Field of application of the invention

The present invention relates to elevators and, in particular, to a system for moving on single rail the telescopic doors of an elevator cabin and the floor doors.

Review of the known art

Presently known systems for moving the doors of an elevator cabin make use of operating means, typically a geared-down electric motor that controls a suitable kinematic mechanism connected to the doors. The horizontally sliding doors are fixed to respective carriages translating on one or two rails according to the configuration used. The configuration with only one rail for translating two carriages, to which two respective doors sliding in opposite directions are fixed, requires a larger sliding space at the two sides of the cabin, equal to the width of each door, to receive them when open. Halving the lateral bulk is achieved by using two rails for two carriages with two doors that slide in the same direction, one rail for each door. Such a conformation is known in technical jargon as "telescopic" because the movement is similar to that which occurs when the tubular elements of a telescope disappear inside each other. One door in fact moves twice the distance of the other so that, although both doors move in the same direction, when the slower one is fully inside the lateral seat in the open position, the same is true of the faster door that disappears leaving a free space for access to the cabin. The return movement of the doors in the opposite direction takes place when they close. Conformations are also known where there are four doors, the so-called 'four panel center opening doors' wherein a first pair of doors slides telescopically in one direction and a second pair of doors simultaneously slides, also telescopically, in the opposite direction. The same 'telescopic' or 'four panel center opening doors' configurations can be used on the doors for access and egress at the floors.

The drawback to these known systems of 'telescopic' or 'four panel center opening doors' is their greater crosswise bulk created by the double rail and its carriage.

Figure 1 exemplifies a known system for moving the two 'telescopic' doors 1 and 2. The doors are shown when access to the cabin is closed; the arrows indicate the. direction of aperture; the double arrow associated to door 1 means that it is the faster one (covering a distance double that of door 2 in the same time). Beside the slower door 2, an empty space 3 can be seen to receive the doors when they slide open. The upper side of the faster door 1 is joined to a main carriage 4 constrained to the two sides of a horizontal rail 5 that extends into the space 3. On the roof of the cabin, rail 5 is rigidly joined to the load- bearing frame of the cabin. Carriage 4 is constrained to the rail 5 by four wheels 6a, 6b and 7a, 7b. Wheels 6a and 6b roll along the upper edge of rail 5 and in so doing support the weight of door 1. Wheels 7a and 7b are counter- wheels in contact with the opposite edge of rail 5 to keep the load-bearing wheels 6a and 6b in their seat. Opposite rail 5 a second rail 11 , outwards in relation to the cabin, is also rigidly joined at roof level to the load-bearing frame of the cabin. To simplify the description, rail 11 is shown above rail 5 while in actual fact it is below. The carriage 8 slides along the rail 11 on four wheels 9a, 9b, and 10a, 10b. Wheels 9a and 9b roll along the upper edge of the rail and in so doing support the weight of the door 2. Wheels 10a and 10b, are counter-wheels in contact with the opposite edge of rail 8 to keep the load- bearing wheels 9a and 9b in their seat. Figure 2 shows the crosswise double-T profile of rail 5, identical to the crosswise profile of rail 11, with two longitudinal edges, 5a and 5b, at each side of the double T one at the top and one at the bottom.

Figure 3 shows a side view of the system in Figure 1. Figure 3 shows the rail 5 and the opposite rail 11, on which wheels 9a and 10a move perpendicular to the sheet. Rails 5 and 11 are connected to the load-bearing frame of the elevator cabin (or to the wall at floor level) on the outside of the cabin in proximity to the roof, by means of couples of fixing elements, 12 and 13, placed so as to avoid interference with the movement of carriages 4 and 8. Along the circumference of the load-bearing wheels and the counter- wheels, is a groove that couples with the T-shaped profile of the corresponding edge of the respective rail. Rotation takes place on ball bearings fixed by pins to the carriage. Figure 3 clearly shows the crosswise bulk of the telescopic doors. Summary of the invention

Purpose of the present invention is to overcome the drawback due to crosswise bulk of the telescopic doors moving along two distinct rails. Subject of the invention is therefore a system for moving the door of an elevator cabin, comprising:

a single rail horizontally joined to the external frame of the cabin or to the car sling;

at least two carriages to slide along the single rail for moving the two respective doors;

a motor-driven device fixed to the external frame of the cabin or to the car sling to control the sliding movement of the carriages both in the same direction with strokes of different lengths and therefore at a different speed, as described in claim 1.

