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(11) | EP 0 394 201 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A device for the ascent and descent of stairs for the disabled |
| (57) The present invention refers to a device for the ascent and descent of staircases
for the disabled. The device comprises a lifting structure, equipped with a standing or seating platform which is maintained in a constantly horizontal position, and is also equipped with a pair of rolling elements (3) and (4) which couple with tracks (1) and (2) by means of a cogged fit; each rolling element is accompanied by a bogie (5) and (6) which rotates around the same axle as the rolling element and which runs along the bottom edge of the tracks in such a way as to ensure the stability of the lifting structure; for the greater stability of the lifting structure, rollers (15) are fitted, which move along auxiliary tracks (16) which are mounted along certain tracts of the track; for the same reason pawls (18) are fitted, which prevent oscillation of the bogie along horizontal tracts, and thus prevent unwanted oscillation of the lifting structure under any circumstances. The device is equipped with an on-board motor and is able to move the lifting structure along tracts of variable gradient and around very narrow bends. |
[0001] The present invention concerns a device for the ascent and descent of stairs for the disabled.
[0002] Devices of the type in question are generally equipped with a lifting structure which moves along a system of tracks ranged along staircase ramps in such a way as to allow disabled persons, that is those not able to ascend and descend stairs autonomously, to overcome this obstacle. The lifting structure is usually equipped with a platform on which a wheelchair, or similar, or a seat, can be placed and on which the disabled person can sit. The platform must at all times be kept perfectly horizontal and must be particularly stable, that is it must not oscillate during its movement in such a way as to create difficulties for the person transported.
[0003] These requirements, together with the fact that the lifting structure must often move up and down ramps which are curvy and of varying gradient, create notable complications from the point of view of construction. For the movement of the lifting structure, fixed motors are normally used, which draw the structure by means of drawing systems which thus cause the structure to run along guiding tracks. As a rule this solution is complex from a constructional point of view, for which reason in the present invention an on-board motor is installed, even though this also creates some constructional problems.
[0004] On-board motorization, in fact, generally leads to the need for a system of guiding tracks as well as rack devices or similar, whose construction and assembly are usually quite complex, in particular when variations in gradient have to be dealt with.
[0005] The aim of the present invention is to provide a device for the ascent and descent of staircases for the disabled, which is equipped with an on-board motor, which can overcome tracts with variable gradient and with very sharp bends, and which nevertheless is simple in construction and assembly with regard to construction and assembly of the guiding and drawing system.
[0006] Further aim of the present invention is to provide a device which ensures great lifting structure stability, thus preventing any unwanted oscillation.
[0007] These aims and others besides are achieved by the present device as it is described in the appended claims.
[0008] Further characteristics and advantages of the invention will be better described during the detailed description which follows, of a preferred but not exclusive form of the present device, which is illustrated in the attached diagrams purely in the form of an example and is therefore not to be considered as unique:
- fig. 1 shows the vertical elevation section of the tracks and the rolling element group for the drawing along the tracks of the lifting structure;
- fig. 2 shows a schematic side-view of the lifting structure moving along the tracks;
- figs. 3 and 4 show, schematically and in enlarged scale, and pawl hold-down device, respectively in frontal view and in section.
- fig. 5 shows a schematic side-view of particulars of the braking system, with some parts removed for the better viewing of others;
- figs. 6 and 7 show, in front and side views respectively, details relative to the support elements of the tracks.
[0009] The device is question comprises a lifting structure equipped with a standing or seating platform on which the disabled person can stand or sit; this platform must always be kept in a horizontal position in order to avoid unwanted movements. The lifting structure moves along a system of tracks which are ranged along the staircase ramp. The track system comprises two tracks, respectively an upper track (1) and a lower track (2), which are realized by means of uniform oval-section tubular strips which are ranged along the length of the staircase ramp and which maintain exactly the same reciprocal distance, measured vertically, between their upper edges. The tracks are positioned one above the other in such a way that the major axes of their sections are exactly in line on a plane of symmetry of the tracks.
