Patent Application
20200337921
The present invention relates to device for bearing the weight of a load. One or more embodiments have application to facilitating raising, lifting and/or carrying the load. Methods for providing the device and for using the device are also described herein.
Hoisting devices have widespread use in hospitals, aged care facilities and private settings for facilitating the raising or lifting of person(s). Such hoisting devices can be mounted overhead to support frames, to a ceiling fixture, or to track systems secured to the ceiling for the hoist for being rolled along the track on rollers of the hoisting device. Hoisting devices are, for instance, disclosed in International Application Publication No. WO 2005/041838. These hoisting devices comprise an electrically operated hoist module for connection to a trolley mounted on an overhead track. The trolley has rollers for allowing the trolley to be rolled along the track, and the hoist module is first connected to the trolley via a wire cable. The hoist module is then raised to the trolley by either operation of a reel of the module to wind up the wire cable whereby the module is drawn up the wire cable or in another form, it appears the wire cable is wound onto a manual reel and the module pulled up to the trolley. A strap hangs from the hoist module to which a lifting bracket is coupled. The strap can be drawn up or lowered by the hoisting module to raise or lift the lifting bracket. In use, a sling or the like for fitting about a person can be carried by the lifting bracket.
In an aspect of the invention there is provided a weight bearing device for being located overhead to support the weight of a load applied to the device in use, the device comprising:
a reel for winding up or unwinding a support belt for supporting the load, the reel being rotatable about a first axis of rotation;
a locking mechanism for locking the reel against rotation about the first axis of rotation and thereby unwinding of the support belt; and
an actuator element for being driven about a second axis of rotation to drive the locking mechanism to lock the rotation of the reel when the weight of the load is applied to the support belt, and wherein the reel is released by the locking mechanism when the weight of the load is removed from the support belt.
In at least some embodiments of the invention, the support belt can be provided separately for being fitted to the reel for winding up or unwinding of the support belt by the reel.
Typically, the support belt when fitted to the device hangs from the reel and wraps about one side of the actuator element for applying the force to the actuator element to drive the actuator element about the second axis of rotation.
Typically, the device further comprises a pulley wheel for being rotated drive rotation of the reel to wind up or unwind the support belt in the absence of the weight of the load being applied to the support belt, and a pulley belt passing about the pulley wheel and arranged for being pulled to drive the rotation of the pulley wheel. Typically, the pulley wheel is arranged to rotate about the first axis of rotation.
Typically, the locking mechanism comprises:
at least one ratchet wheel arranged to rotate about the first axis of rotation with the rotation of the reel; and
at least one pawl pivotable about the second axis of rotation into engagement with the ratchet wheel to lock the reel.
Typically, the actuator element is disposed in an offset position with respect to the second axis of rotation and is arranged to be driven about the second axis of rotation with application of force to the actuator element by the support belt upon the weight of the load being applied to the support belt, and wherein the pawl is located to be driven into engagement with the ratchet wheel by the rotation of the actuator element about the second axis of rotation.
Typically, the first axis of rotation is defined by a rotatably mounted main shaft, and the reel and the pulley wheel are fixedly mounted on the main shaft.
Typically, the second axis is defined by a rotatably mounted ancillary shaft, and the pawl and the lever arm are fixedly mounted on the further shaft.
Typically, the actuator element comprises a shaft member, and an end region of the at least one pawl is mounted to the shaft member for driving the pawl about the second axis of rotation when the shaft member is driven about the second axis of rotation.
In at least some embodiments, the ratchet wheel is disposed in abutment with the reel.
Typically, a device embodied by the invention further comprises a damping system for damping the locking of the reel by the locking mechanism. Most typically, the damping system is configured to drive disengagement of the locking mechanism to permit rotation of the reel for unwinding of the belt from the reel, when the weight of the load is removed from the support belt.
