Patent ID: 12208349

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is a return line filter for an industrial fluid reservoir, most commonly a hydraulic fluid reservoir or tank, and provides an in-tank filter assembly410with disposable filter element.

This application builds upon the work set forth in U.S. Patent Application publication 2020-0261833, now U.S. Pat. No. 11,358,080, titled “Return Line In-Tank Filter Assembly with Disposable Filter Element.” The discussion of the in-tank filter assemblies10,110,210, and310described in U.S. Patent Application publication 2020-0261833, now U.S. Pat. No. 11,358,080, will help describe the operation and function of the in-tank filter assembly410with disposable filter element of the present claimed invention

A first embodiment of the in-tank filter assembly10with disposable filter element set forth in U.S. Patent Application publication 2020-0261833 is shown inFIGS.1A-D. The in-tank filter assembly10includes a filter assembly mount14with tank coupling elements16to secure the assembly mount14to the tank12.

The tank12is actually shown as an insert, or weld ring, that itself is coupled to the tank or reservoir proper. This separate construction of the insert for the tank allows the insert to be formed with elements cooperating with the tank coupling elements16. However, for this application the terms “tank” or “reservoir” or “insert” can be used interchangeably. The tank coupling elements16may be any conventional securing elements, such as locking lugs shown or threads or the like. The lugs of elements16are received in grooves in the insert or tank12and twisted to lock the mount14in position.

The mount14further includes a sealing flange18configured to allow for sealing against cooperating surfaces of the tank12(or insert). As shown the flange18can receive a sealing O-ring or seal that radially seals against the tank. The receipt of the mount14including the tank coupling elements cooperating with elements16and the surface cooperating with flange18are essentially the only tank features needed on the tank12to accommodate the filter assembly10of the present invention and this greatly simplifies the tank design and construction. The use of an insert, or weld ring, on the tank further simplifies the application of the present invention to a wide variety of tanks.

The mount14includes a hex shaped portion20to facilitate the coupling and uncoupling of the filter assembly10with the tank12. The mount14includes an inlet tube20extending above the hex shaped portion. An inlet connection24is coupled to the inlet tube20through spiral spring connectors26that are received in a groove. The inlet connection24is coupled to an inlet line of the reservoir in a conventional fashion. Forming the inlet connection as separate from the remaining portions of the mount14allows the filter assembly to accommodate different sized inlet hoses/lines. In other words the same filter assembly10can be used with different sized inlet hoses by merely replacing the inlet connection24with the appropriate sized inlet. Further the inlet connection can be replaced with distinct hose couplings, like barb connections, if desired.

The filter assembly10includes a bypass structure30in the mount14which positioning yields an elevated flow path that avoids having contaminants within the interior space of the filter element from flowing into the interior of the tank during bypass operation.

The filter assembly10includes a filter element mount32extending from the bypass structure30for coupling a disposable filter element to the filter assembly. The filter element mount32is threaded and cooperates with threads on a disposable filter element coupling34to remove-ably secure the filter element to the filter assembly10.

The filter coupling34is attached to the top end cap40of the disposable filter element, with filter media42and external support wrap44extending between the top or upper end cap40and a lower or bottom end cap46. The terms top and upper are used interchangeably in this application as are the terms bottom and lower. The construction of the filter media42and the support wrap44is generally known in the art. For example the media42can be formed of a number of desired filter media and generally is a multi-layer structure.

The lower end cap46supports an inner fluid diverter48to modulate flow within the element, and a perforated outlet wrap50spaced from the outer support wrap44and media42also extending between the top end cap40and a lower end cap46.

The filter assembly10includes an inlet closing valve54that can seat against a sealing surface56to close off the inlet. The disposable filter element includes a valve opening stem52attached to the coupling34and engaging with the valve54when the filter element is coupled to the filter assembly. The inlet closing valve is helpful to prevent fluid spillage from residual fluid in the inlet line during disposable filter element change-out or replacement. Namely, the valve54will seal against surface56closing off the inlet when the filter element is removed, via operational or spring pressure (not shown).

The valve54has a built in failure mode that it breaks off at a reasonable operational pressure to prevent the system from causing other upstream problems should the filter element not be replaced and the mount returned into engagement without a filter element (and thus without opening the valve54). In the failure mode the valve54will have a component break and fold down to open the fluid pathway while still maintaining the valve components with the mount14so that pieces of the broken valve do not flow into the tank and downstream.

The inlet closing valve54could also be formed to be spring biased into the closed position with operational pressure in the inlet (higher than head pressure of residual fluid) sufficient to open the valve. This alternative allows the stem to be optional. The present design is somewhat easier to configure.

