WO2004112674A2

WO2004112674A2 - Improvements in or relating to disability vehicles and fastening devices

Info

Publication number: WO2004112674A2
Application number: PCT/GB2004/002672
Authority: WO
Inventors: Huw Edgward Thomas; Robert Joseph Walsh
Original assignee: Invacare Limited
Priority date: 2003-06-20
Filing date: 2004-06-21
Publication date: 2004-12-29
Also published as: WO2004112674A3

Abstract

A wheelchair includes side frames (2) and (4) which are moved towards each other in displacing the vehicle from an unfolded condition to a folded condition, side bars (28) extending substantially horizontally above the respective side frames (2) and (4), a flexible seat (26) connected at respective lateral edges thereof to the side bars (28), interconnected cross members (38) connected at upper ends thereof to the respective side bars (28), and connected at lower ends thereof to the respective side frames (2) and (4), and readily releasable fastening devices (44) which serve, in fastening conditions thereof, to act between the side frames (2) and (4) and the side bars (28) to prevent the side frames (2) and (4) from being moved towards each other when the vehicle is in its unfolded condition.

Description

IMPROVEMENTS IN OR RELATING TO DISABILITY VEHICLES AND

FASTENING DEVICES

According to one aspect of the present invention, there is provided a disability vehicle including first and second side frames which are moved towards each other in displacing said vehicle from an unfolded condition to a folded condition, first and second side bars extending substantially horizontally above the respective first and second side frames, a ^' flexible seat connected at respective lateral edges thereof to the side bars, first and second connections which are connected to each other and which are connected at respective upper ends thereof to said first and second side ^'bars, respectively, and connected at respective lower ends thereof to the second and first side frames, respectively, and a readily releasable fastening device which serves, in a fastening condition thereof, to act between the first side frame and the first side bar to prevent said side frames from being moved towards each other when said vehicle is in its unfolded condition. Owing to this aspect of the invention, it is possible to improve the rigidity of the vehicle when moving, especially over uneven ground.

Although it is possible to employ only one such fastening device, preferably two or more, such fastening devices are employed, at least one being associated with each side frame.

The flexible seat may comprise a sheet of ^' flexible material, or a pair of substantially rigid seat halves hinged together longitudinally of the vehicle. According to another aspect of the present invention, there is provided a readily releasable fastening device comprising an abutment, a mounting, a link pivotally mounted in said mounting and swingable to a fastening position in which said link extends to beyond said abutment, and an element turnably supported by said link and including an eccentric tightenable against said abutment to put said link in tension, said element being turnable, with said link being in said fastening position, to displace said eccentric into and out of contact with said abutment. In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, in which: -

Figure 1 is a side perspective view of a foldable, powered wheelchair; Figure 2 is a fragmentary perspective view of part of the wheelchair seen from below a seat piece of the wheelchair;

Figure 3 is a fragmentary perspective view from above of a portion of the wheelchair including a fastening device and with the seat piece removed for ease of ^' illustration;

Figure 4 is a sectional side elevation of the fastening device; and

Figure 5 is a fragmentary perspective view showing a modified version of the fastening device. Referring to the drawings, the wheelchair includes left- hand and right-hand side frames 2 and 4 which are substantially identical to each other. Rear wheels 6 are rotatably mounted on the side frames, as are respective front castor wheels 8. The rear wheels 6 are driven by respective motors 10 mounted on the side frames and supplied by batteries contained in carriers 12 slung between the side frames. Left-hand and right-hand arm rests 14 and 16 are mounted on respective side frames 2 and 4, whilst a control device 18 for the motor 10 is mounted on the side frame 4. Pivotally suspended from the fronts -of the side frames are respective foot rests 20. Towards the rear of the side frames are respective push handles 22 between which is provided a back-rest piece 24 of flexible material. A seat piece 26 of such flexible material is slung between two substantially horizontal, seat side bars 28. The bars^' 28 rest in end and intermediate, upwardly open brackets 30 and 32 fixed to and projecting upwardly from substantially horizontal, elongate members 34 of the side frames 2 and 4. Below the seat piece 26 is a foldable, X-arrangement 36 comprised of two cross members 38 which, at respective upper ends thereof, are fixed to the respective side bars 28 at respective locations intermediate the ends of those side bars. Centrally of the X- arrangement 36, the cross members are pivotally interconnected by a substantially horizontal pivot 40. At their respective lower ends, the cross members 38 are pivotally connected to the respective side frames 2 and 4 by substantially horizontal pivots 42.

