GB2234491A

GB2234491A - Bath lift

Info

Publication number: GB2234491A
Application number: GB9016385A
Authority: GB
Inventors: John Alfred Hooker; Christopher John Hooker
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-05
Filing date: 1990-07-26
Publication date: 1991-02-06
Anticipated expiration: 2010-07-26
Also published as: GB9016385D0; GB2234491B

Abstract

A bath aid unit comprises a seat (19) supported by a pivoted scissors-type frame structure adapted to rest on a bath bottom. The seat (19) is displaceable between raised and lowered positions by an electrical power actuating unit comprising an electric motor (7) and a reduction gearbox (16) to rotate an internally threaded shaft portion (4) on a screw shaft (5) whereby the shaft portion (4) can move up and down along the shaft (5). The actuating unit includes a water- resistant gaiter (14) on the shaft (5), phosphor bronze bearing members (3, 9) supporting the shaft portion (4) to resist the ingress of water, and an enclosing tube (10) to contain water and prevent it from reaching the motor (7), thus providing a multiple sealing effect for the actuating unit. The actuating unit includes an emergency manual actuating arrangement comprising a crank (17, 18) for actuation of the bath unit upon failure of the actuating unit. <IMAGE>

Description

Electrically powered bath aid unit The present invention relates to an electrically powered bath aid unit which for example is intended to enable in particular disabled or elderly people to bathe more easily.

Disabled and elderly people may often encounter considerable difficulty in taking a bath, more especially from the point of view of having to climb into and out of the bath. Such difficulties frequently require the assistance of another person, and that may not be readily available, or mean that the person wishing to take a bath may only do so at the cost of severe physical exertion, which may be beyond them.

According to the present invention there is provided a bath aid unit comprising a seat member on which a user can sit, a support frame structure connected to the seat member and arranged to rest on the bottom of the bath, the support frame structure being displaceable between a first position in which the seat member is raised from the bottom of the bath and a second position in which the seat member is lowered at least substantially to the bottom of the bath, a power actuating unit comprising an electric motor and a gearbox and operable to produce displacement of said seat member to provide for said raising and lowering movement thereof, and a plurality of means performing a water-resistant sealing effect to seal at least the motor and the gearbox relative to the exterior of the power actuating unit.

In a preferred feature of the invention, the support frame structure comprises first and second leg assemblies disposed in crossed scissor-like relationship with the leg assemblies pivoted together at their crossing point, the upper ends of the first and second leg assemblies being connected to said seat member for said raising and lowering movement thereof, and wherein said power actuating unit comprises a screw shaft connected to a portion of one of said leg assemblies and an electric motor-gearbox assembly connected to a portion forming part of or operatively associated with the other said leg assembly or said seat member, said gearbox of said electric motorgearbox assembly including drive means co-operating with said screw shaft for said raising and lowering movement of said seat member.

In a further preferred feature of the invention, the bath aid unit includes an alternative means of operating the power actuating unit manually for said raising or lowering movement of said seat member, for example in the event of failure of said power actuating unit. That configuration provides for the eventuality that, as only low voltage equipment is generally permitted in a bathroom, the electric motor of the power actuating unit may be for example a 12 volt motor fed by a 12 volt battery which must be maintained in a fully charged condition; if however the user of the unit neglects the battery charging requirement the motor may have insufficient power to raise the seat member and allow the user to leave the bth.In that situation therefore the alternative means for operating the unit manually may be used while the gearbox and electric motor are below the level of water in the bath, without allowing water to come into contact with either the electrical or gearbox components of the unit.

An embodiment of a bath aid unit according to the present invention will now be described by way of example with reference to the accompanying drawing in which the single Figure is a diagrammatic side view partly in section of the bath aid unit in a raised position.

Referring now to the drawing, the bath aid unit shown therein comprises a seat member 19 on a support frame structure formed by first and second leg assemblies which are disposed in mutually crossed relationship, being plvoted together by suitable pivots (not shown) at their locations at which they cross, thereby to provide a scissor-like configuration. The respective leg assemblies are connected at their upper ends to the seat member 19, with one of the leg assemblies, at the right in the drawing, being pivotally connected to the seat member 19 while the other leg assembly, at the left, is connected thereto slidably in a fore-and-aft direction relative to the seat member 19, the sliding connection being required to permit scissor-like extension and retraction of the support frame structure.In that way the seat member 19 can be displaced between a first position in which it is raised from the bottom of a bath in which the bath aid unit is disposed, and a second position in which the seat member is lowered at least substantially to the bottom of the bath.

