A RAILSYSTEM FOR A CHAIR LIFT OR THE LIKE, WHICH IS MOUNTED ON OR ALONG A FLIGHT OF STAIRS

Description

[0001] The invention relates to a rail system for a chair lift or the like, said system being mountable on or along a staircase and comprising a rail having inclined guide surfaces and composed of a rail portion to be mounted in a fixed position and an end portion being able to swivel, relatively to a lower end of said rail portion, between a position wherein the guide surfaces of said end portion are aligned with the guide surfaces of said rail portion and a position wherein a free passageway across in front of the staircase is less blocked by said end portion.

[0002] Such rail systems, sold and installed before January 10, 1989 by De Reus B.V., are provided with an end portion which can be swung from the aligned position to the left or the to right to minimize obstruction by the rail at the bottom of the staircase. To be able to guide a chair lift to the level of the floor before the staircase, the rail has to exend some distance beyond the end of the staircase. If the staircase, as is often the case, terminates in a hall or corridor extending transversely to the staircase, then the rail portion extending beyond the end of the staircase forms an inconvenient obstacle. By constructing the projecting rail portion as a swing-aside end portion, the hindrance encountered can be reduced.

[0003] In the design of such a swivelling construction, a number of points have to be taken into account. The rail has a guiding function, which should not be disturbed. This implies that the guide surfaces should remain free from hinge projections and hinge attachment portions. Furthermore, it will be necessary that forces and moments are transmitted between the fixed rail portion and the end portion without this having any material effect on the smooth transition from the rail portion to the end portion. In known rail systems of the above described type, for that purpose the end portions are constructed designed to be swivelled to the left or to the right with respect to the fixedly mounted rail portion. The hinge shaft then extending substantially vertically presents a good starting point for the guide surface transition and the transmission of forces to take place in the desired manner.

[0004] However, the swinging or swivelling to the left or to the right of the end portion can also be very annoying. Depending on whether the rail system is mounted on the left or on the right hand side of the staircase, swivelling to the right or to the left of the end portion means that this impedes or even prevents the normal use of the stairs. Such an arrangement will preferably not be chosen but will be necessary in certain cases, e.g. because swivelling away from the staircase is precluded by a wall or a door.

[0005] It is an object of the present invention to construct the end portion in such a manner that in the swung-aside or swivelled-aside position, it hardly impedes the normal use of the staircase and the swivelling or swinging movement cannot be obstructed by doors or walls which may be present, and so that a proper transmission of forces and a smooth guide surface transition is preserved.

[0006] The objects set are achieved, according to the present invention, because of the fact, that the end portion is adapted to swivel from said aligned position upwards and backwards in the direction of said rail portion into a vertical above the staircase withdrawn, against the lower end of said rail portion abutting position. These features allow the end portion to be placed with a tilting/swivelling movement upright against the fixed rail portion. No obstructions are expected in that direction, as this is the space through which the lift chair has to move for reaching the floor level before the staircase. Furthermore, the tilting/swivelling movement effects that when the end portion swivels downwards, this can come into abutment against the fixed end portion, whereby the desired transmission of forces and smooth guide surface transition can be realized.

[0007] An additional advantage of the features according to the present invention is that the construction has become more universal, i.e. swivelling movements to the one or to the other side need not be taken into account, as is the case in the prior art, and moreover like structural members can be used, no matter whether the rail system is mounted on the left or on the right hand side of the staircase. This makes for cheaper and simpler manufacture and storage of parts.

[0008] The tilting/swivelling movement can be realized in a relatively simple manner when, in accordance with a further embodiment of the present invention, in the position in which the guide surfaces of the end portion are in alignment with those of said rail portion, said end portion is provided at a point spaced from the lower end of said fixed portion with at least one hinge shaft to which, through control and displacement means, is imparted a movement which brings the end portion in the vertical above the staircase withdrawn position. The end of the fixed rail portion can then serve as a second bearing or supporting surface for the end portion. Preferably however, there are provided two hinge shafts spaced apart longitudinally of the end portion, to at least one of which hinge shafts the desired movement can be imparted by the control and displacement means. It can thus be ensured in a simple manner that the end portion is displaced in an accurately controlled manner throughout its entire movement.

