GB2317861A

GB2317861A - Wheelchair

Info

Publication number: GB2317861A
Application number: GB9718778A
Authority: GB
Inventors: Roy Macnaugton; Martin Peter Moonie
Original assignee: Ross and Bonnyman Engineering Ltd
Current assignee: Ross and Bonnyman Engineering Ltd
Priority date: 1996-09-10
Filing date: 1997-09-05
Publication date: 1998-04-08
Also published as: GB9718778D0; GB9618840D0

Abstract

A wheelchair comprises a frame which is moveable between a collapsed position and an operating position, where the frame comprises a first side frame (a, b) and a second side frame which are connected by a hinge mechanism (20, 21). The hinge mechanism (20, 21) is coupled to the first side frame (a) at a first coupling point (11a) and to the second side frame (b) at a second coupling point (11b). The length of the hinge mechanism (20, 21) is adjustable such that when the wheelchair is in the operating position, the distance between the first coupling point (11a) and the second coupling point (11b) is adjustable to adjust the separation of the first (a) and second (b) side frames.

Description

"A Wheelchair" The invention relates to a wheelchair.

Conventionally, in order to ease transportation and storage of a wheelchair, it is known for wheelchairs to be collapsible. Hitherto, collapsible wheelchairs comprise diagonal tubes which connect one side of the wheelchair to the other side, and the diagonal tubes are attached pivotably to each other at their centre to permit the wheelchair to be folded. The folding diagonal tube arrangement has the disadvantage that there is no positive locking action, and the wheelchair is maintained in the in-use and operational position only by the weight of the user. Further, this conventional arrangement has the disadvantage that different widths of wheelchair are required depending on the size of the user. Also, this conventional arrangement requires a four-sided frame, or an upper and a lower tube, to mount the diagonal members.

Therefore, this traditional arrangement results in a relatively heavy wheelchair. Also, this traditional arrangement provides a structure for the wheelchair which is not particularly strong.

According to a first aspect of the present invention there is provided a wheelchair comprising a frame which is moveable between a collapsed position and an operating position, the frame comprising a first side frame and a second side frame, the two side frames being connected by a hinge mechanism, the hinge mechanism being coupled to the first side frame at a first coupling point and being coupled to the second side frame at a second coupling point, the length of the hinge mechanism being adjustable such that when the wheelchair is in the operating position, the distance between the first coupling point and the second coupling point is adjustable to adjust the separation of the first and second side frames.

Preferably, the hinge mechanism comprises a first and a second member, one end of the first member being coupled to the first side frame and one end of the second member being coupled to the second side frame.

Typically, the first and second members are pivotably coupled to each other.

Typically, the width of the wheelchair in the operating position is variable by varying the distance between the first or second coupling point and the pivotable coupling for at least one of the members. Typically, the members are pivotably coupled by a suitable bolting arrangement.

Preferably, the two side frames are connected by two hinge mechanisms.

Typically, the two hinge mechanisms are longitudinally spaced apart in the direction of movement of the wheelchair, and preferably, there is a front hinge mechanism and a rear hinge mechanism.

Preferably, the angle of the plane that one of the hinge mechanisms operates on is at an angle approximately 450 to the forward direction of movement of the wheelchair, and typically, the angle of the plane that the other of the hinge mechanisms operates on is at an angle approximately 450 to the reverse direction of movement of the wheelchair.

Typically, the one hinge mechanism is the rear hinge mechanism, and preferably, the other hinge mechanism is the front hinge mechanism.

Preferably, the hinge mechanism further comprises a securing device to secure the hinge mechanism in an extended position and the wheelchair in the operational position.

Typically, the securing device comprises a locking pin mounted on one of the first and second members, and a recess on the other of the first and second members, the locking pin engaging in the recess to secure the wheelchair in the operational position.

Typically, both of the first and second members comprise a plurality of holes, and the bolting arrangement may be inserted into one of the holes on one of the members and into one of the holes on the other member.

Typically, the holes on both members are equi-spaced along the length of the members. Preferably, the bolting arrangement is inserted into one of the holes on one of the members and one of the holes on the other member, both holes being equi-distanced from the coupling points for both members.

