BATH FOR INVALID

Abstract: A bath for a disabled person, the bath having a body with a side opening which is closable by a vertically displaceable door under the action of a door movement mechanism including a counter-weight beam (56) either end of which is linked to an end of the door by a chain. The weight of the counter-weight beam (56) is selected so as to bias the door towards its closed position. The beam (56) is connected by a pin (66) to over-centre lockable link arms (60, 62). When the beam approaches its lowermost position, as the door closes, a stub portion (72) of a pivot pin (64) connecting the link arms (60, 62) enters a locking fork (77) which is displaced by a motor (82) to effect over-centre locking of the link arms (60, 62) and thereby seal a channel on an inner face of the door against a lip disposed around the opening.

Description: BATH FOR INVALID The present invention relates to a bath particularly for an invalid, the bath having a side opening closed by a door which is openable to enable a person to enter or leave the bath. Such a bath is described in patent EP-A-0710080 which utilizes an actuator to rotate two pivotably interconnected V-shaped members relative to each other, each of which supports a roller engaging a channel on the bath's door, to cause the door to slide up to a closed position or down to an open position. Since the actuator needs to lift the door, it has to exert considerable force. As the door closes, a sealing strip in an inwardly facing channel projecting from an inner surface of the door is urged sealingly into engagement with an outwardly projecting lip positioned around the side opening. Accordingly, when the door is closed, the actuator not only needs to support the weight of the door but also hold the sealing strip firmly in engagement with the lip. Furthermore there is a danger that, as the door moves into its closed position, a user's fingers may become trapped between the lip and the channel. The force required to raise the door and effect complete sealing between the lip and the channel is of such a magnitude that such trapping of the fingers could result in serious injury occurring. An object of the invention is to provide an invalid bath with a door which requires less energy to close than those of prior art invalid baths and overcomes the disadvantage of finger entrapment referred to above. Thus according to the invention there is provided a bath particularly for use by an elderly or disabled person, the bath having a body with a side shaped so as to form an opening, a movable door arranged to selectively close the opening, guide means for guiding the door between open and shut positions and door actuating means for moving the door between the open and shut positions, the door actuating means including counterweight means connected to the door so as to substantially balance the weight of the door and bias it towards its shut position. The counterbalancing of the weight of the door will substantially reduce the amount of energy required to move the door between its open and shut positions and by providing a counterweight means of sufficient mass to bias the door towards its shut position, the need to drive the door towards the shut position can be avoided. This in turn avoids the danger of a user's fingers becoming trapped by a door being driven into its closed position. Preferably the counterweight means is connected to the door by a flexible load carrying means such as one or more belts or chains since these can be routed via small gaps to a location remote from the door such as at the back of the bath, thus contributing to the compactness of the design. The flexible load carrying means preferably passes round one or more pulley wheels. With such interconnection between the door and the counterweight means, preferably door weighs slightly less than the counterweight means and more preferably between 3% and 10% less. If the interconnection provides some kind of mechanical advantage however, the weights of these components need not so compare. The bath preferably includes a latch means arranged to latch the door in its open position so that the door will automatically be retained in that position once moved to it. Conveniently the bath includes mechanical latch release means so that the provision of an electrical device for this purpose is not necessary. Alternatively, the latch release means may be electromagnetically actuable in order that a conveniently positioned electrical switch may be provided to facilitate latch release by a severely disabled user. While the above counterbalancing will make it possible for a disabled user to move the door from its closed to its open position by merely pushing down on the door, a door lowering drive means may be provided to effect such movement of the door when the user is severely disabled. Conveniently the door actuating means includes a linkage, operatively connected to the counterweight means, which linkage is reconfigurable between first and second configurations to respectively open and close the door and simultaneously move the counterweight means between raised and lowered positions. Such a linkage can be designed to provide the required mechanical advantage and effect rapid opening and closing of the door. A linkage which will effect very rapid opening and closing of the door and can be "locked out" into an over centre configuration firmly holding the door in its closed position is one including first and second link arms interconnected by a first pivot, and a second pivot