The invention relates to a stair rail for a stairlift and a support means for the stair rail. A stairlift is a mechanical device for lifting a person (or a load) up and/or down stairs. A rail is mounted adjacent to the stairs, and a moveable carrier (for example a platform or chair) is supported by the rail. The moving carrier is operable to support the weight of a person and to transport the person up and/or down the stairs by moving along the rail.

Since the rail has to support the weight of a person, it must be properly supported. The nature of a stairlift often means that the load is applied to the rail by a cantilever (e .g. a chair that is remote from the rail), which may require a pair of rails to react the torque . In order to provide support, rail systems are typically supported by stanchions : upright supports that transfer vertical loads from the rail to the floor or stair treads and which react any lateral loads arising from the cantilevered chair or platform.

The rail support system has to provide sufficient support to minimise flexing of the rail system under load, which may result in tilting of a support carrier that is carried by the rail. Such tilting may be alarming to the user because it may cause the carrier to tilt forward and make the user feel they may fall. A number of stanchions are typically used, positioned at intervals along the stairs.

The rail is typically required to run parallel to the stairs. Some stairs may have a non- uniform inclination: the tread height and/or tread depth may not be uniform. In addition, it may sometimes be necessary to provide a stanchion near an end of the rail. At the bottom of the stairs the rail may be relatively close to the floor, and at the top of the stairs the rail may be relatively far from the floor. For these reasons, it is often necessary to cut a set of stanchions for supporting a stair rail to appropriate lengths, so that they are suitable for supporting a rail at a uniform inclination. This may increase the cost of providing a stairlift, because it means that each stairlift must be manufactured or adapted specifically for each installation, rather than being provided as an ex-stock item. JP2000/128457 discloses an arrangement for allowing height adjustability of the support of a stairlift rail. Vertically oriented oblong holes are provided in plates connected to a pair of rails, which accommodate vertical adjustment of the height at which the rails are attached to a fixed height tapped hole in the stanchion. Lateral adjustment is accommodated by horizontally oriented oblong holes formed in brackets that secure the rail to the fixed height hole in the stanchion.

A number of problems exist with this approach. The nuts and bolts are unsightly, and visible to a user. Furthermore, a rather limited range of continuous adjustment is possible using the vertically oriented oblong slots. In order to extend the range of adjustment, more than one set of tapped holes are provided in the stanchion at different heights. This is unsatisfactory, because it is inconvenient to have two different height adjustment means, and because it leaves the unused external holes visible to the user.

An alternative means of adjusting the height at which a stairlift rail is fixable to a stanchion is desired. In addition, a means of adjusting the height at which a stairlift rail is fixable to a stanchion that overcomes at least some of the above mentioned problems is desired.

According to a first aspect of the invention, there is provided a stairlift system comprising a rail and a stanchion for supporting the stairlift rail. The stanchion comprises a foot, an upstanding member and fixing means. The foot comprises a bottom surface for resting on a floor. The upstanding member comprises a first and second element. The first element comprises a first end portion for coupling to the foot. The second element comprises a mount to which the stairlift rail is attachable. A distance between the mount and the first end portion is adjustable by moving the second element relative to the first element. The fixing means is operable to reversibly fix the first element to the second element so that the upstanding member can support a load applied to the mount by the rail, and the fixing means is configured to provide a continuous adjustment range of the distance.

The load may include the weight of a chair and a person, and may be at least 1000N, 1500N, 2000N or 3000N. The load may be substantially vertical (e.g. parallel with an axis of the upstanding stanchion). The continuous (as opposed to discontinuous) nature of the adjustment range means that the distance can conveniently be set to a specific height with accuracy. A stanchion with a moveable mounting provides an alternative arrangement for adjusting the height at which a rail may be supported. In contrast to the prior art, the height of a mount of the stanchion is variable, rather than using a mount at a fixed height and providing some adjustment of which location of a rail bracket is attached to a mount of a stanchion. The first and second element may be substantially tubular. This is a convenient shape for a load bearing element.