Typically, the damping system comprises a lever arm for being rotated in one direction about the second axis of rotation to a working position when the actuator element is driven about the second axis by the support belt, and the lever arm is biased against said rotation into its working position to thereby dampen the engagement of the ratchet wheel by the pawl. In particularly preferred embodiments, the damping system further comprises a pair of permanent magnets arranged for being moved relative to one another into a magnetically repelling relationship to bias the lever arm against rotation into its working position. Generally, one of the magnets is disposed for being moved into the magnetically repelling relationship with the other one of the magnets with the rotation of the lever arm, the magnetic repulsion between the magnets being sufficient to drive the magnets apart to rotate the lever arm about the second axis of rotation in an opposite direction to disengage the pawl from engagement with the ratchet wheel upon the weight of the load being removed from the support belt.
By damping the rotation of the at least one pawl into engagement with the ratchet wheel, smooth operation of the device may be obtained and sudden “jolting” as the pawl engages the ratchet wheel avoided or minimised, thereby also minimising wear and the risk of damage to the device.
Typically, the device comprises a pair of ratchet wheels and a pair of pawls, and each said pawl is arranged to engage with a corresponding one of the ratchet wheels, respectively. In such embodiments, the reel is typically disposed between the ratchet wheels.
In another aspect of the invention there is provided a weight bearing device for being located overhead to support the weight of a load applied to the device in use, the device comprising:
a support belt for supporting the load;
a reel for winding up or unwinding the support belt, the reel being rotatable about a first axis of rotation;
at least one ratchet wheel arranged to rotate about the first axis of rotation with the rotation of the reel;
at least one pawl pivotable about a second axis of rotation;
an actuator element disposed in an offset position with respect to the second axis of rotation and arranged to driven about the second axis of rotation by application of force to the actuator element by the support belt when the weight of the load is applied to the support belt, the pawl being located to be driven into engagement with the ratchet wheel with the rotation of the actuator element about the second axis of rotation to lock the reel against rotation about the first axis of rotation and thereby unwinding of the support belt;
at least one pair of permanent magnets; and
a lever arm for being rotated in one direction about the second axis when the actuator element is driven about the second axis by the support belt, and one of the permanent magnets is disposed for being moved into a magnetically repelling relationship with the other one of the magnets with the rotation of the lever arm to dampen the engagement of the ratchet wheel by the pawl, the magnetic repulsion between the magnets being sufficient to drive the magnets apart to rotate the lever arm about the second axis of rotation in an opposite direction to disengage the pawl from the ratchet wheel upon the weight of the load being removed from the support belt.
Typically, in embodiments of the invention the one said magnet is mounted to the lever arm. Most typically, the other one of the magnets is mounted in a fixed position.
Typically, the support belt for supporting the load of a device embodied by the invention includes a coupling component on a free end of the support belt for coupling of a load bearing element to the support belt.
In at least some embodiments of a device of the invention, the device is configured for being mounted to a ceiling of a room. In particularly preferred forms, the device can be mounted to the ceiling via a track secured to the ceiling, and the device further comprises one or more rollers for permitting rolling of the device along the track on the rollers allowing the device to be moved about the room. Most typically, the device comprises at least one pair of opposed rollers for rolling along the track.
In another aspect there is provided a method of providing a weight bearing device embodied by the invention, the method comprising:
providing the support belt for supporting the load; and
fitting the support belt to the reel of the device for winding up or unwinding of the support belt by the reel.
In another aspect there is provided method for providing a weight bearing device embodied by the invention, comprising;
providing the support belt for supporting the load;
providing a coupling component for coupling a load bearing element to the support belt for bearing of the load by the load bearing element; and
fitting the coupling component to a free end of the support belt.
In embodiments in accordance with this aspect of the invention in which the support belt for supporting the load is provided separately from the device, the method further comprises fitting the support belt to the reel of the device for winding up or unwinding of the support belt by the reel. In other embodiments in which the support belt is provided already fitted to the reel, the coupling component can be fitted to the support belt with the device in situ, or the coupling component can be fitted to the support belt and the device can then be mounted in position (e.g., mounted on a track secured to the ceiling of a room) for use of the device.
Typically, the coupling component is configured to mate with a connector of the load bearing element.
In another aspect of the invention there is provided a method for raising and/or carrying a load, comprising:
providing a weight bearing device embodied by the invention; and
raising and/or lifting the load whilst using the device of the invention to support the load via the support belt of the device.
The load bearing element for being coupled to the support belt of a device in accordance with the invention, or which is coupled to the support belt, can for instance, be a hoist for facilitating the raising and/or carrying of the load.
