Patent ID: 7204370

Claim:
A filter element including a ring of filtration media circumscribing a central axis and having first and second ends; an end cap assembly at the first end of the filter media including i) a first flat annular end cap sealingly bonded to the first end of the filtration media, and a separate annular end piece located in sealing relation with the first end cap; and a second flat annular end cap sealingly bonded to the second end of the filtration media; the second end cap including a central opening along the central axis of the filter element; said end cap assembly at the first end of the filter element including a central opening along the central axis of the filter element, said central opening of said end cap assembly having a smaller diameter than said central opening of said second end cap, and being defined by an annular flange integral with an inner surface of said end cap assembly and extending axially inward from said end cap assembly toward said second end cap and terminating at a point closer to said end cap assembly than said second end cap, said annular flange spaced radially inward from the ring of filtration media; and a series of axially-extending protrusions affixed to said annular end piece of the end cap assembly radially between said flange and said ring of filtration media, said protrusions extending axially inward from said end cap assembly toward said second end cap and terminating at a point closer to said end cap assembly than said second end cap.