GB2203128A

GB2203128A - Invalid lift

Info

Publication number: GB2203128A
Application number: GB08707459A
Authority: GB
Inventors: John Charles Payne; Leslie Cyril Fensom
Original assignee: F J PAYNE
Current assignee: F J PAYNE
Priority date: 1987-03-28
Filing date: 1987-03-28
Publication date: 1988-10-12
Anticipated expiration: 2007-03-28
Also published as: GB2203128B; GB8707459D0

Abstract

A bath lift having a winder-operated telescopic extensible lifting column for raising and lowering a seat support arm and seat. The lifting column has four co-axial members: an outer, fixed, base-mounted vertical tube 6 and an extending rotatable tube within 7, carrying the seat support arm. Inside the extending tube is a fixed lower tube 10 having a threaded nut 13 at the top and, innermost, a screw threaded shaft 14 passing through the nut and winder-rotated to extend or retract the rotatable tube. The seat is rotatable about the lifting column and is lockable in preferred positions by a lock 40. The lock has a castellated stator cylinder fixed to the outer fixed tube and a rotor cylinder fixed to the rotatable tube within. The lock operates by a latch which locks the stator and rotor members. The winder is offset from the screw threaded shaft by spaced sprockets 21, 25 and chain drive, 26. <IMAGE>

Description

Improvements in or relating to Apparatus for Lifting Disabled Persons Description of the Invention This invention relates to apparatus for lifting disabled persons. In particular, the invention provides apparatus for lifting a seated disabled person into and out of a bath, such apparatus being adapted for selfoperation by the disabled person. Such apparatus is widely called a "bath lift".

This invention provides a bath lift of alternative and improved construction to known bath lifts.

Short Description of the Drawings A preferred embodiment of the invention will be described in detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an elevation view of the complete bath lift; Fig. 2 is a longitudinal section view -of the bath lift of Fig. 1, in a plane at right angles to the plane of Fig. 1; and Fig. 3 is a detail view of a locking mechanism shown in Fig. 2.

Corresponding elements are indicated by the same reference numerals in the different views.

Description of the Embodiment As shown in Figs. 7 and 2, the bath lift apparatus comprises a vertical, extensible lifting column 1, a support arm 2, carried by the lifting column 1 and supporting a seat 3, see Fig. 1, and an offset arm carrying a winding handle 5 at its outer end, for raising or lowering the lifting column 1 and with it the support arm 2 and seat 3.

In the view of Fig. 1, the offset arm 4 extends forwardly of the plane of the drawing. In the view of Fig. 2, the support arm 2 extends forwardly of the plane of the drawing.

Considered in greater detail, the lifting arm 1 is of telescopic form having an outer, fixed tube 6 and an internal, sliding tube 7. The outer tube 6 is welded at its lower end to a flanged socket 8 which is itself bolted to a floor plate 9.

The floor plate 9 enables the bath lift to be floor mounted alongside a bath, not shown in the drawings, at either side of the bath. In the view of Fig. 1, with the support arm 2 and seat 3 in the position shown, the bath lift would be mounted so that the seat 3 was aligned with the bath centre line.

The operation of the bath lift is conveniently considered from an initial position in which the support arm 2 and seat 3 are lowered outside the bath, the support arm 2 extending lengthwise of the bath and the seat 3 backing the side of the bath. The bath lift is fixed in this position by locking means to be described.

The disabled person seats himself with the bath lift in this position. The support arm 2, seat 3 and occupant are then raised by winding the winding handle 5. The locking means is released, the seat 3 is swung over the bath, the support arm 2 is re-locked in this position and the seat 3 is lowered into the bath by the winding handle 5. The disabled person is removed from the bath by the reverse series of operations.

Continuing, now, with the detailed description of the bath lift and with the view of Fig. 2, an inner tube 10 of square cross-section is positioned co-axially of the outer tube 6 and is fixed in relation thereto by a transverse pin 11 passing through the socket 8 and by spacing pieces 12. The top end of the tube 10 carries a nut 13 which receives a threaded shaft 14. The threaded shaft 14 also is coaxial with the lifting column tubes 6 and 7 described and is rotated about this axis by the winding handle 5, in the manner to be described, so that it may rise or fall within the nut 13 to lift or lower the sliding tube 7, the support arm 2 and seat 3 and the offset arm 4. The threaded shaft 14 carries a limit washer 15 and securing nut 16 at its lower end, to limit its upwards travel in the nut 13.

