Multiple latching relay reset mechanism for telephone exchanges - uses coil operated reset bar to reset relay even under faulty latch condition

摘要

The multiple latched relay consists typically of twelve parallel electromagnetic latches (1) operating in parallel with one permanent magnet (5) and a common magnetic yoke (6) with twelve indenpendent pole pairs (2, 3) and twelve associated spring (10) mounted latching elements (9). A latched element (9) remains latched due to the permanent magnetic field, and is released by a current pulse through a coil (7) would round one of the poles (2) associated with that latching element (1). This reduces the field momentarily and the spring (10) ensures the release of the latch. Certain fault conditions, in particular if two coils (7) are actuated simultaneously can prevent this release, and an additional mechanism consisting of a coil (12) operated release bar (15) which mechanically releases the latches, is incorporated for this reason. A current interruption switch (17) is also incorporated to prevent coil (7) overheating under faulty conditions.