Typically, a seat is provided in which a user of the wheelchair sits. Preferably, the width of the seat is variable. More preferably, the seat comprises a back rest and a lower seat. Most preferably, the back rest and the seat are formed from a canvas material.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a wheelchair of the present invention, in an operational configuration; Fig. 2 is a rear view of the wheelchair of Fig. 1 in a semi-folded configuration; Fig. 3 is a rear view of the wheelchair of Fig. 1; Fig. 4 is a side view of the wheelchair of Fig. 1; Fig. 5 is a plan view of a hinge mechanism in a folded configuration, for use with the wheelchair of Fig. 1; Fig. 6 is a side sectional view of the hinge mechanism of Fig. 5, in a locked position; and Fig. 7 is a plan view of the hinge mechanism of Fig. 6 in a locked position.

Fig. 1 shows a wheelchair in accordance with the present invention and which comprises a right hand frame and a left hand frame. The right hand frame comprises a main frame tube 3a which is connected at its lower end to a lower frame tube 10a and at its upper end to a folding coupling 8a. The folding coupling 8a is connected at its upper end to a push handle 7a. The folding coupling 8a locks the push handle 7a in an upright position, and if it is unlocked allows the push handle to fold down towards the main frame tube 3a, which is particularly useful for transportation.

The lower frame tube 10a is connected at its rear to an axle mount plate 13a and at its front to a caster assembly 12a. The axle mount plate 13a is connected to the rear wheel 9a.

An arm rest assembly 5a is also connected to the right hand frame.

The left hand frame comprises corresponding components to the right hand frame, and these are designated by the reference b.

The right hand frame and the left hand frame are coupled together by a front hinge assembly 20 and a rear hinge assembly 21, and these will be described in detail subsequently.

The right hand and left hand main frame tubes 3a, 3b are coupled at their lower ends to respective footrest assemblies 2a, 2b and these will be described in detail subsequently.

The plane that the rear hinge assembly 21 operates on is at an angle approximately 450 to the forward direction of movement of the wheelchair, and is designated in Fig. 1 as the angle 1ZI. The plane that the front hinge assembly 20 operates on is at an angle approximately 450 to the reverse direction of movement of the wheelchair. The front 20 and rear 21 hinge assemblies operate at their respective angles to ensure the maximum rigidity and stiffness of the wheelchair.

The weight of the user will tend to make a wheelchair flex along the horizontal axis. When a wheelchair is in motion, hitting bumps and the like will tend to make it fold along a vertical axis. Locating the hinges at 450 add stiffness and rigidity to the wheelchair of the present invention to help prevent these bending moments occurring.

Fig. 2 shows the wheelchair in a semi-folded configuration, with the front hinge assembly 20a, 20b folding down and back and the rear hinge assembly 21a, 21b folding up and back.

This provides the wheelchair of the present invention with the advantage that when it is folded the wheelchair is less bulky. Also, the wheelchair is easier to fold from the rear, as the rear hinge is pulled toward the person folding the chair. Further, the hinges require only two fixing points and this means that they can be used with a single tube frame wheelchair.

Fig. 2 also shows that a width adjustable backrest canvas 6 is provided. The width of the backrest canvas 6 can be adjusted by increasing or decreasing the gap between the two ends of the canvas 6 by adjusting buckles 26. The seat canvas 4, which the user of the wheelchair sits on is shown in Fig. 1, and is also width adjustable.

Fig. 3 shows the wheelchair in an operational configuration, where the front hinge assembly 20 and the rear hinge assembly 21 are both locked.

The angles of the planes that the front 20 and rear 21 hinge assemblies operate on can be more clearly seen in Fig. 4, which shows the wheelchair in a side view, where the angles are denoted by the symbol e.

Fig. 5 shows a hinge assembly 20, 21 in a semi-folded position, which could be either the front hinge assembly 20 or the rear hinge assembly 21. The hinge assembly 20, 21 comprises a right hand member 20a, 21a and a left hand member 20b, 21b. The two members 20a, 21a, 20b, 2lb are pivotably coupled to their respective frames 10a, lOb at their respective couplings lia, 11b by their respective pivoting axles 22a, 22b. The two members 20a, 21a, 20b, 2lb are pivotably coupled to each other at central pivot pin 23. When the wheelchair is required to be used, the front 20 and rear 21 hinge assemblies are operated (in Fig. 5 the coupling 23 moving in a downward direction) so that the two lower frame tubes 10a, lOb are separated. When the hinge is fully extended, it lies in a flat position as shown in Figs. 6 and 7.

