GB2449248A

GB2449248A - Articulating chair with sensor

Info

Publication number: GB2449248A
Application number: GB0709219A
Authority: GB
Inventors: Wayne Mayor
Original assignee: BRANDVITAL Ltd
Current assignee: BRANDVITAL Ltd
Priority date: 2007-05-14
Filing date: 2007-05-14
Publication date: 2008-11-19
Anticipated expiration: 2027-05-14
Also published as: GB0709219D0; GB2449248B

Abstract

An articulated chair 10 with a safety interface, the articulated chair 10 comprising: a control module (54 Fig 5), at least one actuator 26, 34 for articulating the chair 10; and a user interface 42 operatively connectable to the control module for controlling the operation of the actuators 26, 34. The safety interface (58 Fig 5) is connectable between the user interface 42 and the control module and is adapted to stop or reverse the actuators or override the user interface 42 when an unsafe condition or obstruction is sensed by one or more sensors 36, 38, 40. The sensors may be pressure sensors formed from a deformable web (Fig 4).

Description

Title: Articulated chairs

Description:

This invention relates to articulated chairs, and in particular, but without limitation to, lifting and/or reclining chairs for the elderly or infirm.

An articulated, or lifting/reclining, chair is often used by the elderly or infirm as an alternative to a conventional chair. Known lifting chairs generally comprise a base and a seat portion that is connected to the base by a lifting mechanism. In many cases, the lifting chair is fitted with a remote control that controls the lifting mechanism to raise or lower the chair as needed. A raised chair is easier for a user to get into and out of as it does not require the user to bend as much, or to support their weight in a knees-bent position. Many lifting chairs also have reclining functions that enable a user, once seated, to adopt a reclined or laid-flat position, which can be more comfortable and alleviate pressure pains caused by sitting in one position for extended periods.

This invention aims to provide an improved lifting/reclining chair.

According to a first aspect of the invention there is provided an articulated chair comprising: a base, a chair portion movable relative to the base, an actuator for moving the movable chair portion between first and second positions, a control means for controlling the operation of the actuator, and at least one sensor affixed to the chair and operatively connected to the controller for sensing the presence of an obstruction, wherein the at least one sensor and controller are together arranged to stop and/or reverse the actuator when the presence of an obstruction is sensed.

Advantageously, the invention reduces or eliminates the risk of an object becoming trapped underneath, or by, the chair during adjustment of the position thereof.

The movable chair portion may comprise any one or more of the group comprising: a support frame (chassis), a seat portion, a backrest portion, and a footrest portion of the chair.

The at least one sensor may be arranged to sense the presence of an obstruction located between the floor, and any one or more of the support frame, seat portion, or footrest portion of the chair. Additionally or alternatively, the at least one sensor may be affixed to the underside of the chair for sensing the presence of an obstruction beneath the chair. The at least one sensor may be affixed to the rear of the footrest and/or between the seat portion and the backrest portion of the chair.

Additionally or alternatively, the at least one sensor may be located within the seat portion and arranged to sense the presence of a person sitting on the chair.

According to a second aspect of the invention there is provided a safety interface for an articulated chair, the articulated chair comprising: a control module connectable to a power supply, at least one actuator for articulating the chair; and a user interface operatively connectable to the control module for controlling the operation of the at least one actuator; wherein the safety interface is connectable between the user interface and the control module and is adapted to override the user interface when an unsafe condition is sensed by one or more sensors An unsafe condition may arise when there is an obstruction located beneath the chair or in the path of a moving portion of the chair.

The safety interface may be connectable between the user interface and the control module.

The safety interface may further comprise a relay. One or more of the sensors may be wired to, and arranged to effect switching of, the relay.

Optionally, a capacitor may be wired in parallel with at least one of the sensors for delaying the switching of the relay.

Preferably, any one of the control module, actuator, user interface and sensor is connectable to any another of the control module, actuator, user interface and sensor using a plug and socket. Advantageously, such an arrangement facilitates modular assembly, disassembly and replacement/servicing of the components of the safety interface According to a third aspect of the invention there is provided a controller for controlling the operation of an articulated chair, the controller comprising: a control module connectable to a power supply; at least one actuator for articulating the chair; user interface operatively connectable to the control module for controlling the operation of the at least one actuator; and a safety interface adapted to override the user interface when an unsafe condition is sensed by one or more sensors.

