EP1236670B1 - Safety limit switch for elevator - Google Patents

Abstract

Lift (10) for transporting loads and/or people comprises a lift cage (16) moving in a lift shaft (12) and coupled to a drive, at least one buffer (25) for a counterweight, and an emergency stop switch (34) for switching off the drive. The emergency stop switch is operated by the buffer or a buffer impact surface (28). Preferred Features: The buffer is arranged on the upper and/or lower end of the lift shaft or on the lift cage and/or on the counterweight. The buffer impact surface is arranged on the lift cage and/or on the counterweight or on the upper and/or lower end of the lift shaft.

Description

The invention relates to an elevator for transporting loads and / or persons having the features of the preamble of claim 1.

For safety reasons, the use of buffers is required in elevators, which are usually arranged at the lower and optionally at the upper end of the travel path of the car and an optionally used counterweight. Before the car or the counterweight hit the buffer, the drive of the elevator is switched off by means of a emergency limit switch. For this purpose, usually the power supply of an electric drive motor is interrupted.

The emergency limit switch is usually held laterally on a guide rail of the car and includes a shift lever which cooperates with a switching cam mounted on the car. If the car falls below a predetermined minimum distance to the associated buffer, the shift lever is pivoted by means of the switching curve such that the emergency limit switches off the power supply of the drive motor with further movement of the car. Such a construction has the disadvantage that the shift lever and the associated shift curve must be aligned exactly with each other to ensure that the emergency limit switch is reliably operated. The orientation of the pivot lever to the switching curve must be checked at regular intervals. Another disadvantage arises from the fact that the switching curve to achieve a switching point by the pivoting of the shift lever a relatively large minimum travel path of the car requires. This has the consequence that the elevator shaft below or optionally above the respective final stop of the car must provide a not insignificant infrastructure, so that the pit or the shaft head of the elevator shaft must have an additional depth.

From the JP-A-03018578 For example, a buffer device for an elevator is known which has a buffer switch. The buffer switch can be actuated by a movable plunger of the buffer device. For this purpose, the plunger must be moved by an impending car in the direction of the buffer switch. The operation of the buffer switch takes place only after the impact of the car on the plunger.

Object of the present invention is to develop an elevator of the type mentioned in such a way that simplifies the installation of the emergency limit and the depth of the pit and the shaft head can be reduced.

This object is achieved by a lift with the features of claim 1.

In the invention, the idea flows in that the positioning and adjustment of the emergency limit switch can be considerably simplified by being actuated by the buffer or a buffer impact surface associated with the buffer. It only requires the buffer in the direction of movement of the car and possibly the counterweight to the associated Pufferauftrefffläche align, so that then limited to one of the travel of the car or the counterweight reliably and on the other hand, the emergency limit switch can be safely actuated when approaching the car or the counterweight to the associated buffer. Positioning errors when aligning the emergency limit switch are avoided. In addition, the construction according to the invention makes it possible to reduce the depth of the shaft pit and the shaft head, since the when using a laterally arranged pivot lever and an associated Switching curve required large switching paths can be significantly reduced.

The buffer may be located at the top and / or bottom of the elevator shaft and the associated buffer landing surface may be located on the car and / or at the counterweight. However, it may also be provided a reverse arrangement such that the buffer on the car and / or the counterweight and the Pufferauftrefffläche at the upper and / or lower end of the elevator shaft is arranged.

The emergency limit switch can be actuated without contact by the buffer or the buffer impact area associated with the buffer, for example in the form of a proximity switch, in particular a magnetic field sensor, which detects falling below a minimum distance between the car or counterweight on the one hand and buffer on the other hand and then provides an electrical control signal.

In a working with a particularly short switching paths embodiment of the elevator according to the invention it is provided that the emergency limit switch mechanically, for example by pressurization, can be actuated. For this purpose, in particular pressure-sensitive switching elements can be used, with the help of which the mechanical contact between the buffer and the associated Pufferauftrefffläche can be detected.

In an economically producible embodiment, it is provided that the emergency limit switch is held on the buffer and can be actuated by the buffer contact surface. It is advantageous if the emergency limit switch immovable is fixed to the buffer and by the buffer associated, arranged on the car and / or the counterweight Pufferauftrefffläche is actuated. It is favorable if the emergency limit switch can already be actuated before the buffer contact surface makes contact with the buffer. The emergency limit switch can also be arranged in the buffer next to the buffer or with a correspondingly high buffer execution.

In a preferred embodiment it is provided that the emergency limit switch the Pufferauftrefffläche assigned for example held on the car and / or the counterweight and can be actuated by the buffer. It is advantageous if the buffer forms a button through which an actuating element of the emergency limit switch can be actuated.

