GB2189219A

GB2189219A - Invalid hoists

Info

Publication number: GB2189219A
Application number: GB08704638A
Authority: GB
Inventors: David Richard James
Original assignee: James Industries Ltd
Current assignee: James Industries Ltd
Priority date: 1986-04-15
Filing date: 1987-02-27
Publication date: 1987-10-21
Also published as: IT1207386B; GB8704638D0; AU6922887A; GB8609100D0; IT8767298A0; DK155487A; SE8700881D0; SE8700881L; AU585130B2; CH671152A5; FR2596981A1; GB2189219B; DK155487D0; JPH0341182B2; DE3709184A1; BE1001354A4; DK161735C; FR2596981B1; NL8700899A; NL189233C

Abstract

An invalid hoist has a lifting arm 3 mounted at the inner end thereof on a support structure or column 1 of the hoist. The arm 3 is secured at the outer end to the housing 13 of a vertical bearing for the support of an invalid support member. The arm 23 comprises two links 9, 10 of a parallelogram linkage, one of these links 9 being disposed within a central space within the other link 10 of the linkage. <IMAGE>

Description

SPECIFICATION Invalid hoists The invention relates to invalid hoists of the type comprising a lifting arm which undergoes angular lifting movement relatively to a support structure or column from which the arm projects. It is concerned with hoists of this type with means for the attachment of a patient support member mounted at the outer end of the arm so as to pivot about a rigid vertical bearing, that is to say a bearing the axis of which remains substantially vertical throughout the full range of angular movement of the arm.

In order to maintain the vertical orientation of said bearing it is known for the arm to be of parallelogram form with two vertically spaced links mounted on fixed pivots at the inner end and pivotally attached to the bearing housing at the outer end. It will be appreciated that the spacing between the links changes during angular movement of the arm and to maintain a spacing such that there is no danger of the fingers of the invalid being lifted or of an attendant becoming trapped it is necessary to have a considerable spacing when the arm is in either of the extreme upper and lower positions. This results in a cumbersome construction with the end pivot points being disposed at the minimum link spacing dictated by the needs of safety.

Furthermore, both links have to be of considerable cross-section to avoid accidental damage as compared with the mechanical longitudinal strength required and this further contributes to a massive appearance and to the weight of the hoist.

The object of the invention is to provide a hoist with a safe and compact arm construction which is of neat appearance and of lighter weight than equivalent prior constructions.

According to the invention an invalid hoist has a lifting arm mounted at the inner end thereof on a support structure or column of the hoist, and secured at the outer end to the housing of a vertical bearing for the support of an invalid support member, said arm comprising two links of a parallelogram linkage with one of the links disposed within a space within the other link.

Preferably the said one link is a relatively small section rod of circular or rectangular cross-section connected between upper pivots of the linkage so that it operates in tension, and said other link which is in compression may be of hollow box-section so that said one link is completely enclosed therein. Although this is the preferred construction said other link may alternatively comprise horizontally spaced link elements separated by said central space within which said one link is disposed.

The inner and outer end pivots of the parallelogram linkage may be provided on circular bosses respectively secured to the support structure or column and to the housing of said vertical bearing. Said one tensioned link is then preferably disposed in an upper region of the space within the other link with the end pivots of the latter disposed centrally of said circular bosses. The inner end central pivot may be provided by a central portion of a stepped handle which projects laterally and horizontally to provide handgrips at each side of the support structure or column for use by an operator in order to propel and manoeuvre the hoist when the latter incorporates a mobile chassis.

A lifting mechanism associated with the support structure or column may adjustably support the arm through an extendable or movable strut which is connected to said other link. When this link is of hollow boxsection the bottom wall thereof may be cutaway to provide clearance for the said strut with the upper end of the latter attached, within the box-section link, by a pivot extending between the side walls of the box-section.

Alternatively, the upper pivot of the strut may be provided by a pivot bracket secured to the lower side of said other link externally thereof.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, a mobile invalid hoist embodying the invention and a modification thereof. In the drawings: Figure 1 is a general perspective view of the hoist; Figure 2 is a partly cut-away and sectioned detail view illustrating the construction of a lifting arm of the hoist; and Figure 3 is a detail view illustrating the modification.

The hoist comprises an upstanding and slightly rearwardly inclined column 1 mounted on a mobile chassis 2. A lifting arm 3 which undergoes angular lifting movement relatively to the column 1 projects from the latter and is adjustably supported by a strut 4. The lower end of the strut 4 is pivotally attached at 5 to a lifting mechanism housed within the column 1 and which comprises a traveller 6 movable along the column and projecting through a longitudinal slot 7 in the column 1 for attachment to the strut 4. Movement of the traveller 6 along the column 1 and corresponding movement of the lifting arm 3 is controlled by a winding handle 8 mounted at the top of the column 1.

