GB1418606A - Plunger electromagnet - Google Patents

Abstract

1418606 Electromagnets VSESOJUZNY NAUCHNO - ISSLEDOVATELSKY INSTITUT TELEVIDENIYA I RADIOVESCHANIYA 6 May 1974 19772/74 Heading H1P A plunger electromagnet operating mechanism comprises (Fig. 1) a housing of ferromagnetic material enclosing main and auxiliary electromagnets respectively comprising a working armature 2 within a winding 3 and an auxiliary armature 4 actuated by a winding 5 over an airgap 6 for axial motion therein. Armature 4 is a hollow cylinder coaxial with armature 2 with flange 7 abutting spring 8 urging it towards the armature 2, which operates push and pull drive rods 9, 10; the former having a resilient shock absorber 11. The end face of armature 2 adjacent the armature 4 has a truncated conical steel stop 12 and the opposite end face may be conical engaging a complementary recess of a magnet core. A locking means 13 is provided comprising a hollow non-magnetic cylinder with plural radial holes 14 at the end adjacent the armature 2 containing balls 15. Armature 2 is freely slidable within the locking means 13 and armature 4 is similarly slidable over its outer surface. With armature 2 within the locking means the external loading is applied to the walls of the radial holes thus releasing armature 4 for movement. The winding 3 is carried by a spool having ferromagnetic faces 16, 17 interconnected by a non-magnetic insert 18; and threaded to ferromagnetic housing 1 at 19. Winding 5 is carried by a ferromagnetic spool 20 secured to the housing by rolling. A manual release may be provided for the working armature. In operation, a current pulse in winding 3 moves armature 2 to abut the core of face 16, and armature 4 is moved by spring 8 to follow it, and presses balls 15 into the holes 14 of locking means 13. On termination of the pulse, armature 2 and stop 12 abut the balls and are retained in the drawn-in position. A current pulse in winding 5 causes armature 4 to override spring 8 and retract over the cylinder of locking means 13 to release the balls 15 to be impelled outwardly by stop 12, so that armature 2 resumes its initial position before armature 4 has completed its travel (Fig. 2). The pulse current may be derived from a capacitor charged between operating pulses. The device may operate brakes, spring loaded levers, or pressure rollers of tape recorders. The end face of the working armature may be flat.