Further characteristics of the present invention, considered innovative, are described in the dependent claims.

In the model with only two carriages, the door drawn by the faster carriage completes a translation equal to the width of the entire space for entry to the cabin, while the slower carriage is drawn by the faster carriage by means for transmission of the movement, halving the stroke and therefore the speed. According to the invention the rail consists of a longitudinal wall substantially flat, its longitudinal edges, one upper and one lower, being bent to form together with said wall a concavity, the crosswise profile of each bent edge being curved to form a guide track for the wheels of a carriage on each face. According to the invention the crosswise concave or convex profile of the wheels guided along a track is complementary to the crosswise profile of said longitudinal bent and curved edge relative to the face that forms said track so as to keep the wheels constrained to the rail while the carriage is translating. According to the invention each carriage is so shaped to avoid covering one or more parts of the rail and to avoid interference with the means for fixing the rail to the external frame of the cabin.

According to the invention the means for fixing the rail are placed at the ends of said rail.

According to the invention, a suitable combination of the positions of the carriages and of their respective wheels ensures that the means for fixing the rail can be placed at its end and in an intermediate position, to reduce bending when the doors are moving.

In one form of realizing the invention, the carriages are placed on opposite sides of the rail.

In one form of realizing the invention, the carriages are placed on the same side of the rail.

In one form of realizing the invention the wheels of the faster moving carriage are in contact with the longitudinal edges of the rail outside it, while the wheels of the slower moving carriage are in contact with the longitudinal edges of the rail inside the space enclosed by the wall of said rail.

In one form of realising the invention the wheels of the slower moving carriage are in contact with the longitudinal edges of the rail external to it, while the wheels of the faster moving carriage are in contact with the longitudinal edges of the rail inside the concavity in the rail.

In one form of realizing the invention at least one wheel of a carriage is in contact with a longitudinal edge of the rail outside it, while at least another wheel of the same carriage is in contact with the other longitudinal edge of the rail inside the concavity in the rail.

In one form of realizing the invention each carriage is equipped with more than two wheels to increase the transportable load.

In one form of realizing the invention each wheel in each carriage is associated to a counteracting wheel, also called a counter-wheel, guided against the longitudinal bent and curved edge of the rail opposite to the edge on which said wheel is guided, so eliminating clearances between carriage and rail to improve stability of movement.

In one form of realizing the invention that includes four doors of equal width, the rail extends on both sides and said faster moving carriage belonging to the first pair of carriages, is moved along the rail but not beyond the centre, the other part of the rail being travelled in the opposite direction by two additional carriages moved in the same direction to transport respective additional doors, the additional faster carriage being operated by means for transmission of the movement of said faster carriage belonging to the first pair of carriages.

In one form of realizing the invention that includes four doors, the width of two first doors differing from that of the two second doors, the rail extends on both sides and said faster carriage of the first pair of carriages moves along the rail without exceeding the overall width of the two first doors, the other part of the rail being travelled in the opposite direction by two additional carriages moving in the same direction to carry the respective two second doors, the additional faster carriage being operated by means for transmission of movement of said faster carriage belonging to the first pair pf carriages, and the means for transmission of movement between the carriages causing the carriage, whose movement is transmitted, to translate along a stroke of different length.

According to another aspect of the invention, at the position of access from a floor, second rails, similar to the rail on the cabin, are disposed horizontally, the second rails being fixed to the brick wall of the hoistway to support the respective carriages for operating the floor doors, the second carriages being translated in the same direction, one at double the speed of the other synchronized with the carriages on the cabin, by means of a known non-motor- driven device that couples with said motor-driven device transmitting its movement when the two devices are in a correct vertical alignment.

The following are alternative forms of realizing the invention described in a similar number of dependent claims.

