FLUID FILTER

Abstract: A preferred fluid filter assembly (10) includes a container having a first end member (26), a second end member (20) opposite the first end member, at least one centrally disposed first passageway (28), at least one second passageway (34) generally parallel to the first passageway and a plurality of radially extending channel ribs (40) connected to at least the second end member between the first and second passageways. In another embodiment, the fluid filter assembly includes a conical flange supporting a tubular member that defines at least a portion of a first passageway. A method of channeling fluid flow in a fluid filter assembly employs the radially extending channel ribs to direct fluid flow between the first and second passageways.

Description: FLUID FILTER CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part application of U.S. Application serial no. 08/714,021 filed September 11, 1996, which is a continuation-in-part application of U.S. Application serial no. 08/652,229 filed May 23, 1996, both of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION The present invention relates to a method and a structure for channeling fluid flow in a fluid filter. More particularly, the present invention relates to a method and a structure for directing fluid flow in an essentially cylindrical container having one end that defines both the inlet and outlet for fluid flow. This invention is especially useful for fluid filtration applications such as filtering lubricating oil used in internal combustion engines. A fluid filter assembly such as a full-flow filter is generally enclosed in a cylindrical vessel having a first end and an opposite second end. Unfiltered fluid is received under pressure from the fluid flow circuit. The flow of fluid is then directed through at least one filter medium that traps foreign particles. The fluid is thereafter directed to the outlet and returned to the fluid flow circuit in a considerably cleaner state. A cap seals the first end of the vessel and contains at least one inlet aperture for the entrance of unfiltered fluid and at least one outlet aperture for the exit of filtered fluid such that the flow path of the unfiltered fluid is parallel to the flow path of the filtered fluid. Conventionally, fluid flow is directed from the inlet to the outlet by the pressure differential between the inlet and the outlet, as well as the vessel walls. However, some of the fluid may collect in cavity areas created by the design and shape of the filter assembly. Thus, without another means of directing flow, a portion of fluid flow may not be forced through the filter in an appropriate manner. In addition, when a liquid such as lubricating oil, hydraulic oil, transmission oil, or fuel oil is introduced into a vessel, burst pressure is formed in the vessel as a result of the pressure of the liquid forced into the vessel by a pump, as well as back pressure from, for example, clogged media and/or inadequate relief by safety relief valve. The force caused by this pressure may deform the vessel and thereby adversely affect the physical integrity of the filter vessel. SUMMARY OF THE INVENTION In a first aspect, the present mvention is directed to a fluid filter assembly housed in a container having a central axis, a first container end connected to a first end member, a second container end opposite the first container end and connected to a second end member. The assembly includes at least one first passageway centrally disposed about the central axis; at least one second passageway generally parallel to the first passageway; and a plurality of channel ribs between the first passageway and the second passageway. The channel ribs are connected to at least the second end member and extend radially with respect to the central axis. In a preferred embodiment, at least a portion of the first passageway is defined by a tubular member that is integral with the first end member. In another preferred embodiment, the first end member includes a conical flange supporting the tubular member. The first end member preferably includes a plurality of flange ribs connecting the tubular member and flange. The second passageway preferably contains at least one filtration element so that it is connected to inlet openings of the filter assembly. In addition, the channel ribs preferably have essentially uniform width, length and height. The present invention also relates to a method for channeling fluid flow in the previously described ribbed fluid filter assembly. The method includes the steps of introducing a fluid into the first passageway, directing the fluid through the filtration element, directing a substantial portion of the fluid that passes through the filtration element from the first passageway to the first channel rib end, directing the portion of the fluid from the first channel rib end of the channel ribs to the second channel rib end and directing the portion of the fluid from the second channel rib end to the second passageway. In one embodiment, the first passageway is centrally disposed about the central axis and the second channel rib end is adjacent to the sidewall of the container. In another aspect, the present invention is a fluid filter assembly having a housing, the housing having a central axis and including a first container end and an opposite second container end, the assembly comprising at least one filtration element; at least one first passageway centrally disposed about the central axis of the housing, at least a portion of the first passageway being defined by a tubular member; at least one second passageway circumferentially disposed about the first passageway; and the first container end comprising a conical