APPARATUS FOR TRANSPORTING A LOAD, IN PARTICULAR A STAIRLIFT

Abstract

An apparatus for transporting a load, in particular a stairlift, includes a frame displaceable along a rail, a load carrier rotationally mounted on the frame for rotation around a horizontal axis, an adjusting motor for rotating the load carrier relative to the frame around the horizontal axis, a rotation blocking device for blocking of the load carrier with respect to the frame in a braking operation mode, and a decoupling means to decouple the load carrier from the rotation blocking device and/or the frame from the rotation blocking device so that a limited amount of movement of the load carrier and/or the frame with respect to the rotation blocking device is allowed in the braking operation mode of the rotation blocking device. A resilient member resists at least part of said movement of the load carrier and/or the frame with respect to the rotation blocking device.

Claims

1. An apparatus for transporting a load, comprising: a frame displaceable along a rail; a load carrier which is rotationally mounted on the frame to be rotated around a horizontal axis; an adjusting motor arranged to rotate the load carrier relative to the frame around the horizontal axis; a rotation blocking device for blocking a rotational movement of the load carrier with respect to the frame in a braking operation mode of the rotation blocking device; a decoupling means configured to decouple the load carrier from the rotation blocking device and/or the frame from the rotation blocking device, such that a limited amount of movement of the load carrier and/or the frame with respect to the rotation blocking device is allowed in the braking operation mode of the rotation blocking device, and a resilient member for resisting at least part of said movement of the load carrier and/or the frame with respect to the rotation blocking device.

2. The apparatus of claim 1, wherein the decoupling means and/or the resilient member are at least partially integrated in the rotation blocking device.

3. The apparatus of claim 1, wherein the resilient member is configured for resisting a rotational movement of the load carrier with respect to the frame around the horizontal axis, as part of said limited amount of movement.

4. The apparatus of claim 3, wherein the decoupling means comprises mounting holes, provided in the rotation blocking device for connecting the rotation blocking device with the load carrier and/or the frame, the mounting holes being elongated in a tangential direction around the horizontal axis for allowing said rotational movement.

5. The apparatus of claim 4, wherein the resilient member is provided in at least one of the mounting holes.

6. The apparatus of claim 4, wherein: the load carrier is connected to the adjusting motor by means of fastening elements; the rotation blocking device comprises a first braking member, configured to be locked and unlocked relative to the frame by the rotation blocking device in the braking operation mode, the first braking member being interposed between the load carrier and the adjusting motor; and the mounting holes of the decoupling means include fastening holes provided in the first braking member which are configured to allow the fastening elements to pass through the first braking member.

7. The apparatus of claim 6, wherein: an alignment pin is arranged on the adjusting motor; the mounting holes of the decoupling means include an alignment hole provided in the first braking member which is configured to receive the alignment pin; and the resilient member is arranged in the alignment hole to engage the alignment pin in the tangential direction and an inner surface of the alignment hole.

8. The apparatus of claim 7, wherein the rotation blocking device comprises two resilient members, each engaging the alignment pin and opposite inner surfaces of the alignment hole.

9. The apparatus of claim 7, wherein the resilient member is a spring.

10. The apparatus of claim 6, wherein the rotation blocking device further comprises spacers located in the fastening holes which are configured to be movable within the fastening holes in the tangential direction and to receive the fastening elements

11. The apparatus of claim 6, wherein the first braking member is shaped as an annulus and is substantially concentric with the horizontal axis

12. The apparatus of claim 6, wherein the rotation blocking device further comprises: a second braking member connected to the frame; a third braking member arranged between the first braking member and the second braking member; and a movable retaining member which holds the third braking member and which is arranged to be moved relative to the second braking member, wherein the first braking member has a primary braking surface which is strip shaped and extends along at least a section of a circle around the horizontal axis, wherein the second braking member has a secondary braking surface which extends at a distance from the primary braking surface at an angle in such manner that the distance between the two surfaces varies, thereby forming a substantially wedge-shaped gap between the primary surface and the secondary surface having a wider part and a narrower part, the wedge-shaped gap widening in the tangential direction around the horizontal axis, wherein in a normal operation mode of the rotation blocking device, wherein the first braking member is unlocked relative to the frame, the third braking member is held in a fixed position relative to the second braking member by the retaining member such that it is positioned in the wider part of the wedge-shaped gap where it cannot engage both the primary braking surface and the secondary braking surface at the same time, and wherein in the braking operation mode of the rotation blocking device, wherein the first braking member is locked relative to the frame, the retaining member is arranged to be moved relative to the second braking member such that the third braking member moves to the narrower part of the wedge-shaped gap, thereby engaging both the primary braking surface and the secondary braking surface and blocking rotation of the second braking member in the tangential direction relative to the first braking member.

