GB2367808A

GB2367808A - A stairlift assembly

Info

Publication number: GB2367808A
Application number: GB0019563A
Authority: GB
Inventors: Peter James Tasker; Robert Alan Menear
Original assignee: Sunrise Medical Ltd
Current assignee: Sunrise Medical Ltd
Priority date: 2000-08-10
Filing date: 2000-08-10
Publication date: 2002-04-17
Anticipated expiration: 2020-08-10
Also published as: GB2367808B; GB0019563D0

Abstract

A stairlift assembly includes a carriage moving along a track, the footrest of the carriage including an obstruction sensing plate 24 which moves relative to the footrest on contacting an obstruction to operate one of four microswitches 23a-d by means of a post 25, operation of a microswitch causing the carriage to be stopped. An actuator may cooperate with a tab 13 on the footrest to raise the footrest. Alternatively, the actuator may act on the footrest via a coil spring (34) so that if movement of the footrest is obstructed, the movement of the actuator is absorbed by the spring (figure 7, not shown). The footrest and seat may be mounted on plate adjustably mounted on the carriage whereby the positions of the seat and footrest may be adjusted together relative to the carriage (figure 8, not shown).

Description

Title: A carriage for a stairlift assembly, and a stairlift assembly.

Description of Invention This invention relates to a carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, and to a stairlift assembly of this general kind.

Stairlift assemblies of this general kind are used, for example, by the elderly or infirm to assist them in negotiating a flight of stairs, and typically comprise a track which is mounted on or secured to one side of the stairs, and a carriage which is moveable relative to the track, with the carriage supporting a seat part on which the user is positioned when the assembly is in use.

It is an object of the present invention to provide an improved carriage and stairlift assembly of this general kind.

In accordance with a first aspect of the present invention, there is provided a carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, part of the carriage having sensing means adapted to sense an obstruction in the path of the carriage, the sensing means being moveable relative to said part.

The sensing means may be attached to or integral with a footrest of the carnage. Conveniently, resilient biasing means are operatively disposed between the footrest and the sensing means.

The sensing means may comprise a sensor plate, and the sensor plate may be suspended, conveniently resiliently suspended, from the footrest.

In this way, the sensor plate is able to move, to a limited extent, relative to the footrest.

The sensor plate may be provided with an actuator member, which, when the sensor plate comes into contact with an obstruction, is moved towards a trigger member on the footrest.

The actuator member may be moveable in a plurality of different directions relative to the footrest, and a plurality of trigger members may be provided on the footrest.

The actuator member may comprise a protrusion such as a pin, and the trigger members, which may comprise switches such as micro-switches, may be disposed, in use, around a distal end of the protrusion.

The trigger members may be provided in a recess of the footrest, and the protrusion may extend at least part-way into the recess.

The sensing means may be attached to the footrest in a snap-fitting manner, and the sensing means may be generally planar and lie, in use, in a plane which is substantially parallel to that of the footrest.

The footrest may be formed from a moulded plastics material, and the footrest may be moveable between an operative, generally horizontal position, and an inoperative, stowed position.

Powered operating means may be provided to effect said movement of the footrest.

In accordance with a second aspect of the present invention, there is provided a stairlift assembly having a track and a carriage which is moveable relative to the track, part of the carnage having sensing means adapted to sense an obstruction in the path of the carriage, the sensing means being moveable relative to said part.

The invention, in its second aspect, may comprise one or more of the features of the first aspect of the invention.

In accordance with a third aspect of the present invention, there is provided a carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, the carriage having a footrest which is powered so that powered movement thereof may be effected by a user.

An operating member of the carriage may bear upon a bearing part of the footrest, pressure exerted on said bearing part by said operating member effecting angular movement of the footrest.

The bearing part may be resiliently moveable relative to the footrest.

Conveniently, the bearing part is resiliently biased away from a plane of the footrest. The bearing part may be resiliently biased upwardly away from the plane of the footrest.