flange supporting the tubular member. In yet another aspect, the present invention is a fluid filter assembly having a housing, the housing having a central axis and including a first container end and an opposite second container end, the assembly comprising at least one filtration element; at least one first passageway centrally disposed about the central axis of the housing, at least a portion of the first passageway being defined by a tubular member; at least one second passageway circumferentially disposed about the first passageway; the first container end comprising a conical flange supporting the tubular member; and a plurality of channel ribs between the first passageway and the second passageway, the channel ribs extending radially within the container and being connected to at least the second end member. The filter assembly and method of the preferred embodiments of the present invention improve fluid flow in a container having parallel inlet and outlet passageways by channeling the fluid from the inlet passageway towards the outlet passageway. The channel rib structure in the fluid filter ensures that all of the fluid actually circulates through the assembly. In addition, the channel ribbed structure and flange ribs enhance structural integrity of the housing. Furthermore, the channel ribs provide a spacing means between the filtration element and the second end and thus provide a connecting path between the first and second passageways. Moreover, the conical flange enhances distribution of fluid introduced to the filter assembly. These and other advantages and features of the present invention will be better understood upon review of the following detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of an oil filter equipped with the unique features of a first embodiment the present invention. FIG. 2 is a first end plan view taken along the line 2-2 of FIG. 1. FIG. 3 is a second end plan view taken along the line 3-3 of FIG. 1. FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 1. FIG. 5 is an enlarged view of the designated portion A of FIG. 1. FIG. 6 is an end plan view of an oil filter equipped with the unique features of a second embodiment of the present invention. FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 6. FIG. 8 is a cross-sectional view of a third embodiment of an oil filter of the present invention. FIG. 9 is an exploded perspective view of the oil filter of FIG. 8. DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS For illustration purposes, a first embodiment of the present invention is shown in an oil filter assembly 10. Other details of the oil filter assembly 10 are shown in two other applications, filed earlier, titled "Filtration Element And Method of Making The Same," Serial No. 08/712,122, and "Safety Relief Valve Useful In An Oil Filter," Serial No. 08/712,130; and parent applications of these applications, namely serial nos. 08/652,771 and 08/652,226, all of which are hereby incorporated by reference. The oil filter assembly 10 is contained in a cylindrical housing or container 12 with a central axis 14. The housing 12 has a first container end 16 and an opposite second container end 18. The housing is made up of a first end member 26 adjoined to the first container end 16, a sidewall 24 and a second container end member or base 20 adjoined to the second container end 18. The first end member 26 has an interior surface 23 and an opposite exterior surface 25. As shown in FIG. 2, the exterior surface 25 defines a slot 27 that is configured to accommodate a seal or gasket (not shown). As shown in FIG. 1 , the oil filter assembly 10 contains a first passageway 28 centrally disposed about the central axis 14. Essentially the entire portion of the first passageway 28 is defined by a central tubing. The central tubing 28 has a central axis that is coincident with that of the housing 12. In the illustrated embodiment, the first passageway is the outlet for fluid flow out of the housing 12. The illustrated central tubing is thus an outlet tube. The illustrated outlet tube includes a tubing exterior end or central outlet 29 defined by the first end member 26, a tubing interior end or normal outlet port 31, which is adjacent to the second container end 18 and at least one bypass outlet port 30 between central outlet 29, and normal outlet port 31. The outlet tube has an outer tubing wall 32 and an inner tubing wall 33. The housing and other internal components are preferably made of recyclable plastic materials. The assembly 10 further contains a plurality of second passageways 34 that are generally parallel to the first passageway 28 and are circumferentially spaced relative to the first passageway 28. In the illustrated embodiment, the second passageways are the inlet for fluid flow into the housing 12. An anti- drain back valve 37 is disposed adjacent to inlet ports 36 and held in place by a retainer ring 38. The second passageways begin at inlet ports 36, which are defined by the first end member 26. The filter assembly 10 of FIG. 1 also contains a coarse filtration element 70 and a fine filtration element 100 placed in series relative to each other and concentrically disposed about the outlet tube 28. The fine filtration element 100 is supported by element support 102. A permanently open fine filter bypass path 104 is disposed parallel to the fine filter element 100. The assembly 10 also contains a pressure relief valve assembly 110 adjacent the bypass outlet port 30 and configured to be disposed in the second passageway between the inlet ports 36 and the coarse filtration element 70. Under normal operating conditions, oil enters the filter assembly 10 through the eight inlet ports 36. From there the oil travels