It is advantageous if the buffer impact surface is arranged on a stop which is positioned on the car and / or on the counterweight or in the elevator shaft. The emergency limit switch can advantageously be arranged on or in the stop.

To simplify the mounting of the emergency limit switch, it is advantageous if the car associated with the buffer stop is held, which forms the Pufferauftrefffläche, and if the emergency limit switch is arranged on the stop. The installation of the emergency limit switch can thus be done together with the mounting of the stop.

To ensure that the drive of the elevator can be switched off as soon as the car or counterweight falls below a minimum distance to the buffer, It is advantageous if the emergency limit switch has an over the Pufferauftrefffläche in the direction of the buffer projecting actuator, such as a switch plunger.

The stopper is preferably plate-shaped, wherein the emergency limit switch is disposed on the rear side facing away from the buffer of the stop and the actuating element engages through a passage opening of the stop and projects in the direction of the buffer.

Figur 1:

eine schematische Darstellung eines unteren Endbereichs einer ersten Ausführungsform eines Aufzugs, wobei ein Schaltstößel eines Notendschalters einen Puffer berührt;

Figur 2:

den unteren Endbereich des Aufzugs gemäß Figur 1, wobei der Notendschalter seinen Schaltpunkt erreicht hat;

Figur 3:

den unteren Endbereich des Aufzugs gemäß Figur 1 beim Auftreffen des Fahrkorbs auf den Puffer;

Figur 4:

den unteren Endbereich des Aufzugs gemäß Figur 1 beim Zusammendrücken des Puffers;

Figur 5:

eine ausschnittsweise schematische Darstellung eines unteren Endbereichs eines Aufzugs (nicht Teil der Erfindung) und

Figur 6:

eine ausschnittsweise schematische Darstellung eines unteren Endbereichs eines Aufzugs (nicht Teil der Erfindung).

The following description of preferred embodiments of the invention is used in conjunction with the drawings for further explanation. Show it:

FIG. 1:

a schematic representation of a lower end portion of a first embodiment of an elevator, wherein a switch plunger of a emergency limit switch contacts a buffer;

FIG. 2:

the lower end portion of the elevator according to FIG. 1 wherein the emergency limit switch has reached its switching point;

FIG. 3:

the lower end portion of the elevator according to FIG. 1 when the car strikes the buffer;

FIG. 4:

the lower end portion of the elevator according to FIG. 1 while squeezing the buffer;

FIG. 5:

a fragmentary schematic representation of a lower end portion of an elevator (not part of the invention) and

FIG. 6:

a fragmentary schematic representation of a lower end portion of an elevator (not part of the invention).

In the FIGS. 1 to 4 is a schematic representation of a total occupied by the reference numeral 10 elevator shown with two along a hoistway 12 extending guide rails 14, 15 to which a car 16 by means of guide elements 22, 23 and a known per se and therefore not shown in the drawing drive, for example an electric drive, is kept movable. In the FIGS. 1 to 4 only the lower end of the hoistway 12 is shown, which forms a shaft pit 18 in this area with a horizontally extending shaft bottom 19 and vertically oriented shaft walls 20th

Below the elevator car 16, a deformable, energy-storing or energy-dissipating buffer 25 is arranged at the bottom of the shaft 19 at the lower end of the travel path of the elevator car 16.

The buffer 25 is associated with a stop in the form of a stop plate 26 on the car 16, which forms a Pufferauftrefffläche 28 on its front side facing the buffer 25. If the car 16 is moved beyond an end stop (not shown in the drawing) in the direction of the shaft bottom 19, the buffer impact surface 28 strikes the end face 30 of the buffer 25 facing the car 16, which deforms upon further movement of the car 16 and the movement of the car 16 stops.

To ensure that the drive coupled to the elevator car 16 of the elevator 10 is turned off before the car 16 strikes the buffer 25, on the buffer 28 remote from the rear side 32 of the stop plate 26 a emergency limit switch 34 is arranged, with the help of the power supply of the Electric drive can be interrupted. The emergency limit switch 34 comprises an actuating element in the form of a spring-loaded switch plunger 36, which passes through a through hole 38 of the stop plate 26 and projects beyond the Pufferauftrefffläche 28 in the direction of the buffer 25.

Approaches the car 16 to the buffer 25, the contact switch 36 contacted falls below a predetermined by the length of the switch plunger 36 minimum distance between the car 16 and buffer 25, a button forming end face 30 of the buffer 25 so that the emergency limit switch 34 is actuated and thereby the Drive is switched off. Upon further approximation of the car 16 to the buffer 25 of the switch plunger 36 is inserted against its spring load in a housing of the emergency limit switch 34, without this case the switching state of the emergency limit switch 34 changes. Upon further approach of the car 26 to the buffer 25 hits the Pufferauftrefffläche 28 of the stop plate 26 on the end face 30 of the buffer 25, so that this is then mechanically deformed, as in FIG. 4 is shown.

