HK1117812B - Safety lock for elevator landing door - Google Patents

Description

Safety lock for elevator floor landing door

Technical Field

The present invention relates generally to an elevator landing door safety lock for detecting the intrusion of a person into a shaft via a landing door and an elevator equipped with such a lock.

Background

It is known that some elevator landing door locks are provided with a bistable safety switch which is activated by the landing door lock key when the door is opened and places the elevator in safe operation so that it cannot be manually reset from inside the hoistway. Nevertheless, the switch position is electrically reset from the elevator machine room. This configuration requires an electrical reset activation device for the bistable switch and corresponding wiring for the landing doors in the elevator machine room. Furthermore, during maintenance operations, the operator needs to perform cumbersome operations in order to reset and move in and out of the elevator machine room accordingly.

Disclosure of Invention

The present invention is designed to overcome these drawbacks and discloses an elevator landing safety lock for detecting the intrusion of a person into a shaft via a landing door, activating a bistable switch via a spindle shaft when the landing door is opened by turning a corresponding key, placing the elevator in safe operation, without the switch being able to be manually reset from inside the shaft, characterized in that it comprises means to fix the lock in the open position in which the door is open, and releasing it when the door is closed, the switch being resettable by turning the lock in the door closing direction, wherein the key is turned in the direction opposite to the opening direction and the switch is mechanically reset by a mechanical device connected to the spindle shaft.

The bi-stable switch is of the type comprising an outwardly projecting drive tab or lever, by moving the lock from a first rest position in which the elevator is controlled in the normal manner to a second position in which the elevator is controlled in safe operation when the door is open, and returning to the rest position in the event that the switch is reset to close the latch when the door is closed.

The bistable switch is protected from manual access by a housing covering it. Its position on the door lintel behind the landing door connection plate actuated by the lock makes it more difficult to access.

When the spindle lever is positioned in the rest position, away from the connecting plate, via at least one helical or coiled spring wound around the lever spindle and bearing on the door lintel by means of two end strands arranged on each side of the spindle, it is advantageous if the end strands of the spring are close to a switch actuation tab which is raised when the door lock is opened and moves the switch tab from its first position to a second position in which the elevator is put into safe operation.

The at least one spring preferably comprises two helical or coiled springs wound fixedly around the rod spindle and in which the outer strands rest on the lintel on either side of the rod spindle, the strand closest to the switch actuation tab turning to contact towards it when the lock opening operation is performed.

The switch drive lug may be driven to move to its second position by a resilient lug or lever in place of a spring end strand that is fixed to the locking lever spindle without rotation and engages the switch drive lug when open.

Said mechanical means connected to the spindle of the lock advantageously comprise a rear projection fixed to the spindle of the lock and moving the switch actuation projection in its rest position when the door is closed and when the lock is turned closed.

Said means for locking the lock open when the door is open are advantageously formed by forming a groove on a lock sleeve fixed on the door lintel, wherein a complementary movable part fits into the groove, pushing towards it and locking the lock in the open position, such movable part being pulled outside the groove by a movable stop fixed on the landing door bearer, which movable stop is arranged in a position to push said movable part outside the sleeve groove when the landing door is closed.

During opening, the sleeve preferably comprises at least one heel which is locked in cooperation with the movable complementary part.

The movable part is advantageously a plate freely mounted to pivot close to the locking sleeve and urged towards it by a spring, which is released by the plate being urged by the door carrier stop.

The invention also relates to an elevator equipped with at least one safety lock as described above.

Drawings

FIG. 1 is a perspective view of a safety lock for an elevator landing according to the invention, the switch being in a normal elevator operating position;

fig. 2 is a corresponding top view of the lock according to fig. 1;

FIG. 3 is a top view in the lock opening operation;

FIG. 4 is a perspective view of the lock with the door open and with the switch lever locked in a second position;

FIG. 5 is a perspective view of the lock showing the closing operation of the reset switch; and

fig. 6 is a top view of the lock corresponding to fig. 5.

Detailed Description

With reference to the figures and in particular to figures 1 and 2, a safety lock 1 for an elevator landing door according to an exemplary embodiment is shown mounted on the upper lintel 3 of the elevator landing door on each landing of a building. It is mounted on a central-opening or laterally-opening landing door, for example two door leaves moving away simultaneously when open and moving closer in the opposite direction when closed.