interconnecting a portion of the first link arm distal from the first pivot to the counterweight means. To effect the above-mentioned locking, preferably in its second configuration, corresponding to the door being closed, the first and second link arms are substantially aligned with each other. Conveniently a third pivot interconnects a portion of the second link arm distal from the first pivot to an anchor point fixed relative to the bath body. When the bath includes such a linkage, and particularly one having an over centre or locked out configuration, it preferably also includes a sealing mechanism arranged to act on a portion of the linkage to effect a seal between the door and the opening. An actuation mechanism for the sealing mechanism may be manually or electrically powered. Preferably the sealing mechanism includes a rack and pinion or screw engaging the rack for displacing it to provide a force for acting on the portion of the linkage. Such an arrangement provides advantageous mechanical advantage and good resistance to any unsealing movement of the linkage. Since urging a portion of the linkage which undergoes substantial displacement as the door moves between its two positions will provide high mechanical advantage as sealing of the door with the opening occurs, and so that the sealing mechanism need not accommodate such displacement, preferably the sealing mechanism includes an urging surface adjacent to which the portion of the linkage becomes positioned as the door substantially reaches its closed position. Preferably the urging surface is arranged to be displaced by the sealing mechanism actuation means to effect an over centre locking of the linkage. In order to obviate the requirement for a user to need to ascertain when the sealing mechanism has to be actuated and then arrested during a door closing and sealing operation, the bath preferably respectively includes a door shut sensor for sensing when the door substantially reaches its closed position and a sealing complete sensor for sensing when sealing between the door and the opening has been at least substantially completed. Since accidental opening of the door when any water is present in the bath would be undesirable, preferably the bath further includes locking means for preventing inadvertent opening of the door in such a situation. Preferably the locking means includes a lock actuating device which actuates the lock automatically when water is present in the bath so that the problem of a user forgetting to apply the lock once the door has been closed can be avoided. Conveniently the lock actuating device includes a low pressure water sensor which provides an electrical signal when water is present in the bath. The lock actuating device may alternatively or in addition include a movable member and fluid communicating means which enables pressure of water in the bath to cause the member to move and actuate the lock. When the sealing mechanism includes an electrical actuator, such as an electric motor, preferably the locking means effects locking of the door sealing mechanism by electric isolation of the electrical actuator of the sealing mechanism. If there is a requirement to minimise the number of electrical components incorporated into the bath, the locking means may effect such locking by means of a physical stop member, for example moved into the path of a link arm or associated port after over centre locking has occurred . Preferably the locking means includes means for automatic unlocking when the bath is substantially empty of water so that a user can simply push the door down to its open position when the bath has become substantially empty of water. In order to avoid complication in the design of the guiding means and the interconnection between the counterweight means and the door, the guide means preferably constrains the door to move substantially within its own plane as it moves from the open to the shut position and as sealing between the door and the opening in the bath body occurs . Sealing means for sealing between the body opening and door preferably comprises either a lip or a channel extending around the bath body opening which is sealingly engageable with the other of the lip or channel projecting from an inner surface of the door. A sealing strip may be interposed between the channel and the lip. With such an arrangement, sealing round the opening can be simply and effectively achieved using a straightforward movement of the door in one direction only. The invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a bath according to the invention including its cladding panels (which panels which are omitted or shown dotted in the other Figures) ; Figure 2 is a perspective view of a support frame, door and door actuating mechanism of the bath with the bath body itself omitted for clarity; Figure 3 is an end elevation of the support frame shown in Figure 2 from the direction of arrow A; Figure 4 is a side elevation of the support frame shown in Figure 2 from the direction of arrow B with the door in its open position; Figure 5 is a view similar to Figure 4 with the door in its closed position; Figure 6 is a detailed perspective view of the sealing mechanism and the linkage connecting the counterweight to the bath frame; Figures 7 to 14 show a schematic sequence of the parts shown in Figure 6 going through a door closing and opening cycle; Figure 15 is a cross-section on the line CC of the door shown in Figure 2 ; and Figure 16 is a schematic circuit diagram of a control unit and connected system