Typically, in embodiments of the invention the load is a person.
Advantageously, in embodiments as described herein, the support belt of the device can be lowered to a required height when the device is mounted in position overhead to allow attachment of the load bearing element. For instance, where a person is unable to leave the bed on their own accord or it is undesirable for them to do so, it may be necessary to lift the person entirely from the bed to a chair or trolley, or to move them whilst raised to another location, for e.g., treatment, therapy, showering and/or making the bed up with fresh bed sheets or linen. In such instances, the support belt of the device can be lowered to a required height to allow an extended belt of a hoist to be coupled to the support belt for operation of the hoist to climb its extended belt for raising of the hoist and thereby the person using e.g., a sling or harness located about the person and coupled to the hoist as is conventionally known. As will be understood, the reel of the device of the invention locks against rotation so that the support belt is unable to unwind from the reel once sufficient weight of the hoist is applied to the support belt to activate the locking mechanism of the device. The person may be raised in a seated or reclined position depending on the type of sling or harness utilised.
Various electrically operated hoists that may be used in combination with a device embodied by the invention are known to the skilled addressee. Such electrical hoists may be remotely controlled or be controlled via a control pad connected to the hoist by a cable.
Rather than being mounted to a ceiling directly or via a track system secured to the ceiling, in other embodiments the device can be mounted overhead to any suitable support, such a moveable or fixed position support or support frame.
Accordingly, devices embodied by the invention in one or more forms have versatility of application and are robust in form. Further, they can offer a cost effective means for supporting the weight of a load such as during the lifting and/or raising of a person as described above.
The device and methods of the invention have particular application in hospitals, aged care facilities, and private settings where facilitated raising, lifting and/or moving about of aged, injured, infirm or other patient(s) or person(s) is required. However, the invention is not limited to use with people and also has zoological or veterinary use in instances where lifting and/or moving of larger animals (e.g., such as dogs, sheep, goats, horses and members of the ape family) is needed, such as following an examination or a surgical operation where the animal needs to be lifted back onto its paws or hooves, and/or be moved from an examination or surgical table to a trolley, cart or recovery area.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers, integers or steps.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the invention as it existed in Australia or elsewhere before the priority date of this application.
The features and advantages of the present invention will become further apparent from the following detailed description of exemplary embodiments of the invention together with the accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
An embodiment of a weight bearing device 10 of the invention in the form of a trolley for being mounted overhead to a track secured to a ceiling is illustrated in the accompanying drawings. The side covers enclosing the internal workings of the device are not shown. As illustrated in
As shown in
To avoid or minimise the pawls ramming into engagement with the ratchet wheels and so causing jolting, wear and damage to the device, the device 10 is further provided with a damping system for damping the engagement of the pawls 20 with the ratchet wheels 16. In particular, in the embodiment illustrated in
When the weight applied to the support belt 26 is removed, the magnetic repulsion between the magnets 34 and 36 is sufficient to drive the magnets apart. This rotates the lever arm 32 back about the ancillary shaft 22 causing the ancillary shaft to rotate in an opposite direction whereby each pawl is withdrawn from engagement with its corresponding ratchet wheel. With the disengagement of the pawls, the reel 12 is free to rotate. The support belt 26 can then be raised or lowered in the absence of the load on the belt.
In at least some embodiments, the position of the permanent magnet 34 and/or 36 can be adjustable to adjust the weight which needs to be applied to the support belt in order to drive the pawls 20 into engagement with the ratchet wheels 16. Typically, the “engagement weight” which needs to be exceeded before the pawls will engage with the ratchet wheels is set at about 500 grams which allows for the free weight of a length of the support belt to hang from the reel and a coupling component fitted to the free end of the belt (as described further below), as well as a predetermined weight margin.