[0010] The lifting structure is supported by the tracks, and moves along them by means of a support and draw group which comprises a pair of rolling elements, respectively an upper element (3) and a lower element (4), which roll around fixed axles with respect to the lifting structure and which roll each on their respective track; the upper element (3) is driven by means of a motor, not illustrated in the diagram, which is on board the lifting structure. The motor is equipped with a pinion and transmission is achieved by means of a crown wheel (25) and a shaft (26) on which both the crown wheel and the rolling element are fixed. The lower element (4) rolls on a non-motorized shaft (27) on the end of which is a braking mechanism which will be better described below.
[0011] The rolling elements (3) and (4) roll on the tracks (1) and (2) by means by cogged fits which comprise a number of equidistant holes (9), bored into the surface of the tracks; each rolling element is fitted with pins (10), which extend radially and which are shaped and distanced in such a way as to fit each into one of the holes in the tracks as the rolling element proceeds. In this way, when the motor is started and the rolling element (3) rotates, the support and drawing structure move along the tracks, bringing with it the lifting structure.
[0012] The type of cogged fit described above has the particular advantage that the holes in the tracks (9) can be bored in situ after the tracks have been correctly positioned along the staircase ramps. This avoids the problem of having racks or similar which would have to made in the workshop and which could present assembly and positioning problems, especially in the case of long and curvy tracts. slightly superior to the major diameter of the track.
[0013] Each bogie is fitted with two parallel rolls so that the lifting structure is coupled to each track at three points, which are: the rolling element; and the two rolls on the bogie. In this way, lifting structure oscillations are prevented. This is especially true for tracts which have a gradient superior to about 15 degrees ; in such cases the frame on which the bogie is mounted rolls around its hinge axle as shown in fig. 2, thus constituting a secure anchor for the lifting structure.
[0014] Along horizontal tracts or tracts where the gradient is modest, such as for example in tracts with gradient variations ranging from horizontal to sloped tracts, oscillations of the lifting structure are possible.In order to avoid this eventuality, a second, smaller bogie, here termed a trolley (15), is fitted to the frame, laterally with regard to the larger bogie (5); where the gradient is modest, such as in fig. 2, an auxiliary track (16) is welded to the main track (1) and the trolley runs along this, thus constituting a further restriction for the lifting structure and preventing oscillation. As for horizontal tracts, a pawl (18) is fitted in correspondence with the tracks, which is operated by a cam (not illustrated in the diagram), and which fits into a hole (17) bored into the lifting structure, thus preventing frame oscillation. The trolley (15) and the pawl (18) prevent oscillation around a horizontal axle. To prevent oscillation around a vertical axle, a further bogie pair, here termed a dolly (19) is fitted on to the upper track group, and interacts with cams specially positioned in the curves of the tracks to stabilize the whole system; in cases where these dolly-wheels are cone-shaped, they can interact directly with the track. To cope with straight tracts, a second only (19a) is fitted which interacts internally with the track (2). Both the first and second dollies roll around axles mounted respectively on frame (7) and frame (8).
[0015] To prevent the rolling elements from slipping out sideways from the tracks, each rolling element is fitted with a lateral abutment, respectively (11) and (12), forming a throat out of which the pins (10) emerge perpendicularly; on the opposite sides contrast pulleys are fitted, respectively (13) and (14), mounted in such a way as to make contact with the tracks, thus constituting a further safeguard against the rolling elements' falling out sideways from the tracks.
[0016] The invention in question comprises also a braking device, fitting at one end of the shaft (27) on which the lower rolling element (4) is mounted. This braking device comprises a disk pair (31) and (32), which are fixed on the shaft (27) and rotate with it. The position of these disks forms a throat, inside which a hexagonal cam (33) and a cogwheel (34), attached to each other, are fitted. The group constituted by the cam (33) and the cogwheel (34) is set in motion by means of clutch disks (35) which act on the internal side surface of disks (31) and (32) and on the external side surfaces of the cogwheel (34). By means of a scoop spring (36), compressed by a ferrule, the disks (31) and (32) can be locked more or less tightly and in this way the degree of clutch developed between the disks and the internal cogwheel can be increased or decreased.