The emergency limit switch 34 is in the in the FIGS. 1 to 4 shown embodiment, held on the car 16 and is actuated by the stationary buffer 25. Alternatively, it could of course also be provided, the emergency limit switch 34 on the buffer 25, for example to fix laterally. In this case, the switch plunger 36 can project beyond the end face 30 in the direction of the car 16. When approaching the car 16 to the buffer 25 then hits the Pufferauftrefffläche 28 on the switch plunger, so that the emergency limit switch is mechanically operated.

In FIG. 5 is shown in sections the lower end portion of an elevator 40 (not part of the invention), which is constructed with the exception of the emergency stop switch used as the elevator 10, so that for identical components the same reference numerals as in FIGS. 1 to 4 were used. The elevator 40 also includes a car 16, which carries on its the bottom of the shaft 19 facing bottom of the buffer 25 associated stop plate 26. While at the in the FIGS. 1 to 4 illustrated elevator 10 is a mechanical emergency limit switch 34 is used with a switch plunger 36, comprises in FIG. 5 illustrated elevator 40 a emergency limit switch 42 with an actuating element in the form of a pressure-sensitive switching film 44. The latter covers the buffer 25 facing Pufferauftrefffläche 28 of the stop plate 26 and occurs upon impact of the car 16 on the buffer 25 with the latter in mechanical interaction, wherein the pressure load occurring the switching foil 44 is actuated and thereby a power supply of the drive used is interrupted.

In FIG. 6 the lower end portion of an elevator 50 (not part of the invention) is shown, wherein the same reference numerals are used for identical components as in FIG. 5 , The elevator 50 differs from the above-described elevator 40 only in that the switching film 44 is not disposed on the Pufferauftrefffläche 28 of the stop plate 26, but between the stop plate 26 and the car 16. The switching foil 44 is actuated by the buffer 25 by the buffer 25th a pressure load on the rear side arranged switching film 44 is exerted on the stop plate 26.

Claims (12)

1. A lift for conveying loads and/or persons, having a lift cage (16) which is movable in a lift shaft (12) and to which a drive is coupled, and having at least one buffer (25) which is associated with the lift cage (16) and/or a counterweight associated with the lift cage (16), and having an emergency limit switch (34) for switching off the drive, characterized in that as the lift cage (16) approaches the buffer (25) the emergency limit switch (34) is capable of being actuated by the buffer (25) or a buffer-impact face (28) associated with the buffer (25), before the lift cage (16) strikes the buffer (25).
2. A lift according to Claim 1, characterized in that the buffer (25) is arranged on the upper and/or lower end of the lift shaft (12) or on the lift cage (16) and/or on the counterweight, and the buffer-impact face (28) is arranged on the lift cage (16) and/or on the counterweight or on the upper and/or lower end of the lift shaft (12) respectively.
3. A lift according to Claim 1 or 2, characterized in that the emergency limit switch (34) is capable of being actuated mechanically.
4. A lift according to Claim 1, 2 or 3, characterized in that the emergency limit switch (34) is capable of being actuated by being acted upon with pressure.
5. A lift according to any one of Claims 1 to 4, characterized in that the emergency limit switch is held on the buffer (25) and is capable of being actuated by the buffer-impact face (28).
6. A lift according to any one of Claims 1 to 4, characterized in that the emergency limit switch (34) is associated with the buffer-impact face (28) and is capable of being actuated by the buffer (25).
7. A lift according to Claim 6, characterized in that the buffer (25) forms a switch face (30) by which an actuation element (36) of the emergency limit switch (34) is capable of being actuated.
8. A lift according to any one of the preceding Claims, characterized in that the buffer-impact face (28) is arranged on a stop (26), wherein the stop (26) is arranged on the lift cage (16) and/or on the counterweight or in the lift shaft (12).
9. A lift according to Claim 8, characterized in that the emergency limit switch (34) has an actuation element (36) which projects beyond the buffer-impact face (28) in the direction towards the buffer (25).
10. A lift according to any one of the preceding Claims, characterized in that the emergency limit switch (34) comprises a switch plunger (36).
11. A lift according to Claim 8, 9 or 10, characterized in that the emergency limit switch (34) is arranged on or in the stop (26).
12. A lift according to Claim 8, 9, 10 or 11, characterized in that the stop (26) is designed in the form of a plate, wherein the emergency limit switch (34) is arranged on the rear side (32) of the stop (26) facing away from the buffer (25) and the actuation element (36) passes through a through-opening (38) in the stop (26) and projects in the direction towards the buffer (25).

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