Dual cantilevered electromagnet-based gripping apparatus

Abstract

A dual cantilevered electromagnet-based gripping mechanism has a reduced number of parts and operates with low power demand properties for use in micro-tool applications. Juxtaposed, cantilever-supported electromagnets, to which object engagement elements, such as gripping pincers, are attached, have their cores made of a low permeability material, such as stainless steel, that does not retain an induced magnetic field once the energizing current is terminated. By controlling the energizing current through the coils of the electromagnets, the magnitude of mutual magnetic attraction against the spring forces of their supporting cantilever arms is defined. This allows mutual separation between the electromagnets and object engagement force to be controlled, for seizure, retention, and release of an object. The displacement vs. current characteristic of the device has a hysteresis profile, which allows the coil energizing current to be reduced to a very low 'sustaining' value that minimizes power dissipation, yet keeps the gripping elements closed on the object. To release the object, the energizing current is controllably reduced, which collapses the magnetic fields in the electromagnets and allows the spring force of the cantilever arms to return the gripping elements to their default open positions.