GB2044086A - Improvements in or relating to seating arrangements - Google Patents

Abstract

The invention provides a seating arrangement, e.g. for use in a folding pushchair, comprising a frame 29, 22a, 22b supporting a seat 31 and backrest 32 hinged to the seat at 34, the seat being adjustable in the front to rear direction relative to frame member 29 and the inclination of the backrest being dependent upon the front to rear location of the seat. The backrest 32 is adjustable relative to frame members 22a, 22b by sleeves 49 slidable on members 22a, 22b and having pivot pins 50 with ball heads 51 rotatably captive in the backrest. The arrangement may further include a leg rest 33 adjustable with the seat and backrest. <IMAGE>

Description

SPECIFICATION Improvements in or relating to seating arrangements This invention relates to seating arrangements and more particularly to seating arrangements comprising a frame with a seat and back rest, adjustable relative to the frame.

It is well known in the artto provide a seating arrangement comprising a frame with a seat adjustable front to rear relative to said frame and a back rest, hingedly attached at its lower regions to the rear regions of the seat, resting against and slidable relative to a fixed transverse frame member whereby, the inclination of the back rest increases towards the vertical as the seat displaces rearwardly and reduces as the seat displaces forwardly. A difficulty with such seating arrangements is that the centre of gravity of a person using the seating arrangement varies considerably, front to rear, as the positions of the seat and back rest vary, and the frame must have substantial spacing of its ground engaging parts, front to rear, if the seating arrangement is to be stable for all seating and reclining positions of the occupant.

The present invention seeks to provide a seating arrangement including an adjustable seat and backrest, and wherein the centre of gravity is relatively stable, front to rear, for all positions of the seat and backrest.

According to the present invention there is provided a seating arrangement comprising a frame, presenting a transverse member and two generally upright members, a seat supported above said transverse member, and a backrest supported between said upright members, characterised in that said backrest is hinged at its lower regions to the rear regions of said seat, said seat is adjustable, front to rear, relative to said transverse member, and said backrest is supported by said upright members via pivotal connections the axes of which are fixed in the length direction of the backrest but adjustable in the length directions of said upright members.

Preferably the seat has at least two, conveniently three, different front to rear locations relative to the transverse member.

Preferably the different locations of the seat are determined by a cam, attached to the seat and engageable with said transverse member, and in a preferred embodiment the cam is manually rotatable between a position in engagement with the transverse member and a position disengaged therefrom.

Preferably the seat is suspended from the frame by link members, conveniently one at each side adjacent the rear regions of the seat and one at each side adjacent the forward regions of the seat, said link members are pivotally attached to said frame and, conveniently, said link members determine the inclination of the seat to the horizontal in the different seat locations relative to the transverse member.

Preferably said link members are resiliently extensible within predetermined limits.

Preferably each connection between the backrest and each upright member comprises a tubular member slidably mounted on the upright member and presenting a pin terminating in an enlarged ball head at its free end. Two half shells, secured to opposite major faces of the backrest, co-operate to house and retain the ball head therein.

In a preferred embodiment in accordance with the invention the seat comprises three rigid panels arranged in side by side relationship across the seat and hinged together, whereupon the hinges extend front to rear of the seat. The backrest also comprises three rigid panels in side by side relationship and hinged together, conveniently in vertical planes close to the vertical planes passing through said hinges of said seat.

Preferably the seating arrangement includes a leg rest hinged to the forward regions of the seat with the end regions of the leg rest remote from the seat connected to the backrest, conveniently to the pivotal connections of the backrest with its upright members, via two flexible tie members arranged, when the seat is in its foremost position, to lie above the plane of the seat, whereby to support the leg rest above the plane of said seat.

Preferably the foot rest comprises three rigid panels in side by side relationship connected together by hinges in vertical planes close to the vertical planes passing through the hinges ofthe seat.

Preferably the backrest and seat and, when provided, the leg rest are integrally formed from a single sheet of plastics material, conveniently, polypropylene, and the hinges between said members and the hinges along said members are formed by areas of reduced thickness in said sheet.

