GB547628A - Improvements in and relating to telegraphic transmission apparatus - Google Patents

Abstract

547,628. Telegraphy. HUHNE, H. PAUL-, PAINTON, J. E., and LONG, E. W., [Representatives of PAINTON, P. R.]. Nov. 29, 1940, No. 17078. [Class 40 (iii)] In a keyboard transmitter, the depression of a key connects the driving mechanism to a code roller which is oscillated to transmit the code signals. The code roller is driven through sun- and-planet gearing against the action of a spring, which returns the roller to its normal position when the code signal has been transmitted. The code drum 1 may have a series of discs 2 rigid therewith, each disc having two sets of code contacts 3, 3a. One or other of these sets of contacts is engaged by springs 33 or 32 carried by a pivoted block 34, the position of which is determined by a shift key 63 through link 34a. All the springs 32 or 33 engage the corresponding code discs, the particular code transmitted being selected by the depression of a character key 15, which moves upwards a corresponding switch-bar 18 so that a spring 21 a moves from an insulating part 21 to a conducting part. When the code drum rotates, the circuit is thus closed through the code disc, a spring 32 or 33, wire 61, spring 21a, and the conducting part of the selected switch-bar 18. The bar 18 is retained in its raised position by a notch 23 engaging a member 19 and by moving lever 44, 39, allows a spring to press lever 11 so that its tooth 10 tends to engage teeth 9 on the outside of the sun-and-planet gear 8. This movement is, however, prevented by a lever 49, 47 until the depressed character key is released, whereupon the tooth 10 arrests the outer gear of the sun-andplanet, causing the planets to rotate the code drum. The lever 47, 49 also prevents a second key being depressed until the code signal corresponding to the first key has been sent. After the signal has been transmitted, a pin 52 on the selected code disc engages the upper end of the selected switch bar 18 and restores it to normal. This results in tooth 10 being withdrawn from the sun-and-planet gear, and the code drum is returned to its normal position by a spring.