The filter element is an inside-out flow design in operation as shown. In operation the filter assembly10acts as a bowl-less or housing less in tank return line filter. The filter element is disposable, with the filter element comprising the combination of filter coupling34, top end cap40, filter media42, external support wrap44, lower end cap46, inner fluid diverter48, perforated outlet wrap50and valve opening stem52.

During replacement the filter element mount14is removed from the tank12. The filter element is unthreaded from the mount14. With the removal of the old filter element the inlet closing valve54closes preventing dripping of fluid from the inlet line during the change out. A new disposable filter element (also formed by filter coupling34, top end cap40, filter media42, external support wrap44, lower end cap46, inner fluid diverter48, perforated outlet wrap50and valve opening stem52) is threaded onto the mount14and the mount14is reattached to the tank12. The mount14and associated structure is maintained and no inlet reattachment is required with the filter assembly10. The mount14may be formed of metal or other sufficient material and the cost of forming this is less critical because it is not being replaced.

A second embodiment set forth in U.S. Patent Application publication 2020-0261833 is the in-tank filter assembly110with disposable filter element shown inFIGS.2A-C. The in-tank filter assembly110includes a filter assembly mount114with tank coupling elements116to secure the assembly mount114to the tank12. The mount114as shown provides for a threaded connection with elements116to the reservoir or tank12and includes a sealing flange118configured to allow for sealing against cooperating surfaces of the tank12(or insert). As shown, the flange118can receive a sealing O-ring or seal that seals against the tank. The receipt of the mount114including the tank coupling elements cooperating with elements116and the surface cooperating with flange118are essentially the only tank features needed on the tank12to accommodate the filter assembly110of the present invention and this greatly simplifies the tank design and construction.

The mount114includes a hex shaped portion120to facilitate the coupling and uncoupling of the filter assembly110with the tank. The mount114includes an inlet tube120extending above the hex shaped portion120. An inlet connection124extends from the inlet tube122and in this embodiment is integrally formed therewith. The inlet connection124is coupled to an inlet line in a conventional fashion. The inlet connection124uses a quick hose connection such as a hose barb, or alternatively a quick disconnect plug, to allow for easy connection and disconnection with the return line. The filter assembly110forms the inlet connection for the reservoir.

The filter assembly110includes a bypass structure130in the mount114. As with assembly10, the positioning of bypass structure130yields an elevated flow path that avoids having contaminants within the interior space of the filter element from flowing into the interior of the tank during bypass operation. The filter assembly110includes a filter element mount132extending from the bypass structure130for coupling the filter element to the disposable filter assembly110. The filter element mount132is attached to the top end cap140, with filter media142and external support wrap144extending between the top end cap140and a lower end cap146. The lower end cap46supports an inner fluid diverter148to modulate flow within the element, and a perforated outlet wrap150spaced from the outer support wrap144also extending between the top end cap140and a lower end cap146. The construction of the filter media142, the outer support wrap144and perforated outer wrap150is generally known in the art.

The filter element of assembly110is an inside out flow design in operation as shown. In operation the filter assembly110acts as a bowl-less or housing less in tank return line filter. The filter assembly110, including the integral filter element, is disposable. For replacement, the filter mount114is removed from the tank12and the inlet hose removed from the inlet connection124. The inlet hose is coupled to the inlet connection124of the replacement assembly110and the mount114thereof attached to the tank12. The entire assembly110, including the mount114, is disposable and thus molding the mount114may be desirable for cost considerations.

A third embodiment of the in-tank filter assembly210with disposable filter element as set forth in U.S. Patent Application publication 2020-0261833 is shown inFIGS.3A-C. The in-tank filter assembly210includes a filter assembly mount214(which may be molded) with tank coupling elements216to secure the assembly mount214to the tank12. The mount214as shown provides for a threaded connection with elements216to the reservoir or tank12as discussed above. The mount214further includes a sealing flange218configured to allow for sealing against cooperating surfaces of the tank12(or insert). The mount214includes a hex shaped portion220to facilitate the coupling and uncoupling of the filter assembly210with the tank12. The mount214includes an inlet tube220extending above the hex shaped portion220. An inlet connection224extends from the inlet tube222and in this embodiment, like the second embodiment, is integrally formed therewith. The inlet connection224uses a quick hose connection such as a hose barb, or alternatively a quick disconnect plug, to allow for easy connection and disconnection with the return line. The filter assembly210includes a bypass structure230in a bottom end cap246, which is a different position than the bypass30and130of assemblies10and110above.