The seating arrangement proposed by this invention is particularly suitable for use with a childs folding push chair and according to this embodiment the frame includes front and rear legs mounted on wheeled axles, the two upright members have their upper regions turned towards one another to form a handle, or handles, and the frame includes pivotal connections by which, in a folded condition, the front and rear legs and the seat can lie in generally parallel adjacent relationship.

When the seat and backrest and, when provided the leg rest each have two hinges in generally similar planes the seat support arrangement is particularly suited for use with push chairs wherein, after folding front to rear, the chair can fold transversely, about two planes parallel to, but spaced inwardly from, the side faces of the chair.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Figure 1 shows, in perspective view, a seating arrangement in accordance with the invention applied to a foldable push chair.

Figure 2 shows a centre line cross section through the arrangement shown in Figure 1.

Figure 3 shows, in perspective exploded view, the cam assembly for the seating arrangement.

Figure 4 shows, in front view, the arrangement for supporting the backrest.

Figure 5A, Band Cshows, in diagrammatic side view, the three different positions for the backrest, seat and leg rest of the seating arrangement, and Figure Gshows, in perspective view, the backrest, seat, and leg rest in the fully reclining position.

In the illustrated example a frame for a foldable pushchair comprises two rear legs 11 and 12, connected by a trasverse member 13, two front legs 14 and 15, connected by a transverse foot rest 16, an arm rest 17 into which the upper ends of legs 11 and 14 enter and are pivotally retained, an arm rest 18 into which the upper ends of legs 12 and 15 enter and are pivotally retained, a side rail 10 pivotally attached to legs 11 and 14 at spaced locations below arm rest 17, a side rail 21 pivotally attached to legs 12 and 15 at spaced locations below arm rest 18, and a handle 22, the limbs 22a and 22b of which have their lower ends pivotally attached to legs 11 and 12 respectively and to arm rests 17 and 18 respectively.

In fact, the lower region of limb 22b is connected to leg 12 by two bell crank levers 23 and 24, one at each side of the junction of limb 22b and leg 12, and a pivot pin 25 passes through leg 12 and through the lower regions of both bell crank levers 23 and 24 and a pivot pin 26 passes through limb 22b and through the upper regions of bell crank levers 23 and 24.

The limb 22a is connected to leg 11 in identical manner to the connection of limb 22b with leg 12.

The limbs 22a and 22b extending upwardly and rearwardly from their respective connections with bell crank levers 23 and 24 pass through the rear regions of arm rests 17 and 18 respectively and are pivotally connected thereto by pivot pins 27 and 28 respectively.

A transverse member 29 extends between side rails 20 and 21 just rearwardly ofthe pivotal connections of rails 20 and 21 with legs 14 and 15 respectively, and legs 11,12, 14 and 15 have double-wheeled axles 30, secured on their respective lower ends.

An integral seat 31, backrest 32 and leg rest 33 made from a single sheet of polypropylene has a hinge 34 formed at the junction of seat 31 with backrest 32 and a hinge formed at the junction of seat 31 with backrest 33, said hinges 34 and 35 being formed by areas of reduced thickness of the sheet, the reduced thickness being such as to permit the sheet to bend readily at said hinge locations.

The seat 31 has a cam assembly mounted on its undersurface and comprising a channel-shaped cam support member 36, a cam 37, and a maual actuating lever 38.

The support member 36 has its bridge part 36a attached to seat 31 by screws or rivets (not shown) engaging in bores 36b, in bridge 36a and the parallel limbs 36c and 36d of members 36 depend downwardly from bridge part 36a and have axially aligned bores 36e and 36f respectively.

The cam 37 comprises a cam spindle 37a of an axial length slightly less than the inside distances between limbs 36c and 36d, an axial etension 37b which engages in bore 36f in limb36dand a blind bore 37c in its end remote from extension 37b. The cam spindle supports a cam blade 37dwith three cam recesses 37e, 37fand 37g in that edge remote from the spindle 37a.

