Research on Anti-Backward-Tipping Device of Luffing Jib Tower Crane

When the crane jib is in the maximum elevation angle，luffing jib tower cranes can happen to produce accidents of crane jib backward- tipping. The anti-backward-tipping device is the necessary safety device luffing jib tower crane. Based on the study of several anti-backward-tipping devices, this paper analyzes the causes and forced state of crane jib backward- tipping and proposes several factors to be put into consideration in designing anti-backward-tipping device. It proposes a design method and calculation method of dual-spring anti-backward-tipping device, which has been applied and verified in product design.