GB595471A - Improvement in self-interrupting electromagnetic vibrator - Google Patents

Abstract

595,471. Electromagnetic interrupters. PLESSEY CO., Ltd. April 24, 1945, No. 10254. Convention date, May 26, 1944. [Class 38(v)] In an electromagnetic vibrator, t h e movable driver contact 36 is mounted on an auxiliary reed 37 which is separately formed and attached to one side of the main reed 26. In the form shown, the reed 26 carries an armature 39 which is adapted, when the coil 12 is energised, to engage the reed 37 at 40 after a predetermined time delay and move it to the left also, so that the normally closed contacts 36, 41 are opened and the coil deenergised. The reed 37 and contact carriers 31, 32 are attached to reed 26 by rivets 33 or by welding. Contacts 34, 35 on springs 31, 32 co-operate with relatively fixed contacts 24, 25 to interrupt and rectify the currents in the primary and secondary windings, respectively, of a transformer (not shown). In a modification, Figs. 4 and 5 (not shown), the auxiliary reed 36 is not engaged by the armature 39 and has a natural frequency slightly lower than that of the main reed so as to ensure correct sequential operation of the main and driver contacts. In a further modification, Figs. 6 and 7 (not shown), a stop extends along the auxiliary reed to cause positive actuation of the driver contact on deflection of the main reed in one direction, the auxiliary reed being free to return by itself.