GB2361181A

GB2361181A - Lifting apparatus for use in a bath

Info

Publication number: GB2361181A
Application number: GB0009147A
Authority: GB
Inventors: Benjamin Cain
Original assignee: AQUASOOTHE Ltd
Current assignee: AQUASOOTHE Ltd
Priority date: 2000-04-14
Filing date: 2000-04-14
Publication date: 2001-10-17
Also published as: GB0009147D0

Abstract

Lifting apparatus 1, of the type used to lower or raise disabled people into or out of a domestic bath, has a belt 10 for supporting a person during lifting. Winding in the belt 10 lifts the person and winding out the belt 10 lowers them. Requests to wind in or wind out the belt are made using the push buttons 26, 28 on the front of a unit 8. Within unit 8 the belt 10 is wound around a roller 30 driven by a motor 42. Once wound out, the belt 10 is prevented from re-winding in the wrong direction by limiting means which inhibits the motor 42 from continuing to drive the roller 32 in the winding out direction.

Description

2361181 Lifting Apparatus The invention relates to lifting apparatus of

the type suitable for lifting people into and out of domestic baths.

People who are physically impaired, such as the old or disabled, have difficulty getting into and out of domestic baths. In the UK a number of bathing aids are available for such people. For example, under the designation Easybather the applicant supplies apparatus for lowering a person into a bath. The main lifting component of the applicant's apparatus is a belt extending from a unit mounted on one side of the bath, over the edge of the other side of the bath and down to the floor, where it is anchored. The belt winds around a roller in the unit and may be wound in or out of the unit to raise or lower the belt respectively. The roller is driven by a motor operable in either of two directions according to whether the belt is to be wound in or out.

The applicant's apparatus is used as follows: initially, the belt is wound out sufficiently to enable it to be anchored to the floor, with a length of the belt stretched taut more or less at bath edge level. A mechanism is provided for maintaining constant tension in the belt. A person wishing to get into the bath sits on the taut belt and lowers themselves by pressing and holding one of two buttons which actuates the motor to drive the roller in the winding out direction. When they reach the bath bottom, the button is released. When they want to get out of the bath, they raise themselves back up to bath edge level by pressing and holding the second of the buttons which actuates the motor to drive the roller in the opposite, winding in direction.

Steps have been taken with the applicant's apparatus to prevent excessive winding out of the belt. Continued pressing of the "winding out" button will cause the roller to continue to rotate in the wind out direction. However, after the belt has wound out to its fullest extent, continued rotation will result in the belt rewinding around the 1 roller in the opposite direction. Thus, once the belt has rewound, the winding out button will serve the purpose of the "winding W' button, and the roll of each button is reversed. This is not of itself a major problem, but the automatic tensioning mechanism is configured to work in conjunction with the winding in button. Hence, if the winding out button is used to wind in the belt, the automatic tensioning mechanism will not function correctly when the belt achieves the required tautness. Strips are printed onto or woven into the belt close to the end attached to the roller and users are warned not to unwind the belt beyond the warning strips. Nevertheless, a number of users still fail to heed these warnings and what is required is a fail- safe means of preventing excessive winding out of the belt.

The invention provides lifting apparatus comprising a belt for supporting an article during lifting, winding means operable in either one of two directions to cause the belt to wind in or out respectively, wherein winding in the belt raises a supported article and winding out the belt lowers a supported article, control means for receiving a request from a user either to wind in or to wind out the belt and controlling the winding means to operate in the direction appropriate to the user request, and limiting means which detects when the belt has wound out to a predetermined extent and in response thereto inhibits the winding means from continuing to operate in the direction which would cause further winding out.

Preferably, the winding means comprises a roller around which the belt is wound and drive means for rotating the roller in either direction. Further preferably, the drive means comprises an electric motor which drives the roller through an output shaft, the control means comprises electronic circuitry including a switch which controls the delivery of power from a source to the motor, and the limiting means comprises an extension to the motor output shaft, which serves as a lead screw for a cam to travel therealong in relation to the winding in and out of the belt, wherein the cam is adapted to actuate the switch. Alternatively preferably, the limiting means comprises any electronic or electrical means capable of detecting the extent to which the belt has wound out and actuating the switch. Examples of such alternative electronic or 2 electrical means are as follows: A magnetic strip may be attached to, for instance sewn into, the belt at an appropriate position so as to be detected by a reed switch, or other magnetic sensor, when the belt has wound out to the predetermined extent; a reflective strip attached to, for instance sewn or glued on to, the belt, at the appropriate position may be detected by an optical detector; an appropriately positioned hole in the belt may be used to control light reading an optical detector; a rigid flag may be attached to the edge of the belt at an appropriate position so as to physically actuate the switch which needs to be located adjacent the belt; the number of revolutions of any revolving part, such as a gear or output or drive shaft, may be counted by using appropriate counting means, such as magnets and a magnetic sensor, a optical encoder and a vane or a gear tooth detector, and the switch will be actuated when the count reaches the number of revolutions predetermined to correspond to the maximum allowable winding out of the belt. The counter needs a datum at which to start and may operate in conjunction with an integrated circuit or microprocessor. A specific example of a counting system includes a cam mounted on an drive shaft which trips a microswitch with each revolution of the shaft, and the number of trips is monitored as a measure of the extent of the winding out of the belt.

