Patent GB-118078-A (GB)
IPC: B60T13/36
Abstract: 118,078. Automatic Straight Air Brake Co., (Assignees of Neal, S. G.). Aug. 1, 1917, [Convention date]. Fluid-pressure. - Relates to brake apparatus, particularly of the kind described in Specifications 100,636 and 116,728, wherein the brake cylinders are supplied by the train-pipe augmented by service reservoirs in service applications and by auxiliary reservoirs in emergency applications. The present construction provides means by which (a) quick release of the brakes is obtained by connecting the auxiliary reservoirs to the train-pipe upon raising the train-pipe pressure, (b) the service reservoirs are cut off from the train-pipe in emergency applications and the air therein used to effect the connexion of the auxiliary reservoirs and of the service reservoirs themselves with the brake cylinders, and (c) the train-pipe is vented to atmosphere in emergency applications. An auxiliary brake cylinder may be so connected as to be operative in all applications of the brakes or in emergency applications only. The apparatus includes the triple valve section, Fig. 2, comprising the parts for obtaining service applications and release including the quick-release means, the triple valve section B containing the parts controlling emergency applications and for cutting- off the service reservoir E from the train-pipe and for connecting it to the brake cylinder, the auxiliary reservoir C, the main brake cylinder D, and the auxiliary brake cylinder D<1>. The train-pipe is connected to the chamber 2, Fig. 2, the auxiliary reservoir to the chamber 4 and the brake cylinder to the chamber 25. The means for charging the auxiliary reservoir from the trainpipe through the chambers 2 and 4 and valve 9; for supplying the brake cylinder in service applications through the chamber 2, stem 6, valve 32, and chamber 25; and for exhausting the brake cylinder through the chamber 25, valve 35, and passage 36 are substantially the same as described in the above-mentioned Specifications and in Specification 121,151. The means for accelerating the release of the brakes comprises a lever 62 pivoted at 62<a> and connected to a diaphragm 43 and to valves 71 and 55. The chamber 40<a> beneath the diaphragm 43 is open to the train-pipe by passage 42 and chamber 2. Chamber 47 above this diaphragm is normally connected to the service reservoir E through the passage 61, chamber 52, and pipe 59. Upon an increase in train-pipe pressure, the diaphragm 43 is raised against the pressure of the springs 56 and 72, first opening the valve 71 to admit air to the train-pipe from the auxiliary reservoirs, by way of the chamber 4, the check valve 77, pipe 68, valve 71, and chamber 2. The valve 55 also is opened, but its actuation is delayed, by the play allowed to the lever 62 in the slot in the valve 55, until the auxiliary reservoir has discharged into the chamber 40<a>. Opening of the valve 55 permits charging of the service reservoir E by way of the pipe 59. In service applications, service reservoir air feeds past the valve 55 to the chambers 40<a>, and thence to the brake cylinder. The quick release means can be rendered inoperative by a cock 80, Fig. 1, in the pipe 68. The triple-valve section B comprises chambers 81 and 39<a> separated by a diaphragm 63 engaging a lever 85 which actuates, with slight lost motion, a vent valve 88 opening to atmosphere. The chamber 39<a> is connected to the train-pipe at 1<a>. The diaphragm 63 is also connected to a lever 95 which actuates a stem 97 carrying a valve 111 controlling communication of the pipe 59 with chamber 81 and a double valve 99, 100 controlling the connexion of the service reservoir E with the chamber 81 and the chamber 41. Chambers 81 and 41 are separated by a diaphragm 39 to which is secured a yoke 116 for actuating a valve 51 controlling a passage 61 leading from the chamber 41 to atmosphere. The yoke is also attached by the bar 118 to valves 60, 60<a> which respectively control the connexion of the chamber 41 with the auxiliary reservoir by way of chamber 2, Fig. 2, and pipe 121, and with the brake cylinder by pipe 123 and chamber 25. To effect the proper timing of the valves, the levers 85, 95 have play in the valve stems 87, 97. In charging the apparatus, train-pipe air is supplied through the chamber 2 and the valve 55, Fig. 2, as described above, is led by the pipe 59 into the chamber 81 and small reservoir F connected thereto at f and past the valve 99 into the service reservoir E. The valves 100, 60, 60<a> are closed at this time and the valve 51 is open so that chamber 41 is vented. In service applications, the valves 111. 99 remain open to permit the supply of air from the service reservoir through the valve section, Fig. 2, to the brake cylinder. Upon an emergency train.pipe pressure reduction, the pressure in chamber 39<a> is correspondingly reduced and the superior pressure in chamber 81 depresses the diaphragm 63 immediately closing valves 99 and 111 and opening valve 100 and then opening valve 88 to vent the train-pipe to atmosphere. The service reservoir air now enters the chamber 41 past the valve 100 and check valve 107 and depresses the diaphragm 39 whereby the vent valve 51 is closed and the valves 60, 60<a> are opened to connect the auxiliary reservoir C to the brake cylinder D by way of chamber 4, Fig. 2, pipes 68, 121, 123, and chamber 25. The service reservoir air can also flow into the brake cylinder through the valve 60a. Valve 111 has a leak port 112, and, when the pressure in chamber 81 has equalized thereby with pressure in chamber 39<a>, the diaphragm 63 is raised by springs 84, 91 sufficiently to close the vent valve 88. Complete return of the diaphragm 63 is prevented at this time by abutting against a stop 128 on the diaphragm 39. Upon increasing the trainpipe pressure, the exhaust valve 35, Fig. 2, is opened and the pressure in the brake cylinder and in the chamber 41 is released and the diaphragm 63 then completes its upward movement and the diaphragm 39 also is raised whereby the valves are returned to normal position. The chamber 21, Fig. 2, is open to atmosphere by port 22 and as, after an emergency application, the pressure in chambers 4 and 25 are equal, it is only necessary to build up a moderate pressure in the chamber 2 dependent upon the relative areas of diaphragms 3 and 24 to release the brakes. The auxiliary brake cylinder D<1> has a connexion 124 with the chamber 41, Fig. 3, and a connexion 126 with the main brake cylinder D. With the cock 127 closed and the cock 125 open, the cylinder D is operative only in emergency applications. With the cock 127 open and the cock 125 closed this cylinder is operative in all applications.