APPARECCHIATURA PER IL CONTROLLO A DISTANZA DEI MOVIMENTI DI UNA GRU.

摘要

A control for a crane having a plurality of pressure-activated clutches with a control panel in the cab on a swingable upper works. A lightweight portable control panel is connected by an umbilical cord to the rotating joint and a switch selectively connects either the portable panel or the cab panel to an amplifier. An encoder in each panel provide redundant control signals to the amplifier which amplifies the signal with less noise and passes the amplified signal to a decoder which selects the proper current source to activate a solenoid-actuated hydraulic valve to modulate hydraulic pressure to the clutch selected by operation of a control lever on the selected one of the two panels.