The resilience of the bearing part is preferably such that substantially no deformation thereof occurs during unobstructed angular movement of the footrest, but such that some resilient deformation thereof may occur when angular movement of the footrest is obstructed.

The resilience may be provided by a coil spring, coiled about the axis of a shaft about which the footrest is angularly moved.

In accordance with a fourth aspect of the present invention, there is provided a stairlift assembly having a track and a carriage which is moveable relative to the track, the carriage having a footrest which is powered so that powered movement thereof may be effected by a user.

The invention in its fourth aspect may comprise one or more of the features of the first, second or third aspects.

In accordance with a fifth aspect of the present invention, there is provided a carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, the carriage having a mounting member, a seat part and a footrest, the seat part and footrest being attached to or integral with the mounting member, and the mounting member being adjustable whereby its position relative to a stairway on which the track is mounted may be varied.

The mounting member, which may be generally planar, may be moveable relative to a track engaging part of the carriage. This movement may be substantially horizontal.

The mounting member may be adjustably attached to the track engaging part by a fastener extending through a generally elongate aperture in the mounting member. The aperture may comprise a slot, and at least two slots may be provided.

In accordance with a sixth aspect of the present invention, there is provided a stairlift assembly having a track and a carriage which is moveable relative to the track, the carriage having a mounting member, a seat part and a footrest, the seat part and footrest being attached to or integral with the mounting member, and the mounting member being adjustable whereby its position relative to a stairway on which the track is mounted may be varied.

The invention in its sixth aspect may comprise one or more of the features described in relation to the first, second, third, fourth or fifth aspects.

The invention will now be described in greater detail, but by way of example only, by reference to the accompanying drawings, wherein Figure 1 is a side view of a footplate ; Figure 2 is a top plan view of the footplate; Figure 3 is an underneath plan vie\\ of the footplate ; Figure 4 shows the footplate of Figure I with a sensor plate ; Figure 5 is a top plan view of the footplate and sensor plate ; Figure 6 is a top plan view of the footplate and the sensor plate, with the sensor plate being shown in two different displaced positions ; Figure 7 is a side view of the footplate, showing how it undergoes powered movement ; Figure 8 is a schematic side view of a carriage for a stairlift assembly; and Figure 9 is a schematic view of that part of the carriage which engages a track of the stairlift assembly.

Referring first to Figure 1, there is shown a footrest in the form of a footplate 10 for a stairlift assembly (not shown) of the type which is used, for example, by the elderly or infirm to assist them in negotiating a flight of stairs.

The footplate is moveable about a pivot axis 11, so that the footplate may be moved between an operative, generally horizontal position, as shown in Figure 1, and an inoperative, stowed position, in which a support part 12 is generally vertically orientated. The footplate 10, which in this example is moulded from a plastics material, is provided with a bearing part in the form of a rearwardly extending lug 13, a distal end 14 of which extends past the axis 11, such that downward pressure on the distal end 14 effects generally anticlockwise movement of the footplate 10 in the direction shown generally by the arrow B. The footplate 10 is provided with four downwardly extending catches 15 (two of which are shown in Figure 1), the catches 15 having barbs 16 which enable snap-fitting engagement of the catches with resilient parts of a sensor plate 24, as shown in Figures 4 to 6.

The footplate 10 also carries five rollers 17, the rollers 17 being rotatable about a generally horizontal axis, to facilitate sliding movement of the sensor plate 24 relative to the footplate 10.

As shown in Figure 2, the lug 13 is positioned between a pair of z : C > attachment formations 18, each of which being provided with a bore 19, through which extends an axle (not shown) about which the rotation of the footplate 10 occurs.

