| 摘要 |
A quick service valve is proposed for providing continuous quick service in connection with the operation of a direct release triple valve preferably also provided with an emergency portion having a sensitivity valve for providing a bleed of fluid pressure from a quick action chamber to follow the pressure reductions in a brake pipe, the apparatus having a reference pressure input path connected to the quick service chamber, a brake pipe pressure signal input path, a pressure responsive member responsive to a predetermined difference between the brake pipe pressure and the reference pressure to operate a valve to initiate a restricted discharge from the brake pipe to cause a reduction of the reference pressure and consequent reclosure of the valve. The operation is repetitive during continuing reduction of brake pipe pressure at sufficient rate. |
