be a one-piece structure or comprise a plurality of members fixed to one another. The free ends of the arms 148 are hinge connected to the respective connecting members 144 by respective hinge shafts 150 that extend through the connecting members and the free ends of the arms. The hinge connection of the seat frame 116 to the rear wheel frame 114 is configured so that the seat frame can pivot anti-clockwise (as viewed in Figure 7 and 8) to move the upper side of the seat frame towards the rear wheel frame.

[0059] The front wheel frame 112 and rear wheel frame are connected by an oblique connecting rod, or bar, 154. The oblique connecting rod 154 is connected to the front wheel frame 112 at a first position by a hinge shaft 156 and to the rear wheel frame 114 at a second position by a hinge shaft 158. The first position is higher than the second position so that the oblique connecting rod 154 slopes downwardly from its connection point with the front wheel frame 112 towards its connection point with the rear wheel frame 114. The oblique connecting rod 154 aids in stiffening the main wheel chair frame when the foldable wheelchair 110 is in an unfolded use condition as shown in Figures 5 to 7. It will be understood that while only the illustrated embodiments are shown with just one oblique connecting rod, in other embodiments, there may be two oblique connecting rods, one on each side of the foldable wheelchair.

[0060] The foldable wheelchair 110 is provided with a locking mechanism that corresponds to the locking mechanism illustrated in Figures 1 to 4 and avoid to repetition of description will not be described in further detail herein.

[0061] The foldable wheelchair 110 is provided with left and right armrests 166 that are each hinge connected with the rear wheel frame 114 and the seat frame 116. At best seen in Figure 7, each armrest comprises an armrest frame comprising an armrest rod 168, a support rod 170 and a connecting member 172. The armrest rod 168 is hinged at a rearward end to a respective upright member 136, 138 by a hinge shaft 174 configured so that the armrest rod can pivot relative to the upright member. A lower end of each support rod 170 is hinged to a respective arm 148 of the seat frame 116 by a respective hinge shaft 176 configured so that the support rod can pivot relative to the seat frame. Forwardly of the rearward end each armrest rod 168 is hinged to a rearward end of the respective connecting member 172 by a hinge shaft 180 and an upper end of each support rod 170 is hinged to a forward end of a respective connecting member 172 by a hinge shaft 182. The top side of each connecting member 172 is contoured to receive an underside of the respective armrest rod 168 to provide a stable seat and support for the armrest rod. The configuration of the armrests 166 is such that when the foldable wheelchair 110 is moved from the unfolded use condition shown in Figures 5 to 7 to the folded non-use condition shown in Figure 8, the armrest rods 168 and the support rods 170 can pivot towards the rear wheel frame 114 (clockwise as viewed in Figures 7 and 8). Furthermore, the armrest rods 168 can pivot relative to the connecting members 172 on hinge shafts 180 so that they can move to a position closer to, or even rearwardly of, the rear wheel frame 114.

[0062] The foldable wheelchair 110 may be provided with a footrest assembly 180, which may be similar to or the same as the footrest assembly shown in Figure 2. Specifically, the footrest assembly 180 may comprise a footrest support structure that may comprise a footrest support rod 182 fixed to and depending from the cross member 122. The footrest assembly 180 may further comprise one or more footrests 184 hinge connected to the free end of the footrest support rod 182. In the illustrated embodiment, there is one footrest 184, which is configured to support both feet of a user of the foldable wheelchair 110. Although not preferred, in other embodiments there may be separate footrests connected to the footrest support rod, one for each foot, or even respective footrest support rods for separate footrests. In the illustrated embodiment, the footrest 184 slopes downwardly towards the footrest support rod 182 and is provided with a heel rest 186. The heel rest 186 comprises an upstanding wall disposed at the rear of the footrest 184 adjacent the hinge connection with the footrest support rod 182 and is configured to prevent the user’s feet from sliding rearwardly off of the footrest. The hinge connection of the footrest 184 with the footrest support rod 182 is such that when not wanted or when the foldable wheelchair 110 is folded for storage or the like, the footrest 184 can pivot towards the footrest support rod 182. A latch system (not shown) may be provided to maintain the footrest in a non-deployed, or folded, condition.