The manual actuating lever 38 comprises a handle part 38a with a spindle 38b extending therefrom and which passes through the bore 36e in limb 35c and into the blind bore 37c in the cam spindle to maintain the cam 37 captive between the limbs 36c and 36d of member 36 whilst allowing the cam to rotate about the axis passing through bores 36e and 36f.

A pin 39 passes through a transverse bore 37h in cam spindle 37a and through a transverse bore 38c in spindle 38 to lock the actuating lever 38 with cam 37.

The free end of extension 37a projects outwardly from limb 36dand has its cross section reduced to rectangular form. The limb 37a has two leaf springs 39 and 40 anchored thereto and which pass one on each side of the rectangular section of extension 37a and are tensioned toward extension 37a so as to resiliently retain the cam 37 with the cam blade 37d in the vertical plane (when the cam assembly is in use) or at right angles thereto.

In use, the seat 31 with the cam assembly secured to its undersurface is mounted on the frame with the transverse member 29 between bridge 36a and cam 37 so that, by deflecting the cam blade to the horizontal plane, the cam assembly and seat 31 can slide relative to member 29 between the limits defined by limbs 36c and 36d.

The cam assembly, and thereby seat 31, can be locked in any one of three front to rear positions for seat 31 by rotating the blade 37dto locate the member 29 in the desired one of cam recesses 37e, 37f or 37g.

To change the front to rear location of the seat from one location to another it is only necessary to turn handle 38 to bring blade 37dto a horizontal position and push seat 31 until the desired cam recess is vertically aligned with member 29 when the handle can again be turned to lock member 29 in the desired cam recess.

The seat 31 is suspended from the arm rests 17 and 18 by suspension members 41 and 42, pivotably anchored at their upper ends to pivot pins 43 and 44 respectively and which connect rear legs 11 and 12 to arm rests 17 and 18 respectively, and the lower regions of members 41 and 42 pass through apertures 31a and 31b respectively, in the rear corners of seat 31 and have enlarged ends beneath said seat and upon which seat 31 can rest. Two further suspension members 45 and 46 are pivotably anchored respectively on pivot pins 47 and 48, pivotally retaining front legs 14 and 15 with arm rests 17 and 18, respectively and the members 45 and 46 pass through apertures 31 c and 31 din the forward corner regions of seat 31 and have enlarged ends upon which the seat 31 can rest.

Thus, as the seat 31 is suspended by members 41, 42,44and 45 the inclination of the seat to the horizontal will be different for the three front to rear locations of the seat determined by the engagement of members 29 with the cam recesses 37e, 37fand 37g.

The limb 22a of handle 22 has a tubular member 49 slidably mounted thereon and member 49 has an axis pin 50, terminating in an enlarged ball head 51.

extending therefrom. The backrest 32 has two identical half shells 52 and 53 secured to its opposite major faces, and defining internal recesses (not shown) which embrace and retain the ball head 51.

As will be seen from Figure 6 the backrest 32 has an edge recess 32a to accommodate that part of the ball head 51 between half shells 52 and 53. In identical manner the limb 22b has a tubular member 49 slidably mounted thereon, the member 49 presents an axis pin 50 terminating in an enlarged ball head 51, and the ball head locates in an edge recess 32b in backrest 32 and is captive between two half shells 52 and 53 secured on opposite major faces of the backrest 32.

Tie members 54 and 55, pivotally anchored to the axis pin 50 extend therefrom to the lower corner regions of leg rest 33 and these tie members 54 and 55 have specific maximum lengths as will become apparent hereinafter.

The suspension members 41,42,45 and 46 and, conveniently also tie members 54 and 55, are preferably composite members arranged to extend resiliently between minimum and maximum length condition.

With the above described seating arrangement and with the transverse member 29 locked in cam recess 37c, the seat 31, backrest 32 and leg rest 33 are approximately in the positions shown in Figure 2 and Figure 5A. In this rearmost position for seat 31 the suspension members 41 and 42 resiliently support the rear regions of seat 31, suspension members 45 and 46 are unloaded and at minimum length, and the seat 31 supports the backrest 42, pivotable about the axes of pins 50, in a relatively upright position. In this position the leg rest hangs substantially vertical beneath the forward edge of seat 31, with the tie members 54 and 55 just in tension.

