Patent GB-190414159-A (GB)
Title: Improvements in Railway Signalling Systems and Apparatus therefor.
Filed: 1904-06-22
Granted: 1905-06-22
Abstract: 14,159. Cossman, M., Despons, E., and British Pneumatic Railway Signal Co. June 22. Semaphore &c. signals ; contacts, mechanical ; signal levers; controlling and locking signals; interlocking. - In improvements i n the apparatus described in Specifications No. 183, A.D. 1900, and No. 9936, A.D. 1903, signals and points are operated pneumatically by fewer levers than formerly. At a cross-over road the points and signal are set by one lever for each direction. Mechanical treadles actuated by the wheels of passing trains are used for locking signals while a train is on a section, and means are provided for unlocking the signal should the train be shunted out of the section on to another line. A sliding valve with special ports is used in operating signals and points. At a cross-over road, as shown in Fig. 2, the signal and points for either direction may be set by the movement of one lever 1, 2. The slide valves, three-way valves, relay valves, cylinder movements, and motion plates are of known construction. The lever 1 is pulled as far as possible, its motion being limited by the shoulder of the camslot, and the slide valve 5 then allows air from the main 100 to pass into the cylinder 7, to move the valve 37, and also to allow air to pass through the cylinder into the pipe 10, thence through the valve 37 (when its travel is complete), and through the three-way valve 45 to the relay valve 12. This valve admits air from the main to the cylinder 13, the piston of which is driven forward and moves the motion plate 13<a> and through it the points B and the slide valve 14. When the valve 14 has completed its travel, air passes along the pipe 17 to the relay valve 18, by which the points A are moved over; when their motion is complete, the slide valve 20 admits air to the pipe 22, which passes to a cylinder 23 to operate the slide valve 25. When the movement of this valve 25 is complete, air passes through the cylinder 23 and the valve 25 to the relay valves 28, 29, which are opened to admit air from the main 100 to the cylinders 30,31, and thus to cause the lever 1 to complete its stroke, showing that the points are set over, and to lock the lever 2 in its normal position. The valve 25, when pushed over as above described, also allows air from the main 100 to pass through to the pipe 34, slide valve 35, pipe 36, and the valve 37, which is pushed over by the piston of the cylinder 7, and thence to the pipe 38 and the relay valve 39, which causes the signal C to be set by the cylinder 40 and rods 40<a>, thus completing the setting of the signal and points by the movement of the lever 1. To replace the signal C and restore the points A, B to normal, the lever 1 is moved back as far as possible, thus admitting air through the slide valve 5 to the pipe 53 and cylinder 7 ; the valve 37 is thus returned to normal, and admits air through the pipe 54 to the relay valve 55, which in turn admits air to the cylinder 40 to set back the signal C and open the valve 56". The air thus admitted through the three-way valve 77 to the relay valve 63 causes the points B to be returned to normal. Air also passes to the relay valve 66, which causes the points A to be returned to normal and air to pass through the pipe 68 to the cylinder 23 to return the valve 25, which then shuts off the air from the main 100. Air from the pipe 68 also passes through the cylinder 23 to the pipe 69, and then through the valve 25 to the pipes 71, 73, which respectively lead through the slide valves 37, 35 to the relay valves 28<a>, 29<a> ; these valves admit air to cylinders which complete the movement of the lever 1 and to hold the lever 2 in position. The valves 35, 37 and their operating-cylinders may be replaced by a valve as shown in Figs. 6 and 7. Such a valve may be connected to the valves 5, 2<a> by links, or may form part of those valves. Figs. 6 and 7 show the last-mentioned form of the valve, Fig. 6 being a plan of the valve seat and Fig. 7 a plan of the valve slide, which is movable in the direction of the arrow. The pipes are indicated by the same reference numerals as in Fig. 2. The ports a<1>, l<1>, l communicate through the port b with the exhaust port c. When the lever 1 is pulled to operate the points, the ports m<1> connect the main 100 through ports m, l to the pipe 6. On the completion of the stroke of the lever 1 by the return air, the pipes 36, 38 are connected through the ports a, d, d<1>, a<1>. Similar connections are made for the return of the points and signal to normal. For the purpose of protecting a section on which a train is standing, the apparatus shown in Fig. 3 is used. Assuming a train to be moving from left to right, the lever X is reversed, thus admitting air from the main 100 through the valve 4 to the pipe 5 and operating the motion plate 8. The plate 8 moves the locking-bar 3 by means of the rods 11, 12, and, by means of the rod 8<a> and the crank 9, sets the treadle 2 so that a train passing over it will depress it. While the treadle 2 is raised, the lever 13 is held against movement under the action of the counterweight 33. The lever 13 is connected to the valve 14, and, when the piston movement in the cylinder 7 is completed, this valve is opened and allows air to pass through pipes 15, 16 to the relay valve 17, which operates a similar arrangement of apparatus to that described above, but without the locking-bar and including a signal 22 controlled by the rods and the counterweight 29. When the treadle 1 is raised, the valve 24 passes air to the pipe 27, but the valve 25 is closed. A train entering the section at the end A depresses the treadle 1, releases the lever 20 from the lever 23, and the counterweight puts the signal to 'danger' and opens the valve 25,40<a>. The valve 25 then admits air to the pipe 27, a diaphragm valve 28<a>, and the relay valve 31, which admits air to a locking-cylinder 34 of the kind described in Specification No. 9936, A.D. 1903, to lock the lover X in its position and, through the interlocking frame, to prevent the setting of conflicting points or signals. As the train passes over the treadle 2, this treadle is depressed, and allows the counterweight to return the lever 13 and the valve 14 to their normal positions, thus exhausting air from the pipe 16 and allowing the valve 17 to drop and exhaust the pipes 26, 28 and the relay valve 30, which then exhausts the cylinder 34. This unlocks the lever X, which may then be replaced by the signalman as far as the cam-slot will allow. This exhausts the air in the pipe 5 through the valve 4 and also the pipe 15. Compressed air is also admitted to the pipe 38 and relay valve 39, which causes the piston of the cylinder 18 to return to normal, moving with it the valves 24, 25 and treadle 1. When the signal is fully at danger, air passes through the pipe 40, valve 40<a>, and three-way valve O<5> to the relay valve 42, to return the piston of the cylinder 7 to normal position if no part of the train is on the bar 3. When this movement is completed, air passes through the valve 44 to a valve 46, which admits air from the main 100 through the three-way valve 48 to the relay valve 50. This valve admits air to the cylinder 51, thereby completing the travel of the lever X. Should a train enter the section A B and be shunted out of it, the lever X may be unlocked and the treadles 1, 2 restored to normal in the following manner :-Assuming that a train standing on the bar 3 requires to be shunted over the lines K, K<1>, the lever X<1> is reserved, thus admitting air to the diaphragm valve 28<a>, which opens the relay valve 31 to exhaust. The valve 31 opens the cylinder 34 to exhaust and unlocks the lever X, which can then be put back to the normal position so as to release the levers for the points K, K<1>. The air in the pipe o<1> also passes through the valve 48 to the relay valve 50, which causes the lever X to complete its travel. When shunting is completed, the lever X<1> is put back as far as possible, admitting air from the main to the pipe o<4> and through the valve o<5> to the relay valve 42. The action is then completed in the known manner.