Abstract: An oil filter includes a housing 14 having an end plate 20 attached to the open end thereof. The end plate 20 includes an outlet opening and inlet openings 22. An anti-drainback valve 49 is provided adjacent the end plate. A filter element having an end cap at each end is positioned within the housing. The end cap 50 remote from the end plate includes a plurality of openings 52 spaced from a closed central portion 51. A spring valve 60 cooperates with the end cap 50 and the interior wall of the housing to alternately allow and disallow oil flow through the end cap openings depending upon the differential pressure across the end cap 50. The spring valve 60 and the end cap 50 can be operationally interengage to provide a relatively flat profile. Depressions 72 (FIG. 5) may be included between the arms 62 of the spring valve to provide a flow path should the spring valve be flattened against the housing during operation of the filter.

Abstract: An oil filter comprises a housing that is open at one end and has an end plate connected to the housing for closing the open end. The end plate has at least one inlet opening and an outlet opening therein. An anti-drain back valve is provided for precluding return flow of oil through the inlet opening. An annular filter media is disposed in said housing. An end cap is provided at each end of the filter media. The end cap remote from the end plate has at least one opening spaced radially outwardly from the central axis thereof. A spring cooperates with said end cap remote from the end plate. Normally, the opening in the spring is closed to oil flow. When the filter media becomes clogged, the pressure within the housing increases and when the pressure differential across the end cap remote from the end plate exceeds a predetermined value, the opening in the spring is opened for oil flow.