METHOD AND ARRANGEMENT FOR FORMING A SAFETY SPACE IN THE LOWER PART OF AN ELEVATOR SHAFT

Description

[0001] The present invention relates to a method as defined in the preamble of claim 1 and to an arrangement as defined in the preamble of claim 2 for forming a safety space in the lower part of an elevator shaft.

[0002] A method and an arrangement for forming a safety space in the lower part of the elevator shaft is already known for example from JP-A- 09202557.

[0003] A problem often encountered in modernization projects in old buildings is that safety regulations have changed over the years and no sufficient, safety space as required by today's regulations is provided in the lower part of the existing elevator shaft. In general, a modification to provide more space in the lower part of the shaft is either too expensive or even technically impossible to carry out. For the reasons stated above, safety solutions requiring as little space as possible are generally used.

[0004] In prior art, a safety space in the lower part of an elevator shaft is implemented, if possible, by making the pit forming a safety space deep enough so that a "safety cube" of a size of at least 500*600*800 mm as required, by elevator regulations can be fitted in it at least with the shortest side upward. The problem with this solution is the increased depth of the pit and, especially in the case of modernization, the difficulty of making the pit and a costly implementation.

[0005] In prior art, in cases where it has not been possible to deepen the pit, various safety buffers or supports, mounted either on the floor of the pit or on a shaft wall immediately next to the floor, that can be raised or turned into an upright position to allow maintenance operations, have been used. Another expedient used is to attach to the guide rails an element, e.g. a form-closed, dowel or equivalent, designed to stop the motion of the elevator car.

[0006] International patent application no. WO 99/47447 (FI 980594) discloses a safety device designed for the above-mentioned purpose to ensure a safety space in the elevator shaft during maintenance work. In this solution, the elevator shaft is provided with safety buffers which in a normal situation are in a lying position on the shaft bottom, and which the serviceman raises to an upright position as he enters the elevator shaft from the bottom floor to carry out maintenance work or similar operations. The length of the safety buffers is so designed that, in a failure situation, the elevator car or counterweight can not fall too far down causing injury to a person on the shaft bottom. However, this solution involves the drawback that the safety buffers and their pivot structure occupy some space on the shaft bottom even during normal elevator operation, so this solution is not applicable in implementations required in the case of a very small shaft bottom space.

[0007] Another prior-art solution is disclosed in international patent application no. WO 97/23399. In this solution, a safety system provided between the elevator car and a shaft wall stops the elevator at a certain height from the shaft bottom when necessary. The system comprises stopper elements fixedly mounted on an outer wall of the elevator car or on the car frame and support pillars of a certain length placed on the shaft bottom. For normal elevator operation, the support pillars are turned aside from under the stopper elements. Before maintenance work, inspection or similar operations, the support pillars are turned into an upright position, thus preventing the elevator car from descending too far down in the shaft. The drawback is a complicated and expensive structure because the solution requires several stoppers and switches and other components in order to be functional.

[0008] Special buffer arrangements in general have the drawback of requiring an expensive and complicated structure. A further disadvantage common to special buffers and other support solutions is that they limit the distance of elevator travel during maintenance operation so that it is shorter than the traveling distance from the top floor to the bottom floor. Therefore, during inspection and maintenance operation, the elevator can only be driven through. a distance somewhat less than the entire normal traveling distance.

[0009] The object of the invention is to eliminate the above-mentioned drawbacks and to achieve an economical, reliable and easy-to-use method and arrangement for forming a safety space in the lower part of an elevator shaft. The method of the invention is characterized by what is presented in the characterization part of claim 1 and the arrangement of the invention is characterized by what is presented in the characterization part of claim 2. Other embodiments .of the invention are characterized by what is presented in the other claims.

[0010] The method of the invention has the advantage that, with a simple structure, a safety space as required by the norms can be provided in the lower part of even a low-rise elevator shaft. The solution of the invention is excellently suited for elevators to be modernized and especially for so-called rucksack-type elevators, in which both the buffer and the hoisting point of the car are located in the rear part of the car, the space under the car floor being a continuous space without a car frame intermediate bearer and without a buffer in the middle of the pit. A further advantage is that no extra structures are needed on the bottom of the pit, so the depth of the pit required is very small, thus allowing the elevator car to go as far down as possible in normal operation. The pit need not have a depth larger than that required by normal buffers and passages. An additional advantage is that, by using the solution of the invention, the distance traversed during maintenance and inspection operation becomes the same as in normal operation, the reliability being thus improved.

[0011] In the following, the invention will be described in detail by the aid of an example with reference to the attached drawings, wherein

Fig. 1

presents an elevator car requiring prior-art solutions, in simplified and sectioned side view, and

Fig. 2

presents a safety solution according to the invention in simplified and sectioned side view.