When the transverse member 29 is in recess 37f the parts are in the positions shown in Figure 5B with seat 31 in its mid-front to rear positions. The suspension members 41,42,45 and 46 are under low tension to balance the seat 31 but prevent undue rocking of seat 31 on member 29. When seat 31 is in this position the backrest 32 is in a partially reclined position and leg rest 33 may, depending upon the tension in members 54 and 55, lie vertically beneath the front edge of seat 31 or have its lower regions drawn slightly forward therefrom.

When transverse member 29 is in recess 37g the seat 31 is in its forward most position (Figure 5C), its forward regions are supported by suspension members 45 and 46, sliding tubular members 49 on limbs 22a and 22b are in their lowermost positions and backrest 32 is therefore in a fully reclined position. In this position the rear portions of seat 31 are positively supported by member 29, suspension members 45 and 46 are at their maximum length conditions and suspension members 41 and 42 are at, or close to, their maximum length conditions so that a stable support for seat 31 is obtained.With seat 31 and backrest 32 in the fully reclined position the paths from axis pins 50 over the front edge of seat 31 to the remote corners of leg rest 33 are greater than the maximum extensible lengths for tie members 54 and 55 so that, as the seat 31 and backrest 32 are to displace to the fully reclining position, the leg rest 33 will be elevated until the free end of leg rest 33 is above the plane of seat 32. Thus, as will be seen from Figure 5C, the tie members 54 and 55 support leg rest 33 above the plane of seat 31 to define a fully reclined condition for seat 31, backrest 32 and leg rest 33.

It will also be apparent from Figures 5A, 5B and 5C that as seat 31 moves forwardly from its rearmost to its foremost position the pivotal axis of the backrest lowers and advances relative to the chair frame and, as in its fully reclining position the backrest will receive its maximum loading, the leg rest is elevated so that, for all conditions of the seat supporting arrangement, the centre of gravity of the chair and its occupant always lies in a vertical plane passing between the wheel axles 30 and in fact varies little from the mid vertical plane between said axles, whereby a stable seating arrngement is obtained.

As the legs 11, 12, 14 and 15 are pivotally attached to arm rests 17 and 18 and side members 20 and 21 and as handle 22 is pivotally attached to arm rests 17 and 18 and legs 11 and 12 the arrangements to the said pivotal axes are so spacially arranged, as is well known in the art, that the frame can fold front to rear by simply elevating the forward regions of arm rests 17 and 18 until said arm rests lie almost parallel with handle 22 when the legs 11,12, 14 and 15 will also have pivoted into planes substantially parallel to handle 22.

As the frame folds as defined above the seat 31 pivots about hinge 34 to lie generally parallel with backrest 32 and the leg rest may be pivoted over to rest on seat 31 before the frame is folded so that leg rest 33 lies parallel to seat 31 and between seat 31 and backrest 32 in the fully folded position for the frame.

Further, and as is now known in the art, the tranverse members and elements of the frame, namely the handle 22 between limbs 22a and 22b, transverse member 29, transverse member 13 and transverse foot rest 16, may have hinge joints identified by letter "A", in two parallel planes and which permit the folded side assemblies of the frame to be turned inwardly towards one another, thus to greatly reduce the transverse width of the folded pushchair. When the frame includes this facility the backrest 32, seat 31 and leg rest 33 have hinges B and C in the transverse folding planes of the frame so that said backrest 32, seat 31 and leg rest 33 can fold transversely with the frame.

Although the present invention has been described by way of example with reference to a specific embodiment the invention is not limited thereto and many modifications and variations, particularly to the frame arrangement supporting the seat and backrest, will be apparent to persons skilled in the art.

Claims (18)

1. Aseating arrangement comprising aframe presenting a transverse member and two generally upright members, a seat supported above said transverse member, and a back-rest supported be tween said upright members characterised in that said back-rest is hinged at its lower regions to the rear regions of the seat, said seat is adjustable, front to rear, relative to said transverse member, and said backrest is supported by said upright members via pivotal connection, the axes of which are fixed in the length direction of the back-rest but adjustable in the length direction of said upright members.

