Patent GB-667665-A (GB)
Title: Signal transmitting apparatus embodying coding wheels
IPC: H04L9/22
Filed: 1948-05-28
Abstract: 667,665. Type-printing telegraphy. OLIVETTI & CIE, SOC. PER AZIONI, ING. C. May 28, 1948 [May 30, 1947], No. 14535/48. Class 40 (iii). [Also in Group XV] In a signal transmitting and receiving arrangement including a ciphering device comprising a set of wheels associated with means for controlling a mechanism for translating a code combination of signal elements into a ciphered code combination and vice versa, each wheel being provided with a predetermined arrangement of pins, a driving device for the wheels comprises an advancing member associated with each cipher wheel and disposed in an operative or inoperative position with respect to its wheel by means dependent on the position of the pins on the succeeding cipher wheel. In the combined transmitter and receiver shown, the ciphering wheels are toothed discs 10 carrying the pins 9 and having markings visible through an aperture in a cover member 57. Transmitting-operation. When the end 8 of a pivoted lever 6 is in contact with a pin 9, a latch 4 pivoted on an extension of a code bar 1 allows an associated operating lever 13 controlled by a cam 16 to close contacts 18 when the bar 1 is not moved on depression of a key lever 2. If the bar 1 is moved to the right, the latch 4 obstructs the end 17 of the lever 13 which is unable to close the contacts 18. If the end 8 is not in engagement with a pin 9, the lever 6 is rocked clockwise against a stop 20 so that the latch 4 is opposite the end 17 of the lever 13 when the bar 1 is not moved and is rocked clear of the end 17 when the bar 1 is moved to the right. Receiving-operation. In the receiver of the transmitting station or of the distant receiving station, the armature 22 of the magnet 21 has an extension with an aperture 27 associated with an expanded head 28 on one arm of a lever 29 having a second arm with a pin-and-slot connection with a lever 33 having an end 35 associated with the pins 9 on the wheel 10. The lever 29 is carried on a lever 31 having an extension 42 associated with a shoulder 41 on a bell-crank 38 linked by a spring 44 with an associated code-bar 43. A cam 26 on the receiver shaft depresses the associated bellcrank 38, moving the code-bar 43 to the right. If the end 28 is obstructed by the end portion of the armature, the lever 31 is not rotated and the lever 38 returns to its normal position so that the bar 43 moves back to its left hand position. If the end 28 is in register with the aperture 27 the lever 31 rotates when the bellcrank 38 is depressed and its extension 42 latches with the shoulder 41 so that the bar 43 is retained in its right hand position. When the end 35 of the lever 33 is not in engagement with a pin 9 on the wheel 10 the lever 29 is rotated so that the enlarged end 28 is in register with the aperture 27 when the armature 22 is released. The levers 31 are restored to their normal positions by a cam (not shown) on the receiver shaft. Driving-arrangement for cipher wheels. At the end of each signal, a cam 47 on the receiver shaft engages a pivoted bar 48 carrying operating pawls 54, each having a tooth 53, associated with its respective pin-wheel 10 and provided with a laterally extending lug 55 disposed in the path of the pins 9 of the next succeeding wheel 10. If the lug 55 is not in engagement with a pin 9 on the next wheel the tooth 53 moves into engagement with a tooth on the associated wheel 10 which is rotated one step when the lever 48 is raised by the cam 47 and is retained by a pawl 12. The engagement of the lug 55 with a pin 9 on the following wheel holds the tooth 53 out of operative position. The final pin-wheel is invariably moved a step at the end of each signal with the result that the angular positions of the pins of the respective preceding wheels are continuously subject to change.