GB2369566A - Support seat for the disabled - Google Patents

Abstract

The seat support of, eg a wheelchair, is pivotally mounted for both tilting, by means of a retractable cylinder 26, and vertical movement, by means of a parallel motion mechanism 32 driven by retractable cylinder 38. The seat support 24 may additionally be pivotally connected to a further support (28, Fig 2) which includes individually positionable lateral supports (40,42,44,45) for various parts of the body. The pivotal connection to the seat support uses a guide and a slide clampingly received within it, each pivoted to one of the seat and further support. The seat has individual left and right parts which are backward/forward slidable, each part carrying a height adjustable footrest. A body support member (101, Fig 5) comprises an elongate flexible and resilient sheet of plastics material having a series of parallel and equidistant recesses cut into it.

Description

SUPPORTIVE SEAT

The present invention relates to a seat, particularly, but not exclusively to a seat adapted for supporting a disabled person. The seat is particularly suitable for a person with cerebral palsy or a paraplegic or quadriplegic disability or other related disabilities. Also, the seat is particularly suitable for children with the aforesaid disabilities.

Traditionally, disabled people and particularly children are seated in conventional supportive (wheel) chairs which are based on a modified seat structure which partially encloses the user. These conventional seats are not only bulky and visually unappealing, but also they have limited adjustability which makes them uncomfortable to the user.

These chairs are generally adapted to the user by means of expensive tailor-made adaptations. Further, due to their weight and size, these chairs are generally not suitable for daily use in the house, school or work place.

It is therefore desirable to provide an improved supportive seat which addresses the above described problems and/or which offers improvements generally.

According to a first aspect of the present invention there are provided a supportive seat, a body support element, a positioning means and a wheelchair as defined in the accompanying claims.

In an embodiment of the invention there is provided a supportive seat comprising means for seating a user, a structure for supporting said seating means and a base for supporting said support structure from the ground. The supportive seat may further comprise means for tilting the support structure relative to the base and means for adjusting the height of the support structure relative to the base.

We have discovered that particularly forward tilting of

the user has important therapeutic advantages. Forward tilting of a disabled person enables the spine to be positioned in a more favourable position which allows it to fully extend and to use minimal energy whilst seating.

Height adjustment allows adaptation of the seat to desired heights for sitting at a desk or table. In this respect it is important to provide a strong and reliable mechanism, since throughout the life of the supportive seat, the height adjustment mechanism is operated frequently.

In an embodiment of the invention the tilting means may comprise a first extension means which may be activatable for tilting the support structure relative to the base. The support structure may comprise a first support member and one or more further support members. The further support members may comprise a second and a third support member.

The first support member may be pivotally connected to a further support member. The first extension means may be provided between said first support member and said second support member. In a preferred embodiment the first extension means is pivotally connected to both the first and second support member.

In an embodiment of the invention, the height adjustment means may comprise a linkage structure which interconnects the base and the support structure. The height adjustment means may further comprise a second extension means which is arranged between said base and said support structure. An advantage of this linkage structure is that the seat can be conveniently moved between a lower and a higher position by the second extension means. Furthermore, the second extension means may be arranged relative to the base such that they operate at maximum efficiency.

The base may comprise a base member. The linkage structure preferably comprises a first and second linkage member, each member being pivotally connected to the base member and the first support member, said base member and

said first support member being parallel and extending approximately vertically towards one another. The respective linkage members are parallel so that a parallelogram linkage structure is formed. In this way it is achieved that the seat is adjustable to various different heights whilst the support structure is substantially movable in a vertical plane.

The first extension member is preferably pivotally connected to the first linkage member and the first support member. The second extension means may be pivotally connected to the first support member or to the second linkage member. Alternatively, the first and second linkage members may be arranged in pairs on either side of the respective base member and first support member. An important feature of the parallelogram linkage structure is that a line extending through the pivotal connections of the first linkage member on the support member and the base member is parallel to a line extending through the pivotal connections of the second linkage member on the support member and the base member.

The linkage members may be of any shape. However, the linkage members are arranged so that imaginary lines through the pivotal connections on the base and the support structure form a parallelogram structure.

