DK201270234A - Chair lifter - Google Patents

Description

Chair lifter

Field of the invention

The present invention relates to a device for lifting and moving a chair in which a person is sitting.

Background of the invention

People working in hospitals, nursing homes and the like have to deal with a lot of heavy lifts and movements of patients / users every day. In many cases, such lifts and movements may be performed using cranes or lifting devices, which have been developed especially for such purposes. This is especially true when a person needs assistance to enter or leave a bed or to be seated in or raised from a chair.

When it comes to placing a person at a table, for instance for dining, and removing a person from such a table, the conventional types of cranes and lifting devices are usually of no great help, because the movement includes a horizontal displacement of a chair under or away from the table along with the person moving.

This problem has been solved by mounting small wheels onto the chair, but this solution suffers from a number of drawbacks. For instance, such wheels must be mounted on every chair to be used in this way and must be regularly tightened. More importantly, small wheels do not roll too well on most floor surfaces, meaning that it still requires a substantial force from the assisting person to place the chair carrying a person under the table and that the chairs often break and must be replaced relatively soon because of the twisting forces they are subjected to.

Brief description of the invention

It is an object of the present invention to provide a solution which enables to use almost any kind of existing chair without modification thereof, which is easy and straightforward to use and which is more gentle not only to the assisting person and the person being seated. but also to the floor and to the furniture than other solutions known in the art.

The present invention relates to a device for lifting and moving a chair in which a person is seated, said device comprising a base part provided with at least three wheels, preferably four wheels, a support part comprising two elongated and parallel support poles, preferably in the form of cylindrical tubes, extending in an upward direction from the base part, a chair engaging part, which is engaged with the support part extending in a forward direction substantially perpendicular to the support poles and which is movable in a direction parallel to the support poles, and an open spindle actuator extending between the support poles and parallel to the support poles from the base part, where the chair engaging part is engaged with the open spindle actuator so that rotation of the actuator spindle causes the chair engaging part to move upwards or downwards along the support poles, depending on the direction of rotation. A configuration like this is advantageous in that the use of an open spindle actuator allows the chair engaging part to travel over a very long distance so that it is both able to move to a very low position (for instance for lifting a person sitting in an easy chair or another chair with a low clearance beneath) and to a sufficiently high position to make sure that the feet of the person lifted are free of the floor.

In an embodiment of the invention, a transverse handle bar connects the support poles near the upper ends thereof, the handle bar being rigidly fixed to each of the two support poles.

With this construction, the parallelism and stability of the support poles is obtained by using the transverse handle bar as a distance piece to make sure that the distance between the upper ends of the two support poles is maintained at its correct value. This reduces the number of very accurately performed welded joints needed to obtain a support part with two exactly parallel support poles in exactly the correct distance from each other. Furthermore, it allows for bushings and the like surrounding one or both of the support poles to be added, replaced or removed without having to destroy any such welded joints.

In an embodiment of the invention, the chair engagement portion comprises a lifting bridge with an inner thread, which is engaged with the actuator spindle, and two bushings slidably arranged around the two support poles, respectively, so that the support poles work as supports. for the chair engaging part and as guides for the motion, when the spindle is rotated and the chair engaging part moves along the support poles.

Letting the chair engaging part comprise bushings around the support poles allows the support poles not only to support the chair engaging part (with and without a load placed thereon) but also to guide the upward and downward motion of the chair engaging part in a very accurate and stable way.

In an embodiment of the invention, the chair engaging part comprises a top frame which is tiltable in relation to the other parts of the chair engaging part.

The use of a tiltable top frame is advantageous for obtaining the best possible contact between the chair engaging part and the chair to be lifted, and it may be used to assist the person in the chair to rise from the chair and stand up by tilting the chair a bit forwards.

In an embodiment of the invention, the top frame is arranged so that it may be tilted forwards by applying a downward pressure to its front part or by applying an upward pressure to its rear part, and a sliding friction lock is arranged to prevent the rearmost part of the top frame from moving downwards, thereby preventing the top frame from tilting backwards unless the friction lock is released, the initial position of the top frame when the friction lock is released being tilted a bit backwards.

This configuration makes sure that the top frame aligns itself as well as possible with the underside of the chair being lifted and that this alignment is maintained even after the contact between the top frame and the chair has been broken, when the chair has been set down again.

