WO1997045354A1

WO1997045354A1 - Stairlift

Info

Publication number: WO1997045354A1
Application number: PCT/GB1997/000851
Authority: WO
Inventors: John Edric Bovis
Original assignee: Stannah Stairlifts Limited
Priority date: 1996-05-31
Filing date: 1997-03-26
Publication date: 1997-12-04
Also published as: GB9611429D0

Abstract

A stairlift assembly comprises a rail (10) for mounting along a flight of stairs and is provided with a toothed rack (12) along its upperside: a seat carriage (2) runs along the rail (10), the seat carriage including a motor which drives a toothed pinion wheel (22) engaged with the rack (12). A flexible belt (3) runs lengthwise of the rail below the rack (12), around guides (18) at the opposite ends of the rail and then along the upperside of the rail from its opposite ends to cover the rack, the opposite ends of the belt (30) being attached to opposite ends of the carriage (20).

Description

STAIRLIFT

The present invention relates to stairlifts and more particularly to a stairlift assembly which includes a cover arrangement for the toothed rack of the rail on which the stairlift chair runs. Typically, the chair of a stairlift is mounted to a carriage which runs on a rail, which is mounted along the flight of stairs and is provided with a toothed rack: the carriage includes a motor which drives a toothed pinion wheel engaged with the rack, in order to drive the carriage along the rail. Generally, the toothed rack is exposed and is often therefore unsightly and moreover liable to pick up household dust etc.

U.S. Patent No. 5,230,405 discloses a stairlift assembly in which the toothed rack is covered by a belt, the opposite ends of which are fixed at the opposite ends of the rail. The belt runs over an assembly of rollers within the carriage, to lift the belt above the toothed pinion wheel of the carriage: as the carriage moves along the rail, the stationary belt is deflected up and through the assembly of rollers within the carriage, and finally back onto the rail. It will be appreciated however that this arrangement is complicated.

We have now devised a stairlift assembly in which the toothed rack is covered in a relatively simple but effective manner.

In accordance with the present invention, there is provided a stairlift assembly which comprises a rail for mounting along a flight of stairs and is provided with a toothed rack along its upperside, a seat carriage which runs on the rail and includes a motor which drives a toothed pinion wheel engaged with said rack, and a flexible belt which runs lengthwise of said rail below said rack, around guides at the opposite ends of the rail and then along the upperside of the rail from its opposite ends to cover said rack, the opposite ends of the belt being attached to opposite ends of said carriage. In use, it will be appreciated that as the carriage is driven along the rail, the belt is displaced longitudinally of itself, passing around the guide at one end of the rail from above the rack to below the rack and passing around the guide at the other end of the rail from below to above the rack.

Preferably the upperside of the rail is formed with a recess extending along its length, the toothed rack being positioned within this recess. The recess may accommodate other components or mechanisms which the carriage engages at particular positions along the rail, e.g. ramps to control the speed or stopping of the carriage adjacent the opposite ends of the rail, mechanical end stops, and charging terminals for the battery of the seat carriage. Preferably the flexible belt extends across the top of this recess to fully cover all of the components or mechanisms, which are accommodated in the recess: this is a further distinction over U.S. Patent No. 5,230,405, in which the belt covers the rack only and would be difficult to modify to also cover mechanisms positioned within the rail.

Preferably the rail includes flat, longitudinal surfaces either side of the recess, on which the opposite edge portions of the belt run.

Preferably the belt runs through a hollow interior space of the rail, below the rack. Preferably the guides at the opposite ends of the rail comprise fixed elements having curved surfaces over which the belt slides.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

FIGURE 1 is a schematic longitudinal sectional view of a stairlift assembly in accordance with the present invention; and

FIGURE 2 is an enlarged cross-section through the rail of the assembly shown in Figure 1.

Referring to Figure 1, a stairlift assembly comprises a rail 10 which is mounted along the stairs (not shown) and provided with a toothed rack 12 extending along its length. A carriage 20, shown schematically, is mounted across the rail 10 for movement along the latter, and a chair (not shown) is mounted to the carriage. A drive motor is also mounted to the carriage 20 and drives a toothed pinion wheel 22, which is meshed with the rack 12, to drive the carriage 20 along the rail.

A particular form of rail 10 is shown in Figure 2. This example is of generally rectangular, hollow cross-section, with a pair of flanges 11 projecting from its opposite sides, between which flanges support rollers 24 of the carriage 20 run. Additional flanges 13 project from the opposite sides of the rail along its bottom face, to form grooves 14 into which brackets (not shown) engage for mounting the rail to the stairs. The upper side of the rail 10 is formed with a wide recess 15 and the rack 12 is mounted to the bottom of this recess, adjacent one side. A narrow flat margin 16 is provided either side of the recess 15 adjacent the upper flanges 11. As previously mentioned, additional components or mechanisms (e.g. for stopping the carriage adjacent the opposite ends of the rail 10 and/or battery charging terminals) may be mounted to the floor of the recess 15.

The recess 15 of the rail 10 is closed by a flexible belt 30, the opposite longitudinal edge portions of this belt being supported on the flat margins 16 either side of the recess 15. In particular, the belt 30 runs through the hollow interior of the rail 10, around curved guides 18 fitted to the opposite ends of the rail 10 (Figure 2), and along the upperside of the rail from the opposite ends of the latter, until it reaches the carriage 20: the opposite ends of the belt are secured to the opposite ends of the carriage; preferably the carriage 20 includes an arrangement 26 for tensioning the belt 30. As the carriage 20 is driven along the rail 10, the belt 30 is displaced along its own length, being guided at one end of the rail over the respective guide 18 from the upperside of the rail to the underside of the rail, and at the same time being guided at the other end of the rail over the other guide 18 from the underside of the rail to its upperside. The belt 30 runs smoothly on the margins 16 either side of the recess 15, and also runs smoothly over the curved guides 18 and over the underside of the rail.

It will be appreciated that the belt 30 covers the recess 15, and hence the rack 12 and the other components or mechanisms disposed within the recess 12, in an effective and relatively straightforward manner.

Claims

1) A stairlift assembly which comprises a rail for mounting along a flight of stairs and provided with a toothed rack along its upperside, a seat carriage which runs on the rail and includes a motor which drives a toothed pinion wheel engaged with said rack, and a flexible belt which runs lengthwise of said rail below said rack, around guides at the opposite ends of said rail and then along the upperside of said rail from its opposite ends to cover said rack, the opposite ends of said belt being attached to opposite ends of said carriage.

2) An assembly as claimed in Claim 1, wherein the upperside of said rail is formed with a recess extending along its length, said toothed rack being positioned within said recess.

3) An assembly as claimed in Claim 2, wherein said recess accommodates additional components or mechanisms which said carriage engages at particular positions along said rail.

4) An assembly as claimed in Claim 3, wherein said flexible belt extends across the top of said recess to fully cover all of the components or mechanisms contained therein.

5) An assembly as claimed in any of Claims 2 to 4, wherein said rail includes flat, longitudinal surfaces either side of said recess, on which the opposite edge portions of said belt run.

6) An assembly as claimed in any preceding claim, wherein said belt runs through a hollow interior space of said rail, below said rack.

7) An assembly as claimed in any preceding claim, wherein said guides at the opposite ends of said rail comprise fixed elements having curved surfaces over which said belt slides. 8) An assembly as claimed in any preceding claim, wherein said carriage comprises an arrangement for tensioning said belt.