Patent Application
20220081257
The disclosure relates to a low-profile rail for a stairlift and the method forming same.
Stairlifts (also referred to as chair lifts, stairway elevators, and other, similar names) transport people and/or other cargo up and down inclined paths such as stairways. Stairlifts include a rail and a carriage. The carriage is carried by the rail and movable along the rail.
The carriage includes a frame which may include rollers which ride on the rail, a load support attached to the frame and supporting a load, such as a chair or wheelchair platform, and a carriage drive attached to the frame to drive the frame and load support along the rail. The carriage drive may include a motor and a rack and pinion, screws, chains, cables, belts, and the like driven by the motor to cause the carriage and its associated load support to move along the rail. The load support is rotatably connected to the frame by a rotation device, such that load support rotates about a horizontal axis relative to the carriage. A control unit controls the rotation device, such that the load support is positioned in a desired orientation relative to a horizontal plane. The rotation device includes a motor and a rotator, where the motor is operatively connected to the load support via the rotator to cause rotation of the load support relative to the carriage about the horizontal axis.
The rail is mounted adjacent to or on the stairs and the carriage is attached to the rail. A person seated on the load support or cargo loaded on the load support may be moved up or down the stairway along the rail. The rails may be straight or curved.
Adapting the rail to a particular stairway configuration often requires rails having a wide range of shapes to navigate the person seated on the chair lift over and around stair landings, changes in stair directions or around spiral shaped staircases, while maintaining close proximity to the wall supporting the rail, which demands inward and outward curves having various radii. This has led to the custom-manufacturing of a large number of custom-made rail sections, which has added considerably to the overall cost of, and pre-planning for, the installation.
While bending rails into various shapes demands use of a malleable material for manufacture of the rails, the teeth in the rack portion of the rail need to retain their shape and gap distances between teeth despite the forces exerted on the teeth by the pinion of the carriage drive. This has resulted in compromises between the malleability of the rail and the malleability of the teeth in the rack.
These and other problems are solved by the invention as described below.
One aspect of the invention is a rail segment for a stairlift comprising a tube having an elongated shape made of a first material, the tube comprising a first end, a second end, and a slot extending in a longitudinal direction from the first end to the second end; a rack made of a second material, the rack comprising a first end and a second end, wherein the rack has a shape which fits within the slot; a first anchor securing the rack within the slot at, or adjacent to, the first end of the tube; and a second anchor securing the rack within the slot at, or adjacent to, the second end of the tube.
Another aspect of the invention is a rail for a stairlift comprising a first rail segment and a second rail segment, wherein each rail segment comprises a tube having an elongate shape made of a first material, the tube comprising a first end, a second end, and a slot extending in the longitudinal direction from the first end to the second end, a rack made of a second material, the rack comprising a first end and a second end, wherein the rack has a shape which fits within the slot, a first anchor securing the rack within the slot at, or adjacent to, the first end of the tube, and a second anchor securing the rack within the slot at, or adjacent to, the second end of the tube, wherein the first end of the tube of the first rail segment abuts the second end of the tube of the second rail segment; a bracket links the first end of the tube of the first rail segment and the second end of the tube of the second rail segment; and a plurality of anchors secure the bracket to the tube of the first rail segment and to the tube of the second rail segment.
A further aspect of the invention is a method of manufacturing a curved rail segment for use in a stairlift rail system, the method comprising: providing a straight tube having an elongate shape comprising a first end, a second end, and a slot extending from the first end to the second end, wherein the tube is made of a first material; providing a rack having an elongate shape comprising a first end, a second end, a base and a plurality of teeth extending from the base, the rack being made of a second material which is different from the first material; inserting the rack into the slot; anchoring the first end of the rack at, or adjacent to, the first end of the tube; bending and/or twisting the anchored rack and tube; and anchoring the second end of the rack at, or adjacent to, the second end of the tube.
A further aspect of the invention is a kit for manufacturing a curved rail segment for use in a stairlift rail system, the kit comprising: a plurality of rail segments, wherein each rail segment comprises a tube having an elongate shape made of a first material, the tube comprising a first end, a second end, and a slot extending in the longitudinal direction from the first end to the second end, a rack made of a second material, the rack comprising a first end and a second end, wherein the rack has a shape which fits within the slot of each tube and has a length greater than the length of one or more of the plurality of rail segments, a plurality of anchors for securing the rack within the slot and a plurality of brackets for linking the plurality of rail segments to each other end-to-end.
Many aspects of the disclosure can be better understood with reference to the following drawings. While several implementations are described in connection with these drawings, the disclosure is not limited to the implementations disclosed herein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents.
