Patent GB-190408421-A (GB)
Title: Improvements relating to Crossing Permit and like Apparatus for Controlling Trains on Railways.
Inventor: HIGLEY FREDERICK HENRY
Filed: 1904-04-12
Granted: 1905-05-12
Abstract: 8421. Higley, F. H. April 12. Controlling traffic on railways, staff and ticket systems for. - Relates to crossing permit apparatus for use in combination with Tyer's No. 5 tablet apparatus, and consists in certain improvements in Tyer's crossing permit apparatus for the purpose of enabling the same line-wire to be used for the working of such apparatus and for the No. 5 tablet apparatus. The permit apparatus is brought into use when two trains are started from opposite ends of the same section with instructions to cross at an intermediate siding. The method of working is as follows : - The operator at one station A, termed the ' controlling station,' having obtained B's permission, extracts an ordinary 'through' tablet from his No. 5 instrument, and locks it in the tablet recess in the crossing permit apparatus. The removal of the tablet reverses the connection of A's battery to line and earth, and thereby prevents the subsequent withdrawal of a 'through' tablet from B's apparatus. The iniertion of the tablet in the recess of the crossing permit apparatus enables A to withdraw his slide and extract the crossing permit. In doing so, A adds to the normal line battery an increment battery of sufficient strength to enable the line current to energize a non-polarized relay of B's crossing permit apparatus, which is placed in series with a resistance of such amount as to prevent its actuation by the normal battery. The operator at A is now able to release B's crossing permit by depressing the bell plunger of his No. 5 instrument. The crossing permits are exchanged at the crossing-point so as to be returned to the instruments from which they were withdrawn. Until they have both been returned, A is unable to release the 'through' tablet in his permit apparatus and return it to the No. 5 instrument. Fig. 1 shows the apparatus at the controlling-station A, the ordinary No. 5 apparatus being shown at the lefthand side of the Figure. The apparatus at the other station B is shown in Fig. 2, the ordinary battery Z A and an increment battery A C in series with it being provided at each station. The operator at A having extracted a 'through' tablet from his No. 5 apparatus, the switch t will have reversed the connection of the battery to earth and line L so as to prevent the actuation of the polarized relay 30 at B's station in such a manner as to allow of the euergization of the tablet out' unlocking electromagnet 25. At the same time, the switch e will have reversed the connections of the 'tablet out' electromagnet 25 and tablet in' electromagnet 25<a> at A'sstation, relatively to the polarized relay 30, so as to prevent the energization of the ' tablet out' electromagnet 25 by B's non-reversed current. In other words, the No. 5 instruments at A and B are out of unison. When the operator at A inserts the 'through' tablet in the recess of his crossing permit apparatus, he closes thereby the contacts 44, 45 and 62, 61. The covering flap is locked by the armature of an electromagnet l, so that the through' tablet cannot be withdrawn until this electromagnet is energized. The operator at A now depresses the plunger T and closes a local circuit through the electromagnet k, which unlocks the slide carrying the crossing tablet and enables it to be extracted. The circuit is as follows :-C, 41, 42,43, 44, 45, 46, 47, k, Z. The crossing tablet having been withdrawn, the circuitbreaker P breaks the connection between 42, 43 at P, M, Figs. 1 and 3, and at the same time swings over the switch arm C' from B to E' so as to add to the normal battery Z A the increment battery A C. The operator at A next depresses the bell plunger j of his No. 5 instrument, the strong current operating the non-polarized relay of B's crossing permit apparatus through an added resistance. The circuit is as follows :-C (A's instrument), E', C', 1, 2, 3, 4, 5, 6, 7, 8, 9, line (B's instrument), 9, 8, 7, 15, 16, 17, 50, 51, 52, 53, earth (A's instrument), 10, 11, 12<a>, 12, 13. 14, Z. A local circuit being now closed through B's releasing electromagnet k, he is able to remove his crossing tablet, thereby opening the circuit-breaker P. The local circuit is as follows :-C, 54, 55, 56, 57, 58, k, 59, Z. When the crossing tablets have both been returned to their own instruments, the operator at B is able to release the through' tablet locked up in A's crossing permit apparatus. For this purpose, the operator at B depresses simultaneously the bell plunger j of his No. 5 instrument and the switch plunger S of his crossing permit apparatus. The circuit is as follows, the strong battery being used :-C (B's instrument), E', C', 1, 2. 3, 4, 5, 6, 7, 8, 9, line (A's instrument), 9, 8, 7, 15, 16, 17, 60, 61, 62, 63, 64, earth (B's instrument), 10, 11, 12<a>, 12, 13, 14, Z. The relay at A being thus energized, the local circuit of the ' through' tablet releasing electromagnet l is closed, and the tablet withdrawn and returned to the No. 5 apparatus. The local circuit is as follows :-C (of local battery), 41, 42, 43, 65, 66, 67, 68, l, 69, Z. At any stage in the operations, the operators can signal to each other on the single stroke bells 30<a> controlled by the polarized relays 30.