It will be appreciated that the leg assemblies have suitable buffer members or caps, or rollers or wheels, at the lower ends of the respective leg assemblies, to permit appropriate movement of the support frame structure without damaging the surface of the bath and to provide a non-slip support for the unit on the bottom of the bath.

The illustrated unit further includes a water-resistant or waterproof casing 1 which is preferably in the form of a tube portion closed at each of its top and bottom ends by respective end closures as indicated at 2, for example in the form of aluminium castings. The tube portion may comprise any suitable material such as a metal or plastics material. The bottom end closure 3 has an opening therethrough to accommodate a plain bearing member 3 for example of phosphor bronze, which is suitably mounted therein. Rotatably disposed in the bearing member 3 is a hollow shaft portion 4 having a female screwthread extending through the bore thereof.Reference numeral 5 identifies a drive shaft or spindle having a male screwthread extending over at least a substantial part thereof, the upper end portion of the shaft 5 extending into the snaft portion 4, with the screwthread onthe shaft 5 being engaged with the female screwthread in the shaft portion 4.

Reference numeral 6 identifies a drive gear which is fixed with respect to the shaft portion 4, being for example integral therewith or alternatively secured thereto in any suitable fashion. Rotation of the drive gear 6 causes rotary movement of the shaft portion 4 which will thus screw itself up or down along the drive shaft 5, depending on the direction of rotation of the drive gear 6 and the shaft portion 4.

Also disposed within the casing 1 is a suitable electric motor 7 such as a 12 volt dc motor carried upon a supporting plate 8 in the interior of the casing 1. The support plate 8 is disposed in the casing 1 in such a way as to provide a water-resistant partitioning effect therein, dividing the casing 1 into an upper space as indicated by reference numeral 12, which can thus be identified as a motor compartment, above the support plate 8, and a lower space identified by reference numeral 16, below the support plate 8, to provide a gearbox compartmetit. The gear assembly therein will be described below.

The support plate 8 has an opening therethrough to accommodate a plain bearing member 9 for example of phosphor bronze, for rotatably supporting the upper end of the shaft portion 4. The shaft portion 4 is an at least water-resistant fit in the bearing members 3 and 9. A tube 10 has its lower end disposed around the upwardly extending end portion of the bearing member 9, and extends upwardly within the casing 1 to the upper end closure 2 thereof. The tube 10 is sealingly joined to the support plate 8 and/or the plain bearing member 9 at its lower end, and the upper end closure 2 of the casing 1. For that purpose the upper end portion of the tube 10 fits over a downwardly projecting spigot 11 on the underside of the upper end closure 2. The space within the tube member 10 is thus sealed off from the remainder of the interior of the motor compartment 12.The spigot 11 has a hole extending therethrough, forming a communication between the outside air and the interior of the tube 10. Reference numeral 13 identifies a removable plug which can be fitted into the hole in the spigot 11 to close off the upper end of the space within the tube 10.

Reference numeral 14 indicates a flexible concertina-like gaiter or bellows member of any suitable material such as plastics material, for example PVC, having an upper end which is suitably secured to the bottom end closure 2 of the casing 1 or to a downwardly extending end portion of the plain bearing member 3, for example by a clamping ring, while the lower end of the gaiter 14 is secured to the lower end portion of the shaft 5. The gaiter 14 thus provides an at least waterresistant containment for the shaft 5 as it moves into and out of the casing 1 upon upward and downward movement of the seat member 19.

The upper end face of the shaft portion 4 has an engagement means such as a suitably shaped recess or groove therein and a tubular operating member or shaft 17 with corresponding engagement means at the lower end can be inserted into the tube 10, after removal of the plug 13, and pushed downwardly therein so that the engagement means on the end of the member 17 engage into the engagement means on the upper end of the shaft portion 4. The lower end of the member 17 fits over the upwardly extending end portion of the shaft 5, where it projects from the bearing member 9. The member 17 carries a handle as indicated at 18, for manual actuation of the arrangement.Thus, by turning the handle 18, the member 17 can be rotated within the enclosing tube 10 to produce suitable rotary motion of the shaft portion 4 and cause the shaft portion 4 to move up or down along the shaft 5, depending on the direction of rotation of the handle 18. As the shaft portion 4ncves fnrewrpledown the shaft 5, the upper end portion of the shaft 5 will move upwardly within the interior of the member 17, until the seat member 19 has been moved into its lowered position in which it is disposed substantially at the bottom of the bath in which the bath aid unit is disposed.Thus, in the event of a failure of the electrical power unit, for example due to a battery for operating the electric motor 7 failing or being insufficiently charged, the bath aid unit can be operated manually by turning the handle 18 so that the seat member 19 can be raised by a helper to avoid the person using the unit being trapped in the bath.

