Patent ID: 7754069

Claim:
A filter for trapping foreign matter comprising: an inflow chamber into which a fluid flows; an outflow chamber from which flows the fluid that has flown into said inflow chamber; and a filter element, occupying an annular space surrounding a hollow portion, and having an outer curved surface, end surfaces and an inner curved surface defining the hollow portion, said filter element partitioning said two chambers, wherein said inflow chamber has a structure arranged substantially the entire length of the inflow chamber and comprising a flow guide being substantially conical with its diameter increasing in the direction of the fluid flow, and extending from the lower end of the inflow chamber to a position near the top of the inflow chamber, such that substantially all the fluid that flows into said inflow chamber is spouted up from a bottom portion of said inflow chamber in a rising flow that is forcibly directed radially by said structure toward said inner curved surface of said filter element along substantially the entire length of said filter element to fall upon and enter the filter element at said inner curved surface.