FIELD OF THE INVENTION

The invention relates to the field of stair lifts for moving a person along a staircase.

BACKGROUND OF THE INVENTION

Stair lifts are installed in many residential buildings across the globe, as well as other types of buildings. A stair lift greatly increases accessibility for people who have difficulties navigating staircases due to physical or mental limitations, such as elderly or disabled persons.

However, not all staircases are suitable for installing a stair lift, since most staircases are not designed with compatibility with a stair lift in mind. A problem that may occur in this context is the attribute of most stair lifts that the rail of the stair lift protrudes beyond the staircase at the top. This makes it hard or impossible to install a stair lift on staircases where an obstruction is present at or near the top of the staircase, such as a door.

OBJECTIVE OF THE INVENTION

It is an object of the invention to provide a stair lift capable of being installed on a staircase where an obstruction is present at or near the top of the staircase.

It is a further object of the invention to provide an adaptor system for installing a stair lift on a staircase where an obstruction is present at or near the top of the staircase.

It is a further object of the invention to provide a method of installing a stair lift on a staircase where an obstruction is present at or near the top of the staircase.

SUMMARY OF THE INVENTION

In a first aspect of the invention, the invention comprises a stair lift set comprising a stair lift for moving a person along a staircase and an adaptor system, wherein - the stair lift comprises a straight rail which in use extends along the staircase, rail supports for holding the rail in position, a carriage which is movable along the rail, a seat for supporting a user, and a seat support for mounting the seat to the carriage,

- the seat support is configured to hold the seat in use in a seat position relative to the carriage,

- the rail supports comprise a rail support mounting part suitable for mounting the rail support to the staircase,

- the rail supports are configured to hold the rail in use at horizontal rail distance from the rail support mounting part when seen from a viewing direction perpendicular to a virtual vertical plane extending through a longitudinal rail axis of the rail,

- the adaptor system comprises multiple rail adaptors and a seat adaptor,

- each rail adaptor comprises a rail adaptor mounting part for mounting the rail adaptor to the staircase and a rail adaptor supporting part configured to be mounted to the rail support mounting part of the rail support to hold the rail in use at a horizontal adapted rail distance from the rail adaptor mounting part when seen from said viewing direction,

- the horizontal adapted rail distance is larger than the horizontal rail distance,

- the seat adaptor is configured to be mounted between the seat and the carriage in order to hold the seat in use in an adapted seat position relative to the carriage,

- the adapted seat position is located at a horizontal seat distance from the seat position relative to the carriage when seen from said viewing direction, and

- the horizontal seat distance compensates at least part of a horizontal rail distance difference between the horizontal adapted rail distance and the horizontal rail distance.

This stair lift set is installable on staircases with an obstruction at or near the top of the staircase, without removal or displacement of the obstruction. This is advantageous for example in residential buildings where modifying the building in order to fit the stair lift is undesirable. The rail adaptors allow the rail to be shifted in the horizontal direction when compared to a stair lift without the adaptor system, limiting or even eliminating a protrusion of the rail beyond the top riser of the staircase, such that the rail does not interfere with an obstruction at or near the top of the staircase.

The seat adapter horizontally shifts the seat with respect to the carriage in order to at least partially compensate for the horizontal shifting of the rail effected by the rail adaptors, in order to decrease the distance between the seat and the landing at the top of the staircase if the seat is in its topmost position. This allows safe, easy boarding and deboarding of the seat at the top of the staircase. The horizontal seat distance may be measured between an adapted vertical seat centre line of the seat in the adapted seat position and a vertical seat centre line of the seat in the seat position for a given position of the carriage and parallel to said virtual vertical plane when seen from said viewing direction. The vertical seat centre line and the adapted vertical seat centre line extend vertically through a seat centre of the seat in the seat position and the adapted seat position, respectively.

The horizontal rail distance may be measured between a vertical rail support mounting centre line of the rail support mounting part that extends through the rail support mounting centre of the rail support mounting part and a longitudinal rail axis of the rail in horizontal direction at a rail support height of said rail support mounting part and parallel to said virtual vertical plane when seen from said viewing direction. This relates to the situation in which no rail adaptors are mounted to the rail support mounting parts of the rail supports.

The rail support height may be defined as the vertical position of the lower contact surface of the rail support mounting part when seen from said viewing direction.

The horizontal adapted rail distance may be measured between a vertical rail adaptor mounting centre line of the rail adaptor mounting part that extends through a rail adaptor mounting centre of the rail adaptor mounting part and the longitudinal rail axis in horizontal direction at the rail support height of said rail support mounting part and parallel to said virtual vertical plane when seen from said viewing direction. The vertical rail adaptor mounting centre line extends vertically through a rail adaptor mounting centre of the rail adaptor mounting part. This relates to the situation in which rail adaptors are mounted to the rail support mounting parts of the rail supports.

The horizontal rail distance difference is obtained by subtracting said horizontal rail distance from said horizontal adapted rail distance.

In an embodiment of the stair lift set, the horizontal seat distance compensates between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance compensates between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance compensates between 90% - 110% of the horizontal rail distance difference, or the horizontal seat distance compensates the horizontal rail distance difference completely.

