GB1192779A - Improvements in or relating to Electric Interrupters - Google Patents

Abstract

1,192,779. Electric interrupters. SWFSPEZIALFABRIK FœR AUTOZUBEHÍR GUSTAV RAU G.m.b.H. 29 Dec., 1967 [4 Feb., 1967], No. 58983/67. Heading H1N. To maintain the frequency of an interrupter constant on rise in energizing current through coil 19 an auxiliary armature 24 is provided which is attracted to polepiece 21 when the current exceeds a predetermined value and thus shunts some of the increased flux away from the contact actuating armature 23. The armature 23 is resiliently mounted on a polepiece 20 and carries a contact 30 co-operating with a fixed contact 31. The auxiliary armature 24 is mounted on a leaf spring 26 and is normally biased against a backstop 27. The armatures 23, 24 move in mutually perpendicular planes. Armature 23 is normally held so that contacts 30, 31 engage by a hot wire 35 connected between armature extension 33 and adjustable arm 37 and acting against a return spring 32. A second contact carrying armature 22 is spring mounted on polepiece 20 and its contacts are normally open. The interrupter is used as a flasher for vehicle direction indicators. When either the right or left indicators are energized separately, current flows through interrupter core 18, armature 23, contacts 30, 31, coil 18 to the indicators. Energization of coil 18 attracts armature 22 causing its contacts to close and complete a circuit through the hot wire 35. On rise in temperature of hot wire 35, spring 32 retracts armature 23 from the polepiece 21, thereby de-energizing the interrupter and the direction indicators. When cool, hot wire 35 returns armature 23 to its initial position and the cycle is repeated. If both left and right indicators are flashed together for warning purposes the current through coil 18 will be doubled (the indicators are in parallel), thereby increasing the attraction of armature 23 and tending to reduce its frequency. However, auxiliary armature 24 is attracted by the increased current and shunts sufficient flux from armature 23 to ensure the frequency remains constant. Several auxiliary armatures may be provided to stabilize the frequency over a wider current range.