In an embodiment, the second extension means may be connected to the first support member. The force necessary to lift the seat is reduced in this way and is approximately equal to the combined weight of the seat and the user. This allows the application of less powerful extension means such as for example electric drive motors. The second extension means directly connected to the first support member obviates the need for a second linkage member. However, sideways movements on extension means are undesirable since this can cause wear.

In a preferred embodiment the second extension means

may be pivotally connected to the base member and the first linkage member. The second extension means may be pivotally connected to the first linkage member approximately equidistant from both pivotal connections of said first linkage member. In this way the force necessary for lifting the seat is approximately twice the weight of the seat (and the person supported by the seat when the seat is in use).

The increased force necessary for lifting the seat improves the performance of extension means in the form of gas/spring operated cylinders. These are usually too powerful for directly lifting the seat and the person supported by the seat when the seat is in use. The position of the extension means at the mid point between of the pivotal connections on the linkage member cushions the movement of the extension means. Also, the construction of the height adjustment mechanism is more compact.

In a preferred embodiment the second extension means may comprise one or more extension members. Particularly when the supportive seat is seating adults, two extension members may be provided for lifting the support structure.

This allows heavier users and/or heavier support structures to be lifted. The extension members may comprise a power-up, gravity-down cylinder which may be formed by a pneumatic cylinder and/or hydraulic cylinder and/or a sprung cylinder or combinations thereof. Furthermore, the extension means may be formed by an electrical extension member comprising an electric drive mechanism. This mechanism may be operable by both the user and/or operator of the supportive seat.

In another embodiment of the invention the seating means may comprise one or more seat elements. The support structure may comprise a second member for supporting one or more seat elements and said structure may further comprise a third support member for supporting one or more seat elements. In a preferred embodiment the seat elements are removably mounted on the support structure. The removable

seat elements allow individual cleaning or replacement of these elements.

In a further embodiment of the invention the second and third support member may be pivotally interconnected and one or more first positioning means may be provided for positioning the third support member relative to the second support member. The first positioning means may comprise a first guide member and a first member being slidably arranged inside said guide member, said first guide member comprising securing means for securing said first slidable member into position. Said first guide member may be pivotally connected to a support member and said slidable member may be pivotally connected to another support member. The first guide member may comprise a block member to prevent the first slidable member from sliding out of the guide member.

In an embodiment the first guide member may comprise a recess and the first securing means may comprise clamp means which are engagable with at least part of the first slidable member at least partially in said recess, the securing means further comprising activating means for activating and releasing said clamp means. In a preferred embodiment the clamp means are arranged in a further guide member comprising a further recess or slot which is provided perpendicular to the guide member such that the further recess corresponds at least partially with said recess. The clamp means may comprise one or more clamp members. The clamp members may be in the form of bushes, pads, grippers, or any other suitable form. The activating means may comprise a thread and a rotating member for rotating said thread, the clamp members being engageable with said thread such that said members are releasable and engageable with the first slidable member by operating the rotating member.

The first guide member and further guide member may be in the form of a tube such as a tube of a circular cross

section. The recess and further recess may comprise a slot or an opening of an approximate circular shape. The activating means may be in the form of a suitable bolt or a screw type thread. A rotating member may be in the form of a lever or knob or nut or any other form which allows the operator to conveniently operate the activating means.

In another embodiment of the invention the first positioning means may comprise a first positioning member provided on the second support member and a second positioning member provided on the third support member. The first positioning member may comprise one or more receiving members in the form of recesses and/or holes. The second positioning member may comprise an engaging member for engaging with the receiving members. The engaging member may comprise a retractable projection for engaging with the receiving members and a member for operating the projection. The operating member may comprise a control member for controlling the operating member. The control member may be operable between a first position in which the projection is retracted and a second position in which the projection is retractable. The projection may be retracted by pulling the operating member in the form of lever or a knob away from the support members.

The second support member may comprise a frame member and one or more seat support elements for supporting the seat elements, the seat support elements being slidably arranged relative to the frame. The frame may comprise a second guide member. The seat support element may comprise a second slidable member such that the second slidable member is slidably arranged inside the second guide member.

The second support member may further comprise a seat positioning means for positioning the seat elements relative to the frame in a desired position. An advantage of this arrangement is that suitable support can be provided to the user where needed. The seat element may extend from the

front of the seat underneath the back of the supportive seat so that the seat elements are sufficiently long for extending these elements without compromising the seating comfort of the user. For example, to provide additional support under the thigh or upper leg, the seat element can be extended or retracted depending on the user's requirements.

