Patent GB-345218-A (GB)
Title: Improvements in and relating to coding devices with electrical transmission of signals
IPC: H04L9/38
Filed: 1929-09-10
Abstract: 345,218. Coding-machines. KRYHA, A. VON, 109, Schillerstrasse, Charlottenburg, Berlin. Sept. 10, 1929, No. 27548. Convention date, July 5. Void [Published under Sect. 91 of the Acts]. [Class 146 (ii).] In coding-machines wherein signals are transmitted electrically from a keyboard to a type system through an interposed transposing device which is moved intermittently to alter the key, the keyboard circuits are interlinked electrically with one or more auxiliary circuits which are common to them and after the depression of a key put the transposing device into operation and lock the keyboard circuits during their movement. The depression of a key closes a contact 10, shown diagrammatically in Fig. 1, operating a type magnet 11 of the transmitter and type magnet 12 of the receiver through the interposed transposing device 13, 14. Between the electromagnets 11, 12 and the transposing device are change-over switches with contacts 15, 15<1> and 16, 16<1> in parallel, so that the direction of current can be reversed for coding and decoding. Each receiving-magnet 12, when energized, closes a collecting-contact 19, 20 common to all keyboard circuits, this action taking place after the actuation of the types of both transmitter and receiver, and serving to close an auxiliary circuit II and energize a coding magnet 21 controlling a rotating disc carrying contacts 13 which are movable relatively to fixed contacts 14. The operation of the coding magnet actuates devices which open its circuit contacts 23, 24 and close contacts 25, 26 in the auxiliary circuit III, causing a safety relay 27 in the transmitter to be energized to open contacts 28, 29 common to all keyboard circuits, which are thus deprived of current so that further movement of the types is prevented. The contacts 19, 20 at the receiving end are closed by means of an adjustable type rod 101<1> operated by the magnet 12, and the coding unit 21 energized thereby comprises twelve powerful coils controlling a forked armature 30, Figs. 2 and 3, mounted on a pivot 32 in a block 31. A screw 33 at the free end of the armature 30 abuts against a screw 34 in a lever 35 which is pivoted in the block 31 and, at its free end, has a downward projection 36, Fig. 5, adapted to engage within one of a circle of holes arranged at unequal intervals in a rotating coding-wheel 37. The lever 35 is urged downwardly by a spring-loaded plunger 38 mounted above it in a pivoted arm, and is raised from the coding wheel when the armature 30 is attracted. The coding wheel 37 is mounted upon a sleeve 50, Fig. 3, carrying a coupling-disc 44 provided on its surface with spaced teeth which co-operate with teeth on a continuously rotating coupling-member 47 when the member 44 is lifted upwardly by a yoked lever 42 connected by a link 41 to the armature 30. The lower end of the sleeve 50 carries a toothed wheel 46 geared to a pinion 54, Fig. 4, loosely mounted on an arbor 55 which carries at its upper end the rotating distributing disc 56 provided with a circular series of contacts 13. Current is led to the contacts 13 by a series of slip rings 58 with bearing brushes 60 connected to terminals 61, the contacts 14 being mounted on a fixed distributer disc 66 on pillars 67. Bolts 64 hold the slip rings and the disc 56 together and secure them to a ratchet wheel 65 at the bottom of the block thus formed. Movement is imparted to the ratchet wheel 65 by pawls 68 on a flange 69 connected to the gear wheel 54. The flange 69 is provided with a series of holes equal in number to the number of contacts 13, and a stop pin 71 mounted beneath it is adapted to be lifted to engage one of the holes when the armature 30 of the coding magnet 21 is released, thereby bringing the movable distributer disc to a standstill, with its contacts registering with those of the fixed disc 66. The operation of the contacts 23 .. 26 is controlled by a disc 79, Fig. 5, mounted on a pinion 78 geared to the wheel 46 and provided with a crown of conical projections 80 which co-operate with a lever 81 disposed in their path. The end of the lever carries a tappet 83 which, on rising, engages contact springs 23 .. 26, the lower pair 25, 26 being thereby closed and the upper pair opened. To prevent the tappet 83 from falling back as soon as the lever rides off the crown 80 a pivoted detent 89, Fig. 4, with a nose 91 engaging the tappet 83 is pulled by a spring 90 to hold the lever 81 elevated until the coding-wheel comes to a standstill, whereupon the coding-lever 35, Fig. 5, is lowered and bears upon the end of a lever 87 linked to a tripping-device, which rocks the detent 89 against the action of its spring 90. The safety device of the apparatus comprises a striker plate mounted beneath, and common to, all keys, and connected to a skeleton rocking-frame provided with a lever which co-operates with a slidable pin operated by the armature of the relay 27, Fig. 1, the movement of the armature causing the pin to open contacts 28, 29 in the keyboard circuit, whereupon the end of the skeleton frame lever snaps upwardly into a groove in the pin and holds the contacts open as long as the key is depressed, so that the key circuit is broken and the depression of a second key is ineffective. The spacing of a message into five or ten letter groups is effected by a rotating commutator, which is stepped forward by a pawl and ratchet device at each depression of a key, the periphery of the commutator being provided with transverse contact strips of different lengths co-operating with two contact brushes in alternative key-controlled circuits, the arrangement being such that one closes a spacing-circuit at five letter intervals and the other at ten.