With the lower bypass230location, the filter assembly210includes the top end cap240as integral with the mount214. The top end cap240may effectively be considered the lower surface of the mount214. Filter media242and external support wrap244extend between the top end cap240and a lower end cap246. The lower end cap246supports the bypass230as discussed above, and an outer shroud250spaced from the outer support wrap244and the media242and is also extending between the top end cap240and a lower end cap246. The construction of the filter media242and the outer support wrap244is known in the art.

The outer shroud250includes lower outlets252and differs from the perforated outer wraps150or50above. The outer shroud250extends from the endcap240and directs returning fluid that flows through the filter element to a position typically below fluid tank level in the tank before the fluid leaves the shroud250via outlets252. The filter element of assembly210, like assembly110and10, is an inside out flow design in operation as shown. In operation the filter assembly210acts as a bowl-less or housing less in tank return line filter. The filter assembly210, including the integral filter element, is disposable, like assembly110. For replacement, the filter mount214is removed from the tank12and the inlet hose removed from the inlet connection224. The inlet hose is coupled to the inlet connection224of the replacement assembly210and the mount214thereof attached to the tank12. The entire assembly210, including the mount214, is disposable and thus molding the mount214may be desirable for cost considerations.

A fourth embodiment of the in-tank filter assembly310with disposable filter element set forth in U.S. Patent Application publication 2020-0261833 is shown inFIGS.4A-B. Assembly310includes elements similar to assembly210above including a filter assembly mount314(which may be molded), threaded tank coupling elements316, a sealing flange318, a hex shaped portion320, an inlet tube320, an inlet connection324, a bypass structure330a top end cap340(integral with the mount314), filter media342and a lower end cap346. The lower end cap346supports the bypass330. The outer shroud350is spaced from the media342and extends from the top end cap240but not from the lower end cap346. The outer shroud350differs from shroud250as it does not include lower outlets252, and is not supported by the lower endcap346. The outer shroud350extends from the endcap340, namely from the coupling threads316, and directs returning fluid that flows through the filter element to a position typically below fluid tank level in the tank before the fluid leaves the shroud350via the space between the lower end cap346and the shroud350. The filter element of assembly310, like assemblies210,110and10, is an inside out flow design in operation as shown. In operation the filter assembly310acts as a bowl-less or housing less in tank return line filter. The filter assembly310, including the integral filter element, is disposable, like assemblies210and110. For replacement, the filter mount314is removed from the tank12and the inlet hose removed from the inlet connection324. The inlet hose is coupled to the inlet connection324of the replacement assembly310and the mount314thereof attached to the tank12. The entire assembly310, including the mount314, is disposable and thus molding the mount314may be desirable for cost considerations.

This application builds upon the work set forth in U.S. Patent Application publication 2020-0261833, and the in-tank filter assembly410with disposable filter element according to the present invention of the present application is shown inFIGS.5A-Cto9A-D.

The in-tank filter assembly410includes a two piece filter assembly mount comprising an upper filter mount414and a lower tank extension member415. The combined upper filter mount414and the lower tank extension member415combine in function to form the filter mount of earlier embodiments. The lower tank extension member415is coupled to the tank or reservoir proper, but in alternative construction may be considered or formed as part of the tank12. For example where a weld ring is used the weld ring could take the shape of the weld ring and the lower tank extension member415as shown, which is welded to the tank. This separate construction of the lower tank extension member415as shown, allows the lower tank extension member415to be formed with elements such as threads cooperating with the tank coupling elements416on the upper filter mount414. The tank coupling elements416may be any conventional securing elements, such as locking lugs shown or threads or the like with the upper filter mount414twisted to lock the upper filter mount414in position.

The lower tank extension member415further includes a sealing member418configured to allow for sealing against cooperating surfaces of the tank12(or insert). As shown the sealing member418may radially seals against the tank12. The receipt of the lower tank extension member415and the surface cooperating with sealing member418are essentially the only tank features needed on the tank12to accommodate the filter assembly410of the present invention and this greatly simplifies the tank design and construction. The use of an insert, or weld ring, on the tank further simplifies the application of the present invention to a wide variety of tanks and allows for retrofitting the design thereto.

The upper filter mount414includes a hex shaped portion with radial ribs420to facilitate the coupling and uncoupling of the filter assembly410with the tank12as described below.

An inlet connection cap424is coupled to the upper filter mount414through a retaining ring426that are received in a groove. A hose connection412is coupled to the inlet connection cap424through a retaining ring that allows for rotation. The hose connection412is coupled to an inlet line of the reservoir in a conventional fashion. Forming the hose connection412as separate from the remaining portions of the upper mount414allows the filter assembly to accommodate different sized inlet hoses/lines. In other words the same filter assembly410can be used with different sized inlet hoses by merely replacing the hose connection412with the appropriate sized inlet. Further the hose connection412can be replaced with distinct hose couplings, like barb connections, if desired.