In an embodiment of the invention, the friction lock may be released manually at any position of the chair engaging part or automatically by lowering the chair engaging part to its lowest possible position.

The automatic release of the friction lock ensures that the top frame will always be in its initial position and ready for lifting a chair, when the chair engaging part is lowered to its lowest possible position, which will typically be the case, when the device is "parked" and not in use.

In an embodiment of the invention, an actuator is connected to the rearmost portion of the top frame, so that the top frame may be tilted forwards or backwards by extending or protracting the actuator, respectively.

Controlling the tilt of the top frame by means of an actuator means that the chair lifted or supported by the chair engaging part may be tilted slightly forwards in order to assist the person in the chair to rise from the chair and stand up as mentioned above.

In an embodiment of the invention, one or more of the wheels are automatically braked when the chair engaging part is lowered to its lowest possible position.

For safety reasons, it is advantageous that the device is prevented from rolling when it is in its "parking" position with the chair engaging device in its lowest possible position.

In an embodiment of the invention, the device further comprises a brake working on one or more of the wheels, which brake may be actuated, locked and released by a person operating the device.

For safety reasons, it is advantageous that a person operating the device is able to prevent the device from rolling when it is not intended, even if the chair engaging part is not in its lowest possible position.

In an embodiment of the invention, a control unit, preferably in the form of push buttons, for operating the open spindle actuator and, if present, the actuator for tilting the top frame are placed at the upper end of one or more of the support poles without any wires for the control unit extending outside the device.

Placing the control unit within the device itself without any extending wires reduces the risk of tripping and other accidents related to loose wire catching or being caught by different objects when operating and moving the device.

In an embodiment of the invention, the device further comprises one or more weighing cells and a display arranged to measure and display, respectively, the weight applied to the top frame by one or more objects lifted by the device.

Using a weighing system, which is built into the chair lifting device allows for a simple and easy way of weighing a person without any form of inconvenience whatsoever to the person being weighed.

Figures A few exemplary embodiments of the invention will be described in the following with reference to the figures, of which fig. 1a is a front view of a first embodiment of the invention, fig. lb is a perspective view of this first embodiment of the invention, fig. lc is a side view or this first embodiment of the invention, fig. 2a is a front view of a second embodiment of the invention, fig. 2b is a perspective view of this second embodiment of the invention, fig. 2c is a side view or this second embodiment of the invention, fig. 3a is a front view of a third embodiment of the invention, fig. 3b is a perspective view of this third embodiment of the invention, fig. 3c is a side view or this third embodiment of the invention, fig. 4a is a front view of a fourth embodiment of the invention, fig. 4b is a perspective view of this fourth embodiment of the invention, and fig. 4c is a side view or this fourth embodiment of the invention.

Detailed description of the invention

Figs, la-lc are a front view, a perspective view and a side view, respectively, of a device 1 for lifting and moving a chair in which a person is seated according to a first embodiment of the present invention. For the sake of convenience, such a device will simply be referred to as a chair lifter 1 in the following.

The illustrated chair lifter 1 comprises a base part 2 having a base frame 3, onto which two larger side wheels 4, a smaller pivotable front wheel 5, and a smaller pivotable rear wheel 6 are mounted.

The chair lifter 1 only rolls on three wheels 4-6 at a time. When no load is lifted or supported by the chair lifter 1 and the chair lifter 1 is simply standing or being rolled across a floor, the center of gravity is somewhere between the side wheels 4 and the rear wheel 6, and the chair lifter 1 rolls on these three wheels 4, 6 only. When, on the other hand, a load is lifted or supported by the chair lifter 1, the center of gravity will be placed in front of the side wheels 4, and the chair lifter 1 will stand or roll on the side wheels 4 and the front wheel 5. In both cases, however, the center of gravity will be placed almost directly above the rotational axis of the two side wheels 4.

Only a slight tilt of the chair lifter 1 is needed to change between being supported by the front wheel 5 and the rear wheel 6, respectively. Thus, this configuration of wheels 4-6 ensures that the chair lifter 1 is always stable and not inclined to topple while, at the same time, the use of only three wheels 4-6 at a time ensures that it is easily maneuvered, even when carrying a chair with a person thereon.