The first and second element may be at least partially concentric over an overlapping region, the distance being adjustable by varying the size of the overlapping region. Such an arrangement may have high strength and be straightforward to produce . The overlapping region enables the upright member to resist a bending moment.

The first element may be internal to the second element over the overlapping region. This is a convenient arrangement because it allows the fixing means to rest on the top of the first element.

The fixing means may comprise a gripper operable to provide reversible frictional engagement between the gripper element and one of the first or second element. The use of frictional engagement is a convenient means of reversible fixing that readily provides for a continuous range of adjustment of the distance . Reversible frictional engagement means that there is a first configuration of the gripper in which there is substantially no frictional engagement between the gripper and one of the first or second element, such that the length of the stanchion is freely adjustable, and a second configuration of the gripper in which the frictional engagement between the gripper and first or second element is capable of supporting the load.

In other embodiments the gripper may cause the first and second element to frictionally engage with each other by clamping them together. The gripper may be configured to mechanically engage with the other of the first and second element. For instance the gripper may rest on the other element (to that with which it reversibly frictionally engages) . In some embodiments the gripper may be fixed to the other element, for instance by a fastener, bonding or welding. The load from the rail may thereby be transferred via the mount, second element, gripper and first element to the foot (and thence, the floor).

The gripper may be configured to be positioned within the upstanding member and to frictionally engage with an interior surface of the upstanding member. Positioning the gripper within the upstanding member means that it is hidden from the user, making the stanchion look more attractive to a user.

The gripper may be configured to provide an interference fit with an interior surface of the first element. An interference fit may be a convenient way of retaining the gripper in engagement with the first element.

The gripper may comprise a first and second gripper element and a fastener for fixing the first and second gripper element together with a clamping force. The stairlift system may further comprise a spring element for applying a level of frictional engagement between the first and second element that is sufficient to support the weight of the second element, but which allows adjustment of the distance.

The first gripper element may comprise a first inclined face, and the second gripper element may comprise a second inclined face for sliding engagement with the first inclined face and a friction surface. The gripper may be configured such that the sliding engagement of the first and second inclined faces results in a movement of the friction surface in a direction transverse to the clamping force so as to bring the friction surface into engagement with the second element. The use of inclined faces enables a high lateral force to be achieved in response to clamping the first and second gripper elements together. This may result in a very secure fixing means that is easy and convenient to adjust.

The fastener may comprise a threaded element and the first gripper element may comprises a corresponding threaded feature for engagement with the threaded element, and the second gripper element comprises a clearance hole for receiving the fastener and configured to accommodate a relative movement of the first and second gripper elements lateral to an axis of the threaded hole when the first gripper element is attached to the second gripper element using the fastener. A threaded element is a convenient way to exert a clamping force. Other arrangements are possible, for example a cam may be used to clamp together the first and second gripping elements.

The threaded element may comprise a screw, and the corresponding threaded feature may comprise a tapped hole . The gripper may further comprise at least one washer, for example a plain washer. The spring element may comprise a disk spring for use under a head of the screw. The disk spring may apply pressure to the upper grip to cause a level of frictional engagement that is sufficient to support the weight of the second element, while still allowing a user to cause relative movement between the first and second element. In this way height adjustment of the stanchion may readily be achieved. Once an appropriate height has been selected, further torque may be applied to the screw to lock the first and second element together such that they may bear the load from the rail. The disk spring may compress flat when the further torque is applied. The use of a screw means that it is straightforward to use a long tool to operate the gripper when it is within the second element. In other embodiments the threaded element (of the fastener) may comprise a nut and the threaded feature (of the first gripper element) may comprise a threaded shaft. The features of the washer apply equally in any case.