[0063] The upright members 136, 138 of the rear wheel frame 114 are each provided with a push handle 190. The push handles 190 may be removable or fixed to the respective upright members 136, 138. The illustrated embodiment has removable push handles 190 that can be detached from the upright members 136, 138 when the foldable wheelchair is in a folded condition to further reduce the space required to store the foldable wheelchair or during shipping. Figure 9 shows an example of removable push handles 190 that are provided with screw threads 192 configured to mate with screw threads 194 provided at the upper ends of the upright members 136, 138. The screw threads 192 on the push handles 190 may be male threads configured to screw into female threads 194 provided in the upper ends of the upright members 136, 138 or vice versa. The push handles 190 may comprise a metal, for example chrome plated steel, tube 196 with the screw thread 192 provided at one end of the tube. A grip 198 may be fitted onto the tube and extend from the opposite end towards the screw thread 192. The grip 198 may be made of any suitable material, such as a rubber or rubber-like material. Although a threaded connection of the push handles 190 with the upright members 136, 138 is currently preferred, it will be appreciated that other retaining systems may be used. For example, the push handles 190 may be a push fit into the upper ends of the upright members 136, 138 and be retained by respective releasable locking devices comprising spring-loaded rods that engage recesses or apertures provided in the push handles and are actuable by respective push buttons provided accessible at the outside of the upright members 118, 120.

[0064] The front wheel frame 112 is provided with respective front wheel assemblies 198 fitted to the lower ends of the upright members 118, 120. The front wheel assemblies 198 each comprise a front wheel 200 and a bearing assembly (not shown) that enables the front wheel to rotate around a generally vertical axis to allow the foldable wheelchair 110 to be steered in a conventional manner. Steering front wheels for wheelchairs and the means for enabling rotation of the front wheels with respective to a wheelchair frame will be known to the skilled person and so will not be described in further detail herein.

[0065] The upright members 136, 138 of the rear wheel frame 114 are provided with respective rear wheel assemblies 202 that each comprise a wheel 204 that is mounted on a fixed axle (not shown) that is fixed to or adjacent the lower ends of the upright members 136, 138. The upright members 136, 138 are further provided with respective anti-tip wheels 206 that are supported by respective support arms 208 that are connected with the upright members 136, 138. The support arms 208 may be releasably connected with the rearward faces of the upright members 136, 138. For example, the free ends of the support arms 208 may be insertable in apertures provided in the upright members 136, 138 and locked in place by spring loaded rods that engaged in recesses or apertures provided in the support arms and actuable by respective push buttons accessible at the outside of the rear wheel frame 114.

[0066] Each of the rear wheel assemblies 202 is provided with an electric drive motor 210 that is supported by the rear wheel frame 114 and configured to power the respective rear wheel 204. The electric motors 210 are powered by an electric power supply provided on the rear seat, as will be described in more detail below. The electric drive motors 210 may be fitted with respective lever actuators 211 that are movable between a first position in which the electric drive motors are enabled to drive the rear wheel assemblies 202 and a second position in which the electric drive motors are disengaged to enable the foldable wheelchair to be used in free wheel mode. Although separate electric drive motors for the rear wheel assemblies are currently preferred, in some embodiments, a single drive motor may be provided with suitable gearing to enable it to drive both rear wheel assemblies.

[0067] The seat frame 114 is provided with a seat 216 that is disposed on the seat frame. The seat 216 may be secured to the seat frame 114 by a hook and loop fastener system such as Velcro® so that the seat can be quickly and easily removed for cleaning or exchange with another seat. The forward end of the seat 216 may be provided with one or more securing loops 218 configured to loop around the forward end of the seat frame 114 and secure to the underside of the seat 216 by means of a hook and loops system, press studs or any other suitable fastening arrangement.