[0017] An anchor (37) is fitted, one of whose ends, round-shaped, interests the cam (33) while the other end, tooth-shaped, can interest the cogwheel (34). Through force of gravity, or by means of a spring, the anchor (37) tends to rest in the position with the round end falling on the cam (33). The cam is of such dimensions that when the round end falls on the sides of the hexagon the toothed end does not contact the teeth of the cogwheel (34), while when the round end falls on the edges of the hexagon, the toothed end of the anchor acts upon the teeth of the cogwheel (34).
[0018] When shaft velocity (27) (and therefore the lifting structure speed) is low, the round end of the anchor reaches each edge of the cam (33) at the moment in which the toothed end of the anchor (37) meets a space in the cogwheel (34); as rotation continues, the round end of the anchor falls successively on one of the sides of the hexagonal cam and lifts the toothed end (37), thus permitting the free rotation of the cogwheel (34).
[0019] When shaft velocity increases, during the passage of the round end from one edge of the hexagonal cam (33) to another, there is not enough time for the rotation of the anchor (37), so the toothed end acts upon the cogwheel teeth (34) and prevents it from rotating. This in turn leads to the creation of a couple between the clutch (35) and the cogwheel (31) and (32), which slows down the shaft rotation (27) until it comes to a complete stop. By means of the calibration of a spring, or movement of a counterweight, it is possible to act upon anchor inertia (37) and thus vary the speed at which the braking mechanism will intervene.
[0020] For the mounting of the track system on the staircase ramp there are several support elements, each of which comprises a prismatic guide bracket, which is fixed low down on the stair ramp, and which forms the base of the support element. A first element (42) is slid into this guide bracket and fixed in the required position: its top end, equipped with at least two perpendicular studs (43) is positioned on one of the steps of the staircase. The studs (43), which are threaded and accompanied by nuts, are used to fix the bottom end of a post (44); grooves are bored into the post's base for reception of the studs, whose function is the correct adjusting of the distance of the post from the staircase. There is a similar groove at the top end of the post (44).
[0021] An arm (45), which is fixed to the two tracks (1) and (2) is positioned at the top end of the post. This arm, like the post, has a groove bored into it for adjustment purposes; each post can be bolted to its relative arm (45). The fact of the two grooves allows the position of the tracks with respect to the vertical post (44) to be regulated.
[0022] The conformation of the above-described support elements both avoids the necessity to bore holes into the steps of the staircase and provides an extremely simple way of regulating the position of the support element in the three spatial directions.
[0023] A low tension busway (51) runs along the entire length of the lower track, from which, by means of wiping-contact (52), current is obtained to drive the on-board motor of the lifting structure.
[0024] The invention is extremely simple to assemble; the entire lifting structure and the relative guiding and drawing system are constructed in the workshop. In situ, only the two tracks, with their relative support elements, are assembled; even the holes (9) in the tracks for the pins of the rolling elements can be bored in the workshop, although if required they can also be bored after the tracks have been mounted.
[0025] Once this operation has been completed the lifting structure group is mounted on the tracks and is ready to perform its ascent and descent operations.
[0026] By operating the lifting structure's on-board motor, the shaft (26) begins to rotate and with it the rolling element (3); thanks to the cogged fit between the rolling element and the track, the entire lifting structure group can move along the track.
[0027] During horizontal tracts, the frame (7) is held steady by the pawl (18); the frame (7) being thus held steady, plus the further steadying provided by the trolley (15) ensure the stability of the lifting structure. During tracts where the gradient is steep (more than 15 degrees) frame (7) and (8) are free to oscillate and slide around their axles as in fig. 2, providing by themselves the stability required for the lifting structure, whose platform, perpendicular between the central axes of the rolling elements (2) and (1), remains perfectly horizontal. During low-gradient tracts, such as when the structure is passing from a horizontal tract to an inclined tract, the stability of the lifting structure is ensured by the trolley (15), which acts upon its track (16). Stability around the vertical axle is guaranteed by the dolly groups (19).
