US 4,786,409 AGranted

Duplex filter assembly

AssigneeParker-Hannifin Corporation

InventorDaniel W. Miller

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Abstract

Duplex filter apparatus suitable for pressure or suction applications includes dual filter housings and a central valve housing having dual, cylindrical, three-way plug valves. Four glass-filled Teflon sleeve seals, each having an inner cylindrical cut edge conform to the valve periphery and seal the valve openings in either a pressure or suction configuration. A wave spring biases each sleeve seal against the plug valve and further o-ring seals utilize the pressure or suction condition to enhance the effectiveness of the sleeve seals. In the pressure configuration a tubular support is used in conjunction with the sleeve seal with the wave spring acting either directly on the sleeve seal or indirectly through an intermediate metal ring which houses the o-ring seals and which minimizes thermal expansion effects. Interlock mechanisms are associated with a handle which rotates the plug valve between off-duty and on-duty filter housings to assure that the filter housing cover cannot be opened while on-duty, nor that the valve can be turned without the off-duty housing prepared for fluid. The interlock mechanisms comprise mechanical detents and levers interconnected with the handle and the filter housing covers.

Claims11

Dependent claims

Duplex filter apparatus, comprising

a valve housing with a vertical central bore having an inlet port, an outlet port, a pair of inlet openings communicable with said inlet port and a pair of outlet openings communicable with said outlet port, said inlet and outlet openings comprising short transverse bores in said valve housing,
a pair of filter element housings each having an element inlet port and an element outlet port in fluid communication with said inlet and outlet openings of said valve housing,
a filter element disposed in each element housing between said respective element inlet and outlet ports,
a cylindrical plug valve in said housing central bore, said plug valve having respective upper and lower cylindrical peripheral sealing surfaces surrounding respective upper and lower chambers and having respective upper valve inlets and upper valve outlet and lower valve inlet and lower valve outlets, said plug valve being rotatable in said housing bore to alternatiely dispose said valve inlets and outlets in fluid communication with said housing inlet and outlet ports for alternate fluild flow through said filter elements, said peripheral sealing surfaces being positioned adjacent said respective housing inlet and outlet openings, and
tubular seal means disposed in said housing inlet and outlet openings in engagement with said peripheral sealing surfaces for sealing between said valve housing and said plug valve in both of the alternate positions of said plug valve, said seal means being guided in said inlet and outlet openings for axial movement toward and away from said plug valve, each said seal means being a short tube having a radial outer cylindrical peripheral surface supported and slidably received in a respective transverse valve housing bore and having an axially inner sealing edge formed in a cylindrical curve matching said peripheral sealing surface of said plug valve, and annular wave spring means in engagement with the axially outer edge of said seal means, biasing said seal means toward said plug valve for sealing engagement therewith.

2 more elements

Duplex filter apparatus, comprising

a pair of filter housing, disposed on opposite sides of a central valve housing and interconnected in fluid communication therewith, a replaceable filter element in each of said filter housings,
cylindrical plug valve means in said central housing for directing fluid flow alternately to one of said filter housings and said respective filter element and for isolating the other of said filter housings for replacement of said filter element therein, said central housing having short transverse bores between said plug valve means and said filter housings,
tubular seal means disposed in said central housing transverse bores for sealing said plug valve means, each said tubular seal means being a short tube slidably received in said respective central housing transverse bore and having a cylindrically curved axial inner sealing edge in engagement with said plug valve means,
spring means biasing said tubular seal means toward said plug valve means,
each said filter housing having a cap at the upper end thereof for removal of said filter element in said housing,
a handle affixed to said valve means for rotating said valve means to one or another position to establish fluid communication with one or the other of said filter housings, said handle being exterior of said valve housing and disposed to overlie one or the other of said filter housing caps to prevent removal of said respective cap when said valve means is in a position to establish fluid communication with said filter housing on which said cap is disposed, and
spring biased lockout means interengageable with said handle for preventing movement of said handle when one or the other of said filter housing caps is in an open position.

4 more elements

Dependencies are inferred from the claim text.