| 摘要 |
PCT No. PCT/DE80/00170 Sec. 371 Date Jul. 8, 1981 Sec. 102(e) Date Jul. 8, 1981 PCT Filed Nov. 12, 1980 PCT Pub. No. WO81/01393 PCT Pub. Date May 28, 1981.A service brake accelerator for indirect compressed-air brakes on railway vehicles includes a control piston which is loaded by the pressure in the main airpipe against the pressure in a reference pressure chamber and which controls a shutoff valve between the main airpipe and a piston chamber, a first outlet valve for the main airpipe and a second outlet valve for the piston chamber. Through appropriate dimensioning of the valve strokes (a,b), upon movement of the control piston out of its rest position the shutoff valve is closed first, and simultaneously or later the first outlet valve is opened and only subsequently the second outlet valve is opened. A valve piston arranged coaxially with the control piston is loaded by the pressure in the piston chamber and the force of a spring. On its other side, the valve piston is acted upon by the reference pressure over a partial area, but with the air vent valve open it is acted upon by the reference pressure over its entire area. When the piston chamber is vented, and after opening of the air vent valve, the valve piston rests against a valve stem connected to the control piston, thereby equalizing changes in loading with respect to the control piston. |
