Patent GB-756817-A (GB)
Title: Coaxial electric switches and relays
IPC: H01P1/12
Filed: 1954-10-01
Abstract: 756,817. Electromagnetic relays. WESTERN ELECTRIC CO., Inc. Oct. 1, 1954 [Oct. 7. 1953]. No 28343/54. Class 38(5) A coaxial line switch including one or more mercury relays having the features disclosed in Specification 691.207 comprises, Figs. 10, 11, 13, two mating metal blocks 31, 32 recessed to support therebetween one such relay 35 having a winding 38 surrounding a glass tube 36, the armature 29 serving to connect a lead 40 extending from the tube bottom with one or the other of two pole pieces 46, 47 extending from the tube top. depending on the polarity of the current applied to the winding, the pole pieces being polarized by permanent 223 magnets 92, 93 retained in block grooves 43, 70 by magnetic side plates 62, 63. A conducting sleeve 37 around the tube 36 screens the winding from the coaxial path. The pole pieces 46, 47 are respectively connected to the inner conductors of coaxial terminals 80, 81, by straps 48, 49 passing through block cavities 50, 71 and cylindrical passageways 44, 45; the lead 40 being connected to the inner conductor of coaxial terminal 82 by passing through grooves 72, 91 and, passageway 41. The outer conducting path includes the sleeve 37 and bulges 33, 34 in the blocks 31, 32, the bulges surrounding the mercury pool 39 in the tube 36.and serving to maintain constant the ratio of the diameters of the inner and outer conductors. The terminals 55, 56 for the winding 38 are carried by the block 32 and the switch is mounted by members 83 ... 85 on the coaxial terminals. An arrangement which avoids the slight capacitative coupling between the connected and disconnected paths through the switch comprises, Figs. 14. 24, three relays 106, 107. 108 mounted between mating blocks 101, 102 and having adjacent pole pieces permanently connected by straps 120, 121. accommodated in grooves in the opposed faces of the blocks. The relays are energized simultaneously to connect the coaxial terminal 104 with one of the terminals 103, 105. the relay 106 or 108 of the unconnected line. being connected to a matching impedance 111 or 112 enclosed in stubs 109. 110. The permanent magnets are held in position by magnetic brackets 124 which also support a terminal board 113 for the leads 127, 128, 129 connected to the relav windings. In this arrangement one of the links 120 and 121 is not connected at either end and introduces an undesirable capacitative effect, and to avoid this a switch having four relays is employed. Figs. 1. 5, 22, the relays 151 ... 154 being mounted between two horizontal metal blocks 172, 173 and operating simultaneously tn connect the coaxial terminal 157 with either one of the terminals 159, 160. The unused terminal 159 or 160 is connected to a matching impedence through a coaxial terminal 155, or 156; and the unused one of the leads 190, 194, which respectively interconnect the relays 153, 154 and 151, 152, is earthed through a lead 185 or 186. Metal cover plates 163, 164 overlying the blocks 172, 173 have passageways 182, 188, 193, 196, 198, 199 215 therein receiving the leads e.g. 190. 194, these passageways together with metal cylinders 191. 195, flanged shields 201 surrounding the glass tubes 200, and cup members 202 surrounding the mercury pools; constituting the outer coaxial path. The switch is mounted by plugs 170 and shielded by. magnetic side plates 168. To avoid the "Y" connection 180, five relays 205 ... 209 are used, Fig. 25, to connect the terminal 210 with one of the terminals 211, 212.