Improvement in Automatic Telephone Exchange Systems.

摘要

18,648. Western Electric Co., [Western Electric Co.]. Aug. 18. Order apparatus. - In telephone systems in which calls from an automatic or semi-automatic exchange are extended to a manual exchange, the number of the desired subscriber is indicated visually to the manual operator by means of a number indicator comprising a switching-device for each digit, each device controlling the circuit of ten indicating-lamps. Each switch consists of a clutch-driven spindle carrying a number of cams which press the contact-springs shown in the upper part of the Figure against their upper and lower contacts in succession, thereby closing a circuit through one of the ten lamps, according to the position in which the spindle is arrested. The clutch-magnet 401 of the ' thousands ' switch is first energized, and, as its spindle rotates, a cam 413 intermittently earths a lead 217, thereby operating impulsecounting relay apparatus at the semi-automatic exchange. When the number of impulses received by the relay apparatus corresponds to the value of the depressed key, the clutchmagnet 401 is de - energized, and the clutchmagnet 402 of the ' hundreds ' switch energized in its place. The ' hundreds,' ' tens,' and ' units ' switches are operated in a similar manner, the number of the subscriber wanted being finally indicated by the lighting of a lamp in each digit indicator. The numerical indicator may be connected to trunks handling incoming calls by means of a call-finder.