GB2067394A - A posture chair - Google Patents

Abstract

A posture chair for the disabled comprising a base 11 and a seat 12, the seat being made up of a number of parts 13, 18, 23, 24 which together support the buttocks, back and head of a person seated in the chair, characterised in that each of the seat parts is hingedly connected to the next adjacent part or parts by hinge means which may be releasably locked to maintain adjacent seat parts in any given position relative to one another. <IMAGE>

Description

SPECIFICATION A posture chair The present invention relates to a novel posture chair for disabled persons and more particularly to a novel posture chair of th is type in which a plurality of seat portions are hingedly connected together. In another aspect the invention relates to a folding base for a wheel chair or like article.

Many disabled people and particularly people affiicted with cerebral palsy suffer to a greater or lesser degree from the inability to coordinate servoneuro/muscular relationships within the body. These people are unable to fully use their skeletal system to assist in the maintenance of "normal" body posture.

A posture seat is a chair like device designed to improve the biophysical development of the disabled by either passive support or active manipulation of the skeletal, particularly spinal posture.

Posture chairs are of particular applicability to disabled children where correct posture is essential to encourage natural skeletal growth patterns.

The present invention consists in a posture chair for the disabled comprising a plurality of interconnected seat portions, which together support the buttocks, back, and head of a person seated in the chair, each of the seat portions being hingedly connected to the next adjacent portion or portions by hinge means which may be releasably locked to maintain adjacent seat portions in any given position relative to one another.

If desired two or more of the adjacent seat portions may be connected together such that translational movement in a substantially vertical direction is possible therebetween in addition to the rotational movement possible through the hinge means.

The posture chair preferably comprises four seat portions, one for the buttocks, one for the lower back, or lumbar region, one for the upper back and shoulder region and one for the head. Each seat portion is preferably so curved in cross section as to conform generally to the contours of the body portion which it is to support. It will be recognised that chair portions of different sizes will be required for users of different physical proportions.

Each seat proportion is preferably upholstered with suitable padding materials to provide maximum comfort for a user. It is particularly preferred that at least some of the seat portions are provided at strategic locations on their inner surface, preferably under the upholstery, with flow pads, i.e. pads of material which flow under an applied pressure.

The presence of such flow pads prevents localised pressures, e.g. in the region of the pelvis or along the spine, causing skin irritation or interfering with the blood supply.

The seat portions are preferably moulded from a glass reinforced plastics material in view of the high strength to weight ratio of this material. The seat portions may however be formed from other suitable materials such as injection moulded plastics or aluminium. It is desirable that the seat portions engage a high proportion of the buttocks and back of a user and for this reason the space between the individual seat portions should be kept to a minimum. The hinge means preferably comprise lugs moulded into each seat portion which lugs can be juxtaposed with lugs on an adjacent seat portion. A bolt is then placed through holes in the juxtaposed lugs and tightened to clamp the lugs together in this desired interrelationship. If it is desired to change this interrelationship merely loosening the bolt will allow relative pivotal movement between the adjacent seat portions.

The fact that the shape of the chair can be varied by pivotal movement between adjacent seat portions allows a very wide range of chair shapes to be achieved with minimum effort. This wide variability of chair shape is most useful in that it allows therapists maximum fiexability in the adjustment of the posture of a patient using the chair. The interconnection between the seat portions themselves does away with the necessity for a supporting frame for each individual seat portion thereby reducing the weight of such a chair while enhancing its utility.

The posture chair is preferably provided with feet support means adjustably suspended from the seat portion which supports the buttocks. The feet support means most preferably comprises a tray hingedly and slidably connected to the buttock supporting seat portion. This arrangement allows considerably adjustment of the position of the feet support means relative to the rest of the chair. In an alternative embodiment two individually adjustable foot support means are provided to allow the feet of a user to be individually supported.

Posture chairs according to this invention are preferably mounted on a wheeled base however it is an advantage of the posture chairs according to this invention that they may also be used in a car or as a workplace for the patient. If the chair is mounted on a base it is preferable that it can be tilted such that the chair may be reclined from a position in which the user's back is in a substantially vertical position to a position in which the user's back is reclined by some 30".

Hereinafter given by way of example is a preferred embodiment of the present invention described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a posture chair according to the present invention; Figure 2 is a side view of the seat of the posture chair of Figure 1; Figure 3 is a detail perspective view showing the interconnection of adjacent seat portions of the seat of the posture chair of Figure 1; Figure 4 is a side elevational view of the collapsible base of the posture chair of Figure 1; The posture chair 10 comprises a base 11 on which is mounted a seat 12.

