GB2338226A - Invalid lifting device - Google Patents

Abstract

A lifting device for a person, comprising a base (10); a lifting column (11) extending upwardly from the base, said lifting column comprising a first column part (12) fixed to the base to extend upwardly therefrom, and a second column part (13) telescopically movable relative to the first column part; said second column part carrying person-support means; winding means (14) carried by said second column part; and an elongate flexible tension element (96) extending from said winding means downwardly to guide means at a lower part of said second column and thence upwardly to an anchorage point (68) on said first column part, said tension element being windable by said winding means for causing said movement of the second column part relative to the first column part. Preferably said elongate flexible tension element comprises a woven tape or ribbon and the winding means comprises an electrically operable winch with reduction gearing between said motor and the winding drum. Preferably said second column 13 is guided for telescopic movement within said first column via guide surfaces and rollers mounted on both columns.

Description

2338226 Title: LIFTING DEVICE

Description of Invention

This invention relates to a lifting device for a person. A person might require to be lifted by a device in accordance with the invention for reasons of physical infirmity, for example due to age, illness or injury, or for some other reason.

There are many situations where persons who are not physically fully able require assistance in attending to their physical needs. For example, a person who is unable or substantially unable to walk and therefore makes use of a wheelchair for mobility has to transfer between the wheelchair and his or her bed, and similarly between a wheelchair and a toilet, and so on. Such actions frequently require the person to be lifted and while this can be done by attendants it is not desirable because of inconvenience and the risk of injury to the attendants themselves through liftin- what mi-lit be a very heavy weight. Therefore a lifting device for the purpose is a desirable th1110 There have been various proposals and known lifting devices for such purposes. Many have utilised fluid-pressure operated piston and cylinder rani devices as the means which causes a lifting action to take place, and this renders such lifting devices cornplex and expensive. It is broadly the object of the present invention to provide a lifting device improved by virtue of simplicity in construction, econoinical manufacture, and like beneficial aspects.

According to the present invention, we provide a lifting device for a person, comprising a base; a liftiii(, colurnn extending upwardly fi-om the base. said lifting column comprising a first colunin pail fixed to the base to extend upwardly therefi.orn, and a second colunin pail telescoplcally illovable relative to the first colurrin pail. said second colunin pail cai-i-yiii('., person-support 1 2 means; winding means carried by said second column part; and an elongate flexible tension element extending from said winding means downwardly to guide means at a lower part of said second column pail and thence upwardly to an anchorage point on said first column part, said tension element being windable by said winding means for causing said movement of the second column part relative to the first column pail.

Preferably said elongate flexible tension element comprises a woven tape or ribbon (i.e. an element which in cross-sectional shape is relatively wide and thin) of a fibrous material,. It may be woven of a yarn of a polyester or other suitable material.

Said elonaate flexible tension element preferably lies at least partially in recess means extending lengthwise of said second column pail oil the exterior thereof This facilitates a simple mechanical an-angement of the tension element and guide means therefor, whilst rendering it less vulnerable to accidental damage.

Said second column part is preferably guided for its telescopic movement relative to the first column pail by guide means operable between said column parts and including roller means.

Said winding means preferably comprises ail electrically operable winch carried by a winding head at the upper end of the second column part. Such a winch will normally comprise one or more sta(,es of reduction gearing providing a high reduction ratio between ail electric rnotor and a windino drum on which the tension element is an-anged to be wound.

The person-support means conveniently comprises a seat whicli preferably is carried by and extends downwardly from said winding head.

A liftina device utillsina ail cloii,,ate flexible tension element arranoed in C1 0 ZY 0 accordance with the invention has the advantage of simplicity and economy of construction compared with devices utilising hydraulic rams or the like as the means by which lifting is effected. A flexible tension element arranged in 0 0 1 3 accordance with the invention itself provides a mechanical advantage in that the winding of a certain length of the element by the winding means produces a vertical movement of the second column pail relative to the first column part of only half the amount of winding. Accordingly loads in the flexible tension element are kept low, whilst the winding means can comprise a relatively simple design of winch.