[0009] One or both hinge shafts nay consist of pins or journals guided in a cam track groove. However, it is preferred that the hinge shafts are each connected to the end of a swivel lever and the other ends of said swivel levers are connected through hinge shafts to two spaced fixed points and at least one of the swivel levers forms part of the control and displacement means. Thus the up-and-down swivelling movement of the end portion can be realized in a simple manner by rotationally driving one of the hinge shafts on the other ends of the swivel levers, e.g. through an electric motor, which can be energized from the staircase ends or from the chair lift. Naturally the up-and-down swivelling motion of the end portion may be effected manually, or manually or with a motor at the user's choice.

[0010] According to a further preferred embodiment of the present invention, one of the hinge shafts is provided near the lower end of the end portion and the swivel lever coacting with the other hinge shaft on the end portion is drivable rotationally by a motor at its articulation with the fixed points. The drive unit can then be arranged on the staircase and substantially underneath the fixed rail portion, while the end portion, in its swung-down or swivelled-down position, can be supported optimally at its two ends. It is further preferred that, for effecting the tilting/swivelling motion of the end portion from the inclined position to the substantially vertical position and vice versa, the swivel lever coacting with the hinge shaft provided near the lower end of the end portion extends substantially horizontally when the end portion is in the position in alignment with said rail portion and the swivel lever coacting with the other hinge shaft in that position of the end portion encloses an acuter angle therewith than the swivel lever coacting with the hinge shaft disposed near the lower end of the end portion, and in its other extreme position said swivel lever extends substantially vertically. Owing to these features in both extreme positions the end portion can be moved into a stable horizontal or vertical position that is maintained by gravity, while the other lever, which is not parallel to the subjacent lever, provides for the tilting movement during swivelling.

[0011] The stabilization of the swivel lever connected to the lower end of the end portion can be maximized when, according to a still further embodiment of the present invention, the hinge shaft at the lower end of the end portion is coplanar with the hinge shafts of the other swivel lever when the end portion is in the position in alignment with said rail portion. Thus the swivel lever connected to the lower end of the end portion cannot swivel further downwards and the lowermost position of the end portion is accurately defined.

[0012] When, according to a still further embodiment of the present invention, there is provided a spring which stabilizes the end portion in at least one of its end positions, and also promotes at least the end portion's swivelling upwards and in the direction of said rail portion, there is obtained a construction by means of which both the retention in both end positions can be promoted, and the tilting/swivelling motion can be balanced. One possibility is e.g. a spring attached at its one end to the swivel lever coacting with the hinge shaft provided near the lower end of the end portion, i.e. about half-way the two hinge shafts at the ends of said lever, with the other end of the spring connected to the other lever near its hinge shaft connected to the fixed point. Thus a construction can be realized wherein the spring pulls the end portion into its two end positions, while after the end portion's being moved out of its swung-down end position, the spring supports the upwardly swivelling movement of the end portion and damps its downward movement, which, too, has its advantages if a hand-operated embodiment is chosen.

[0013] In accordance with still another preferred embodiment of the present invention, in the position wherein the end portion and the rail portion are in alignment with one another, the boundary face between the two extends substantially vertically. Owing to the inclined position of the rail, the substantially vertical boundary face means that the end portion is supported on the fixed rail portion, which optimizes the transmission of forces. Likewise, a tilting/swivelling displacement can then be initiated and terminated without any problem, while in the swung-up or swivelled-up position, the then substantially vertical end portion can rest against a likewise vertical supporting surface. Besides, it may further be arranged for the end portion to be lockable in its two extreme positions, which locking can be realized practically automatically as a result of the tilting/swivelling displacement of the end portion towards the end of said displacement, e.g. by using hook-shaped webs.

[0014] One embodiment of the rail system according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a top view of a chair lift with rail system according to the invention, wherein rail system portions located underneath the chair lift are shown in solid lines;

Fig. 2 is a front view of Fig. 1, wherein again rails system portions now located behind the chair lift, more in particular of the swing-up or swivel-up end portion, are shown in solid lines;

Fig. 3 is a top view of the rail system with the end portion in swung-up or swivelled-up position; and

Fig. 4 is a front view of Fig. 3.

[0015] Figs. 1 and 2 diagrammatically show a chair lift 1 movable along a rail system 2. The manner of guiding and driving chair lift 1 is not further shown and will not be discussed, as this is not relevant to the subject matter of the present invention.

