Patent GB-399242-A (GB)
Title: Improvements in or relating to keyboard controlled current impulse transmitters
IPC: H04L17/06
Filed: 1932-04-21
Abstract: 399,242. Typeprinting telegraphy. FULD & CO. TELEPHON - UND TELEGRAPHENWERKE AKT.-GES., H., 136, Mainzerlandstrasse, Frankfort - on - Main, Germany. April 21, 1932, No. 11498. Convention date, June 25, 1931. Addition to 389,999. [Class 40 (iii).] The parent Specification relates to a keyboard transmitter in which the impulses are sequentially transmitted by a contact member actuated by a group of movable cams selectively set under control of the keys and in which the cams in their normal or unactuated position are subjected to a stored force released by members controlled by the actuation of a character key to move one or more of the cams to their operative positions. According to the present invention, the bars actuated by the keys and controlling the cams move under spring pressure to their actuated positions when liberated by a key lever and are returned to their normal positions against the action of springs by the device which provides the stored force for the cams. The key levers 54 are formed with notches and projections co-operating with notches in the selecting bars 57I .. 57V. On depression of a key the bars 57I . . 57V ate selectively prepared for movement laterally when freed by an auxiliary operation effected during the initial stage of the key movement. On the depression of a key a bar 59 rotatable on an axis 60 is tilted and a pivoted finger 65 rocks a latch member 64 pivoted on a shaft 77 out of engagement with the bars 57, 58, the permutation bars moving selectively to the right followed by movement of the release bar 58 during the final stage of the key movement. The finger 65 in its depressed position registers with an opening in the latch member 64 so that the latter is released for return by a spring 78 to latch the bars 57, 58 when the latter are returned to their normal or unactuated positions. The bar 58 rocks a pivoted lever 83, the free ends of which normally engage projections 85 on a spring-controlled detent having teeth 89 which mesh with teeth 90 on the shaft 88 of a drum 87 through which the transmitter 100 is clutched to a gear wheel 91 of the auxiliary driving device. The bars 57I .. 57V control pivoted members 71 co-operating with projections 76 on discs 106 which are rocked to release pins 95 moved under the action of springs 96 to position the cams 93 selectively with respect to the transmitting contact 92, as described in the parent Specification. Shortly after the commencement of the rotation of the drum 87, a projection 97 fixed relative to the shaft 88 engages a pivoted member 98 carrying a laterally extending bar 103 which, on being rocked in the clockwise direction, returns the release bar 58 and the bars 57I .. 57V, which had been moved to the right, to their normal position against the action of the springs 63, where they are latched by the member 64, which is returned upwardly independent of the upward movement of the bar 59 by the release of the key lever. The latch member 64 may be provided with a slide or shutter over its opening so that the latch member 64 is not liberated for upward movement except by the release of the key lever, thus allowing a signal to be repeated whilst the key is held depressed.