GB2307213A

GB2307213A - Transfer system for persons

Info

Publication number: GB2307213A
Application number: GB9523664A
Authority: GB
Inventors: Robert Hester
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-11-18
Filing date: 1995-11-18
Publication date: 1997-05-21
Also published as: GB9523664D0

Abstract

A transfer system for use on a wheelchair, a dentist's chair, an operating table, a vehicle or the like 17 comprises a seat and an arm 15 connecting the seat and the wheelchair or the like, at least one end of the arm having pivoting about a vertical axis. Both ends of the arm may pivot about a vertical axis. A further arm (19 figure 2) may connect the seat and the wheelchair or the like. The seat may be locked in at least one position. The seat may comprise a base 1, a back 3 and a front 5 pivotally connected to one another and to a support assembly 9, the back and front being linked by at least one tie rod 7 to form a parallelogram linkage to allow the seat to raise a person to an upright position or to lower them to a prone position (figure 5). The seat may be biassed by means 11 into a seated configuration (figure 1).

Description

TRANSFER SYSTEM FOR INVALIDS, PATIENTS OR THE LIKE The present invention is concerned with a transfer system for invalids, patients, disabled persons or the like. The transfer system may be employed, for example, in wheel chairs, dental chairs, operating tables or vehicles.

In known wheel chairs, the seat of the chair is generally mounted securely to the remainder of the chair. However, in order to provide greater independence to the user of the chair it is desirable in certain situations for the seat to be movable relative to the remainder of the wheelchair.

For example, if the seat is pivotable relative to the remainder of the chair, the user can then sit alongside the remainder of the chair to give an impression of having a degree of independence from the chair, or, particularly in the case of a motorised wheel chair, the user can pivot the seat in order to position the seat over a toilet or the like so as to use the seat as a commode. A transfer system for moving a seat in this manner relative to some other object can also be used in relation to dental chairs or operating tables, or in respect of vehicles to permit a disabled person more ready access to a vehicle.

It is therefore an object of the present invention to provide a transfer system for invalids, patients, disabled persons or the like in which a seat is pivotable laterally with respect to a structure on which the seat is mounted.

According to the present invention there is provided a transfer system for a wheel chair or the like comprising seat receiving means mounted so as to be pivotal about an upright axis at one end of an arm, the arm being mounted so as to be pivotal about an upright axis at the other end thereof.

The transfer system may include a further arm pivotably mounted about an upright axis on the seat receiving means and mounted so as to be pivotal about an upright axis at the other end thereof, the arm and the further arm acting in combination to control the orientation of the seat receiving means during pivoting of the first-mentioned arm.

The further arm may be in the form of a crank arm. The further arm may extend generally parallel to the firstmentioned arm.

The transfer system may include means for locking the seat receiving means in at least one position.

The seat receiving means may comprise a framework comprising a base assembly, a back assembly and a front assembly, one of the back assembly and the front assembly being pivotably mounted in the region of one end thereof on the base assembly and the other of the back assembly and the front assembly being pivotably mounted intermediate the ends thereof on the base assembly, the back assembly and the front assembly being pivotably mounted on the base assembly so as to be pivotable about parallel axes and at least one tie rod extending between the front assembly and the back assembly and pivotably secured to each thereof to as to form a parallelogram arrangement. The framework may be mounted on the arm in a manner which permits pivoting about a generally horizontal axis. The framework may be mounted on the arm by way of the base assembly or by way of the at least one tie rod.

Biasing means may be provided so as to bias the front assembly in a direction towards the back assembly and in a generally upward direction so as to bias the parallelogram arrangement into the configuration of a seat. Stop means may be provided to prevent that part adjacent the back assembly falling to a level below that part of the base assembly adjacent the front assembly.

Actuator means may be provided so as to raise and/or lower the front assembly.

If the actuator means should lower the front assembly, that part of the base assembly in the region of the front assembly will be moved downwardly about the horizontal axis and that part of the base assembly in the region of the back assembly will be moved upwardly about the horizontal axis, with the parallelogram arrangement maintaining the front assembly and the rear assembly in a substantially upright configuration. The effect of this is to transfer a person sitting on the seat receiving means from a sitting position substantially to an upright position.

If the actuator means should raise the front assembly, the stop means will prevent pivoting of the base assembly and the free end of the front assembly will be pivoted upwardly with the parallelogram arrangement correspondingly pivoting the free end of the back assembly downwardly. The effect of this is to transfer a person sitting on the seat receiving means from a sitting position substantially to a lying position.