The wheelchair can be folded from the use (i.e. unfolded) condition shown thereof in the drawings to a transportation (i.e. folded) condition by unslinging the battery-containing carriers 12 and then lifting the side bars 28 away from the elongate members 34 (such as by grasping the piece 26 centrally at its front and rear and pulling upwards thereon) , so that the side bars 28 are lifted out of the brackets 30 and 32 and are swung towards each other, whereby, via the X-arrangement 36, the side frames 2 and 4 are displaced towards each other and thereby cause the flexible piece 24 to fold.

The wheelchair as so far described with reference to the drawings is known per se. A disadvantage of this per se known wheelchair is that, while the wheelchair is occupied and moving, especially over uneven ground, the side bars 28 may tend to lift out of the brackets 30 and 32, so causing uneasiness for the occupant. In order to render the foldable wheelchair more rigid while it is moving, respective readily releasable, fastening devices 44 are provided at respective opposite sides of the wheelchair, laterally inwardly of the side frames 2 and 4 and the side bars 28, for clamping the side bars 28 in the brackets 30 and 32. Each device 44 includes a metal sleeve 46 closed at its lower end, so as to form a bucket. The sleeve wall is formed with diametrically opposite through holes 48 and 50 serving as bearings for a substantially horizontal shaft 52 formed with a 60° eccentric cam 54 within the sleeve 46. Externally of the sleeve 46, the shaft 52 has fixed thereto a radial lever arm 56 whereby quick release of the fastening device 44 can be obtained. Closely encircling the cam 54 is a collar 58 to which is fixed a radial link rod 60 extending upwardly from the collar 58 and externally threaded at 62 at its upper end where it is screwed into a bore through a substantially horizontal pivot bolt 64 mounted in a O-mounting 66 fixed to the adjacent side bar 28. Fixed to the elongate member 34 at a location directly below the U-mounting 66 is a horizontally inward, U-shaped abutment 68 able to receive the rod 60. In the clamping condition of the device 44 shown in Figure 3, the abutment 68 receives the rod 60 and the arm 56 is in a substantially vertically upwardly extending over-centre condition in which it rests against the member 34, and the cam 54 urges the collar 58 and the rod 60 downwards while urging the sleeve 46 upwards to bear against the underside of the abutment 68. Thereby, the side bar 28 is clamped firmly into the brackets 30 and 32. Of course, in this condition the wheelchair is not foldable. In order to allow the wheelchair to be folded, the arm 56 is swung through dead centre in an arc of roughly two right-angles into the released condition shown in Figure 4 in which the rod 60 can be swung from out of the abutment 68 so that the side bar 28 can move upward with the sleeve 46 which comes to bear against the free ends of the limbs of the abutment 68 to prevent the rod 60 from re-entering the abutment. Then the seat piece 26 can be grasped and pulled upwards for folding of the wheelchair. Following unfolding of the wheelchair and to re-fold the same, the rod 60 is caused to re-enter the abutment 68 and the arm 56 turned from its Figure 4 condition into its Figure 3 condition to cause the sleeve 46 to move linearly upwards to come to bear against the underside of the abutment 68 to press the side bars 28 into the brackets 30 and 32. Referring to Figure 5, the modified fastening device 44 is simpler and. less expensive to produce than that of Figures 3 and 4. The items 46 to 56 are replaced by simply a lever 70 consisting of a section of an aluminium extrusion and by a horizontal pivot 72 extending through an eccentric tubular portion 74 of the lever 70. The item 68 is replaced by a T- shaped member 76 also consisting of a section of an aluminium extrusion, but with portions cut away to form the main limb 78 of the T. The underneath surface 80 of the main limb 78 is convex (its convex form being caused by the corresponding longitudinal surface of the aluminium extrusion having been convex) to promote the over-centre toggle effect of the eccentric portion 74 which co-operates with that surface 80. The outer lateral surface 82 of the cross limb of the member 76 is of concave form to lie snugly against the external peripheral surface of the member 34 to which the cross limb is fixed. The pivot 72 is mounted in and between a pair of links 84 pivotally mounted at their upper ends to a U-shaped bracket 86 fixed to the bar 28. In the clamping condition shown in Figure 5, the portion 74 is in an over-centre condition relative to the convex surface 80. To release the fastening device, the lever 70 is turned to force the portion 74 thereof through dead centre relative to the surface 80 and is pulled to swing the links 84 away from the member 34.

