Patent GB-772897-A (GB)
Title: Improvements in or relating to devices for remote indication of the condition of a multiplicity of elements
IPC: B61L7/08
Filed: 1955-01-07
Abstract: 772,897. Electric selective signalling systems. TELEFONAKTIEBOLAGET L. M. ERICSSON. Jan. 7, 1955 [Jan. 7, 1954], No. 624/55. Class 40 (1). An apparatus for the remote indication of the position of a plurality of elements, e.g. signals and switches in a railway system, comprises an individual relay, SI2311 to SI2313, for each element, a first selector SV1, SV2, and SV3, and an impulse emitting device S3, S5, S6, at the sending station for transmitting over a selector MV1, MV2, and MV3, at the receiver, operating in synchronism with the first selector, impulses to an indicating device with a number of memory relays, MI2311 to MI2313, which, depending on said impulses, are arranged to be set in positions according to the condition of a corresponding element, the individual relays being divided into groups, each group being provided with a group relay, SG231 to SG233, the first selector being arranged to test in order the group relays and to test the individual relays within a group if one or more individual relays within such a group indicates a change of condition in an element, the first selector also being arranged to test the group relay next in order of test immediately after a group relay if within the latter group none of the relays indicates a change of condition of an element. Each of the groups is provided with a start relay ST231 &c. arranged to be operated as soon as an individual relay within the corresponding group indicates a change of condition, and returned to its initial position when a corresponding group relay is operated, the group relay being operated in dependence on the condition of its corresponding group only when the preceding group has been tested by the selector. Figs. 1 and 2 show the sending station and Figs. 3 and 4 the receiver. The relays SI2311 to 2313 form a group 231 having a start relay ST231 and group relay SG231 which with other groups 232, 233, form part of an exchange 23 which is in an exchange group 2, and is connected to a line L, further exchanges being indicated at 21, 22, and 31. At the receiver relays MI2311 to MI2313 correspond to the group 231 with a group relay MG231, two further group relays being indicated at MG232 and MG233. MB23 is the exchange relay (exchange 23), two further exchange relays being indicated at MB21 and MB22, and MA2 is the exchange group relay (group 2), MA1, MA3, indicating further exchange group relays. The start relay ST231 is normally energized but if one of the elements changes position and actuates, for example, SI2311, ST231 is released to energize relay S10 and thus energize relay S1. Relay S1 causes S2 and S3 to operate, and S3 causes a first signal impulse in a first impulse group to be fed to the receiver over the upper and lower windings of relay S6, the line L, and relay M1 at the receiver. S3 also energizes relay SV1 over its lower winding. The operation of relay S6 causes relay S4 to operate to break the circuit of S3 which is slow-releasing (50 ms.), and terminate the first impulse. S6 releases, SV2 is energized, and S5 is energized, the release of S6 releasing S4, which also is slow-releasing (50 ms.). The device is now ready to send a second impulse which is polarity reversed owing to the energization of S5 over a wire 2 and conductor a. Release of S4 energizes S3 to energize S6 to start the second impulse, and SV1 is released. S6 energizes S4 to release S3, SV3 is energized, and S5 and S6 release and the second impulse is terminated. S4 releases and S3 energizes to start the third impulse which is not polarityreversed. SV2 is released and S6 operated to energize S4 and S7. Energization of S7 causes SO1 to operate, and energization of S4 releases S3. Previously, SV3 had operated to connect a capacitor and resistor over contact 139 across the winding of S3 to increase the delay (150 ms.), to lengthen the third impulse. Release of S3 releases S6 and SV3 and the first impulse group is terminated. This group consists of three impulses, the second being of reversed polarity and the third relatively longer, and denotes that the calling exchange belongs to exchange group 2. SV3 releases S7 which causes S02 to be energized. In a similar manner a second impulse group of three impulses is sent but S5 does not operate until the second impulse is terminated. When S5 is energized over a wire 3 and conductor b, S7 operates at the beginning of the third impulse, which is polarity-reversed, and SO1 releases. At the end of the third impulse S5 is energized, S03 energizes over the upper winding of SO2 and S10 releases. The second impulse group consisting of three impulses, the last being longer and of reversed polarity, denotes that the calling exchange is exchange 23. Release of S10 causes the group relay SG231 to be energized whereupon ST231 is energized (i.e. returned to normal). Release of S4 causes S3, S6, SV1, and S10 to