While the disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that as illustrated and described herein. Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity. It will be further appreciated that in some embodiments, one or more elements illustrated by way of example in a drawing(s) may be eliminated and/or substituted with alternative elements within the scope of the disclosure.
The term “tube” means a hollow profile having a length greater than its maximum cross-section. The tube preferably has an hourglass-shaped cross-section.
The term “slot” means an elongated groove or aperture having a length corresponding to the length of the tube for accepting a portion of a rack suitable for engaging the slot. The slot is preferably has a cross-sectional profile shape having retaining surfaces capable of retaining the rack on the tube by engaging with a corresponding cross-sectional profile shape of the rack along the length of the slot. In a particular embodiment, the cross-sectional profile shape is an inward outline of a T-shape.
The term “rack” means a profile having an elongate shape having a length and a plurality of protrusions extending from a surface thereof, wherein the protrusions occur at regular intervals over the entire length of the rack for engagement with a pinion. The rack preferably has a cross-sectional profile shape along the length of the rack opposite the surface having a plurality of protrusions corresponding to the shape of the slot for retaining the rack in the slot. In a preferred embodiment, the cross-sectional profile shape has lateral extensions perpendicular to a longitudinal direction for engaging with the cross-sectional profile of the slot. In a particular embodiment, the cross-sectional shape is T-shaped.
The term “anchor” refers to a device or material capable of fixing the rack to the tube. Examples of anchors include threaded bolts and welds. When the slot is capable of retaining the rack, the anchor may be a threaded bolt and a threaded opening in the tube suitable for screwing the bolt into the tube toward a rack retained in the slot for pressing the rack against the retaining surfaces of the slot.
A rail 20 which forms part of a stairlift 22, and a method forming same are provided. The stairlift 22 is also referred to as a chair lift, stairway elevator, rail elevator, and other similar names. The rail 20 is mounted along a stairway 24 or other stairlift travel path, and the stairlift 22 further includes a carriage 26 mounted on the rail 20 for operation to move a load on the carriage 26 along the rail 20. The stairlift 22 provides smooth transitions through turns, curves, bends and other changes in the rail 20.
The rail 20 may include inclines, declines, various types of curves (including helical twists, turns and vertical elevation angle changes) and/or other changes in direction and/or orientation. Thus, various curves (helical, vertical, horizontal and combinations thereof) must be negotiated by the carriage 26. An angle change transitions the carriage 26 elevationally from one incline/decline angle to another. There are two types of angle changes—“going in” angle changes and “going out” angle changes. A “going in” angle change is an angle change that starts from a steeper angle and transitions to a flatter incline. A “going out” angle change is an angle change that starts from a lower degree and transitions to a higher degree incline. “Turns” transition the carriage 26 around a corner (horizontal bend) in a plan view. There are two primary types of turns and each primary type of turn has a corresponding secondary set. During an “inside turn” a rider's feet swing widely while the rider's back is closer to the turn's pivot point. In general, the rail 20 may be as close as possible to a wall to which the rail 20 is mounted to allow for maximum clearance for ambulatory people in the stairway 24 or other stairlift travel path. Inside turns often rotate the rider 90° or 180° in the plan view. A “helical turn” introduces an incline or elevation change while turning corners in connection with inside and outside turns (similar to a corkscrew or coil spring). A gooseneck or drop-nose configuration can also be provided which has a going in angle change, with an extremely steep start angle (e.g., vertical) that transitions to the incline of the stairway 24 or other stairlift travel path. The gooseneck or drop-nose configuration provides a low cargo carrying position height position relative to a floor at a base of the stairway 24 or other stairlift travel path, and a short extension away from a first step riser of the stairway 24 or other stairlift travel path.
The carriage 26 includes a frame 28 which may include rotatable rollers 30, 32, 34, 36, 38 mounted thereon and which ride on the rail 20, a load support 40 attached to the frame 28 and supporting the load, and a motor driven toothed gear 42 rotatably attached to the frame 28 and engaged with the rail 20 to drive the carriage 26 along the rail 20. The load may be, for example, an individual rider and/or cargo. The frame 28, with the exception of where the rollers 30, 32, 34, 36, 38 contact the rail 20, and the motor driven toothed gear 42 may be covered by a shroud 44.
The load support 40 is rotatably connected to the frame 28 by a rotation device (not shown) which rotates the load support 40 about a horizontal axis relative to the frame 28 to maintain the load in an upright position as the carriage 26 traverses along the rail 20.
