WO1993006810A1

WO1993006810A1 - Patient lifting device

Info

Publication number: WO1993006810A1
Application number: PCT/AU1992/000527
Authority: WO
Inventors: Kenneth William Miles
Original assignee: Miles Kenneth W
Priority date: 1991-10-03
Filing date: 1992-10-03
Publication date: 1993-04-15
Also published as: GB2275665B; GB2275665A; GB9406595D0

Abstract

A hoist assembly (33) for a physically handicapped person comprising an electric motor (8), gearing means (5, 6) coupling the electric motor (8) to a drum for reeling a load suspension cable, guide means for restricting lateral movement of the load suspension cable, and securement means (21) for attachment of support straps for suspending of said person from said hoist assembly.

Description

TITLE: PATIENT LIFTING DEVICE

FIELD OF THE INVENTION:

This invention relates to a hoist assembly for physically handicapped persons and in particular to an assembly^■which is self-contained and can be totally operated by that person.

BACKGROUND TO THE INVENTION:

While apparatus exists for the lifting of physically handicapped persons, those apparatus are intended to be operated by an assistant. As those apparatus are also large and cumbersome, the assistant is also required to relocate the apparatus to reposition the hoisted person. Consequently, a physically handicapped person is not able to easily move around a room or develop any sense of autonomy.

It is also desirable in lifting persons to provide apparatus which is compact in size, stable in use and inexpensive to produce.

SUMMARY OF THE INVENTION:

The present invention provides

a hoist assembly for a physically handicapped person comprising an electric motor,

a gearing means coupling the electric motor to a drum for reeling a load suspension cable,

guide means connected to said assembly for restricting lateral movement of said load suspension cable with respect to said hoist assembly, and securement means for attachment of support straps, for suspending of said person from said hoist assembly.

PREFERRED FEATURES OF THE INVENTION:

Preferably said _. load suspension cable is slideably connectable to a carrier track for supported movement of said person.

In a preferred form the drive means is coupled to said gear means by an epicyclic gearbox. The gearing means preferably comprises a worm gear which is connected to the drum.

Preferably the guide means comprises two sets of parallel rollers arranged at right angles to each other with sufficient clearance for the suspension cable.

Furthermore, the securement means of the assembly may comprise an upper support bar with upper support hooks at the ends thereof and a lower support bar with lower support hooks at each of its ends.

In one instance the hoist assembly comprises a housing enclosing the drum and wherein the drum is located in a lowermost portion of the housing and the guide means is located at an uppermost portion of the housing.

Preferably the electric motor, a battery therefor, and the gearing means are located to a side of the housing opposite to the drum to at least in part counter-balance the hoist assembly and the load thereon in use.

Preferably the drum is supported at one end adjacent said side and is unsupported at the other end.

Preferably the electric motor has a no load speed in excess of 2500 revs per minute and the gearing means has a reduction ratio of not less than 250:1.

Preferably the cable is a braided rope and the drum has a diameter of not greater than 7 times the diameter of the rope.

Preferably there is a switch which, when operated in one manner, will cause paying out of the cable, when operated in another manner will cause reeling in of the cable and wherein the switch is biased to normally take up an off condition.

Preferably there is a pendant cable and a switch attached thereto whereby the hoist assembly can be operated remotely therefro .

Preferably there is a coupling and a hand operable turning device adapted to be engaged with the coupling to pay out or reel in the cable manually.

Preferably the electric motor is floatingly coupled to the gearing means and torque resisting means is associated with the motor and can abut against the housing to restrict the motor against rotation.

A specific embodiment of a hoist assembly in accordance with this invention will now be described by way of non- limiting example with reference to the accompanying drawings.

DESCRIPTION OF THE VIEWS OF THE DRAWINGS:

Figure 1 is a sectional front elevation of the embodiment of the present invention;

Figure 2 is a sectional side elevation of the embodiment shown in Figure 1, and

Figure 3 is a schematic diagram illustrating a use of the embodiment of the invention.

41. Casing Part

42. Casing Part

43. Buffer 51. End 52. Hole

DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS:

Referring to Figure 1, the hoist assembly 33, comprises a main body plate 1 connected to top and bottom support bars 2 and 3. Mounted on one side 30 of the body plate 1 is an electric motor 8 and a battery powerpack 9 for powering the motor. The electric motor 8 is coupled through an epicyclic gearbox 31 which provides about a 10:1 reduction to a gearing means within a gearbox housing 4.