[0016] The rail system 2 comprises a rail portion 5 connected fixedly to a wall 3 and/or a staircase 4, said rail portion 5 linking up with a swing-up or swivel-up end portion 6 shown in Figs. 1 and 2 in its swung-down or swivelled-down end position, where end portion 6 is in alignment with the fixed rail portion 5. End portion 6 extends substantially down to a floor 7 before staircase 4, so that a user of chair lift 1 can step out of the chair without any problem.

[0017] As best shown in Fig. 1, in the swung-down position of end portion 6, a door 8 cannot be opened when this swivels in the manner shown in Fig. 3, which swivelling direction is conventional when door 8 is a front door. If end portion 6 swivels away about a vertical shaft in the direction of door 8, this offers no solution in the present case, because no sufficient room is available for the purpose. In situations in which there is sufficient room though, mostly a door is present beside the staircase 4, leading to another room, such as a toilet or a storage or meter cupboard or the like. Swivelling away in the other direction brings the end portion 6 in transverse position before staircase 4 and obstructs its normal use. According to the present invention, it is therefore proposed to swivel end portion 6 backwards and upwards, as shown in Figs. 3 and 4.

[0018] To that end, end portion 6 is hingedly connected to both a swivel lever 9 and to a swivel lever 10, each composed of two lever arms arranged on either side of the rail. One end of swivel lever 9 is coupled through a hinge shaft 11 with the lower end of the end portion 6, and the other end of swivel lever 9 is connected through a hinge shaft 12 to a supporting construction 13 fixedly connected to staircase 4. Swivel lever 10 is coupled at one end through a hinge shaft 14 to supporting construction 13 and at its other end through a hinge shaft 15 to end portion 6. In order not to influence the guide surfaces of end portion 6, hinge shafts 11 and 15 are not mounted directly in end portion 6 but in portions 16, 17 fixedly connected thereto. The relative positions of the hinge shafts are so chosen that in the swung-down position of end portion 6, as shown in Fig. 2, hinge shafts 11, 14 and 15 are substantially aligned, which implies that swivel lever 9 cannot swivel further downwards than the position shown in Fig. 2, or that a highly stable lift guiding and supporting position for end portion 6 is realized.

[0019] This stable position is further promoted by giving boundary face 18, between fixed rail portion 5 and end portion 6, a substantially vertical position, so that end portion 6, when being loaded by lift chair 1, at the location of boundary face 18, is supported against fixed rail portion 5. It is observed that boundary face 18 continues into portion 17 connected fixedly to end portion 6 and fixed rail portion 5.

[0020] A motor 19 is provided for swivelling end portion 6 upwards from the position shown in Fig. 2 into the position shown in Fig. 4, or vice versa, which motor 19 is adapted to rotate hinge shaft 14. The activation of motor 19 can be arranged in such manner that this is controllable from the staircase ends or from the chair lift 1.

[0021] The swung-up or swivelled-up position of end portion 6 is shown in Figs. 3 and 4. As clearly shown in Fig. 3, the door 8 in this position can swing open unimpededly, while the normal use of staircase 4 is practically not hindered. It will also be clear that in the presence of a door beside the staircase, this door is not blocked by end portion 6 in its swung-up position.

[0022] In the position shown in Fig. 4, end portion 6 rests against the lower end of the fixed rail portion 5, which provides a stable location. As the end portion, during its displacement, executes both a swivelling and a tilting movement, a lock can be realized, i.e. through this movement, in a relatively simple manner by means of hook-shaped webs, not shown, on the end portion and a fixed portion, which webs, at the end of the tilting/swivelling motion, automatically come into contact with one another. Such a lock can naturally also be realized in the swung-down or swivelled-down position.

[0023] In the embodiment shown, the rail system - as viewed in upward direction of staircase 4 - is provided on the left thereof. It will be clear from the drawings, and in particular from the top views, that the rail system 2 could just as well have been disposed on the right of staircase 4; only the motor 19 should then have been placed on the other side, which is possible by simple constructive means.

[0024] The stabilization in the two end positions can be improved by stretching a diagrammatically shown extension spring 21 between an attachment point 22 on swivel lever 10 near hinge shaft 14 and an attachment point 23 on swivel lever 9. In the swung-down position shown in Fig. 2, spring 21 has no influence due to the alignment of shafts 11, 14 and 15 and the fact that spring 21 has been displaced past its furthest extended position. When spring 21 is brought out of that position, it is extended slightly further, after which it will contract, thereby supporting the swing-up motion. In the swung-up end position, shown in Fig. 4, spring 21 is in its most contracted position, so that this swung-up position is stable as well. Furthermore, during the downward movement of end portion 6, spring 21 damps the swivelling motion reinforced through gravity. Thus extension spring 21 stabilizes end portion 6 in its two end position and its movement balances during the displacement between the two end positions, which is advantageous both in the case of hand and motor operation.

