Abstract: In an electromagnetic drive unit including;a nearly E-shaped yoke having first and second concentric circular arc shaped side yokes respectively inside and outside an arc-shaped center yoke,a first arc-shaped permanent magnet fixed to said first side yoke so as to form a first magnetic gap inside said center yoke,a second arc-shaped permanent magnet fixed to said second side yoke so as to form a second magnetic gap outside said center yoke, anda movable coil member disposed in said magnetic gaps, said first and second permanent magnets are so provided with anisotropy in directions which are different each other that the magnetic flux density in said first magnetic gap will be nearly equal to that in said second magnetic gap.

Abstract: An actuator for use in a pickup device for a video disk plunger having a cylindrical yoke made of a soft magnetic material, a pair of tubular solenoid coils disposed in said yoke such that the same polarity appears at adjacent portions thereof, and a movable element disposed axially movably inside of the tubular solenoid coils, the movable element having an axially magnetized permanent magnet and pole shoes attached to both ends of the permanent magnet. Dampers made of a resilient material such as a butyl rubber are secured to both ends of the yoke. The dampers support projections projected from both ends of the movable element such that the projections project axially outwardly of the dampers. A permanent magnet for magnetically attracting a stylus is secured to the outer end of one of the projections.

Abstract: An actuator driven by D.C. power suitable for use in actuating automobile door locking device. The actuator has a yoke apparatus defining a space, two annular solenoid coils supported and received by the yoke apparatus and adapted to be energized simultaneously such that poles of the same polarity appear at the adjacent ends of the coils, and moving means reciprocatably disposed in the space of the yoke apparatus. The moving means includes an axially magnetized permanent magnet carried by a shaft and a pair of magnetic members attached to both axial ends of the permanent magnet.

Abstract: Electrical contacts are produced by processes comprising (1) forming on a metallic body a first layer of low melting metal(s) and (2) forming on the first layer a second layer of high melting metal(s). The thus produced contacts possess prolonged life, approximately 10 times that of conventional contacts when they are operated as working contact.