GB2041735A - Reclining chair - Google Patents

Abstract

An office chair (Figures 1 to 3) which as a back 23 pivoted to frame members (arms 15, 16). The back is hinged to a seat 20. The seat 20 has a slot (45) in its underside which engages a key (37) on the frame to allow the seat limited sliding movement in a fore and aft direction. By leaning back in the seat the back inclines to increase its angle to the seat at the same time causing the seat to slide forwardly. <IMAGE>

Description

SPECIFICATION Reflex chair This invention relates to a chair which has an adjustable seat and back.

Such chairs are known and various methods of adjustment of the angle of the back and of the horizontal position of the seat have been proposed.

It is an object of the invention to provide a chair of simple but robust construction in which, by changing the inclination of the back of the chair the position of the seat is automatically changed.

A further object is to provide such a chair in which no ancilliary locking means or adjustment means are needed.

According to the invention, a chair comprises a frame member back member pivoted to the frame member along a horizontal axis at an intermediate part of the back, and a seat member hinged at or adjacent the lower end of the back member, the seat being slidable backwards and forwards within a predetermined range and being guided by one or more key and slot devices which permit the horizontal sliding movement but prevent any substantial sideways or vertical movement of the seat, the arrangement being such that, as the back is inclined so that the angle between the seat and the back increases, the seat automatically slides forward to any desired position within said range.

Preferably the key is carried on and is upstanding from a transverse portion of the frame member.

Alternatively the key may be carried on and be upstanding from a portion of the frame member which runs from the front to the back of the chair.

The key is preferably located at or adjacent the front part of the frame member.

The key may be approximately T-shaped in cross section.

Preferably the key is so shaped and dimensional that it can be forced into said slot, can move freely relatively to the slot, but resists withdrawal from the slot unless substantial force is applied For example, the key may be substantially V-shaped in cross section, the gap between the arms of the V allowing the arms to flex towards each other as the key is forced into the slot.

The key may be made of a hard plastics material.

Preferably the seat is moulded from a rigid or semi rigid plastics material, which may, for example, be solid polypropylene or foamed propylene or some other such material, for example ABS.

The front face of the back member is preferably concave in cross section and the pivot points are preferably at or adjacent the front edges of the concave face.

The frame member may comprise a single tube having a central transverse portion, upstanding portions at each end of the transverse portion and rearwardly extending arms at the upper ends of the upstanding portions, the back being pivoted from the rear ends of the arms and the key being mounted at or adjacent the middle of said central transverse portion. The single tube may be supported on a single extendable column in turn carried on a base for use as an office or typist's chair.

The base may be a 4-prong or 5-prong base with a wheel, castor or ground-contacting foot on each leg, or a trumpet base, for example.

Another alternative is to have a frame member with an upstanding support member at each of two rear corners, the back member being pivoted on said upstanding support members.

In the accompanyihg drawings: Figure 1 is an exploded view of an office, or typist's, chair embodying the invention; Figure 2 is a side elevation of the same chair, when assembled; Figure 3 is a scrap side elevation, partly in section, showing the key and slot device:: Figure 4 is a perspective view of a stacking frame for a chair embodying the invention, the back and seat being removed to show details more closely; Figures 5, 5a, 5b and Sc are sections through parts of the chair shown in Figure 4; Figure 6 is a scrap side elevation, partly in section, of the key and slot device employed in the chair shown in Figures 4 and 5; Figure 7 is a side elevation of the same chair; Figure 8 is a front elevation of a multi-seating bank of chairs embodying the invention; Figure 9 is an end elevation of the chairs shown in Figure 8; and Figure 10 is a side elevation of a chair embodying the invention with a writing arm.

The office chair shown in Figure 1 comprises a frame member in the form of a single tube 10 which has a central transverse portion 11, upstanding tube portions 12, 13, one at each end of portion 11, and rearwardly extending arms 15, 1 6 at the upper ends of the upstanding portions 1 2, 1 3 respectiveiy.

The tube 10 is carried by an extendable vertical column 1 7 on a base 18 with five legs 19 each terminating in a castor 1 9a (not shown in Figure 1) (qr a 4-prong base or a trumpet base).

The chair has a moulded propylene seat 20 hinged at 21 and 22 to a moulded back 23.

Two moulded plastic arm rests 24 (only one of which is shown in Figure 1) are attached to arms 1 5 and 1 6.

The back 22 is attached to the rear ends of arms 16 by pivot pins 23 passing through apertures 24 and 25. The back is thus pivoted on a horizontal axis at the mid portion of the back. A moulded nyion glide or key member 26 is attached to the transverse portion 11 of tube 10.

The key member 26 is T-shaped as shown and hays a base part 26a. Figure 3 iilustrates the way in which the base part 26a is fixed to transverse portion 11 by self-tapping screws 27. It also illustrates how the T portion 26 is engaged in a groove 28 in the underside of seat 20. The groove is shaped to allow the T portion to snap into it and to allow horizontal sliding movement of seat 20 but no substantial sideways or vertical movement.

The fully assembled chair is shown in Figure 2 and the two extreme positions of the back and seat are illustrated by firm and dotted lines. The limit of movement is determined by the length of groove 28. By leaning back and thus applying pressure to the upper part of the back 23 the back is caused to pivot and thus increase the angle between the seat and back. Because the back and seat are hinged together the seat will slide forwardly. As the back moves from the firm to the dotted line position so the seat also moves automatically from the firm to the dotted line position.