In an embodiment of the stair lift set, the horizontal seat distance is between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance is between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance is between 90% - 110% of the horizontal rail distance difference, or the horizontal seat distance is equal to the horizontal rail distance difference.

In an embodiment of the stair lift set, a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction is opposite to a second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction.

In an embodiment of the stair lift set, the seat adaptor is configured to reposition the seat in a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction and the rail adaptors are configured to reposition the rail in an opposite second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction.

In an embodiment of the stair lift set, when seen from said viewing direction, the rail adaptors are configured to provide a horizontal rail offset of the rail of the stair lift installed on the staircase with the rail adaptors when compared with the rail of the stair lift installed on the staircase without the rail adaptors, when seen from said viewing direction, the seat adaptor is configured to provide a horizontal seat offset of the seat of the stair lift having the seat adaptor mounted between the seat and carriage when compared with the seat of the stair lift having no seat adaptor mounted between the seat and the carriage, the horizontal seat offset is equal to the horizontal seat distance, and the horizontal seat offset compensates at least part of the horizontal rail offset.

In an embodiment of the stair lift set, the horizontal seat offset compensates between 50% - 150% of the horizontal rail offset, or the horizontal seat offset compensates between 75% -

125% of the horizontal rail offset, or the horizontal seat offset compensates between 90% -

110% of the horizontal rail offset, or the horizontal seat offset compensates the horizontal rail offset completely.

In an embodiment of the stair lift set, the horizontal rail offset is determined by comparing the stair lift being installed on the staircase without the rail adaptors and having the rail support mounting parts mounted to the staircase at rail support mounting positions with the stair lift being installed on the staircase with the rail adaptors and having the rail adaptor mounting parts mounted to the staircase at the rail support mounting positions. In an embodiment of the stair lift set, the rail adaptors are configured to be supported on their rail adaptor mounting part by a respective rail mounting step of the staircase such that the rail adaptor supporting part is positioned at a horizontal adaptor distance from a rail mounting step tread of the respective rail mounting step of the staircase, or such that the rail adaptor supporting part extends beyond a rail mounting step tread of the respective rail mounting step of the staircase. This allows the rail adaptors to support the rail supports at a position that lies at least partially horizontally beyond the tread of the rail mounting steps on which the rail adaptors are supported.

The horizontal adaptor distance may be measured along a horizontal line between a mounting step tread end and a vertical adaptor support centre line that extends vertically through the rail adaptor support centre of the rail adaptor supporting part.

In an embodiment of the stair lift set, the rail adaptors are configured to be supported on their rail adaptor mounting part by the respective rail mounting step tread.

In an embodiment of the stair lift set, the rail support mounting parts are configured to mount the rail support to the staircase at a rail support mounting position on the respective rail mounting step treads of respective rail mounting steps of the staircase, and the rail adaptor mounting parts are configured to mount the rail adaptors to the staircase at the rail support mounting position on said respective rail mounting step treads of respective rail mounting steps of the staircase. In this embodiment, the rail adaptors are configured to be mounted to the staircase in the same position as the rail supports would be mounted if the stair lift were installed without the adaptor system.

In an embodiment of the stair lift set, the rail adaptors comprise a support member for supporting the rail adaptor supporting part. This enhances the support of the stair lift.

In an embodiment of the stair lift set, the support member comprises a support leg which is configured to be supported on a support step below the rail mounting step.

In an embodiment of the stair lift set, the support step is a subsequent step directly below the rail mounting step.

In an embodiment of the stair lift set wherein the rail adaptors comprise a support member for supporting the rail adaptor supporting part, the support member is an angled support member configured to be connected to a riser of at least one step. In an embodiment of the stair lift set, the support member is an angled support member configured to be connected to a rail mounting step riser of the rail mounting step.

In an embodiment of the stair lift set, the seat adaptor comprises a first seat adaptor connecting part and a second seat adaptor connecting part, and the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the carriage, or the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the seat support, or the first seat adaptor connecting part is configured to be mounted to the seat support and the second seat adaptor connecting part is configured to be mounted to the carriage.

It will be clear to the skilled person that the features of any of the above mentioned embodiments of the stair lift may be combined.

In a second aspect of the invention, the invention comprises an adaptor system for use on a stair lift for moving a person along a staircase, wherein the stair lift comprises a straight rail which in use extends along the staircase, rail supports for holding the rail in position, a carriage which is movable along the rail, a seat for supporting a user, and a seat support for mounting the seat to the carriage, the seat support is configured to hold the seat in use in a seat position relative to the carriage, the rail supports comprise a rail support mounting part suitable for mounting the rail support to the staircase, the rail supports are configured to hold the rail in use at horizontal rail distance from the rail support mounting part when seen from a viewing direction perpendicular to a virtual vertical plane extending through a longitudinal rail axis of the rail, wherein

- the adaptor system comprises multiple rail adaptors and a seat adaptor,

- each rail adaptor comprises a rail adaptor mounting part for mounting the rail adaptor to the staircase and a rail adaptor supporting part configured to be mounted to the rail support mounting part of the rail support to hold the rail in use at a horizontal adapted rail distance from the rail adaptor mounting part when seen from said viewing direction,

- the horizontal adapted rail distance is larger than the horizontal rail distance,

- the seat adaptor is configured to be mounted between the seat and the carriage in order to hold the seat in use in an adapted seat position relative to the carriage,

- the adapted seat position is located at a horizontal seat distance from the seat position when seen from said viewing direction, and - the horizontal seat distance compensates at least part of a horizontal rail distance difference between the horizontal adapted rail distance and the horizontal rail distance.

