During the use of bridge cranes, accidents caused by the failure of safety protection devices account for a high proportion. In order to reduce accidents and ensure safe use, bridge cranes are usually equipped with various safety protection devices.
1. Lifting capacity limiter
It can make the weight of the lifted object not exceed the specified value, including mechanical type and electronic type. Mechanical use of spring-lever principle; The lifting weight of the electronic type is usually detected by the pressure sensor. When the allowable lifting weight is exceeded, the lifting mechanism cannot be started. The lifting limiter can also be used as a lifting indicator.
2. Lifting height limiter
A safety device to prevent the crane trolley from exceeding the lifting height limit. When the crane trolley reaches the limit position, the travel switch is triggered to cut off the power supply. Generally, there are three types: heavy hammer type, fire break type and pressure plate type.
3. Running travel limiter
The purpose is to prevent the crane trolley from exceeding its limit position. When the crane trolley reaches the limit position, the travel switch is triggered, thus cutting off the power supply. There are usually two types: mechanical and infrared.
4. Buffer
It is used to absorb the kinetic energy when the crane hits the terminal block when the switch fails. Rubber buffers are widely used in this device.
5. Track sweeper
When the material may become an obstacle to operation on the track, the crane traveling on the track shall be equipped with a rail cleaner.
6. End stop
It is usually installed at the end of the track. It prevents the crane from derailing when all safety devices such as the travel limit of the crane trolley have failed.
7. Anti-collision device
When there are two cranes operating on the same track, a stopper shall be set to prevent collision with each other. The installation form is the same as that of the travel limiter.