Figure 3 shows the moulded plastics configuration of the footplate 10 in more detail. The underside 20 of the footplate 10 is provided with a plurality of intersecting strengthening ribs 21, with the ribs 21 defining a generally centrally located recess 22 in which are located four trigger members in the

form of microswitches 23a, 23b, 23c and 23d. The microswitches 23a to 23d are connected to an electronic control means provided on the carriage of the stairlift assembly, activation of any of the microswitches being operative to activate cut-out circuitry within the motor assembly which drives the carriage, such that movement of the carriage relative to the track is halted. Although not shown in the drawings, connection of the microswitches 23a to 23d to the electronic control means may be effected through a plurality of wires or leads which extend within, or are attached to, the formations 18.

Figure 4 shows, in side view, the footplate 10 having attached thereto, in snap-fitting manner, a generally planar sensor plate 24, the barbs 16 of the footplate 10 extending into appropriately configured apertures on the sensor plate 24, which may also be formed from a moulded plastics material. To allow movement of the sensor plate relative to the footplate, upstanding parts 15a of the catches 15 are flexible.

An actuator member in the form of a pin 25 extends from an upper surface 26 of the sensor plate, a distal end 27 of the pin 25 extending into the recess 22 formed within the footplate 10. As shown in Figure 4, the pin 25 is thus located in close proximity to the microswitches 23a to 23d (of which only 23b and 23d are shown in Figure 4) such that movement of the sensor plate 24 relative to the footplate 10, in a generally horizontal plane, will bring part of the pin 25 into engagement with one or more f the microswitches 23, thus causing the aforementioned cut-out circuitry to operate.

As shown in Figure 5, the outer edge 28 of the sensor plate 24 extends beyond the periphery 29 of the footplate 10, with return springs 30 being positioned therebetween, such that the sensor plate 24, during normal use, is always biased towards the position shown in Figure 5. Referring next to Figure 6, this shows the sensor plate 24 in two different positions 24a and 24b, the

displaced positions 24a and 24b corresponding to contact of the sensor plate with obstructions located generally at X and Y respectively. As shown, engagement of the sensor plate 24 with an obstruction disposed generally at X C) ID causes the sensor plate to be moved rearwardly relative to the footplate, to the position shown in dotted outline at 24a. This movement also causes rearward movement of the pin 25 which is thus caused to adopt the position 25a at which it comes into contact with mircoswitch 23d, closure of the microswitch 23d effecting operation of cut-out circuitry which ceases further movement of the footplate towards the obstruction X. Similarly, engagement of the sensor plate 24 with an obstruction generally indicated at Y will shift the sensor plate to the position shown at 24b, such that the pin 25 adopts the position shown at 25b at which it engages microswitch 23c, whereupon the cut-out circuitry is caused to operate.

Upon removal of the obstacles X and Y, the return springs 30 are effective to bring the footplate 24 back to its rest position (shown in Figure 5), thus resetting the previously actuated microswitch, for subsequent re-use.

Whilst it will be appreciated that obstacles are most likely to be encountered during an ascent or a descent of a flight of stairs, meaning that displacement of the sensor plate 24 is most likely to occur as a result of obstacles at Y or Y', it is envisaged that the seat assembly to which the footplate 10 is mounted may be powered for rotational movement, such that limited rotational movement of the footplate 10 in the plane of Figures 5 and 6, for example, may be permitted. During such movement, obstructions could be encountered, and it will be appreciated that under such circumstances, displacement of the sensor plate 24 could occur in a direction such that

actuation of the microswitches 23b or 23d could occur.

Referring next to Figure 7, this shows, in side view, an alternative construction of footplate in which the lug 13 of Figures 1 to 6 is replaced with a coil spring 31, one end 32 of which is attached securely to the attachment formation 18 of the footplate 10 between a pair of retaining members 33.

The other end 34 of the coil spring 31 extends from the attachment C > formation 18 and is borne upon by a hydraulic or solenoid-actuated piston 35 which is mounted to the carriage of the assembly in such a manner as to permit reciprocating movement as indicated by the arrow A.

