Patent GB-100636-A (GB)
Title: Improvements in Air Brake Apparatus.
IPC: B60T15/48
Filed: 1916-05-05
Abstract: 100,636. California Valve & Air Brake Co., (Assignees of Neal, S. G.). June 10, 1915. [Convention date]. Fluid-pressure.-Comprises (1) a triple valve of the kind with which service applications are effected by train-pipe air; the valve admits the auxiliary reservoir air to the brake cylinder only by a sudden and pronounced reduction in trainpipe pressure, a temporary emergency application by train-pipe air is obtained by a sudden but brief reduction in train-pipe pressure, the brake cylinder pressure braking down in this case to service pressure; (2) an augmenting-reservoir D associated with each car equipment and connected to the train-pipe in service applications, but after equalization or when the brake-cylinder pressure is greater than train-pipe pressure, becoming in effect part of the brake-cylinder capacity; (3) a special quick-action release valve E, a graduated release, however, being also obtainable; (4) an auxiliary brake cylinder C<1>, Fig. 3, which may be connected at all times to the main cylinder C, or may be connected with the triple valve so as to be charged only in emergency applications, a temporary emergency application being obtainable in the latter case in which both cylinders are first charged and the pressure subsequently allowed to leak off completely from the auxiliary cylinder and partly from the main cylinder. (1) The triple valve, Figs. 1 and 4, comprises chambers 2, 4 separated by a movable abutment 3 and connected respectively to the train-pipe at 1 and the auxiliary reservoir B at 5. A second abutment 29 separates chamber 25, open at 25<a>, 86 to the brake cylinder C, from chamber 21 connected by passage 22 with chamber 41, which is also connected by passage 85<a> through check valve 85<b>, Fig. 2, with the cylinder C. A third abutment 39 separates chamber 41 from chamber 40, which is permanently open to chamber 39a, and both of these chambers are constantly open to train-pipe chamber 2. Chamber 39<a> is separated from chamber 81 by abutment 63. There are leak ports 79, 79<a> be. tween chambers 81, 39<a>. The abutment 63 carries a dome 64 sliding upon a fixed part 57. An adjustable stop 64<x> limits the downward movement of this abutment. The port 79<a> is arranged in the stop 64<x> and thus becomes closed when the abutment is depressed. The port 79<a> communicates with chamber 39<a> by a groove in the dome 64. Communication is adapted to be established between the chambers 39a, 40 and the chamber 41 when the abutment 63 is depressed, by means of a vadve 69 seating upwardly in the fixed part 71 and operated by a cross-bar 68 fixed to the dome 64, so as to open passages from the chamber 39a to passages 84 connecting with chamber 41. A check valve 73 formed as a cap prevents backflow. The chamber 41 is normally open to atmosphere by passage 61, but is closed by upward movement of the abutment 39, which carries the valve 51 by a yoke. The valve 51 is integral with the valve 53 controlling communication between chambers 4, 41. Fixed to the abutment 29 is a tubular rod 6 with an extension 17 adapted to slide loosely in the head 8 of the abutment 3, and having a shoulder 11 co-operating with the abutment so as to control communication between chambers 2, 4. The chamber 2 can connect with the chamber 25 through the orifices 15 and the tube 6 and past the check valve 32<a>, valve 32, and orifices 28<a>. A rod 34 sliding in the extension 28 carries the valve 32 and also the valve 35 controlling exhaust from the chamber 25. In charging, the abutment 3 is lifted to admit train-pipe air from chamber 2 past valve 11 to chamber 4 and the auxiliary reservoir B. Abutment 29 is also lifted and with it the valve-rod 34, opening the brakecylinder exhaust valve 35. Chambers 39<a>, 40 will also be at train-pipe pressure, and chamber 81 will be charged through the ports 79, 79<a>. With a service reduction of train-pipe pressure, the abutment 3 is depressed and moves down also the abutment 29, closing the exhaust valve 35 and opening the valve 32 to admit train-pipe air to the brake cylinder B. When the brake cylinder pressure acting beneath the abutment 29, together with the train-pipe pressure on abutment 3, is equal to the auxiliary-reservoir pressure on abutment 3, the abutments are again raised. With the abutment 29 half the area of abutment 3, as shown, the pressure built up in the brake cylinder will be twice the fall of train-pipe pressure. If, after