FI93283B - Safety device for lift doors - Google Patents

Abstract

Safety device for lift doors or the like, which lift doors or the like are controlled by a control circuit comprising one or more contacts KD which are connected to a mains voltage V1. To disconnect dangerous voltages in the event of an open lift door, the device comprises a first relay K1, a second relay K2 and a protective transformer T which are connected in such a way that when the contacts KD are closed, the first relay K1 operates in such a way that the second relay K2 pulls in, that the second relay K2 has a holding circuit, and that the first relay K1 is de-energized, and that in the event of an open circuit both relays K1, K2 are de-energized whereby the phase voltage V1 is disconnected from the control circuit. <IMAGE>

Description

93283

LIFTING DOOR SAFETY DEVICE

This invention relates to a safety device for elevator doors according to the preamble of claim 1.

5 Especially in old lifts, safety can be defective in various ways. It is therefore possible that in certain cases dangerous voltages occur in such places where such voltages could not be allowed. Such a situation can occur in the door circuit, in case the phase voltage in the electricity grid, which saturates the door circuit, occurs at the open elevator door.

The ultimate goal of this invention is to eliminate the above-mentioned drawbacks and provide such a safety circuit for elevator doors, which disconnects dangerous voltages at an open elevator door down a junction, which has been described in detail in the following claims.

The voltage from the protective transformer via contactors is completely harmless because:

the secondary voltage does not exceed a low voltage, e.g. 50 V

- the voltage on the door / reading circuit is completely isolated from the ground.

The invention will now be described in more detail below by means of an exemplary genon referring to an accompanying drawing, in which the figure shows the inventive safety circuit for switching off dangerous voltage at an open elevator door.

In the figure, door / reading contacts KD are shown in a door circuit which are connected to the phase voltage Vj (230 V, 50 Hz). Door-35 / reading contacts KD, on the other hand, are connected to an up and down coil ku and kN, son further connected to ground G (0).

2 93283 The safety circuit consists of a first contactor Kw a second contactor K2 and a protection transformer T. The coil kt on the first contactor Klf secondary side on the protection transformer T and two switching contacts 5M-6M and 7M-8 "on the second contactor K2 have been connected in a closed circuit with door / reading contacts KD The primary side of the transformer T is connected between the phase voltage V, and the ground G.

Furthermore, the door / reading contacts KD are connected to the phase voltage V, via a parallel connection of contacts 1'-2 'on the first contactor K, and contacts l "-2" on the second contactor K2. Between the door / reading contacts KD and the coils ku and kN, contacts 3 "-4" on the second contactor K2 are connected, and the coil k2 on the second contactor K2 is connected in parallel with a series connection of the contacts 3 "-4" and the coils ku and kN.

The circuit works in the following way. When the door contacts KD are closed, the contactor Kj works so that the contactor K2 pulls.

The contactor K2 receives a pouring circuit through the contacts l "-2".

At the same time, contacts 5 ”-6” and 7M-8 ”are opened and contactor Ki falls.

At an open door / reading circuit, both contactors Kt and K2 fall, the phase voltage V, being disconnected from the door / reading circuit.

When the door / reading circuit becomes hot, the contactor K2 draws and inputs the contactor K2, which remains drawn over its own pour contact.

30 The circuit in the coil k | and the transformer T is disconnected with switching contacts 5 "-6" and 7 "-8M on the contactor K2.

It will be appreciated by those skilled in the art that the invention is not limited to the example set forth herein, but may vary within the scope of the appended claims. IN

II

93283 3 Instead of a basket door, in older elevators there can be a gate.

Claims (5)

93283 4 A safety device for elevator doors or the like, which elevator door or the like is controlled by a control circuit 5 comprising one or more contacts (KD) connected to a mains voltage (Vt), characterized in that for disconnecting dangerous voltages at an open elevator door in the device a first contactor (KJ, a second contactor (K2) and a protective transformer (T), which are connected so that, when the contacts (KD) are closed, the first contactor (KJ means that the second contactor (K2) draws) , that the second contactor K2 receives a pouring circuit, and that the first contactor (Kt) falls, and that in an open control circuit, both contactors (K, K2) fall, the phase voltage (Vt) being disconnected from the control circuit. Device according to claim 1, characterized in that the contactor (K2) receives a pouring circuit via first contacts (1 "-2"), at the same time opening second contacts (5M-6 ", 7n-8") and first contactor (K ,) falling. 25 Device according to claim 1 or 2, characterized in that when the control circuit becomes heated, the first contactor (K,) and inputs the second contactor (K2), which remains drawn over its own pour contact. 30 Device according to any one of the preceding claims, characterized in that the circuit of the coil (k) of the first contactor (K,) and the transformer (T) is disconnected with switching contacts (5 "-6", 7M-8 ") on the second contactor (K2). 5 93283