| 摘要 |
<p>A valve for preventing the loss of fluid from a fluid circuit in an engine block when a screw on filter element located at a low point in the circuit is removed includes a bore in the engine block having an inlet passage connected to the bore near a valve seat which connects the bore to the outside of the engine block. The bore contains a poppet valve having a threaded end for engaging the filter element and a pin and spring combination passing through a longitudinal slot in the poppet valve to cause the poppet valve to block the bore to prevent the loss of fluid. The poppet valve is hollow and open to an outlet passage in the engine block which is spaced away from and is always blocked from the inlet passage. The through passage has a check surface and contains a check ball and check spring which are disposed between the pin and the threaded end of the poppet valve. The check spring has a free height which causes it to act to prevent the flow of fluid from the outlet passage when the bore is blocked by the poppet valve but allow the flow when the bore is unblocked. The poppet valve is opened by screwing on the filter element which allows fluid to enter the inlet of the filter element. After the fluid is filtered the fluid exits from the filter element through a center outlet and past the check ball and out the outlet passage.</p> |