In a further embodiment of the invention the third support member may comprise means for adjusting and/or positioning one or more back seat elements. The third support member may further comprise one or more lateral supports for providing lateral support to the user. This is particularly important to prevent the user from accidental sideways movements. This is particularly important to quadriplegics and people suffering from cerebral palsy.

Lateral support may be provided at various heights along the third support member: at shoulder height to support the shoulders, at thoracic height to support the rib cage and at hip height to support the pelvic girdle and hips.

In an embodiment of the invention the lateral supports may comprise one or more lateral positioning means for adjustment of the lateral support in a direction approximately parallel to the third support member and in a direction approximately perpendicular thereto. The lateral support may further comprise lateral securing means for securing the lateral positioning means in place. This allows complete adjustment of the lateral support so that support can be provided where necessary to the user. Furthermore, the lateral supports may also be pivotally arranged around an approximate vertical axis. Depending on the requirements of the user, this allows the supports to be movable between an in-use user supporting position and an unsupporting position in which the supports are rotated away from the user. Again, further support securing means may be provided for securing the lateral supports in place.

In another embodiment of the invention each lateral support may comprise a flexible member. The flexible member may comprise a sheet of flexible material comprising a plurality of substantially parallel linear recesses applied on one side or both sides of the flexible material to improve the flexing properties of said material. The elastic properties of the material allow it to return to its approximate flat shape. The recesses locally weaken the flexible material so that this material comprises additional flexing properties in addition to the flexing properties which are inherent to the material and related to the material properties. The recesses make the material less resilient and therefore more comfortable to a user. Further, since the construction of these lateral supports is extremely simple, these supports can be manufactured efficiently and cost effectively. In an embodiment, the body support element or lateral support may comprise a flexible material, the material comprising an inherent stiffness. The material further comprises slots or recesses generally in line with each other and parallel to an axis along which bending is to occur for enabling the material to conform to the body under a modest load whilst providing adequate support to the body.

The lateral supports may comprise a padding material and/or a suitable cover material which is provided over the flexible member so that the supports are comfortable to the user. Suitable padding material may comprise foam or multiple layers of a soft material. Further, the sheeted material may be shaped such that the outer perimeter has a shape which is more comfortable to the user.

The base may comprise one or more transport members in the form of wheels. These wheel may be fitted with brakes so that the supportive seat can be conveniently repositioned and located in fixed position. Preferably, the transport members comprise castor wheels. Furthermore, foot plates may

be provided for supporting the foot of the user. The foot plates may be provided on the seat elements so that upon extending a seat element, the foot plate moves therewith.

This enables the feet and/or lower legs of the user to be adequately supported. Knee supports may also be provided in the form of knee blocks which fit snugly around the knees and/or lower legs of the user. These knee blocks are an effective way of supporting the knees of a user. The knee supports may be slidably arranged both in an approximate horizontal plane and in an approximate vertical plane to position the supports relative to the user. In a preferred embodiment the knee supports are slidably arranged relative to the second support member. The knees supports may also be arranged such that these can be pivoted away and towards the second support member.

According to another aspect of the invention there is provided a body support comprising any novel combination of features thereof described herein. The body support may be provided on a supportive seat for supporting a user.

According to a further aspect of the invention there is provided a positioning means comprising any novel combination of features thereof described herein.

According to a further aspect of the invention there is provided a wheelchair comprising any novel combination of features thereof described herein.

There are thus provided aspects of the invention relating to a supportive seat, a positioning means, a wheelchair, and a body support.

In an embodiment of the invention there is provided a supportive seat with multiple functionality. The supportive seat can be used for various applications such as a household application where the seat is simply used as multipurpose seat to a disabled user, a car seat or a general purpose seat. The supportive seat may comprise arm

rests and a table top may be mounted onto the arm rests to provide a desk surface to the user. The arm rests can be adjustable in height and the arm rests can also be tiltable.

The supportive seat comprises a base, a support structure and seating means which are provided onto the support structure. The seating means comprises seat elements which are removably mountable onto the support structure so that these can be removed if desired or exchanged for seat elements which are tailored to specific user requirements.

