Patent GB-454553-A (GB)
Title: Improvements in telegraph, signalling, and like selective systems and apparatus
IPC: H04L13/16
Filed: 1935-01-29
Abstract: 454,553. Type-printing telegraphy. SIMS, V., 143, Park Road, Hendon, London. Jan. 29, 1935, Nos. 2886, 7277, 11111, 14317, and 24388. [Class 40 (iii)] In telegraph transmitters or cryptographic apparatus the signal elements are emitted under the control of a mechanical or electrical distributer and their character is determined conjointly or alternatively by two series of control members which may comprise perforated-tape mechanism or permutation bars or the like, or a timing cam, the operation of the control means being sequential and arranged to occur wholly or partly during the operation of the distributer. The relevance of each embodiment to the wording of the main claims is detailed in the Specification. The levers 1A, Fig. 1, which control the signal contacts are jointly controlled by tape-feelers 1J and key-operated permutation bars 1A, levers 1A being liberated in turn by indentations on the start-stop cam 1C, instead of being liberated simultaneously in the usual manner. A control means for alternative use comprises the permutation bars 1D of a keyboard. In another embodiment, Fig. 2 (not shown), the levers are jointly controlled by the distributer cam 1C and by a second cam having its indentations arranged according to a code and geared to the first cam, the code indentations acting in sequence at the same time as those of the distributer cam. In one embodiment, Fig. 3 (not shown), cams co-operating with pairs of levers are employed. In a ciphering transmitter, Fig. 4 (not shown), the polarities applied to the sending distributer by switches controlled by the key-operated bars 1D are reversed or not by further switches operated by ciphering cams. In another transmitter, Fig. 5, signal combinations set up on contacts mounted on drums 5T are applied to contacts 5K which are swept segmentally by wipers 5J, which feed the line through a distributer 5C. In the transmitter shown in Fig. 6, the shaft 6C makes half a revolution for each combination. The keyoperated permutation bars 6D set the pairs of pins 106, mounted on cam levers 102, so that when the levers 102 are rocked by cam 101, the pins act through the rail 107 upon the shaft 116 so as to stress the electrical contact spring 117 if the latter's position does not agree with the signal element that is being set up. Subsequently the corresponding locking stop 122 is allowed by cam 126 to rise so that the spring may assume the required position. In this way the common contact spring 107 is first stressed and then positioned in accordance with the successive signal elements set up on the bars 6D. In another transmitter, Fig. 8, five levers 134 are successively depressed by cams 139 and carry with them five three-armed levers 136 which are set to right or left by abutment plates 133 carried by permutation bars 131. The vertical arms of the three-armed levers act upon rails 141, 142 to turn a frame whereby one or other arm of the U-shaped spring 155 is stressed against the loosely pivoted blade 148, so that when the locking lever 149 is lifted by cam 154 to release the blade the latter conforms to the setting of the permutation bar 131. Start and stop impulses are sent under control of arms 157, 158 operated by the cam grooves corresponding to the first and last code impulses. In a modification, Fig. 9 (not shown), the three-armed lever 136 controls the line contacts through different mechanism. The transmitter shown in Fig. 8 may be adapted for alternative control by perforated tape, Figs. 10, 11, 12 (not shown), upon which feelers act in succession, the feelers being jointed so that their tape-engaging ends move with the tape and return afterwards into alignment under control of springs. Means are provided for enabling the tape or the keyboard to be rendered operative at pleasure. In order that a code cam for sending predetermined signals may be brought into operation in place of the keyboard, a disc 200, Fig. 13, having its periphery waved to form a code cam, may be associated with the transmitter shown in Fig. 8. The disc is turned by a gear 215 driven from the main transmitter shaft 140 and provided with bullet-nosed teeth which engage in corresponding depressions 205 formed in the disc. The edge of the disc engages a bar 234 which is moved longitudinally and is pivoted at 235 to the mechanism for setting the line contact. The gear 215 is carried by a frame 209 pivoted at 211, and is brought into engagement with the disc when required by actuation of the pull rod 225. Means for latching the parts in the requisite positions when they are out of action are provided. In another embodiment, Figs. 15, 16 (not shown), the bars carrying the abutments 133, Fig. 8, which determine the signal elements can be disconnected from the keyboard and brought under the control of a corresponding set of cams on a drum which rotates so as to set up a series of successive signal combinations. Cipher mechanism. Three code rings 292, 293, 294, Figs. 17, 18, jointly control the longitudinal movement of a rod 337 so that for each element of a five-element combination it occupies one or other of two positions. Its movements are combined, Fig. 20 (not shown), with those determined by a transmitter, such as that shown in Fig. 8, for the purpose of enciphering or deciphering a message. The rod 325, for example, has two positions determined by the cam ring 294 through mechanism 331, and carries a roller 322 which is set to right or left in accordance with the cams on that ring. This roller is so mounted, Fig. 19 (not shown), that it can also be moved upwards or downwards by cam projections on the edge 6 of the cam ring 293 ; thus the roller 322 can take up four positions at the corners of a square in the plane of Fig. 17. In two of these positions in sets the next rod 324 to the left and in the other two to the right ; this it does by acting through the short double levers 332, 331 on an arm 334 which is pivoted at 328 to a fixed point and at its other end to the rod 324. Thus the resultant position of the rod 324 is determined by adding the effects of code rings 294, 293. Similar mechanism is shown for adding the movements due to the code ring 292, so as to determine the resultant position of the rod 337. The code rings are moved one step for each signal element by gearing from a shaft 282, Fig. 18, but when necessary they can be disengaged from this shaft and set by hand by means of a gear 342. The code rings are supported by rollers 299 which can be moved to the position 299<1> to enable the code rings to be removed. A different ciphering mechanism, in which the polarity of selected code impulses is reversed by means of switches controlled by a code cam, is described with reference to Fig. 4 (not shown). Specifications 219,696, [Class 40 (iii)], and 455,359 are referred to.