US PATENT SUBCLASS 178 / 64
.~ Coil transformer
Current as of: June, 1999
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DEFINITION
Classification: 178/64
(under subclass 2) Systems for transmitting messages by induced currents having an induction-coil or transformer, usually with its primary in a local circuit, with the transmitter and its secondary in the main line; also includes systems utilizing induction-coils or transformers between sections of the main line.
SEE OR SEARCH THIS CLASS, SUBCLASS:
43, for systems transmitting messages through appreciable space by induction between lines, coils, or other elements.
47, for harmonic or tone telegraphy employing circuit interrupting transmitters or vibrating receivers.
49, for use of transformer or induction-coil in superposed-current signaling.
SEE OR SEARCH CLASS
336, Inductor Device, appropriate subclasses for the structure of transformers and inductive reactors. 379, Telephonic Communications,
37+, for protective signalling over a telephone line, subclasses 90+ for the combination of a diverse system of current transmission and a telephone system, subclasses 108+ for alternative use of a telephone or a telegraph over the same line.