The electric motor 7 has an output shaft which projects downwardly through the support plate 8 into the gearbox compartment 16, where it carries a suitable drive gear (not referenced). The drive gear in turn meshes with a gear assembly comprising a first gear portion of substantial diameter and a second gear portion which is integral therewith or fixed with respect thereto, of substantially smaller diameter, thereby providing a step-down effect between the drive gear on the shaft of the electric motor and the second gear portion of the gear assembly. The second gear portion of the gear assembly meshes with the drive gear 6 on the hollow shaft 4. Actuation of the electric motor 7 will result in rotation of the drive gear 6 through the reduction gearbox referred to above.

As indicated above the relationship between the shaft portion 4 and the bearing members 3 and 9 is such as substantially to resist the ingress of water into the gearbox compartment 16.

The power actuating unit described above is suitably connected to the other structure of the bath aid unit, for example by the casing 1 being fixed to the seat member 19 or to a part of one of the leg assemblies of the unit. As the power actuating unit is operated, the seat member 19 will be suitably displaced, between its raised and lowered positions.

It will be seen from the foregoing description that the electric motor 7 and the gearbox driven thereby are enclosed within the at least water-resistant casing 1. The exposed part of the shaft 5 which extends downwardly out of the casing 1 is enclosed by the gaiter or bellows member 14. If the gaiter 14 should develop a leak after constant use and perhaps abuse, water may penetrate thereinto and in turn penetrate between the threads on the shaft 5 and the shaft portion 4. However the water will not be able to penetrate further into the gearbox compartment 16 because the shaft portion 4 rotates in the bearing members 3 and 9 with a close fit, so that water will be unable to penetrate between the bearing members 3 and 9 and the shaft portion 4.

Even if water continues to penetrate along the threads of the shaft portion 4 and the shaft 5 upwardly towards the motor compartment 12, that water will be contained within the tube 10 by virtue of the sealing integrity thereof in relation to the remainder of the interior of the motor compartment 12. In order to provide a further waterproofing effect, the electric motor 7 can also be of a water-resistant sealed type.

To power the unit, a suitable battery may be contained within for example a box of plastics material of such a configuration as to hang on the outside of the bath, with the box having a suitable switch for operation of the unit. For example the lid of the box may involve a 'see-saw' action to operate the control switch for producing the upward and downward movements of the seat member 19.

The control arrangement may also include suitable safety devices such as a device to ensure that the unit does not suffer damage if the user should try to actuate the unit for upward movement of the seat member 19 when the seat member 19 is already at its most upward position, or downward movement of the seat member when the seat member is already at its lowermost position. Furthermore, the control box may also include battery condition warning lights, for example green for satisfactory charge and red to indicate that the battery requires charging. It is desirable that, when a test button is pressed to check the battery, the seat should not move as a result of actuation of the button because the seat member will then be in less than the best position.

The control box therefore includes a control circuit on a printed circuit board, co-operating with first and second reed switches mounted in appropriate positions on the vertical tube 10 and a magnet mounted on the shaft 5 to activate the reed switches in operation of the seat unit. The circuitry involved permits all necessary functions of the unit to be effected by the operation of a single button, and it further provides for preprograming of the seat member to travel in the correct direction, for example if the seat member is in its raised position, the next travel direction thereof is down and vice-versa if the seat member is in its lowered position. Furthermore if the seat member is stopped part of the way through its travel movement by virtue of the operating button being released, the circuitry will remember the direction of travel of the seat member so that it will continue to move in the same direction when the button is pressed again. The control circuitry will also automatically switch off the drive motor at the upper and lower limits of movement of the seat member 19 and at that position will reprogram the motor to operate in the opposite direction of travel of the seat member 19 when the motor is switched on again by the operating button being pressed.The control circuitry will provide a delay for example of approximately 10 seconds between the operating button being pressed and the electric motor coming into operation, in order to obviate the above-described situation in which pressing of the button to check the battery charge state could otherwise result in movement of the seat member. While the circuitry will register the battery charge condition and indicate same by lighting for example a green light or a red light, the circuitry will also register on the red light when there is sufficient reserve of power left in the battery, so that the user of the unit cannot take a bath when the battery is about to fail.