The gearing means comprises a worm drive 6 which engages a tooth gear 5. This provides a reduction of about 30:1.

Gear 5 shares a common axle 37 with a suspension drum 12. The drum is located on the side 35 of the plate 1. Reeled onto drum 12 is a load suspension cable 14 which extends upwardly alongside and beyond plate 1. The cable 14 passes between two sets of parallel guide rollers 13 which are arranged at right angles to each other and restrict lateral movement of the cable relative to the hoist assembly.

Suspension cable 14 has a loop 15 at its extremity which allows the hoist assembly 33 to be connected to a carriage 24 on a carrier track 25.

Control switch 10 is provided to activate and deactivate electric motor 8 to turn in a selected direction.

The motor 8 and gearbox 31 are free floating but are held in place against rotation by torque plate 7 which can abut against the plate 1 or an abutment 34. As the electric motor can be driven in both directions, the drum 12 is capable of rotating in either direction to reel out or reel in the suspension cable 14.

To raise a physically handicapped person, a support strap 20 is placed under the thighs of the patient. The straps 20 which have a metal loop connected at each end are attached to the lower support bar 2 by slipping the metal loops over hooks 21. Similarly, an upper support strap 22 which has metal loops (not shown) attached at each end is slipped under the armpits and around the back of the person. The metal loops are then slipped over hooks 23 formed on the upper support bar 3.

The loop 15 formed at the end of load support cable 14 is removably connected to a carriage 24 which slides within a carrier track 25.

The carrier track 25 is substantially a C-shaped channel and is mounted to a ceiling or other overhead means. The carriage 24 which is provided with a roller (not shown) is permitted to slide freely in a longitudinal direction but prevented by a flange (not shown) on the channel from being removed from the channel.

For a person to move themselves using the hoist assembly 33 of the present invention, the person positions the support straps 20 and 22 and connects the straps to the upper and lower support bars 2 and 3. The electric motor 8 is then activated and the suspension cable is reeled onto drum 12. Once the person is suspended at a manageable height, the person can move the carriage along the track while they are suspended by swinging their weight in a direction substantially in line with the carrier track.

Alternatively, a closed loop transfer rope 26 can be attached to the hoist assembly 33 and threaded through pulleys 27 at either end of the carrier track 25. Therefore, once the person is suspended by the hoist assembly, they can move themselves along in the direction of the carrier track by pulling on the rope.

The cable 14 is desirably a braided rope as such braided ropes may be wound on small drums without substantial likelihood of damage. It is to be noted that a ratio of drum diameter to rope diameter of less than 7:1 is possible as compared to 13:1 if wire rope is used as wire rope cannot be wound upon a small drum without likelihood of damage. Thus, using 6 mm diameter braided rope I have been able to reduce the diameter of the drum to less than 40 mm and this has helped making the hoist assembly of a reasonable size enabling it to be easily transported from one transfer station to another. A total weight of 8 kg or less has been achieved.

Further, the drum 12 is located adjacent the bottom 36 of the plate 1 and the guide rollers 13 are located adjacent the top of the plate 1 and this maximum separation of the drum 12 and rollers 13 allows the rollers 13 substantial leverage in bringing the user to a sitting position. In this respect the bars 3 are located at substantially the same level as the rollers 13 and this means that the user will stably sit with respect to the hoist assembly 33.

Still further, the drum 12 will be located adjacent but slightly above the centre of gravity of the person to be lifted and this will promote stability. In general, applicant has found it best if the drum 12 is located below shoulder height and above waist height.

The plate 1 will separate the cable 14 from the gearboxes 31 and 4 and thus fouling by any escaped grease is unlikely. As stated, the drum 12 is mounted on the axle 37 and this mounting is at the end 38 of the drum 12. At the opposite end 39 the drum is unsupported and this allows a reduction of the amount of projection of the casing part 41 from the side 35 of the plate 1 with an overall reduction of the size of the hoist assembly 33.

The end 39 of the drum 12 is hollow and open and the drum 12 has a hole through which the end of the cable 14 passes into the hollow where it is knotted or otherwise dealt with to secure it to the drum 12.