The first element may be engaged with the foot, the foot extending in a first direction lateral to an axis of the first element, wherein the first gripper element is engaged with the first element such that an upper edge of the first inclined face points in the first direction. This will result in biasing of the upright member in a direction opposite to which the load will tend to deflect the upright member, thereby resulting in reduced deflection of the upright member under load.

The first gripper element may comprises a shoulder for resting on an end surface of the first element.

An end surface of the first element may comprise a notch, and the first gripper element may comprise a protrusion configured to be received by the notch when the first gripper element is mechanically engaged with the first element. The notch and protrusion may prevent relative rotation between the first gripper element and the first element. This enables torque to be applied to the fastener without affecting the clocking orientation of the first gripper element within the first element.

The stairlift system of any preceding claim, wherein the stanchion further comprises a graduated scale, configured to indicate the distance. The graduated scale may indicate the distance with reference to a variation from a predetermined distance (as an amount of adjustment, rather than as an absolute distance between the bottom surface of the foot and a mount). This may allow the stanchion to be pre-adjusted according to a predetermined plan more easily. The predetermined plan may be determined with reference to a survey of the intended installation site for the stairlift system.

The graduated scale may be fixed to the first element. The graduated scale comprises a removable sticker or transfer.

The stairlift system may further comprise a chair or platform, and means for moving the chair or platform along the rails. According to a second aspect, there is provided a gripper for fixing the length of a telescopic tube. The telescopic tube comprises a first tube and second tube. The first tube is at least partly disposed within and concentric to the second tube. The gripper is configured to reversibly frictionally engage with an interior surface of the first and/or second tube.

In some embodiments, the gripper may be configured to abut (mechanically engage with) the end of the first tube (e.g. with a shoulder feature), and to reversibly frictionally engage with an interior surface of the second tube . The gripper may include any of the features of the gripper disclosed with respect to the first aspect.

Embodiments will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded diagram of stanchion according to an embodiment; Figure 2 is a sectional drawing of an assembled stanchion of Figure 1 ; Figure 3 is a drawing of a stanchion mount and a stair rail section;

Figure 4 is a detail view of an scale for setting the height of a stanchion mount; Figure 5 is a detail view of an upper end of a lower stanchion element;

Figure 6 is an assembled view of a gripper according to an embodiment; and Figure 7 is an exploded diagram of the gripper of Figure 6. Referring to Figures 1 and 2, a stanchion 10 for supporting a stair rail of a stairlift system according to an embodiment is shown. The stanchion 10 comprises a foot 9 that supports an upstanding member which carries a pair of mounts 1 1 to which a stair rail (not shown) is attachable. Figure 3 illustrates a section of stair rail 20, for attachment to the mount 1 1. The mount 1 1 may comprise a threaded hole, and the rail 20 may be secured to the mount using a screw. The stair rail 20 may comprise a gear rack 21 , for moving a platform or chair of the stairlift.

The foot 9 of the stanchion 10 extends lateral to the upstanding member. The foot 9 serves to spread any vertical load from the upstanding member, and to increase the stability of the upstanding member. The foot 9 includes a plurality of holes 28 for receiving screws (not shown) for securing the foot 9 to a floor (not shown). The foot 9 comprises a bottom surface 26 for resting on the floor and a sleeve 30 for receiving the upstanding member. The upstanding member comprises a first (lower) element 8 and second (upper) element 7. A first end portion 27 of the lower element 8 is received by the foot 9 in the sleeve 30. The lower element 8 in this example is secured in the sleeve 30 by a roll pin 9, but any suitable method may be used, for example : bonding, an interference fit, using a rivet. The roll pin 9 aligns the first element 8 relative to the foot 9. The lower element 8 and upper element 7 are tubular. In this example circular tubes are used, but other shapes of tubes may be used. A cap 1 is provided for blocking the hole in the top of the upper element 7.

The upper element 7 comprises the mounts 1 1 , and is configured to slide concentrically over the lower element 8 so as to adjust a height of the mounts 1 1 above the floor or bottom surface 26 of the foot 9.