The rail 20 includes one or more rail segments 50 that fit within a given stairway 24 or other stairlift travel path. The one or more rail segments 50 can be straight, or can be curved in one or more ways, for example, being twisted, horizontally curved, vertically curved, and combinations thereof. Each rail segment 50 has a first end 50a, an opposite second end 50b, and a longitudinal central axis 52 that extends between the ends 50a, 50b. A length of the rail segment 50 is defined between the ends 50a, 50b. When more than one rail segment 50 is provided, the rails segments 50 are connected at adjacent ends 50a, 50b at a joint 54.
One rail segment 50 and its method of formation is described, with the understanding that the other rail segments 50 are identically formed.
The rail segment 50 includes an elongated tube 56 and an elongated rack 58 carried on the tube 56. The rack 58 is separately manufactured from the tube 56 and attached thereto as described herein.
The tube 56 is formed from a durable, yet suitably malleable material. In some implementations, the tube 56 is formed from aluminum or an aluminum alloy.
When the tube 56 is in an unbent condition or untwisted condition, the tube 56 has a constant cross-sectional shape along its length from a first end 56a to a second end 56b thereof. In the unbent condition or untwisted condition, the tube 56 preferably has an hourglass cross-sectional shape, as shown in
The following cross-sectional shape is described when the tube 56 is in the unbent condition and untwisted condition. The tube 56 has a planar top surface 60 forming a first roller engagement surface and a bottom surface 70. In one embodiment, the bottom surface 70 is planar and is parallel to the top surface 60. An outer side surface 72 extends between the top and bottom surfaces 60, 70 and faces away from the wall when the rail segment 50 is mounted on the stairway 24. An inner side surface 74 extends between the top and bottom surfaces 60, 70 and faces the wall when the rail segment 50 is mounted on the stairway 24. A vertical centerline 76 is defined between the top and bottom surfaces 60, 70 and splits the tube 56 into halves with the outer side surface 72 on one side of the centerline 76 and the inner side surface 74 on the other side of the centerline 76.
The outer side surface 72 has the surface 62 which is curved and extends along a radius line, an upper curved surface 78 that extends between an upper end of the surface 62 and the top surface 60, the surface 64 which is curved and extends along a radius line, a lower curved surface 80 that extends between a lower end of the surface 64 and the bottom surface 70, and a planar side surface 82 which extends between a lower end of the surface 62 and an upper end of the surface 64. The surfaces 62, 64 may have the same radius. The surface 62 provides a second roller engagement surface. The surface 64 provides a third roller engagement surface. A groove 84 may be formed in the lower curved surface 80 and extends longitudinally along the rail segment 50 to permit mounting of the rail segment 50 on a stairway 24 or other stairlift travel path using a suitable mount 86. A horizontal centerline 83 is defined between the surface 68, 82 and splits the tube 56 into halves and is perpendicular to the centerline 76.
In one embodiment, the inner side surface 74 is the mirror image of the outer side surface 72 with the exception of a longitudinal retaining slot 88 that extends the entire length of the tube 56 from the first end 56a to the second end 56b thereof and divides the inner side surface 74 into an upper portion 90 and a lower portion 92.
Accordingly, the inner side surface 74 has the surface 66 which is curved and extends along a radius line, an upper curved surface 94 that extends between an upper end of the surface 66 and the top surface 60, a lower curved surface 96 which is curved and extends along a radius line, a lower curved surface 98 that extends between a lower end of the surface 96 and the bottom surface 70, and the surface 68 which is planar, forms a side surface, and extends between a lower end of the surface 66 and an upper end of the surface 98. The surfaces 66, 96 may have the same radius, and may have the same radius as surfaces 62, 64. The surface 66 provides a fourth roller engagement surface. The surface 68 provides a fifth roller engagement surface. In an embodiment, the surface 68 in the upper portion 90 provides the fifth roller engagement. In an embodiment, the surface 68 in the lower portion 92 provides the fifth roller engagement. A groove 100 may be formed in the lower curved surface 98 and extends longitudinally along the rail segment 50 to permit mounting of the rail segment 50 on a stairway 24 or other stairlift travel path using a suitable mount 86. In an embodiment, any surface of the tube 56 that does not form a roller engagement surface can take shapes other than those specifically shown.
In an embodiment, the longitudinal retaining slot 88 is at the midpoint of the inner side surface 74 such that the inner side surface 74 is divided into an upper half and a lower half. In an embodiment, the longitudinal retaining slot 88 is offset from the midpoint of the inner side surface 74 such that the upper portion and the lower portions are unequal. As shown, the retaining slot 88 includes walls 104 forming an enlarged longitudinally extending cavity section 106 which is connected to the inner side surface 74 by walls 108 forming a longitudinally extending necked-down section 110, such that a generally T-shaped slot is formed.
