Patent ID: 6837993

Claim:
A filter assembly including a filter element and a filter housing, said filter housing having a sidewall, a closed end and an open end, and including: a central support core fixed to the closed end of the housing and extending toward the open end of the housing, said central support core including an internal annular step along the length of the core; an extension and locking assembly slidingly disposed within said support core, said extension and locking assembly including a bypass member closely received within the support core, and a locking member closely received within the bypass member, and positioned to urge a distal inner end of the bypass member radially outward into engagement with the support core; a main spring biasing said extension and locking assembly axially outward from the support core, wherein said extension and locking assembly is normally in an position outward from said support core when the filter element is absent from the filter housing, with said bypass member engaging the internal step on the support core to maintain the extension and locking assembly in the outer position, and said locking member is moveable relative to the bypass member to a position where the locking member allows the bypass member to disengage from the internal step and allow the extension and locking assembly to be moved inwardly into the support core into an inner position, when the filter element is located in the filter housing.