The base of the lifting device is preferably provided with wheels and/or castors or the like whereby the device, with a person carried thereby, may be moved over a floor surface. For safety, braking means operable as required may be provided.

It will be appreciated that the person-support means may alternatively comprise a sling or other known supporting device, as appropriate for the intended use.

The invention will now be described by way of example with reference to the accompanying drawings, of which:- Figure 1 is a partly sectioned side elevation of a lifting device in accordance with the invention, and Figure I A illustrates the arrangement of the flexible tension element thereof, Figure 2 is a horizontal section on the line 2-2 of Figure 1; Fiaure 3 is a horizontal section on the line 3-3 of Figure 1.

Figure 4 is a plan view, partly sectioned, of the winding head of the 0 device; Figures 5 and 6 are rear and side views, partly sectioned, of the winding head of the device.

RefelTing firstly to Figure 1 of the drawincos, the illustrated lifting device comprises a base 10, and a liftling colunin indicated generally at 11, and comprising a first pail 12 wliicli is secured to the base and a second pail 1 -3) which is telescopically assembled with the first pail and is movable upwardly, and downwardly relative to the latter. At the top of the second pail 13 there is 1 4 a winding head 14 in which there is disposed a winding mechanism to be described in greater detail hereafter. The winding head 14 also carries a person-support means 15 which as illustrated is a seat having a backrest part 16 and base cushion 17. The scat base 17 may be adapted to be used, when required, with a commode pan assembly indicated generally at 18. The seat and its associated parts will riot be described in greater detail herein.

The base 10 has a cast aluminium chassis 20 with reinforcing ribs 21 therebeneath. It has front castors 22 and rear castors 23), the latter being provided with brakes. At a rear part of the chassis 20 the first pail of the liftincy column 12 is fixed to extend upwardly from the chassis. A housing 24 behind the column pail 12 accommodates a battery pack for providing electrical power to operate the winding motor as described hereafter: the battery pack and its housing are preferably completely removable for charging/replacement purposes and have an electrical connection established with them when they are fitted by way of an appropriately configured plug and socket arrangement.

The first, outer, pail 12 of the lifting column 11 has its crosssectional shape shown rnost clearly in Figure 3). It is an extrusion of a suitable aluminium alloy and is generally rectangular in cross-sectional shape with opposed parallel walls 30, 31 and opposed walls 32, 333 which are outwardly convex and a mirror image of one another. The crosssectional shape includes a number of pail-circular formations one of which is indicated at 34. At the lowermost end of the column pail 12 these formations are screw-threaded to be engaged by fixing bolts extending upwardly through the chassis as indicated at '35 in Figure 1, thereby to secure the column pail to the chassis. The front and rear walls 32, 33 of the colunin pail 12 have inwardly extending guide formations '36 which end in flat surface facin. the second inner, column pail 13) whose cross-sectional shape is also clearly seen in Figure 3). The walls 30, 31 of the column pail 12 have opposed inwardly facing flat guide surfaces 37.

0 The cross-sectional shape of the second, inner, column pail 13 is shown clearly in Figures 2 and 3. Externally it is substantially square with rounded corners, and externally its fi-ont and rear walls 40, 41 have shallow outwardly facing recesses 42, 43 respectively therein. Internally, the column part 13 has inwardly extending projections in which are defined undercut recesses 44, 45 at each side of the column part. At the sides of the lowermost end of the column part 13, forwardly and rearwardly extending mounting plates 46, 47 are secured and between them these carry a pair of rollers 48, 49 arranged with the roller 48 above the roller 49 and both rollers engaging the fiat end surfaces of the guide formations 36 extending inwardly frorn the wall 32 of the outer column member 12. At the rear of the column pail 13, upper and lower rollers 50, 51 are similarly carried by the plates 46, 47 and engage the guide surfaces of the formations 36 extendinu Inwardly frorn the rear wall 33 of the column pall 12. Guide pads 52, 53) oil the outside of the plate 47 engage the surfaces J37 of side wall 30 of the column pail 12 for sliding movement in the upwards and downwards direction, whilst guide pads 54, 55 on the outside of the plate 46 similarly engage the surfaces 37 of the wall 3) 1 of the column pail 12. Thus the lowermost end of the column pail 13 I's guided foi- upwards and downwards movement within tile column pail 12.