Thus a single actuator means can be used to both raise a person from a sitting position to an upright position and back and to lower a person from a sitting position substantially to a lying position and back.

The actuator means may be employed to lock the seat receiving means in the at least one position. For example, the actuator means may be operated in the at least one position to raise the front assembly at least partly so as to release locking means and may subsequently be operated in the at least one position so as to engage locking means.

Means may be provided to lock the parallelogram arrangement in at least one position, for example the sitting position.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a diagrammatic side elevational view of one embodiment of a framework of a transfer system according to the present invention; Figure 2 is a plan view of the framework shown in Figure 1 in a first position; Figure 3 is a plan view of the framework shown in Figure 1 in a second position; Figure 4 is a diagrammatic side elevational view of the framework of Figures 1 to 3 in an upright extended position; and Figure 5 is a diagrammatic side elevational view of the framework of Figures 1 to 3 in a generally horizontal extended position.

The transfer system according to the invention can be constructed around a seat receiving means in the form of the framework shown in Figures 1 to 3. The framework can be provided with a seat, backrest, headrest, armrests, footrest or the like in a manner which is clear to the skilled person.

The framework comprises a generally horizontal base assembly 1, for example in the form of a base plate on which a user will sit. A cushion (not shown) will be provided on the base plate for normal use, but the base plate will generally be provided with an aperture adapting the plate for use as a commode when desired.

One side of the base assembly 1 (the rear of the base assembly in use) has pivotably mounted thereon one end of an upright back assembly 3, for example in the form of a back plate. In use, a cushion (not shown) will be provided on the back assembly 3 and a head rest (not shown) may be provided at the free end thereof.

The opposite side of the base assembly 1 (the front of the base assembly in use) has pivotably mounted thereon an upright front assembly 5, for example in the form of a front plate. It will be noted that the front assembly is pivotably mounted along an axis spaced from the upper and lower ends thereof for reasons that will be explained in more detail hereinafter. The lower end of the front assembly 5 may be provided with a footplate (not shown) or a foot rest (not shown).

Pivotably mounted to opposite lateral sides of the front assembly is one end of each of two tie rods 7. The opposite end of each tie rod 7 is pivotably mounted at opposite sides of the back assembly 3. The distance between the upper end of the front assembly 5 and the axis about which the front assembly is pivotable corresponds substantially to the distance between the point at which the tie rods 7 are pivotably mounted on the back assembly 3 and the axis about which the back assembly is pivotable, thus resulting in a parallelogram arrangement.

The base assembly 1 is pivotably mounted about a generally horizontal axis to an upright support assembly 9, the pivot axis being spaced further from the back assembly than from the front assembly in order to avoid interfering with any aperture provided in the base assembly 1 for use as a commode and for reasons that will be explained in more detail hereinafter.

Resilient biasing means 11, such as an elastomeric material or a coil spring, extends between the support assembly 9 and the front assembly 5 so as to bias the free (lower) end of the front assembly in a direction towards the support assembly 9. In practice, the resilient biasing means is secured to an upper region of the support assembly 9. The effect of the resilient biasing means 11 is to bias the lower end of the front assembly towards the support assembly and upwardly relative thereto and thus to bias downwardly that end of the base assembly 1 which is pivotally connected to the back assembly 3. In practice, the base assembly 1 bears against stop means (not shown) to limit the downward movement of the back assembly 3 and to maintain the base assembly substantially horizontal in order to provide a comfortable seat for the user.

Also mounted between the front assembly 5 and the support assembly 9 is an actuator 13. The actuator may comprise, for example, a linear actuator operated by an electric motor, an hydraulic actuator or a pneumatic actuator. As can be seen from Figures 1 to 3, the actuator extends between the upper region of the front assembly and the lower region of the support assembly. The actuator 13 can be extended or contracted to alter the relative orientations of the base assembly, the back assembly and the front assembly in a manner that will be described in more detail hereinafter.

The support assembly 9 is mounted for pivoting about an upright axis at the free end of a pivot arm 15 which is itself mounted for pivoting about an upright axis relative to a fixed mounting 17. As can be seen from Figures 2 and 3, relative pivoting movement between the base assembly 1 and the fixed mounting 17 is determined by a further arm in the form of a crank arm 19 which is pivotably mounted on the fixed mounting and on the support assembly. The effect of the crank arm 19 is that as the pivot arm 15 is rotated in a counter-clockwise direction the seat assembly is also rotated in a clockwise direction to a limited degree. The effect of the crank arm 19 is to control relative rotation between the base assembly 1 and the fixed mounting 17 in order that the user can manually pivot the base assembly.

