GB345293A - Improvements in or relating to telegraphic and wireless transmission systems - Google Patents

Abstract

345,293. Type-printing telegraphs. SOC. ANON. BREVETTI ITALIANI ESTERI S.A.B.I.E., 47, Via Bertola, Turin, Italy. Dec. 12, 1929, No. 38164. Convention date, Dec. 14, 1928. [Class 100 (iv).] Carriage-returning mechanism ; letter-spacing mechanism.-In a telegraphic and wireless transmission system the signals consist of combinations of two different frequencies selectively operating tuned electromechanical relays 100<1> .. 100<9> which prepare printing circuits at the contacts 104I, 104II, .. of a recombinator 103. The arms 105, 106 of the recombinator are rotated synchronously with a type-wheel A mounted in a printing frame 140, the leaf passing under the hammer of a printing relay 135 corresponding to the letter represented by the two contacts engaged by the arms 105, 106. When a printing circuit has been prepared and the arms 105, 106 engage the appropriate contacts, the hammer of the relay 135 strikes the leaf of the type-wheel A. At the same time an electromagnetic coupling 138 is energized causing a gear wheel 185 to be clutched to a screw-threaded shaft 139 which advances the printing frame for the next letter. A pawl 161 effects through relays the declutching of the shaft 139, and opens the circuit of the printing relay. When the carrier reaches the end of a line, it engages a contact 155, effecting the energization of relay 157 to hold the pawl 161 whilst the carrier is returned to its initial position at the commencement of a line by a spring (not shown). Simultaneously a relay 164, energized in parallel with the relay 157, actuates a ratchet and pawl 166 to step the paper carrier 168 for a fresh line. When the printer frame reaches its initial position, it moves a spring member 159 to break the circuit of the relays 157, 164.