GB2289258A

GB2289258A - Invalid hoist

Info

Publication number: GB2289258A
Application number: GB9409210A
Authority: GB
Inventors: John Greaves
Original assignee: Arjo Ltd
Current assignee: Arjo Ltd
Priority date: 1994-05-10
Filing date: 1994-05-10
Publication date: 1995-11-15
Also published as: GB9409210D0; WO1995030401A1; AU2349895A; ZA953723B; TW268895B

Abstract

A mobile invalid hoist has a lifting arm projecting from an upstanding support structure or column 11 mounted on a chassis, wherein the chassis comprises a main portion 12 supporting the support structure or column, and two chassis side members 13 which project forwardly from the main portion in parallel spaced relationship. The side members are connected to respective transverse guide members 14 which are supported by the main chassis portion for slidable movement relative thereto. The chassis also comprises a pair of lever arms 16 each of which is pivotably connected at one end to the main chassis portion and at their other ends to the two guide members, respectively, and means 20, 21, 26 for pivoting the two lever arms simultaneously to effect simultaneous and parallel movement of the side members away from or towards the main chassis portion. Preferably the means 20, 21, 26 comprise a motor 20, a drive belt 26 and a screw actuator 21. <IMAGE>

Description

Invalid Hoists This invention relates to invalid hoists of the type comprising a lifting arm projecting from an upstanding support structure or column mounted on a mobile chassis.

Hoists of this type commonly have a chassis which is open at the front between side members of the chassis with the support structure or column mounted adjacent to the rear of the chassis which is supported on front and rear castors. With such an arrangement it is known for the chassis to be of adjustable width, with the side members pivoted adjacent to the rear of the chassis, to provide a minimum width for use in confined spaces and passing through doorways whereas the width of the front opening can be increased to fit around a wheelchair, for example.

With such an arrangement, the width of the chassis at the rear thereof is fixed and this can limit the extent to which the chassis can fit around a wheelchair or under a bed.

According to the present invention, there is provided a mobile invalid hoist having a lifting arm projecting from an upstanding support structure or column mounted on a chassis, wherein the chassis comprises a main portion supporting the support structure or column, and two chassis side members which project forwardly from the main portion in parallel spaced relationship, the side members being connected to respective guide members which extend transversely of the longitudinal extent of the side members and which are supported by the main chassis portion for slidable movement relative thereto, a pair of lever arms each of which is pivotably connected at one end to the main chassis portion and which are pivotably connected at their other ends to the two guide members, respectively, and means for pivoting the two lever arms simultaneously to effect simultaneous movement of the side members away from or towards the main chassis portion, the side members remaining in parallel spaced relationship over the extent of their movement.

Parallel opening of the side members improves accessibility of the chassis and also renders the hoist more stable.

Preferably, the pivoting means is power operated and, in this case, the pivoting means may comprise screw-threaded actuator means extended and retracted by an electric motor.

Preferably, the lever arms extend in a direction parallel to the side members when the side members are substantially midway between outermost and innermost positions.

Preferably, the guide members and lever arms are below a top plate of the main chassis portion.

Preferably, the main chassis portion is provided with two ground-engaging support castors and each side member is provided with a ground-engaging support castor at or adjacent to its front end.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of part of one embodiment of an invalid hoist according to the invention, Figure 2 is a plan view of part of the chassis of the invalid hoist shown in Figure 1, with the top plate of the main chassis portion removed, Figure 3 is a side view showing one of the lever arms and its connections to the main chassis portion and one of the guide members, Figure 4 is a plan view of the actuator, and Figure 5 is a sectional side view of the actuator.

Referring now to the drawings, the lifting hoist shown therein comprises a mobile chassis 10, and a lifting column 11 upstanding from the chassis 10. The hoist could also include a lifting arm which can be raised and lowered along the lifting column, a sling hanger support swivellable about a vertical axis at the free end of the lifting arm, and a sling hanger pivotable about a horizontal axis with respect to the sling hanger support The chassis comprises a main portion 12 and two side members 13 which project forwardly from opposite sides of the main portion 12 in parallel spaced relationship. The side members 13 are secured at their rear ends to respective guide members 14 which extend perpendicularly to the longitudinal extent of the side members 13.The guide members 14 are of tubular construction and are coaxially supported within the main chassis portion 12 by sleeve bearings 15 for slidable movement relative to the main chassis portion 12.