An advantage of this particular seat is that it can provide support to users with a wide range of disabilities.

Due to its large range of extendable supports it can be adapted to the requirements of any user.

The seating means are adjustable in height relative the base and can also be tilted to required inclinai The tilting range extends from approximately 15 degree forwards to approximately 40 degrees backwards. We have discovered that tilting of the seat can be beneficial to users with particular disabilities. Particularly forward tilting appears to be therapeutic to users which have a condition such as cerebral palsy. The forward tilting allows the spine to fully extend which allows the user to consume minimum energy whilst seating. The extended spine allows the thoracic cadge to expand which improves breathing of the user and thus the user's overall well being.

The support structure comprises three support members which are pivotally interconnected. A parallelogram linkage construction interconnects the base and the first support member. The base comprises a base member and a support member which are substantially parallel and are movable in approximate vertical sense relative to one another. Linkage members are provided between the base member and the support member which are parallel. In this way a parallelogram linkage construction is achieved. A first cylinder in the form of a power-up, gravity-down cylinder is pivotally

arranged between the upper linkage member and the base. This cylinder is activated by means of an activating means which is activated by means of a handle provided on the support structure. A further cylinder including activating means is pivotally arranged between the first support member and the second support member. This allows the second support member to be tilted relative to the first support member. This cylinder is operable in a similar fashion to the first cylinder.

In a preferred embodiment activating members operate the cylinders. The cylinders comprise blocking means which are releasable by the activating members. The activating members comprise a cable connected to the blocking means; the cable is further connected to an operating lever which is similar to a handbrake on a bicycle. Upon activation of the lever, the cable releases the blocking means on the cylinder which allows the cylinder to extend. If the first cylinder is operated in this way, the supportive seat is lifted to a higher position whereas operation of the second cylinder allows the seat to tilt backwards or to be tilted backwards. The seat can be returned to its original position by releasing the blocking means and pushing the seat down and/or tilting the seat forwards to retract both/each of the cylinders.

The third support member can again be tilted relative to the second support member so that the person seated in the seat can enjoy a reclined position as well as an upright position. The reclined position is useful if the person wishes to relax certain neck muscles or wishes to take a nap. A positioning means is provided on the second support member including a securing member for securing said positioning means in place to allow the third support member to be positioned in a desired position. This positioning means comprises a slideable member in the form of a rod or tube which is slidably arranged in a guide member in the

form of a tube. The guide member comprises a recess or opening in which the slideable guide member is partly exposed. Clamp members in the form of bushes are present which can engage with the guide member in the recess. In the preferred embodiment the clamp members are arranged in a further tube which is mounted onto the guide member perpendicular thereto such that the aperture of said further guide member corresponds with the recess of the guide member. The clamp members are preferably provided on a screw-like thread. The thread can be rotated by means of a lever, a screw type fitting or a nut so that the clamp members can be activated or released as desired.

The second support member further comprises seat support elements which are slidably arranged relative to the second support member. This allows the seat elements to support the user adequately. If desired, for instance to provide additional support to a leg, one of the seat elements can be moved forwards or backwards relative to the support member.

The third support member may comprise means for moving the seat elements in a direction approximately parallel to the third support member to provide adequate back support to the user. A neck/head support may further be provided. This neck/head support may be arranged such that this can be adjusted to the user's requirements. Further lateral supports may be arranged in such a way that these are slidable in both vertical and horizontal direction relative to the third support member to provide adequate support to a user. The lateral supports may be provided in three sets to support both the shoulders of the user, the thoracic cage of a user and the hips and/or the pelvic girdle of the user. These supports prevent undesired lateral movements or sideways movements of the user. The supports are particularly useful when supporting people with cerebral palsy or related conditions.

The second support member may comprise one or more further supports in the form of arm supports which may be both adjustable in height and rotatable around an approximate horizontal axis. These arm supports can support further aids and/or elements which may be added to the supportive seat, such as a table top, a desk surface, a toy rack, an activity frame or additional supports in whatever form they may be.

The third support member may further be provided with a handle which is useful when transporting the supportive seat. Furthermore, the handle is useful for adjusting the seat such as the height and/or inclination of the seat.

The supportive seat can further comprise foot supports, knee supports, additional head supports and other supports which can aid in providing further support to the user or adding to the comfort of the user.

