Manipulating equipment with actuating linkage - has switches in coupling between boom and grab stopping motor

摘要

The manipulating equipment has a boom actuated by a linkage driven by an electric motor, and coupled to a grab. Switches are incorporated in the coupling between the boom and the grab, so that if any unexpected force acts on the latter the linkage driving motor is cut off. The grab and boom can be positively coupled by a spring mechanism, there being a pin on the grab actuating a switch on the occurrence of such a force. The spring mechanism can comprise a compression spring extexially in a housing secured to the boom, enclosing and coaxial to the pin.