The inlet connection cap424includes an inner member425extending inside and adjacent the lower tank extension member415and holds and positions an O-ring seal427against the extension member415for sealing.

The filter assembly410includes an element and bypass plate429which includes a bypass structure430in the plate429. The general formation and structure of the bypass structure430is known, namely a spring biased member remains closed in conventional operation but as upstream pressure builds (due to clogging of the filter media) the spring is overcome and the bypass structure430opens allowing flow to flow around the filter element into the tank12in bypass operation. In bypass operation the flow is directed through the perforated wrap into the tank12interior.

The plate429rests on a ledge formed in the lower tank extension member415and further includes a peripheral radial sealing member431sealing against the inside of the lower tank extension member415. It is contemplated that the periphery of the sealing member431may have a specialized shape to assure replacement with proper components if needed. The plate429can include handles433for ease of replacement of the filter element.

The filter assembly410includes a filter element mount432extending from the plate429for coupling a disposable filter element to the filter assembly410. The filter element mount432cooperates with filter element coupling434on the top or upper end cap440to form a lock and key connection to remove-ably secure the filter element to the filter assembly410. This is shown in detail inFIGS.9A-D. A simple twist lock is all that is needed to couple the element to the plate429.

The filter coupling434is attached to the top end cap440of the disposable filter element, with filter media442and external support wrap extending between the top or upper end cap440and a lower or bottom end cap446. The terms top and upper are used interchangeably in this application as are the terms bottom and lower. The construction of the filter media442and the wrap is generally known in the art. For example the media442can be formed of a number of desired filter media and generally is a multi-layer structure.

The lower end cap446supports an inner fluid diverter448to modulate flow within the element, and a perforated outlet wrap444spaced from the outer support wrap and media42also extending between the top end cap440and a lower end cap446. The diverter448reduces turbulence and improves de-aeration within the tank12.

The filter assembly410includes a spring biased inlet closing valve454on the inlet connection cap424that can seat against a sealing surface on the inlet connection cap424to close off the inlet. In this embodiment the valve454is spring biased to the closed position and will open under conventional operating pressures. The inlet closing valve454is helpful to prevent fluid spillage from residual fluid in the inlet line during disposable filter element change-out or replacement. Namely, the valve454will seal to facilitate changing of the element by closing off the inlet when the filter element is to be removed, with the operational positions shown inFIGS.7A-B. This avoid the dripping or flow of the fluid left in the inlet during maintenance. The inlet closing valve454is spring biased into the closed position with operational pressure in the inlet, namely any pressure that is higher than head pressure of residual fluid, sufficient to open the valve.

The filter element is an inside-out flow design in operation as shown. In operation the filter assembly410acts as a bowl-less or housing less in tank return line filter. The filter element is disposable, with the filter element comprising the combination of filter coupling434, top end cap440, filter media442, external support wrap, lower end cap446, inner fluid diverter448, and perforated outlet wrap444.

During replacement, the system is shut down and the loss of operation pressure closes the valve454. The upper mount414is removed from lower tank extension member415on the tank12through gripping the ribs420and rotating the upper mount414. In this configuration the plate429and the associated filter element remains in the tank after removal of the upper mount414. Now, with the interior elements of the assembly410exposed as shown inFIG.8B, the plate429and filter element can be removed from the tank via lift handles433as represented inFIG.8C. The filter element decoupled from the plate429by disconnecting the lock and key elements formed by432and434. During the removal of the old filter element the inlet closing valve454prevents dripping of fluid from the inlet line during the change out. A new disposable filter element (also formed by filter coupling434, top end cap440, filter media442, external support wrap, lower end cap446, inner fluid diverter448, perforated outlet wrap444and valve opening stem52) is coupled to the plate429and the plate429is reattached to lower tank extension415in the tank12. The upper mount414and associated structure is maintained and no inlet reattachment is required with the filter assembly410. The upper mount414may be formed of metal or other sufficient material and the cost of forming this is less critical because it is not being replaced.

All of the above embodiments may further include operational performance enhancing features such as magnetic inserts located in the inlet of the filter which operate to strain out magnetic particles increasing filter life. For the shroud implementing embodiments the filter may further include mesh covered openings or the outlet space which evens out fluid flow, lowers fluid velocity and coalesces free air, all combining to de-aerate the fluid.

It will be apparent to those of ordinary skill in the art that various changes may be made to the present invention without departing from the spirit and scope thereof. The spirit and scope of the present invention is defined in the appended claims and equivalents thereto.