Filter unit

Claim 1

A spin-on throwaway oil filter for mounting on a base extending from a vehicle engine, comprising a cylindrical casing with a closure member closing off one end and having a central opening with a threaded bushing extending from said opening to thread it onto the base and discharge oil therefrom, oil inlet means in said closure member around said bushing, sleeve means in said casing around said central opening, a filter element disposed in said casing between said oil inlet means and bushing and seated on said sleeve, said filter element having a center tube therein, a standpipe extending upwardly a substantial distance into said center tube and in communication with said bushing to discharge oil thereto, and gasket means extending below said closure member to enable said casing to be secured to the base in an oil tight relationship, said standpipe having a substantially smaller diameter than said center tube to provide an annular flow chamber around the standpipe, said bushing being secured to said closure member adjacent said central opening and the lower end of said standpipe being secured to the upper end of the said bushing which has a portion extending upwardly into said center tube, said sleeve means having an annular resilient gasket and leaf spring member disposed thereon forming a check valve covering said oil inlet means, said gasket means being annular and seated in a retainer plate having a vertical elongated wall adjacent its inner circumference and a horizontal wall outwardly of the vertical wall, said retainer plate having a rolled over lip forming a seam with a compementary rolled over lip on the lower periphery of the casing and said plate lip forming a short vertical wall outwardly of said horizontal wall, said sleeve means being provided with a bypass valve and including a sleeve housing surrounding said standpipe with a horizontal annular member with oil bypass ports therein, an annular valve disc seated over said ports, biasing means enclosed in said housing normally maintaining said disc seated, and an annular oil bypass discharge port in said housing surrounding said standpipe and in communication with said annular flow chamber.