Jib crane with remote controlled hydraulic drive - has reference and actual value comparator and amplifier and servo system

摘要

The remote controlled system control stand incorporates the reference value generator. All other control elements are arranged on the crane itself as a unit. Control signals are transmitted from the control stand to the crane by cable or by wireless signals. The reference value generator is connected by remote control line to the actual value signal generator on a reference value amplifier. This reference value amplifier is connected to the load side power amplifier and those in turn are connected to the hydraulic or pneumatic servo-system and a valve which forms a unit. This unit is relatively small and the electrical conductors are readily shielded so that the system is not sensitive to inductive stray currents which could otherwise lead to uncontrollable malfunctioning of the whole system.