through coarse filtration element 70, and partially through fine filtration element 100. Oil is directed by a plurality of channel ribs 40 adjacent to the closed container end 18 of the cylindrical housing 12 towards the normal outlet port or tubing interior end 31 and thereafter exits the filter assembly 10 from the central outlet or tubing exterior end 29. Under bypass operating conditions, the relief valve system 110 is configured into an open position such that oil from the inlet ports 36 flows through cap opening 134 to the bypass outlet port 30, into outlet tube 28 and immediately returns to the engine. As shown in FIG. 1, a plurality of channel ribs 40 are connected to at least the second end member 20. Each of the channel ribs has two faces 41, a first side 42 adjacent to the tubing interior end 31 and an opposite second side 44 adjacent to the interior face 22 of the base 20. In the illustrated embodiment, the base 20 is cup-shaped. Each of the channel ribs also has a first channel rib end 46 adjacent to the tubing interior end 31 and a second channel rib end 48 adjacent to the base wall 21. FIG. 2 shows six channel ribs 40 extending radially from the center 23 of the base 20, which lies in the central axis 14. As shown in FIG. 2, each pair of channel ribs are disposed at an angular disposition 50 ("channel rib angle") relative to each other. Each channel rib 40 also has physical characteristics including height 52 and length 56. As shown in Figs. 4 and 5, each channel rib 40 is further defined by a first width 54 of the first side 42 and a second width 55 on the second side 44 of the channel rib. Moreover, each channel rib 40 is defined by the angular disposition 60 relative to the interior face 22 ("base angle"), as shown in FIG. 5. FIG. 5 also shows that the first side 42 of each channel rib is disposed at a distance 58 from the tubing interior end 22. In accordance to the method of the present invention, oil under pressure is introduced into the second passageway 34 through the inlet openings 36. Under normal operation, all of the oil is directed through coarse filtration element 70. Then a portion of the oil is directed through fine filtration element 100 and the remaining portion is directed to the fine filter bypass path 104. A substantial portion of the oil is directed to the second channel rib end 48. The channel ribs 40 then channel the portion of the oil from the second channel rib end 48 towards the first channel rib end 46 and thereafter direct the fluid from the first channel rib end 46 into the tubing interior end 31 of the tubular member 28. The channel ribs 40 thus provide a space between the fine filter 100 and the second end member 20 and thereby a connecting flow path between the first and second passageways 28, 34. The configuration and radial disposition of the channel ribs thus channels fluid from the second passageway 34 to the first passageway 28. In the filter assembly 10 of FIG. 1 , the channel ribs 40 channel the oil flow from the second passageway 34 to the first passageway 28. In another embodiment of the invention (not shown), where the inlet opening of the cylindrical container is centrally disposed about the central axis of the housing, the channel ribs would channel fluid flow from a centrally disposed inlet passageway so that it is evenly distributed over one or more filtration elements, from where it flows parallel to the inlet passageway to outlet openings that are radially disposed about the inlet opening. While FIG. 1 shows one first passageway 28 defined by a tubular member having a central axis that is coincident to that of the housing 12, it is understood that this passageway can also be defined by other configurations, such as, for example, a plurality of concentric tubes or a plurality of tubes radially disposed about the container's central axis. Thus, the term "centrally disposed" includes all of the possible configurations wherein the first passageway is closer to the central axis 14 than the second passageway. It is also understood that the second passageway 34 can be defined by configurations other than the illustrated inlet openings 36, such as, for example, one or more openings that are concentrically spaced relative to a first passageway. In addition, it is understood that the term "cylindrical" is used to describe an essentially cylindrical configuration, and includes polygonal configurations containing five or more sides. It is further understood that the polygonal configurations may contain rounded corners at points where two sides meet. The number of channel ribs that are provided in the filter assembly depends upon the desired channel rib angle 50 between each pair of channel ribs as well as the physical characteristics 52, 54, 56 of the channel ribs 40. The channel rib angle 50 shown in the figures is essentially the same between all of the channel ribs 40. In a preferred embodiment, the channel rib angle is between about 5° to about 75°, more preferably from about 55° to about 65°. In another embodiment of the present invention, the angle between at least one pair of channel ribs may be different from the angle between another pair of channel ribs. The illustrated channel ribs 40 have essentially uniform height 52. In the illustrated embodiment, each of the channel ribs has a height that is substantially equal to that of the base 20, although this parameter is not crucial to the invention. In another embodiment of the invention (not shown), at least one channel rib may have a different height from another channel rib. In yet another embodiment of the invention (not shown), one or more channel ribs are provided with a height at the first channel rib end 46 that is different from that at the second