Which is arranged to engage on the end of the connecting plate 5 of the landing door.

Conventionally, it comprises an external opening 7 in which a lock drive key is mounted, a crank end 11, mentioned as a spindle rod, which engages on an end 13 of the elevator door web during the opening operation in order to lower it and release the closing hook and thus the landing door open, and a stop elevator, open door closing contact 15; it also comprises locking means 17 for a lock mounted on the floor sleeve 19, which locks the lock open once the door is opened.

A bistable switch 21 is also mounted on the lintel 3, facing the end of the spindle rod 11 and located behind the connecting plate 5. This switch 21 comprises a driving tab or movable rod 23 which projects from its body and is driven via the spindle rod 11.

The spindle lever 11 is returned to the rest position (fig. 2) inclined at an angle of approximately 45 ° with respect to the lintel 3 by means of two helical springs 25 coaxially surrounding and fixed to the lever spindle, and the end outer strands 27 of the springs bear on the inner wall of the lintel 3. The outer strand 27 of the spring adjacent the switch 21 is raised when the lock opening operation is performed and engages under the switch lever 23 moving it from the rest position shown where the switch controls normal operation of the elevator to a rotated position where the elevator is placed in safe operation (fig. 3). Thus, when the lock is fully open, the switch lever 23 is rotated to the operating position and remains stable in this position.

Once the landing door is opened, the locking device 17 is moved into position (fig. 4). The locking device drives the movable plate 29, which cooperates with the sleeve 19, and locks it at the latch bottom plate, in particular at its end heel 31.

The plate 29 pivots on a lower spindle 33 fixed to the lintel and is drawn back towards the end heel 31 of the sleeve 19 by a spring (helical springs on the spindle are not shown), fitting therein by the force that pulls them towards each other. The lock 1 is thus locked in the open state and pushed outside the sleeve 19 by the stop 35 (schematically shown) of the door leaf carrier. This stop 35 is suitably arranged on it so as to contact the plate 29, or a part protruding therefrom, for example a rod or screw 37 fixed thereto, and move it a short distance when the door is almost closed.

At this point (fig. 5 and 6), once the door is closed, the lock 1 can be moved in the opposite direction by its key in the closing direction.

The spindle shaft 11, including the upper end projection 39, is turned in the direction of the arrow and bears via it on the stem 23 of the switch 21 in order to return it to its original position, thus resetting the switch 21, so that the elevator is again made to operate normally, while the connecting plate 5 is closed as a result of the door having been closed.

The present invention thus provides a simple mechanism for resetting a bistable elevator landing door safety lock switch to provide a signal that a person has invaded the hoistway on a landing without the need for an electrical reset in the elevator machine room as described in the preamble of the specification.

It is noted that as a variant of the invention, the lock spindle 9 can be arranged at a distance from the web 5, for example on one of the landing door leaves, and can be equipped with suitable return mechanisms for movement on the bistable safety switch 21 as well as on the door web 5, but by means similar to said locking means 17 for locking the lock when opening.

Claims (5)

1. A safety lock for an elevator landing door for detecting intrusion of a person into a doorway via the landing door, the safety lock comprising:

a bistable switch arranged to be activated via the spindle lever to place the elevator in a state of safe operation when the landing door is opened by turning the respective key in an opening direction, the bistable switch being unable to be manually reset from inside the respective elevator shaft;

means for securing the lock in an open position in which the door is open, the means being released when the door is closed, the bi-stable switch being reset by turning the key in a direction opposite to the opening direction;

a mechanical switch setting member arranged to mechanically reset the bistable switch in response to corresponding movement of the spindle shaft when the key is rotated in said opposite direction.

2. A safety lock according to claim 1, wherein said bi-stable switch is a lever or drive tab which extends outwardly, moving by moving the lock from a first rest position in which the elevator is controlled in the normal manner to a second position in which the elevator is controlled in safe operation when the door is open, and returning to the first rest position when the bi-stable switch is reset.

3. A safety lock according to claim 1, wherein said bistable switch is protected from manual access by a housing covering it.

4. A safety lock according to claim 3, wherein said bi-stable switch is located on the door lintel behind a landing door connecting plate actuated by the lock.

5. A safety lock according to claim 1, wherein resetting of the bistable switch is initiated by closing the lock, the upper end projection of said spindle rod moving to bear against the bistable switch to return the elevator to normal operating conditions.