SAFETY DEVICE FOR MOBILE TYPE CRANE

摘要

PROBLEM TO BE SOLVED: To provide a safety device capable of detecting an abnormal signal about a rising and falling angle to be outputted from a boom angle detector for continuously detecting the rising and falling angle of the boom of a mobile type crane. SOLUTION: A boom angle detection limit switch 24 is provided, capable of detecting a specified angle set in advance for the crane main body of a boom, the specified angle to be detected by the boom angle detection limit switch 24 is stored in the operating device 21 of a safety device 20 so as to be compared with a rising and falling angle obtained from a rising and falling angle signal to be outputted from a boom angle detector 22 when specified angle is detected by the angle detection limit switch 24, and an angle memory and comparison means 21a is provided, which outputs a warning command signal to a buzzer 25 when the rising and falling angle signal is found to have been abnormal wherein the rising and falling angle does not agree with the specified angle.