Improvements relating to Drop Signals or Annunciators for Central Telephone Stations and so forth

摘要

28,629. Birnbaum, I. B. Dec. 28. Indicators or annunciators. - A ' drop ' at a central telephone station, when released, closes a bell circuit by a sliding contact. When a call is given, the armature b is attracted to the electromagnet a and the drop f falls. The tail-piece h makes sliding contact with the spring i. This spring i is supported by a screw k insulated upon the front plate e, and is connected to one end of the bell circuit, the other end of which is connected to the front plate e.