Thus, replacement of cable 14 can be done by removing casing part 41 but this will not involve access to the parts on the side 30 of the plate 1 which will continue to be covered by casing part 42.

The cable 14 preferably has a breaking strain in excess of 1 tonne with more than 1.5 tonne being more pref rred.

The battery 9 is preferably able to be removed for charging purposes or for replacement by another charged battery.

The motor 8 and gearbox 31 are free floating and this avoids mounting means which would increase costs and also results in a self-aligning tendency.

To prevent the motor 8 and gearbox 31 rotating more than a few degrees, a torque plate or rod 7 can abut against the plate 1 or an abutment 34. To prevent annoying noise, the plate or rod 7 preferably has a rubber or elastomeric buffer 43 at its end.

The motor 8 is a readily available lightweight 12 volt motor which will turn at about 3600 rpm with no load.

The gearbox 31 is also readily available and is an about SUBSTITUTESHEET 10 : 1 reduction.

The output from the gearbox 31 is about 200 kg/cm torque at about 350 rpm.

The worm 6 is mounted on a shaft having a squared end 51 and a hole 52 is provided in the housing part 42. A hand operated turning device, such as a socket wrench can have the socket thereof entered into the hole 52 to engage the end 51 and thus turn the drum 12 by hand. This may be necessary in the case of a flat battery.

Instead of mounting the hoist assembly 3 to the rail 25 it can be mounted instead to any convenient object such as a frame around a bed, a movable tripod, a frame above or besides a bath or swimming pool.

The switch 10 can be replaced or in addition there maybe by a pendant cable with a switch to allow for remote operation such as by a carer. A pluggable into socket for such a pendant cable may be provided.

The above described hoist assembly is cheap and easily manufactured, it is compact and simple to use even by those having little strength or manual dexterity.

Using the hoist assembly enables transfer of a person into and out of beds, wheel chairs, baths, swimming pools and other places.

The hoist assembly is strong and stable.

The parts used to construct the hoist assembly are cheap and readily obtainable.

Since only battery power is used, the hoist assembly can be used in wet environments.

Since modifications within the spirit and scope of the invention may be readily effected by persons skilled in the art, it is to be understood that the invention is not limited to the particular embodiment described, by way of example, hereinabove.

The claims and drawings form part of the disclosure of the specification.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A hoist assembly for a physically handicapped person comprising

an electric motor,

gearing means coupling the electric motor to a drum for reeling a load suspension cable,

guide means for restricting lateral movement of the load suspension cable, and

securement means for attachment of support straps for suspending of said person from said hoist assembly.

2. A hoist assembly as claimed in Claim 1, and further comprising

a housing enclosing the drum and wherein the drum is located in a lowermost portion of the housing and the guide means is located at an uppermost portion of the housing.

3. A hoist assembly as claimed in Claim 2, wherein the electric motor, a battery therefor and the gearing means are located to a side of the housing opposite to the drum to at least in part counter-balance the hoist assembly and the load thereon in use.

4. A hoist assembly as claimed in Claim 3, wherein the drum is supported at one end adjacent said side and is unsupported at the other end.

5. A hoist assembly as claimed in any preceding claim, wherein the electric motor has a no load speed in excess of 2500 revs per minute, the gearing means has a reduction ratio of not less than 250:1.

6. A hoist assembly as claimed in any preceding claim, wherein the cable is a braided rope and the drum has a diameter of not greater than 7 times the diameter of the rope.

7. A hoist assembly as claimed in any preceding claim, including a switch which, when operated in one manner will cause paying out of the cable, when operated in another manner will cause reeling in of the cable and wherein the switch is biased to normally take up an off condition.

8. A hoist assembly as claimed in any preceding claim including a pendant cable and a switch attached thereto whereby the hoist assembly can be operated remotely therefrom.

9. A hoist assembly as claimed in any preceding claim including a coupling and a hand operable turning device adapted to be engaged with the coupling to pay out or reel in the cable manually.

10. A hoist assembly as claimed in any preceding claim wherein the electric motor is floatingly coupled to the gearing means and torque resisting means is associated with the motor and can abut against the housing to restrict the motor against rotation.