The present invention will now be described by way of example only with reference to the following drawings in which: Figure 1 presents part of a supportive seat according to an embodiment of the invention; Figure 2 presents part of the rear of the supportive seat of Figure 1; Figure 3a presents a height adjustment means in an embodiment of the invention in which the seat means is in a low position; Figure 3b presents the height adjustment means of Fig.

3a in which the seat means is in a high position; Figure 3c presents movable seat elements of the

supportive seat in an embodiment of the invention ; Figure 4 presents positioning means for a support member which comprises clamp means in an embodiment of the invention; Figure 4a presents a diagrammatic side view of part of the positioning means of Fig. 4 from which the clamp means are removed; Figure 5 presents a diagrammatic perspective view of part of a lateral support in an embodiment of the invention, and; Figure 6 presents a diagrammatic side view of a supportive seat without seat elements in another embodiment of the invention.

The supportive seat 10 comprises a structure 12 for supporting seating means 13 and a base 14 for supporting the support structure 12 from the ground. The support structure 12 comprises a first support member 22, a second support member 24 and a third support member 28 (Fig. 1-3a, b).

The supportive seat further comprises means 16 for tilting the seat support structure 12 relative to the base 14. The tilting means 16 comprises a pivotal connection member 20 which is provided between the first support member 22 and the second support member 24. The tilting means 16 also comprises an extendable cylinder 26 which is pivotally connected to the respective first and second support members 22,24 for tilting the seat means 13 relative to the base 12.

The extendable tilting cylinder 26 may comprise a push up, gravity-down cylinder which is conventionally used in wheel chairs. This cylinder has a release means (not shown) which when operated releases a blocking mechanism (not shown)

which is built-into the cylinder so that the cylinder can extend or retract. The cylinder can be retracted by pushing the seat support structure forwards upon releasing the blocking mechanism. The release means are operated by means of a cable connected to a lever 30 which is located onto the third support member. This lever 30 is of a common type which is conventionally found on for example bicycles for operating cable operated brakes (Figs. l, 2,3a, 3b).

The support seat 10 further comprises a height adjustment mechanism 18 which comprises a parallel linkage structure 32 which interconnects both the base 14 and the first support member 22. The parallelogram linkage structure 32 consists of two pairs of parallel linkage members 33,34 which are pivotally connected to both a base member 36 and the first support member 22 at respective pivotal connections. A cylinder 38 of a similar type as herein before described is applied between the linkage member pair 33. The cylinder 38 is pivotally connected to the upper linkage member 34 and is also pivotally connected to the base 14. The cylinder 38 is connected approximately halfway between the pivotal connections to the base member 36 and the first support member 22. The cylinder 38 is operated by lever 31 in a similar way as hereinbefore described.

The seating means 13 comprises seat elements which are removably mounted onto the seat support structure 12. This allows the seat elements to be individually adapted to the requirements of the user. Also, the elements can be individually replaced and/or cleaned.

The third support member 28 in particular is provided with lateral supports in various places relative to the user's body. The first pair of lateral supports 40 provide support to the lower body, in particular to the hips, the upper legs and the pelvic girdle of the user. The second pair of lateral supports 42 provide support to the thoracic cage or rib cage of the user; whereas the third pair of

lateral supports 44 provide support to the shoulders of the user. In addition, a head rest or neck support 45 is also provided. These particular supports 40,42, 44,45 allow the supportive seat to be used for seating people with a wide variety of disabilities including cerebral palsy. Each individual support comprises positioning means for positioning the support in a desired position depending on the user's requirements. One or more securing means are further provided for securing each of the positioning means.

The second and third support member 24,28 are pivotally interconnected. The supportive seat structure 12 further comprises one or more positioning means 46 for positioning the third support member 28 relative to the second support member 26 (Fig. 4, 4a). The first positioning means 46 comprises a first guide member 50 and a first slidable member 48 in the form of a rod or tube which is slidably arranged inside the first guide member 50 which is pivotally connected to the second support member 26. The first guide member 50 comprises a recess 56 which partially exposes the first slidable member 48. Perpendicular to the first guide member 50 a tubular member 52 comprising a further recess or slot is mounted onto the first guide member 50 over the recess 56. The first positioning means 46 comprises first securing means for securing the first slideable member 48 in a desired position. The first securing means comprises clamp means. Inside this tubular further guide member 52 the clamp means are slidably arranged for engaging with the slidable member 48 so that the slidable member 48 can be fixed in place to secure the third support member 28 or back seat in the desired position. The clamp means may comprise clamp members (not shown) which may comprise bushes and are arranged on a screw-type thread which allows these clamp members to be released and engaged by rotating lever 54. The positioning means 46 are pivotally connected to the respective second

and third support members 24 and 28 by the respective portions 58 and 60 in which a pivotal connection can be arranged.

