Introduction of Tower Hang Accessories-Tower crane Hang Limit Device
Tower hanging limit device is an indispensable part of Tower hanging, is the safety guarantee of Tower hanging, tower hanging must have which kinds of limit device?
Tower hoist shall be equipped with lifting weight limiter, moment limiter, height limiter, stroke limiter, amplitude limiter, etc..
(1) Starting weight limiter
Also known as the overload limiter, it is a kind of insurance device that can make the crane not overload. When the lifting weight exceeds the rated weight, it can automatically cut off the power stop of the lifting mechanism or issue an alarm. There are two types of lifting limiters: mechanical and electronic.
(2) Torque limiter
For variable-frame cranes, a certain range is only allowed to lift a certain amount of lifting. If overweight, there is a risk of tipping. The torque limiter is a kind of protective device based on this characteristic. At a certain degree, if the hanging material exceeds its corresponding weight, the circuit is cut off, so that the lifting can not be carried out, ensuring the stability of the crane. There are three types of torque limiters: mechanical, electronic and composite.
(3) High Restrictor
Also known as hook height limiter. It is generally mounted on the head of the lifting arm. When the hook slides to the limit position, it lifts the lever. Press down the limited-position switch, cut off the circuit parking, and when the switch is closed again, the hook can only drop.
(4) Trip Restrictor
A safety device designed to prevent a crane from crashing or to restrict movement within a certain range. It is generally installed on the inside of the active stage car, mainly equipped with a trip switch that can be dialed and pulled.
In addition, a fixed limit position baffle is installed at the end of the track(in a limited position). When the tower crane runs to this position, the limit baffle touches the trigger of the stroke switch and cuts off the power source that controls the walk. When re-closing, the tower crane can only run in the opposite direction.
(5) Range Restrictor
Also known as variable amplitude limit or amplitude indicator, a range indicator is attached to the lifting arm of a general arm crane.
It is made up of a fixed circular indicator plate, with a prolapse movement pointer in the center of the disk. When the amplitude varies, the pointer indicates the rated starting weight at various ranges.
When the arm rod runs to the upper and lower limit positions, press down the limit switch, cut off the main control circuit, and change the motor to stop the motor to reach the limit position.