This adaptor system allows a stair lift to be installed on staircases with an obstruction at or near the top of the staircase, without removal or displacement of the obstruction. This is advantageous for example in residential buildings where modifying the building in order to fit the stair lift is undesirable. The rail adaptors allow the rail to be shifted in the horizontal direction when compared to a stair lift without the adaptor system, limiting or even eliminating a protrusion of the rail beyond the top riser of the staircase. The seat adaptor ensures that the seat is in a position that allows safe, easy boarding and deboarding of the seat at both the top and bottom of the staircase.

A further advantage of providing such an adaptor system is that a standard stair lift can be installed on staircases with an obstruction at or near the top of the staircase. Not needing to adapt the stair lift as a result of the obstruction reduces cost and complexity. Certification of the stair lift is simplified as well, seeing that only a single type of stair lift needs to be certified. The adaptor system can then be certified in combination with the already certified stair lift, in order to allow installation of the stair lift set in many different situations.

In an embodiment of the adaptor system, the horizontal seat distance compensates between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance compensates between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance compensates between 90% - 110% of the horizontal rail distance difference, or the horizontal seat distance compensates the horizontal rail distance difference completely.

In an embodiment of the adaptor system, the horizontal seat distance is between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance is between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance is between 90%

- 110% of the horizontal rail distance difference, or the horizontal seat distance is equal to the horizontal rail distance difference.

In an embodiment of the adaptor system, a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction is opposite to a second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction. In an embodiment of the adaptor system, the seat adaptor is configured to reposition the seat in a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction and the rail adaptors are configured to reposition the rail in an opposite second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction.

In an embodiment of the adaptor system, when seen from said viewing direction, the rail adaptors are configured to provide a horizontal rail offset of the rail of the stair lift installed on the staircase with the rail adaptors when compared with the rail of the stair lift installed on the staircase without the rail adaptors, when seen from said viewing direction, the seat adaptor is configured to provide a horizontal seat offset of the seat of the stair lift having the seat adaptor mounted between the seat and carriage when compared with the seat of the stair lift having no seat adaptor mounted between the seat and the carriage, the horizontal seat offset is equal to the horizontal seat distance, and the horizontal seat offset compensates at least part of the horizontal rail offset.

In an embodiment of the adaptor system, the horizontal seat offset compensates between

50% - 150% of the horizontal rail offset, or the horizontal seat offset compensates between

75% - 125% of the horizontal rail offset, or the horizontal seat offset compensates between

90% - 110% of the horizontal rail offset, or the horizontal seat offset compensates the horizontal rail offset completely.

In an embodiment of the adaptor system, the horizontal rail offset is determined by comparing the stair lift being installed on the staircase without the rail adaptors and having the rail support mounting parts mounted to the staircase at rail support mounting positions with the stair lift being installed on the staircase with the rail adaptors and having the rail adaptor mounting parts mounted to the staircase at the rail support mounting positions.

In an embodiment of the adaptor system, the rail adaptors are configured to be supported on their rail adaptor mounting part by a respective rail mounting step of the staircase such that the rail adaptor supporting part is positioned at a horizontal adaptor distance from a rail mounting step tread of the respective rail mounting step of the staircase, or such that the rail adaptor supporting part extends beyond a rail mounting step tread of the respective rail mounting step of the staircase. This allows the rail adaptors to support rail supports of a stair lift at a position that lies at least partially beyond the tread of the rail mounting steps on which the rail adaptors are supported. In an embodiment of the adaptor system, the rail adaptors are configured to be supported on their rail adaptor mounting part by the respective rail mounting step tread.

In an embodiment of the adaptor system, the rail support mounting parts are configured to mount the rail support to the staircase at a rail support mounting position on the respective rail mounting step treads of respective rail mounting steps of the staircase, and the rail adaptor mounting parts are configured to mount the rail adaptors to the staircase at the rail support mounting position on said respective rail mounting step treads of respective rail mounting steps of the staircase.

In an embodiment of the adaptor system, the rail adaptors comprise a support member for supporting the rail adaptor supporting part.

In an embodiment of the adaptor system, the support member comprises a support leg which is configured to be supported on a support step below the rail mounting step.

In an embodiment of the adaptor system, the support step is a subsequent step directly below the rail mounting step.

In an embodiment of the adaptor system wherein the rail adaptors comprise a support member for supporting the rail adaptor supporting part, the support member is an angled support member configured to be connected to a riser of at least one step.