[0012] In the solution illustrated in Fig. 1, an elevator car 2 is seen in an elevator shaft 1, at a position near the bottom floor 4. Although in the following description only the term "elevator car" is used, it refers to all types of car solutions, e.g. those comprising a car frame around the car. To provide the space required for a "safety cube" 9 consistent with elevator standards, it is it is required that the elevator car 2 be stopped completely above the "safety cube". In the approach illustrated in Fig. 1, special safety buffers or support pillars as used in prior art are needed, or the pit 5 has to be made deeper as necessary.

[0013] Fig. 2 presents a solution according to the invention, in which the load-bearing floor 3 of the elevator car 2, or a part of it, is so implemented that it can be turned about a joint 8 into an upright position or a nearly upright position. The joint 8 serving as a hinge is located at the front edge of the elevator car, so that when the floor 3 is raised to the upright position, it simultaneously prevents entry into the elevator car during maintenance operations.

[0014] The car is provided with a limit switch 7, which is so disposed that the raised floor 3 will activate the switch when the floor is in the intended raised position. The solution is so implemented that maintenance operation is only possible after the limit switch 7 has been activated. This ensures that the floor can not remain in the position for normal operation and entry into the car is obstructed during maintenance operation.

[0015] As an additional precaution, the elevator car is provided with a horizontal safety batten 6, which is placed near the junction between the back wall and the floor and is always mounted in place when the floor is in the normal position. The batten is so fastened that it will be released by an upward force of suitable magnitude applied to the floor. Thus, in case the elevator car should fall down over a person on the shaft bottom, the force applied to the floor from below will release the batten and the floor will turn upward about its joint 8.

[0016] By the method of the invention, a safety space is formed in the lower part of the elevator shaft by driving the elevator car 2 to a suitable position in the shaft and raising the car floor 3 at least so far up that the required safety space height is reached in the lowest position of the elevator car. The raising of the floor is preferably implemented by turning the floor upward by its back edge about the hinge 8 at the front edge of the car. When the floor is in the desired position intended for it, the elevator system is informed via the limit switch 7 that the floor 3 is in the position required for maintenance operation or a similar action. The floor can be raised manually. To do this, first the safety batten 6 is released, whereupon the floor is turned to its raised position, in which the floor can be locked.

[0017] It is obvious to the person skilled in the art that the invention is not limited to the example described above, but that it may be varied within the scope of the claims presented below. Thus, for example, the structure of the safety arrangement may differ from that described above in that, instead of a hinged floor, the elevator car is provided with a floor that can be raised straight upward by four points. In this case, the limit switch 7 is so disposed that it will only be activated when the floor is in the intended raised position. Likewise, the floor may consist of e.g. two parts, in which case the floor is turned up from the center either towards the front and rear edges of the car or towards the side walls of the car.

[0018] It is also to be noted that the floor need not necessarily be completely removed aside from its position over the safety space. In the case of large cars it may suffice that only a sufficient part of the floor is removed, raised or turned aside to form the required safety space. The floor may also have a telescoping structure, allowing the floor to be retracted horizontally to positions as close as possible to opposite walls of the car. Likewise, the hinge can then be placed elsewhere than at the very edge of the floor.

Claims

1. Method for forming a safety space in the lower part of an elevator shaft, wherein to form the required safety space, the floor (3) of the elevator car (2) is removed from the position where it is during normal operation, characterized in that, to form the required safety space, the floor (3) of the elevator car (2) is turned upward about a hinge at the front edge of the elevator car into an upright or nearly upright position in front of the door of the elevator car.

2. Arrangement for forming a safety space in the lower part of an elevator shaft, said arrangement comprising an elevator car (2) provided with a floor (3) and moving in the elevator shaft, and that the floor (3) of the elevator car is so implemented that it can be removed away from the position where it is during normal operation in order to form the required safety space in connection with maintenance operation or equivalent, characterized in that the floor (3) is so hinged on the front edge of the elevator car (2) that the floor can be raised by its rear edge into an upright or nearly upright position in front of the door of the elevator car.

3. Arrangement according to claim 2, characterized in that the floor (3) of the elevator car is composed of telescoping parts that can be retracted into each other towards the walls of the elevator car so as to form the required safety space in the central part of the floor of the elevator car.

4. Arrangement according to claim 2 or 3, characterized in that the floor (3) of the elevator car has been mounted in place by means of a safety batten (6) which is so attached to the lower part of the car that in a normal situation the raising of the floor is prevented, but when a force directed upward from below the car reaches an intensity higher than normal, the batten (6) will be detached, releasing the floor to rise upward.

5. Arrangement according to any one of the preceding claims, characterized, in that a limit switch (7) is provided in connection with the elevator car, said limit switch being so implemented that it will give an indication of the floor having been removed into a position for maintenance operation or equivalent.