The planar top surface 60 accommodates the use of a roller 30 having a cylindrical outer profile as shown in
Internal longitudinally extending cavities or channels 112 may also be provided in the tube 56 to permit deployment of wiring and/or other apparatus to assist in operating the stairlift 22. The cavities or channels 112 also assist in reducing the weight of the rail 20. Wiring holes 114 may also be provided to allow for wiring and/or other apparatus to be threaded through a given rail segment 50 and into the cavities or channels 112.
The rack 58 is formed from a durable material and may be a more rigid material from that which the tube 56 is formed, but in some embodiments, is more robust than the tube 56. In some implementations, the rack 58 is formed from steel.
When the rack 58 is in an unbent condition or untwisted condition, the rack 58 has a constant cross-sectional shape along its length. In the unbent condition or untwisted condition, the rack 58 has a longitudinally extending base section 116 which extends from a first end 58a of the rack 58 to a second end 58b of the rack 58. The base section 116 is generally rectangular in cross-section. A plurality of spaced apart protrusions 118 extend from a first side of the base section 116, and a plurality of spaced apart teeth 120 extend from a second side of the base section 116. Side surfaces 122, 124 extend between the protrusions 118 and the teeth 120. The side surfaces 122, 124 are planar with the exception of a longitudinally extending groove 126, 128 in each side surface 122, 124; the grooves 126, 128 may align with each other. The grooves 126, 128 are slightly larger than the walls 108 forming the necked-down section 110.
The rack 58 is mated with the tube 56 by the protrusions 118 being seated within the enlarged cavity section 106, and the longitudinally extending grooves 126, 128 being engaged with the walls 108 forming the necked-down section 110 of the retaining slot 88. The engagement of the longitudinally extending grooves 126, 128 being engaged with the necked-down section 110 prevents the rack 58 from being pulled outwardly from the inner side surface 74 of the tube 56. As a result, the teeth 120 extend outwardly from the inner side surface 74.
In some embodiments, the rack 58 is secured to the tube 56 by anchors 130, 132 such as screws or welds. In some embodiments, access to/for the anchors 130, 132 are provided through one or more access holes 134 in the tube 56. Anchor 130 secures the first end 58a of the rack 58 at or adjacent to the first end 56a of the tube 56, and anchor 132 secures the second end 58b of the rack 58 at or adjacent to the second end 56b of the tube 56.
Where a stairway 24 or other stairlift travel path has been measured in advance, customized rail segments 50 can be fabricated offsite to provide a minimally-intrusive rail 20 that is easily and quickly installed for a stairlift 22 operating in the pre-measured stairway 24 or other stairlift travel path.
Any suitable bending process can be used to create the curved rail segment 50. Freeform bending, and push bending in particular, are non-limiting examples of bending processes that can be employed in some implementations, allowing the straight composite rail segment stick to be shaped kinematically.
As seen in
In an embodiment, the joint 54 may be simultaneously secured and reinforced by blocks 136, such as L-shaped brackets. One or more blocks 136 are secured in place in the cavities or channels 112 in each rail segment 50 to link the tube 56 of the one rail segment 50 to the tube 56 of the adjacent rail segment 50. Anchors 138, such as screws, welds and the like, are used to attach the blocks 136 to the adjacent tubes 56 through holes 140 in the tube 56. In some embodiments, the blocks 136 may also reinforce and/or rigidize the abutment of the adjacent tubes 56.
In an embodiment, the mount 86 includes cleats 142 and a mounting bracket(s) 144 which mount the rail segment 50 to the stairway 24 as shown in
Many modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which these disclosed embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific embodiments disclosed herein and that modifications and other embodiments are intended to be included within the scope of the disclosure. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the disclosure. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated within the scope of the disclosure. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
While particular embodiments are illustrated in and described with respect to the drawings, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the appended claims. It will therefore be appreciated that the scope of the disclosure and the appended claims is not limited to the specific embodiments illustrated in and discussed with respect to the drawings and that modifications and other embodiments are intended to be included within the scope of the disclosure and appended drawings. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the disclosure and the appended claims.
This application claims the domestic benefit of U.S. Provisional Application Ser. No. 62/855,119 filed on May 31, 2019 and U.S. Provisional Application Ser. No. 62/886,620 filed on Aug. 14, 2019.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US20/34819 | 5/28/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62855119 | May 2019 | US | |
| 62886620 | Aug 2019 | US |
