EP0162835B1

EP0162835B1 - Foldable wheeled chair

Info

Publication number: EP0162835B1
Application number: EP83900274A
Authority: EP
Inventors: Derek F. Wrigley
Original assignee: LEMERCIER Daniel
Current assignee: LINIDO TE PIJNACKER BV
Priority date: 1983-01-14
Filing date: 1983-01-14
Publication date: 1989-09-20
Also published as: AU1102783A; ATE46432T1; DE3380587D1; EP0162835A1; DK437284D0; NO843628L; DK437284A; WO1984002647A1; JPS60500359A

Abstract

A foldable wheeled chair comprising a chair (2) mounted on a wheeled frame (1) is provided with a plurality of joint means (9, 10, 11, 23) enabling different parts (3, 4, 5, 24) of the chair (2) to give an infinity of positions one relative to another and the chair (2) to give an infinity of positions relative to the frame (1). Both frame (1) and chair (2) comprise modular adjustable elements so as to permit the construction of a large number of models each being well adapted to meet the particular size and infirmity of the occupant.

Description

The invention relates to a foldable wheeled chair, principally for infirm patients, comprising a chair which is mounted on a wheeled frame, said chair comprising at least a seat, a back-seat and foot-supports, a plurality of joints being provided to allow the several parts of the chair to take an infinity of mutual relative positions and an infinity of positions relative to the frame, control means located to enable the occupant of the chair to adjust said positions, said wheeled frame comprising beams connecting the wheels to the frame and two telescopic elements to adjust the seat vertically with respect to the frame.
Such a foldable wheeled chair is known from DE-A-2517418. This known wheeled chair comprises at both sides a horizontal beam for supporting the wheels and castors, said beams being provided with two expandable upright elements for adjusting the elevation and inclination of the seat. The known wheeled chair therefore is relatively heavy. A more important drawback of the known wheeled chair, however, is that it is a so-called one-dimension and one-type wheeled chair, which means that shop-owners have to keep a stock of wheeled chairs of different dimensions and types, which is very inefficient of course.
The invention aims at improving the above. According to the invention this has been reached in that said beams have adjustable members telescopically slidable thereon, the wheels being mounted on the adjustable members, each adjustable member having several holes at different heights to receive the axles of wheels of different sizes, which telescopic elements are composed of a first part which is' fixed to said beam and a second part, slidable relative to the first part and which supports the chair, and in that said first part of said telescopic elements is vertically adjustably fixed to said beam.
The invention will be better understood and still further objects and advantages will become apparent from the following description of the preferred embodiment in the accompanying drawings in which:

Figure 1 is a side elevation of a foldable wheeled chair,
Figure 2 is a front elevation of the same,
Figure 3 is a schematic side elevation to illustrate possible positions of the wheeled chair,
Figure 4 is a schematic view of the adjustability of the handlebar, and of the possible extensions of the chair and wheeled frame.
Figure 5 to 8 are schematic side elevations illustrating different kinds of wheels or castors that may be used,
Figure 9 is a side elevation of a joint,
Figure 10 is a plan of the same joint of figure 9,
Figure 11 is a schematic side elevation to explain the necessity of a compensating device,
and Figure 12 is a cross section of the foot-support comprising an automatic compensating device.

As illustrated on the drawings, the foldable wheeled chair comprises a wheeled frame 1 and a chair 2. The chair comprises at least a seat 3, a back-rest 4 and foot-supports 5. As is the case for conventional chairs, additional components may be added such as arm-rests 6, head-rests (not shown), leg-rests 7 and a handle-bar 8.
The chair 2 comprises a plurality of joints 9-12: joint 9 between back-rest 4 and seat 3, joint 10 between seat 3 and leg-rest 7, joint 11 between leg-rest 7 and foot-support 5, and joint 12 between back-rest 4 and handle-bar 8. The joints allow the chair to show an infinity of positions, as each part of the chair can pivot relative to the other part with which it is articulated.
On each side of the frame 1 are located unitary elements 13 on which wheels 14 or castors 15 of different sizes and types may be mounted. For instance, as shown on figure 5, the front wheel 15 is a castor with a diameter of about 200 mm and the backwheel 14 has a diameter of about 600 mm and is provided with a well-known hand-rim 16.
On figure 6, front wheels 15 are castors of about 200 mm and back wheels 14 are about 300 mm diameter.
On figure 7, front wheels 15 have a diameter of about 600 mm and back wheels 14 are 200 mm diameter castors. Figure 8 shows the case where both front 15 and back wheels 14 are about 300 mm diameter.
It is evident that many other types of wheels may be mounted on the frame and that the preferred embodiments shown and described have been given as examples and do not constitute a limiting list.
Referring back to figure 2, the unitary element 13 is adapted to support two replaceable members 17 and 18. These members are adapted to slide into the element 13 so as to allow different length of the frame 1. Each member comprises several holes 19, located at a plurality of positions to receive the axles of the different wheels.
Located almost on the vertical of the gravity center of an occupant a telescopic element 20 comprises a part 21, fixed to unitary element 13, and relative to which can slide a second part 22 in a vertically adjustable way. Inside this second part 22 is located a slide which allows the chair to be folded as it is well-known in the art.
The height of the seat may be adjusted by raising or lowering part 22 relative to part 21. Locking means such as bolts or other well-known means maintain part 22 in the required position. Part 22 is adapted to support the chair 2 through a joint 23.
As shown in figure 3 the joints 9, 10 and 23 allow the chair to give an infinity of positions between a sitting position B-B and a lying or sleeping position F-F. Joint 23 give the seat 3 an infinity of position between two almost vertical positions G-G and G'-G'. Almost vertical positions means positions as near as possible to vertical positions. In fact these positions depend upon the height where joint 23 is raised. The higher it is raised, the more vertical will be these positions. The limitation is not caused by joint 23 but by the foot-support touching the ground.
Some particular positions are shown on figure 3:

