Patent GB-100306-A (GB)
Title: Improvements in Electric Signalling Systems and Apparatus particularly applicable to Automatic Multiplex Printing Telegraphy.
Inventor: DIXON AMOS FREDERICK
IPC: H04L5/16
Filed: 1916-04-01
Abstract: 100,306. Dixon, A. F. April 22, 1915, [Convention date]. Type - printing telegraphs.-The automatic transmitter of a print. i n g telegraph system is rendered inoperative, and a signal comprising predetermined combinations of impulses transmitted, by the single manual cperation of an apparatus comprising a spring motor and a cam shaft, the cams of which operate switches to alter the normal circuits of the transmitter and to establish circuits for the signal impulses. Construction. The signal transmitter comprises a shaft 8, Figs. 2, 3, and 4, upon which are mounted cams 9, 10, 11, an escapement-wheel 13, and a pinion 12 engaging a gear-wheel 28 loosely mounted on a shaft 29. Secured to the shaft 29 is a ratchet-wheel 27 engaged by a pawl 26 mounted on the wheel 28. One end of a spring 25 is secured to the shaft 29, the other end being secured to the casing; while the spring is tensioned by the insertion of a finger in one of the holes in a segment 35, the movement of the segment being limited by a finger-stop 37. The rotation of the shaft 8 is controlled by an escapement 42 operated by a magnet 40. The cams 9, 10, 11 are operated with five raised surfaces, corresponding in number to the maximum number of series of impulses to be transmitted, and are arranged to actuate switches 15, 19, 20, each of which consists of two fixed contacts and a movable contact operated by the raised surfaces of the cams. Secured to the shaft 29 is an arm 45 adapted to control a switch 46 comprising two fixed contacts 49, 50 and a movable contact 47. Operation. When it is desired to interrupt the normal working of the transmitter T, Fig. 5, and to send a " start " signal, a finger is inserted in the first hole marked " Start " in the sector 35, and the shaft 29 rotated to tension the spring 25, until the finger engages the finger-stop. The movement of the sector 37 also operates the switch 46, breaking the normal circuit at the contacts 47, 48 and completing the circuit of the escapement magnet 40 at the contacts 47, 50. When the brush arm 88 of the distributor D reaches the contact segments 86, 87, the magnet 40 is energized from the battery 95 over the contacts 47, 50; and the left-hand winding 98 of a relay 97 is energized over the contacts 96, 101 and a magnet 66. The operation of the relay 97 breaks its operating-circuit at the contacts 96, 101, and closes a locking-circuit for itself and the magnet 66 from a battery 102 over contacts 100, 101. The energization of the magnet 66 causes all the movable contacts 61 - - 65 of the transmitter T to engage their right-hand fixed contacts, which are connected to the positive side of a divided battery 76 by the operation of the switch 20 by the first movement of the cam 11. The movable contacts 61, 62, 64 of the transmitter T are connected directly to the contact segments 71, 72, 74 of the distributor D; while the contacts 63, 65 are connected to the contact segments 73, 75 through the switches 15, 19 respectively. After the operation of the segment 35 and the passage of the brush arm 88 over contact segments 86, 87, the shaft 8 is moved, under the control of the magnet 40 and escapement 13, 42, to cause the contacts 16, 16<1> to engage 18, 18<1> and contacts 61 - - 65 to engage their right-hand contacts due to the energization of the magnet 66. Upon the succeeding passage of the brush arm 88 over contact segments 71 - - 75, two positive impulses, one negative impulse through the switch 15, and two positive impulses are transmitted to the line L from the battery 76. The next passage of the arm 88 over contacts 86, 87 again energizes magnet 40 to step the cam shaft 8 around ; but no alteration of the impulse circuits takes place until the next step of the cam shaft, when the switch 19 is operated to disconnect contact segment 75 from the positive pole of the battery 76 and connect it to the negative pole through switch 19, so that upon the next passage of the arm 88 over the contact segments 71 - - 75, two positive impulses, one negative impulse, one positive impulse, and a negative impulse are transmitted to line L. The next energization of the magnet 40 causes the switches 15, 19 to assume their normal positions, so that upon the next passage of the arm 88 over the contact segments 71 - - 75, five positive impulses are sent to line L. The next energization of the magnet 40 causes the switch 20 to assums its normal position in which all the contact seg ments 71 - - 75 are connected to the negative pole of the battery 76, so that upon the next passage of the arm 88 over contact segments 71 - - 75, five negative impulses are sent to line. The next energization of the magnet 40 causes the arm 45 to engage contact 45, thereby breaking the magnet circuit and closing the circuit of the second winding 99 of the relay 97, whereby the armature 100 is released and the circuits restored to their normal condition. In the arrangement shown, the above set of signal impulses may be sent from one to five times, according to the signal it is desired to send. In a duplex system the receiving operator at one end of the line may signal the distant transmitting operator by operating the signal device connected with his local transmitter. Specification 26,916/08 is referred to.