Patent ID: 8421640
Filing Date: 2013-04-16
Classification: B62D,B66C

Abstract:
1. An improved tractor lift detection system for gantry cranes that interrupts the hoisting circuit of a crane if an unsafe condition is detected in a tractor comprising: at least one sensing device mounted on said tractor to produce a signal of said unsafe condition; a radio receiver mounted on said crane to respond to a multi-channel radio transmitter mounted on said tractor to transmit and receive a lifted signal in; a means for communicating an identification signal from said crane to said tractor; a microprocessor based tractor controller mounted in said tractor that monitors at least one sensor that produces the lifted signal when the tractor is being lifted, wherein the controller responsively produces said unsafe condition signal; and wherein said crane accepts said unsafe condition signal within the first several meters of hoisting to interrupt the hoisting circuit and stop hoisting, but will not accept said unsafe condition signal and will not interrupt hoisting after said crane has been locked on a container for the first several meters of hoisting so as to reduce false triggers.