STAIRLIFT

Abstract: Wheelchair lift that is travelling along at least one drive rail (3), preferably arranged along a staircase (1), comprising a frame (5), which supports a load-carrying platform (5.2), the frame (5) showing a carrying frame section (5.1) and comprising an in the vertical plane rotatable sub-frame (6) that carries one or more carrying members or guide rollers (7) that are connected with the drive rail (3). A drive motor (8) that is connected with the drive rail (3) via a drive pinion (8.2) is also carried by a sub-frame, preferably the same sub-frame (6) that carries the carrying members. Preferably the sub-frame (6) or the sub-frames are rotatable around their centre.

Description: Stairlift TECHNICAL FIELD The present invention relates to a wheelchair lift, which is travelling along at least one drive rail arranged along a staircase. The wheelchair lift comprises a frame that supports a load-carrying platform and shows a carrying frame section comprising a sub-frame which is rotatable around its centre and which carries one or more carrying members, e.g. guide rollers which are in contact with the drive rail. BACKGROUND TECHNICS A wheelchair lift according to the preamble is known from the U.S. Patent 3,966,022. The sub-frame in the known wheelchair lift is rotatable from a neutral position for about 15° in either direction whereby the guide rollers, which carry the wheelchair lift, may be adjusted for a drive rail with an inclination that may vary up to 30° with one and the same type of assembling in the respectively left and right side in a staircase. To enable the assembling of a left-handed wheelchair lift to the right side in a staircase, both the load carrying platform and the sub-frame have to be disassembled and moved to the opposite side of the carrying frame section. Even in that position the known wheelchair lift permits mounting only for staircases with an inclination that may vary up to about 30°. The cause why the sub-frame can not be rotated more than within a certain interval is, that the driving motor is mounted to the carrying frame section .of the frame and is separated from the sub-frame. The driving motor is connected to a rack of the drive rail via a reduction gearbox and a pinion, the position of which is adjustable within a limited interval by adjusting the attachment of the reduction gear box in slots in a brace of the carrying section of the frame. The position of the driving motor precludes a bigger rotation of the sub-frame. Thus there is a motive to eliminate the disadvantages of the known wheelchair lift so that the wheelchair lift may be mounted optionally at all inclinations of staircases, even horizontally and to the left as well as to the right in a staircase and not any or some of its vital parts have to be disassembled, moved and reassembled. DESCRIPTION OF THE INVENTION The object of the present invention is to achieve a wheelchair lift, preferably intended for the transportation of wheelchairs between different floors or the like, which permits mounting in staircases of different inclinations in a better way than hitherto. As said in the preamble the wheelchair lift according to the invention is travelling along a drive rail that shows the same inclination as the inclination of the staircase and comprises a frame carrying platform, which is horizontal in travelling position. The frame shows a carrying frame section comprising a sub-frame, which carries one or more carrying members, e.g. sliding members or guide rollers, upon which the wheelchair lift is travelling along the drive rail. The sub-frame is rotatable around its centre and is adjustable so that the platform gets horizontal at different inclinations of the drive rail upon which the guide rollers are running. Preferably the sub-frame also carries a driving motor which is connected with the drive rail or a corresponding separate rail via a driving wheel. The driving motor also can be arranged on a separate, rotatable sub-frame. By placing the driving motor on the sub-frame the guide rollers and the driving motor may be rotated as a unit and adjusted in an optional position within 360°, which implies, that the wheelchair lift can be mounted to the left as well as to the right in a staircase without any parts needing to be disassembled, moved and reassembled. It lies within the scope of the invention also to mount the drive rail in an inclination that is separated from the inclination of the staircase and also in a place not showing any staircase at all. The device also may be mounted with the drive rail horizontally or vertically and constitutes then an ordinary lift. The wheelchair lift according to the invention also comprises a drop safety device, which is arranged to stop a free and