Abstract: A filter assembly for an internal combustion engine includes inner and outer coaxial filter elements disposed in a spin-on canister which is detachably secured to a mounting adaptor. Oil from the crankcase is filtered by the outer filter element and a substantial volume of the filtered oil flows to the primary lubricating circuit of the engine. A small percentage of the filtered oil is subjected to further filtration by the inner filter element and is returned directly to the crankcase. A tubular fitting extends between end caps on the two coaxial filter elements to establish communication between the inner filter and the mounting adaptor, to separate the two flow circuits, and to maintain a fixed axial spacing between the two filter elements.

Abstract: An elastomeric valve member coacts with a valve seat and an apertured plate to control the flow of oil between the inlet and outlet of an oil filter for an internal combustion engine. When the engine is shut down, the valve member seals against both the valve seat and the plate to hold oil in the filter and prevent such oil from returning to the crankcase via the inlet. Under normal running conditions, the valve member unseals with respect to the plate to permit oil to flow between the inlet and outlet by way of the filter element of the filter. If the pressure differential between the inlet and the outlet exceeds a predetermined value, the valve member unseals with respect to the valve seat to enable the oil to bypass the filter element and to flow directly from the inlet to the outlet.

Abstract: The valve includes a valve member adapted to be moved axially between open and closed positions in a valve housing when the valve member is rotated. The valve member includes a passage for admitting air into a vacuumized vessel and includes a separate passage for draining liquid from the vessel when the valve member is in its open position. An O-ring establishes a primary seal between the valve member and the valve housing and is retained within the housing in all positions of the valve member.