elements for controlling opening and closing of the door. A perspective view of a bath 2 according to the invention is shown in Figure 1 and includes a body 4 for accommodating water, one side of which includes an opening 6 which is selectively closable by a door 8. Cladding panels 12 enclose the sides of the bath and are omitted from the other Figures for the purpose of clarity. The manner in which the. door sealingly closes the opening 6 will be described with particular reference to Figures 2, 4, 5 and 6. The opening 6 has upwardly diverging sides and a lip 14 projecting outwardly around the sides and bottom of the opening. A complementarily configured channel 16 is connected to and projects from an inner surface 10 of the door 8 and contains a sealing strip 18 which is forced into sealing engagement with the lip 14 as the door 8 is moved up into the closed position shown in Figure 5. Alternatively, the channel could be arranged around the edge of the opening and the lip 14 provided on the door. The sealing strip 18 could be connected to the lip 14 or the channel 16. Beneath the cladding panels 12 the bath includes a frame 20, shown in Figure 2, supported on four adjustable feet 22. The frame 20 includes quadrilateral end frames 24 interconnected by four longitudinal rails 26a, 26b, 26c and 26d. Each end frame front post 28 is slidingly engaged by a carriage 30 connected to inner surface 10 of the door 8 adjacent to one of its ends. The carriages 30 permit the door to slide upwardly into its closed position as described above and downwardly to open. Transverse beam members 32 interconnect the rails 26a-d and the two upper beam members support the water accommodating body 4 of the bath. The two rails 26a and 26b at the rear of the frame 20 support a vertical column 34 which projects upwardly above the upper rear rails 26a and is provided at its upper end with a bearing housing 36 which rotatably supports a horizontal upper pivot pin 38. A guide slot 40 is provided in a rear surface of the lowermost half of the column 34. A horizontal spindle 42 projects outwardly from an outer surface of each end frame 24 at the top of each end frame front posts 28 on which a pulley 44 is rotatably mounted. A horizontal axle 46 extends the length of the frame 20, passes through aligned holes in the end frame rear posts 29 and the columns 34 and projects outwardly from the end frames 24 tb rotatably support pulleys 48 which are keyed to the axle 46 and thereby constrained to rotate together. Closely adjacent each end of the door 8 and on its inner surface 10 an anchor bracket 50 is mounted to which one end of a chain 52 is connected via a first length adjuster 54. Each chain 52 extends upwardly from its associated anchor bracket 50, round the pulleys 44 and 48 respectively at the upper ends of the associated front post 28 and rear post 29 and downwards to one end of a horizontal counterweight beam 56 to which it is connected by a second length adjuster 58. The mass of the counterweight beam 56 is approximately 5% higher than the total mass of the door 8 including all items (carriages 30, anchor brackets 50, etc) which move up and down together. A linkage (shown in detail in Figure 6) comprising an upper link arm 60 and a lower link arm 62, the ends of which are pivotably interconnected by a central pivot pin 64, connects the upper pivot pin 38 and a lower pivot pin 66 journalled for rotation at the middle of the counterweight beam 56. The bottom of the lower link arm 62 is accommodated in an elongate slot 70 in an upper surface of the counterweight beam 56 which allows the lower link arm 62 to rotate relative to the counterweight beam 56. The lower pivot pin 66 projects from a front face of the counterweight beam 56 and is constrained to slide within the guide slot 40 in the rear face of the column 34 to restrain the counterweight beam 56 against lateral displacement . The central pivot pin 64 has a stub portion 72 which projects forwardly from the upper and lower link arms 60 and 62. When the door is in its open position the counterweight beam 56 is in its raised position as shown in Figure 4. When the door is in its closed position the counterweight beam 56 is in its lowered position as shown in Figure 5. A sealing mechanism 74, shown in Figure 6, is mounted on the column 34 adjacent to the position occupied by the stub portion 72 of the central pivot pin 64 when the counterweight beam 56 is in its lowered position. The sealing mechanism 74 includes a locking carriage 76 slidingly mounted on a rail 78 so as to be substantially horizontally displaceable by means of a pinion 80 driven by a door sealing electric motor 82 engaging a rack 84 mounted on the carriage 76. The motor 82 may have its rotation axis disposed parallel to the rail and drive the rack 84 by means of a screw element in place of the pinion 80. The carriage 76 has a locking fork 77 extending therefrom with two upwardly projecting tines defining first and second confronting urging surfaces 88 and 90 spaced apart along and substantially perpendicular to a longitudinal axis of movement of the carriage 76. The space between the tines 86 is upwardly open for receipt thereinto of the stub portion 72 of the central pivot pin 64 as described in detail below. Adjacent to the carriage 76 and slightly above it a sensor bracket 94 is connected to the column 34. The sensor bracket 94 supports first and second proximity sensors 96 and 98 the functions of which will described below. These sensors 96 and 98 are connected to control means 102 (see Figure 