In an embodiment of the adaptor system, the support member is an angled support member configured to be connected to a rail mounting step riser of the rail mounting step.

In an embodiment of the adaptor system, the seat adaptor comprises a first seat adaptor connecting part and a second seat adaptor connecting part, and the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the carriage, or the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the seat support, or the first seat adaptor connecting part is configured to be mounted to the seat support and the second seat adaptor connecting part is configured to be mounted to the carriage.

It will be clear to the skilled person that the features of any of the above mentioned embodiments of the adaptor system may be combined. In a third aspect of the invention, the invention comprises a method of installing a stair lift set on a staircase, wherein the stair lift set comprises a stair lift for moving a person along a staircase and an adaptor system, wherein the stair lift comprises a straight rail which in use extends along the staircase, rail supports for holding the rail in position, a carriage which is movable along the rail, a seat for supporting a user, and a seat support for mounting the seat to the carriage, the seat support is configured to hold the seat in use in a seat position relative to the carriage, the rail supports comprise a rail support mounting part suitable for mounting the rail support to the staircase, the rail supports are configured to hold the rail in use at horizontal rail distance from the rail support mounting part when seen from a viewing direction perpendicular to a virtual vertical plane extending through a longitudinal rail axis of the rail, wherein the adaptor system comprises multiple rail adaptors and a seat adaptor, each rail adaptor comprises a rail adaptor mounting part for mounting the rail adaptor to the staircase and a rail adaptor supporting part configured to be mounted to the rail support mounting part of the rail support to hold the rail in use at a horizontal adapted rail distance from the rail adaptor mounting part when seen from said viewing direction, the horizontal adapted rail distance is larger than the horizontal rail distance, the seat adaptor is configured to be mounted between the seat and the carriage in order to hold the seat in use in an adapted seat position relative to the carriage, the adapted seat position is located at a horizontal seat distance from the seat position when seen from said viewing direction, and the horizontal seat distance compensates at least part of a horizontal rail distance difference between the horizontal adapted rail distance and the horizontal rail distance, wherein the method comprises the steps of

- connecting the rail supports to the rail,

- connecting the rail adaptor mounting parts of the rail adaptors to the staircase,

- positioning the rail at the horizontal adapted rail distance from the rail adaptor mounting part by connecting the rail adaptor supporting parts of the rail adaptors to the rail support mounting parts of the rail supports,

- positioning the seat in the adapted seat position relative to the carriage by mounting the seat adaptor in between the carriage and the seat.

This method allows installing a stair lift on staircases with an obstruction at or near the top of the staircase, without removal or displacement of the obstruction. This is advantageous for example in residential buildings where modifying the building in order to fit the stair lift is undesirable. The rail adaptors allow the rail to be shifted in the horizontal direction when compared to a stair lift without the adaptor system, limiting or even eliminating a protrusion of the rail beyond the top riser of the staircase. The seat adaptor ensures that the seat is in a position that allows safe, easy boarding and deboarding of the seat at both the top and bottom of the staircase.

Because a conventional stair lift is used, the installation process is relatively familiar to a person skilled in installing stair lifts. This enables easy, fast and reliable installation of the stair lift.

In an embodiment of the method, the horizontal seat distance compensates between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance compensates between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance compensates between 90% - 110% of the horizontal rail distance difference, or the horizontal seat distance compensates the horizontal rail distance difference completely.

In an embodiment of the method, the horizontal seat distance is between 50% - 150% of the horizontal rail distance difference, or the horizontal seat distance is between 75% - 125% of the horizontal rail distance difference, or the horizontal seat distance is between 90% - 110% of the horizontal rail distance difference, or the horizontal seat distance is equal to the horizontal rail distance difference.

In an embodiment of the method, a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction is opposite to a second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction.

In an embodiment of the method, the seat adaptor is configured to reposition the seat in a first horizontal direction from the seat position to the adapted seat position when seen from said viewing direction and the rail adaptors are configured to reposition the rail in an opposite second horizontal direction from the rail adaptor mounting part to the rail support mounting part when seen from said viewing direction.

In an embodiment of the method, when seen from said viewing direction, the rail adaptors are configured to provide a horizontal rail offset of the rail of the stair lift installed on the staircase with the rail adaptors when compared with the rail of the stair lift installed on the staircase without the rail adaptors, when seen from said viewing direction, the seat adaptor is configured to provide a horizontal seat offset of the seat of the stair lift having the seat adaptor mounted between the seat and carriage when compared with the seat of the stair lift having no seat adaptor mounted between the seat and the carriage, the horizontal seat offset is equal to the horizontal seat distance, and the horizontal seat offset compensates at least part of the horizontal rail offset.

In an embodiment of the method, the horizontal seat offset compensates between 50% - 150% of the horizontal rail offset, or the horizontal seat offset compensates between 75% -

125% of the horizontal rail offset, or the horizontal seat offset compensates between 90% -

110% of the horizontal rail offset, or the horizontal seat offset compensates the horizontal rail offset completely.