The position of the upper element 7 with respect to the lower element 8 can be locked in place using the gripper 40.

The gripper 40 is more clearly shown in Figures 6 and 7, and comprises a first (lower) gripper element 6 and a second (upper) gripper element 5, fastener 2, disk spring 3 and flat washer 2. The gripper 40 mechanically engages with the lower element 8, and the fastener 2 is used to cause a reversible frictional engagement of the gripper 40 with the upper element 7. When the gripper 40 is mechanically engaged with the lower element 8 and frictionally engaged with the upper element 7, the height of the mounts 1 1 above the floor is fixed because the upper element 7 is prevented from moving downwards relative to the lower element 8. When the gripper is not frictionally engaged with the upper element 7, the height of the mounts 1 1 above the floor may be adjusted by relative movement of the upper and lower elements 8, 7.

The lower gripper element 6 mechanically engages with the lower element 8 of the upright member. The lower element 8 is provided with a shoulder 3 1 that is configured to contact an upper surface 13 of an end of the lower element 8, so as to transfer vertical loads from the lower gripper element 6 to the lower element 8 of the upright member. A protrusion 18 is provided adjacent to the shoulder 3 1 , that is configured to be received within a corresponding notch 14 in the upper surface 13 of the lower element 8, so as to prevent mutual rotation of the lower gripper element 6 and the lower element 8 of the upright member. The orientation of the notch 14 with respect to the foot 9 may be defined by the roll pin 9 that fixes the orientation of the first element 8 relative to the foot 9. The lower gripper element 6 is also configured for frictional engagement with an interior of the lower element 8, so as to resist being pulled out of the lower element 8. A plurality of radial ribs 32 are provided for this purpose, configured to be received within an interior of the lower element 8. The ribs 32 are each provided with a tapering ridge 19, for providing a tapering interference fit with the interior surface of the lower element 8. Although the example embodiment comprises four ribs, alternative embodiments may use fewer, or more ribs (for example, 2, 3, 5 or 6 ribs). The lower gripper element 6 further comprises a first inclined surface 15 and threaded hole 25. The threaded hole 25 defines an axis of the lower gripper element 6 (or gripper axis). The lower gripper element 6 is configured such that the gripper axis is substantially parallel with an axis of the lower element 8 when the lower gripper element 6 is engaged with the lower element 8.

The upper gripper element 5 comprises a second inclined surface 16, a clearance hole 24 and a friction surface 27. The first and second inclined surfaces 15, 16 (of the lower and upper gripper elements 6, 5 respectively) are configured for sliding engagement with each other.

The fastener 2 comprises a shaft 23 having a threaded portion for screwing into the tapped hole 24 of the lower gripper element 6, and a head for rotating the fastener 2 and screwing it into the tapped hole 24. The clearance hole 24 of the upper gripper element 5 is configured to receive the fastener shaft 23, so that the upper gripper element 5 is secured to the lower gripper element 6 when the fastener 2 is screwed into the lower gripper element 6. The head of the fastener 2 is configured to engage with a surface of the upper gripper element 5. As the fastener 2 is screwed into the threaded hole 25 of the lower element 6, the distance between the fastener head and the first inclined surface 15 is decreased. In some embodiments, a washer 3, 4 may be provided for positioning between the surface of the upper gripper element 5 and the fastener head, so as to distribute the load from the fastener head and prevent wear or damage to the surface of the upper gripper element 5 when the fastener 2 is tightened.

In some embodiments a disk spring 3 may be provided for positioning immediately adjacent to the fastener head, and a further plain washer 4 may be provided for positioning between the plain washer 3 and the upper gripper element 5. In some embodiments a disk spring 3 is provided between the upper gripper element 5 and the fastener head to apply a controlled preload to allow sliding adjustment between the upper element 7 and the gripper element frictional face 27. The disk spring 3 may allow a controlled frictional engagement pre-load that is sufficient to support the weight of the second element 7, but which also allows sliding adjustment by a user of the height of the mounts 1 1. Once the a desired height is selected the further clamping force may be applied by the fastener so as to cause sufficient frictional engagement to support the load from the rail 20, which may render the disk spring 3 flat.

