Integrated PCV valve and oil filler cap

Claim 1

An oil filler cap integrated with a positive crankcase ventilation (PCV) valve assembly for use with an automotive type internal combustion engine having an air cleaner assembly for the supply of clean air to a carburetor induction passage connected to the intake manifold of the engine, comprising: a hollow-closed one-piece housing adapted to be inserted into the inlet of a tube projecting from the engine through which oil may be added to the engine and through which crankcase vapors from the engine may flow out of the engine into the housing, the housing having first means connecting the inlet tube to the engine intake manifold for the flow of crankcase vapors normally therebetween below a predetermined flow pressure level, the housing having second means connecting the air cleaner assembly to the engine crankcase for the flow of clean air to the crankcase at pressures higher than the intake manifold below the said predetermined flow pressure level, the housing having further means operable above the predetermined flow pressure level to connect the crankcase vapors to the air cleaner in parallel flow arrangement with the flow of vapors to the intake manifold, the first means including a cylindrical filter member open at opposite ends and adapted to have one end insertable into the inlet of the tube to receive crankcase vapors therefrom, the further means comprising a first one-way check valve closing the opposite end, first conduit means connecting the crankcase vapors through the filter member directly to the intake manifold at all times bypassing the check valve, the second means including a second conduit in side-by-side relationship to the filter member and a cover common to the filter member and second conduit and defining a chamber in the housing having a first connection to the filter through the first check valve end of the filter past the first check valve in an open condition, the chamber having a second connection to the crankcase through the second conduit past a second check valve comprising means including a spring closed valve means openable by pressure thereagainst in the chamber at a greater pressure level than in the crankcase, the chamber having additional conduit means connecting the chamber to the air cleaner assembly whereby flow of crankcase vapors below a first predetermined rate effects flow through the filter only into the intake manifold with the first check valve closed and the second check valve opened by the flow of air from the air cleaner to the crankcase and whereby flow of crankcase vapors above a predetermined rate effects opening of the first check valve for the simultaneous flow of vapors into the air cleaner assembly as well as the intake manifold and the closing of the second check valve by the equalization of the pressure level of the vapors acting on opposite sides of the valve means.