Position A-A is a transferring or stepping in or out position, which retains the chair position B-B gently tilted forward to help front transfer,
Position B-B is an active sitting-up position.
Position C-C is a semi-active position,
Position D-D is a relaxing position,
Position E.E. is a resting position.

Joint 9 enables back rest 4 to assume an infinity of positions relative to seat 3 at angles between about 80° and 180°, that is to say between a position a little more closed than sitting position and lying position. When the angle becomes less than 80° the joint 9 allows the back-rest 4 to be quickly folded on to seat 3 so as to reduce the volume of the chair.
On the rear side of the back-rest 4 is located a handle-bar 8 which may be adjusted in a pivoting way so as to give a plurality of heights as shown by H, I and J on figure 4.
One of the most important advantages of the unitary elements 13 and 24 is that they can comprise a central part relative to which the joints 9, 10 and 11 may be extended or contracted. Each part of the chair may thus be adjusted to the particular sizes of the occupant making the chair, in effect, made to measure as shown by positions K, L, M, N, O, P on figure 4.
Referring now to figures 11 and 12 it must be realized that the knee joints 25 of the occupant and the joints 10 between seat 3 and leg-rests 7 not coincide. Knee joints 25 are higher than joints 10 and the mutual distance depends upon the thickness of the seat 3 and whether or not the occupant uses a cushion. So when the leg is in a horizontal position, the leg rest needs to be longer than when the leg is in a vertical position.
To compensate for this difference of length the leg tube 24 is provided with an outer tube 26 in which can slide an inner tube 27. This inner tube 27 has a head part 29 which fits in the outer tube 26 and a narrower part 30 around which is located a compression spring 31. Spring 31 abuts on one end against the head part 29 of the inner tube 27 and on the other end against the closed end 32 of outer tube 26. A locking device such as a screw 33 permits the fixing of inner tube 27 relative to outer tube 26 in the required position.
So when screw 33 released, spring 31 pushes 35 head part 29 toward joint 10: leg tube 24 is thus in its shortest position, appropriate to the lower leg of the occupant when seated in the normal seating position. When raising toward a horizontal position the occupants legs push the foot-rests thus compressing spring 31. When in required position, the occupant screws in knob 33, thus fixing the foot-rests in the most suitable position.
Joints can be activated by transmission means so as to obtain infinities of positions. Figures 9 and 10 show the joint 10 between the seat 3 and the leg tube 24 which comprises a driven means 34 fixed to the pivoting part that is the leg tube 24. The driven means 34 cooperates with a driving means 35 fixed to the part relative to which pivots the pivoting part, in this case seat rail 3. Driven means 34 and driving means 35, each comprising a toothed wheel 36, 37 connected together by a camshaft 38 so as to form a well-known planetary transmission. Transmission means generally are activated by a control means, in this case, a knob 39 fixed to the cam-shaft 38. One of the advantages of such a transmission means is that a locking mechanism is not necessary to make the pivoting part keeps its position when the driving means is released. It is evident that the described transmission means 36-38 are only given as an example and that many other types of transmission such as wormgears may be used within the scope of invention.
All transmission means are activated by control means which may be remote control means so that they can be located in the most suitable location to enable the occupant himself to obtain the most desirable position. The control means may be located on either side of the chair. But, due to the fact that the chair is built up from modular elements without any transverse rigidity transmission of desired movement to the other side of the chair must be achieved by a foldable or a flexible transmission. Such transmission may comprise cable, universal joint, belt,.... or other well-known flexible or foldable transmission device.
The description set forth illustrates the preferred embodiment of the foldable wheel chair of the invention. It is to be understood, however, that many variations to the drawings and description may be adopted within the scope of the invention as defined by the claims.

Claims

Foldable wheeled chair, principally for infirm patients, comprising a chair (2) which is mounted on a wheeled frame (1), said chair (2) comprising at least a seat (3), a back-seat (2) and foot-supports (5), a plurality of joints (9, 10, 11, 23) being provided to allow the several parts of the chair to take an infinity of mutual relative positions and an infinity of positions relative to the frame, control means (39) located to enable the occupant of the chair to adjust said positions, said wheeled frame (1) comprising beams (13) connecting the wheels (14, 15) to the frame (1), and two telescopic elements to adjust the seat vertically with respect to the frame,
characterized in that said beams have adjustable members (17, 18) telescopically slidable thereon, the wheels (14, 15) being mounted on the adjustable members, each adjustable member (17) having several holes (19) at different heights to receive the axles of wheels of different sizes, which telescopic elements (20) are composed of a first part (21) which is fixed to said beam (13) and a second part (22), slidable relative to the first part (21) and which supports the chair (2), and in that said first part of said telescopic elements is vertically adjustably fixed to said beam.