13. The apparatus of claim 12, wherein the movable retaining member is designed such that it forces the third braking member to move to the narrower part of the wedge-shaped gap when the retaining member is moved relative to the second braking member in the braking operation mode.

14. The apparatus of claim 12, wherein the rotation blocking device comprises a multitude of first and secondary braking surfaces forming substantially wedge-shaped gaps and a multitude of third braking members, each extending in a respective substantially wedge-shaped gap.

15. The apparatus of claim 12, wherein the third braking member has the form of a cylinder, and the axis of the cylinder extends parallel to both the primary and secondary braking surfaces.

16. The apparatus of claim 12, wherein the retaining member is held in position in normal operation by the force of an electrically powered electromagnet.

17. The apparatus of claim 12, wherein a resilient biasing member is arranged to move the retaining member from the fixed position in normal operation mode to the braking operation mode.

18. The apparatus of claim 1, wherein the frame is provided with support, guide and drive means arranged to engage the rail.

19. The apparatus of claim 1, further comprising position-maintaining means for maintaining the load carrier in a predetermined rotational position relative to the direction of gravity, which position-maintaining means comprise at least the adjusting motor.

20. The apparatus of claim 1, wherein the apparatus is a stairlift configured to transport a load from a first level to a second level.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will hereinafter be elucidated by means of illustrative examples with reference to the attached drawings, wherein:

[0033] FIG. 1 shows a perspective view of an exemplary stairlift;

[0034] FIG. 2 shows an exploded perspective view of a displaceable frame and a carrier for an exemplary stairlift as shown in FIG. 1, with an exemplary rotation blocking device mounted therebetween;

[0035] FIG. 3 shows a schematic front view of the rotation blocking device of FIG. 2 in normal operation mode;

[0036] FIG. 4 shows a schematic front view of the rotation blocking device of FIG. 2 in resting or non-operational mode;

[0037] FIG. 5 shows a schematic front view of the rotation blocking device of FIG. 2 in braking operation mode;

[0038] FIG. 6 shows an exploded perspective view of an example of the rotation blocking device of the apparatus of the first aspect of the disclosure; and

[0039] FIG. 7 shows a schematic front view of the rotation blocking device of FIG. 6.

DETAILED DESCRIPTION

[0040] FIG. 1 shows an exemplary system 1 configured for transporting a load, such as a person, from a first level to a second level. In the present example, the first level is for instance the bottom of the shown staircase 2, and the second level is the top of the staircase 2. The system 1 may comprise a rail 3 which is placed along a staircase 2 and which encloses an angle a with the horizontal H, and an apparatus 4, also referred to as stairlift 4, movable along rail 3 for transporting the load between the different levels. Rail 3, which in the shown example has a round cross-section, is supported by a number of posts 5 which are arranged distributed along staircase 2 and which are fixed to a protruding part extending along rail 3. Rail 3 is further provided with a propelling part in the form of a gear rack (not shown). Stairlift 4 comprises a frame 9 which is displaceable along rail 3 and on which a load carrier 10 is mounted, here in the form of a chair with a seat 11, back rest 12, armrests 13 and a footrest 14.

[0041] Chair 10 is connected to frame 9 by a rotatable shaft and fixation means for rotating around a horizontal axis, and arranged in frame 9 and carrier 10 is a level maintaining mechanism consisting of, among other parts, of an adjusting motor connected to said shaft so that the position of chair 10 can be kept constant at all times irrespective of the inclination of rail 3.

[0042] FIG. 2 shows a rotation blocking device disposed between the frame 9 and the load carrier 10, according to an example which is useful for understanding the claimed invention. The rotation blocking device comprises a first braking member 21, a second braking member 22, a plurality of third braking members 23 (see FIGS. 3-7), and a retaining member 24 for holding the third braking members 23 in position.

[0043] The first braking member 21 comprises a cylindrical outer surface 212 (see FIGS. 3-7) extending around the hollow shaft (not shown) which is to be placed in the hollow shaft socket 15. The first braking member 21 is rigidly connected to the load carrier 10 by bolts 213 extending through holes 214 in said body 10.

[0044] The second braking member 22 comprises a substantially cylindrical body extending around the cylindrical part 212 of the first braking member 21, such that it can rotate relative thereto. The second braking member 22 is rigidly connected to the frame 9 by bolts 221 extending through holes 222. A guide ring 224, which encloses the first braking member 21 in the axial direction, is provided on each side of the second braking member 22.

