Abstract: In the magnetic chuck disclosed herein, a pair of elongate pole members are arranged to provide magnetic contact with a workpiece along parallel lines and thus are somewhat in the nature of rails. Preferably, the ends of the poles are segmented and provide for height adjustment to accommodate workpieces which are not entirely flat. The pole members extend along the sides of an elongate base plate with a space therebetween. Interposed between each pole member and the base member is a relatively thin layer of permanent magnetic material which resists de-magnetation. A switchable permeable magnet is provided between the pole members above the base plate and this latter permanent magnet is surrounded by a coil which allows the polarity of its magnetism to be switched so that it either aids or opposes the thin magnetic layer in polarizing the pole ends.

Abstract: A screw-and-nut mechanism with a ball recirculation channel comprising bent, tubular inlet and outlet elements connected to each other by a connecting means, the tubular elements being engaged in a bore of the nut member in such a way as to emerge at the bottom of the thread, and the connecting means being embedded in an overmolding of the nut member.