As the fastener 2 is screwed into the threaded hole 25, the first and second inclined faces 16, 15 of the upper and lower gripper elements 5, 6 are brought into engagement. Following engagement, any further reduction of the distance between the fastener head and the first inclined surface 16 must be accommodated by sliding contact between the first and second inclined surfaces 16, 15, resulting in movement of the upper gripper element 5 relative the lower gripping element 6 in a direction parallel to the first inclined surface. This results in a lateral movement (relative to the gripper axis) of the friction face 27 of the upper gripper element 5. The gripper is configured such that this lateral movement of the friction face 27 may bring it into frictional engagement with an inner surface of the upper member 7. This frictional engagement locks the upper element 7 of the upright member from moving downwards relative to the lower element 8 of the upright member and fixes the height of the mounts 1 1 above the floor.

Since there is a clearance fit between the lower and upper elements 8, 7 of the upright member, a small amount of relative rotation (depending on the manufacturing tolerance of the clearance fit) may be accommodated between the lower and upper elements 8, 7 when a bending moment is exerted on the upright member (via the mounts 1 1). The gripper 40 may be arranged to bias the rotation of the upper element away from the direction in which the foot extends, so that the upright member is pre- biased away from a direction of deflection in response to loading via the mounts 1 1 by the chair or platform. In the example embodiment, this is achieved by arranging the gripper 40 such that the frictional face engages with an interior face of the upper element 7 that is on the opposite side to the mounts 1 1. This pre-biases the stanchion with a slight bend away from the direction of loading, so that the flexing of the stanchion towards the load is minimised. This may help the user to feel secure by minimising any undesirable tipping of the platform or chair. The gripper 40 of the example embodiment is configured to be locked and unlocked with a single fastener 2. The gripper 40 and the locking fastener 2 is hidden from the view of the user following installation, because it is within the upright member and the cap blocks viewing the gripper 40 along the axis of the upper element 7. The height of the mounts 1 1 above the floor may therefore be adjusted in a simple way, which may save time and effort in installing a stair rail system comprising such a stanchion 10. Furthermore, because adjustment of the height of the mounts 1 1 is more straightforward, a satisfactory installation of a stair rail system is more likely. In some embodiments, a graduated scale 12 may be provided to indicate a distance between the bottom 26 of the foot 9 and one or more of the mounts 1 1. An example of such a scale 12 is shown in Figure 4. The scale 12 may be etched, stamped or printed on the lower element 8, or may alternatively be a sticker or transfer that is applied to the lower element. The scale allows a user to set the height of each stanchion 10 to a predetermined height. For example, the installation location may first be surveyed, and the appropriate heights for each stanchion mount determined. The determination of appropriate stanchion heights may be performed automatically from data using a computer. Using the scale, each stanchion may readily me set to a precise height with the minimum of effort, making installation straightforward.

Although an embodiment has been described in which the lower element is received within the upper element, an alternative embodiment is envisaged in which the upper element is received within the lower element. In other embodiments the fastener may be a nut, and the lower gripper element may comprise a threaded shaft.

Although references have been made to "upper" and "lower" features of the stanchion and to an "upright member", it will be appreciated that these terms are merely convenient ways to describe the stanchion in a particular orientation and these are not intended to limit the scope of the disclosure . The terms "lower" and "upper" in the specification may be substituted with "first" and "second" . In some embodiments the second gripper element may be configured to engage with the first element of the upright member and the first gripper element may be configured to engage with the second element of the upright member. A number of other variations will be apparent to the skilled person. The scope of the invention is defined only by the appended claims.