GB2356623A - Locking device for elevator doors - Google Patents

Description

2356623 LOCKING DEVICE FOR ELEVATOR DOORS The present invention relates to

a locking device for locking elevator or lift doors.

More particularly, the present invention relates to a device for locking and unlocking the doors of elevator car in emergency conditions.

As is known, elevators having automatic doors, irrespective of whether the opening is central, lateral or telescopic, are provided with safety devices to allow the opening of the car doors in emergency conditions. Such safety devices allow the opening to take place only at the time when the elevator car is in an unlocking zone, which substantially coincides with the alignment of its base with the floor level. These devices, whose adoption is imposed by specific safety norms, are at present realised in various ways which, while ensuring an adequate operation, have some severe drawbacks. One of these drawback lies in that the known safety devices generally comprise complex and bulky apparatuses, whose installation is consequently laborious. Also, the periodic maintenance of these devices can require complicated interventions, increasing the times of enforced standstill of the system.

The present invention seeks to obviate or reduce the above drawbacks.

More particularly this invention seeks to provide an emergency locking and unlocking device for elevator car doors that is extremely compact and easily installable.

The invention still further seeks to provide a device with easy access during the periodical maintenance and which is, if necessary, easily and rapidly replaceable, without the need of long and laborious interventions.

The invention also seeks to provide users with a device as defined above, suitable to ensure a high degree of resistance and reliability in the time, and also such as to be easily and economically realisable.

According to the invention there is provided a device for locking and unlocking the doors of elevator cars in emergency conditions comprising an actuator carriage with two blades kept together by a motor and elastically tensioned by a spring interposed between said blades, and a tilting door latch of the floor doors comprising a mobile arm provided with a catch suitable to engage in a locking seat, wherein said actuator carriage comprises a plate-like lever located near the blades and aligned therewith, and at least a projection located in contact with the plate like lever and integral with the tilting door latch; and said lock is provided with at least a moving - 2 m means that acts on the projection, unhooking the tilting door latch, and on the mobile arm disengaging the catch from its seat when the motor is not energised and both blades are moved away from each other by spring.

The invention will now be described in greater detail, by way of example, with reference to the drawings, in which:- Figure 1 shows a schematic view of the device of the present invention in the normal working condition of the elevator, during the car movement; Figure 2 shows the schematic view of the same device in emergency conditions, with the car located outside the unlocking zone; and Figure 3 shows the schematic view of the same device in emergency conditions, with the car located in the unlocking zone.

Referring to the drawings, a device of the present invention, indicated as a whole by 10, is advantageously coupled to the carriage forming part of the door actuator (not shown) and interacts with the conventional blades 12, 14 which prevent or allow the opening of the elevator doors.

As specified above, opening of the doors is prevented when emergency situations occur with the car placed outside the locking zone, i.e. not aligned with the floor. A typical emergency situation is one that occurs in case of interruption of the electric current feed or, more seldom, in case of breakdown of the motor or a belt which prevents correct movement of the doors.

Blades 12, 14 are connected to a conventional support 16 and, in case of emergency, are automatically caused to move away from one another, as the force that the motor exercises to hold them together ceases. Such moving apart of blades 12, 14 is carried out by a spring 18 or like elastic means, shown schematically on Figures 2 and 3, and interposed between the blades.

The blades 12, 14 are shown in totally approached position in Figure 1, i.e. in normal working conditions of the elevator whose car is free to move along its line or axis, indicated by 20, of the related lift space. The same blades 12, 14 are shown in a parted position under the effect of spring 18, in Figures 2 and 3, in emergency situations with a non working motor.

In the present invention, the locking and unlocking device of elevator car doors, in emergency conditions comprises a lever 22, connected to a support 24 and formed by a shaped plate-like body located near the blades 12, 14 and aligned therewith.

3- Lever 22 has, on the side facing blades 12, 14, an edge 22' orthogonally developed and extending both in the upper and the lower directions, into an angle oriented extension or lip 26. This extension or lip 26 constitutes an engagement means for at least a movement means 28, suitable to interact with the lever 22, as will be described hereafter.

Also, the device 10 of the present invention comprises a tilting door latch 30, bearing at one end a member or bridge 32 that controls the closing of a lock formed by the same bridge and a complementary engagement or contact seat 34.

From the tilting door latch 30, having its own fulcrum, known per se, on said actuator carriage, there protrudes a projection 36, which develops orthogonally with respect to the door latch and faces an aperture 38 formed on lever 22. Projection 36 is preferably constituted by an eccentric pin, fixed to the latch bolt 30 in such a position as to strike the edge 22' of lever 22 on the side facing the aperture 38. The aperture 38 extends along the lever 22, starting from said edge 22'.

The movement means 28, intended for interacting with lever 22, is fixed on a mobile arm 42 of each of the locks of the floor doors, as known per se. One of these locks is indicated as a whole by 40 in the attached figures.