[0068] The foldable wheel chair 110 may be provided with a seat belt arrangement 220 that is secured to the rear wheel frame 114 or the seat frame 114.

[0069] The foldable wheel chair 110 further comprises a seat back 226 that is secured to and supported by the rear wheel frame 114. Referring to Figure 10, the seat back 226 may be connected with respective side members 228 by relatively narrow connecting elements 230. The side members 228, which may be circular section rods, are configured to be push-fitted into engagement with complementary engagement members 232 provided on the upright members 136, 138. In the illustrated embodiment, the engagement members are oppositely disposed channel members provided on the upright members 136, 138 that define respective slots 234 to receive the side members 228. The channel members 232 may have an arcuate cross section that defines a partial circle that is open on one side to define a lengthways extending opening 236 configured to receive the connecting elements 230. In some embodiments, the side members 228 may extend along at least a substantial portion of the length of the sides of the seat back 226. The channel members 232 may be the same length of at least similar in length to the side members 228 so that when the side members are fitted in the respective slots 234, there is at least substantially continuous support for the sides of the seat back 226 along their entire length. In other embodiments, each side of the seat back 226 may be provided with a plurality of relatively shorter side members 228. In yet other embodiments, the upright members 136, 138 may be provided with a plurality of relatively shorter channel members 232 disposed at spaced apart intervals. It will be understood that in some embodiments, relatively shorter side members 228 may be used in conjunction with relatively shorter channel members 234 while in other embodiments, relatively shorter side members 228 may be used with channel members that extend along at least a substantial portion of the length of the sides of the seat back 226 and vice versa. It will also be understood that while in the illustrated embodiment the side members 228 on the sides of the seat back 226 are male parts that sit into female engagement members 232 provided on the upright members 136, 138, in other embodiments, the side members on the seat back 226 may be configured as female parts that are able to receive male members provided on the upright members 136, 138. In either case, the seat back 226 can be fitted to the rear wheel frame 114 by inserting the seat back between the upright members 136, 138 and causing a relative sliding movement between the side members on the seat back and the engagement members on the upright members.

[0070] The seat back 226 may comprise a padded body covered by a suitable fabric. Stiffening members, for example plastics plates or rods may be provided within the seat back to provide a relatively rigid non-collapsible seat back that may be contoured to provide desired back support for the user. This may be advantageous for at least some users when compared with conventional wheelchairs that have a seat back that is essentially a piece of fabric connected between the opposite sides and is made possible by the front to back folding characteristic of the foldable wheelchair and is not readily achievable with conventional foldable wheelchairs that fold, or collapse from side to side.

[0071] The rearward face of the seat back 226 may be provided with a compartment 250 to house at least a battery pack 252 used to power the electric drive motors 210. The battery pack 252 may comprise a plurality of lithium-ion cells.

[0072] In the embodiment illustrated by Figures 5 to 8, 11 and 12, the compartment 250 also houses a controller 254. The controller 254 is connected to the battery pack 252 by a plug 256 and electric cable 258. The compartment 250 may be a fabric bag-like constructed secured to the seat back 226 by stitching or the like. The compartment 250 comprises opposed side walls 260, a bottom wall 262 and a top wall 264. The top and bottom walls 262, 264 extend beyond the side walls 260. A front wall 266 extends between the side walls 260 from the bottom wall 262. An upper portion of the front wall 266 is detached from and releasably connected to at least the side walls 260 and the top wall 264 to define an opening 268 and flap 270. The flap 270 can be secured in place closing the opening 268 by any convenient known means such as one or more toggles, press studs or buttons. In the illustrated embodiment, the flap 270 is securable to the side walls 260 and top wall 264 by a zipper system 272 to close the opening 268. Suitable apertures are provided in the walls of the compartment to allow electric cables to be run to the electric drive motors 210 and a joystick controller 274 mounted on one of the armrest frames and to an optional controller 276 mounted on the upper cross member 142. In some embodiments, the joystick controller 274 may be mounted on an arm that is removably connected with a receptacle provided on an armrest frame such that the joystick controller can be moved back and forth to adjust its position relative to the armrest frame. Similarly, the controller 276 may be removably connected to the upper cross member 242.