According to the illustrated side wheels 4 mounted on the outer side of the base frame 3, they may be mounted on the inner side thereof, which may be convenient if the chair lifter 1 is to be used with chairs with only a relatively narrow clearance between the legs thereof. A battery 7 for supplying the necessary electricity for operation of the chair lifter 1 and the necessary control electronics (not shown) for operating the chair lifter 1 are arranged near the front end of the base part 2. A protective tube 8 guides power and signal wires from the battery 7 and the electronics to the rear end of the base part 2.

The triangular shape of the front end as well as the rear end of the base part 2 reduces the risk of hitting the chair lifter 1 with the feet for the person sitting in the chair and for the person operating the chair lifter 1, respectively. A motor 9 for an open spindle actuator 10 is mounted on the base part 2 just in front of the rear wheel 6, the open spindle actuator 10 extending from the motor 9 in an upward and slightly backward direction. A support pole 11 extends from each side of the base part 2 near its rear end in the same direction as the open spindle actuator 10 so that the two support poles 11 and the open spindle actuator are all parallel to each other, the open spindle actuator 10 being placed between the two support poles 11.

The slightly backward direction of the support poles 11 and the open spindle actuator 10 ensures that there is room for a chair back should the chair be lifted with such one.

In the illustrated embodiment, the support poles 11 are connected to the base frame 3 by means of welding in order to obtain the necessary strength and stability of the construction. When performing this welding, it is important to be very precise with respect to the direction of the support poles 11 as well as the distance between them.

In the upper end of the support poles 11, the distance between them is kept correct by means of a transverse handle bar 12, which passes through both of the support poles 11. The handle bar 12 is fixed to the support poles 11 in order to make sure that the parallelism of the support poles 11 and the distance therebetween is maintained during use of the chair lifter 1. In the illustrated embodiment, this fixation is made by using pop rivets 13. In other embodiments, however, other fixation means, such as for instance screws, may be used.

At each end of the handle bar 12, a hand grip 14 is placed for the convenience of the person operating the chair lifter 1.

In the illustrated embodiment, a small control unit 15 comprising two push buttons is arranged for operating the open spindle actuator 10 in the two directions, respectively. In this embodiment, the wires from the control unit 15 runs inside the support pole 11 to the base part 2 and the control electronics placed therein. In other embodiments, however, the control unit may be an external unit connected to the chair lifter 1 by means of a loose (possibly spiraled) wire. In this case, the external control unit may be provided with some sort of hook so that it can hang on the handle bar 12 when not being used.

The chair engaging part 16 of the chair lifter 1 comprises a lifting bridge 17, which connects the two support poles 11 and is engaged in the thread of the open spindle of the actuator 10 so that when the spindle is rotated, the bridge (and thereby the complete chair engaging part 16) moves up or down along the support poles 11 depending on the direction of rotation.

The lifting bridge 17 is connected to each of the support poles 11 by means of a bushing 18, which is arranged to slidably fit around the support pole 11 so that the bushing may slide along the support pole 11. The bushing 18 is provided with a lining of a plastic material, such as for instance POM, in order to obtain the ability to slide along the support pole 11 while fitting tightly around it.

From the lifting bridge 17, two lifting arms 19 extend in a forward direction. A tiltable top frame 20 is mounted on the lifting arms 19 with its pivotal axis 21 placed at the front end of the lifting arms 19 and relatively close to the front end of the top frame 20. This means that the top frame 20 can be tilted forwards either by pressing down the front end thereof or by lifting up the rear end thereof and vice versa. A sliding friction lock 23 of which only a part can be seen in fig. lc is connected to the top frame 20 at a rear attachment point 22 thereof and arranged to prevent the rearmost end of the top frame 20 from moving downwards unless the friction lock 23 is released. This means that, until the friction lock 23 is released, the top frame 20 may be tilted in a forward but not in a backward direction. In the illustrated embodiment, the attachment point 22 is placed significantly higher that the surface of the top frame 20 is arranged to support the chair being lifted. This means that the top frame 20 may be twisted to a certain extent without interfering with the friction lock 23.

The friction lock 23 may be released by lifting a release handle 24, either manually or automatically by moving the chair engaging part 16 to its lowest possible position, in which the release handle 24 is lifted due to contact with the base part 2.

