Patent GB-561148-A (GB)
Title: Printing telegraph system
IPC: H01H67/26
Filed: 1942-10-02
Abstract: 561,148. Telegraphy. TELETYPE CORPORATION. Oct. 2, 1942, No. 13845. Convention date, Sept. 20, 1941. [Class 40 (iii)] [Also in Group VIII] A printing telegraph system comprises a transmitting distributer which may be selectively associated with a plurality of communication channels, and means (e.g. permutation members controlled by a perforated strip) dually operable (1) to select a switching lever to control the selection of the desired communication channel, and (2) to control the selective operation of the distributer to transmit signals over the selected channel. The invention is described as applied to a system having a printer-reperforator combined with a perforated-tape sensing device controlling two transmitting distributers, one operated directly and the other after a certain delay ; the second distributer is associated with switching apparatus, controlled by switching perforations in the tape, to select the line to which the message is then transmitted. Printer-reperforator. This resembles closely the instrument described in Specification 540,612, the notched code bars 27, Fig. 2, being set selectively by a selector mechanism of the sword and T-lever type described in Specification 245,149, [Class 40 (iii)]. The selected pullbar 26 is caused by the printing bail 37 to operate the corresponding type-bar to print the selected character. The code bars 27, through levers 46, 52, 56 operate corresponding interponents 58 of the perforating mechanism, the selected punches 66 being operated by the cam-controlled cradle 62. The punch block 67' has a die plate 72 to produce a " lidded " aperture in the tape, as in Specification 540,612, by a shearing, rather than a blanking, operation. Spring-operated levers 77, pivoted to the die plate, depress the stripper or ejector pins 74 at the end of each cycle to eject the " lids " from the die plate. A ratchet-operated feed-wheel 81 is supported within the punch block, the tape being fed over guide 139 from a pre-punch unit 91 which perforates a feed hole in the tape, a second feed-wheel being arranged between the unit 91 and the punch block, thereby making it possible to vary the position of the code holes with respect to the feed holes, and to maintain a tape loop between the units, thus reducing the drag on the tape at the perforating position. In order that the perforator may be operated independently of received code signals, the selector cam assembly may be released manually, instead of by the usual " start " impulse. Sensing unit of the automatic transmitter. The sensing unit is of the pivoted or travelling type described in Specification 531,337 and is mounted close to.the perforator so that it can sense the tape immediately it leaves the punch block but permits of the formation of a tape loop between the perforator and the transmitter if the former works more quickly than the latter. The tape 190 passes over a perforated plate 171, mounted on a pivoted frame movable to and from the perforator according to the relative speed of working. The frame has a series of five sensing pins 175 mounted on corresponding Y-levers 182 oscillated about shaft 166 by springs 189 when permitted by cams on the cam drum 196. The Y-levers control two separate transmitting distributers, one used, e.g. for monitoring all messages and the other used to transmit to a selected channel only. First, or monitoring, transmitting distributer. The passage of a sensing pin 175 through a perforation permits the corresponding Y-lever 182 to move counter-clockwise, a projection 289 on lever 182 permitting the closure of the corresponding contact 288. The contacts 288 are connected respectively in series with corresponding contacts 287 closed in turn by the cams 271 of a mechanical distributer, so that signals are transmitted corresponding to the closed contacts 288, i.e. to the perforations in the tape. Second transmitting distributer. The setting of the Y-levers 182 is also transferred by corresponding T-levers 311 (carried by a camoscillated frame 306) to sliding bars 316 controlling catches 322, which, when released, permit cams 326 to allow levers 337 of a second cam-distributer to close selected contacts, in accordance with the setting.of the Y-levers, to transmit signals to a channel selected as described in the next paragraph. During the transmission of the code signals of one character, the Y-levers may be set in accordance with the following character, thus providing complete overlap. Selection of channel over which message is transmitted, or other function. Associated with the sliding bars 316 (five in number for a five-unit code) are a plurality of function levers 351 co-operating with notches on the upper and lower sides of bars 316, so that any one lever 351 may be selected by a particular setting of the bars 316 by the perforations in the tape. The levers 351 control contacts 354, Fig. 7, which select the channel to receive the subsequent message or perform some other function. The levers are normally held non-responsive to the permutable settings of the code bars 316, but are rendered selectively responsive to the setting of the code bars by a predetermined operation of the code bars, produced by a particular code combination, e.g. one shift signal such as figures, and are subsequently rendered non-selective by a different combination, e.g. the other shift signal. Selection of desired channel. Contacts 354, Fig. 7, selected by the function levers 351, control relays 386, 387, 388, which look up so 'as to be independent of contacts 354 but dependent on' the contacts of similar relays so that when one of the relays 386, 387, 388 is energized, the others cannot be. These relays control the connection of circuit L from the transmitting distributer to one or other of the channels 389, 390, 391, and are de-energized at the end of the message by transmitting the code combination to open the contact UCZ.