The stiffness of the coil spring 31 is relatively high, such that downward movement of the piston 35 results directly in anticlockwise rotation of the footplate 10 in the direction generally shown by the arrow B. In particular, in view of the stiffness of the coil spring 31, the angle between the end 34 of the coil spring 31 relative to the upper surface 12 of the footplate 10 remains substantially unchanged during the rotational movement of the footplate 10 in the direction of the arrow B. In practice, therefore, during unobstructed

movement of the footplate 10, the distal end 34 of the coil spring 31 acts as a generally rigid lug extending from the attachment formation 18.

However, should movement of the footplate 10 in the direction of the arrow B be obstructed by an obstruction Z, meaning that the footplate 10 cannot continue to rotate in the direction of the arrow B, continued downward movement of the piston 35 results in elastic deformation of the coil spring 31 such that the distal end 34 is caused to bend towards the positions shown in dotted outline at 34a and 34b. In this the pneumatic motor or solenoid driving the piston 35 does not become overburdened, which might otherwise result in trip circuitry coming into operation, as continued travel of the piston 35 is permitted, albeit with some resistance from the coil spring 31.

Upon removal of the obstruction Z, the potential energy stored within the coil spring 31 is effective to allow continued rotational movement of the footplate 10, with the distal end 34 of the coil spring 3) simultaneously returning to its rest position, shown in solid outline in Figure 7.

Figure 8 shows, in schematic form. part of a stairlift assembly having an extruded track 40 and a carriage 41 which is moveable relative to the track 40 by engagement of a powered pinion 42 with a rack (not shown) which is disposed just behind a protective lip of the track 40. The carriage comprises a track engaging part 44 and a mounting member in the form of a mounting plate 45 which is provided with a pair of elongate apertures 46. The mounting plate 45, defined by side edges 45a, 45b, 45c and 45d is slidable relative to the track engaging part 42 in the direction shown by arrow C such that the distance therefrom to the stairs (positioned in the region generally shown at"S") may be varied.

So as to ensure that no offset occurs between the footplate 10 and the seat assembly 47 during adjustment of the mounting plate 45, the seat assembly 47 and the footplate 10 are both mounted to the common mounting member 45, as is a pivot axle 48 about which the seat assembly 47 may rotate.

Securement of the mounting member 45 in a desired position is effected by tightening bolts 49, with the bolts 49 having heads 50 which are slightly larger than the apertures 46.

Referring finally to Figure 9, this shows in more detail the track engaging part 44 of the carriage 41, with the track engaging part comprising a body 50 and a downwardly depending support plate 51, the support plate 51 having a pair of apertures 52 therein. A pair of generally vertically orientated rollers 53 are mounted for rotational movement relative to a lower part of the support plate 51, and a pair of perpendicularly orientated rollers 54 are constrained partly within the apertures 52 for rotation about a generally vertical axis. The support plate 51 is attached to the body 50 via four screw-threaded fasteners 55, each of which is provided with an Allen head 56 which facilitates easy removal of the fasteners 55. Thus, should it be desired to clean or replace the rollers 53 and 54, all that is required is the removal of four screw-threaded fasteners 55, in contrast to the previous proposals, which have required inconvenient deconstruction of individual roller mountings.

