Patent GB-844262-A (GB)
Title: Improvements in or relating to printing telegraph apparatus
Inventor: HANDLEY JOHN
IPC: H04L13/08
Filed: 1957-08-09
Abstract: 844,262. Printing telegraph transmitters. CREED & CO. Ltd. Aug. 8, 1958 [Aug. 9, 1957], No. 27676/59. Divided out of 844,261. Class 40(3). In a telegraph keyboard transmitter, a storage device is provided between the code bars which are set by the keys and the combination bars which control the transmitter contact to permit the keys to be operated at faster than cadence speed. The storage device is in the form of a drum having a plurality of rows of radially displaceable pins, a code combination being stored on each row. The arrangement is characterized by the use of an assembly of members for positioning the pins in a row consequent upon actuation of a key which is rotated in a first direction with respect to the drum after each operation to bring it to the position to operate the next row of pins. The stored code combinations are then read out with the aid of a stationary assembly of combination bars, the drum. and positioning members being rotated in the opposite direction through one row under the control of the transmission timing shaft consequent upon transmission of each code combination. Provision is made whereby the keyboard is locked against further operation if code combinations are stored so much faster than they are read out that all the available pin rows are occupied. Signal storage arrangement. The signal elements are stored on a drum 70, Figs. 1 and 2, in twelve circumferential rows, each comprising five radially movable pins 71 frictionally held by intervening spacers 72 and end springs 73. The pins are set by five pusher rods 77-81 disposed for axial movement in slots in a rotatably mounted housing 87 and carrying at their ends discs 181- 185 which are engaged and selectively moved by forked members 201, Fig. 5, rotated by crank pins 195-199 in engagement with the ends of the code bars 4-5. A cam 183, Fig. 9, driven by a ratchet 184 on a continuously rotated shaft 182 when a lever 187 controlled by the trip bar is in the position shown and the cam in this position operates a rod 194 to return the code bars 4-5 to their normal position and also a rod 193 to return the cranks 195-199 to their normal positions. The trip bar in its movement to the right also rotates a crank 203 controlling a link 92 which brings the head of a pivoted pawl 93 out of engagement with projections 204 on the pin drum housing to allow the housing 87 to be rotated clockwise until the tail of the pawl engages another projection 204, and when the crank 203 is moved back at the end revolution of the cam 183, the link 92 moves back so that the head of the pawl engages the next projection 204 on the housing of the storage drum 70. When a signal has been stored on a row of pins, a finger 96 on the pusher housing allows a rod 206 to move upwardly so that a detent 207 is moved by spring 209 out of engagement with a detent 210 so that the transmitter shaft 27 is set into rotation, and the combination levers 211-215 selectively set by the pins 71 and latched by bail 28 are sensed by five three-armed levers 97-101. Towards the end of a revolution of the shaft 27 a restoring bail 216 raises all the levers 211-215 to their upper positions and a pawl member actuated by a cam on the shaft 27 steps the drum 70 to bring the next row of pins 71 to the operative position with respect to the ends of the levers 211-215. The pins 71 which have been moved outwardly are reset by a curved flange 219. If the number of combinations set up on the rows of pins approaches the capacity of the drum, the pin 96 on the pusher housing operates a lever 225 to engage a pawl 227 mounted on the locking bar of the keyboard, so that further key operation is prevented until some of the stored signals have been transmitted and the locking lever 225 restored by its spring 226.