Clearly, the configuration of the crank arm 19 and the manner in which it is mounted relative to the pivot arm 15 can be varied so as to control the manner in which the base assembly pivots in response to pivoting of the pivot arm.

As an alternative to manual control of pivoting, means may be provided to control pivoting of the base assembly. Such pivoting means may comprise, for example, an actuator for extending or contracting the length of the crank arm 19 or means for independently pivoting, within predetermined limits, the pivot arm 15 relative to the fixed mounting and the base assembly relative to the pivot arm. The pivoting means may comprise, for example, an electric motor or hydraulic or pneumatic means. Thus, the pivot arm, when operated, is able to move the base assembly between a first position in which, for example, the base assembly is located on a base of a wheel chair (not shown) and a second position in which the base assembly is located in a position beside the base of the wheel chair but rotated by a predetermined amount so as to partly face the wheel chair.

It will generally be essential to be able to lock the base assembly in at least one of the first and second positions.

For example, in the case of a fixed mounting in the form of the base of a wheel chair, it will be essential to be able to lock the base assembly in the first position for a number of reasons. One reason is the need to maintain the base assembly in position on the wheel chair when the wheel chair is being manoeuvred, another reason is that the user may wish to drive a motor vehicle, in which case it is essential for safety reasons that the base assembly is secured in the first position relative to the base of the wheel chair. Any suitable form of locking means may be used, such as a locking pin (not shown) engageable between the base assembly and the base of the wheel chair.

Alternatively, at least one locking pin (not shown) may be provided on the base of the wheel chair, or preferably on the base assembly, to engage with the other component as the base assembly is lowered onto the base of the wheel chair, for example in a manner as will be explained in more detail hereinafter in relation to Figures 4 and 5.

The framework can be incorporated, by way of the fixed mounting, into a wide variety of structures which are not shown in the drawings. The primary application is intended to be an electrically powered motorised wheel chair, but the framework can readily be incorporated into a dentist's chair, an operating table or even a vehicle.

Figure 4 shows how the base assembly can be inclined while the front assembly is lowered and the back assembly is raised in order to raise a user substantially to a standing position. This operation is effected by contracting the actuator 13 which causes the base assembly 1 to pivot about is mounting on the support assembly 9. The parallelogram linkage formed by the base assembly 1, the front assembly 5, the back assembly 3 and the tie rods 7, controls the relative orientation of the front assembly and the back assembly in order to support the legs and back of the user and to bring the user to a standing position.

Figure 5 shows how the front assembly and the back assembly can be inclined while the base assembly maintained in a generally horizontal position in order to lower a user substantially to a lying position. This operation is effected by extending the actuator 13 which causes the front assembly 3 to pivot about is mounting on the base assembly 1, the base assembly being prevented from pivoting any further downwardly at the rear end thereof by the stop means (not shown). The parallelogram linkage formed by the base assembly 1, the front assembly 5, the back assembly 3 and the tie rods 7, controls the relative orientation of the front assembly and the back assembly in order to support the legs and back of the user and to bring the user to a lying position.

The ability to transfer a user between a standing position, a sitting position and a lying position is particularly important in the case of a severely disabled user in order to change the way in which the user's body weight is supported. The use of a parallelogram linkage ensures that movement of the front assembly and of the back assembly is coordinated and that there is no risk of injuring the user when transferring the user between the various positions.

The resilient biasing means 11 biases the front assembly into a position in which it is urged to an upright position and in which the front assembly is biased upwardly. The effect of this, through the parallelogram linkage, is to return the user to a sitting position when the actuator is released from its extended or its contracted configuration.

The manner in which the parallelogram linkage operates depends upon the relative lengths of the arms of the linkage, the distance between the pivot axis of the base assembly and the axis about which the front assembly is pivotable, and the points at which the actuator is mounted on the front assembly and the support assembly. Once the components have been selected, the required dimensions and positions can be determined by simple experimentation and require no inventive activity.

It may be desirable or necessary to be able to lock the base assembly and the back assembly in position relative to each other, particularly in the sitting position of the user. Indeed, should the user may wish to drive a motor vehicle it is essential for safety reasons that the back assembly can be locked in position relative to the base assembly. Any suitable form of locking means may be used and the locking means may be effective to lock the back assembly relative to the base assembly or to lock one or more of the tie bars relative to the base assembly.

Movement between an upright position of the user, or at least a position intermediate a sitting position and an upright position, can be combined with pivoting movement of the base assembly relative to the fixed mounting in order to lock and unlock the base assembly in position relative to the fixed mounting, such as the base of a wheel chair.