The longitudinal bent and curved edges of the rail both present an outward- facing convexity, the wheels in contact with the upper longitudinal edge, external to it, present a groove that couples with the convexity on the upper edge, the wheels in contact with the lower longitudinal edge of the rail, inside the concavity in the rail, being tapered to couple with the inward-facing concavity in the lower edge.

The longitudinal bent and curved edges of the rail both present a convexity facing towards the inside of the concavity in the rail, the wheels in contact with the upper longitudinal edge, external to it, being tapered to couple with the concavity on the upper edge facing outward, the wheels in contact with the lower longitudinal edge, inside the concavity in the rail, presenting a groove that couples with the convexity on the lower edge.

The upper longitudinal bent and curved edge of the rail presents an outward- facing convexity, the lower longitudinal bent and curved edge of the rail presenting a convexity facing towards the inside of the concavity in the rail, the wheels in contact with the upper longitudinal edge, external to it, presenting a groove that couples with the convexity on the upper edge, the wheels in contact with the lower longitudinal edge inside the concavity in the rail presenting a groove that couples with the convexity on the lower edge.

The upper longitudinal bent and curved edge of the rail presents a convexity facing towards the inside of the concavity on the rail, the lower longitudinal bent and curved edge presenting an outward-facing convexity, the wheels in contact with the upper longitudinal edge, external to it, being tapered to couple with the concavity in the upper outward-facing edge, the wheels in contact with the lower longitudinal edge inside the concavity in the rail being tapered to couple with the inward-facing in the lower edge.

Advantages of the invention Thanks to the use of a single rail, the advantage of the system for operating the so-called telescopic doors, subject of the present invention, compared with conventional systems, lies in its considerable reduction of the crosswise bulk of the sliding mechanism. This makes for greater space inside the cabin, a reduction in weight and the saving of one rail no longer used. Doors can also be thinner than the usual ones although the system is in any case perfectly suited to moving doors of great height and considerable weight.

Short description of the figures

Further purposes and advantages of the present invention will be clear from the following detailed description of an example of its realization and from the attached drawings provided purely for explanatory reasons and in no way limitative, wherein:

Figure 1 is a front view of an elevator cabin, access to which is obstructed by two telescopic doors, movement of which is obtained in the conventional manner (the second rail is shown vertically offset);

Figure 2 is . a side view of a rail seen in Figure 1 ;

Figure 3 is a side view of the mechanism for sliding the doors in Figure 1 ; Figure 4 is a front view of an elevator cabin, access to which is obstructed by two telescopic doors moved along the same rail according to the present invention;

Figure 5 is a side view of the rail in Figure 4;

Figure 6 is a side view of the mechanism for sliding the doors in Figure 4; Figure 7 is a front view of an elevator cabin, access to which is obstructed by two pairs of four panel center opening doors moved along the same rail, according to the present invention;

Figure 8 differs from the preceding figure in that the doors have made a partial stroke towards the open position;

Figure 9 is a plan view schematizing the four panel center opening doors of the doors in Figure 7, with their corresponding floor doors;

Figure 10 is a schematization that differs from the preceding figure in being asymmetric.

Detailed description of some preferred forms of realizing the invention In the following description equal elements that appear in different figures may be marked with the same symbols. When describing a figure reference may be made to elements not expressly shown in that figure but in preceding figures. Scale and proportions of the various elements do not necessarily correspond to reality.