16) for controlling actuation of the door sealing motor 82. A latch 68 (see Figure 3) is provided on one or both sides of the door to retain the door in its fully opened position. This latch may be manually releasable to allow the door to rise or may be electrically releasable in which case a door latch release switch 104 is connected to the latch 68 via the control means 102. When water is present in the bath, a locking means prevents inadvertent unsealing and opening of the door 8. This locking means is preferably constituted by a water presence sensor 100 which is connected to the control means 102 which cuts off power to the door sealing motor 82 when water is sensed. Alternatively, the locking means may be constituted by a physical stop member 63 (Figure 6) which is displaced so as to lock the link arms 60 and 62 against movement out of their over-centre locked position when water is present in the bath. This may be effected by pressure resulting from such water displacing a moveable member linked to the stop member. When the bath is for use by a severely disabled person who would not be able to push the door 8 down against the gentle upward biasing provided by the counterweight 56, it may be provided with a door displacing motor 106 mounted on one end frame as shown in Figure 2 and provided with a chain pinion 108 for engaging one of the chains 52. The motor 106 would be controlled by a door lowering switch 110 via the control means 102. A complete operating sequence of the bath will now be described with particular reference to Figures 7 to 14. With the door 8 held in the lowered position by the latch 68, as shown in Figure 4, the counterweight 56, connected to the lower pivot pin 66 , and omitted from Figure 7 for clarity, will be in its raised position. After a user has entered the bath, the latch 68 is released either manually or by means of the switch 104 and the counterweight, which is slightly heavier than the door, moves down to the position shown in Figure 8 and as this occurs the two chains 52 draw the door 8 up to its substantially fully raised position shown in Figure 5. The link arms 60 and 62 move to the position shown in Figure 8 and, at the end of this movement, the stub portion 72 of the central pivot pin moves downwardly in an arcuate manner into the space between the two urging surfaces 88 and 90 of the locking fork 77 which together with its associated carriage 76 is at its most leftward position as seen in Figures 6 and 8. As this occurs, the upper link arm 60 becomes positioned adjacent to the first proximity sensor 96 which sends a signal to the control means 102 causing anticlockwise rotation of the door sealing motor 82 which, by means of its pinion 80 and carriage rack 84 draws the locking fork 77 to the right as seen in Figure 9 by engagement of the first urging surface 88 with the stub portion 72 of the central pivot pin 64. This movement causes the link arms 60 and 62 to undergo an over-centre locking action and urges the counterweight 56 further down which in turn forces the door 8 further upwards providing an effective seal between the sealing strip 18 in the channel 16 and the lip 14 around the opening 6. Completion of the over-centre sealing action is shown in Figure 10 and at this point the upper link arm 60 arrives adjacent to the second proximity sensor 98 which sends a signal to the control means 102 which stops rotation of the door sealing motor 82. The user then charges the bath with water which automatically actuates the locking mechanism. This may be by means of the water pressure sensor 100 sending a signal to the control means 102 which cuts off all power to the door sealing motor 82 preventing it from rotating in either direction. When bathing has been completed, water is drained from the bath in the usual manner and the unsealing and door opening sequence is initiated. This may be initiated automatically when the water sensor 100 detects an absence of water in the bath or may be initiated by actuation of a door unsealing switch 112 connected to the control means 102. The door sealing motor 82 rotates clockwise as shown in Figure 11 until the second urging surface 90 of the locking fork 77 comes into contact with the stub portion 72 of the central pivot pin 64 whereupon continued rotation of the door sealing motor 82 moves the link arms 60 and 62 through the over-centre locked position from the configuration shown in Figure 12 to that shown in Figure 13. Rotation of the door sealing motor 82 is continued until the presence of the upper link arm 60 adjacent to the first proximity sensor 96 results in a signal to the control means 102 arresting such rotation. Gentle downward pressure by the user on the upper surface of the door 8 then results in lowering of the door to its open position shown in Figure 4 at which point the latch 68 engages the door, or a part fixed thereto, and holds the door in its open position. If the user is particularly infirm, door lowering may be effected by pressing the door lowering switch 110 which causes the door displacing motor 106 to start up and drive the door down by means of its chain pinion 108 acting on the chain 52. As lowering of the door 8 occurs, the counterweight 56 is drawn upward and the link arms 60 and 62 become reconfigured from the arrangement shown in Figure 13 to that shown in Figure 14 (in which the counterweight 56 is omitted form clarity) . While a particular embodiment has been described it will be understood that modifications may be made without departing from the scope of the invention.