[0045] The second braking member 22 comprises recesses 223 in its inner circumferential wall around the cylindrical outer surface 212 of the first braking member 21, such that the surface of said recesses face the outer surface 212. As shown in FIGS. 3-5, the surface of the recesses 223 is shaped such that the surface of each recess 223 and said surface of the cylindrical part 212 form substantially wedge-shaped gaps 231, having a wider part in its upper region and a narrower part in its lower region. The guide ring 224 of the braking member 22 has a substantially circular shape, and comprises recesses which form guides 2243 that are shaped such that can they engage both outer ends of the third braking members 23 and guide the third braking members 23 away from the surface 212 when they are moved by the retaining member 24 to the upper extreme positions, as shown in FIG. 3 and as explained below.

[0046] The third braking members 23 have a cylindrical main body and a shaft extending from both ends. The holders 241 of the retaining member 24 have holes 249 in which the shafts of the third braking members 23 extend. The braking members 23 can freely rotate around the shafts.

[0047] The retaining member 24 comprises two holders 241, two lateral arms 242, a link 243 and a shaft 244. The shaft 244 is mounted on the load carrier 10 in such a manner that it can move in its axial direction, which direction is perpendicular to the horizontal axial direction of the first braking member 21 and the second braking member 22, and which axial direction is, in the example as shown, the vertical direction. The link 243 is attached to the shaft 244 and extends perpendicular to the shaft and is allowed to rotate around the axis of the shaft 244. One end of each of the two lateral arms 242 is attached to the outer end of the link 243 in such a manner that they can rotate around a horizontal axis which is parallel to the horizontal axial direction of the first braking member 21 and the second braking member 22, and such that they can rotate about an axis which is parallel to said axis of the shaft 244. The other outer ends of the lateral arms 242 are each attached to a respective holder 241, in such a manner that the holders 241 can rotate with respect to the arms 242 about an axis which is parallel to the horizontal axial direction of the first braking member 21 and the second braking member 22.

[0048] The holders 241 are for instance made of a flexible material, such as a flexible plastic material, such that they can easily deform when forces are exerted on different parts of the holder 241, in particular by the third braking members 23.

[0049] Detectors such as micro switches 245 detect the angular mutual orientation between the arms 242 and the holders 241, whereby an emergency braking action may be detected, such that the stairlift 4 may be put out of operation until maintenance has occurred.

[0050] The shaft 244, the holders 241 and the third braking members 23 that they hold are movable between two respective extreme positions. Two or more biased springs 246 may be provided, of which one end pushes against a third braking member 23, one on the right side and one the left side as seen in FIGS. 3-5, and the other end pushes against a stop surface in the recess 223 of the second braking member 22, thereby pushing said third braking member 23 and thereby the retaining member 24, that hold all third braking members 23, towards their first extreme position. Furthermore, an electromagnet 248 is provided, which is mounted on the load carrier 10. When, in the normal operation mode, the electromagnet 248 is powered, it pulls the shaft 244 of the retaining member 24 in its second extreme (upper) position, against the force of spring 246, thereby moving the holders 241 of the retaining member 24 and the third braking members 23 towards their second extreme position. If the electromagnet is not powered, the shaft 244 is allowed to move, and the spring 246 may push the holders 241 of the retaining member 24 and the third braking members 23 back towards their first extreme (lower) position.

[0051] Even though the first braking member 21 and its functions are here shown as being present on the inner ring-shaped member, and the second braking member 22 and its function are here shown as being present on the outer ring-shaped member, the locations along with the functions of the first and second braking member 21, 22 may be envisaged to be switched, such that, for example, the first braking member 21 and its functions are embodied by the outer ring-shaped member and the second braking member 22 and its functions are embodied by the inner ring-shaped member.

[0052] In the normal operation mode, as shown in FIG. 3, when the retaining member 24 is forced to be in the upper position by the electromagnet 248, and the retaining member 24 carry the shafts of the third braking members 23 such that their main bodies are forced to extend in the wider parts of the wedge-shaped gaps 231 and the third braking members are (just) lifted from the surface 212 by the guides 2243. In that position the first braking member 21 and the second braking member 22, and thereby the frame 9 and the load carrier 10, can freely rotate relative to each other.

[0053] As shown in FIG. 4, in a resting or non-operational mode when the stairlift is not moving, the electromagnet is unpowered, and the retaining member 24 with the holders 241 is forced towards the lower position by the spring 246, whereby the shafts of the third braking members 23 move towards the narrower part of the wedge-shaped gaps 231 at both the left and right sides of FIG. 4, such that the cylindrical surfaces of the main bodies of the third braking members 23 each touch both the surface 212 of the first braking member 21 and the surface 223 of the second braking member 22. In that position the friction of the main bodies of the third braking members 23, prevents rotation between the first braking member 21 and the second braking member 22, and thereby the frame 9 and the load carrier 10.