uncontrolled motion of the frame and which may be arranged on the sub-frame with the guide rollers and/or the driving motor or on a separate sub- frame . The characteristics concerning the invention are evident from the claims. Further features and characteristics are evident from the description to the drawings subsequently. DESCRIPTION TO THE DRAWINGS The invention is described subsequently in connection with the enclosed drawings. Fig. 1 shows schematically a wheelchair lift seen from the side from which the support platform of the lift is protruding and in a direction of the wall along which the lift is travelling. Fig. 2 shows an assembly drawing of the mounting and travelling mechanism. Fig. 3 shows a sectional view of the driving device of the wheelchair lift. Fig. 4 shows the drop safety device of the wheelchair lift seen in a vertical plane. Fig. 5 shows the drop safety device according to fig. 4 in a section along line II-II in fig. 6. Fig. 6 shows the drop safety device according to fig. 4 in a section along line I-I in fig. 4. The wheelchair lift as shown in figs. 1-3 is arranged left-handed in a staircase 1, shown dash dotted in fig. 1, along one of which walls 2 are arranged partly a drive rail 3 and partly a support rail 4, running parallel with the latter. The drive rail 3 and the support rail 4 have an inclination that corresponds to the inclination of the staircase 1. The wheelchair lift comprises a frame 5 consisting of a vertical back plate 5.1, which at the bottom carries a platform 5.2 that is folding between a horizontal position, in which the lift can be used for transportation, and a vertical position, in which the staircase is available for pedestrians. The back plate 5.1 of the frame 5 shows a centrally arranged circular sub-frame 6 that is rotatable around its centre in relation to the back plate 5.1 and lockable in relation to it. The sub-frame 6 carries two upper and two lower guide rollers 7, arranged in bearings in the sub-frame 6 upon which the wheelchair lift travels along the upper part 3.1 of the drive rail 3. The wheelchair lift is driven by an electric motor 8 via a reduction gear 8.1 and a first pinion 8.2 that bears against a rack 3.2 at the lower section of the drive rail 3. The electric motor 8 and the gear 8.1 are fixedly mounted in the sub-frame 6 and therefor follow the rotary motion of the sub-frame 6 when it is rotated into the desired inclination for the guide rollers 7. A drop safety device 9 is centrally arranged in the sub-frame 6 and is connected with the rack 3.2 of the drive rail 3 via a second pinion. The drop safety device 9 is arranged to block the rotation of the second pinion in case of an uncontrolled downward motion of the lift. The sub-frame 6 is rotatable 360° so that the guide rollers 7 can be brought to incline upward to the right, as shown in fig. 1, or upward to the left, which involves that the frame 5 may be mounted both on the left side and on the right side in a staircase without any parts changing in the wheelchair lift. On fig. 2 the sub-frame β is shown in a horizontal position, which, however, is not appropriate to utilise when the wheelchair lift is mounted in a staircase. Fig. 2 shows also the clamping member 10 for fixation of the sub-frame 6 in a desired position and the folding devices 11 to pivot the platform 5.2 up and down. The wheelchair lift shows also a safety bolt 12 that is arranged at each end of the platform 5.2, each safety bolt 12 being connected via a mechanism 13 to a folding ramp 5.4 at each end of the platform 5.2. When the safety bolt 12 is turned up, shown on the left side of fig. 2, the ramp 5.4 is turned down by its own weight. When the safety bolt 12 is turned down, shown on the right side of fig. 2, the ramp 5.4 gets turned up effected by the mechanism 13. The drop safety device 9, shown in fig. 2, is also shown enlarged in figs. 4-6. The drop safety device 9 comprises an axle 9.1 that on one of its ends carries a pinion 9.2, which in its turn is connected with the rack 3.2. The axle 9.1 is mounted in a housing 14 that is fixedly attached to the sub-frame 6. When the wheelchair lift is moving, the other end of the axle 9.1 rotates in a freewheel hub 9.3 at a sleeve-shaped portion 14.1 protruding from the housing 14, the outside of which showing four arc-shaped roller ways 14.2 for rolls 14.3. The freewheel hub 9.3 is partially surrounding the sleeve-shaped portion 14.1 and shows corresponding internal arc-shaped roller ways 9.4 whereby each roll 14.3 rests in a slit with sideways diminishing height. In the centre of the freewheel hub 9.3 and at the other end of the axle 9.1, a centrifugal clutch 9.5 is arranged which shows two segment-shaped centrifugal weights 9.6, each of which at one of their ends are