Further supported within the lowernlost pail of the colunin pail 13 are two guide rollers 52, 53) whose external surface includes a poillon of reduced diameter as indicated at 54. The extent of portion 54 in the direction of the rotational axis of each roller is substantially the sanle as the extent of the recesses 42, 43 in the outside surface of the column pail. The diameter of eacli roller portion 54 is such that the surface of the portion 54 lies substantially, flush with the innerniost surface of each recess 42, 43, At the top of the outer pail 12 of the lifting column 11 the column pail 13) is guided by the arrangement shown most clearly in Figure 2. The column pail 12 carries a top yoke 60, secured to the column pail by, bolts extendill(l c 6 downwardly through apertures 61 in the top yoke into respective ones of the pail-circular folmiations 34 of the column pail which are screw- threaded in the same way as they are screwthreaded at the lowermost end of the column part. Two of such fixing bolts are visible at 62 in Figure 1.

The top yoke 60 is provided internally with two opposed mounting plates 63 and these carry between them upper and lower front rollers 64, 65 and an upper rear roller 66. Beneath the upper rear roller 66 there are two short rollers 67 one at each side, and between them a tape anchor member 68. The mounting plates 63 further carry top-li at-sh aped guide members 69 which are engaged by adjuster screws as indicated at 70 and in turn have sliding engagement with oppositely outwardly facing side surfaces of the inner column part 13, as indicated at 71. It will thus be appreciated that the inner part 13 of the lifting column is guided and closely constrained for telescopic upwards and downwards movement relative to the outer part 12. Such guidance is effected primarily by rollers at the front and rear of the lifting column, and sliding guide members at the sides of the liftincolumn.

The top yoke 60 has a handle assembly 75 whereby an attendant is able to propel and guide the lifting device around when the brakes on the castors thereof are released.

The winding head at the upper end of the second column part 13) '15 shown in greater detail in Figures 4 to 6. Two mounting plates 80, 81 are secured at respective sides of the column part 13) by fasteners as indicated at 82 extending through apertures in the mounting plates and in the column pail 13) to engage nuts held captive in the formations 44, 45 at the interior of the column pail. The mounting plates 80, 8 1 extend forwardly from the top of the column pail 13).

Between the plates 80, 81 there is supported a winding drum 83. The winding drurn 83) has spaced parallel guide plates 84 and is carried on a shaft 85 which is supported in the plates 80, 81 by ball-bearing assemblies 86. Fast 7 with the drum 83 on the shaft 85 is a relatively large diameter drive gear 87. Outside the plate 81, the shaft 85 carries an inertia safety brake 88 which comes into operation if the rotational speed of the drum 83 and shaft 85 exceeds a predetermined safe limit.

The inertia safety brake comprises a hub 89 fitted on the shaft 85 and carTying two diametrically opposed pivoted cam elements 89a with portions which are able to extend radially outwardly from the hub when they are appropriately pivoted. In normal slow speed rotation of the shaft the cam elements pivot under the influence of gravity, to extend and retract the portions thereof. When the shaft rotates more quickly, the portions of the cam elements do not have time to retract and engage a stop member fixed adjacent the periphery of the hub, causing the hub to be stopped within half a revolution.

Outside the plate 80 there is mounted ail electric motor 90 which has an output shaft extending parallel to the plate 80 and driving, through a worm and worm wheel reduction gearing (indicated generally at 91), a drive gear 92 which meshes with the gear 87. It will be noted that the gear 92 is very much smaller than the gear 87 and this in combination with the worin and worm wheel drive aforesaid provides a two-stage reduction gearing of high reduction 0 0 0 ratio between the electric inotor 90 and the winding druill 83). This ratio of reduction gearing, together with the characteristics of the wonil and worm 0 C wheel drive -earina, has tile result that wheil no electrical power is supplied to the electric inotor 90 the windim, drurn 83 is unable to rotate despite the magnitude of the load which is applied to it.