The arm 3 is of parallelogram type and comprises two links 9 and 10 pivotally attached at the inner end to a circular boss 11 welded to the column 1 and pivotally attached at the outer end to a circular boss 12. The boss 12 is welded to the housing 13 of a vertical bearing supporting a patient support member 14 to which various sling lifting arrangements (not shown) can be attached. Due to the parallelogram form of the lifting arm 3 the axis A of the bearing remains substantially vertical throughout the full range of angular movement of the arm 3, the lower and upper limits of such movement being respectively illustrated, in ghost outline, at 3a and 3b.

One of the arm links 9 is a relatively small diameter steel rod, whereas the other link 10 is a fabrication mainly of hollow box-section steel construction, and the link 9 is disposed within an upper region of the central space provided by the rectangular box-section of the link 10. Thus the link 9 is concealed within the link 10, contributing to a neat and compact appearance, and is protected against accidental damage so that it need only be of the cross-section necessary to withstand operating tensile forces. The bottom wall 10a of the link 10 is cut-away at 15 to provide clearance for the strut 4 which has an upper end boss 16 which turns on a pivot 17 extending between the side walls lOb of the link 10.

The circular bosses 11 and 12 are cut-away to receive inner and outer ends 18 and 19 of the link 9 through which pivot pins 20 and 21, mounted respectively at an upper level in the bosses 11 and 12, extend for pivotal attachment of the link 9. The link fabrication 10 includes inner end circular discs 22 of the same diameter as the boss 11 and which locate laterally against that boss which is disposed between them. Circular discs 23 at the outer end of the link 10 are similarly associated with the boss 12, and the two end pivots of the link 10 are respectively disposed centrally of the bosses 11 and 12.

The inner end pivot of the link 10 is provided by a handle 24 comprising a side member 25 which screws on to an opposite side handle member 26, the latter being stepped to provide a reduced diameter section 26a passing coaxially through the boss 11 and the discs 22 to provide the inner end pivot for the link 10. The outer end pivot of this link is provided by a pivot bolt 27 passing coaxially through the boss 12 and discs 23. Moulded plastics handgrips such as 28 are fitted, respectively, over the ends of the handle members 25 and 26.

In the modification of Figure 3, the boxsection link 10 is as shown cranked in side view. To allow clearance for the link 9 within the link 10 the upper pivot 17 of the strut 4 is moved externally of the link 10. This pivot 17 is now provided on a pivot bracket 29 welded to the bottom wail 10a of the link 10, below the latter. This modification also avoids any disadvantage which might be attendant on providing the cut-away section 15 of the bottom wall 10a, and thus the external pivot bracket 29 could if desired be used with a straight arm 3 as in Figures 1 and 2.

In Figure 3 the upper end of an invalid support member 30 which in this case is a support sling hanger, is shown supported in the vertical bearing at the outer end of the arm 10.

Claims

1. An invalid hoist having a lifting arm mounted at the inner end thereof on a support structure or column of the hoist, and secured at the outer end to the housing of a vertical bearing for the support of an invalid support member, said arm comprising two links of a parallelogram linkage with one of the links disposed within a space within the other link.

2. An invalid hoist according to claim 1, wherein said one link is of relatively small cross-section and is connected between upper end pivots of the linkage so that it operates in tension.

3. An invalid hoist according to claim 1 or claim 2, wherein said other link is of hollow box-section so that said one link is completely enclosed therein.

4. An invalid hoist according to claim 1 or claim 2, wherein said other link comprises two horizontally spaced link elements separated by said space within which said one link is disposed.

5. An invalid hoist according to any one of the preceding claims, wherein inner and outer end pivots of the linkage are provided on circular bosses respectively secured to the support structure or column of the hoist and to said bearing housing.

6. An invalid hoist according to claim 5, wherein the end pivots of said other link are respectively disposed centrally of said circular bosses.

7. An invalid hoist according to claim 6, wherein the inner end pivot of said other link, disposed centrally of the circular boss secured to the support structure or column, is provided by a central portion of a stepped handle which projects laterally and horizontally to provide handgrips at each side of the support structure or column.

8. An invalid hoist according to any one of the preceding claims, wherein a lifting mechanism associated with the support structure or column adjustably supports the arm through an extendable or movable strut pivotally attached, at the upper end, to the parallelogram linkage.

9. An invalid hoist according to claims 3 and 8, wherein a bottom wall of said other link is cut-away to provide clearance for said strut with the upper end of the latter attached, within said other link, by a pivot extending between side walls of said other link.

10. An invalid hoist according to claims 3 and 8, wherein said strut is attached to said linkage at a pivot bracket secured to said other link below the latter.

11. An invalid hoist according to any one of claims 8 to 10, wherein said support structure or column comprises a column of hollow boxsection and said lifting mechanism comprises a traveller movable along the column and to which the lower end of said strut is pivotally attached.

12. An invalid hoist constructed and arranged substantially as herein particularly described with reference to Figures 1 and 2, or Figure 3, of the accompanying drawings.