WO1989006951A1

WO1989006951A1 - Wheeled invalid chairs

Info

Publication number: WO1989006951A1
Application number: PCT/GB1989/000094
Authority: WO
Inventors: Norman Dykes
Original assignee: Norman Dykes
Priority date: 1988-02-02
Filing date: 1989-02-02
Publication date: 1989-08-10
Also published as: AU3062189A; GB8802301D0

Abstract

The invention provides a chair frame for a wheeled invalid chair comprising a main frame (2) including a back support portion (6), seat portion (8) and leg portion (12) together with two side frame portions (14) arranged in a triangular configuration and provided at two lower angle regions (16, 20) thereof with mounting points for wheels (18) of said chair and, at the uppermost, third, angle region or apex (24), with mounting means (C at 24) for the seat portion (8) of the frame, the two triangular side frame portions (14) being secured together by two cross members (26, 28), a first cross member (28) linking the rear angle region (16) of one frame portion (14) to the rear angle region of the second frame portion (14) and a second cross member (26) linking said third angle regions (24) of the side frame portions (14). Advantageously, the joining members (C) are in pairs, members of each pair being non-handed and thus interchangeable.

Description

WHEELED INVALID CHAIRS The invention is concerned with improvements in or relating to frames for wheeled invalid chairs, particularly but not exclusively, lightweight chairs of the kind known as so-called sports chairs. Wheelchairs are conventionally available in a variety of forms. The most common of these forms are the institutional transfer chairs and self-propelled chairs, the folding wheelchair and the lightweight sports wheelchair. The latter, while generally considered to be the most useful for the permanent wheelchair user, is usually extremely expensive and therefore not readily available.

The invention therefore sets out to make it possible to construct a chair having a strong chassis with a number of features that make the unit adaptable for a wide range of sizes. The form of construction also allows for a range of disabilities to be accommodated with ease. The construction also allows for stability adjustments of the wheelchair as necessary, for example in the case of bilateral amputees, where the centre of gravity is much further toward the rear than is the case with paraplegics.

The invention therefore provides a chair frame for a wheeled invalid chair comprising a main frame including a back support portion, seat portion and leg portion together with two side frame portions arranged in a triangular configuration and provided at two lower angle regions thereof with mounting points for wheels of said chair and at the uppermost, third, angle region or apex with mounting means for the seat portion of the frame, the two triangular side frame portions being secured together by two cross members, a first cross member linking the rear angle region of one frame portion to the rear angle region of the second frame portion and a second cross member linking said third angle regions of the side frame portions.

Advantageously, the mounting means slidably mount the seat portion for adjustment between forward and rearward positions with respect to the side frame portions, to ensure maximum stability irrespective of the centre of gravity of the user.

Advantageously, the frame portions may be formed by assembling tubular strut members into the desired configuration and securing them by means of joining members having strut receiving sockets. Preferably corresponding joining members on opposite sides of the chair are identical, i.e. non-handed, to facilitate assembly.

Conveniently, assembly is further facilitated by the use of metal-to-metal bonding agents or other adhesive compounds, which also avoids stresses in the structure.

There will now be described an example of a chair according to the invention. It will be understood that the description which is to be read with reference to the drawings is given by way of example only and not by way of limitation. In the drawings:

Figure 1 is an isometric view of a chair, with wheels omitted for clarity?

Figure 2 is a side view of the chair shown in Figure 1 ; and

Figure 3 is a side view of the chair in a partially folded condition.

In Figure 1, the chair is constructed in tubular aluminium, comprising a main frame 2 comprising a back support 4 with a flexible back web or rest 6 (shown in chain dotted lines), a seat portion 8 with a flexible seat web 10 also shown in chain-dotted lines) and a leg portion 12.

The main frame 2 is supported on two side frame portions 14 each having a triangular configuration. At the rearmost angle region 16 of each triangular frame is provided adjustable mounting for a large rear wheel 18 of the chair. At the front angle region 20 of each frame is a bracket 21 mounting a small front wheel 22. At the third angle region thereof, at apex 24, each side frame 14 is lounted adjustably in fore and aft directions on the seat portion 8 and the frames are linked together adjacent the top apices 24 and the front angle regions 20 by cross members 26, 28 respectively.

The facility to adjust the position of the main frame with respect to the side frames by positioning the struts of the seat portion 8 in the casting C at the apex 24 of the side frames, takes account of the different positions of centres of gravity between, say, a paraplegic and a person who has both legs amputated.

Arm members 30 are provided on the back support 4 and mounted for pivotal movement (as shown at arrow A in Figure 3) about a transverse pivot line 29, into a position parallel with the back support 4, prior to being pivotted downwardly, together with the back support, into a folded- down condition for stowage.

As mentioned above, the frame portions comprise tubular aluminium in the form of struts received at free ends thereof in sockets 15 in castings C at, for example, regions 16, 20 and 24 of the side frames and at other joints, hinged or rigid, throughout the construction. The castings C are designed to be non-handed so that, for example, the left hand casting at 20 is identical to the right hand casting to simplify assembly. The struts of the frame assembly are secured in the castings C in the present example by suitable bonding agents such as toughened structural epoxy adhesives. If desired, however, the seat portion struts 8 may be releasably clamped by clamping means provided at 31 in castings C, at the third angle region, 24, should some facility for later adjustment be required. It will be understood that the length of the struts may be selected as necessary for the size of chair required to suit the patient.

Mounted on the side frame 14 of the chair for co-operation with the tyre tread surface of the wheel 18 is a brake device indicated at 32 in Figures 2 and 3. Various modifications may be made within the scope of the present invention as defined in the following claims.

Claims

CLAIMS :

1. A chair frame for a wheeled invalid chair comprising a main frame (2) including a back support portion (6), seat portion (8) and leg portion (12) together with two side frame portions (14) arranged in a triangular configuration and provided at two lower angle regions (16,20) thereof with mounting points for wheels (18) of said chair and, at the uppermost, third, angle region or apex (24), with mounting means (C at 24) for the seat portion (8) of the frame, the two triangular side frame portions (14) being secured together by two cross members (26,28), a first cross member (28) linking the rear angle region (16) of one frame portion (14) to the rear angle region of the second frame portion (14) and a second cross member (26) linking said third angle regions (24) of the side frame portions (14).

2. A frame as claimed in claim 1, wherein the mounting means slidably mount the seat portion (8) for adjustment between forward and rearward positions with respect to the side frame portions (14).

3. A frame as claimed in either one of claims 1 and 2, wherein the side frame portions (14) comprise tubular strut members assembled into a triangular configuration, joining members (C) provided with sockets (15) being adapted to receive end portions of said strut members (8,12,14) in said sockets (15) .

4. A frame as claimed in claim 3 wherein said joining members (C) are in pairs, joining members of each pair being identical, i.e., non-handed.

5. A frame as claimed in either one of claims 3 and 4 wherein joining member end portions are secured in said sockets (15) by means of suitable bonding cements or other adhesives.

6. A frame as claimed in either one of claims 3 and 4, wherein selected ones of the strut members (8) are received in clamping means (31) in the assembly of the frame.

7. A frame as claimed in claim 6, wherein said clamping means (31) forms part of said joining members (C at 24).

8. A frame as claimed in any one of the preceding claims, wherein said back support portion (4) is capable of pivotal movement about a transverse axis (29) into a folded-down position for stowage.