It will be noted that when the seat member 19 is positioned in its lowered position in the bath, the top of the casing 1 will generally be above the level of the water in the bath. If however the bath aid unit is employed in especially deep water so that the casing 1 is completely immersed, water in the bath would still be unable to penetrate beyond the tube member 10 and the manual actuating arrangement with the handle 18 could still be used.

It will be appreciated that the above-described construction has been set forth by way of example and illustration and that various other modifications and alterations may be made therein without departing from the scope of the invention as defined by the appended claims. For example it would be possible to provide suitable seals operatively associated with the bearing members 3 and 9 to enhance the water-sealing action at those locations. The unit may also include a one-way valve on or operatively associated with the gaiter 14 at any suitable position to allow air to issue therefrom, without however allowing a flow of air or water into the assembly. A further one-way valve may be provided on or operatively associated with the tube member 10 to allow the entry but not the exit of air in relation to the assembly.

Claims

1. A bath aid unit comprising a seat member on which a user can sit, a support frame structure connected to the seat member and arranged to rest on the bottom of the bath, the support frame structure being displaceable between a first position in which the seat member is raised from the bottom of the bath and a second position in which the seat member is lowered at least substantially to the bottom of the bath, a power actuating unit comprising an electric motor and a gearbox and operable to produce displacement of said seat member to provide for raising and lowering movement thereof, and a plurality of means performing a water-resistant sealing effect to seal at least the motor and gearbox relative to the exterior of the power actuating unit.

2. A unit according to claim 1 wherein the support frame structure comprises first and second leg assemblies disposed in crossed scissor-like relationship with the leg assemblies pivoted together at their crossing point, the upper ends of the first and second leg assemblies being connected to said seat member for said raising and lowering movement thereof, and wherein said power actuating unit comprises a screw shaft connected to a portion of one of said leg assemblies and an electric motor-gearbox assembly connected to a portion forming part of or operatively associated with the other said leg assembly or said seat member, said gearbox of said electric motorgearbox assembly including drive means co-operating with said screw shaft for said raising and lowering movement of said seat member.

3. A unit according to claim 2 wherein said drive means includes a hollow shaft portion having a female screwthread therein meshing with the male screhread on said screw shaft, the shaft portion being rotatably mounted in casing portions of said actuating unit and capable of being driven in rotation through said gearbox, the arrangement being such that upon rotary movement of said shaft portion it is moved upwardly or downwardly along the screw shaft thereby to displace said seat member.

4. A unit according to claim 3 wherein said shaft portion is mounted in bearing means capable of resisting the ingress of water, thereby providing a respective one of said plurality of sealing means.

5. A unit according to claim 2 including a gaiter on said screw shaft to provide a respective one of said plurality of sealing means.

6. A unit according to claim 3 wherein said screw shaft is displaceable into the casing of the actuating unit upon downward displacement of said seat member and wherein said casing further includes within same an enclosure means for said screw shaft as it is displaced into the casing thereby to contain water penetrating into the casing along said screw shaft, thus providing one of said plurality of sealing means.

7. A unit according to any one of the preceding claims which further includes an alternative means of operating the power actuating unit manually for said raising or lowering movement of said seat member, for example in the event of failure of said power actuating unit.

8. A unit according to claim 7 wherein said alternatinve operating means includes a crank assembly capable of engaging a component of said actuating unit for rotation thereof to displace said seat member.

9. A unit according to claim 8 when appendant to claim 3 wherein said crank assembly is capable of engaging said shaft portion.

10. A unit according to claim 8 when appendant to claim 6 wherein said crank assembly is insertable into said enclosure means to engage said shaft portion.

11. A unit according to any one of the preceding claims and further including one-way valves to permit controlled flow of air through the power actuating unit.

12. A unit according to claim 11 when appendant to claim 5 and claim 6 wherein said valves comprise a one-way valve operatively associated with the gaiter to provide discharge of air therefrom and a further one-way valve operatively associated with said enclosure means to permit intake of air thereinto.

13. A bath aid unit substantially as hereinbefore described with reference to the accompanying drawing.