Filter assembly with modulating bypass valve
AssigneeCaterpillar Tractor Co.
InventorLarry W. Lorimor
Life of this patent
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Abstract
A filter assembly comprises a housing having a tubular filter and a bypass valve mounted therein. The valve comprises a spool having pressure modulating means thereon in the form of a tubular extension having a plurality of metering orifices formed therethrough. In normal operation, fluid is communicated from an inlet of the housing, through the filter and to an outlet. When the inlet pressure of the fluid exceeds a predetermined level due to clogging of the filter, for example, the fluid is communicated from the inlet to the outlet directly, through the metering orifices of the valve. The spool has a cylindrical portion which forms a sliding seal with a cylindrical bore defined in the housing to prevent premature opening of the bypass valve.
Claims15
In a filter assembly of the type comprising a housing having an inlet and an outlet, a filter mounted in said housing and bypass valve means movable between a closed position for sequentially permitting communication of fluid from said inlet, through said filter and to said outlet and an open position for sequentially communicating fluid from said inlet, through a port of said bypass valve means and to said outlet, the improvement wherein said bypass valve means comprises a reciprocally mounted spool and pressure modulating means secured to said spool, comprising a tubular extension formed on an upper end of said spool having a plurality of metering orifices formed therethrough and continuously exposed to fluid from said inlet, for simultaneous movement therewith for modulating the pressure of said fluid through said bypass valve means upon opening thereof by metering fluid directly through said orifices, through said port and to said outlet to contol variable differential fluid pressures prevalent on downstream and upstream sides thereof.
In a filter assembly of the type comprising a housing having an inlet and an outlet, a filter mounted in said housing and bypass valve means movable between a closed position for sequentially permitting communication of fluid from said inlet, through said filter and to said outlet and an open position for sequentially communicating fluid from said inlet, through a port of said bypass valve means and to said outlet, the improvement wherein said bypass valve means comprises a cylindrical spool having a cylindrical portion thereof closely fitted for reciprocation in a cylindrical bore defined in said housing to define said port and to further define a sliding seal thereat normally closing said bypass valve means for preventing premature opening thereof when said bypass valve means is subjected to pressure pulsations and a tubular extension formed on an upper end of said spool having a plurality of metering orifices formed therethrough to comprise said bypass valve means for communicating bypassed fluid directly through said orifices, through said port and to said outlet and to receive fluid from said inlet directly, said orifices continuously exposed to fluid from said inlet during both the closed and open positions of said bypass valve means.
Dependencies are inferred from the claim text.