Figure 4 exemplifies a system for moving two 'telescopic' doors 20, 21 shown when shut against access to the cabin. The arrows indicate the direction of movement for opening them; the double arrow on door 20 signifies that it is the faster one since it executes the full opening / closing stroke equal to the space for access to the cabin. The single arrow on door 21 signifies that it is the slower one since its stroke is only half that executed by the faster door 20. At the side of the slower door 21 an empty space 22 can be seen that serves to house the sliding movement of both doors when they open. At its upper end, the faster door 20 is fixed to a first carriage 23 (marked with oblique lines), hereinafter called the main carriage which can translate along a horizontal rail 25 that extends horizontally across the width of about three doors; this dimension is not however limited to the width of the cabin. Rail 25 is rigidly joined at the roof to the load-bearing frame of the cabin, but can also be fixed elsewhere, for example to the car sling. The upper end of the slower door 21 is fixed to a second carriage 24, hereinafter called the secondary carriage that translates along the rail 25 at half speed and covering a half stroke. The main carriage 23 is constrained to the rail 25 by two wheels 26a, 26b and by two counter-wheels 27a, 27b. The secondary carriage 24 is also constrained to the rail 25 by two wheels 28a, 28b, and by two counter-wheels 29a, 29b. A limit- stop 30 arrests the carriage 23 at its closed position. The conformation in Figure 4 is not binding since the rail 25 can be laid under the doors 20 and 21. The main carriage 23 is worked directly by the motor-driven device for moving the doors; the secondary carriage 24 is drawn along by the main carriage. Though not seen in the figure, the carriages 23 and 24 are joined by a cord that, by means of a pulley system, gears down movement of the two carriages. In practice, for one unit of stroke of the secondary carriage 24, the double is obtained for that of the main carriage 23. Such a ratio may be defined as 2:1 tackle type.

Figure 5 shows the substantially C-shaped profile of the rail 25, comprising a section of rectilinear wall 35 joined at a right angle at each end to two respective sections of wall 36 and 37 corresponding to the longitudinal edges of the rail 25, said edges being bent and possessing a varyingly curved equal profile. As rail 25 is of a constant thickness it can be made by extrusion of the crosswise profile for its whole length. Otherwise rail 25 can be made by bending or moulding a sheet of suitably rigid metal. On the edges 36 and 37 there is a convexity, respectively numbered 36a and 37a, facing outward on the C-shaped structure. Each convexity has its corresponding concavity 36b, 37b comprised in the concavity of the C-shaped section. The longitudinal flat wall, corresponding to the extension of the rectilinear section 35, lies horizontally in the direction of length and vertically in the direction of the width so that the longitudinal edge 36 is uppermost in relation to the lower longitudinal edge 37. The above convexities on, and concavities in, the longitudinal bent edges 36 and 37 serve as tracks for guiding the wheels of the carriages, as will shortly be explained.

Figure 6 shows the lateral conformation of carriages 23 and 24 and of the wheels visible in figure 4 on the left of the sheet. The figure shows that there is a single rail 25 and that its longitudinal wall 35 is fixed to the outer infrastructure (not illustrated) by fixing means 45 connected at points that do not interfere with translation of the carriages 23 and 24. Carriages 23 and 24 are disposed parallel to the rail 25 one on each side without any limitation; the main carriage 23 is the outermost of the two. The next description concerns positioning of the only wheels seen in the figure, but also concerns the companion wheels aligned in the same horizontal direction. Having stated this, wheel 26a and counter-wheel 27a turn on bearings or bushings held in place by respective pins 41 and 42 fixed to the main carriage 23. In a similar manner, wheel 28a and counter- wheel 29a turn on bearings or bushings held by respective pins 43 and 44 fixed to the secondary carriage 24. In the upper wheel 28a of the secondary carriage 24 there is a peripheral groove 28c that adapts to the convexity 36a on the upper edge of rail 25 on which it rests discharging the weight of the door 21 and of the carriage 24 on the pin 43. Wheel 28a is therefore weight-carrying and as such has a diameter greater than that of the lower wheel 29a, which is not weight-carrying; there is no reason, however, why the diameters should not be the same. In the latter there is a groove 29c that adapts to the convexity 37a on the lower edge of rail 25 with which it is in contact, to eliminate clearances between the carriage 24 and the rail 25 so improving stability of movement.

The circular edge 26c of the lower wheel 26a of the main carriage 23 is tapered to adapt to the concavity 37b on the lower edge of the rail 25 on which it rests discharging the weight of the door 20 and of the carriage 23 on the pin 41.

Wheel 26a is therefore weight-carrying and as such has a larger diameter than the upper wheel 27a, which is not weight-carrying, though there is no reason why the diameters should not be equal. The circular edge 27c of this latter is tapered adapting to the concavity 36b in the upper edge of the rail 25 with which it is in contact to eliminate clearances between the carriage 23 and the rail 25 so improving stability of movement.

