SU590231A1 - Construction hoist safety device - Google Patents

Description

(54) SAFETY DEVICE FOR CONSTRUCTION LIFT

one

The invention relates to the field of lifting machines, in particular to construction hoists.

Known lift, on the carrying body of which is placed a limit switch that interacts with the stop, located in the upper part of the lift mast, and disconnecting the control circuit of the lift

sh

The disadvantage of the known devices is that a cable should be laid along the mast to a limit switch, or a moving load-carrying member should be equipped with a power supply cable.

Closest to the invention is a safety device for a construction hoist containing a cable connected to a control circuit limit switch - a lifting electric motor; .

A disadvantage of the known device is that the contacts of the limit switch are included in the drive motor control circuit and open when the clamp, attached to the additional cable, interacts with the plug mounted on

platform. In the case of sticking of the magnetic starter, the power circuit is not interrupted and the platform, having reached the top position, continues to move, which leads to an accident.

The purpose of the invention is to increase safety.

The goal is achieved by the fact that a double-arm lever is hinged on the mast of the lift, the cargo cable is provided with a stop,

and an additional switch is introduced into the power supply circuit of the lift motor, with one shoulder of the two shoulders of the lever made in the form of a T-shaped frame, covering the cargo cable and the interacting one with an emphasis, and

on the other shoulder fixed cam, acting on the additional switch.

FIG. 1 shows a lift with a device, a general view; in fig. 2 — node I in FIG. one;

in fig. 3 is a section along A-A in FIG. 2; in fig. 4 - power circuit of the device; in fig. 5 - control circuit.

The device is a cable I, pulled along the mast 2 of the lift and connected below with the limit switch 3 of the motor control circuit 4. At the upper end of the cable I is mounted a clip 5, which interacts with a fork 6 mounted on a loading platform 7 lifted

cargo cable 8 winches 9. On the cable 8

there is a stop 10, interacting with two shoulders lever 11, pivotally mounted on the base 12, mounted on a lift. One shoulder of two shoulders, And, made in the form of a T-shaped frame 13, covering the cable 8; and the other shoulder is in the form of a stop cam 14 interacting with the switch 15 of the power circuit of the electric motor 4. The cam 14 rests on the spring clip 16.

To start the electric motor 4, there are buttons 17 and 18, the closing circuits of the coils 19 or 20 of the reversing magnetic actuator, the power contacts 21 of which close the power circuit. The contacts 22 of the switch 3 are included in the coil of the actuator coil 19, which serves to activate the upward movement. The contacts 23 of the switch 15 are included in the power circuit of the electric motor 4.

When the platform 7 moves upwards in the upper extreme position, the plug 6 interacts with the clamp 5 of the cable 1, as a result of which the switch 3 opens the contacts 22 interrupting the coil circuit 19 of the magnetic starter. His contacts 21 must with this. open the power circuit of the electric motor 4. If the contacts 21 are stuck, then with further upward movement of the platform 7, the support 10 fixed to the cable 8 interacts with the frame 13 of the two shoulders lever 11, moving it downwards. In this case, the cam 14 acts on the switch 15, the contacts 23 of which interrupt the power circuit of the electric motor 4, and the platform 7 stops.

To turn on the switch 15, it is necessary to loosen the latch 16, thereby releasing the double-shouldered lever 11, acting by YOUR cam 14 on the switch 15.

After turning on the switch 15, it is possible to lower the platform 7 of the elevator.

Claims (2)

1. Galichenko A.I., Hecht A. X. Construction elevators. M., 1975, p. 88 2. USSR author's certificate number 351777, cl. In 66B 13/24, 1971. 15 CPUS.3 ifui.f FIG. five