The seat 12 comprises four seat positions hingedly connected together. The seat portion 13 is moulded from glass reinforced plastic and is designed to support the buttocks of a person seated in the posture chair 10. The seat portion 13 is upholstered with an abrasion resistant layer 14 which overlies a layer of flexible foam plastic 15. In the region which will be adjacent the pelvic bones of a user the seat portion 13 is provided, between the foam plastic layer 15 and the glass reinforced plastic shell with a flow pad 16. The flow pad comprises an impervious plastic envelope 17 enclosing a mass of petroleum jelly mixed with talcum powder. This mass within the flow pad 16 has the ability to flow under an applied pressure within the confines of the envelope 17.The pressure of the user of the chair on the chair portion 13 is rendered more uniform over the area of contact between the user and the chair by the presence of the flow pad 16 and areas of normally high pressure, such as beneath the pelvic bone, are avoided thereby helping to avoid skin irritation to users required to remain in the chair for long periods of time.

Chair portion 13 is hingedly connected to chair portion 18 which is designed to support the lower back region of a user. As with chair portion 13 the portion 18 is formed of a glass reinforced plastic and is upholstered with an abrasion resistant layer 19, a flexible foam plastic layer 20 and, in the area adjacent the spine of a user, a flow pad 21.

Chair portion 23 which supports the upper back and shoulder portion of a user is hingedly connected to chair portion 18 and is also formed from a glass reinforced plastic material and is upholstered in the manner of chair portion 18. The chair portion 23 is also hingedly connected to seat portions 24 which supports the head of a user. Seat portion 24 is formed of a glass reinforced plastics material and is upholstered with an abrasion resistant layer overlying a flexible foam plastic layer.

Each of the seat portions 13, 18,23 and 24 is curved in cross section to correspond to the contours of that part of the body of a user which it is adapted to support. The seat portion being designed to extend around the body of a user sufficiently to provide lateral support as well as back support.

The posture chair 10 is provided with a foot support comprising a tray 60 moulded of glass reinforced plastic and formed with a pair of recessed portions 61 and 62 each designed to secure the foot of a user. The tray 60 is pivotally and slidably connected through clamping block 64 to a rod 63 which is in turn pivotally connected to clamping block 65 on the underside of the seat portion 13. The tray 60 may thus be raised or lowered or moved backwardly or forwardly relative to the seat 12 and additionally the tray 60 may be tilted upwardly or downwardly. These adjustments enable the foot support to be accurately positioned for any user of the chain The nature of the pivotal connections between seat positions used in this preferred embodiment of the invention is clearly shown with reference to Figure 3.The hinge means between seat portions 13 and 18 is designed to allow both translational and rotational movement therebetween while the hinge means between the other seat portions 18 and 23 and 23 and 24 is only capabie of rotational movement. Dealing first with the purely rotational connections and using the hinge between seat portions 18 and 23 as an example. The seat portion 18 is formed in the mid line of its rear surface with a pair of lugs 25 and 26 moulded integrally with the shell of the seat portions, lug 25 projecting upwardly beyond the perimeter of the shell and lug 26 projecting downwardly in like manner. A threaded metal sleeve (not shown) is moulded into each of the lugs 25 and 26 with their axes extending normally to the mid line of the chair portion. The chair portion 23 is formed with two pairs of lugs 27 and 28.Each pair of lugs 27 and 28 is spaced apart across the mid line of the seat portion and are formed integrally therewith, lugs 27 projecting upwardly above the perimeter of the seat portion and lugs 28 projecting downwardly in like manner.

The lugs 28 are spaced apart by a distance just equal to the width of lug 25 on the chair portion 18.

The pivotal connection between chair portions 18 and 23 is effected by a pair of allen headed bolts 29 and 30 which respectively extend through washers 32 and 33 and through lugs 28 into the lug 25 where they engage with the internally threaded metal sleeve moulded therein. If the bolts 29 and 30 are loosened then pivotal movement between chair portions 18 and 23 is possible, however, if the bolts are tightened the lugs 28 are clamped against the lug 25 thereby preventing relative rotational movement between those two seat portions.

Turning now to the connection between seat portions 13 and 18 the pivotable connection comprises a cranked, square section, tube 100 welded at one end to plate 101 which is severed to seat portion 18. A U-shaped bracket 102 is welded to plate 103 which in turn is screwed to seat portion 13. A pair of polycarbonate blocks 104 are positioned in face to face relationship between the arms of the bracket 102 and one end of each of the blocks against rod 105 which extends between the arms of the bracket 102 and is welded thereto. Athreaded bolt 106 extends between the arms of the bracket 102 adjacent the free ends thereof and through arcuate slots 110 in the blocks 104. The bolt 107 is provided with a cooperating nut 108 having disposed in a hole therein a tightning bar 109.The square section tube 100 extends between the blocks 104 and is received within a V-shaped groove in the mating face of each of the blocks.

