Patent GB-305075-A (GB)
Title: Improvements in and relating to telegraphic receiving and transmitting apparatus
IPC: H04L25/04
Filed: 1927-10-29
Abstract: 305,075. Marks, E. C. R., (Horn, J. A. L.). Oct. 29, 1927. Automatic transmitters; type - printing telegraphs; restoring imperfect signals.-In a telegraphic receiving, correcting, storing, and retransmitting apparatus two sets of storage pins 1, Fig. 1, rotate about a common axis and the pins of each set are actuated axially in one direction only by a single pin-setting member under the control of incoming signals. In addition to retransmission, or alternatively, the received signals may be recorded by a Wheatstone perforated tape or by a printing-machine. The sets of storage pins respectively frictionally engage parallel marking and spacing wheels 2, 21 so as to slide axially and parallel to the common axis of the wheels. The pin-setting member, which reciprocates coaxially with the wheels, has a crank 10 which alternately engages marking and spacing pins, and a diamond-shaped head 11 on the crank simultaneously coacts with the respective crown teeth on corrector wheels 3 attached to each of the wheels 2, 21 to correct any distortion of the received signals before recording or transmitting. The wheels are driven by an electric motor, not shown, through a shaft 28 and gearing 24 - - 27. A friction clutch 51 on the shaft Drives an extension 29, which rotates in halfrevolutions through the co-operation of stop 31 - with a tongue 30 of the relay receiving signals, not shown. The clutch is supplemented, when rotation has begun, by friction between a disc 54<1> and the surface of fraction wheel 52. the milled surface of which is removed in two diametrically opposite places so as not to engage in the position of rest. A cam 16 on the extension reciprocates the pin-setting member thrugh a spring-mounted lever 14 and a pin wheel 37 engages a star wheel 36 to transmit an intermittent rotary movement to a friction driving-plate 18 to rotate the pinsetting member to compensate the rotation imparted to the pin-setting member by the correcting wheels. The pin wheel is adjusted relatively to the cam by the grub screw and scale shown to provide the correct compensatory rotation to the pin-setting member. Repeating relay, Fig. 5. Alternately arranged cams 45, mounted on a shaft 54 driven from the driving shaft by gears 67, 68, operate levers 47 having projections 48 which bear upon bosses 20 on the storage pins. When a pin is displaced the engaging lever drops and forward movement produced by its cam actuates a repeater switch lever 49. Synchronous movements.-When the apparatus is running synchronously with the incoming signals, movement of the pin-setting member and its friction driving-plate is exactly compensated as described above. Forward or backward motion of the plate causes a lever 44, Fig. 6, coacting with raised portions 43 on the plate, automatically to close or open electric contacts 56, 57 for inserting resistances E, A in the field circuit and armature of the driving motor to increase or reduce the speed to secure synchronism. A master contact 58 actuated by a double cam 59 on the driv. ing-shaft extension ensures that the synchronizing device shall operate only momentarily. Alternatively the lever actuates the contacts of two electro-magnets, the armature of which control pawls mounted on a lever reciprocated by an eccentric on the cam shaft of the repeating- mechanism and the pawls actuate ratchet wheels in opposite directions to control a resistance in the field circuit of the motor (Fig. 8. not shown).