In this respect, the base assembly may be provided with one or more locking pins which are receivable in corresponding recesses provided in the base of a wheel chair when the user is in a sitting position. The actuator can then be operated to extend the same and to raise the user to, or towards, an upright position by raising the rear end of the base assembly. In so doing, the or each locking pin is raised and released from its associated recess. The base assembly can then be pivoted relative to the base of the wheel chair and the actuator released to return the user to a sitting position. Returning the base assembly to its position on the base of the wheel chair is a reverse of this procedure and lowering the base assembly onto the base of the wheel chair automatically causes the or each locking pin to engage with the associated recess thus locking the base assembly against undesired pivoting relative to the base of the wheel chair.

The user of the wheel chair or the like can be provided with controls in various forms adaptable to the user in order to control the attitude of the framework and, if desired, the pivoting of the framework relative to the fixed mounting.

Claims

1. A transfer system for a wheel chair or the like comprising seat receiving means and an arm interconnecting the seat receiving means and the wheelchair or the like, the arm being interconnected to the seat receiving means and/or the wheelchair or the like at least at one end thereof by way a pivotal mount having an upright axis.

2. A transfer system as claimed in claim 1, wherein the seat receiving means is mounted so as to be pivotal about an upright axis at one end of an arm and the arm is mounted so as to be pivotal about an upright axis at the other end thereof.

3. A transfer system as claimed in claim 1 or 2 and including a further arm pivotably mounted about an upright axis on the seat receiving means and mounted so as to be pivotal about an upright axis at the other end thereof, the arm and the further arm acting in combination to control the orientation of the seat receiving means during pivoting of the first-mentioned arm.

4. A transfer system as claimed in claim 3, wherein the further arm is in the form of a crank arm.

5. A transfer system as claimed in claim 3 or 4, wherein the further arm extends generally parallel to the firstmentioned arm.

6. A transfer system as claimed in any preceding claim and including means for locking the seat receiving means in at least one position.

7. A transfer system as claimed in any preceding claim, wherein the seat receiving means comprises a framework comprising a base assembly, a back assembly and a front assembly, one of the back assembly and the front assembly being pivotably mounted in the region of one end thereof on the base assembly and the other of the back assembly and the front assembly being pivotably mounted intermediate the ends thereof on the base assembly, the back assembly and the front assembly being pivotably mounted on the base assembly so as to be pivotable about parallel axes and at least one tie rod extending between the front assembly and the back assembly and pivotably secured to each thereof to as to form a parallelogram arrangement.

8. A transfer system as claimed in claim 7, wherein the framework is mounted on the arm in a manner which permits pivoting about a generally horizontal axis.

9. A transfer system as claimed in claim 7 or 8, wherein the framework is mounted on the arm by way of the base assembly or by way of the at least one tie rod.

10. A transfer system as claimed in claim 7, 8 or 9, wherein biasing means is provided so as to bias the front assembly in a direction towards the back assembly and in a generally upward direction so as to bias the parallelogram arrangement into the configuration of a seat.

11. A transfer system as claimed in claim 10, wherein stop means is provided to prevent that part adjacent the back assembly falling to a level below that part of the base assembly adjacent the front assembly.

12. A transfer system as claimed in any one of claims 7 to 11, wherein actuator means is provided so as to raise and/or lower the front assembly.

13. A transfer system as claimed in claim 12, wherein, if the actuator means should lower the front assembly, that part of the base assembly in the region of the front assembly is moved downwardly about the horizontal axis and that part of the base assembly in the region of the back assembly is moved upwardly about the horizontal axis, with the parallelogram arrangement maintaining the front assembly and the rear assembly in a substantially upright configuration.

14. A transfer assembly as claimed in claim 12 or 13, wherein, if the actuator means should raise the front assembly, the stop means prevents pivoting of the base assembly and the free end of the front assembly is pivoted upwardly with the parallelogram arrangement correspondingly pivoting the free end of the back assembly downwardly.

15. A transfer assembly as claimed in claim 12, 13 or 14, wherein the actuator means is employed to lock the seat receiving means in the at least one position.

16. A transfer assembly as claimed in claim 15, wherein the actuator means is operated in the at least one position to raise the front assembly at least partly so as to release locking means and is subsequently operated in the at least one position so as to engage locking means.

17. A transfer assembly as claimed in any one of claims 7 to 16, wherein means is provided to lock the parallelogram arrangement in at least one position, for example the sitting position.