operate and since S5 is energized, the first impulse of the third impulse group is polarity-reversed. This transmits the information that it is within a group 231 that a change has taken place. When S3 releases the first impulse ceases, S6 releases, and SV2 operates, and since contact 103 of the individual relay SI2312 is made, S5 is energized. When S4 releases, S3 and S6 are energized and transmit the second impulse of the third impulse group, which is polarity-reversed, showing that no change has taken place in the apparatus associated with relay SI2312. S3 releases to terminate the second impulse, S6 releases, and SV3 operates, S5 remaining energized over contact 101 of relay SI2313 and after a delay S4 releases. S3, S6, and S4, then operate, SV2 releases, and S8 operates, and a third polarityreversed long impulse is emitted, denoting no change in the apparatus associated with relay SI2313. When S3 releases again, S6, SV3, and S5 release, the latter owing to contact 105 being broken since SI2311 is assumed to be actuated. S4 releases and S3, S6, SV1, and S9 operate and a first impulse, not polarity-reversed, of a fourth impulse group, is emitted, denoting that a change has taken place in the apparatus associated with SI2312. The operation of S9 releases SG231, releasing S10 and S8. S8 releases S9, and S3, and S6 release and SV2 operates. After a delay S4 releases, S3 and S6 operate, SV1 releases and a second impulse is emitted, denoting that no change has taken place in a group 232 having a group relay SG232. After a further delay a long impulse transmits the information that no change has taken place in the group relay SG233. At the beginning of the long impulse S7 operates to release SO2, and S10 releases, and at the end of the impulse S7 releases again. After the usual delay S4 releases and S12 is energized, thus preventing S3 from emitting signal impulses, and connecting S11 to line L. S11 is energized by a signal sent back from the receiver, energizing S13 to release S12 and disconnect S11 from the line. When S1 releases after a delay S03, S2 and S13 release and all the relays are back to normal. At the receiver, the first impulse in the first impulse group energizes polarized relay M1 over the line L, which since the impulse is not polarity-reversed, energizes M3 and thus M4. The operation of M4 energizes M5, MV1, and M6, and M5 releases M3, which is slow-releasing (50 ms.) and thus M4. Release of M4 releases M5 and energizes MV2. The second signal impulse, being polarity-reversed, causes M2 to be energized to energize MA2 and M4, M4 releasing MV1 and energizing M5 to release M2 and thus M4. Release of M4 causes MV3 to be energized and M5 to release. The third longer impulse causes M1, M3, M4, M5 to operate and MV2 to release and after a delay M3 and M4 release and M7 is energized to energize MO1 and after a delay release M6, M7 and MV3, release of M7 causing M02 to be energized. At the end of the impulse M1 and M5 are released, and MO1, MO2, and the exchange group relay MA2 remain operated. The next three impulses are received in a similar way, but the second non- polarity-reversed impulse causes M3 to be energized instead of M2, and the third longer polarity-reversed impulse causes M2 to be energized. When M2 operates MB23 is energized and when M7 is energized M03 operates to release MA2. M7 releases and releases M02, relays MO1, MO3 and the exchange relay MB23 remaining energized. The first polarityreversed impulse in the third impulse group causes operation of relays M1, M2, M4, M5, MV1, M6 and MG231, the group relay. At the end of the impulse M10 operates and the receiver is now ready to register the condition of apparatus represented by relays MI2311, MI2312, and MI2313. The second polarityreversed impulse connects the lower winding of relay MI2312 between two points of equal potential and the lamp pertaining to that relay remains extinguished. The third long polarityreversed impulse connects the lower winding of relay MI2313 between two points of the same potential, and at the end of the third impulse group, relays MO1, MO3, MB23, MG231, M10, and M8, remain operated. The first non- polarity-reversed impulse in the fourth group causes M3 to operate to energize the lower winding of MI2311 to light a lamp over contact 445 to indicate a change in the associated apparatus. When M4 operates M9 is energized to release M8. When M4 is released MG231 is released, thus releasing M9 and M10. During the second impulse a lower winding of MG232 is connected across points of equal potential, indicating no change in that particular relay group, and similarly, during the third impulse a lower winding of MG233 is connected between points at the same potential. When M7 is energized M04 operates, and subsequent release of M7 releases MO3. M5 is released and M11 is energized and releases MO1 MB23, and MO4 and a D.C. source is connected over contacts 304, 305 to line L to send back a reception signal. After a delay M4 releases to release M11 and the relays are now back to normal. If