[0025] A motor-operated embodiment has been described hereinbefore. The end portion 6, instead of by a motor, can also be brought into its swung-up position manually, the more so as with a lift as the present one, in the event of breakdown, e.g. a mains supply failure, a safety mechanism is actuated which arrests the lift, after which the lift can be further displaced manually along its guide. The end portion 6 should then be brought manually into its swung-down or swivelled-down position. With manual operation, the end portion can be gripped directly to prevent the hand from being fouled, e.g. with a lubricant, a hand grip or handle may be provided, e.g. on portion 17 in the vicinity of the boundary face between the fixed rail portion 5 and end portion 6.

[0026] It is observed that many modifications and variants are conceivable within the scope of the appended claims. For instance, the fulcrum 12 can be placed on the first step of the staircase 4, so that the swung-up end portion can be brought entirely within the bounding plane of the staircase, i.e. - as viewed in Fig. 3 - to the right behind the line 20. During the swivelling/tilting motion, hinge shafts 11 and 15 describe a given path. Instead of by swivel levers 9 and 10, these paths, or one of them, can be defined by sliding or rotating the hinge shafts, or one of them, in a guide groove. As end portion 6, in the position shown in Fig. 2, can bear against the fixed rail portion 5, one swivel lever would in principle suffice be it that in such case a lock should always be provided near the boundary face 18 if a guide support of the chair lift 1 can move beyond the hinge shaft on the end portion. For stability considerations, consequently, at least a double engagement with end portion 6 is preferred. Instead of extension spring 21, a torsion spring or a gas spring may be provided for promoting the stability in the end positions and facilitating the tilting/swivelling displacement.

Claims

1. A rail system (2) for a chair lift (1) or the like, said system (2) being mountable on or along a staircase (4) and comprising a rail (5, 6) having inclined guide surfaces and composed of a rail portion (5) to be mounted in a fixed position and an end portion (6) being able to swivel, relatively to a lower end of said rail portion (5), between a position wherein the guide surfaces of said end portion (6) are aligned with the guide surfaces of said rail portion (5) and a position wherein a free passageway across in front of the staircase (4) is less blocked by said end portion (6), characterized in that the end portion (6) is adapted to swivel from said aligned position upwards and backwards in the direction of said rail portion (5) into a vertical above the staircase (4) withdrawn, against the lower end of said rail portion (5) abutting position.

2. A rail system as claimed in claim 1, characterized in that the end portion (6), in the position in which its guide surfaces are in alignment with those of said rail portion (5), at a point spaced apart from the lower end of said rail portion (5), is provided with at least one hinge shaft (11; 15) to which, through control and displacement means (10, 14, 19), can be imparted a movement that brings the end portion (6) in the vertical above the staircase (4) withdrawn position.

3. A rail system as claimed in claim 2, characterized in that there are provided two hinge shafts (11,15) spaced apart longitudinally of the end portion (6), to at least one of which the desired movement can be imparted by the control and displacement means (10,14,19).

4. A rail system as claimed in claim 3, characterized in that the hinge shafts (11,15) are each connected to the end of a swivel lever (9,10) and the other ends of said swivel levers are connected through hinge shafts (12,14) to two spaced fixed points and at least one of the swivel levers (10) forms part of the control and displacement means (10,14,19).

5. A rail system as claimed in claim 4, characterized in that one of the hinge shafts (12) is provided near the lower end of the end portion (6) and the swivel lever (10) coacting with the other hinge shaft (15) on the end portion (6) is drivable rotationally by a motor (19) at its articulation with the fixed points.

6. A rail system as claimed in claim 5, characterized in that the swivel lever (9) coacting with the hinge shaft (11) disposed near the lower end of the end portion (6) extends substantially horizontally when the end portion (6) is in the position in alignment with said rail portion (5) and the swivel lever (10) coacting with the other hinge shaft (15) in that position of the end portion (6), encloses an acuter angle therewith than the swivel lever (9) coacting with the hinge shaft (11) disposed near the lower end of the end portion (6), and in its other extreme position said swivel lever (9) extends substantially vertically.