The second support member 26 comprises a frame in which the seat elements 60 and 62 are slidably arranged. This allows the seat 13 to provide adequate support to the upper legs and/or other body parts. The individual seat elements 60 and 62 are each mounted onto a slidable frame member provided inside a frame guide member. A securing member in the form of a releasable screw may be provided in said guide member to secure the slidable member in place (not shown).

The seat elements 60,62 comprise seat members 70,71 which are slidably arranged. The foot supports 63 are mounted onto the seat members 70, 71. The foot supports comprise a first foot support member 75 and a second foot support member 76, the height of the first and second foot support members being slidably adjustable. Locking members 78 are provided to lock the foot support members in a desired position.

The supportive seat is further provided with foot supports 63 and/or other additional supports which provide support. The supports 63 may comprise straps for strapping the feet of the user into place. The seat means can further comprise a strap which fits around the hips of the user, to prevent the user from accidentally falling out of the seat.

The supportive seat 10 further comprises wheels which allow the supportive seat 10 to be conveniently transported. Brakes may be applied on one or more of the wheels to prevent the supportive chair from accidentally moving. The wheels are formed by castor wheels 64. The height adjustment means and tilting means may further be operable by means of an electrical motor or any other alternative means. The supportive seat 10 may further comprise a drive means for driving the seat 10 so that the seat 10 can be used as an electrical powered wheelchair. Finally the handle 64 allows

the seat to be manoeuvred conveniently by an operator and to be tilted and adjusted as shown.

The lateral support 42 comprises a flexible member and covering material. Figure 5 presents a particular embodiment of flexible member 100. The member is connected to the support structure on one end portion 101, and the other end portion 103 is free and shaped as desired. This member 100 comprises a flexible, resilient material such as a plastics material in which recesses 102 are provided which are approximately parallel and equidistant. These recesses give the material its specific flexing properties. The flexible properties or resilience properties of the material can be specifically adapted to the requirements of the user. By increasing the number of recesses 102 the flexible member 100 becomes more flexible and provides less support to the user. A preferred way of applying the slot-like recesses or grooves into the flexible member 100 is by saw cuts or by grinding. This allows these flexible members 100 to be produced efficiently and cost effectively. The flexible member 100 is covered by a suitable covering and/or padding material to increase the comfort to the user.

Finally, Fig. 6 presents an alternative seat 210. The supportive seat 210 comprises a structure 212 for supporting seating means (not shown) and a base 214 for supporting the support structure 212 from the ground. The support structure 212 comprises a first support member 222, a second support member 224 and a third support member 228 similar to the previous Figs. The supportive seat 210 further comprises means 216 for tilting the seat support structure 212 relative to the base 214. The tilting means 216 comprises a pivotal connection member (not shown) which is provided between the first support member 222 and the second support member 224. The tilting means 216 also comprises an extendable member in the form of an electric actuator 226 which is pivotally connected to the respective first and

second support members 222, 224 for tilting the seat means relative to the base 214. The extendable tilting actuator 226 comprises an electric motor for extending and retracting the actuator. The supportive seat 210 further comprises a height adjustment mechanism 218 which comprises a parallel linkage structure 232 which interconnects both the base 214 and the first support member 222. The parallelogram linkage structure 232 consists of two pairs of parallel linkage members 233,234 which are pivotally connected to both a base member 236 and the first support member 222 at respective pivotal connections. An actuator 238 of a similar type as herein before described is applied between the linkage member pair 233,234. The actuator 238 is pivotally connected to the lower linkage member 234 and is also pivotally connected to the base 214. The actuator 238 is similar to actuator 226 and is operated in a similar way as hereinbefore described.

