Electromagnetic devices

Claim 1

An electromagnetic device of the kind comprising first and second relatively movable magnetizable members, an electrical winding means, the first of said members including a plurality of slots disposed in side by side relationship, the second of said members including a plurality of projections entering into said slots respectively and of a smaller width than said slots, one opposed side face of each slot and each projection defining attraction faces and the other two opposed faces defining trailing faces, said winding means wound in said slots, the connection of the winding means being such that at least two spaced slots have the flow of current in the winding means therein in the same direction and separated by at least one interposed slot in which such directional flow of current is absent, the winding means in the slots being secured on the trailing faces of the slots, whereby when said windings are energized the members will move to reduce the gap between said attraction faces, a coating of a low resistance material secured to the trailing faces of the projections such that eddy currents are generated in the coating, said eddy currents creating a magnetic field adjacent the projections acting to oppose the magnetic field produced by the current flow through said winding means whereby a force is developed tending to cause separation of said trailing faces thereby assisting the relative movement of the members to reduce said gap between said attraction faces.