The controller interface may further comprise a relay. One or more of the sensors may be wired to, and arranged to effect switching of, the relay.

Any one of the control module, power supply, actuator, user interface, safety interface and sensor may be connectable to any another of the control module, power supply, actuator, user interface, safety interface and sensor using a plug and socket. Advantageously, such an arrangement facilitates modular assembly, disassembly and replacement/servicing of the components of the controller The sensor may comprise a pressure sensor. The pressure sensor, where provided, may comprise first and second resiliently deformable webs each having at least one electrically conductive surface, the webs being maintained in a spaced apart relationship but being deformable so as to bring the electrically conductive surfaces into contact with one another. An apertured, resiliently compressible web may be located between the first and second webs. At least one of the first and second webs may comprise a plurality of projections that project at least partially into the apertures of the resiliently compressible web, the projections being arranged so as to reduce the separation between opposing conductive surfaces of the first and second webs.

The pressure sensor may comprise a pair of spaced-apart resiliently deformable electrical contacts with a discontinuous resiliently deformable spacer therebetween. The resiliently deformable electrical contacts may comprise a laminated structure. Preferably, the laminated structure comprises a flexible polymeric support web having a metallic coating on one surface thereof. The resiliently deformable spacer may comprise a web of apertured foam The actuator may comprise a telescopic actuator. The telescopic actuator, where provided, may comprise an electric motor.

A preferred embodiment of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1 and 2 are schematic side views of the rising and reclining mechanism of a rising chair; Figure 3 is a side and front view of a rising and reclining chair according to the invention; Figure 4 is a perspective view of a partially delaminated pressure sensor; Figure 5 is a schematic wiring diagram, incorporating a safety interface, for a raising and reclining chair according to the invention; and Figure 6 is a circuit diagram for the safety interface of Figure 5 In Figures 1 and 2, a chair 10 comprises a base 12 and a chassis 14.

The chassis 14 can be moved relative to the base 12 using a lifting mechanism 16 that is described below. A padded seat portion 18, on which a user can sit, is rigidly affixed to the top of the chassis 14. A padded back portion 20 and a footrest portion 22 are movably connected to the chassis 14 by a reclining mechanism 24, which is also described below.

The lifting mechanism 16 comprises a rigid linkage 26 that is pivotally connected, at its lower end, to a point located towards the rear of the base 12, and at its top end, to a point located towards the front of the chassis 14. A telescopic motor 28 is pivotally connected, at its lower end, to a point located towards the front of the base 12, and at its top end, to a point located towards the rear of the chassis 14. As can be seen by comparing Figures 1 and 2, the chassis 14, and hence the seat portion 18 can be raised or lowered by extending or retracting the telescopic motor 28 Since the linkage 26 has a fixed length, when the seat is raised, the chassis 14 tilts forwards. This has the advantage of making the chair easier to get into and out of when in a raised position.

By selecting an appropriate geometry for the lifting mechanism 16, the maximum height and tilt angle can be predetermined.

Also shown in Figures 1 and 2 is the reclining mechanism 24, which comprises a sub-chassis 30 to which the footrest 22 is rigidly affixed and a support frame 32 to which the backrest 20 is rigidly affixed. The support frame 32 and sub-chassis 30 are mechanically linked 36 in such a way that they move together to effect simultaneous reclining/raising of the backrest 20 and raising/lowering of the footrest 22.

One or more telescopic motors 34 cooperate with the chassis 14 and the mechanical linkage 36 to effect adjustment of the backrest 20 and footrest 22 positions.

In Figure 3, it can be seen that a first set of pressure sensors 36 are disposed on the front, rear and side edges of the underside of chair 10 to sense the presence of an obstruction located underneath the chair 10 A second set of pressure sensors 38 are disposed on the rear of the footrest 22 and between the seat 18 and back 20 portions of the chair 10 to sense the presence of an obstruction located between the main body of the chair 10 and the backrest 20 or footrest 22. A third pressure sensor 40 is located within the seat portion 18 for sensing the presence of a person or object on the chair 10.

The chair 10 can be raised/lowered and/or reclined using a wired remote control unit 42 that controls the operation of the telescopic motors 28, 34.

