GB228610A - Improvements in or relating to telegraphic transmitting apparatus - Google Patents

Abstract

228,610. Creed & Co., Ltd., and Creed, F. G. Nov. 5, 1923. Type - printing tele. graphs.-Relates to startstop keyboard transmitters in which the operation of a key corresponding to a letter or space effects the setting of a series of longitudinally - movable combination bars in such relative positions as to enable the transmission to line of sequences of impulses corresponding to the letter &c. according to a five or other multiple-unit code. The bars are normally held by a stop against movement by springs, and the Operation of a key locks one or more of the bars, whereupon a motor removes the stop to allow the unlocked bars to move and, after the transmission of the impulses, returns the stop and the bars to normal position. Selection of current sequences. Each letter key n or space key n<1>, n<2> is carried by a horizontal bar m mounted in guides t, t<1> and fixed to a vertical rod o mounted in a guide t<2>, and each rod o is pivoted to a lever r controlled by a spring s to hold the key normally raised. Depression of a key lowers its bar m on to the combination bars a to lock one or more of these against movement by its spring c upon the subsequent removal of a stop lever d. The movement of the bars operates corresponding contact levers e<1> - - e<5> to move their contacts from a fixed contact g, connected to negative battery, to a fixed contact h, connected to positive battery. Start-stop device. A sleeve x loosely mounted on a motor-driven spindle v carries a spring- actuated pawl 6 normally held out of engagement with a ratchet w on the spindle by an arm 7 of a spring-controlled bell-crank A. Upon depression of a key the corresponding rod o operates through a bell-crank B, a link 12, and a bell-crank C to lift a bar 8 provided with a shoulder 8<a> engaging beneath the arm 7<a> of the bell-crank A which is thus operated to release the pawl 6. This pawl thereupon engages the ratchet w and the sleeve x is rotated. During such rotation an eccentric portion of the sleeve x engages the bar 8 and the bell-crank A is released in readiness to re-engage the pawl 6 to stop the rotation upon completion of one revolution. Transmission to line. The contacts on the levers el - - e<5> and the contacts h, g are connected as shown in Fig. 12 to contacts 1 - - 5, P, and N respectively arranged as shown in Fig. 9 around a contact y<2> on a stationary plate @, and this contact y<2> is connected to line. The sleeve x is provided with a spindle extension x<1> carrying a central contact y<1> bearing against the contact y<2> and a brush contact y adapted to sweep over the contacts P, 1 - - 5, and N, thus sending to line a + starting impulse, a sequence of five signal impulses, and a - stopping impulse. The stop lever d for releasing and returning the bars a is operated by engagement of a roller on its arm d<1> with a cam groove 14 on the sleeve x.