Patent GB-150008-A (GB)
Title: Improvements in or relating to wireless telegraphy or other wireless control systems
IPC: H04K1/00
Filed: 1919-03-07
Abstract: 150,008. Comparri Wireless Control Syndicate, and Compare, M. March 7, 1919. Type-printing telegraphs.-In a wireless type-printing telegraph, each letter is represented by a combination of two or more trains of impulses of different group frequency transmitted in quick succession and received by resonance relays, such as described in Specifications 22807/14 and 134,297. To ensure secrecy, a commutator switch may be associated with both transmitter and receiver to change the code representation of each letter or control at will. In the system, each letter is represented by a combination of two group frequencies out of the eight frequencies represented by the interrupters R1 - - R8, Fig. 1, which are connected through the secrecy commutators C1 - - C8 to two sets of contacts B1 - - B6 and C2<SP>1> - - C<1>8 arranged on opposite sides of the keys K1 - - K27. Assuming that the interrupters R1 - - Rg are connected to the commutators C1 - - C8 respectively, the interrupters R1 - - R6 are connected to the sets of contacts B1 - - B, as shown, and the single contacts C2<SP>1> - - C<1>8 are connected to interrupters R2 - - R8 as indicated by the numbers above each of these contacts. The depression of a key K1, say, completes the circuit of the relay R controlling the wireless transmitter first through a contact B, and interrupter R, and then through contact C2<SP>1> and interrupter R2. At the receiving-station, Fig. 2, the received impulses are repeated by a relay R to a series of eight resonance relays O1 - - 0, tuned to the frequencies of the interrupters R1 - - R8, Fig. 1. The contacts of the relays O1 - - O8 are connected through secrecy commutators C1 - - C8 to a series of magnets M1 - - M6 and to a series of spring contacts F controlled by these magnets. The contacts F co-operate with helically-arranged contacts on a rotating drum R<1> carrying the type-wheel. The magnet M1 controlled by relay O1 carries seven contacts F controlled by relays O2 - - O8, the numerical arrangement of the magnets M and contacts F corresponding to the connexions of the contacts B1 - - B6 and C2<SP>1> - - C<1>8, Fig. 1, to the interrupters R, - - R8. Thus, when the key K1, Fig. 1, is depressed, the relays O1, O2 are operated in succession; relays O1 energizes magnet M1, which locks up and brings its group of springs F into engagement with the drum R11 and relay O2 connects battery to the spring F2 so that when the contact on the drum R, engages this spring a circuit is closed to operate the printing-magnet P and thus print from the type-wheel the letter then in the printing position. Construction of keyboard transmitter. The keys K, Figs. 3 and 5, are normally locked by a transverse bar X, which, together with a bar B carrying the set of contacts B1 - - B6, and a bar C, carrying the contacts C2<SP>1> - - C<1>8, is mounted on side bars S so as to be reciprocated by cam wheels W1 geared to the interrupters R1 - - R8. When the notch W3 in the cam engages bar S, the locking-bar X is raised so that a key K can be depressed so that its spring G<1>, Fig. 5, engages one of the contacts B1 - - B6 and one of the contacts C2<SP>1> - - C<1>8. After half a revolution of the cam, the contacts B1 &c. are lowered and one of the upper contacts C2<SP>1> &c. engages the spring G<1>. In a modified construction, the keys are in the form of piano keys, and the bars S are replaced by double-armed levers controlled by an eccentric. Modified receiving-apparatus. The roller R', Fig. 2, with contact studs thereon may be replaced by a metal roller covered with paper having perforations at points corresponding to the contact studs. Contact is made by a finger F, Fig. 13, having a spring-pressed ball L projecting through a hole therein. Specification 140,864, [Class 38 (v), Electric switches &c.], is also referred to.