Patent ID: 7090773

Claim:
A combination filter for removing particulate matter from engine oil, comprising: a canister, a full flow filter, a bypass filter, a plurality of engine oil inlets, a full flow filter outlet, a bypass filter outlet, and an engine mounting means, the canister comprises a roughly cylindrical shape, closed at one end and open at a second end, the canister closed end possessing a single opening through which the bypass filter outlet passes, the canister open end possessing a plurality of engine oil inlets and an engine mounting means, the full flow filter comprising a cylindrical tube that fits inside the canister, an outer circumferential area existing between the outside of the full flow filter and the inside wall of the canister, the full flow filter sealed to the open end of the canister with gaskets such that oil may enter the open end of the canister and must flow into the outer circumferential area, the full flow filter made of porous material such that oil must flow through the full flow filter from the outer circumferential area through the full flow filter into a transition space, the bypass filter comprising a cylindrical tube smaller in diameter than the full flow filter placed coaxially within the full flow filter in the transition space, the bypass filter sealed at each end of the tube such that oil may pass circumferentially from the transition space through the bypass filter into a bypass collection space, the majority of oil in the transition space exiting the transition space through a full flow filter outlet in the open end of the canister, the full flow filter outlet opening passing through the engine mounting means, the bypass filter possessing a metal cap with a plurality of blades at the end of the bypass filter closest to the canister open end, the metal cap positioned such that if the bypass filter moves towards the canister open end the metal cap will prevent the bypass filter from plugging the full flow filter outlet, the engine mounting means comprising a screw-thread connector that fits internal combustion engine oil filter mounts, the bypass collection space connected via a bypass return orifice to the bypass filter outlet, the bypass return orifice comprising a narrow tube of metal, the bypass return orifice being one (1) millimeter in width, the bypass filter outlet capable of being connected via connectors to a hose which can be lead to any engine oil destination on a internal combustion engine, the oil output of the bypass filter though the bypass filter outlet being a measurable amount which is a function of the amount of oil introduced at the engine oil inlets through a range of engine oil pressures from 5 pounds per square inch to 100 pounds per square inch, the oil output from the bypass filter through the bypass filter outlet never mixes with the oil from the full pass filter until the oil from the bypass filter outlet is returned to the engine at a point other than the engine mounting means.