2. A seating arrangement as claimed in claim 1 in which said seat has at least two different front to rear locations relative to said transverse member.

3. A seating arrangement as claimed in claim 1 or 2 in which a cam is secured to the seat and presents a plurality of different engagements with the transverse member, each of which engagements defines a position for the seat relative to said transverse member.

4. A seating arrangement as claimed in claim 3 in which the cam comprises a cylindrical body, arranged with its axis generally parallel to the plane of the seat and extending in the front to rear direction of said seat, said cam being displaceable between a first condition, wherein the seat can displace in the front and rear directions relative to said transverse member, and a second condition wherein the cam retains the seat in a selected one of a plurality of fixed positions relative to the transverse member.

5. A seating arrangement as claimed in claim 4 in which the cam is rotatably supported adjacent its ends by a bridge secured to the underside of said seat, the transverse member passes between said cam and said bridge, and said cam presents a radial cam blade defining a plurality of recesses spaced apart along its free edge and each of which recesses is capable of receiving the transverse member therein to define a fixed position of the seat when the cam is rotated so that the cam blade lies in a substantially vertical plane adjacent the seat.

6. A seating arrangement as claimed in claim 5 including means for retaining said cam with the cam blade adjacent the seat and in a vertical plane.

7. A seating arrangement as claimed in any preceding claim in which the seat is suspended from the frame by four link members which engage the seat one to each side region of the seat at or towards the rear of said seat and one to each side region of the seat at or towards the front of the seat.

8. A seating arrangement as claimed in claim 7 in which said link members are pivotally attached to said frame.

9. A seating arrangement as claimed in claim 7 or 8 in which said link members are resiliently extensible within predetermined limits.

10. A seating arrangement as claimed in any preceeding claim in which the connection between the back rest and each upright member comprises a tubular member, slidably mounted on the upright member.

11. A seating arrangement as claimed in claim 10 in which each connection between a tubular member and the back-rest comprises a pin extending from the tubular memberwith an enlarged ball head on its free end and two half shells fixed with respect to the back-rest and adapted to rotatably retain the ball head captive therebetween.

12. A seating arrangement as claimed in any preceeding claim in which the frame is foldable, front to rear, from its condition of use to a folded condition of reduced front to rear dimensions.

13. A seating arrangement as claimed in any preceeding claim in which all the transverse members of the frame include two pivotal connections, said pivotal connections lie in common planes when the frame is in its front to rear condition, and whereby the side regions of the seating arrangement outwardly of said pivotal connections can be pivotally displaced towards one another to lie substantially to right angles to the part of the arrangement between the planes of the pivots, thereby to reduce the transverse dimensions of the seating arrangement.

14. A seating arrangement as claimed in claim 13 in which the seat and back-rest comprise rigid panels, hinged together in such manner that said hinges lie substantially along the planes of the pivotal axes for the frame, whereupon when said frame is folded transversely the rigid side panels of the seat and back-rest are folded with the side regions of the frame and the rigid side panels of the back-rest embrace the folded panels of the seat.

15. A seating arrangement as claimed in any preceeding claim including a leg rest, pivotally attached to the front edge region of the seat, and tie members extending between the corners of the leg rest remote from the seat and the pivotal connections of the back-rest with said upright members, said tie members serving to retain said leg rest outstanding from said seat with the plane of the leg rest inclined upwardly from the leg rest connection with the seat.

16. A seating arrangement as claimed in claim 15 in which the leg rest comprises panels of rigid material hinged together and, when the frame is in its folded condition front to rear, said hinges lie in planes which allow the side regions of the leg rest to pivotally displace with the movement of the side regions of the frame as said side regions displace towards a folded transverse condition for the frame.

17. A seating arrangement as claimed in any preceeding claim in which the seat and back-rest, and when provided a leg rest, are formed integral from a single sheet of plastics material and the hinges between said seat, said back-rest and said leg rest, and the hinges joining the rigid panels defining the seat, back-rest and leg rest are formed by locally reduced thicknesses in the sheet material.

18. A seating arrangement substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.