[0036] A perspective view of a bath 2 according to the invention is shown in FIG. 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.

[0037] The manner in which the door sealingly closes the opening 6 will be described with particular reference to FIGS. 2, 4, 5 and 6.

[0038] 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 FIG. 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.

[0039] Beneath the cladding panels 12 the bath includes a frame 20, shown in FIG. 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.

[0040] 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 to rotatably support pulleys 48 which are keyed to the axle 46 and thereby constrained to rotate together.

[0041] 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.

[0042] A linkage (shown in detail in FIG. 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.

[0043] 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.

[0044] 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 FIG. 4. When the door is in its closed position the counterweight beam 56 is in its lowered position as shown in FIG. 5. A sealing mechanism 74, shown in FIG. 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.

[0045] 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 FIG. 16) for controlling actuation of the door sealing motor 82.

[0046] A latch 68 (see FIG. 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.

[0047] 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 (FIG. 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 FIG. 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.

[0048] A complete operating sequence of the bath will now be described with particular reference to FIGS. 7 to 14.

[0049] With the door 8 held in the lowered position by the latch 68, as shown in FIG. 4, the counterweight 56, connected to the lower pivot pin 66, and omitted from FIG. 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 FIG. 8 and as this occurs the two chains 52 draw the door 8 up to its substantially fully raised position shown in FIG. 5.

[0050] The link arms 60 and 62 move to the position shown in FIG. 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 FIGS. 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 FIG. 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 FIG. 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.

[0051] 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.

[0052] 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 FIG. 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 FIG. 12 to that shown in FIG. 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.

[0053] 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 FIG. 4 at which point the latch 68 engages the door, or a part fixed thereto, and holds the door in its open position.

[0054] 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.

[0055] 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 FIG. 13 to that shown in FIG. 14 (in which the counterweight 56 is omitted form clarity).

[0056] While a particular embodiment has been described it will be understood that modifications may be made without departing from the scope of the invention.