On the outer side of each of the lifting arms 19, a wheel braking pin 25 is arranged. When the chair engaging part 16 is moved to its lowest possible position, this pin 25 is pressed against the side wheel 4, which is thereby prevented from rotating.

To use the chair lifter 1, the chair engaging part 16 must be lowered to a position slightly above the lowest possible position in order to avoid the wheel braking pins 25 from braking the side wheels 4, and the friction lock 23 must be released by lifting the release handle 24.

The chair lifter 1 may then be rolled on its side wheels 4 and the rear wheel 6 and placed with the chair engaging part 16 protruding under the seat of the chair to be lifted from the back side thereof.

Now, the chair engaging part 16 may be lifted by activating the open spindle actuator 10 by pressing the relevant button on the control unit 15. When the moving chair engaging part 16 reaches the underside of the chair, the tiltable top frame 20 will automatically tilt forward until optimal contact with the chair is achieved, so that the chair will rest safely and stable on the chair engaging part 16 when being lifted from the floor.

Now supported by the side wheels 4 and the front wheel 5, the chair lifter 1 may be moved with the chair and the person sitting therein to any desired position, such as for instance a dining table, whereupon the chair may be lowered gently to the floor by pressing the other button on the control unit 15 for rotating the open spindle actuator 10 in the opposite direction than when lifting the chair. The friction lock 23 ensures that the top frame 20 stays in optimal contact with the chair while lowering it to the ground, whereupon the chair lifter 1 may again be removed from the chair.

The relatively simple construction of the chair lifter 1 significantly reduces the production costs. Furthermore, the use of an open spindle actuator 10 allows for a very long travel distance of the chair engaging part 16. In fact, a travel distance of up to 600 mm may be achieved with a lower height of the top frame of only 163 mm . This means that the chair lifter 1 is able to go under almost any ordinary chair and even many types of easy chairs should it be needed. At the same time, the long travel distance ensures that the person in the chair may be lifted enough to get the feet off the floor.

Figs. 2a-2c are a front view, a perspective view and a side view, respectively, of a chair lifter 1 according to a second embodiment of the present invention.

This second embodiment is very similar to the first embodiment illustrated in figs, la-lc, the only difference being that this second embodiment of the chair lifter 1 is provided with a brake, which may be actuated, locked and released by means of a brake grip 26 similar to a hand brake grip on a bicycle.

By means of a cable extending within the support pole 11, the brake grip 26 is connected to a brake plate 27 placed just behind the side wheels 4 so that when the brake grip 26 is pulled, the brake plate 27 is pushed forwards against the back side of the side wheels 4, thereby preventing them from rotating. As can be seen in fig. 2c, the brake plate 27 presses against the side wheel 4 just below the horizontal center line thereof. This means that the braking effect is optimized against backward motion of the chair lifter 1, which is important when using the rise-up function of the chair lifter 1, which will be described below.

Figs. 3a-3c are a front view, a perspective view and a side view, respectively, of a chair lifter 1 according to a third embodiment of the present invention.

This third embodiment is very similar to the second embodiment illustrated in figs. 2a-2c, the only difference being that in this third embodiment of the chair lifter 1, the friction brake 23 has been replaced by a linear actuator 28 arranged between the non-tiltable part of the chair engaging part 16 and the rear attachment point 22 of the top frame 20.

The control unit 15 has been provided with two more push buttons (not shown) for activating a motor (not shown) driving the linear actuator 28 so that in this embodiment, the top frame 20 can be automatically tilted either forwards or backwards.

This provides the chair lifter 1 with a rise-up function by means of which the person sitting in the chair may be assisted in rising from the chair. This is done by using the linear actuator 28 to tilt the top frame 20, and thereby also the chair in which the person is sitting, forwards, which makes it easier to rise from the chair.

The similarity between the illustrated second and third embodiments of the chair lifter 1 allows for a simple upgrade of the chair lifter 1 from the second to the third embodiment by simply replacing the friction lock 23 with the linear actuator 28 and the accompanying motor, cabling and control system.

Figs. 4a-4c are a front view, a perspective view and a side view, respectively, of a chair lifter 1 according to a fourth embodiment of the present invention.

