Stairlifts

Abstract

A stairlift rail is configured to cause a stairlift carriage and chair to rotate a small amount in a downhill direction adjacent to the lower end of the rail, thus avoiding a clash between the chair and the staircase.

Claims

1. A unitary stairlift rail for fitment alongside a first edge of a staircase having an upper end and a lower end, wherein a line extending between said upper end and said lower end defines a slope of the staircase, the unitary stairlift rail comprising: an upper section to be aligned substantially parallel to the slope; a lower section extending from the upper section but angled downwardly with respect to the upper section and terminating at the lower end; and a junction between the upper section and the lower section, the unitary stairlift rail, when viewed from above in plan view, includes a bend defining an angle in a range of 5 to 20 between the upper section and the lower section.

2. The unitary stairlift rail according to claim 1, wherein the bend comprises at least part of the junction and is configured to also rotate the alignment of the unitary stairlift rail in a vertical plane.

3. The unitary stairlift rail according to claim 2, wherein the junction includes a second bend to further rotate the alignment of the unitary stairlift rail in the vertical plane.

4. The unitary stairlift rail according to claim 3, wherein the bend and the second bend are separated by a straight section of the unitary stairlift rail, and the straight section is angled downwardly with respect to the upper section.

5. The unitary stairlift rail according to claim 1, wherein the lower section is aligned substantially vertically.

6. A stairlift installation including the unitary stairlift rail according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The various aspects of the invention will now be described with reference to the accompanying drawings in which:

(2) FIG. 1: shows a side elevation of part of a stairlift rail according to the invention;

(3) FIG. 2: shows a view from above of that which is shown in FIG. 1;

(4) FIG. 3: shows a cross-section along the line 3-3 in FIG. 1;

(5) FIG. 4: shows an isometric view of part of a stairlift installation including a rail according to the invention; and

(6) FIG. 5: shows a plan view of part of a stairlift installation including a rail according to the invention.

DETAILED DESCRIPTION OF WORKING EMBODIMENT

(7) This invention relates generally to a stairlift 5 for installation on a staircase 6, the stairlift including a unitary rail 7 mounted along one edge 10 of the staircase, a carriage 8 mounted on the rail, and a chair 9 mounted on the carriage. As used herein unitary rail means a rail formed from one or more sections of a single substantially uniform cross-section, joined end-to-end to form a single running support and is thus to be distinguished from stairlift rails formed from two spaced tubes, both of which contribute to the support and guiding of the carriage. In the particular form shown and described, the rail is formed from one or more sections of round tube joined end to end and is substantially as described in our European Patent 1 720 790 (EP '790). To this end the rail comprises an upper section 11 aligned substantially with the slope of the staircase 6, and a lower section 12 formed integrally with the upper section 11 but angled downwardly with respect to the upper section 11 through a junction 13 between the two sections. A tang 14 extends along the underside of the rail, the tang including apertures 15 into which the teeth of a drive sprocket (not shown) can engage to drive the carriage along the rail. The tang 14, which on upper rail section 11 projects vertically downwards, also provides a support surface to prevent rotation of the carriage 8 about the rail axis.

(8) As described in EP '790 the lower section 12 terminates on the first tread 16 of the stairway, thereby minimizing or even eliminating the protrusion of the rail 7 at the lower end of the staircase. This then eliminates the need to provide a folding section or hinge at the lower end of the rail in order to avoid creating an obstruction at the foot of the rail.

(9) The chair 9 includes a seat base 17, a backrest 18, and a footrest 19.

(10) While the stairlift described in EP '790, is effective in eliminating the need for hinged or folded rail sections, with some stairlift geometries a problem can arise with the footrest 19 clashing with the staircase. This problem could be addressed in a number of ways by taking into account a number of factors including the relationship between rail height, the position of the pivot between the chair and the carriage, and the position of the footrest in relation to the staircase nosings. By way of example only, clashing could be avoided by pivoting the footrest 19 in a downhill direction relative to the remainder of the chair, by mounting the chair so that it is aligned in a downhill direction, and/or by substantially reducing the width of the footrest, however all of these solutions can negatively impact user safety and comfort and/or increase the complexity of the design. The clashing problem could also be addressed by other changes in configuration and/or geometry but any such changes would inevitably render the installation more bespoke or less standard. This is undesirable from a manufacturing viewpoint.

(11) The present invention therefore addresses the problem by configuring the rail in the manner such that, as the carriage moves from the upper rail section 11 to the lower section 12, it is rotated a small amount in a downhill direction (as indicated by arrow 20) thereby providing clearance between the footrest 19 and the staircase 6. This is achieved by providing shallow bend 21, the axis 23 of which, when viewed in plan as in FIG. 2, defines an angle with vertical plane 22 passing through edge 10 of the staircase when viewed in plan.

(12) It will be appreciated from FIG. 1 that bend 21 also increases the angle of the rail with respect to a horizontal plane. For example the bend 21 may increase the rail angle from (say) the 40 angle of the upper rail section 11 to around 65. A further bend 24 is then provided to rotate the rail further to the vertical orientation of the lower rail section 12.

(13) The bends 21 and 24 could conceivably be formed as one but, in the embodiment shown, are separated by a short straight section of rail 25.

(14) It will be appreciated that the tang 14 on the upper section 11 of rail will be oriented parallel to the plane 22 while the tang on bend 21 will be twisted through angle . The orientation of the tang on section 25, bend 24 and lower rail, section 12 is maintained at angle to the plane 22, a cross-section through the lower rail section 12 being shown in FIG. 3.

(15) Angle will generally (but not necessarily always) depend on the particular installation. For example is preferably in the range 5-20 and may be nearer the lower end of the range if a degree of protrusion of the rail section 12, beyond the tread 16, can be accommodated. The dimensions of the riser and tread widths may also influence the establishment of angle .

(16) It will thus be appreciated that the invention, at least in the case of the embodiment described here, is particularly advantageous in that if offers a stairlift rail design that eliminates clash between the chair and the staircase eliminated without the need to modify the chair or carriage in any way. Given that stairlift rails are invariably bespoke this reduces cost and significantly improves design and installation efficiency.