GB925643A - Improvements in or relating to vacuum brake installations - Google Patents

Abstract

925,643. Vacuum braking systems. KNORR-BREMSE G.m.b.H. March 15, 1960 [March 17, 1959], No. 9156/60. Class 103 (1). A vacuum brake installation for rail vehicles, comprises a brake cylinder 9 divided into chambers 7, 35 by a piston connected to operate the brakes, and a valve device 13 for connecting chambers 7, 35 during brake release, an additional valve 41, controlled by piston 49 acted on in the valve closing direction by a spring 49 and pressure in chamber 35, being connected into the pipe between chambers 7, 35. With normal vacuum in train pipe 1, the valve 27, 29 in valve 13 is closed by a spring and valve 53, 57 in valve 41 is opened by atmospheric pressure above piston 49; the whole installation being evacuated via pipe 19, one-way valve 45 and throttle 3. On braking, the rise in train pipe pressure, acts via valve 5 in chamber 7 to apply the brakes, the equal pressures in chambers 11, 17 of valve 13 preventing opening of valve 27, 29. On brake release, vacuum in train pipe 1 acts via pipe 19 in chamber 17 to raise piston 15 and open valve 27, 29 to connect the brake cylinder chambers 7, 35 via chambers 25, 31, 55, 37 for rapid release. The installation then slowly evacuating via throttles 3, 43 and one-way valve 45. After repeated applications and releases in quick succession, the pressure in chamber 35 and reservoir rises until at a predetermined value this pressure and spring 47 raises piston 49 to close valve 57, 53, chamber 7 now being exhausted via throttle 3; normal brake release only occurs when the pressure in reservoir 33 and chambers 35 has dropped below that value when valve 53, 57 opens. This ensures that sufficient vacuum exists in chamber 35 for brake application.