In an embodiment of the method, the horizontal rail offset is determined by comparing the stair lift being installed on the staircase without the rail adaptors and having the rail support mounting parts mounted to the staircase at rail support mounting positions with the stair lift being installed on the staircase with the rail adaptors and having the rail adaptor mounting parts mounted to the staircase at the rail support mounting positions.

In an embodiment of the method, the method comprises the step of supporting the rail adaptors on their rail adaptor mounting part on a respective rail mounting step of the staircase, and the method further comprises the step of positioning the rail adaptor supporting part at a horizontal adaptor distance from a rail mounting step tread of the respective rail mounting step of the staircase, or positioning the rail adaptor supporting part such that it extends beyond a rail mounting step tread of the respective rail mounting step of the staircase. This allows supporting the rail supports on the rail adaptors at a position that lies at least partially beyond the tread of the rail mounting steps on which the rail adaptors are supported.

In an embodiment of the method, the method comprises the step of supporting the rail adaptors on their rail adaptor mounting part on the respective rail mounting step tread.

In an embodiment of the method, wherein the rail support mounting parts are configured to mount the rail support to the staircase at a rail support mounting position on the respective rail mounting step treads of respective rail mounting steps of the staircase, the method comprises the step of mounting the rail adaptor mounting parts to the staircase at the rail support mounting position on said respective rail mounting step treads of respective rail mounting steps of the staircase.

In an embodiment of the method, the method comprises the step of connecting the rail adaptor supporting part to a support member. In an embodiment of the method, wherein the support member comprises a support leg, the method comprises the steps of providing the support leg with a length that substantially corresponds with a height difference between the rail mounting step tread and a support step tread of a support step below the rail mounting step of the staircase and supporting the rail adaptor supporting part by placing the support leg on the support step tread.

In an embodiment of the method, the support step is a subsequent step directly below the first step.

In an embodiment of the method, wherein the method comprises the step of connecting the rail adaptor supporting part to a support member, wherein the support member is an angled support member, the method comprises the step of connecting the angled support member to a riser of at least one step of the staircase.

In an embodiment of the method, the method comprises the step of connecting the angled support member to a rail mounting step riser of the rail mounting step.

In an embodiment of the method, wherein the seat adaptor is configured to replace the seat support, and wherein the seat adaptor comprises a first seat adaptor connecting part and a second seat adaptor connecting part, wherein the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the carriage, the method comprises the step of replacing the seat support by the seat adaptor by connecting the first seat adaptor connecting part of the seat adaptor to the seat, and connecting the second seat adaptor connecting part of the seat adaptor to the carriage.

In an embodiment of the method, wherein the seat adaptor is configured to be mounted to the carriage and the seat support, and wherein the seat adaptor comprises a first seat adaptor connecting part and a second seat adaptor connecting part, wherein the first seat adaptor connecting part is configured to be mounted to the seat support and the second seat adaptor connecting part is configured to be mounted to the carriage, the method comprises the step of mounting the seat adaptor between the carriage and the seat support by the seat adaptor by connecting the second seat adaptor connecting part of the seat adaptor to the carriage, and connecting the first seat adaptor connecting part of the seat adaptor to the seat support.

In an embodiment of the method, wherein the seat adaptor is configured to be mounted to the seat and the seat support, and wherein the seat adaptor comprises a first seat adaptor connecting part and a second seat adaptor connecting part, wherein the first seat adaptor connecting part is configured to be mounted to the seat and the second seat adaptor connecting part is configured to be mounted to the seat support, the method comprises the step of mounting the seat adaptor between the seat and the seat support by connecting the first seat adaptor connecting part of the seat adaptor to the seat, and connecting the second seat adaptor connecting part of the seat adaptor to the seat support.

It will be clear to the skilled person that the features of any of the above mentioned embodiments of the method may be combined.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the stair lift set according to the invention, the adaptor system according to invention and the method according to the invention will be described by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

Figure 1 schematically shows a side view of a stair lift installed on a staircase,

Figures 2A - 2C schematically shows a side view of a first, second and third embodiment of the stair lift set according to the invention,

Figure 3 schematically shows a top view of the stair lift set of figure 2A,

Figures 4 and 5 schematically show a side view of a fourth and fifth embodiment of the stair lift set according to the invention, including different types of support members,

Figure 6 schematically shows a side view of a sixth embodiment of the stair lift set according to the invention, wherein the rail is offset to a larger extent than would be necessary in order to nullify the horizontal protrusion of the rail beyond the top riser of the staircase,

Figure 7 schematically shows a side view of a seventh embodiment of the stair lift set according to the invention, wherein the rail slightly protrudes in a horizontal direction beyond the top riser of the staircase,

Figure 8 schematically shows a top view of one of the rail adaptors of the stair lift set of Fig. 2A, and

Figures 9A - 9C schematically shows side views of the seat adaptors of the stair lift sets of Figs. 2A - 2C, respectively. DETAILED DESCRIPTION OF DRAWINGS