The upper end 14' of the threaded shaft 14 is of reduced, circular cross section.

As also shown in the view of Fig. 2, the top of the sliding tube 7 has a bush 17 welded therein. The bush 17 faces with a bush 18 which is secured in the base plate 19 at the inner end of the offset arm 4 Both bushes 17 and 18 carry a cylindrical bearing member 20 through which the cylindrical upper end 14' of the threaded shaft 14 passes. The top end of the shaft 14 has a chain sprocket 21 pinned thereto.

A flared bush 22, secured in the base plate 19 at the outer end of the offset. arm 4, also carries a cylindrical bearing member 23. The rotating shaft 24, from which the winding handle is offset by an intermediate crank, passes through the bearing member 23 and has a chain sprocket 25 pinned to its end. The offset arm 4 is hollow and encloses both the sprockets 21 and 25 described and also a chain 26 which passes around both sprockets 21 and 25. The threaded shaft 14 is thus rotated, to raise the sliding tube 7 of the lifting column 1, by means of the winding handle 5, through the chain and sprocket drive 25, 26 and 21.

In the view of Fig. 2, a clamp 27 is shown surrounding the top of the tube 7 and the bush 17 welded thereto. The clamp 27 carries the support arm 2 and seat 3, details of which are more clearly seen in the view of Fig. 1. The clamp 27 is secured by two tightening screws 28 and has an integral spigot 29 upon which the upper part of the support arm 2 is located and secured by a hand-screw 30. The lower end of the support arm 2 carries a tubular frame 31 to which a plastics seat 3 is fastened.

Returning to the view of Fig. 2, there is shown a cylindrical boss 32 which is pinned to the shaft 14 at the lower end of the circular section portion 14'. The top face of the boss 32 carries the lower part of a thrust bearing 33, the upper part of which bearing bears against the underside of an upper cylindrical boss 34. This boss in turn bears against the underside of the bush 17 through an intermediate washer 35. By these means, the weight of the seat 3 and occupant, together with the weight of the support arm 2, the offset arm 4 and winding mechanism is transmitted by way of the thrust bearing 33, the threaded shaft 14 and nut 13, the square-section tube 10 and pin 11 to the base members of the bath lift, socket 8 and floor plate 9.

A helical locking spring 36 surrounds both bosses 32 and 34, so as to lock these two members in the rotational sense corresponding to the lowering of the lifting column 1. Without the locking spring 36, the support arm 2 and seat 3 would tend to rotate about the lifting column axis by reason of the weight thereof and due to the threaded shaft 14 running downwards through the nut 13. With the locking spring 36, the friction at the faces of the washer 35 and between the rotatable tube 7 and its bushing surfaces, to be described, effectively prevent any such free rotation.

In the views of Fig. 1 and Fig. 2, the rotational locking means is generally referenced at 40. This locking means will be described in detail with reference to Fig. 3.

As was stated earlier herein, the operation of the bath lift requires the locking means 40 to lock the rotation of the support arm 2 and seat 3, about the lifting column 1 axis, in two positions, one outside the bath, for receiving the disabled person, and one over the bath, for lowering the disabled person into the bath. The facility for the bath lift to be mounted at either side of the bath requires the provision of an alternative pair of locking positions, hence four locking positions in all are provided.

As is shown in Fig. 3, the fixed outer tube 6 of the lifting column 1 has a ring 41 welded near the top thereof. The ring 41 has four location holes 42 drilled at 900 intervals around the ring 41. Two location holes 42 are shown in the view of Fig. 3. A castellated, hollow, cylindrical hub 43 is rotationally located and secured to the ring 41 by four grub screws 44 which register with the location holes 42. Two grub screws 44 are shown in the view of Fig. 3. The hub 43 has a castellated top face providing four castellations in the form of slots 45 at 900 intervals extending parallel to the lifting column axis. Two such slots 45 are seen in the view of Fig. 3. The four slots 45, co-operating with a locking key 46, provide the four locking positions required.The hub 43 also retains a cylindrical nylon bush 47, which provides a bearing surface for the axially rotatable internal sliding tube 7.

Extending a little below the castellated top portion, the hub 43 is of greater internal diameter and receives and positions axially a location collar 48.