Figure 7 shows a system for moving four telescopic doors, two by two, on a single rail 56. The closed position, seen in the figure, is achieved by doubling the conformation of two doors, shown in Figure 4, symmetrically in relation to the centre of the opening for access to the cabin. The figure shows a first pair of doors, 50 and 51, in the left half of the figure, and a second pair, 52 and 53, in the right half of the figure. Arrows indicate the direction, stroke and speed of opening movement of the various doors. In particular they indicate that the two pairs of doors translate in the opposite direction and that, in each pair, the doors translate in the same direction. The central doors 50 and 52 execute a stroke covering half the opening for access to the cabin at double the speed compared with doors 51 and 53 whose stroke covers a quarter of the opening for access. Two lateral spaces, 54 and 55, accommodate the respective pairs of doors 50, 51 and 52, 53 in their fully open position. The horizontal rail 56 situated at the roof of the cabin, sustains a first pair of carriages, 57 and 58, and a second pair, 59 and 60, permitting their translation. Alternatively, rail 56 can be placed under the doors of the cabin. Carriages 57 and 58 are fixed to the respective doors 50 and 51. Carriages 59 and 60 are fixed respectively to doors 52 and 53. Carriages 57 and 59 are the main faster carriages that draw the respective secondary carriages 58 and 60. A central limit stop 61 arrests translation of the main carriages 57 and 59, preventing them from going more than halfway across the space for access to the cabin. The motor-driven device for door movement sets one of the main carriages in motion after which movement is transmitted, by special means, to the second main carriage.

Figure 8 shows more clearly the movement of opening the doors in the four panel center opening doors system in Figure 7.

Figure 9 shows a completed view of the four panel center opening doors conformation in Figure 4, in which the floor doors are also shown. Looking at the plan view in Figure 9 the four doors in Figure 7 will be noted, separated into telescopic pairs 50, 51 and 52, 53 in the position where access to the cabin 65 is closed. On the right and left of cabin 65, in proximity to doors 51 and 53, there are empty spaces 54 and 55 to accommodate the respective doors when open. Hoistway for the cabin 65 is delimited by a brick wall 66 which, in proximity to the floors, presents respective openings for entry and exit of passengers into and out of cabin 65. The brickwork apertures are closed by floor doors that open only when the cabin 65 is aligned with the floor. There are four floor doors 68, 69, 70. 71 grouped in pairs 68, 69 and 70, 71 in a four panel center opening doors conformation like that of the cabin doors. Between the threshold of access to the cabin, flush with the outer cabin doors 50, 52, and the threshold flush with the inner floor doors 68, 70, there is a safety space 67 to avoid contact between the cabin doors and the floor doors. Inside the hoistway for the cabin 65, at each opening in the brickwork 66 for mounting the floor doors, a second rail (not shown) is laid horizontally and identical to the one already described. This second rail permits sliding of the four carriages that carry the door 68, 69 and 70, 71 synchronised with the opposite cabin doors 50, 51 and 52, 53. Movement of the floor doors is operated by a known device without motor, called suspension, placed on each floor at the position of the second rail. This device is only worked by the motor-driven device mounted on the roof of the cabin 65, when the device is vertically coupled at the correct level.

Figure 10 shows a conformation of four asymmetric doors, of the cabin and at a floor, differing from that of four symmetric doors in Figure 9 because the cabin doors 81, 82 and floor doors 88, 89 of a first pair are of a width different from that of the cabin doors 83, 84 and floor doors 90, 91 of the other pair. The width of the empty spaces 85, 86 at the side of the cabin 80 are such that they can accommodate the respective doors in their open position. As already said in the description of Figure 7, the motor-driven device for moving the doors sets in motion one of the two main carriages after which the movement is transmitted, by special means, to the second main carriage. To allow for asymmetry in the width of the doors, the means for transmission of movement are so configured as to obtain different strokes.

Based on the description given of a preferred example of realization of the invention, some changes can obviously be made by an expert in the field without thereby departing from its sphere as will appear from the following claims.