Two lever arms 16 are connected between the main chassis portion 12 and respective guide members 14.

The two lever arms 16 are arranged on opposite sides of the lifting column 11 for swivellable movement in a horizontal plane. The rear ends of the lever arms 16 are pivotably connected to a beam 17 forming part of the main chassis portion 12 by pivot pins 18. The front ends of the lever arms 16 are bifurcated and are pivotably connected to respective guide members 14 by pivot pins 19. The lever arms 16 are arranged to extend forward, that is to be parallel to the chassis side members 13, when the side members 13 are substantially midway between innermost and outermost positions.

The lever arms 16 are pivoted by power operated means comprising an electric motor 20 and an actuator 21 having twin screws 22 extendible or retractable simultaneously and in opposite directions upon rotation of an outer sleeve 23 supporting two nuts 24 which co-operate respectively with the two screws 22.

The actuator 21 extends transversely of the chassis and the sleeve 23 is journalled in bearings 25 supported by part of the main chassis portion 12. The sleeve 23 is connected to the motor 20 by a chain drive or belt 26.

The guide members 14, lever arms 16, actuator 21 and motor 20 are covered by a top plate 27.

When the motor 20 is rotated in one direction, the twin screws 22 are extended in opposite directions and these screws 22 in turn pivot the two lever arms 16 in opposite directions. The lever arms 16 extend the two guide members 14 in opposite directions and these in turn extend the side members 13 of the chassis while maintaining the side members 13 in parallel relationship. Rotation of the motor 19 in the opposite direction will have the opposite effect and will retract the side members 13 to provide a minimum width for use of the hoist in confined spaces and for passing through doorways.

The motor 20 is powered by a rechargeable battery (not shown) and operated by a foot operated switch 28 or a remote control handset.

The embodiment described above is given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the present invention. For example, the chassis described above could be used with other types of invalid hoist. Also the actuator 21 could be replaced by two endless chains which are each mounted about transversely spaced sprockets, one of which is driven by the motor 20, the chains being connected, respectively, intermediate their ends to the two lever arms 16.

Claims

1. A mobile invalid hoist having a lifting arm projecting from an upstanding support structure or column mounted on a chassis, wherein the chassis comprises a main portion supporting the support structure or column, and two chassis side members which project forwardly from the main portion in parallel spaced relationship, the side members being connected to respective guide members which extend transversely of the longitudinal extent of the side members and which are supported by the main chassis portion for slidable movement relative thereto, a pair of lever arms each of which is pivotably connected at one end to the main chassis portion and which are pivotably connected at their other ends to the two guide members, respectively, and means for pivoting the two lever arms simultaneously to effect simultaneous movement of the side members away from or towards the main chassis portion, the side members remaining in parallel spaced relationship over the extend of their movement.

2. A mobile invalid hoist as claimed in claim 1, wherein the pivoting means is power operated.

3. A mobile invalid hoist as claimed in claim 2, wherein the pivoting means comprises screw-threaded actuator means extended and retracted by an electric motor.

4. A mobile invalid hoist as claimed in any one of the preceding claims, wherein the lever arms extend in a direction parallel to the side members when the side members are substantially mid-way between outermost and innermost positions.

5. A mobile invalid hoist as claimed in any one of the preceding claims, wherein the guide members and lever arms are below a top plate of the main chassis portion.

6. A mobile invalid hoist as claimed in any one of the preceding claims, wherein the main chassis portion is provided with two ground-engaging support castors and each side member is provided with a ground-engaging support castor at or adjacent to its front end.

7. A mobile invalid hoist substantially as hereinbefore described. with reference to the accompanying drawings.