The top of the collar 48 retains an annular wiper seal 49 which bears against the outer surface of the sliding tube 7 to remove condensed or splashed moisture therefrom, as the tube 7 is lowered into the tube 6. The hub 43 also retains and positions a cover tube 50, which is secured to the hub 43 by three equally spacedapart drive screws 51, one of which is seen in the view of Fig. 3.

As also seen in the view of Fig. 3, the inner face of the location collar 48 has a part-cylindrical ream 52 which receives a solid cylindrical brass sliding key 53. The inner lengthwise portion of the sliding key 53, which is not accommodated within the ream 52, extends into a lengthwise groove cut into the outer face of the sliding tube 7, parallel to its axis.

Whereas, the hub 43 is rotationally fixed to the fixed outer tube 6, the location collar 48, cover tube 50, and other locking elements to be described, are all rotationally fixed to the sliding tube 7, which itself is axially rotatable relatively to the fixed outer tube 6. It will be recalled, from the earlier description, that the support arm 2, seat 3 and the offset arm 4 and winding handle 5 are all rotationally fixed relatively to the sliding, and rotatable, tube 7. This feature ensures that, whatever the axial rotation of the support arm 2 and seat 3 about the lifting column 1 axis, the winding handle 5 and the locking means 40 are always in the same position relatively to the seat 3 and hence to the seat occupant.

Continuing with the detailed description of the locking means 40, with reference to Fig. 3, the location collar 48 has a flat surface machined opposite the ream 52 which receives a pivot mount 54 to which the locking key 46 is pivotally attached by a pivot pin 55. Extending from the locking key 46 is a locking key handle 56 terminating at a knob 57. Welded to the cover tube 50 is a slotted guide 58, within which the locking key handle 56 may travel. A helical compression spring 59 abuts the locking key 46 and exerts pressure against a spring retaining plate 60. The spring retaining plate 60 is bent downwardly at its outer ends to locate against the sides of the slotted guide 58.The slotted guide 58 is made of such length that, in the raised position of the locking handle 56 shown in Fig. 3 the handle is at top-dead-centre, or may be a little beyond top-dead-centre, with regard to the pivot axis 55 and the face of the slotted guide 58, so that the locking handle 56 retains its raised position when once positioned there. When the locking handle 56 is lowered, -the compression spring 59 urges the locking handle 56 to the position in which the inner face of the locking key 46 abuts the side face of the hub 43, which it will be recalled is rotationally fixed. As sliding tube 7, with the support arm 2 and seat 3, and the locking means 40 continue to rotate, the locking key 46 auto matically locks the structure against further rotation, when it locates with and enters any one of the four castellation slots 45. The rotational position is thereby held while the lifting column 1 is raised or lowered by operation of the winding handle 5.

Claims

1. Apparatus for lifting and lowering a seated disabled person, particularly a bath lift, comprising a winderoperated telescopic extensible lifting column, a seat support arm carried by and lifted by the lifting column and locking means for locking the seat support arm in alternative rotational positions around the lifting column axis, the lifting column comprising a fixed outer tube for mounting vertically from a base support, particulary alongside a bath, and an axially-rotatable extensible inner tube carrying the seat support arm fixed thereto.

2. Apparatus as claimed in Claim 1, in which the locking means includes a sleeve attached to the fixed outer tube, a relatively rotatable sleeve slidably-attached to the extensible inner tube for rotation therewith and a latch for locking the sleeves in alternative relative rotational positions.

3. Apparatus as claimed in Claim 2, in which the latch locking the sleeves is operated by a handle and carried by a pivot mount on the sleeve which is slidable-attached to the extensible inner tube.

4. Apparatus as claimed in any one of Claims 1 to 3, in which the winder-operated telescopic extensible lifting column further includes a fixed lower tube, extending within the rotatable extensible tube and carrying a threaded nut and, extending within the fixed lower tube, a screw threaded shaft rotatable by the winder, for extending and retracting the rotatable extensible tube.

5. Apparatus as claimed in Claim 4, in which the screw threaded shaft is rotated by the winder, mounted at the end of an offset arm, by way of a pair of sprockets and an intermediate chain drive.

6. Apparatus as claimed in Claim 5, in which the offset arm is attached to the rotatable extensible tube for rotation therewith about the lifting column axis.

7. Apparatus as claimed in any one of the preceding claims, in which the seat support arm is detachable attached to a spigot mounted on the rotatable extensible tube.

8. Apparatus as claimed in Claim 1, constructed substantially as described herein with reference to the accompanying drawings.