IMPROVEMENTS IN OR RELATING TO STAIRLIFTS

Field of the Invention

This invention relates to stairlifts and, in particular, to a control for a stairlift.

Background to the Invention

Conventional forms of stairlift control include a pair of push buttons or a bidirectional joystick to control movement of the stairlift carriage along the stairlift rail. For reasons of safety these, and indeed other known forms of stairlift control, require the application of a constant directed manual pressure both to establish the direction of motion of the carriage, and also to maintain power to the motor which drives the carriage along the rail. Once this manual pressure is released, the stairlift comes to a halt.

For stairlift users having limited manual dexterity, maintaining this directed constant pressure, so as to maintain the direction of motion as well as to effect movement of the stairlift, can be awkward and even painful.

It is an object of the invention to provide a method of controlling a stairlift and/or a control system for a stairlift which will go at least some way in addressing the aforementioned problems; or which will at least provide a novel and useful choice.

Summary of the Invention

Accordingly, in a first aspect the invention provides a control for a stairlift, said control being actuable to effect movement of a stairlift carriage along a stairlift rail, said control being characterised in that it has separate elements to effect movement of said carriage and to determine the direction of movement of said carriage.

Preferably said control is further characterised in that said control comprises a first control element to establish the direction of movement of said carriage on said rail, and a second control element to initiate and maintain movement.

Preferably said first control element is constructed and arranged to react to a onetime signal command. This signal command may, for example, be a physical input, a voice input, or may derive from an electrical or electronic signal dependent on the last direction of travel of said carriage. In the latter case, the direction input may simply be the reverse of the direction in which the carriage was last moving.

In a second aspect the invention provides a stairlift control to control the movement of a stairlift carriage along a stairlift rail, said control being characterised in that it includes a motion element reactive to pressure applied by a user, and a direction-determining element responsive to said motion element according to the last direction of movement of said carriage.

Preferably said direction-determining element is operable to reverse the direction of movement of said carriage in successive actuations of said motion element.

Preferably said stairlift further includes a chair supported on said carriage; and an occupancy sensor operable to sense the presence of a user in said chair, said stairlift control being operable only when said occupancy sensor indicates the presence of a user.

In a third aspect the invention comprises a stairlift control to control the movement of a stairlift carriage in a particular direction on a stairlift rail, said control being characterised in that it includes a first element responsive to a onetime command to establish said direction; and a second element responsive to the application of constant pressure to maintain movement of said carriage.

Preferably said first element is responsive to a physical input, a voice input, or may derive from an electrical or electronic signal dependent on the last direction of travel of said carriage.

Many variations in the way the present invention can be performed will present themselves to those skilled in the art. The description which follows is intended as an illustration only of one means of performing the invention and the lack of description of variants or equivalents should not be regarded as limiting. Wherever possible, a description of a specific element should be deemed to include any and all equivalents thereof whether in existence now or in the future. The scope of the invention should be limited by the appended claims alone.

Brief Description of the Drawing

One preferred form of the invention will now be described with reference to the accompanying drawing in which:

Figure 1 : shows an isometric view of a stairlift incorporating a control according to the invention.

Detailed Description of Working Embodiment

Referring to the drawing, the present invention provides a control for a stairlift 5 which includes a rail 6, a carriage 7 mounted on the rail for movement there- along, and a chair 8 supported on the carriage 7. The chair includes armrests 9a and 9b, and a seat 10. In the conventional manner, the carriage includes a drive motor and gearbox (not shown) operable to drive the carriage up and down the rail 6.

Conventional stairlift operating controls require the application of directed manual pressure. That is to say, the application of constant manual pressure against spring resistance generated by the control itself. Generally an operating force must be maintained so as to indicate the required direction of travel and thus the control must provide for two different operating modes - one for up and one for down — in addition to the idle or off mode when the control is released. This can prove awkward and even painful, particularly for stairlift users having impaired manual dexterity.

The present invention seeks to address the problems inherent in conventional controls by separating out the determination of direction and allowing carriage movement to be maintained simply by the weight of the user' s hand, forearm or other suitable body part.

In the form shown in Figure 1 a physical input device, such as a simple projecting lever 12 mounted on armrest 9b, may be provided to establish carriage direction. In use, a user applies a one-time command by simply nudging the lever 12 in the desired direction of travel, and can thereafter leave the lever 12 untouched. Alternatively the user could give a one-time voice command, the command being picked up by microphone 14 and relayed to a suitable form of voice-activated control unit (not shown) incorporated in the carriage 7. As yet a further alternative the controls 12 and/or 14 could be omitted altogether and the direction of the carriage established electrically or electronically according to a protocol influenced according to the last direction of travel of the carriage, and possibly also taking into account the position of the carriage on the rail. In its most simple embodiment, this protocol would simply reverse the direction of travel of the carriage at each successive application of the motion control.

Many alternatives to the lever 12 can be envisaged to provide a physical input. By way of example only, a control similar to a computer mouse could be provided, the device being configured so that, say, one click could cause the stairlift to move in the upward direction, whilst two clicks could cause the stairlift to move in the downward direction. Further, such a control could be combined with the rationale of the third option described above, so that successive clicks would reverse the direction of the stairlift.

In the particular embodiment illustrated, the motion control comprises a pad 16 incorporated in arm rest 9a. Once the direction of motion has been established, motion is initiated and maintained simply by resting the hand or forearm on pad 16. If the hand or forearm is removed from pad 16, the carriage comes to a halt.

It will be appreciated by those skilled in the art that hand/arm operated controls are the norm for stairlifts but the present invention envisages other forms of control which may have a pressure applied thereto by other parts of a user's body.

The order in which control elements 12 or 14, and 16 are operated, is not an essential feature of the invention. The directional command may be given first and then pressure applied to the pad 16. In this event, the directional command must be held in short term memory (say 5 - 10 seconds) so that it is not lost before the user applies pressure to pad 16 to set the carriage in motion.

Alternatively the user applies pressure to pad 16 with one hand/arm and then nudges control 12 or voices a direction command thereafter.

The control system as above described preferably operates in conjunction with an occupancy sensor 18 included in the chair 8. This prevents inadvertent operation of the stairlift whilst a user is moving in and out of the chair, during which time pressure may be applied to pad 16 for support.

It will thus be appreciated that the present invention provides a simple yet effective form of control for a stairlift installation which can easily be operated by persons having severely impaired manual dexterity.