[0073] The walls of the compartment 250 may be made of any suitable sheet material such as an organic or inorganic fabric or plastics sheet. The walls may comprise an outer layer and an inner lining and card or plastics stiffeners may be provided between the outer layer and the inner lining. Alternatively, or in addition, reinforcing ribs, for example comprised of plastics rod, may be sewn into the outer edges of the walls or the flap.

[0074] Moving the battery pack 252 to a relatively elevated position on the seat back 226 provides convenient access for users. Furthermore, locating the battery pack 252 in a bag-like compartment 250 removes the need to fix the battery pack in position, on a frame member of the foldable wheelchair so that it can be removed from the wheelchair for charging by simply disconnecting the plug 256 and lifting the battery pack from the compartment 250. Although the battery pack 252 may conveniently be removed from the compartment 250 for charging, in some embodiments, one or more of the joystick controller 274 and, when provided, the controller 276 may be provided with a charging port to enable onboard charging of the battery pack 252. The technical principle of the present invention is described above in combination with specific embodiments. That description is only for explaining the principles of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the scope of the present invention, which is limited only by the appended claims.

Claims

1. Claims1. A foldable wheelchair comprising a rear wheel frame, a seat frame, a front wheel frame, two armrest frames, an oblique connecting rod and a locking mechanism, wherein the front wheel frame is hinged to an underside of the seat frame, a rear side of the seat frame is hinged to the rear wheel frame, the armrest frames are each hinged to the rear wheel frame and the seat frame, a first end of the oblique connecting rod is hinged to the front wheel frame at a first position and a second end of the oblique connecting rod is hinged to the rear wheel frame at a second position, wherein said first position at which the first end of the oblique connecting rod is hinged to the front wheel frame is higher than said second position at which the second end of the oblique connecting rod is hinged to the rear wheel frame, wherein the locking mechanism includes a connecting beam having a first end and a second end, a first movable plate connected to said first end of the connecting beam and a second movable plate connected to said second end of the connecting beam and a tension spring, wherein the first and second movable plates are hinged to respective sides of the seat frame, a first end of the tension spring is fixed to said first movable plate, a second end of the tension spring is fixed to the seat frame, the side of the first movable plate closest to the tension spring faces away from the respective side to which it is hinged, and an upper end of the front wheel frame abuts said underside the seat frame when the foldable wheelchair is in an unfolded use condition.

2. The foldable wheelchair according to claim 1, wherein the locking mechanism further comprises a first locking pin and a second locking pin, the first locking pin is arranged on an inner side of the seat frame, the second locking pin is arranged on an inner side of the front wheel frame and said first movable plate abuts the first locking pin and the second locking pin when said locking mechanism is in a locking condition.

3. The foldable wheelchair according to claim 2, wherein said first movable plate is provided with a protruding limiting portion and a hook-shaped limiting portion that are respectively disposed adjacent an upper end and a lower end of the first movable plate, and wherein the protruding limiting portion and the hook-shaped limiting portion respectively abut the first locking pin and the second locking pin when said locking mechanism is in said locking condition.

4. The foldable wheelchair according to claim 1, 2 or 3, further comprising a first connecting member, wherein an upper end of the first connecting member is provided with a first positioning groove configured to match said underside of the seat frame, the upper end of the first connecting member is connected to the seat frame, a lower end of the first connecting member is provided with a hinge shaft, said upper end of the front wheel frame is provided with a second positioning groove configured to match said underside of the seat frame, the first positioning groove and the second positioning groove are both in contact with said underside of the seat frame when said foldable wheelchair is in said unfolded use condition, a connecting portion is provided on one side of the front wheel frame, and the connecting portion is hinged to the first connecting member by the hinge shaft.