Each end of the main shaft 14 is rotatably mounted to a corresponding end plate 38 as illustrated in
As again illustrated in
Thus, raising or lowering the support belt to a desired height in the absence of a load being applied to the support belt is simply a matter of pulling one side of pulley belt 40 in the appropriate direction. The pulley belt can be any type of belt deemed suitable, and the term “pulley belt” is to be taken in its broadest sense to include any length of material which functions to drive rotation of the pulley wheel. The pulley belt can, for instance, be in the form of a cord, cable or chain. In at least some embodiments, the pulley belt can be a beaded cord or chain. In this instance, corresponding depressions may be provided around the pulley wheel in which the beads of the cord or chain lie to provide purchase between the cord and the pulley wheel for rotation of the pulley wheel when the cord/pulley belt is pulled as is conventionally known in roller blind and roller shade arrangements. In at least some embodiments, the pulley belt can be fabricated from a silicone or other synthetic material such as polyurethane, including embodiments in which the pulley cord is a beaded cord as described above. Fabrication of the pulley cord entirely from a silicone compound or other synthetic polymer material is desirable as it can have good hand feel whilst at the same time provide for ease of cleaning and thereby cleanliness and good hygiene.
In embodiments in which the pulley belt is a beaded chain of the general type as described above the belt may, for instance, be a beaded metal chain.
Likewise, the support belt 26 can be any type of belt deemed suitable and may, for example be a flat strip of material or webbing, or a strap, cord, chain, cable or wire, which performs the intended purpose of the support belt. Typically, the support belt is a strip of woven webbing such as is commonly used for automotive restraints, harnesses and seatbelts, e.g., commercially available woven polyester, nylon or polypropylene webbing, or webbing fabricated from other suitable synthetic material(s). As the device 10 of the invention may be utilised to lift the full weight of a person, the support belt must be strong enough to do this without snapping. Generally, in embodiments of the invention, the support belt 26 will have a “safe load” breaking strain of 300 kg or 350 kg or more. Depending on the selected material from which the support belt 26 is fabricated, in some embodiments the breaking strain of the support belt may even be up to 1 tonne or greater, and even up to 2 tonnes or more.
Further, the support belt in particularly preferred embodiments is also desirably essentially non-stretchable under normal working loads applied to the support belt in use.
The support belt is of a length sufficient to allow the support belt to be unwound from the reel 12 by rotation of the pulley belt 40 to a suitable height for coupling of a belt of a load bearing element in the form of a hoist to the support belt for physically raising or lifting of a person by the hoist when operated to climb its extended belt as conventionally known. Suitable such electrically powered hoists for this purpose are well known in the field of care of aged, ill, infirm and incapacitated persons, and any such hoist may be employed in combination with a device embodied by the invention. As will be understood, to raise or lift a person with the use of a hoist, sling(s), belt(s), harness(es), yoke(s) and/or other aid(s) for holding the person are attached to the hoist. The hoist is then operated when the person is secured in the sling(s) or by the particular lifting aids utilised, to raise or lift the person. As will be understood, the reel 12 of the device 10 locks against rotation by engagement of the pawls 20 with the ratchet wheels 16 so the support belt is held against extension from the device, once the additional weight of the hoist applied to the support belt 26 exceeds the engagement weight for operation of the pawls. As with the support belt 26, the belt of the hoist can be a length of woven webbing, or e.g., a line, cord, cable, wire or the like suitable for purpose.
As further illustrated in
In other embodiments, rather than being in the form of a trolley as described above, a device in accordance with the invention can be configured for being mounted overhead in a stationary position on a ceiling or suitable frame or stand for use of the device. In such instances, a modified form of the mounting bracket 48 can be utilised, or the mounting bracket 48 may not be provided and the device can be provided with other mounting(s) for securing of the device to the support.
For the purpose of coupling the support belt 26 to a hoist or other load bearing element as described above, a coupling component can be provided on the free end of the support belt for coupling of the load bearing element to the support belt. Any appropriate coupling system for connecting the load bearing element to the support belt can be employed. For instance, the coupling component fitted to the belt can be a carbine type connector with a spring-loaded gate, for reception of a buckle, hook, or closed loop fitting or other connector provided on the belt of the hoist, or vice versa. In particularly preferred embodiments, the coupling component fitted to the support belt 26 of the device of the invention mates with the connector of the hoist. The selected coupling component can be fitted or retrofitted to the support belt whilst the device is mounted in position in situ with the support belt fitted to the reel of the device. Alternatively, the support belt can be provided separately from the device and the coupling connector fitted to the free end of the support belt before the belt is fitted to the reel of the device.
