Patent GB-190405070-A (GB)
Title: Improvements in Fluid Pressure Brake Apparatus for Railway and like Vehicles.
Inventor: ORLOFF MICHAEL EUGENE
Filed: 1904-03-01
Granted: 1904-12-31
Abstract: 5070. Orloff, M. E. March 1. Brakes.-A graduated release for fluid-pressure brakes is obtained by exhausting the fluid successively into a series of chambers 11 to 15, Fig. 1, it being exhausted into the atmosphere for full release only. The invention is described with reference to the single-chambered type of brake. A cylinder 1 is connected at 17 to the train-pipe of the brake, and has a piston 2 which carries a slide valve 3, Figs. 1 and 2, an aperture 19 in which is long enough to uncover all the ports 4 to 10 in the cylinder facing at one time. The passage 4 is connected with the exhaust port of the triple valve of the brake cylinder, and the passage 10 with the atmosphere. When the brakes are fully applied, the piston 2 is in the position shown. In releasing the brakes, as the pressure in the train-pipe is increased, the piston and valve move to the right, and open communication with the brake-cylinder exhaust at 4, and one or more of the chambers 11, 12, &c. by ports 5, 6, &c., and so a partial release is obtained according to the amount of increase of pressure in the train-pipe. When the brakes are fully released, the valve uncovers all the ports 4 to 10, so that the exhaust from 4 and from the chambers passes into the atmosphere by the port 10. The piston has now come to that part of the cylinder in which a groove 18 is made through which air passes, thus equalizing the pressures on each side of the piston. To apply the brakes, the pressure in the train-pipe is diminished, whereby the piston is made to move to the left again. A spring 20, shown in dotted lines, may be used to cause the piston to move back, instead of the leakage groove 18, in which case an opening 21 to the atmosphere is provided. Pressure-retaining valves actuated by weights or springs may be connected with some or all of the chambers 11, 12, &c., or direct to the ports 5 to 9. In a modified slide valve, Fig. 3, the ports 5 to 10 are arranged as shown, and the aperture 19 is made T-shaped. Other apertures 22, 23, 24, and another atmospheric port 16, are also provided. As the valve moves to the right, not only is communication made between the port 4 and ports 5, 6, &c. successively, but, when the port 4 is in communication with the port 6, the aperture 22 connects the port 5 to the atmosphere, and so on with the other ports. In this way, as communication is made between one of the chambers 11, 12, &c., Fig. 1, and the exhaust, the preceding chamber is connected to the atmosphere. In a modification, Fig. 4, separate chambers are replaced by a valve 103 actuated by another piston 102 working in a cylinder 101, which is connected direct to the brake cylinder by the aperture 117, and has a port 116 open to the atmosphere. The pistons are in the position shown when the brakes are fully applied. In releasing the brakes, as the port 5 is uncovered, the exhaust passes to the aperture 191 of the valve 103, and thenca to the atmosphere by the port 116. The consequent decrease in pressure in the brake cylinder causes the piston 102 to move towards the right, and the valve 103 to cut off the escape of the exhaust from the port 5 and stop the fall in pressure in the brake cylinder. Owing to the equalization of pressure on the two sides of the piston 102, caused by a groove 118, the piston also is stopped, and therefore a partial release of the brakes is obtained. As the trainpipe pressure is increased, ports 6, 7, &c. are uncovered, and further release obtained as before. When the brakes are applied, the piston 102 moves back again due to the admission of air under pressure from the brake cylinder.