1) A device for the ascent and descent of stairs for the disabled, comprising: a lifting
structure, including a standing or seating platform which is constantly maintained
in a horizontal position, which moves along a track system that runs along staircase
ramps; a motor to cause movement of the lifting structure along the track system.
The invention is characterized by the fact that: the track system comprises two constant
section tracks (1) and (2) which maintain the same vertical distance between them,
measured between their upper edges; it comprises a pair of rolling elements (3) and
(4), rolling around fixed axles on the lifting structure and rolling each on their
respective track, at least one by means of the above-mentioned motor, which is positioned
on-board the lifting structure; relative to each rolling element a bogie (5) and (6)
is fitted, mounted on a frame (7) and (8) hinged to the rolling element's rotation
axle, which rolls on the track in question in a diametrically opposite position with
respect to the rolling element; at least between the motorized rolling element and
its relative track a cogged fit is foreseen.
2) A device as in claim 1, where said cogged coupling comprises: equidistant holes
(9) bored into the upper surface of the track on which the rolling element rolls;
pins (10) which emerge perpendicularly from the rolling element and which are positioned
in such a way as to fit successively each into one of the holes in the track as the
rolling element rolls.
3) A device as in claim 1, comprising a cogged fit between the rolling element and
the tracks.
4) A device as in claims 1 and 2, characterized in that: said tracks are made of oval-section
tubular strips and are disposed so that the major axes of their sections are exactly
one above the other on a plane of symmetry containing the axes of said holes; each
rolling element comprises one molded wheel with a lateral abutment (11) and (12) forming
a throat out of which said pins emerge perpendicularly; relative to each rolling element
there is a contrast pulley (13) and (14) placed in contact with the track and opposite
the lateral abutment of the rolling element; in correspondence with at least one of
the rolling element groups a trolley (15) is fitted, mounted on the lifting structure,
which is disposed laterally to said trolley and which interacts with tracts of auxiliary
tracks (16) attached to the relative track where the tract gradient is less than about
15 degrees; a block hole (17) is bored into the lifting structure in correspondence
with at least one of the rolling elements, which can receive a pawl (18), formed and
disposed in such a way as to prevent oscillation of the frame when inserted into the
block hole; said insertion (and relative extraction) is attained by means of a system
of cams positioned in correspondence with horizontal tracts of the tracks.
5) A device as in claims 1 and 3, comprising a braking device, calibrated on a shaft
(27) which interests one of the rolling elements and which is idle with respect to
its own rotation axle, which in turn comprises: a disk pair (31) and (32) in fixed
rotation with said shaft, forming between them a throat; a hexagonal cam (33) and
a cogwheel (34), fixed together and coaxial, which are positioned inside said throat;
a number of friction disks (35) interplaced between the inside lateral surfaces of
the disk pair and the outside lateral surfaces of the cogwheel; an anchor (37), one
end of which is round-shaped and acts on said cam, the other end of which is tooth-shaped
and acts on the teeth of the cogwheel; said anchor rotates around a fixed axle with
respect to said shaft axle, and since it is formed in such a way that when the round
end falls on the sides of the hexagonal cam the toothed end does not interfere with
the cogwheel teeth while when the round end falls on the edges of said hexagonal cam
the toothed end acts on the teeth of the cogwheel.
6) A device as in claim 1, comprising a number of support elements for the tracks,
each of which comprises: a prismatic bracket (41), which is fixed to the lower part
of the staircase ramp; a first element (42), one of whose ends is inserted into the
prismatic bracket, and whose other end rests on one of the steps of the staircase,
comprising at least two studs (43) which point upwards in a vertical direction; a
post (44), whose lower end is positioned on the upper end of the first element and
has grooves which said studs fit into, whose upper, vertical end has a further groove;
an arm, fixed to the tracks, which also has a groove for fitting to and adjustment
with said post.