7. A rail system as claimed in claim 6, characterized in that the hinge shaft (11) at the lower end of the end portion (6) is coplanar with the hinge shafts (14,15) of the other swivel lever (10) when the end portion (6) is in the position in alignment with said rail portion (6).

8. A rail system as claimed in any of the preceding claims, characterized in that there is provided a spring (21) which stabilizes the end portion (6) in at least one of its end positions, and also promotes at least the swivelling of the end portion (6) in upward direction and in the direction of said rail portion (5).

9. A rail system as claimed in claim 7 and 8, characterized in that the spring (21) is attached at its one end to the swivel lever (9) coacting with the hinge shaft (11) provided near the lower end of the end portion (6), i.e. about half-way the two hinge shafts (11;12) at the ends of said lever (9), with the other end of the sprang (21) connected to the other lever (10) near its hinge shaft (14) connected to the fixed point.

10. A rail system as claimed in any of the preceding claims, characterized in that in the position wherein the end portion (6) and the rail portion (5) are in alignment with one another, the boundary face (18) between the two extends substantially vertically.

11. A rail system as claimed in any of the preceding claims, characterized in that in the two extreme positions the end portion (6) is in a stable position maintained through gravity.

12. A rail system as claimed in any of the preceding claims, characterized in that the end portion (6) is lockable in its two extreme positions.

Ansprüche

1. Schienensystem (2) für einen Stuhllift (11) oder dergleichen, der auf oder entlang einem Stuhlträger (4) angeordnet ist, wobei eine Schiene (5, 6) mit abgewinkelten Führungsflächen und einem Schienenabschnitt (5) in einer festen Stellung relativ zu einem unteren Endabschnitt des Schienenabschnittes (5) verschwenkbar ist, zwischen einer Stellung, in welcher die Führungsflächen des genannten Endabschnittes eine Ausrichtung auf die Führungsflächen des genannten Schienenabschnittes (5) erfahren, in welcher Stellung ein unbehinderter Eintritt bei der Vorderseite des Stuhlträgers (4) besteht, in welcher Stellung der Stuhlträger (4) mittels des genannten Endabschnittes (6) weniger blockiert ist,
dadurch gekennzeichnet,
daß der Endabschnitt (6) für eine Verschwenkbewegung aus der genannten, ausgerichteten Stellung aufwärts und nach hinten mit
   der Richtung des Schienenabschnittes (5) in eine Horizontale oberhalb des Stuhlträgers (4) zurückgezogen wird, wohingegen die unteren Endabschnitte der genannten Schienenabschnitte (5) in ihre Anschlaglage gelangen.

2. Schienensystem nach Anspruch 1,
dadurch gekennzeichnet,
   daß der Endabschnitt (6) in der Stellung, in welcher seine Führungsflächen mit denjenigen des Schienenabschnittes (5) sich in einer Stellung befinden, die vom unteren Ende des genannten Schienenabschnittes (5) an einer Stelle beabstandet sind, die mittels wenigstens einer Gelenkwelle (11, 15), an welcher sich eine Regelung und eine Verschiebeeinrichtung befindet, zu einer Bewegung führen, bei der der Endabschnitt (6) in die Vertikale oberhalb des Stuhlträgers (4) in ihrer zurückgezogenen Stellung stehen.

3. Schienensystem nach Anspruch 2,
dadurch gekennzeichnet,
   daß zwei Gelenkwellen (11, 15) in Längsrichtung zum Endabschnitt (6) voneinander beabstandet sind, daß wenigstens eine von ihnen die gewünschte Bewegung vom Regler mit den Verschiebungsmitteln (10, 14, 19) überträgt.

4. Schienensystem nach Anspruch 3,
dadurch gekennzeichnet,
   daß die Gelenkwellen (11, 15) jeweils am Ende eines Schwenkhebels (9, 10) angeordnet sind, deren anderes Ende über Gelenkwellen (11, 15) und die anderen Ende der Schwenkhebel über Gelenkwellen (12, 14) an zwei beabstandeten, ortsfesten Punkten und Wenigstens einer der Schwenkhebel (10) einen Teil der Regler und Verschiebungsmittel bilden. (10, 14, 19)

5. Schienensystem nach Anspruch 4,
dadurch gekennzeichnet,
   daß eine der Gelenkwellen (12) mit einem unteren Ende des Endabschnittes (6) und der Schwenkhebel (10) mit der anderen Gelenkwelle (15) zusammenwirkt, während die andere Gelenkwelle (15) an ihrem unteren Endabschnitt (6) einen Drehantrieb eines Motors (19) an ihren Gliederaufbau mit den festen Stellen aufweist.

