GB282175A - Improvements in electric bell indicator systems - Google Patents

Abstract

282,175. Parsons, I. H. Sept. 22, 1926. Indicating origin of call to servants and other attendants.-In an electric bell indicator system for use in buildings, such as hotels, wherein the operation of a press button switch releases an attendant's indicator and rings a bell, a delay acting switch is released simultaneously to operate an alarm unless the indicator is reset within a predetermined time period. In the system shown in Fig. 1, operation of a push I, energizes the corresponding indicator release magnet G and rings the bell J. The electromagnet B of clock-driven switch C is simultaneously energized to release the arm C' which closes at the contacts D, the circuit of a supervisor's bell K, unless reset by the indicator replacement rod F within a predetermined time period. An indicator may be used instead of the bell K. Fig. 3 shows a form of delay acting switch. The arm C<1> which operates the alarm contact D, D<1>, is mounted on the spindle C27 and held against the action of a driving spring C2 by the armature B1 of the electromagnet B. The latch B2 of the armature engages a lever C21 pivoted to the arm C1 and having a limited movement provided by a pin C23 co-operating with a slot C24 in the arm. The lever C21 provides for the rapid disengagement of the switch arm C1 and facilitates replacement. Movement of the arm is controlled by an escapement or fly mechanism through a train of wheels C29, C30, C31.