Fig. 1 shows a side view of a stair lift 2 installed on a staircase 3 as seen from a viewing direction 46 perpendicular to a virtual vertical plane 45 extending through a longitudinal rail axis 39 of a straight rail 5 of the stair lift 2. The stair lift 2 comprises rail supports 6 for holding the rail 5 in position, a carriage 7 which is movable along the rail 5, and a seat 8 for supporting a user. The seat 8 is connected to the carriage 7 by a seat support 10 which holds the seat 8 in use at a seat position 37 relative to the carriage. The rail supports 6 comprise a rail support mounting part 12 for mounting the rail support 6 to the staircase 3. The rail supports 6 hold the rail 5 at a horizontal rail distance 13 from the rail support mounting part 12. The horizontal rail distance 13 is measured between a vertical rail support mounting centre line 41 of the rail support mounting part 12 that extends through the rail support mounting centre 64 of the rail support mounting part 12 and the longitudinal rail axis 39 of the rail 5 in horizontal direction at a rail support height 42 of said rail support mounting part 12 and parallel to said virtual vertical plane 45 when seen from said viewing direction 46. The rail support height 42 is the vertical position of a lower contact surface 55 of the rail support mounting part 12 when seen from said viewing direction 46.

In Fig. 1, the rail 5 comprises a rail protrusion 47 that protrudes over a rail protrusion distance 48 beyond the top riser 49 of the staircase 3. This rail protrusion 47 is required, because the seat 8 would otherwise not be able to go high enough along the rail 5 to allow safe boarding and deboarding of the seat 8 at the top of the staircase 3. This rail protrusion 47 makes it hard or impossible to install the stair lift 2 of Fig. 1 on a staircase 3 where an obstruction such as a door is present at or near the top of the staircase 3.

Figs. 2A, 2B, and 2C respectively show first, second, and third embodiment of a stair lift set 1 according to the invention installed on the staircase 3 of figure 1 , as seen from the viewing direction 46 perpendicular to the virtual vertical plane 45 extending through the longitudinal rail axis 39 of the rail 5. The stair lift set 1 of Fig. 2A is also shown in Fig. 3 in a top view, seen from a top view direction 50. Fig. 2A shows what a person would observe when looking in the viewing direction 46. Fig. 3 shows what a person would observe when looking in the top view direction 50.

The stair lift set 1 comprises the stair lift 2 of figure 1 and an adaptor system 4. The adaptor system comprises multiple rail adaptors 14 and a seat adaptor 15A, 15B, 15C. The seat adaptor 15A, 15B, 15C is mounted between the seat 8 and the carriage 7 and holds the seat 5 at an adapted seat position 38. The seat adaptor 15A may replace the seat support 10 (Fig. 2A), the seat adaptor 15B may be mounted to the seat 8 and the seat support 10 (Fig. 2B), or the seat adaptor 15C may be mounted to the carriage 7 and the seat support 10 (Fig. 2C). Figs. 9A, 9B, and 9C schematically show the seat adaptors 15A, 15B, 15C of Figs. 2A, 2B, and 2C, respectively.

When seen from said viewing direction 46, the rail adaptors 14 provide a horizontal rail offset 67 of the rail 5 of the stair lift 2 installed on the staircase 3 with the rail adaptors 14 when compared with the rail 5 of the stair lift 2 installed on the staircase 3 without the rail adaptors 14 (see Fig. 1). When seen from said viewing direction 46, the seat adaptor 15A, 15B, 15C provides a horizontal seat offset 68 of the seat 8 of the stair lift 2 having the seat adaptor 15A, 15B, 15C mounted between the seat 8 and carriage 7 when compared with the seat 8 of the stair lift 2 having no seat adaptor mounted 15A, 15B, 15C between the seat 8 and the carriage 7. The horizontal seat offset 68 is equal to the horizontal seat distance 11.

The stair lift 2 may be installed on the staircase 3 using the adaptor system 4 by connecting the rail supports 6 to the rail 5, connecting the rail adaptor mounting parts 16 of the rail adaptors 14 to the staircase 3, positioning the rail 5 at the horizontal adapted rail distance 18 from the rail adaptor mounting part 16 by connecting the rail adaptor supporting parts 17 of the rail adaptors 14 to the rail support mounting parts 12 of the rail supports 6, and positioning the seat 8 in the adapted seat position 38 relative to the carriage 7 by mounting the seat adaptor 15A, 15B, 15C in between the carriage 7 and the seat 8.

In the situation of the Figs. 2A - 2C, the horizontal seat offset 68 compensates the horizontal rail offset 67 completely. In other embodiments of the stair lift set, the horizontal seat offset 68 may compensate between 50% - 150% of the horizontal rail offset 67, or the horizontal seat offset 68 may compensate between 75% - 125% of the horizontal rail offset 67, or the horizontal seat offset 68 may compensate between 90% - 110% of the horizontal rail offset 67.

The horizontal rail offset 67 is determined by comparing the stair lift 2 being installed on the staircase 3 without the rail adaptors 14 and having the rail support mounting parts 12 mounted to the staircase 3 at rail support mounting positions 69 with the stair lift 2 being installed on the staircase 3 with the rail adaptors 14 and having the rail adaptor mounting parts 16 mounted to the staircase 3 at the rail support mounting positions 69.