This fourth embodiment is very similar to the third embodiment illustrated in figs. 3a-3c, the only difference being that this fourth embodiment of the chair lifter 1 is provided with a weighing system 29-31, which is built into the chair lifting device 1 and allows for a simple and easy way of weighing the person sitting in the chair without any form of inconvenience whatsoever to that person.

The primary components of the weighing system are two weighing cells 29 placed onto the two sides of the top frame 20, respectively, an additional top frame 30 placed onto the weighing cells 29 parallel to the top frame 20 below the weighing cells 29 and a weight display, which in the illustrated embodiment is placed behind the lifting bridge 17 of the chair engaging part 16. The necessary cabling and control equipment for the weighing system are not shown in the figures.

The invention has been exemplified above with reference to specific examples of embodiments of the invention. It is to be understood, however, that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the patent claims following hereafter.

List of reference numbers 1. Chair lifter 2. Base part of chair lifter 3. Base frame 4. Side wheel 5. Pivotable front wheel 6. Pivotable rear wheel 7. Electric battery 8. Protective tube for wires 9. Motor for open spindle actuator 10. Open spindle actuator 11. Support pole 12. Transverse handle bar 13. Pop grated for fixating handle bar to support pole 14. Hand grip 15. Control unit 16. Chair engaging part 17. Lifting bridge 18. Bushing for support pole 19. Lifting arm 20. Top frame 21. Pivotal axis for top frame 22. Rear attachment point of top frame 23. Sliding frictional lock 24. Release handle for frictional lock 25. Wheel braking pin 26. Brake grip 27. Brake plate 28. Linear actuator 29. Weighing cell 30. Additional top frame 31. Weight display

Claims (11)

1. A device for lifting and moving a chair in which a person is sitting, said device comprising a base part provided with at least three wheels, preferably four wheels, a support part comprising two elongated and parallel support poles, preferably in the form of cylindrical tubes, extending in an upward direction from the base part, a chair engaging part, which is engaged with the support part extending in a forward direction substantially perpendicular to the support poles and which is moveable in a direction parallel to the support poles, and an open spindle actuator extending between the support poles and parallel to the support poles from the base part, wherein the chair engaging part is engaged with the open spindle actuator so that rotation of the actuator spindle causes the chair engaging part to move upwards or downwards along the support poles, depending on the direction of the rotation.

2. A device according to claim 1, wherein a transverse handle bar connects the support poles near the upper ends thereof, the handle bar being rigidly fixed to each of the two support poles.

3. A device according to claim 1 or 2, wherein the chair engaging part comprises a lifting bridge with an inner thread, which is in engagement with the actuator spindle, and two bushings slidably arranged around the two support poles, respectively, so that the support poles work as supports for the chair engaging part and as guides for the motion, when the spindle is rotated and the chair engaging part moves along the support poles.

4. A device according to any of the preceding claims, wherein the chair engaging part comprises a top frame, which is tiltable in relation to the other parts of the chair engaging part.

5. A device according to claim 4, wherein the top frame is arranged so that it may be tilted forwards by applying a downward pressure to its front part or by applying an upward pressure to its rear part, and a sliding friction lock is arranged to prevent the rearmost part of the top frame from moving downwards, thereby preventing the top frame from tilting backwards, unless the friction lock is released, the initial position of the top frame when the friction lock is released being tilted a bit backwards.

6. A device according to claim 5, wherein the friction lock may be released manually at any position of the chair engaging part or automatically by lowering the chair engaging part to its lowest possible position.

7. A device according to claim 4, wherein an actuator is connected to the rearmost part of the top frame, so that the top frame may be tilted forwards or backwards by extending or protracting the actuator, respectively.

8. A device according to any of the preceding claims, wherein one or more of the wheels are automatically braked, when the chair engaging part is lowered to its lowest possible position.

9. A device according to any of the preceding claims further comprising a brake working on one or more of the wheels, which brake may be actuated, locked and released by a person operating the device.

10. A device according to any of the preceding claims, wherein a control unit, preferably in the form of push buttons, for operating the open spindle actuator and, if present, the actuator for tilting the top frame are placed at the upper end of one or more of the support poles without any wires for the control unit extending outside the device.

11. A device according to any of the preceding claims further comprising one or more weighing cells and a display arranged to measure and display, respectively, the weight applied to the top frame by one or more objects lifted by the device.