Rotational and translational movement may be effected by loosening the nut 108 and respectively lifting the blocks 104 about the rod 105 or raising or lowering the tube 100. The arcuate slots 106 serve to limit the degree of rotational movement between the seat portion 13 and 18. This ensures that an inadvertent complete collapse of the seat portion 18 would not cause injury to a person using the chair as might happen if the seat portion 18 were capable of unlimited pivotal movement relative to the seat portion 13.

The seat 12 of the posture chair 10 is connected to the base 11 through a hydraulic ram 35. The piston 36 of the ram 35 is connected to a supporting plate 37 moulded into the underside of the seat portion 13 and the ram 35 is itself mounted on the hub 37 of the base 11. Ram 35 is provided with a pair of radially extending diametrically opposed cylindrical lugs 38 which are held in clamping blocks 39. By releasing bolts 41 of the clamping blocks 39 the ram 35 may be pivoted thereby causing the seat 12 attached to it to be reclined. The hydraulic ram 35 is connected to a hydraulic power source (not shown) which can be actuated to raise or lower the seat 12 of the posture chair 10. The capacity to raise and lower the seat of the chair and to tilt it is highly advantageous in that it gives greater flexibility to the chair and enables it to be used in a wider range of circumstances.Thus the chair may be used as a wash place, as a resting or sleeping place, or as an eating place for a user as well as being a mode of transport.

The base 11 is provided with four wheels, comprise ing small front wheels 51 and 52 and large rear wheels 53 and 54 which are provided with hand grips 55 and 56 respectively which can be used by a user to propel the posture chair. The wheels 51 and 52 are rotatably mounted on axles supported by stirrups 57 and 58 respectively which are in turn pivotably mounted in support blocks 70 and 71. The wheels 53 and 54 are respectively mounted on axles 72 and 73 which are in turn connected to support blocks 74 and 75.

Each of the support blocks 70,71,74 and 75 is connected to a corresponding support block 76, 77, 78 and 79, which are bolted to the hub 37 of the base 11, by a parallel motion linkage. In each case the parallel motion linkage comprises a pair of struts 80 and 81 each of which is pivotally connected at each end to one of the support blocks. The struts 80 and 81 are so connected to the support blocks that the beams bear against one another over their whole length when they are extended in a horizontal position and when they are collapsed.

In use if it is desired to collapse the base 61 the seat 12 is removed from the piston 36 and the hub 37 lifted. This allows the parallel motion linkages 80,81 to pivot downwardly, and fold inwardly and the four parallel motion linkages lie substantially parallel to one another and in close justaposition.

Braking means not shown of a suitable type may be mounted on the hub and handles 91 may be provided to allow the chair 10 to be moved by a person other than the user. The handles 91 are preferably received in sleeves 92 connected to the support blocks 74 and 75 of the parallel motion linkages at the rear of the chair.

Claims (13)

1. A posture chairforthe disabled comprising a plurality of interconnected seat portions, which together support the buttocks, back, and head of a person seated in the chair, each of the seat portions being hingedly connected to the next adjacent portion or portions by hinge means which may be releasably locked to maintain adjacent seat portions in any given position relative to one another.

2. A posture chair as claimed in Claim 1 in which there are four seat portions, one for the buttocks of a user, one for the lower back of a user, one for the upper back and shoulders of a user and one for the head of a user.

3. A posture chair as claimed in Claim 1 or Claim 2 in which each of the seat portions is upholstered.

4. A posture chair as claimed in Claim 3 in which the upholstery on at least one of the seat portions includes a flow pad on a surface of the seat portion which will be engaged by the body of a user.

5. A posture chair as claimed in any one of Claims 1 to 4 in which the hinge means comprise corresponding lugs on adjacent seat portions which are pivotally connected together and which may be clamped together in any desired pivotal relationship.

6. A posture chair as claimed in any one of Claims 1 to 4 in which foot support means are affixed to the chair.

7. A posture chair as claimed in Claim 6 in which the foot support means comprises a tray slidably and hingedly connected to the lowermost seat portion of the chair.

8. A collapsible base for a wheel chair as claimed in any preceding Claim in which the base includes lifting means adapted to support a seat such that the seat may be raised or lowered relative to the ground on which the base rests.

9. A collapsible base for a wheel chair as claimed in Claim 8 in which the lifting means comprises a hydraulic or hydropneumatic ram mounted on the hub of the base.

10. A collapsible base for a wheel chair as claimed in Claim 8 or Claim 9 in which the lifting means is pivotally mounted on the hub of the base.

11. A collapsible base for a wheel chair substantially as hereinbefore described with reference to the accompanying drawings.

12. A posture chair as claimed in any one of Claims 1 to 7 when mounted on a collapsible base for a wheel chair as claimed in any one of Claims 8 to 11.

13. A posture chair substantially as herein described with reference to the accompanying drawings.