5. The foldable wheelchair according to claim 4, wherein the locking mechanism further includes a first fixing bolt and a second fixing bolt, said first end of the tension spring is fixed to the first movable plate via the first fixing bolt, said second end of the tension spring is fixed to seat frame via the first connecting member and the second fixing bolt, and the second fixing bolt is coaxially arranged with the hinge shaft.

6. The foldable wheelchair according to any one of the preceding claims, wherein the rear wheel frame comprises a left side second connecting member connected at a first end to a left side of said rear wheel frame, a right side second connecting member connected at a first end to a right side of said rear wheel frame and a reinforcing cross beam having respective ends connected to the left side second connecting member and the right side second connecting member, and wherein respective second sends of said left side second connecting member and said right side second connecting member are disposed forwardly of the rear wheel frame and the seat frame is hinged to the rear frame via said second ends of the left side second connecting member and the right side second connecting member.

7. The foldable wheelchair according to any one of the preceding claims, wherein each armrest frame includes an armrest rod, a third connecting member and a support rod, a first end of the armrest rod is hinged to the rear wheel frame, a first end of the support rod is hinged to the seat frame, the third connecting member is hinged to a second end of the support rod and anunderside portion of the armrest rod, a topside of the third connecting member is provided with a third positioning groove configured to match said underside portion of the armrest frame, and the third positioning groove is in contact with said underside portion of the armrest frame when the foldable wheelchair is in said unfolded use condition.

8. The foldable wheelchair according to any one of the preceding claims, further comprising a footrest, wherein the front wheel frame is provided with a footrest support rod extending downwards and the footrest is hinged to the footrest support rod.

9. The foldable wheelchair according to claim any one of the preceding claims, further comprising a front wheel assembly, a rear wheel assembly, a seat cushion, a back cushion and two armrest pads, wherein the front wheel assembly is arranged at a lower end of the front wheel frame, the rear wheel assembly is arranged at a lower end of the rear wheel frame, the back cushion is fitted against an upper and middle part of the rear wheel frame, the seat cushion is disposed on the seat frame, and the armrest pads are fitted to respective said armrest frames.

10. The foldable wheelchair according to claim 9, wherein the front wheel assembly is rotatably connected to the lower end of the front wheel frame.

11. The foldable wheelchair according to any one of the preceding claims, further comprising at least one removable push handle fitted to said rear wheel frame.

12. The foldable wheelchair according to any one of the preceding claims, further comprising a seat back and a battery power pack carried in a compartment provided on a rearward face of said seat back.

13. The foldable wheelchair according to claim 12, wherein said seat back is configured to be push-fit connected to said rear wheel frame.

14. The foldable wheelchair according to claim 13 or 14, wherein said seat back has a first side and a second side that define a width of said seat back and said seat back is at least substantially rigid and non-collapsible between said first side and said second side.

15. A foldable wheelchair comprising a rear wheel frame, a seat frame, a front wheel frame and at least one connecting rod connected to said rear wheel frame and said front wheel frame, wherein said seat frame comprises a forward end, an underside and two oppositely disposed arms extending rearwardly with respect to said forward end and having rearward ends hinge connected to said rear wheel frame by respective first hinge connections so that said seat frame is pivotable relative to said rear wheel frame from deployed position to a storage position in which said forward end is disposed closer to said rear wheel frame than when said seat frame is in said use position by a pivoting movement that is upwards and towards said rear wheel frame, and wherein said front wheel frame is hinge connected to said arms forwardly of said rearward ends by respective second hinge connections so as to be pivotable relative to said seat frame from a deployed position to a storage position by a pivoting movement towards said underside of said frame.

16. The foldable wheelchair according to claim 15, further comprising first and second rear wheels fitted to said rear wheel frame and first and second front wheels fitted to said front wheel frame, wherein in said first and second hinge connections are configured such that in said deployed positions of said front wheel frame said seat frame said front wheels and said rear wheels are disposed in a common plane to support said foldable wheelchair and in said storage positions of said front wheel frame and said seat frame said front wheels are disposed in an elevated position relative to said rear wheels.

