Improvements in Selective 'Signalling Systems for Party Lines'.

摘要

10,807. Western Electric Co., [Woodward, F. T., acting for Western Electric Co.]. May 1. Party - line systems and apparatus.-In a step-by-step selective signalling system, in which the selecting-impulses can be sent from either end of the line, a polarized relay 30 is provided in the bridge across the lines at each station, arranged to cut part of a resistance 31 in or out of circuit to adjust the resistance of the bridge so that it receives the same strength of current from whichever end of the line the impulses are sent, the two impulse-sending stations being arranged to send impulses of opposite polarity. The system is of the kind in which a ratchet-wheel 18 is rotated by means of stepping and holding pawls 21, 22 controlled by quick and slow acting magnets 19, 20.