In Fig. 2A, a first seat adaptor connecting part 35 of the seat adaptor 15A is mounted to the seat 8 and a second seat adaptor connecting part 36 of the seat adaptor 15A is mounted to the carriage. See also Fig. 9A. In Fig. 2B, a first seat adaptor connecting part 35 of the seat adaptor 15B is mounted to the seat 8 and the second seat adaptor connecting part 36 of the seat adaptor 15B is mounted to the seat support 10. See also Fig. 9B. In Fig. 2C, a first seat adaptor connecting part 35 of the seat adaptor 15C is configured to be mounted to the seat support 10 and the second seat adaptor connecting part 36 of the seat adaptor 15C is configured to be mounted to the carriage 7. See also Fig. 9C.

The adapted seat position 38 is located at a horizontal seat distance 11 from the seat position 37 when seen from the viewing direction 46, wherein the horizontal seat distance 11 is measured between an adapted vertical seat centre line 40B of the seat 8 in the adapted seat position 38 and a vertical seat centre line 40A of the seat 8 in the seat position 37 for a given position of the carriage 7 and parallel to said virtual vertical plane 45 when seen from said viewing direction 46. The vertical seat centre line 40A and the adapted vertical seat centre line 40B extend vertically through a seat centre 63 of the seat in the seat position 37 and the adapted seat position 38, respectively.

A first horizontal direction 65 from the seat position 37 to the adapted seat position 38 is opposite to a second horizontal direction 66 from the rail adaptor mounting part 16 to the rail support mounting part 12. The seat adaptor 15A, 15B, 15C repositions the seat 8 in the first horizontal direction 65, whereas the rail adaptors 14 reposition the rail 5 in the second horizontal direction 66.

Each rail adaptor 14 comprises a rail adaptor mounting part 16 by which the rail adaptor 14 is mounted to the staircase 3, as well as a rail adaptor supporting part 17 which is mounted to the rail support mounting part 12 of a rail support 6. The rail adaptors 14 thereby hold the rail 5 at a horizontal adapted rail distance 18 from the rail adaptor mounting part 16 when seen from the viewing direction 46, such that the rail 5 is horizontally moved away from the staircase 3 when compared to a stair lift 2 without adaptor system 4. The horizontal adapted rail distance 18 is measured between a vertical rail adaptor mounting centre line 43 of the rail adaptor mounting part 16 that extends through a rail adaptor mounting centre 44 of the rail adaptor mounting part 16 and the longitudinal rail axis 39 in horizontal direction at the rail support height 42 of said rail support mounting part 12 and parallel to the virtual vertical plane 45 when seen from the viewing direction 46. The vertical rail adaptor mounting centre line 43 extends vertically through a rail adaptor mounting centre 44 of the rail adaptor mounting part 16. In Fig. 2A - 2C, the rail protrusion distance 48 is reduced to zero. The horizontal adapted rail distance 18 is larger than the horizontal rail distance 13 (see Fig. 1). Subtracting the horizontal rail distance 13 from the horizontal adapted rail distance 18 yields the horizontal rail distance difference 23. The horizontal seat distance 11 compensates at least part of the horizontal rail distance difference 23, because the horizontal shift in the position of the rail due to the rail adaptors 14 is in the second horizontal direction 66 and the horizontal shift in the position of the seat due to the seat adaptor 15A, 15B, 15C is in the first horizontal direction 65, wherein the first horizontal direction 65 and the second horizontal direction 66 are mutually opposite directions. In the situation of the Figs. 2A - 2C, the horizontal seat distance compensates the horizontal rail distance difference completely. In other embodiments of the stair lift set, the horizontal seat distance 11 may compensate between 50% and 150% of the horizontal rail distance difference 23, in particular between 75% and 125%, more in particular between 90% and 110%. In the situation of the Figs. 2A - 2C, the horizontal seat distance is equal to the horizontal rail distance difference. In other embodiments of the stair lift set, the horizontal seat distance 11 is between 50% and 150% of the horizontal rail distance difference 23, in particular between 75% and 125%, more in particular between 90% and 110%.

The horizontal seat distance 11 does not need to completely compensate the horizontal rail distance difference 23 in specific applications. In some applications, it may be sufficient to over- or undercompensate, for example if there is some freedom in the position of the seat 8 relative to the carriage 7 while still allowing safe boarding and deboarding of the seat 8 at the top of the staircase 3. It may also be practically impossible to fully compensate the horizontal rail distance difference 23 with the horizontal seat distance 11, for example for a stair lift set 1 where the horizontal seat distance 11 is limited due to interference with other parts of the stair lift set 1 such as the rail 5 or the carriage 7. A potential reason for the horizontal seat distance 11 to differ from the horizontal rail distance difference 23 could be that the rail adaptors 14 are mounted to the staircase 3 at another position than the rail supports 6 would be mounted if no adaptor system 4 were used. This entails that only one size of rail adaptors 14 need to be produced for use with different sizes of seat adaptors 15A, 15B, 15C. The rail adaptors 14 may also be mounted to the staircase 3 at the same position as the rail supports 6. This allows easy installation of the stair lift set 1 , because the installation points of the stair lift set 1 on the staircase are in the same position as they would be without using the adaptor system 4.

