Patent ID: 7390407

Claim:
A liquid filter comprising: a housing having an inlet and an outlet, said housing comprising a housing pot with a substantially downwardly open filter element installation opening and a screw-on cover that closes the installation opening, said screw-on cover having a drain for discharging residual liquid present in the housing, a filter element arranged in the housing sealingly separating the inlet from the outlet, said filter element including a filter medium and having two axial ends with one of said axial ends proximate the screw-on cover having a substantially closed end disk bonded to the filter medium, and a device arranged in the area of said drain for opening and closing said drain; wherein said drain comprises a round drain opening arranged on the central axis of the housing, and the device for opening and closing the drain is connected to the substantially closed end disk of the filter element with limited axial play so the device can move a limited distance axially relative to the filter element, and the device is displaced axially relative to the drain opening to open the drain opening when said screw-on cover is unscrewed.