6. Schienensystem nach Anspruch 5,
dadurch gekennzeichnet,
   daß der Schwenkhebel (9) mit der Gelenkwelle (11) in Nähe des unteren Endes des Endabschnittes (6) sich im wesentlichen horizontal erstreckt, während der Endabschnitt (6) seine Ausrichtstellung in Bezug auf den Schienenabschnitt (5) einnimmt, und der Schwenkhebel (10) mit der anderen Gelenkwelle (15) in dem Abschnitt der beiden Endabschnitte (6) angeordnet ist, wobei er ein spitzwinkliges Dreieck damit bildet, wenn der Schwenkhebel (9), der mit der Gelenkwelle (11) des unteren Endes des Endabschnittes (6) zusammenwirkt, und sich in seiner anderen Endstellung befindet, und der Schwenkhebel (9) sich im wesentlichen vertikal erstreckt.

7. Schienensystem nach Anspruch 6,
dadurch gekennzeichnet,
   daß die Gelenke (11) am unteren Ende des Endabschnittes (6) coplanal in Bezug auf die Gelenkwellen (14, 15) des anderen Schwenkhebels (10) ausgebildet sind, und der Endabschnitt (6) seine Ausrichtstellung in Bezug auf den Endabschnitt (6) einnimmt.

8. Schienensystem nach einen der vorhergehenden Ansprüche,
dadurch gekennzeichnet,
   daß eine Feder (21) vorgesehen ist, die wenigstens in einer ihrer Endstellungen die Endabschnitte (6) stabilisiert und weiterhin die Verschwenkung des Endabschnittes (6) in Aufwärtsrichtung und in Richtung des Schienenabschnittes (5) fördert.

9. Schienensystem nach den Ansprüchen 7 und 8,
dadurch gekennzeichnet,
   daß die Feder (21) endseitig mit dem Schwenkhebel (9) verbunden ist, der mit der Gelenkwelle (11) in Nähe des unteren Endes der Endabschnitte (6) besteht, mit anderen Worten auf halber Strecke der Gelenkwellen (11, 12) an den jeweiligen Enden der Hebel (9), wohingegen das andere Ende der Feder (21) in Verbindung mit dem anderen Hebel (10) in Nähe der Gelenkwelle (14), die mit dem festen Punkt verbunden ist, steht.

10. Schienensystem nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet,
   daß der Endabschnitt (6) und der Schienenabschnitt (5) in Bezug zueinander ausgerichtet sind, wobei die Grenzflächen (18) zwischen zwei Endwerten im wesentlichen vertikal verlaufen.

11. Schienensystem nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet,
   daß in den zwei Endstellungen der Endabschnitte (6) diese in stabiler Lage auf Grund ihrer Schwerkraft gehalten sind.

12. Schienensystem nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet,
   daß die Endabschnitte (6) in ihren beiden Extremstellungen verriegelt sind.

Revendications

1. Un système de rail (2) pour un monte-chaise (1) ou analogue, ledit système (2) pouvant être monté sur ou le long d'un escalier (4) et comprenant un rail (5, 6) ayant des surfaces de guidage inclinées et composé d'une portion de rail (5) à monter à une position fixe et une portion d'extrémité (6) propre à pivoter, relativement à une extrémité inférieure de ladite portion de rail (5), entre une position où les surfaces de guidage de ladite portion d'extrémité (6) sont alignées avec les surfaces de guidage de ladite portion de rail (5) et une position où un chemin de passage libre en travers et en regard de l'escalier (4) est moins bloqué par ladite portion d'extrémité (6), caractérisé en ce que la portion d'extrémité (6) est adaptée pour pivoter de ladite position alignée vers le haut et vers l'arrière en direction de ladite portion de rail (5) à une position verticale en retrait au-dessus de l'escalier (4) butant contre l'extrémité inférieure de ladite portion de rail (5).