Mounted on the right hand member 20b, 21b is a knob 24 which is coupled to a spring loaded key 27. When the hinge is fully extended, the key 27 locates in slots 29 which are formed into the right hand member 20a, 21a and hence locks the hinge mechanism. In order to give the hinge mechanism further rigidity, left hand member 20a, 21a comprises a shoulder 25 which butts against the right hand member 20b, 21b when the hinge is fully extended.

A number of slots 28 are provided in the two members 20a, 21a, 20b, 21b, such that the central pivot pin 23 may be located at a number of different locations along the two members 20a, 21a, 20b, 21b. This provides the invention with the advantage that the hinge mechanism width is adjustable which allows the width of the wheelchair to be increased to accommodate the growth of its user.

A number of key slots 20 are also provided in the right hand member 20a, 21a so that the key can be inserted into the key slots 29 to lock the hinge mechanism for each different width.

Modifications and improvements may be made to the embodiments without departing from the scope of the invention.

Claims

CLAINS

1. A wheelchair comprising a frame which is moveable between a collapsed position and an operating position, the frame comprising a first side frame and a second side frame, the two side frames being connected by a hinge mechanism, the hinge mechanism being coupled to the first side frame at a first coupling point and being coupled to the second side frame at a second coupling point, the length of the hinge mechanism being adjustable such that when the wheelchair is in the operating position, the distance between the first coupling point and the second coupling point is adjustable to adjust the separation of the first and second side frames.

2. A wheelchair according to claim 1, wherein the hinge mechanism comprises a first and a second member, one end of the first member being coupled to the first side frame and one end of the second member being coupled to the second side frame.

3. A wheelchair according to claim 2, wherein the first and second members are pivotably coupled to each other.

4. A wheelchair according to claim 3, wherein the width of the wheelchair in the operating position is variable by varying the distance between the first or second coupling point and the pivotable coupling for at least one of the members.

5. A wheelchair according to either of claims 3 or 4, wherein the members are pivotably coupled by a bolting arrangement.

6. A wheelchair according to any of the preceding claims, wherein the two side frames are connected by two hinge mechanisms.

7. A wheelchair according to claim 6, wherein the two hinge mechanisms are longitudinally spaced apart in the direction of movement of the wheelchair.

8. A wheelchair according to claim 7, wherein there is a front hinge mechanism and a rear hinge mechanism.

9. A wheelchair according to either of claims 7 or 8, wherein the angle of the plane that one of the hinge mechanisms operates on is at an angle approximately 450 to the forward direction of movement of the wheelchair.

10. A wheelchair according to any of claims 7 to 9, wherein the angle of the plane that the other of the hinge mechanisms operates on is at an angle approximately 450 to the reverse direction of movement of the wheelchair.

11. A wheelchair according to claim 10, wherein the one hinge mechanism is the rear hinge mechanism, and the other hinge mechanism is the front hinge mechanism.

12. A wheelchair according to any of the preceding claims, wherein the hinge mechanism further comprises a securing device to secure the hinge mechanism in an extended position and the wheelchair in the operational position.

13. A wheelchair according to claim 12, wherein the securing device comprises a locking pin mounted on one of the first and second members, and a recess on the other of the first and second members, the locking pin engaging in the recess to secure the wheelchair in the operational position.

14. A wheelchair according to any of claims 5 to 13, wherein both of the first and second members comprise a plurality of holes, and the bolting arrangement is insertable into one of the holes on one of the members and into one of the holes on the other member.

15. A wheelchair according to claim 14, wherein the holes on both members are equi-spaced along the length of the members.

16. A wheelchair according to either of claims 14 or 15, wherein the bolting arrangement is inserted into one of the holes on one of the members and one of the holes on the other member, both holes being equidistanced from the coupling points for both members.

17. A wheelchair according to any of the preceding claims, wherein a seat is provided in which a user of the wheelchair sits, where the width of the seat is variable.

18. A wheelchair substantially as hereinbefore described with reference to the accompanying drawings.