[0054] In the emergency braking operation mode the electromagnet is also unpowered, for instance in reaction to a signal from a sensor that detects tilting of the load carrier, and the retaining member 24 with the holders 241 is first forced towards the lower position by the spring 246, as in the resting mode of FIG. 4, whereby the shafts of the third braking members 23 move to the narrower part of the wedge-shaped gaps 231 at both the left and right sides. However, due to (undesired) rotation of the load carrier 10 and the first braking member 21 attached to it, the third braking members 23 on either the left or the right side (depending on the direction of rotation of the first braking member 21) will move further into the narrow side of the gap, which may cause deformation of the materials of for instance the second braking member (as shown in FIG. 5).

[0055] Said movement of the third braking members 23 will cause their holder 241 to move and thereby also move the other holder 241 of the retaining member 24 with the other third braking members 23 as shown in FIG. 5. In that position the friction of the main bodies of the third braking members 23, and the possible deformation of materials, prevent rotation between the first braking member 21 and the second braking member 22, and thereby the frame 9 and the load carrier 10.

[0056] Thereby the undesired rotation of the load carrier 10 is stopped.

[0057] The flexibility of the holders 241 allow that in the braking operation mode all the third braking members 23 in the respective holder can and will be engaged by the surface 212 of the first braking member 21 and the respective surfaces 223 of the second braking member 22, as they are not necessarily held in a mutually fixed position as would be the case with a stiff retaining member.

[0058] In FIGS. 6 and 7, an exemplary rotation blocking device of the apparatus 4 of the first aspect of the disclosure is shown. Elements that are similar or identical to the device of FIGS. 2-5 are denoted with the same numerals. The main difference of the rotation blocking device of the apparatus 4 of FIGS. 6 and 7 with respect to the one of FIGS. 2-5 is related to the first braking member 21.

[0059] The first braking member 21 is provided with fastening holes 214E which are elongated as compared to the holes 213 of FIGS. 2-5. The elongation of the fastening holes 214E is substantially in the tangential direction T around the horizontal axis X. The holes 214E are provided with spacers 2140, which have roughly a washer shape. The spacers 2140 are configured to receive the fastening elements 213 (see FIG. 2) with which the load carrier 10 can be fastened to the frame 9 (particularly to the adjusting motor). The spacers 2140 can move within the holes 214E, such that the fastening elements 213 can move in tangential direction T relative to the first braking member 21.

[0060] The first braking member 21 is further provided with two alignment holes 215 which are configured to receive alignment pins 150 of the adjustment motor. The alignment holes 215 are elongated in tangential direction T, such that the alignment pins 150 can move in tangential direction T relative to the first braking member 21. The alignment pins 150 are further biased towards the center of the alignment holes 215 through resilient members, particularly compression springs 216. As both the fastening elements 213 positioned through the spacers 2140 and the alignment pins 150 are rigidly connected to the adjustment motor, the fastening elements 213 and spacers 2140 are also biased towards the center of the fastening holes 214E.

[0061] When the first braking member 21 is locked by engagement of the third braking members 23, a rotational force applied to the load carrier 10 will cause movement of the fastening elements 213 and the alignment pins 150 in fastening holes 214E and alignment holes 215, respectively. This movement is damped through the springs 216 acting against the movement of the alignment pins 150 in the alignment holes 215, until the relevant springs 216 are fully compressed. This means that the effect of the rotational force applied to the load carrier 10 on the clamping of the third braking member 23 between the first and second braking members 21, 22 is decreased, as the rotational force is partially absorbed by the springs 216. Accordingly, a rotational force applied to the load carrier 10 in the braking operation mode of the rotation blocking device is not directly transferred to the braking mechanism formed by the first, second and third braking members 21, 22, 23. Accordingly, the chance that the braking mechanism becomes jammed or stuck to a certain degree or wear such as deformations, due to such rotational force applied to the load carrier 10, is effectively decreased. When the first braking member 21 is released (normal operation mode), the springs 216 cause the alignment pins 150 and fastening elements 213 to re-center in the alignment holes 215 and fastening holes 214E, respectively.

[0062] In accordance with the above, regarding FIGS. 6 and 7, the elongate fastening holes 214E and elongate alignment holes 215 may form part of an example of a decoupling means of the first aspect of the present disclosure.

[0063] The illustrative embodiments or examples described above are not to be construed as limiting the scope of protection, which is determined by the appended claims.