In Figure 4, the pressure sensor 36 generally comprises a resiliently deformable foam web 44 sandwiched between a pair of flexible polymeric support webs 46. The foam web 44 has a series of elongate through apertures 48 therein exposing the inner surface 50 of the support webs 46 that have an electrically conductive, copper coating thereon. The support webs 46 each have projections 52 thereon that project partially into the apertures 48 of the foam web 44. The projections 52 of each support web 46 are aligned with one another and the apertures 48 in the foam web 44 such that there is only a small space between opposing projections 52.

A wire (not shown) is soldered to the electrically conducting surface of each support web 46 to form a normally open pressure switch.

A small amount of pressure applied to either support web 46 causes the foam web 44 to compress allowing opposing projections 52 to make electrical contact with one another thereby closing the pressure switch.

The pressure sensor 36 can be cut to length to suit the chair 10 geometry and wired into a control circuit of the chair 10 as described below.

To protect the sensor 36 from damage, and for aesthetic reasons, the sensor 36 can be wrapped in fabric and/or sewn into a seam of the chair. Since the pressure sensor 36 is flexible, it can conform to curved or straight chair geometries.

Referring now to Figure 5, the operation of the rising chair 10 previously described is controlled using a controller 53, which comprises a control module 54 which is connected, in use, to a mains power supply 56.

The control module 54 comprises a power converter for converting mains voltage to 24V DC. The control module has a series of DIN sockets for connecting the telescopic motors 26, 34 and the remote control 42 thereto. A safety interface 58 is located between the control module 54 and the remote control 42, into which the pressure sensors 36, 38, 40 are wired In a known rising chair, the remote control 42 plugs into the "remote" socket of the control module 54. However, in Figure 6, it can be seen that the safety interface 58 comprises a male DIN plug 60 that plugs into the "remote" socket of the control module 54. The remote control 42 is plugged, instead, into a female DIN socket 62 of the safety interface 58.

The safety interface 58 comprises two relays 64, 66 and two capacitors 68, 70 that are wired to the pressure sensors 36, 38 and the contacts of the DIN plug 60 and socket 62.

To lower the chair, a user presses the "down" button on the remote control 42, which closes a circuit between pins 1 and 3 of the socket 62.

Conversely, to raise the chair, a user presses the "up" button on the remote control, which closes a circuit between pins 1 and 2 of the socket 62.

When a user desires to lower the chair, he/she presses the "down" button on the remote control 42. If the first pressure sensor 36 is open, i.e. if there is no obstruction present, electrical current flows through the relay to pins 1 and 3 of the plug 60 and the chair lowers. However, if the first pressure sensor 36 is closed, i.e. if an obstruction is present, the capacitor 68 charges and the relay 64 energises thereby switching the relay 64 so that current now flows between pins 1 and 2 of the plug 60, thereby causing the chair 10 to rise. Once the obstruction has been cleared by raising the chair so that the pressure sensor 36 opens, the relay remains in the raise" position for a short time until the capacitor 68 has discharged.

Similarly, to recline the chair, a user presses the "recline" button on the remote control 42, which closes a circuit between pins 1 and 5 of the socket 62. Conversely, to move the chair to an upright position, a user presses the "sit up" button on the remote control, which closes a circuit between pins 1 and 4 of the socket 62.

When a user desires to move the chair to an upright position, he/she presses the "sit up" button on the remote control 42. If the second pressure sensor 38 is open, i.e. if there is no obstruction present, electrical current flows through the relay 66 to pins 1 and 4 of the plug 60 and the chair moves to an upright position. However, if the second pressure sensor 38 is closed, i.e if an obstruction is present, the capacitor 70 charges and the relay 66 energises thereby switching the relay 66 so that current now flows between pins 1 and 5 of the plug 60, thereby causing the chair 10 to recline. Once the obstruction has been cleared by reclining the chair so that the pressure sensor 38 opens, the relay 66 remains in the "recline" position for a short time until the capacitor 70 has discharged The third sensor 40 in the seat portion 18 of the chair is similarly wired into the safety interface 58 such that the chair will not lower unless a person or object is sensed to be present on the chair.

