GB805684A - Improvements in or relating to switching arrangements for coaxial cables - Google Patents

Abstract

805,684. Mechanical switches without quickaction. MARCONI'S WIRELESS TELEGRAPH CO. Ltd. Feb. 18, 1957 [May 1, 1956], No. 13374/56. Class 38 (5). A switch, Fig. 1, for connecting the inner conductor of any one of a set A, B, C of coaxial cable structures with the inner conductor of any one of a second set 1, 2, 3 of similar structures comprises a series of pivoted tongues for each structure, e.g. tongues 4a, 4b, 4c for structure A, tongues 4d, 4e, 4f for structure B &c., each tongue being swingable either to a position in which it contacts the unpivoted end of a tongue in a series appropriate to the other set of structures. Thus, as shown, transmitter A is connected to aerial 2 via tongues 4a, 4b, 6b, transmitter B is connected to aerial 3 via tongues 4e, 4d, 4f, 6f, 6c and transmitter C is connected to aerial 1 via tongues 4g, 6g, 6d, 6a. Fig. 3 shows a mechanism for selecting and bringing into contact a pair of tongues, one in a transmitter series and one in an aerial series. With the aerials and transmitters as shown in Fig. 1, there would therefore be nine such mechanisms. Each mechanism comprises a wheel 18 mounted on the same shaft as and rotated by a star wheel 17, the wheel 18 carrying wires 51, 52. Wire 51 operates the tongue 6a via a lever 23 pivoted at 26 and bearing against a recessed cam 24 and the wire 52 operates the tongue 4a via a similar lever and cam 21, 22. The star wheel is rotated by one set of teeth 19 on a rod 15 common to the three mechanisms corresponding to each transmitter. The sets of teeth appropriate to the three mechanisms are spaced axially and circumferentially on the rod so that, to operate a particular mechanism, the rod is first burned to engage the appropriate set of teeth in the star wheel and then moved axially to rotate the star wheel. The initial axial movement of the rod 15 changes over a switch 29, Fig. 4 (showing the arrangement for all three operating rods), from a position a in which a condenser 30 is charged to a position b in which the condenser is discharged to operate a solenoid 31 which has hitherto prevented further axial movement of the rod. Operation of this solenoid also changes over switch 32 from position a to position b. Rotation of the rod 15 to select the appropriate mechanism also operates a rotating switch WA, WB or WC, each having contacts W1, W2, W3 corresponding to the selector positions and interconnected as shown, so that if the rod of another transmitter is turned to the same selector position, the solenoid of that rod is short-circuited and axial movement of the rod is prevented. Thus it is impossible to connect more than one transmitter to the same aerial. Fig. 5 shows an alternative selecting and operating mechanism for the tongues, there being one such mechanism for each tongue. Each tongue is moved to the actuated position shown dotted) by rocking a sector 37 clockwise, the sector driving a slotted crank 38 on the tongue shaft through a spring-loaded pin 47. A common selecting bar 42 is provided for the mechanisms corresponding to each transmitter and aerial, the bars each having three slots 41. Movement of the sector to the actuated position is prevented by an obstruction 40 unless the bar 42 is moved so that the appropriate slot is in the position behind the obstruction. In the actuated position the sector 37 allows a switch 43, held open by contact of a spring- arm 44 with the sector, to close. Fig. 6 shows the interconnection of three switches 43T belonging to the different mechanisms of the same transmitter and three switches 43A belonging to mechanisms each appropriate to a different aerial. Thus, unless one series pair of switches is closed there is no H.T. supply to that transmitter. The contacting ends of the tongues may be shaped as shown, or may each incorporate a pair of spring balls so that when in contact the balls on one tongue alternate with the balls on the other tongue around a, ring of four contacts.