17. The foldable wheelchair according to claim 15 or 16, further comprising at least one removable push handle secured to said rear wheel frame by screw threading or a releasable locking device.

18. The foldable wheelchair according to claim 15, 16 or 17, further comprising a seat back and a battery power pack carried in a compartment provided on a rearward face of said seat back.

19. The foldable wheelchair according to claim 18, wherein said compartment comprises flexible wall members secured to said seat back and a flap securable to at least one said flexible wall member to close an opening defined by said flexible wall members.

20. The foldable wheelchair according to claim 18 or 19, wherein said seat back is relatively rigid and non-collapsible in a widthways direction thereof.

21. The foldable wheelchair according to claim 18, 19 or 20, wherein said seat back comprises respective sides provided with side members that project from said sides and are engageable with complementary engagement members provided on said rear wheel frame.

22. The foldable wheelchair according to claim 21, wherein said side members and complementary engagement members are configured to enable removable fitting of said seat back to said rear wheel frame by push-fitting.

23. The foldable wheelchair of any one of claims 15 to 21, further comprising a locking mechanism for locking said front wheel frame to said seat frame in said deployed position of said front wheel frame, said locking mechanism comprising a locking member pivotally mounted on said seat frame for rotation about an axis of rotation, a first locking element provided on said seat frame, a second locking element provided on said front wheel frame and a biasing element connected to said seat frame and said locking member, wherein said locking member is biased into engagement with said first and second locking elements by said biasing element to prevent movement of said seat frame from said deployed position.

24. The foldable wheelchair according to claim 23, wherein said locking member is provided with respective projections for engaging said first and second locking elements and said biasing element is configured to bias said in a first pivoting direction to cause said projections to engage said first and second locking elements.

25. The foldable wheelchair according to claim 23 or 24, comprising two said locking mechanisms and a cross-member connecting the respective locking members thereof whereby said locking members can be simultaneously pivoted in a second pivoting direction that is opposite said first pivoting direction by movement of said cross-member relative to said seat frame and said front wheel frame.

26. A foldable wheelchair comprising a rear wheel frame, a seat frame, a front wheel frame,first and second rear wheels fited to said rear wheel frame, first and second front wheels fitted to said front wheel frame, a seat back connected to said rear wheel frame at least one electric drive motor configured to drive said first and second rear wheels and at least one battery pack connected with said at least one electric drive motor, wherein said at least one battery pack is disposed in a compartment provided on a rearward face of said seat back.

27. The foldable wheelchair according to claim 26, wherein said seat back has a first side and a second side defining a width of said seat back and is configured to be at least substantially rigid and non-collapsible in a direction from said first side to said second side.

28. The foldable wheelchair according to claim 26, wherein said first and second sides are provided with projecting side members that are engageable with complementary engagement members provided on said rear wheel frame and configured to enable removable fitting of said seat back to said rear wheel frame by push- fitting.

29. The foldable wheelchair according to claim 26, 27 or 28, wherein said seat frame is connected with said rear wheel frame by first hinge connections and said front wheel frame is connected with said seat frame by second hinge connections, said first and second hinge connections being configured such that said foldable wheelchair is foldable from a deployed condition to a storage position by movement of said front wheel frame towards said rear wheel frame.

30. The foldable wheelchair according to claim 29, wherein said first and second hinge connections are configured such that in said deployed condition said front wheels and said rear wheels are disposed in a common plane to support said foldable wheelchair and in said storage condition said front wheels are disposed in an elevated position relative to said rear wheels.

31. The foldable wheelchair according to any one of claims 26 to 30, wherein said compartment comprises flexible wall members secured to said seat back and a flap securable to at least one said flexible wall member to close an opening defined by said flexible wall members.

Images