Claims

Claims: 1. An articulated chair comprising: a base, a chair portion

movable relative to the base, an actuator for moving the movable chair portion between first and second positions, a control means for controlling the operation of the actuator, and at least one sensor affixed to the chair and operatively connected to the controller for sensing the presence of an obstruction, wherein the at least one sensor and controller are together arranged to stop and/or reverse the actuator when the presence of an obstruction is sensed.
2. An articulated chair as claimed in claim 1, wherein the movable chair portion comprises any one or more of the group comprising: a support frame of the chair, a seat portion of the chair, a backrest portion of the chair, and a footrest portion of the chair.
3. An articulated chair as claimed in claim 2, wherein at least one sensor is arranged to sense the presence of an obstruction located between the floor, and any one or more of the support frame, seat portion, or footrest portion of the chair.
4. An articulated chair as claimed in claim 3, wherein at least one sensor is affixed to the underside of the chair for sensing the presence of an obstruction beneath the chair.
5. An articulated chair as claimed in claim 2, wherein at least one sensor is affixed to the rear of the footrest and/or between the seat portion and the backrest portion of the chair.
6. An articulated chair as claimed in claim 2, wherein at least one sensor is located within the seat portion as is arranged to sense the presence of a person sitting on the chair.
7. A safety interface for an articulated chair, the articulated chair comprising: a control module connectable to a power supply, at least one actuator for articulating the chair; and a user interface operatively connectable to the control module for controlling the operation of the at least one actuator; wherein the safety interface is connectable between the user interface and the control module and is adapted to override the user interface when an unsafe condition is sensed by one or more sensors.
8. A safety interface as claimed in claim 7, wherein the safety interface is connectable between the user interface and the control module.
9. A safety interlace as claimed in claim 7 or claim 8, further comprising a
10. A safety interlace as claimed in claim 9, wherein one or more of the sensors is wired to, and arranged to effect switching of, the relay.
11. A safety interlace as claimed in claim 9 or claim 10, further comprising a capacitor wired in parallel with at least one of the sensors for delaying the switching of the relay.
12. A safety interlace as claimed in any of claims ito 11, wherein anyone of the control module, actuator, user interlace and sensor is connectable to any another of the control module, actuator, user interlace and sensor using a plug and socket
13. A controller for controlling the operation of an articulated chair, the controller comprising: a control module connectable to a power supply; at least one actuator for articulating the chair a user interlace operatively connectable to the control module for controlling the operation of the at least one actuator and a safety interlace adapted to ovemde the user interlace when an unsafe condition is sensed by one or more sensors
14. A controller as claimed in claim 13, wherein the safety interface is connectable between the user interface and the control module.
15. A controller as claimed in claim 13 or claim 14, further comprising a relay.
16. A controller as claimed in claim 15, wherein one or more of the sensors is wired to, and arranged to effect switching of, the relay.
17. A controller as claimed in claim 15 or claim 16, further comprising a capacitor wired in parallel with at least one of the sensors for delaying the switching of the relay.
18. A controller as claimed in any of claims 13 to 17, wherein any one of the control module, power supply, actuator, user interface, safety interface and sensor is connectable to any another of the control module, power supply, actuator, user interface, safety interface and sensor using a plug and socket.
19. An articulated chair, safety interface or controller as claimed in any preceding claim, wherein the sensor comprises a pressure sensor.
20. An articulated chair, safety interface or controller as claimed in claim 19, wherein the pressure sensor comprises first and second resiliently deformable webs each having at least one electrically conductive surface, the webs being maintained in a spaced apart relationship but being deformable so as to bring the electrically conductive surfaces into contact with one another.
21. An articulated chair, safety interface or controller as claimed in claim 20, further comprising an apertured, resiliently compressible web located between the first and second webs.
22. An articulated chair, safety interface or controller as claimed in claim 21, wherein at least one of the first and second webs comprises a plurality of projections that project at least partially into the apertures of the resiliently compressible web, the projections being arranged so as to reduce the separation between opposing conductive surfaces of the first and second webs.
23. An articulated chair, safety interface or controller as claimed in any preceding claim, wherein the actuator comprises a telescopic actuator.
24. An articulated chair, safety interface or controller as claimed in claim 23, wherein the telescopic actuator comprises an electric motor.
25. An articulated chair substantially as hereinbefore described with reference to and as illustrated in Figures 1, 2 and 3 of the accompanying drawings
26. A safety Interface substantially as hereinbefore described, with reference to and as illustrated in Figures 5 and 6 of the accompanying drawings.
27. A controller substantially as hereinbefore described, with reference to and as illustrated in Figures 4, 5 and 6 of the accompanying drawings.