The moving arm 42 of lock 40 is provided at one end with a catch 44, adapted to engage in a corresponding locking seat 46. Catch 44 is disengaged from seat 46 only when the car is in the unlocking zone, i.e. level with the floor, and thus allows opening of the doors.

The movement means 28 is advantageously constituted by a suitably sized wheel, roller, runner or the like, fixed by a pin 28' or like fastening means to the arm 42 of each of the locks 40 of the floor doors.

The width extension of the movement means is such that, in normal working conditions of the elevator, the movement means passes into the space existing between the edge 22' and the blade 12; while in emergency situations with blades 12,14 moved apart, the means 28 intercepts lever 22 which is thereby moved laterally and acts on projection 36, unhooking the tilting door latch 30 and the mobile latch 42, disengaging catch 44 from seat 46. In particular, the outer diameter of the wheel or roller 28 is smaller than the distance or span between edge 22' of lever 22 and blade 12, in normal working conditions, i.e. when said blade has approached the other blade 14, as shown in Figure 1, and slightly greater than this distance in emergency situations.

-4, When an emergency situation occurs which is traditionally constituted by the interruption of electric current, the elevator car stops moving at the point it has reached, in the majority of cases outside the unlocking zone, i.e. not level with the floor. In such conditions, the device of the present invention steps in to prevent the opening of the doors until the car reaches, through specific external interventions, the level coinciding with said unlocking zone. In detail, upon the occurrence of the emergency, blades 12, 14 automatically move away from each other, under the action of spring 18, as the pushing action of the motor that keeps them together does not work any longer. The tilting door latch 30 remains instead fixed, with the control bridge 32 coupled to contact 34. This condition is shown schematically in Figure 2.

When, following an external intervention, the car reaches the unlocking zone, the device 10 meets the lock of the floor door 40, and is caused to interact with wheel or roller 28. The latter strikes initially the lower or upper lip 26, depending on whether the car has been caused to descend or to rise, of the edge 22' of lever 22. This lip forms an engagement surface for the wheel or roller 28, which progressively moves between the edge 22' and blade 12. As the diameter of wheel or roller 28 is greater than the span existing in the emergency condition between edge 22' of lever 22 and blade 12, the roller or wheel 28 causes the lever 22 to move in a horizontal plane with respect to blade 12. As the projection or eccentric pin 36 is in engagement with edge 22' of lever 22, as it protrudes from aperture 38 of the lever, the tilting door latch 30 is also shifted. The pin 36 is, in fact, integral with the door latch. As a consequence, the latter is caused to tilt, causing the disengagement of bridge 32 from the complementary engagement seat 34. At the same time, the roller or wheel 28 shifts the mobile arm 42, moving catch 44 away from seat 46. Only in these conditions can the car doors of the elevator be opened by hand.

As can be inferred from the above, the advantages achieved by the invention are obvious.

The emergency locking and unlocking device of the present invention allows not only the manual opening of the car doors in safe conditions, in compliance with the norms in force, but is also extremely compact, having at the same time structural characteristics suitable to allow the easy installation and simple access for the periodical maintenance operations. Given its structure, the device of the present invention may also be integrally replaced, if necessary, to install a like or equivalent device without involving long and difficult operations.

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Claims (8)

1 A device for locking and unlocking the doors of elevator cars in emergency conditions comprising an actuator carriage with two blades kept together by a motor and elastically tensioned by a spring interposed between said blades, and a tilting door latch of the floor doors comprising a mobile arm provided with a catch suitable to engage in a locking seat, wherein said actuator carriage comprises a plate-like lever located near the blades and aligned therewith, and at least a projection located in contact with the plate like lever and integral with the tilting door latch; and said lock is provided with at least a moving means that acts on the projection, unhooking the tilting door latch, and on the mobile arm disengaging the catch from its seat when the motor is not energised and both blades are moved away from each other by spring.

2. The device according to claim 1, wherein the plate-like lever is provided with an orthogonally extending edge having the opposed ends extending in an extension or lip, angle oriented and forming an engagement mouth for the moving means.

3. The device according to claim 1 or 2, wherein the moving means is constituted by a wheel, roller or runner having an outer diameter smaller than the distance between edge of the plate-like lever and a blade in normal working conditions, and slightly longer than this distance in emergency situations.

4. The device according to any of the preceding claims, wherein in that plate-like lever is provided with an aperture through which the projection protrudes.

5. The device according to claim 4 wherein the projection is constituted by an eccentric pin fixed to door latch and adapted to strike the edge of plate-like lever in the inside of aperture.

6. The device according to claim 4 or 5, wherein that aperture extends along the plate-like lever starting from edge thereof.

7. The device according to any of the preceding daims, wherein the tilting door latch has its fulcrum on the actuator carriage and is provided at one end with a closing member or bridge which engages in a complementary seat or contact and, at the opposite end, with the protruding projection that extends orthogonally with respect to the plane of said door latch.

8. A device for locking and unlocking the doors of elevator cars in emergency conditions and substantially as described herein with reference to the drawings.