Ansprüche

1. Verfahren zum Bilden eines Sicherheitsraums in dem unteren Teil eines Aufzugschachtes, in welchem zur Bildung des erforderlichen Sicherheitsraums der Boden (3) der Aufzugskabine (2) von seiner Position, in der er sich während des normalen Betriebs befindet, entfernt wird, dadurch gekennzeichnet, dass zur Bildung des erforderlichen Sicherheitsraums der Boden (3) der Aufzugskabine (2) vor der Tür der Aufzugskabine um ein Gelenk an der Vorderkante der Aufzugskabine in eine aufrechte oder nahezu aufrechte Position gedreht wird.

2. Anordnung zur Bildung eines Sicherheitsraums in dem unteren Teil eines Aufzugschachtes, welche Anordnung eine Aufzugskabine (2) aufweist, die mit einem Boden (3) versehen ist und sich in dem Aufzugschacht bewegt, und dass der Boden (3) der Aufzugskabine so ausgebildet ist, dass er von der Position wegbewegt werden kann, in der er sich während des normalen Betriebs befindet, um den erforderlichen Sicherheitsraum in Zusammenhang mit Wartungsarbeiten oder dergleichen zu bilden, dadurch gekennzeichnet, dass der Boden (3) so an der Vorderkante der Aufzugskabine (2) angelenkt ist, dass der Boden an seiner rückwärtigen Kante in eine aufrechte oder nahezu aufrechte Position vor der Türe der Aufzugskabine angehoben werden kann.

3. Anordnung nach Anspruch 2, dadurch gekennzeichnet, dass der Boden (3) der Aufzugskabine aus teleskopartig zusammenwirkenden Teilen besteht, die in Richtung der Wände der Aufzugskabine ineinander zurückgezogen werden können, um so den erforderlichen Sicherheitsraum in dem zentralen Teil des Bodens der Aufzugskabine zu bilden.

4. Anordnung nach Anspruch 2 oder 3, dadurch gekennzeichnet, dass der Boden (3) der Aufzugskabine mittels einer Sicherheitsleiste (6) in seiner normalen Position montiert ist, die so an dem unteren Teil der Kabine angebracht ist, dass in einer normalen Situation das Anheben des Bodens verhindert wird, jedoch wenn eine nach oben gerichtete Kraft von unterhalb der Aufzugskabine eine Größenordnung erreicht, die höher als normal ist, die Leiste (6) losgelassen wird, womit der Boden zum Anheben freigegeben wird.

5. Anordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass ein Grenzwertschalter (7) in Verbindung mit der Aufzugskabine vorgesehen ist, welcher Grenzwertschalter derart ausgebildet ist, dass er anzeigt, wenn der Boden in eine Position für Wartungsarbeiten oder dergleichen bewegt worden ist.

Revendications

1. Procédé pour constituer un espace de sécurité dans la partie inférieure d'une cage d'ascenseur, où, pour constituer un espace de sécurité, le fond (3) de la cabine (2) de l'ascenseur est enlevé de la position où il se trouve pendant le fonctionnement normal, caractérisé en ce que , pour constituer un espace de sécurité, le fond (3) de la cabine (2) de l'ascenseur est tourné vers le haut autour d'une charnière sur le bord frontal de la cabine d'ascenseur vers une position verticale ou presque verticale en face de la porte de la cabine d'ascenseur.

2. Dispositif pour constituer un espace de sécurité dans la partie inférieure d'une cage d'ascenseur, ledit dispositif comportant une cabine (2) d'ascenseur pourvue d'un fond (3) et se déplaçant dans la cage d'ascenseur, et en ce que le fond (3) de la cabine d'ascenseur est installé de manière à pouvoir être enlevé de la position où il se trouve pendant le fonctionnement normal dans le but de constituer un espace de sécurité nécessaire ensemble avec l'opération de maintenance ou quelque chose de similaire, caractérisé en ce que le fond (3) est articulé sur le bord frontal de la cabine (2) d'ascenseur et que ledit fond peut être levé par son bord arrière vers une position verticale ou presque verticale en face de la porte de la cabine d'ascenseur.

3. Dispositif selon la revendication 2, caractérisé en ce que le fond (3) de la cabine d'ascenseur est composé de parties télescopiques qui peuvent être rétractées l'une dans l'autre vers les parois de la cabine d'ascenseur pour constituer un espace de sécurité nécessaire dans la partie centrale du fond de la cabine d'ascenseur.

4. Dispositif selon la revendication 2 ou 3, caractérisé en ce que le fond (3) de la cabine d'ascenseur a été monté sur place au moyen d'une barre (6) qui est fixée sur la partie inférieure de la cabine pour empêcher, dans une situation normale, la levée du fond, mais que la barre (6) soit détachée lorsqu'une force orientée vers le haut à partir du dessous de la cabine atteint une intensité supérieure à la normale , libérant ainsi le fond vers le haut.

5. Dispositif selon une des revendications précédentes, caractérisé en ce qu'un interrupteur de fin de course (7) est prévu en liaison avec la cabine d'ascenseur, ledit interrupteur de fin de course étant installé de manière à indiquer si le fond est levé vers une position de maintenance ou quelque chose de similaire.

Drawing