Filter assembly having a two-way bypass valve therein

Claim 2

An oil filter comprising, in combination, a filter bowl, a closure member having oil-flow passages therein opening to and from the bowl interior, and a filter element operatively mounted in the bowl in the normal path of oil flow between said passages and including a perforated-wall center tube and an annular body of filtering media extending thereabout, and a two-way bypass valve unit mounted in fixed position within and at one end of said center tube and thus in the path of oil flowing in either axial direction therethrough and being operative to permit oil entering the bowl through either one of said passages and leaving through the other passage to bypass the filtering media of the filter element upon the pressure of oil within the bowl exceeding a predetermined safe pressure, said unit comprising a cup-shaped shell having a press fit in said center tube the end wall of said shell having centrally disposed and at least one radiallyinwardly disposed oil-flow through openings, a valve disc normally seating on the relatively under fAce of said end wall and adapted to close only said centrally disposed opening, a valve annulus normally seating against the relatively inner face of said end wall and adapted to close only said radiallyoutwardly disposed opening, and means serving simultaneously to bias both said valve disc and valve annulus to their respective seated positions while permitting movement of either but not both to an unseated position as permits oil flow through either but not both said central opening and said radially-outwardly disposed opening, said biasing means comprising a cross strap member extending diameter-wise across the interior of said shell and having slide fit on the sidewall surface thereof, said valve disc and cross strap member being loosely connected by a pin extending axially through said central opening, and a coil spring interposed between and reactive against said valve annulus and the cross strap member and imparting spring bias in seating direction on said valve disc via said member and pin and further imparting spring bias in seating direction on said valve annulus by its direct engagement therewith, the construction and arrangement of said two-way bypass valve unit being thus such as makes immaterial which of said oil-flow passages in said bowl closure member provides the oil inlet passage to the bowl interior and which the oil outlet passage therefrom.

Claim 3

An oil filter element comprising spaced inner and outer annular perforated-wall screen members, and caps permanently affixed to the opposite ends of said screen member, a pleated-paper filter media contained within the annular space between said screen members and being edge-sealed to the inner surfaces of said end caps, and a two-way bypass valve unit mounted in fixed position in and at one end of said inner tubular screen member and including a cup-shaped shell having press fit in said inner screen member, the end wall of said shell having a centrally disposed and at least one radially-outwardly disposed through opening therein, a valve disc normally seating on the relatively under face of said shell end wall and adapted to close only said central opening, a valve annulus normally seating against the relatively inner face of said end wall and adapted to close only the radially-outwardly disposed opening, and means serving simultaneously to bias both said valve disc and valve annulus to their respective seated positions while permitting movement of either but not both to an unseated position, said biasing means comprising a cross strap member extending diameter-wise across the interior of said shell and having slide fit on the sidewall surface thereof, said valve disc and cross strap member being loosely connected by a pin extending axially through said central opening and said valve annulus, and a coil spring interposed between and reactive against the valve annulus and said cross strap member, said spring imparting spring bias in seating direction on said disc valve via said member and pin and further imparting spring bias in seating direction on said valve annulus by its direct engagement therewith, the construction and arrangement being such that said valve unit is operative to permit oil which would normally be filtered by its passage through said filter media in either direction to bypass same upon the pressure of said oil exceeding a predetermined safe pressure.

Claim 4

An oil filter element comprising spaced inner and outer annular perforated-wall screen members, and caps permanently affixed to the opposite ends of said screen member, a pleated-paper filter media contained within the annular space between said screen members and being edge-sealed to the inner surfaces of said end caps, and a two-way bypass valve unit mounted in fixed position in and at one end of said inner tubular screen member and including a cup-shaped shell having press fit in said inner screen member, the end wall of said shell having a centrally disposed and at least one radially-outwardly disposed through opening therein, a valve disc normally seating on the relatively under face of said shell end wall and adapted to close only said central opening, a valve annulus normally seating against the relatively inner face of said end wall and adapted to close only the radially-outwardly disposed opening, and means serving simultaneously to bias both said valve disc and valve annulus to their respective seated positions while permitting movement of either but not both to an unseated position, said biasing means comprising a cross strap member extending diameter-wise across the interior of said shell and having slide fit on the sidewall surface thereof, said valve disc and cross strap member being loosely connected by a pin extending axially through said central opening and said valve annulus, and a coil spring interposed between and reactive against the valve annulus and said cross strap member, said spring imparting spring bias in seating direction on said disc valve via said member and pin and further imparting spring bias in seating direction on said valve annulus by its direct engagement therewith, the construction and arrangement being such that said valve unit is operative to permit oil which would normally be filtered by its passage through said filter media in either direction to bypass same upon the pressure of said oil exceeding a predetermined safe pressure.