Further between the plates 80, 81 there is supported a tape guide roller 95. An eloil-ate flexible tension element in the forin of a woven tape 96 has one end anchored to the windin- drum 83 and fi-om there extends over the tape guide roller 95 and downwardly at the fi-ont of tile inner column pall 1-3, where it lies in the recess 42 in the front surface of the latter. At the lowermost end of the colunin pail 13), the tape 96 extends around 90' of the periphery of the 8 roller 52 and thence around substantially the same pail of the periphery of the roller 53. From there the tape extends upwardly lying substantially within the recess 43 in the rear face of the column pail 133 until it reaches the tape anchor 68 to which it is secured. The tape is clamped at the winding drum 83 by spaced tape clamps 97.

Figure IA shows the path assumed by the tape 96 between the winding drum 83 and the tape anchor 68. It shows the tape extending at 96a upwardly to the guide roller 95 and then downwardly at 96b to the roller 52. The tape extends horizontally at 96c between the rollers 52, 53) and thence upwardly at 96d to the tape anchor 68.

It will thus be appreciated that when by operation of the electric motor the tape is spirally wound on to the winding drurn 83) the inner column pail 13 is raised relative to the outer column pail 12. The arrangement is such that the windin of a certain length of tape onto the winding drum causes the 9 0 column part 13 to be raised by a distance equal to half the length of wound tape.

The parts of the winding head above described are enclosed within a housing comprising a lower pail 100 and an upper pail 101. A carrier 102 for the seat 15, 16, 17 is supported by the mounting plates 80, 8 1.

The invention thus provides a lifthig device which is relatively simple and economical to construct.

AltliouAi not described in detail above, it will be appreciated that the lifting device will comprise a control means operable by a patient or an attendant to cause lifting and lowering as required. Such a control means will include a switch or switches which causes electrical power to be supplied from the battery pack 24 to the electric motor 90 to cause the latter to operate ill whichever direction is required. Electrical power may be transmitted by a flexible cable disposed within the lifting column 11.

0 9 The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for perforniing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (13)

1. A lifting device for a person, comprising a base; a lifting column extending upwardly from the base, said lifting column comprising a first column part fixed to the base to extend upwardly thereft.om, and a second column part telescopically movable relative to the first column part; said second column pail carrying person-support means; winding means carried by said second column pail; and an elongate flexible tension element extending from said winding means downwardly to guide means at a lower part of said second column pail and thence upwardly to an anchorage point on said first column pail, said tension element being windable by said winding means for causing said movement of the second column pail relative to the first column part.

2. A lifting device according to Claim 1 wherein said flexible tension element comprises a woven tape or ribbon.

3. A liftim, device accordino. to Clalin 1 or Claim 2 wherein said c c flexible tension element lies at least partially in recess means extend1110 lengthwise of said second colunin pail on the exterior thereof.

4. A liftin- device according to any one of the preceding claims 0 c wherein said second colunin pail is guided for movenient relative to the first column pail by guide means operable therebetween and including roller means.

5. A liftina device accordino to any, one of the preceding claims 0 0 wherein said winding ineans is carried by a winding head at the upper end of 0 the second coluirin pall.

1 11

6. A lifting device according to Claim 5 wherein said winding means comprises an electrically operable winch.

7. A lifting device according to Claim 6 wherein said winch comprises reduction gearing of high reduction ratio between an electric motor and a winding drum on which the tension element is arranged to be wound.

8. A lifting device according to Clairn 5 or Claim 6 or Claim 7 wherein said person-suppoil means is carried by said winding head.

9.

A liftin- device accordin- to Claim 8 wherein said person-support 0 0 means comprises a scat extending downwardly from said winding head.

10. A lifting device according to any one of the preceding claims wherein the base is provided with wheels, castors or the like whereby the device may be moved over a floor surface.

A liftino device accordim, to Claiin 10 further comprising braking 0 c 0 0 means.

12. A liftino. device substantially, as liereinbefore described with C) 1 reference to the accompanying drawings.

13. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

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