As can be seen from Figures 1 and 2 the back is concave and the pivot points of the back are at the forward edges of the concave seat portion.

Figures 4 to 7 show a stackable chair which has a frame 30 (figure 4) with upstanding support member 31, 32 at each of the two rear corners 33, 34 of the frame. Inwardly turned top portions 35, 36 of support members provide pivot points for the same kind of back 23 as is shown in Figure 1. In this chair the key member 37 is supported on a base part 38 on a support member 39 extending between back and front rails 40, 41. The shape of support member 39 is shown in section in Figure 5b and the shape of the key member 37 and base part 38 is shown in Figures 5a and 5c.

The key member is Y-shaped, the space 42 between the arms 43,44 of the Y creating a resilience which enables the key member, or glide member, to snap into the groove in the underside of seat 20 (Fig. 5) and to be retained there against removal by normal usage of the chair.

The assembly of hinged seat 20 and back 23 is identical to that shown in Figure 1 and the sliding action of the seat and pivoting of the back are exactly as previously described in relation to Figure 1. Figure 6 shows in detail how the key member 37 enters slot 45 in seat 20.

Figures 8 and 9 show an array of multi-seating chairs supported on pairs of legs 50 which carry a rigid frame member 51 in turn supporting upstanding member 52 terminating in arms 53 the ends 54 of which provide pivot supports 55 for back 23. The remaining details are as previously described in relation to Figure 1, the seat and back assembly and the key and groove arrangement being identical to that previously described. Each seat of the multi-seating arrangement can be adjusted independently.

Figure 10 illustrates a multi-seat assembly of the type shown in Figures 8 and 9 and shows the two extreme positions of adjustment of seat 20 and back 23. A writing arm or tabie 56 is shown attached to arm 53a. The table 56 can be pulled forward as shown to the dotted line position 56a and it can be swung into the vertical position 56b for access to the chair. The seat 23 and back 20 are adjustable as described previously.

Claims (22)

1. A chair comprising a frame member, a back member pivoted to the frame member along a horizontal axis at an intermediate part of the back, and a seat member hinged at or adjacent the lower end of the back member, the seat being slidable backwards and forwards within a predetermined range and being guided by one or more key and slot device wich permit the horizontal sliding movement but prevent any substantial sideways or vertical movement of the seat, the arrangement being such that as the back is inclined so that the angle between the seat and the back increases, the seat automatically slides forward to any desired position within said range.

2. A chair according to claim 1 and in which said horizontal axis along which the back member is pivoted is at or near the mid point of the back.

3. A chair according to claim 1 and claim 2 and in which the seat is guided by a single key and slot device, the slot being aligned with the fore and aft axis of the seat.

4. A chair according to any of claims 1 to 3 and in which the member slot is formed in the underside of the seat.

5. A chair according to any preceeding claim and in which the key is carried on and is upstanding from a transverse portion of the frame member.

6. A chair according to any preceeding claim and in which the key is carried on and is upstanding from a portion of the frame member which runs from the front to the back of the chair.

7. A chair according to claim 5 or claim 6 and in which the key is located at or adjacent the front part of the frame member.

8. A chair according to any preceding claim and in which the key is approximately T-shaped in cross section.

9. A chair according to any preceeding claim and in which the key is so shaped and dimensioned that it can be forced into said slot, can move freely relatively to the slot, but resists withdrawal from the slot unless substantial force is applied.

10. A chair according to claim 9 and in which the key is substantially V-shaped in cross section, the gap between the arms of the V allowing the arms to flex towards each other as the key is forced into the slot.

11. A chair according to claim 8 or claim 9 and in which the key is made of a hard plastics material.

1 2. A chair according to any preceeding claim and in which the seat is moulded from a rigid or semi rigid plastics material.

1 3. A chair according to claim 12 and in which the plastics material is solid polypropyiene or foamed polypropylene or ABS.

14. A chair according to any preceeding claim and in which the front face of the back member is concave in cross section and the pivot points are at or adjacent the front edges of the concave face.

15. A chair according to any preceeding claim and in which the frame member comprises a single tube having a central transverse portion, upstanding portions at each end of the transverse portion and rearwardly extending arms at the upper ends of the upstanding portions, the back being pivoted from the rear ends of the arms and the key being mounted at or adjacent the middle of said central transverse portion.

16. A chair according to claim 1 5 and in which the single tube is supported on a single extendable column in turn carried on a base to form an office or typist's chair.

1 7. A chair according to claim 1 6 and in which said base is a 4- or 5-prong base with a wheel, castor, or other ground-contacting foot on each leg, or a trumpet base.

18. A chair according to any of claims 1 to 13 in which the frame member has an upstanding support member at each of two rear corners, the back member being pivoted on said upstanding support members.

1 9. A chair substantially as hereinbefore described and as illustrated in Figures 1 to 3 of the accompanying drawings.

20. A chair substantially as hereinbefore described and as illustrated in Figures 4 to 7 of the accompanying drawings.

21. A chair substantially as hereinbefore described and as illustrated in Figures 8 to 10 of the accompanying drawings.

22. A hinged back and seat member adapted for use in a chair as claimed in any of claims 1 to 18.