Safety devices for tower cranes

 

(1) When lifting an object with a tower crane, the product of the lifting radius and the weight of the object is an invariant constant. According to this principle, a lifting torque limiter has been made, which is mainly used as a safety device to prevent overloading. The torque limiter only protects against overload torque in the longitudinal vertical plane of the tower crane boom, and cannot prevent tipping accidents caused by inclined lifting, wind load, track tilting or collapse, etc.

 

(2) The function of the lifting weight limiter is to protect the weight of the lifted object from exceeding the allowable maximum lifting capacity of the tower crane, and to prevent the weight of the lifted object from exceeding the rated load and avoid mechanical damage accidents.

 

(3) The lifting height limiter is a device used to limit the hook from coming into contact with the head of the lifting arm or the load car, or before lowering to a point (on or below the ground, if dry meters), to automatically power off and stop the lifting mechanism, preventing damage to the lifting arm due to excessive lifting of the lifting hook.

 

(4) The amplitude limiter is a device used to limit the boom from exceeding its limit position during pitch. When the pitch of the crane reaches a certain limit, an alarm is issued, and when the limit position is reached, the power supply is automatically cut off.

 

(5) Travel limiter: ① Trolley travel limiter: located at the head and root of the trolley's variable amplitude lifting arm, used to cut off the circuit of the trolley's traction mechanism and prevent the trolley from offside. ② Crane travel limiter: used to prevent crane derailment.

 

(6) Rail clamp is a device used to clamp steel rails and prevent tower crane derailment and overturning accidents caused by wind blowing when traveling in strong winds.

 

(7) The anemometer automatically records the wind speed and alarms when the wind speed exceeds level six or above.

 

(8) The steel wire rope anti detachment device is mainly used to prevent the steel wire rope from detaching from the pulley groove during the transmission process, resulting in the steel wire rope being damaged

 

(9) Hook insurance is a device used to prevent accidents such as unhooking of the lifting steel wire rope and falling of objects due to excessive angle or improper hooking of the lifting steel wire rope