Claims: CLAIMS : 1. A bath (2) particularly for use by an elderly or disabled person, the bath having a body (4) with a side shaped so as to form an opening (6) , a movable door (8) arranged to selectively close the opening (6) , guide means (30) for guiding the door (8) between open and shut positions and door actuating means (52, 56, 74) for moving the door between the open and shut positions, the door actuating means (52, 56, 74) including counter-weight means (56) connected to the door so as to substantially counter-balance the weight of the door (8) and bias it towards its shut position. 2. A bath according to claim 1 wherein the door (8) weighs slightly less than the counterweight means (56) . 3. A bath according to claim 1 or 2 including latch means (68) arranged to latch the door (8) in its open position. 4. A bath according to claim 3 including manual latch release means. 5. A bath according to claim 3 including electromagnetically actuated latch release means. 6. A bath according to any preceding claim including door lowering drive means (106) . 7. A bath according to any preceding claim wherein the door actuating means includes a linkage (60, 62) operatively connected to the counter-weight means (56) which linkage is reconfigurable between first and second configurations to respectively open and close the door and simultaneously move the counter-weight means (56) between raised and lowered positions. 8. A bath according to claim 7 wherein the linkage includes first and second link arms (60, 62) interconnected by a first pivot (64) and a second pivot (66) interconnecting a portion of the first link arm (62) distal from the first pivot (64) to the counter-weight means (56) . 9. A bath according to claims 7 and 8 wherein in its second configuration, corresponding to the door (8) being closed, the first and second link arms (60, 62) are substantially aligned with each other. 10. A bath according to claim 8 or 9 wherein a third pivot (38) interconnects a portion of the second link arm (60) distal from the first pivot (64) to an anchor point (36) fixed relative to the bath body (4) . 11. A bath according to any one of claims 7 to 10 wherein the door actuating means includes a sealing mechanism (74) arranged to act on a portion (72) of the linkage to effect a seal between the door (8) and the opening (6) . 12. A bath according to claim 11 including manual sealing mechanism actuation means . 13. A bath according to claim 11 including electric sealing mechanism actuation means (102, 112) . 14. A bath according to claim 12 or 13 wherein the sealing mechanism (74) includes a rack (84) and a pinion (80) or screw engaging the rack (84) and displacing it to act on the portion (72) of the linkage (60, 62) . 15. A bath according to any one of claims 11 to 14 wherein the sealing mechanism (74) includes an urging surface (88) adjacent to which the portion (72) of the linkage (60, 62) becomes positioned as the door (8) substantially reaches its closed position. 16. A bath according to claim 15 wherein the urging surface (88) is arranged to be displaced by the sealing mechanism (74) to effect an over-centre locking of the linkage (60, 62) . 17. A bath according to any one of claims 11 to 16 including a door shut sensor for sensing when the door (8) substantially reaches its closed position. 18. A bath according to any one of claims 11 to 17 wherein the sealing mechanism (74) includes a sealing complete sensor (98) for sensing when sealing between the door (8) and the opening (6) has been at least substantially completed. 19. A bath according to any preceding claim including locking means (100, 102) for preventing inadvertent opening of the door (8) . 20. A bath according to claim 19 wherein the locking means (100, 102) includes a lock actuating device which actuates the lock automatically when water is present in the bath . 21. A bath according to claim 19 or 20 wherein the lock actuating device includes a water sensor (100) which provides an electrical signal when water is present in the bath. 22. A bath according to any one of claims 19 to 21 and claim 13 or any claim dependent thereon wherein the locking means (100, 102) effects locking of the door sealing mechanism (74) by electric isolation of an electrical actuator (82) of the sealing mechanism (74) . 23. A bath according to any one of claims 19 to 21 wherein the locking means effects locking by means of a physical stop member (62) . 24. A bath according to any of claims 19 to 23 wherein the locking means (100, 102) includes means for automatically unlocking when the bath is substantially empty of water. 25. A bath according to any preceding claim wherein the guide means (30) constrains the door (8) to move substantially within its own plane as it moves from the open to the shut position and as sealing between the door (8) and the opening (6) in the bath body (4) occurs. 26. A bath according to any preceding claim including sealing means (18) for sealing between the body opening (6) and the door (8) comprising either a lip (14) or a channel (16) extending around the body opening (6) which is sealingly engageable with the other of the lip (14) or channel (16) projecting from an inner surface (10) of the door (8) .

Inventors: APPLEFORD DAVID ERIC, LANE BRIAN WILLIAM, APPLEFORD, DAVID, ERIC, LANE, BRIAN, WILLIAM
Applicants: ACER PROD LTD, APPLEFORD DAVID ERIC, LANE BRIAN WILLIAM, ACER PRODUCTS LTD., APPLEFORD, DAVID, ERIC, LANE, BRIAN, WILLIAM
Application year: 2001
Main classification: A47K3
IPC codes: A47K3