Patent GB-190309344-A (GB)
Title: Improvements in Apparatus for Operating and Controlling Railway Points, Signals, Point Locks, Crossing Gates, and the like.
Inventor: EVANS GUY
Filed: 1903-04-24
Granted: 1904-04-23
Abstract: 9344. Evans, G. April 24. Semaphore &c. signals; controlling and locking signals; interlocking; indicators, point or switch and signal.-Relates to pneumatic apparatus for operating and controlling railway points, signals, point locks, crossing-gates, and the like, and more especially to improvements in apparatus of the kind described in Specifications No. 183, A.D. 1900, and No. 5575, A.D. 1901. Only two air pipes are used, acting alternately as indicating and operating pipes as described in Specification No. 5575, A.D. 1901, and only one indication cylinder and piston is employed in connection with the point-operating lever or bar in the interlocking-apparatus ; two of the relay valves are dispensed with, and the return-indication air impulse to the single indication cylinder is controlled through the operating and controlling valve in connection with the operating-lever. Fig. 1 shows the application of the apparatus for operating and indicating the movement of switch points. An operating bar or lever 1 has an interlocking-slot 3 connected to the usual tappet 4, an indicating slot 3 connected to the single indication cylinder 5, and pivoted tappets 91, 91<a> for operating the main controlling-valve 9 through the pivoted lever 88 and projecting arm 89. This main valve is formed of two double piston valves 10, 11, and two poppet valves 12, 13 which control the various ports and passages, and it is connected through the pipe 33 to the compressed-air supply 32, and through pipes 28, 29 to the diaphragm relay valves 34, 35. These relay valves have piston valves 42, lift valves 44, and central tubes fitted to the diaphragms and provided with valves 40 ; they control the admission of compressed air to the point-locking cylinder 52 and the point-operating cylinder 36, through a valve device 50, and also transmit return impulses to the single indication cylinder 5. When the interlocking-bar 1 is pulled in the direction of the arrow, the piston valve 10 is raised, the piston valve 11 is depressed, and the valve 13 is opened, the exhaust passages 17, 18, 19, 20 being thus closed and compressed air allowed to pass along the pipe 28 to the relay valve 34. The diaphragm 37 is raised by the compressed air, and the piston and lift valves 42, 44 are operated to allow air to pass through the pipe 49 to the valve device 50, where it moves the piston valve 55 and passes through the pipe 69 into the point-locking cylinder. When the piston 71 has moved sufficiently far to release the locking-bar 78 from the catch 75, air passes through the pipe 81 into the pointoperating cylinder 36, and the points are operated. After the points have been moved over, the movement of the piston 71 is completed, which causes a second catch 74 to engage and lock the bar 78. This movement also uncovers a pipe 80 and allows an indicating-impulse to pass and move over the valves 65<a>, 66 and thence through the pipe 51, valve 40 of relay valve 35, and pipe 29 to the main valve. The compressed air passes through the channels 21, 22, 23 to the single indication cylinder 5, moving upwards the piston 6 and completing the movement of the bar 1, which releases the tappet 91a and allows the valves 10, 11, 12 to return to their normal position, thus leaving the bar ready for the reverse movement. When the points are reversed, compressed air first passes through the pipe 29 to the relay valve 35, and the indicating-current returns through the pipe 49, relay valve 34, and pipe 28. The apparatus is also shown applied for operating and indicating the operations of a semaphore signal. In this case, the tappets and slots of the interlocking-bar, and the construction of one of the relay valves, are varied, as it is only necessary to indicate the danger position of the signal.