The rail adaptor mounting parts 16 are supported by the rail mounting step treads 25, but they may instead and/or in addition be supported by the rail mounting step risers 26. The rail adaptor supporting part 17 is positioned at a horizontal adaptor distance 51 from the rail mounting step tread 25 of the rail mounting step 24 of the staircase 3. The rail adaptor support centre 54 of the rail adaptor supporting part 17 is positioned at a horizontal adaptor distance 51 from the mounting step tread end 52. The horizontal adaptor distance 51 is measured along a horizontal line between the mounting step tread end 52 and a vertical adaptor support centre line 62 that extends through the rail adaptor support centre 54 of the rail adaptor supporting part 17. The rail adaptor supporting part 17 may also be positioned such that it merely extends beyond the rail mounting step tread 25 along the second horizontal direction 66. This may be the case for a very small horizontal adapted rail distance 18.

Figs. 4 and 5 show a fourth and fifth embodiment of the stair lift set 1 according to the invention, wherein the rail adaptors 14 comprise a support member 27. This support member 27 supports the rail adaptor supporting part 17.

Fig. 4 shows support members 27 comprising support legs 28 that are supported on the support steps 29 directly below the rail mounting steps 24. The support legs may also be supported on a support step 29 further below a rail mounting step 24. The length of the support leg 28 substantially corresponds with the height difference 33 between the rail mounting step tread 25 and the support step tread 34 and the support leg 28 supports the rail adaptor supporting part 17 on the support step tread 34. The support leg 28 may have a variable length in order to adapt to different staircases 3.

Fig. 5 shows support members 27 which are angled support members 30. The angled support members 30 are supported on the rail mounting step risers 26 of the rail mounting steps 24. The angled support members 30 may also be supported on a riser of another step.

In Fig. 6, a sixth embodiment of the stair lift set 1 according to the invention is shown wherein the rail 5 is offset even further than in Figs. 2A - 2C. This provides even more room near the top of the staircase 3, because the top of the rail 5 is further away from the top of the staircase 3.

In Fig. 7, a seventh embodiment of the stair lift set 1 according to the invention is shown wherein the rail protrusion distance 51 of the rail protrusion 50 beyond the top of the staircase 3 is not reduced to zero but merely reduced. This may be advantageous if a small rail protrusion 50 is allowable, for example if an obstruction is present at a small distance from the top of the staircase 3. It may also be necessary to provide a smaller horizontal adapted rail distance 18, for example if there is no room near the bottom of the staircase 3 to install the rail 5 at a larger horizontal adapted rail distance 18.

Fig. 8 shows a top view of one of the rail adaptors 14 of Fig. 2A. The rail adaptor 14 comprises a rail adaptor mounting part 16 and a rail adaptor supporting part 17, which are offset with respect to each other. This allows mounting a rail support 6 on the rail adaptor supporting part 17 while the rail adaptor mounting part 16 is mounted to a staircase 3, effectively shifting the stair lift 2 with respect to the staircase 3. The rail adaptor mounting part 16 comprises rail adaptor mounting part connecting holes 56 and the rail adaptor supporting part 17 comprises rail adaptor supporting part connecting holes 57 in order to mount the rail adaptor to the staircase 3 and the rail support mounting part 12, respectively.

Figs. 9A - 9C show side views of the seat adaptors 15A, 15B, 15C of Figs. 2A - 2C, respectively. The seat adaptors 15A, 15B, 15C each comprise a first seat adaptor connecting part 35 comprising first seat adaptor connecting part holes 58 and a second seat adaptor connecting part 36 comprising second seat adaptor connecting part holes 59. The seat adaptors 15A, 15B, 15C are configured to be mounted between the seat 8 and the carriage 7 using connectors 61 and fasteners such as bolts.

The first seat adaptor connecting part 35 of the seat adaptor 15A is configured to be connected to the seat 8 with the first seat adaptor connecting part holes 58. The second seat adaptor connecting part 36 of the seat adaptor 15A is configured to be connected to the carriage 7 with the second seat adaptor connecting part holes 59. Bolts are placed in the first seat adaptor part connecting holes 58, the first seat adaptor part connecting holes 59, and the seat connecting holes 60.

The first seat adaptor connecting part 35 of the seat adaptor 15B is configured to be connected to the seat support 10 with the first seat adaptor connecting part holes 58. The second seat adaptor connecting part 36 of the seat adaptor 15B is configured to be connected to the carriage 7 with the second seat adaptor connecting part holes 59.

The first seat adaptor connecting part 35 of the seat adaptor 15C is configured to be connected to the seat 8 by connectors 61 with the first seat adaptor connecting part holes 58. The second seat adaptor connecting part 36 of the seat adaptor 15C is configured to be connected to the seat support 10 by connectors 61 with the second seat adaptor connecting part holes 59.