Claims

1. A disability vehicle including first and second -side frames which are moved towards each other in displacing said vehicle from an unfolded condition to a folded condition, first and second side bars extending substantially horizontally above the respective first and second side frames, a flexible seat connected at respective lateral edges thereof to the side bars, first and second connections which are connected to each other and which are connected at respective upper ends thereof to said first and second side bars, respectively, and connected at respective lower ends thereof to the second and first side frames, respectively, and a readily releasable fastening device which serves, in a fastening condition thereof, to act between the first side frame and the first side bar to prevent said side frames from being moved towards each other when said vehicle is in its unfolded condition.

2. A vehicle according to claim 1, wherein said first and second connections comprise first and second cross members pivotally connected at said respective lower ends to the second and first side frames, respectively.

3. A vehicle according to claim 1 or 2 and further comprising a second readily releasable fastening device which serves, in a fastening condition thereof, to act between the second side frame and the second side bar, thereby to prevent said side frames from being moved towards each other when said vehicle is in its unfolded condition.

4. A vehicle according to any preceding claim and further comprising upwardly open brackets which are attached to the side frames and in which the side bars rest when said vehicle is in its unfolded condition, the or each fastening device serving, in its fastening condition, to press its associated side bar firmly into the brackets in which that side bar rests .

5. A vehicle according to any preceding claim, wherein the or each fastening device is disposed laterally inwards of its associated side bar and its associated side frame.

6. • A vehicle according to any preceding claim, wherein the or each fastening device comprises an abutment provided on

5. one of the corresponding side bar and the corresponding side frame, a mounting provided on the other of the corresponding side bar and the corresponding side frame, a link pivotally mounted on said mounting and swingable to a fastening position in which said link extends to beyond said abutment, 0 and an element supported by said link and tightenable against said abutment to put said link in tension.

7. A vehicle according to claim 6, wherein the or each said element includes an eccentric and is turnable, with said link being in said fastening position, to displace said eccentric 5 into and out of contact with said abutment.

8. A vehicle according to claim 6 or 7, wherein said element comprises a section of an extrusion.

9. A vehicle according to claim 6, 7, or 8, wherein the or each said abutment is the stem limb of a T-shaped member of 0 which the cross limb is attached to said one of the corresponding side bar and the corresponding side frame.

10. A vehicle according to claim 9, wherein the or each said T-shaped member has been formed by a method including extrusion.

11. A vehicle according to claim 9 or 10, wherein that longitudinal surface of the or each said cross limb further from said stem limb is transversely concave.

12. A vehicle according to any one of claims 6 to 11, wherein that surface of the or each abutment which contacts said element is transversely convex to promote an over-centre toggle effect.

13. A readily releasable fastening device comprising an abutment,- a mounting, a link pivotally mounted in said mounting and swingable to a fastening position in which said link extends to beyond said abutment, and an element turnably supported by said link and including an eccentric tightenable against said abutment to put said link in tension, said element being turnable, with said link being in said fastening position, to displace said eccentric into and out of contact with said abutment.

14. A fastening device according to claim 13, wherein said element comprises a section of an extrusion.

15. A device according to claim 13 or 14, wherein said abutment is the stem limb of a T-shaped member.

16. A device according to claim 15, wherein the T-shaped member has been formed by a method including extrusion.

17. A device according to claim 15 or 16, wherein that longitudinal surface of the cross limb of the T-shaped member further from said stem limb is transversely concave.

18. A device according to any one of claims 13 to 17, wherein that surface of the abutment which contacts said element is transversely convex to promote an over-centre toggle effect.