Other load bearing elements besides hoists that can be used in combination with a device embodied by the invention include bars, handles (e.g., conventional triangle handles), straps and other attachments for being grasped by a person in e.g., bed to provide support to assist the person to reposition him or herself into a reclined or seated position such as may be necessary or desirable for undergoing an examination by a physician, or for eating, reading, conversing with visitor(s), or watching television from bed. Desirably, such load bearing elements are sufficiently heavy themselves when attached to the support strap to cause the reel of the device to be locked against rotation by operation of the pawls of the device.
In the above described embodiments, permanent magnets 34 and 36 are employed to bias the lever arm 32 against rotation to its working position to thereby dampen the rotation of the pawls 20 into engagement with the ratchet wheels 16. However, other damping means than permanent magnets can be used for this purpose. For instance, spring arrangements can be utilised in which one or more compression and/or tension springs can be arranged to bias the lever arm against rotation to its working position when weight is applied to the support belt 26 in use. As an example, one end of a tension spring can be connected to the lever arm and an opposite end of the spring can be connected to a stationary point of the device 10, so that the spring stretches to apply a biasing force to the lever arm against rotation to its working position, and which rotates the lever arm back to its initial resting position when the weight of the load is removed to the support belt. However, springs and other biasing means which could be used such resilient bands tend to lose their elasticity and prone to damage and wear over time. For these reasons, the use of permanent magnets to bias the lever arm 32 against movement into its working position is preferred.
Further, whilst the ratchet wheels 16 are shown as separate components to the reel 12 in the accompanying drawings, in other embodiments the ratchet wheels can be integrally formed with the reel or can, for example, form the side walls of the reel.
In still further embodiments, a weight bearing device in accordance with the invention can be locked in position on an overhead rail or other overhead support (e.g., a support frame) to provide a fixed support point that does not move. In preferred such embodiments, the device may be unlocked for being moved, slid or rolled along the rail or support and locked in position at a new location on the rail or support as required.
Indeed, a device embodied by the invention may be used in a range of different ways and for different purposes. For example, the device may be locked in a stationary overhead position above a patient on a operable bed or trolley or the like, for securing of the patient to the support belt of the device by harness(es), sling(s) and/or other lifting aids in the absence of a hoist. The bed or trolley can then be lowered whereby the person remains supported over the bed or trolley by the device. The device may then be unlocked from the overhead rail or support and moved along the rail/support away from the bed or trolley for changing of bedsheets, toileting, attendance to pressure care, or other requirements. Likewise, in instances where the device is retained overhead in a fixed position, the bed or trolley can be lowered and removed from under the patient whilst the patient remains suspended supported by the support belt of the device. As will be understood, the patient is then returned to a bed or trolley by relocating the bed or trolley under the patient, and the bed or trolley is raised to take the weight of the patient to allow the patient to be uncoupled from the support belt 26 of the device. In doing so, the patient can also be repositioned on the bed or trolley as may be required.
This method may also be used in a morgue or funeral parlour to assist with moving the body of a deceased person.
Hence, a device in accordance with the invention may be used as a standalone weight bearing device without the need for connection of a hoist to the support belt of the device.
In still further embodiments, the support belt 26 of a device of the invention can be mounted to an overhead rail and a strap of walking sling connected to the belt to support a patient during gait/walking training for therapy following e.g., injury or stroke. In this instance, the device may be drawn along the rail by the patient as they walk and provide support for the patient against falling.
Other uses of a device embodied by the invention include locating the device over a walking race or treadmill wherein a patient is supported by the device via a walking sling. Likewise, the device could be used to support therapy bolsters or other therapeutic, rehabilitation or exercise equipment requiring support from above, and all such uses of a device as described herein are expressly encompassed.
From the above, it will be understood that embodiments of the invention may provide one or more of the following advantages:
Although a number of embodiments of the invention have been described above it will be understood that various modifications and changes may be made thereto without departing from the scope of the invention. The above described embodiments are therefore only illustrative and are not to be taken as being restrictive.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017904309 | Oct 2017 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2018/051151 | 10/24/2018 | WO | 00 |