pivoting around their axle 9.7. Each centrifugal weight 9.6 shows an outwardly rotatable end that in a certain over rotation speed of the axle 9.1 is brought in contact with a stop face 9.8 on the freewheel hub 9.3 and turns the latter in the rotation direction, whereby the roll slit diminishes so that the rolls 14.3 lock the hub by wedging. The centrifugal weight 9.6 to the left on fig. 4 is intended to lock when the freewheel hub 9.3 rotates clockwise and the one to the right is intended to lock when the rotation is counter-clockwise. In normal operation the freewheel hub 9.3 is kept An a neutral position by means of a spring-loaded pivot 15 that is arranged in connection with the housing 14 and to project into the conical notch 9.9 in the freewheel hub 9.3. When the centrifugal clutch is activated, the spring action onto the pivot 15 is overcome, the freewheel hub 9.3 being rotated. The freewheel hub 9.3 is kept in place on the protruding sleeve-shaped portion 14.1 by means of resilient pins 16. Through the freewheel hub 9.3 in the drop safety device 9, a fast but yet soft retardation of the wheelchair lift is obtained in case of any possible breakdown and uncontrolled downward motion. It lies within the scope of the invention to arrange the driving motor 8 on a separate, second sub- frame, not shown in the figures, which is rotatable alone or together with the first sub-frame 6 with guide rollers 7. It also lies within the scope of the invention to replace the guide rollers 7 with supporting members of another kind, e.g. in the shape of gliding members, not shown in the figures. It lies also within the scope of the invention to arrange the drop safety device 9 upon either of the mentioned sub-frames or upon a separate sub-frame .

Claims: CLAIMS 1. Wheelchair lift that is travelling along at least one drive rail (3) , preferably arranged along a staircase (1), comprising a frame (5), which supports a load-carrying platform (5.2), the frame (5) showing a carrying frame-section (5.1) which comprises an in the vertical plane rotatable sub-frame (6) that carries one or more carrying members or guide rollers (7) that are connected with the drive rail (3) , the frame carrying a drive motor (8) that is connected with the drive rail (3) via a drive pinion (8.2) for driving the travelling of the wheelchair lift and the carrying members or guide rollers (7) and the drive motor (8) being arranged upon the same sub-frame, c h a r a c t e r i z e d in that the sub-frame (6) is rotatable clockwise as well as counter-clockwise from a initial position where the guide rollers (7) are set for a horizontal drive rail (3) so that the wheelchair lift can be mounted on the right side as well as on the left side in a staircase. 2. Wheelchair lift according to claim 1, c h a r a c t e r i z e d in that sub-frame (6) is rotatable 360° around its centre. 3. Wheelchair lift according to claim 1 or 2, c h a r a c t e r i z e d in that the sub-frame (6) is continuously rotatable and lockable to the carrying frame member (5.1) by means of clamping members (10). 4. Wheelchair lift according to any of the claims 1-3, c h a r a c t e r i z e d in that the drive motor (8) is connected with a rack (3.2) arranged along the drive rail (3), via a first pinion (8.2) the rotation axis of which is perpendicular to the plane through the sub-frame (6) and coincides with the rotary axle of the sub-frame (6) . 5. Wheelchair lift according to claim 4, c h a r a c t e r i z e d in that a drop safety device (9) is arranged upon the sub-frame (6) and is connected with the rack (3.2) via a second pinion (9.2) . 6. Wheelchair lift according to claim 5, c h a r a c t e r i z e d in that the drop safety device (9) comprises an axle (9.1) that is mounted in a housing (14) connected with the sub-frame (6) and that at one end carries the second pinion (9.2) and at the other end carries a centrifugal clutch (9.5) that is rotatable in a freewheel hub (9.3) that is in connection with and that on engagement will lock the axle (9.1) in relation to the housing (14) . 7. Wheelchair lift according to claim 6, c h a r a c t e r i z e d in that the freewheel hub comprises rolls (14.3), arranged in a slit with sideways diminishing height between a portion (14.1) protruding from the housing (14) and the freewheel hub (9.3) and that from a neutral position are movable in either direction in the slit. 8. Wheelchair lift according to claim 7, c h a r a c t e r i z e d in that the freewheel hub (9.3) is kept in a neutral position by means of a spring- loaded locking device (15) that is connected with the housing (14) .

Inventors: ERLANDSSON LARS, ERLANDSSON, LARS
Applicants: ERLANDSSON LARS, ERLANDSSON, LARS
Application year: 1998
Main classification: B66B9
IPC codes: B66B9