Patent GB-190410558-A (GB)
Title: Improvements in and connected with Railway Signalling
Inventor: SYKES WILLIAM ROBERT
Filed: 1904-05-07
Granted: 1905-06-07
Abstract: 10,558. Sykes, W. R. May 7. Indicating and recording movements of trains; contacts, electric ;controlling and locking signals ; interlocking; electric generators operated by passing trains.-Electric switch counting - apparatus is operated by vehicles passing over electric track treadles in entering a protected section, so as to place and lock the signals protecting the section at " danger " until every vehicle has passed out of the section over similar treadles, either by the same or different paths. An ordinary Sykes' signal reverser is included in a circuit with an electromagnet 9, Figs. 1, 2, and 3, the armature 10 of which forms a lock on the signal lever L. Assuming the protected section to be empty, the catch-bar 1 of the signal lever L is raised. The drop box 2, being thereby raised, allows spring contacts 3, 4 to close, thus completing the circuit through the switch counting-apparatus, the reverser, and the electromagnet 9, and so withdrawing the lock 10 and permitting the lever L to be pulled over to set the "line-clear" signal. The switch counting-apparatus comprises a spring contact 43 carried on a metal disc 44 insulatedly fixed on a shaft 50, which is rotated by an escapement wheel 52 and an escapement armature 53 of an electromagnet 56. This disc 44 is fixed opposite a similar disc 40 similarly actuated from an electromagnet 35. Similar discs 19, 23 with spring contacts 21, 22 are fixed below the discs 44, 40, with which they are geared through wheels 49, 51 and 27, 30. The circuit through the magnet 9 and the signal reverser passes through the four discs by means of fixed brushes 46, 39, 25, 18, and the two pairs of contacts 43, 42 and 21, 22. The magnet 56 is energized each time a pair of vehicle wheels passes over an electric treadle into the protected section, causing the contacts 43, 21 to move just as many steps away from the contacts 42, 22 as there are pairs of wheels. The lower pair of discs is employed in case there are very many vehicles moving into a section, so as to make the upper disc 44 rotate more than once. Thus the circuit through the reverser and locking-electromagnet 9 is broken when the first pair of wheels enters a protected section, so placing the signal at "danger," and the circuit is only made again to allow " line-clear " to be given when the contacts 42, 22 make an equal number of steps in the same direction due to the whole of the vehicles passing out of the section over treadles, which repeatedly energize the electromagnet 35. A miniature semaphore indicator, Fig. 2, shows when all the vehicles have passed out of the section. Fig. 4 shows a modified form of switch counting-apparatus in which the discs 40, 23 above are replaced by fixed insulating-rings 40<a>, 23<a> provided with contact-plates 42<a>, 22<a>. The discs 44<a>, 19<a> are rotated step by step in one direction, as each pair of wheels enters the protected section, by a hook armature 55<a> of an electromagnet 56<a>, and are oppositely rotated step by step, as each pair of wheels leaves the protected section, by a hook armature 34<a> of an electromagnet 35<a>. These hook armatures engage with studs projecting from the face of a star-wheel 64 keyed on the shaft 50<a>, and provided with a spring detent 62. The lower disc 19" serves the purpose of the lower pair of discs in the apparatus shown in Fig. 1. Fig. 5 shows one form of track treadle, on which selector plungers 70, 73 are carried on a beam 71 pivoted to the track rail, and close contacts 66, 67, 77, 75, while the central sender plunger 79 is depressed against a spring 80 to close contacts 85, 83, and so to send a current from a battery X", Fig. 9, or a battery X<b> to the "locking" magnet 56 of the counting-apparatus, or the unlocking or releasing magnet 35 of the counting-apparatus, according to whether the selector plunger A or the selector plunger B has been depressed before the sender plunger B. Vehicles entering the protected section YZ from No. 1 Bay therefore actuate the plungers A, B, and the counting-apparatus step by step, and on leaving the section YZ in the same direction actuate the plungers C, B, to return the counting-apparatus to its original position. If the plunger A has been first actuated, the succeeding actuation of the plunger C will have no effect, .because the vehicle wheel actuating the plunger C will then have left the sender plunger B, and similarly the primary actuation of the plunger C will cause the succeeding actuation of the plunger A to be ineffective. Similar treadles may be placed at the other two exits from the section YZ at D, E, F and J, H, G, No. 2 Bay, but two modified forms of treadles are described for use at these places, one counting-apparatus only being used for a single protected section. Fig. 7 shows a magneto treadle to be used at D, E, F, and provided with external selector plungers 112, 115 on a pivoted bar 113 as before, but with a central treadle 126 provided with a spring 125, and carrying a stirrup 123 with a permanent horse-shoe magnet 122, which moves within a fixed coil 121, thus generating a current, which operates a relay 90, Fig. 9, provided that the selector treadle D has been previously depressed by a pair of wheels leaving the section YZ. The attracted armature 88 of the relay 90 then closes the circuit of the releasing-magnet 35 of the counting-apparatus. Fig. 8 shows another form of treadle to be used at G, H, J, and provided with a curved sway-bar 95 carrying the central sender plunger 100, and attached to the selector contacts 98, 104 through links 96, 102 and bell-crank levers 97, 103 on fixed pivots. According to whether the end J or the end G is first depressed, the contacts 104 or the contacts 98 are horizontally moved into position beneath the sender plunger 100. A pair of wheels leaving the section YZ, Fig. 9, by No. 2 Bay will depress the end J and the plunger H, and so close a circuit through a battery W and the relay 90, again releasing the counting-apparatus one step as before. The selector contacts F, G of their respective treadles serve the same purpose as the selector contact A, but are inoperative in the present example. A known form of signal reverser for a pneumatically-operated signal may be employed instead of the Sykes' reverser, and the actual interlocking or controlling of the signals may be effected under the control of the above apparatus either by mechanical, electric, pneumatic, or hydraulic power or any combination of these.