In the present specification"comprise"means"includes or consists of and"comprising"means"including or consisting of'.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS: 1. A carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, part of the carriage having sensing means adapted to sense an obstruction in the path of the carriage, the sensing means being moveable relative to said part.
2. A carriage according to claim I wherein the sensing means is attached to or integral with a footrest of the carriage.
3. A carriage according to claim 2 wherein resilient biasing means are operatively disposed between the footrest and the sensing means.
4. A carriage according to claim 1, claim 2 or claim 3 wherein the sensing 0 means comprises a sensor plate.
5. A carriage according to claim 4 wherein the sensor plate is suspended from the footrest.
6. A carriage according to claim 4 or claim 5 wherein the sensor plate is provided with an actuator member, which, when the sensor plate comes into contact with an obstruction, is moved towards a trigger member on the footrest.
7. A carriage according to claim 6 wherein the actuator member is 0 z : moveable in a plurality of different directions relative to the footrest, and wherein a plurality of trigger members is provided on the footrest.
8. A carriage according to claim 7 wherein the actuator member comprises a protrusion, the trigger members being disposed, in use, around a distal end of the protrusion.
9. A carriage according to claim 7 or claim 8 wherein the trigger members are provided in a recess of the footrest, and wherein the protrusion extends at least part-way into the recess.
10. A carriage according to any one of claims 2 to 9 wherein the sensing means is attached to the footrest in a snap-fitting manner.
11. A carriage according to any one of claims 2 to 10 wherein the sensing means is generally planar and lies, in use, in a plane which is substantially parallel to that of the footrest.
12. A carriage according to any one of claims 2 to 11 wherein the footrest is formed from a moulded plastics material.
13. A carriage according to any one of the preceding claims wherein the footrest is moveable between an operative, generally horizontal position, and an inoperative, stowed position.
14. A carriage according to claim ! 3 wherein powered operating means is I I provided to effect said movement of the footrest.
15. A stairlift assembly having a track and a carriage which is moveable

relative to the track, part of the carriage having sensing means adapted to sense 0 C) an obstruction in the path of the carriage, the sensing means being moveable relative to said part.
16. A stairlift assembly according to claim 15 comprising one or more of the features set out in claims 1 to 14.
17. A carriage for a stairlift assembly of the kind having a track relative to

which the carriage is moveable, the carriage having a footrest which is powered 0 so that powered movement thereof may be effected by a user.
18. A carriage according to claim 17 wherein an operating member of the

carnage bears upon a bearing part of the footrest, pressure exerted on said r > bearing part by said operating member effecting angular movement of the footrest.
19. A carnage according to claim 18 wherein the bearing part is resiliently moveable relative to the footrest.
20. A carriage according to claim 19 wherein the bearing part is resiliently

biased away from the plane of the footrest.
21. A carriage according to claim 19 or claim 20 wherein the resilience of the bearing part is such that substantially no deformation thereof occurs during unobstructed angular movement of the footrest, but such that resilient deformation thereof may occur when angular movement of the footrest is obstructed.
22. A carriage according to claim 19, claim 20 or claim 21 wherein the resilience is provided by a coil spring, coiled about the axis of a shaft about which the footrest is angularly moved.
23. A stairlift assembly having a track and a carriage which is moveable relative to the track, the carriage having sensing means adapted to sense an obstruction in the path of the carriage, the sensing means being moveable relative to said part.
24. A stairlift assembly according to claim 23, further comprising one or more of the features set out in claims 1 to 22.
25. A carriage for a stairlift assembly of the kind having a track relative to which the carriage is moveable, the carriage having a mounting member, a seat part and a footrest, the seat part and footrest being attached to or integral with the mounting member, and the mounting member being adjustable whereby its position relative to a stairway on which the track is mounted may be varied.
26. A carriage according to claim 25 wherein the mounting member is moveable relative to a track engaging part of the carriage.
27. A carriage according to claim 26 wherein the movement is substantially horizontal.
28. A carriage according to claim 26 or claim 27 wherein the mounting member is adjustably attached to the n-ack engaging part by a fastener

extending through a generally elongate aperture in the mounting member.

0
29. A carriage according to claim 28 wherein the aperture is a slot.
30. A carriage according to claim 28 or claim 29 wherein at least two slots are provided.
31. A stairlift assembly having a track and a carriage which is moveable relative to the track, the carriage having a mounting member, a seat part and a footrest, the seat part and footrest being attached to or integral with the mounting member, and the mounting member being adjustable whereby its position relative to the stairway on which the track is mounted may be varied.
32. A stairlift assembly according to claim 31 further comprising one or more of the features set out in claims 1 to 30.
33. A carriage substantially as hereinbefore described and/or as shown in the accompanying drawings.
34. A stairlift assembly substantially as hereinbefore described and/or as shown in the accompanying drawings.
35. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.