In use, the height of the seat 13, inclination of the seat 13 and position of the third support member (back) of the supportive seat 10 can be adjusted to the requirements of the user. The height and inclination of the seating means 13 are adjusted by operating the respective levers 30,31. Upon operating the lever 30 the seat 13 moves upwards. To move the seat 13 downwards, the lever 30 is again operated and the seat is simultaneously pushed downwards. To tilt the seat forwards, the lever 31 is operated and the seat 13 tilts forwards. To move the seat 13 to its original inclination, the lever 31 is operated and the seat 13 is simultaneously tilted backwards. The inclination of the third support member is adapted by releasing the first securing means and tilting the third support member to the desired position and subsequently securing the first securing means.

The lateral supports 40,42, 44 can be adjusted to the user's requirements by releasing the lateral securing means,

operating the lateral positioning means 46 and fixing the lateral securing means. Additional adjustments can be made to the seat elements on the second support member and other supports as hereinbefore described.

Finally, the supportive seat 10 can be conveniently pushed to a required position by an operator using the handle. This handle is also convenient for tilting the seat 13 and adjusting the height of the seat 13.

The supportive seat 210 is adjustable in a similar way to the seat 10. The difference between seat 210 and seat 10 is that the tilting and height adjustment are electrically controlled.

Amongst other modifications which could be made in thE above embodiments are: a supportive seat comprising a highadjustment means, a supportive seat comprising a tilting mechanism, a supportive seat comprising one or more lateral supports, a supportive seat comprising a first positioning means, a supportive seat comprising one or more extendable seat elements, and/or combinations of the aforesaid modifications.

Claims (39)

1. A supportive seat comprising means for seating a user, a structure for supporting said seating means and a base for supporting said support structure from the ground.

2. Supportive seat according to claim 1, wherein the support structure comprises a first support member and one or more further support members.

3. Supportive seat according to claim 2, wherein the supportive seat comprises means for tilting the seating means relative to the base.

4. Supportive seat according to claim 3, wherein said first support member and said further support members are pivotally interconnected and the tilting means comprise a first extension means for providing an extendable connection between said first support member and said further support member in such a way that the further support member is tiltable relative to the first support member upon extension or retraction of said first extension means.

5. Supportive seat according to claim 4, wherein the first extension means is pivotally connected to both said first support member and the further support member.

6. Supportive seat according to claim 5, wherein the first extension means comprises one or more extension members in the form of an extendable element such as a cylinder, said cylinder comprising hydraulics and/or pneumatics and/or spring activating means or

combinations thereof, or an electrically operated extension.

7. Supportive seat according to any of claims 2 to 6, wherein the supportive seat comprises means for adjusting the height of the seat support structure relative to the base.

8-Supportive seat according to claim 7, wherein the height adjustment means comprises a linkage structure which interconnects said support structure and said base, said height adjustment means further comprising a second extension means for moving said support structure relative to the base.

9. Supportive seat according to claim 8, wherein the base comprises a base member and the linkage structure comprises one or more first linkage members and one or more second linkage members, each respective linkage member being pivotally connected to said base memler and to said first support member such that a

parallelogram linkage structure is formed.

10. Supportive seat according to claim 8 or 9, wherein said second extension means is pivotally connected to the base and the first linkage member approximately equidistant from the respective pivotal connections of said first linkage member on said base member and on said first support member.

11. Supportive seat according to claim 8 or 9, wherein the second extension means is pivotally connected to the base and the first support member.

12. Supportive seat according to any of claim 8 to 11,

wherein said extension means comprises one or more extension members in the form of an extendable element such as a cylinder, said cylinder comprising hydraulics and/or pneumatics and/or spring activating means or combinations thereof or an electrically operated extension.

13. Supportive seat according to any of claims 2 to 12, wherein the support structure is provided with additional user support elements in the form of foot supports and/or knee supports and/or leg supports.

14. Supportive seat according to claim 13, wherein said additional user support members comprise further positioning means for positioning said additional user support members in a desired position relative to the user.

15. Supportive seat according to claim 2 to 14, wherein the seating means comprises one or more seat elements and the further support members comprise a second support member and a third support member for supporting said seat elements.

16. Supportive seat according to claim 15, wherein said seat elements are removably mounted onto the support structure.

17. Supportive seat according to claim 15 or 16, wherein said second and third support member are pivotally interconnected, said seat structure further comprising one or more first positioning means for positioning said third support member relative to said second support member.