2. Un système de rail comme revendiqué dans la revendication 1, caractérisé en ce que la portion d'extrémité (6), à la position à laquelle ses surfaces de guidage sont en alignement avec celles de ladite portion de rail (5), est prévue, à un point espacé de l'extrémité inférieure de ladite portion de rail (5), avec au moins un axe d'articulation (11 ; 15) auquel peut être communiqué, à travers des moyens de commande et de déplacement (10, 14, 19), un déplacement qui amène la portion d'extrémité (6) à la position verticale en retrait au-dessus de l'escalier (4).

3. Un système de rail comme revendiqué dans la revendication 2, caractérisé en ce que sont prévus deux axes d'articulation (11, 15) espacés longitudinalement à la portion d'extrémité (6), à au moins l'un desquels le déplacement désiré peut être communiqué par les moyens de commande et de déplacement (10, 14, 19).

4. Un système de rail comme revendiqué dans la revendication 3, caractérisé en ce que les axes d'articulation (11, 15) sont chacun connectés à l'extrémité d'un levier à tourillon (9, 10) et les autres extrémités desdits leviers à tourillon sont reliées à travers des axes d'articulation (12, 14) à des points fixes espacés, et au moins l'un des leviers à tourillon (10) forme une partie des moyens de commande et déplacement (10, 14, 19).

5. Un système de rail comme revendiqué dans la revendication 4, caractérisé en ce que l'un des axes d'articulation (12) est prévu près de l'extrémité inférieure de la portion d'extrémité (6), et le levier à tourillon (10) coopérant avec l'autre axe d'articulation (15) de la portion d'extrémité (6) peut être entraîné en rotation par un moteur (19) à son articulation avec les points fixes.

6. Un système de rail comme revendiqué dans la revendication 5, caractérisé en ce que le levier à tourillon (9) coopérant avec l'axe d'articulation (11) disposé près de l'extrémité inférieure de la portion d'extrémité (6) s'étend sensiblement horizontalement lorsque la portion d'extrémité (6) est à la position en alignement avec ladite portion de rail (5) et le levier à tourillon (10) coopérant avec l'autre axe d'articulation (15) est à cette position de la portion d'extrémité (6), forme un angle avec celle-ci plus aigu que le levier à tourillon (9) coopérant avec l'axe d'articulation (11) disposé près de l'extrémité inférieure de la portion d'extrémité (6), et ledit levier à tourillon (9) s'étend sensiblement verticalement à son autre position extrême.

7. Un système de rail comme revendiqué dans la revendication 6, caractérisé en ce que l'axe d'articulation (11) à l'extrémité inférieure de la portion d'extrémité (6) est coplanaire avec les axes d'articulation (14, 15) de l'autre levier à tourillon (10) lorsque la portion d'extrémité (6) est à la position en alignement avec ladite portion de rail (6).

8. Un système de rail comme revendiqué dans l'une quelconque des revendications précédentes, caractérisé en ce qu'est prévu un ressort (21) qui stabilise la portion d'extrémité (6) dans au moins l'une de ses positions d'extrémité, et également contribue au moins au pivotement de la portion d'extrémité (6) en direction vers le haut et en direction de ladite portion de rail (5).

9. Un système de rail comme revendiqué dans les revendications 7 et 8, caractérisé en ce que le ressort (21) est lié par une de ses extrémités au levier à tourillon (9) coopérant avec l'axe d'articulation (11) prévu près de l'extrémité inférieure de la portion d'extrémité (6), c'est-à-dire à mi-distance des deux axes d'articulation (11, 12) aux extrémités dudit levier (9), l'autre extrémité du ressort (21) étant connectée à l'autre levier (10) près de son axe d'articulation (14) connecté au point fixe.

10. Un système de rail comme revendiqué dans l'une quelconque des revendications précédentes, caractérisé en ce qu'à la position où la portion d'extrémité (6) et la portion de rail (5) sont en alignement l'une avec l'autre, la face limite (18) entre les deux s'étend sensiblement verticalement.

11. Un système de rail comme revendiqué dans l'une quelconque des revendications précédentes, caractérisé en ce qu'aux deux positions extrêmes, la portion d'extrémité (6) est a une position stable maintenue par gravité.

12. Un système de rail comme revendiqué dans l'une quelconque des revendications précédentes, caractérisé en ce que la portion d'extrémité (6) est verrouillable à ses deux positions extrêmes.

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