| 摘要 |
<p>A pressure control valve for controlling the operation of spring-actuated fluid pressure released brake units in vehicle braking systems. The valve described requires less operating effort than for conventional control valves of this kind even those including a follow-up means. It has a plunger-type valve element slidable within the carrier and controlling the flow of fluid between inlet and delivery ports. The carrier is biassed towards an open position of the valve in opposition to a spring force by the delivery pressure and the valve element is responsive to delivery pressure to open the valve in opposition to another spring force. The carrier spring has a substantially greater rate than the valve element spring which can be adjusted so that the effort required to operate the valve can be kept to moderate limits while retaining the advantage of a follow-up valve action.</p> |