18. Supportive seat according to claim 17, wherein said first positioning means comprises a first guide member and a first member being slidably arranged inside said first guide member, said first slidable member being pivotally connected to said support member, said first guide member being pivotally connected to another support member, said first positioning means further comprising first securing means for securing said first slidable member in a desired position.

19. Supportive seat according to claim 18, wherein the first guide member comprises a first recess and said first securing means comprises one or more clamp members, said clamp members being engagable with at least part of the first slidable member in at least part of said first recess, said first positioning means further comprising activating means for engaging and releasing said clamp members.

20. Supportive seat according to claim 19, wherein said first securing means comprises a further guide member ; said further guide member comprising a further recess, said further guide member being mounted onto said first guide member approximately perpendicular thereto such that said further recess corresponds with said first recess, said clamp members being slidably arranged inside said further guide member.

21. Supportive seat according to claim 19 or 20, wherein the activating means comprises an operating member which is operable by rotation to alternatively release or engage the clamping means.

22. Supportive seat according to any of claims 15 to 21, wherein said second support member comprises one or

more second positioning means for positioning the seat elements in a desired position, said second positioning means comprising a frame member and at least one support element for supporting a seat element, said support element being slidably arranged relative to the frame member.

23. Supportive seat according to claim 22, wherein said frame member comprises one or more second guide members, said seat support element comprising one or more second slidable members, said second slidable members being slidably arranged in said second guide members for positioning said seat elements in a desired position.

24. Supportive seat according to any of claims 15 to 23, wherein the third support member comprises third positioning means for positioning the seat elements in the desired position relative to the user.

25. Supportive seat according to any of claims 15 to 24, wherein one or more seat elements comprise a foot support and/or knee support and/or leg support.

26. Supportive seat according to claim 25, wherein the seat elements are individually positionable to provide support to the user.

27. Supportive seat according to any of claims 15 to 26, wherein the third support member comprises one or more lateral supports.

28. Supportive seat according to claim 27, wherein each lateral support comprises lateral positioning means for positioning said lateral supports in a direction

approximately parallel to the third support member and approximately perpendicular thereto.

29. Supportive seat according to claim 27 or 28, wherein the lateral support comprises a flexible member, said flexible member comprising a sheeted flexible material, the sheeted flexible material comprising a plurality of linear recesses or grooves substantially parallel to one another for reducing the stiffness of the flexible member.

30. Supportive seat according to any of claims 27 to 29, wherein the lateral support comprises a padding material and/or a cover material.

31. Supportive seat according to any of the preceding claims wherein the base comprises one or more transport means in the form of wheels and/or castor wheels.

32. Body support element comprising a sheeted flexible material, the sheeted flexible material comprising a plurality of linear recesses substantially parallel to one another.

33. Body support element comprising a flexible sheeted material, the material comprising a degree of inherent stiffness adequate for support a body, the material further comprising one or more recesses or slots generally in line with each other parallel to an axis along which bending is to occur so as to conform to the body under modest loads.

34. Body support element according to claim 32 or 33, wherein the body support comprises a padding material and/or a cover material.

35. A supportive seat according to any of claims 1 to 31, comprising one or more body support elements according to any of claims 32 to 34.

36. Positioning means for positioning a first member relative to a second member, the respective members being pivotally interconnected, said positioning means comprising a first guide member and a first slidable member being slidably arranged inside said first guide member, said first slidable member being pivotally connected to said first member, said first guide member being pivotally connected to said second member, said first positioning means further comprising securing means for securing said first slidable member in a desired position.

37. Positioning means according to claim 34, wherein the first guide member comprises a recess and said securing means comprises one or more clamp members, said clamp members being engagable with at least part of the first slidable member in at least part of said recess, said first positioning means further comprising activating means for engaging and releasing said clamp members.

38. Positioning means according to claim 35, wherein said securing means comprises a further guide member, said further guide member comprising a further recess, said further guide member being mounted onto said first guide member approximately perpendicular thereto such that said further recess corresponds with said recess, said clamp members being slidably arranged inside said further guide member.

39. Wheelchair comprising an supportive seat according to any of claims 1 to 31.