an application, the train-pipe pressure is increased to a value below the normal, the exhaust valve 35 will be opened, but only until a. corresponding reduction has taken place in the blake cylinder and chamber 25. A temporary emergency application is effected by a brief, but suden, train-pipe pressure reduction and causes the abutment 63 to be depressed, because leakage from chamber 81 by ports 79, 79<a> will not be fast enough to equalize the pressure therein with that in the chambers 39<a>, 40. Valve 69 is thus opened, and train-pipe air flows from chamber 39<a> to chamber 41, thence to the brake cylinder by passage 85<a>, until equalization between chambers 81, 39<a> is effected by port 79, port 79<a> being closed at this time. The brake cylinder pressure will in this case leak down through exhaust valve 35 to that corresponding to an equal service train-pipe pressure reduction. With a sudden and pronounced emergency train-pipe pressure reduction, the pressure in chamber 41 builds up sufficiently to lift the abutment 39 before equalization between chambers 81, 39a occurs, and opens the valve 53 to admit auxiliary-reservoir air from chamber 4 to the chamber 41 and the brake cylinder. For convenience in mounting, the triple valve may be arranged in two separate parts provided with pipe connexions and comprising respectively the service and release chambers 2, 4, 21, 25 and the emergency chambers 41, 40, 81. A hand-operated retainer valve 130 may be applied to the exhaust passage 131. (2) The augmenting-reservoir D, Fig. 1, is normally connected, with the train-pipe through connexions E, F, 117, 117<a>. The valve E comprises a diaphragm 107 open below to the train-pipe and above to the brake cylinder by chamber 25 and pipe 104. The diapnragm 107 carries a tubular valve 113 adapted to seat on a fixed open-ended post 111, and has also a central passage with a valve 107<a>. When train-pipe pressure exceeds brake-cylinder pressure, the abutment 107 is raised, and the valve 107<a> held closed by the stop 119, so that the reservoir in service applications augments the train-pipe capacity. After equalization, however, the abutment is depressed, and the reservoir is closed to the trainpipe; but air can flow therefrom to the brake cylinder to compensate for leakage. (3) The quick-release valve F operates to connect the auxiliary reservoir to the train-pipe when the train-pipe pressure is raised, and comprises chambers 97, 98 open to the train-pipe and chambers 94, 95 open respectively to the augmenting and auxiliary reservoirs D, B by the pipes shown. The valve stem 132 is connected to the diaphragm 96 and has valves 133, 124 normally seated upon apertures in the diaphragm 125 and wall 102. The reservoir D is charged by a permanently open port 134 connecting chambers 93, 94. When trainpipe pressure is reduced both diaphragms 96, 125 fall, and the valve 133 is unseated to connect the reservoir D to the train-pipe. When the trainpipe pressure is raised, the diaphragms are raised to seat the valve 133 and unseat the valve 124, whereby air from the auxiliary reservoir is able to feed past the check valve 100 to the train-pipe. The valve can be made to operate at any desired increase of train-pipe pressure by adjusting the spring of a spring-plunger 123 which bears upon the valve stem 132. When graduated release by the triple valve is desired, the valve F is cut out by valve 117<c>. (4) The auxiliary brake cylinder C<1>, Fig. 3, when employed, can be connected with the brake cylinder C for all operations, by opening cock 129. By closing cock 129 and opening cock 127 to connect it with triple-valve chambers 41, it is charged only in emergency applications. Temporary emergency application can then be obtained by a sudden and brief train-pipe pressure reduction, whereby valve 69 is opened for a short time, and train-pipe-air is admitted by chamber 41 to cylinder C<1> by pipe 126 and to cylinder C by passages 85<a>, 86. The pressure obtained in the cylinders is greater than that obtained by an equal service reduction. The pressure in the cylinder C<1> immediately begins to leak down to atmospheric pressure through passage 61. The pressure in chamber 21, open by passage 22 to chamber 41 also leaks down, causing the abutment 29 and exhaust valve 35 to be raised. The pressure in brake cylinder C thus reduces to the regular service pressure, at which it is held. The regular emergency application takes place as before described, auxiliary-reservoir air being discharged into both cylinders.