Claim 5

A full-flow oil filter comprising: an open top, generally cylindrical filter bowl and a head member affixed in top-closing relation to the bowl and having oil-inlet and oil-outflow passages provided therein, of which one said passage terminates at its relatively inner end in a passage portion which opens to the bowl interior on the bowl axis and the other said passages terminates at its relatively inner end in a passage portion which also opens to the bowl interior but is disposed radially-outwardly from said bowl axis; an annular filter element disposed in said closed-top bowl comprising inner and outer tubular screens, imperforate end caps affIxed to the opposite ends of said screens and oil filtering media filling the annular space between said screens; means mounting said filter element in coaxial relation within the filter bowl and including means forming a sealed oil-flow path extending between said axial passage portion and the proximal end of the inner tubular screen of the filter element whereas said other passage portion is at all times in full open communication with the interior space of the filter bowl extending about and to the ends of said filter element; and a two-way bypass valve unit mounted within said inner tubular screen at its distal end and being operative when the pressure of the oil is within safe limits positively to close off said distal end to oil flow therethrough in either direction; whereby oil entering the filter through said axial passage portion then operating as the filter oil-inlet is constrained to flow directly to said proximal end of and thence axially along said inner screen and thence radially-outwardly through the filtering media to said other passage portion, and whereby oil entering the filter through said other passage portion then operating as the filter oil-inlet is constrained to flow radially-inwardly through said filtering media and thence outwardly from the filter through said inner screen and said axial passage portion; and said bypass valve unit being further operative, upon a buildup of the pressure of the oil entering the filter through said axial passage portion beyond a predetermined safe limit, to open said distal end of the inner screen to oil flow therethrough in one direction as results in said oil bypassing the filtering medium and following a flow path extending directly to said other passage portion and, conversely, upon the pressure of the oil entering the filter through said other passage portion building up beyond the predetermined safe limit, to open said distal end of the inner screen to oil flow therethrough in the opposite direction as results in said oil bypassing the filtering medium and following an outflow path from the filter interior defined by the bore of said inner screen and said axial passage portion.

Claim 6

A full-flow oil filter comprising: an open top, generally cylindrical filter bowl and a head member affixed in top-closing relation to the bowl and having oil-inlet and oil-outflow passages provided therein, of which one said passage terminates at its relatively inner end in a passage portion which opens to the bowl interior on the bowl axis and the other said passages terminates at its relatively inner end in a passage portion which also opens to the bowl interior but is disposed radially-outwardly from said bowl axis; an annular filter element disposed in said closed-top bowl comprising inner and outer tubular screens, imperforate end caps affIxed to the opposite ends of said screens and oil filtering media filling the annular space between said screens; means mounting said filter element in coaxial relation within the filter bowl and including means forming a sealed oil-flow path extending between said axial passage portion and the proximal end of the inner tubular screen of the filter element whereas said other passage portion is at all times in full open communication with the interior space of the filter bowl extending about and to the ends of said filter element; and a two-way bypass valve unit mounted within said inner tubular screen at its distal end and being operative when the pressure of the oil is within safe limits positively to close off said distal end to oil flow therethrough in either direction; whereby oil entering the filter through said axial passage portion then operating as the filter oil-inlet is constrained to flow directly to said proximal end of and thence axially along said inner screen and thence radially-outwardly through the filtering media to said other passage portion, and whereby oil entering the filter through said other passage portion then operating as the filter oil-inlet is constrained to flow radially-inwardly through said filtering media and thence outwardly from the filter through said inner screen and said axial passage portion; and said bypass valve unit being further operative, upon a buildup of the pressure of the oil entering the filter through said axial passage portion beyond a predetermined safe limit, to open said distal end of the inner screen to oil flow therethrough in one direction as results in said oil bypassing the filtering medium and following a flow path extending directly to said other passage portion and, conversely, upon the pressure of the oil entering the filter through said other passage portion building up beyond the predetermined safe limit, to open said distal end of the inner screen to oil flow therethrough in the opposite direction as results in said oil bypassing the filtering medium and following an outflow path from the filter interior defined by the bore of said inner screen and said axial passage portion.

Claim 7

A full-flow oil filter according to claim 3, wherein said two-way bypass valve unit includes a generally circular wall member extending transversely across the bore of said inner tubular screen and in the path of oil flow in either direction therethrough, said wall member having centrally disposed and at least one radially-outwardly disposed oil-flow through openings, separate valve elements seating against the opposite faces of said circular wall, of which one said element is adapted to close only said central opening and the other element is adapted to close only said radially-outwardly disposed opening, and spring means common to the said valve elements serving to bias both said elements to their respective seated positions while permitting movement of either, but not both simultaneously, to an unseated position, as permits oil flow through either, but not both simultaneously, said central opening or said radially-outwardly disposed opening.

Claim 8

A full-flow oil filter according to claim 3, wherein said two-way bypass valve unit comprises an inverted cup-shaped shell having its sidewall affixed to the inner surface of said inner screen, the end wall of said shell having a centrally disposed and at least one radially-outwardly disposed through openings therein, a valve disc disposed to seat on the relatively under face of the shell and endwall and adapted when seated to close said central opening, a valve annulus disposed to seat on the relatively inner face of said shell endwall and adapted when seated to close the radially-outwardly disposed opening, and means common to both said valve disc and valve annulus for biasing same simultaneously to their respective seated positions, while permitting movement of either, but not both simultaneously, to its unseated position.