A limit switch tripped when the belt is wound in as far as possible offers a means of marking a datum.

The apparatus also preferably comprises means for controlling the tension in the belt.

The power source may be DC, and may be a rechargeable battery, although the apparatus may be made to operate with whatever power source is available and allowable in the circumstances of its use.

A request from the user either to wind in or wind out the belt may each be made with a separate push button which may be sited with the remainder of the apparatus or in a remote handset which could have a wired or wireless link to the remainder of the apparatus.

3 The article may be a user and the apparatus according to the invention is particularly suited to use for lifting a person in to and out of a domestic bath.

The invention will now be described, by way of example, with reference to the 5 following drawings in which:

Figure 1 is an illustration of the apparatus according to the invention installed in a domestic bathroom; Figure 2 is a front view of part of the inside of the a used in apparatus according to the invention; Figure 3 is a top view of the inside of the unit shown in figure 2; and Figure 4 is a cross sectional side view of a unit and belt used in apparatus according to the invention.

Shown in figure 1 is a domestic bath 2 located adjacent a wall 4. Fitted to the wall 4, just above one longitudinal edge 6 of the bath 2, is the lifting unit 8 of lifting apparatus, indicated generally at 1, according to the invention. The apparatus 1 further comprises a belt 10 which extends from the unit 8, through a slot 12, over the opposite longitudinal edge 14 of the bath 2 and down to the floor 16. At the free end 18 of the belt 10 a locating bar 20 is attached, which hooks under a captivating member 22, generally of an upturned J-shape in cross-section. The captivating member 22 is fastened to the floor 14 so as to anchor the free end 18 of the belt 10.

Within the unit 8 there is a winding mechanism for winding the belt 10 in and out.

The mechanism is powered by a 24V DC rechargeable battery 24 mounted on the wall 4 alongside the unit 8. Actuation of the winding mechanism is controlled by push buttons 26, 28; one 26 for actuating winding in and the other 28 for actuating winding out.

4 In the in-operative state of the lifting apparatus 1, the belt 10 is wound in to the unit 8 with only the free end 18 and the attached locating bar 20 visible. When the apparatus 1 is needed for lowering a user (not shown) into the bath 2, a request to wind out the belt 10 is made by pressing and holding the winding out push button 28, and the belt 10 is extended sufficiently to hook the locating bar 20 under the captivating member 22. Excess slack in the belt 10 is then taken up by the user making a request to wind in the belt 10, which involves pressing and holding the winding in button 26. The belt 10 will wind in until it reaches a predetermined tension, at which point further winding in will be prevented. This is achieved by means of an automatic tensioning arrangement (described in more detail later). After these operations are complete, the apparatus 1 is set up as shown in figure 1, with the belt 10 held generally at bath edge 6, 14 height and ready for a user who wishes to get into the bath 2 to sit themselves thereon. Once comfortable and stable, the user presses and holds the winding out button 28 and the belt 2 winds out, lowering them into the bath 2. The user continues to press the winding out button 28 until they are seated on the bath bottom. When they have finished bathing, and wish to get out of the bath, the user presses and holds the winding in button 26 until the belt 2 and they are returned to bath edge 6, 14 height.

The winding out of the belt 10 is limited such that either during the initial operation of anchoring the belt 10 or when lowering themselves into the bath 2, there is a limit to the extent to which the user may wind it out. At a certain pre- determined point in the extension of the belt 10, continued pressing of the winding out button 28 will not effect further winding out. Only the winding in button 26 will then be enabled.

The winding mechanism housed within the lifting unit 8 shown in figure 1 illustrated in greater detail in figures 2 and 3. The belt 10 is wound around a roller which is driven in either direction in rotation by a motor 32 through two interengaging gears 34, 36. The operation of the motor 32 is controlled by electronic circuitry (not shown) mounted on a circuit board 38. The electronic circuitry is responsive to the actuation of the push buttons 26, 28 effectively to alter the polarity of the power applied to the motor 32 according to the required direction of rotation of the roller 30. Also mounted on the circuit board 38 as part of the electronic circuitry is a microswitch 39 whose actuation prevents further power, which would result in it 5 continuing to rotate in the wind out direction, from being applied to the motor 32.

The primary driving gear 34 is fast with the main output shaft 40 of the motor 32. The secondary driving gear 36 is fast with the centre spindle 41 of the roller 30. The output shaft 40 is supported at either end by bearings 42, 44 which, in the case of the bearing 44 at the end of the shaft 40 remote from the motor 32, is supported by a mounting member 46, which is screwed to the body of the unit 8. The mounting member 46 is adjacent one end of the roller 30 and there is a corresponding mounting member 48 adjacent the other end of the roller 30. Between the two mounting members 46, 48, extending longitudinally of the unit 8, is a dividing plate 50. An extension shaft 52 of the output shaft 40 extends beyond the remote bearing 44, and is supported at its end furthest from the remote bearing 44 by a further bearing 54 mounted on a bracket 56 fixed to the dividing plate 50. The extension shaft 52 is threaded and rotates with the output shaft 40, thereby serving as a lead screw. A cam 58 is threadably received on the extension shaft 52 and travels therealong as the output shaft 40 rotates. The extension shaft 52 is so arranged that the cam 58 may travel to a position at which it engages and actuates the microswitch 39. Thus, by calibrating the cam 58 such that it moves to the position at which it engages the micro switch 39 when the drive shaft 40 has been through the number of rotations necessary to unwind the belt 10 to near to its fullest extent, and thereby inhibits the continued delivery of power to the motor 32, further potentially detrimental unwinding of the belt 10 is inhibited. However, a winding in actuation is not inhibited, and the motor 32 will respond to the user pressing the winding in button 26.

With further reference to figure 4 which shows the automatic belt tensioning mechanism indicated generally at 59 comprising an arm 60 which is pivotally 6 mounted to a rod 62 extending longitudinally of the unit 8. The arm 60 hangs generally downwards but is urged by a spring 64 towards the rear of the unit (that is, to the left as viewed in figure 4) and towards the belt 10, whose path from the roller is between the arm 60 and the rear of the unit 8 (the path being shown as though across the top of a bath in the manner described with reference to figure 1 although the bath is not illustrated). The arm 60 controls the actuation of another microswitch 66 which makes or breaks the power supply to the motor 32 during a winding in operation. When the belt 10 is slack, the arm 60 is urged to the rear of the unit 8 and the microswitch is not actuated. If a winding in operation is then initiated by pressing and holding the winding in button 26, the belt 10 will, because it is anchored at the free end 18, eventually become taut as shown in figure 4. During the process of tightening, the belt 10 engages the arm 60 and forces it to the right, towards the front of the unit 8. Once the arm 60 has been urged a certain distance to the right, which is pre- detennined according to the required tension in the belt 10, the arm 60 will depress and actuate the microswitch 66, thereby breaking the power supplied for winding in. Thus, continued pressing of the winding in button 26 will have no effect. However, if an article is placed on the belt 10, causing the tension to alter and the arm 60 to be urged to the left, the microswitch 66 will be released and the belt 10 can again be wound in to the pre-determined tension.

If the cam operated microswitch 39 was not in place, a user could continue to hold down the winding out button 28 such that the belt 10 would wind completely out and then begin to rewind around the roller 30. Consequently, the winding out button 28 would then function as the "winding in" button and vice versa. As the automatic tensioning mechanism 59 is intended for use only with the winding in button 26, it would not function properly when brought into play as a result of the belt 10 being wound to the taut position using the winding out button 28.

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Claims

Claims

Lifting apparatus comprising a belt for supporting an article during lifting, winding means operable in either one of two directions to cause the belt to wind in or out respectively, wherein winding in the belt raises a supported article and winding out the belt lowers a supported article, control means for receiving a request from a user either to wind in or to wind out the belt and controlling the winding means to operate in the direction appropriate to the user request, and limiting means which detects when the belt has wound out to a pre-determined extent and in response thereto inhibits the winding means from continuing to operate in the direction which would cause further winding out.
2. Lifting apparatus according to claim 1 wherein the winding means comprises a roller around which the belt is wound and drive means for rotating the roller in either direction.
Lifting apparatus according to claim 2 wherein the drive means comprises an electric motor.
4.

Lifting apparatus according to claim 3 wherein the control means comprises electronic circuitry including switch means which controls the delivery of power from an electrical source to the motor.
5. Lifting apparatus according to claim 4 wherein the limiting means actuates the switch means.
Lifting apparatus according to claim 5 wherein the motor drives the roller through an output shaft and the limiting means comprises an extension to the motor output shaft, which serves as a lead screw for a cam to travel 8 therealong in relation to the winding in and out of the belt, wherein the cam is adapted to actuate the switch means.
7. Lifting apparatus according to claim 4 wherein the switch means comprises a 5 microswitch.
8. Lifting apparatus according to claim 5 wherein the limiting means comprises electronic or electrical means adapted to detect the extent to which the belt has wound out and to actuate the switch means.
9. Lifting apparatus according to any preceding claim flirther comprising means for controlling the tension in the belt.
10. Lifting apparatus according to any preceding claim comprising first and second push buttons each for a user to make a request either to wind in or wind out the belt respectively, which push buttons are sited with the remainder of the apparatus or in a remote handset which has a wired or wireless link to the remainder of the apparatus.
11. Lifting apparatus substantially as herein described with reference to figures 1 to 4 of the drawings.

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