channel rib end 48. For example, the height at the first channel rib end 46 may be less than that at the second channel rib end 48 or vice versa. It should be understood that where there is a tubular member defining essentially the entire first passageway 28, such as that illustrated in the figures, at least the first channel rib end 46 is spaced from the tubing interior end 31 to provide a distance 58 therebetween. Preferably, the distance 58 is between about 1/64 inch to about 1/16 inch, more preferably from about 1/40 inch to about 1/30 inch. In another embodiment, shown in FIGS. 8 and 9 discussed below, only a portion of the first passageway is defined by a central tubular member that is integral with the first end member. For example, the filter assembly may contain a vertically pleated cellulose filtration media wound around a media support such as a filtration media center tube, a first portion of which is placed around a portion of the integral central tubular member, and a remaining portion is disposed adjacent to the ribs and in series with the central tubular member to define essentially the remaining first passageway. The length of the integral central tubular member in this case can be about 1/3 of the length of the illustrated tubular member 28. The illustrated channel ribs 40 have essentially uniform first widths 54 (shown in FIG. 4) as well as essentially uniform second widths 55 (shown in FIG. 5). In another embodiment, at least one channel rib 40 may have a different first width 54 or second width 55 or both as compared to that of the other channel ribs. The channel ribs 40 may have a tapered configuration, where the first width 54 is narrower than the second width 55, or vice versa. In a preferred embodiment, each of the channel ribs 40 have a second width 55 of from about 0.05 inch to about 0.125 inch with a taper on each face 41 of the channel rib measuring from about 1.5° to about 3.5° such that the first side is narrower than the second side. The illustrated channel ribs 40 have an essentially uniform length 56. While this is one of the preferred embodiments, the length 56 of one channel rib may also vary from that of another channel rib. For example, the channel ribs adjacent to each other may alternate in length. Preferably, the channel ribs are provided with a length 56 such that at least some of the channel ribs extend to form a circle having a radius essentially equal to the radius of the inner tubing wall 33. FIG. 4 illustrates a preferred embodiment wherein all of the channel ribs extend to form a circle having a radius essentially equal to the radius of the inner tubing wall 33 at the tubing interior end 31. Each of the illustrated channel ribs 40 have a base angle 60 such that the channel rib is essentially perpendicular to the interior face 22 of the base. While this is a preferred angular disposition for the illustrated embodiment, the angular disposition 60 may vary from about 5° to about 175°. The preferred base angle may vary depending upon the relative disposition of the inlet and outlet passageways. Thus, in an embodiment where the inlet is centrally disposed about the container's central axis relative to the outlet, the preferred base angle may not necessarily be about 90°. The channel ribs 40 are adjoined or connected to at least the base 20. In the illustrated embodiment where the base 20 is cup-shaped, the channel ribs 40 are preferably adjoined to the base wall 21 as well as the interior face 22 of the base. The channel ribs 40 may also be adjoined to the container sidewall 24. Where the base is in the form of a circular plate (not shown), the channel ribs are preferably adjoined to the sidewall of the container as well as the interior face of the base. Any means suitable for adjoining the channel ribs to the base may be used. Useful adjoining means include, for example, adhesion, injection molding, sonic welding and vibration welding. When the channel ribs 40 are formed with the base in an injection molding process, the channel ribs and base are formed as one monolithic unit. The preferred embodiment of the present invention channels fluid flow and thereby reduces the collection of fluid in the cylindrical container such as in cavity areas 65, 67. The preferred embodiment also reinforces the second end member 20 and thereby enhances the structural integrity of the housing 12. Each channel rib strengthens the corner portions 62 of the illustrated cup-like base, or, in an alternate embodiment (not shown), the joint portions connecting the container sidewall and a flat base. By reinforcing these corner portions and joint portions, the channel rib structures reduces structural deformation of the container that may be caused by stresses from burst pressure. It is understood that the structural integrity of the housing and the dynamics of fluid flow are also affected by the relative dimensions of other components of the filter assembly. For example, to channel fluid flow in oil filter assembly 10, the container sidewall 12, having a length 204, can be tapered so that the inner diameter 200 at the first container end 16 is greater than the inner diameter 202 at the second container end 18. In addition, the height 210 of the base 20, as well as the angular disposition 208 between the sides of a noncircular base and the distance 206 between the center and the sides of the noncircular base also may affect fluid flow. Moreover, the distance 214 between the center of the first end member, having a diameter 212, and the center of an inlet port 36, the radius 216 of the inlet port 36, as well as the inner diameter 218 and the outer diameter 220 of the central tube 28 affect the amount of fluid that flows through the assembly. FIGS. 6 and 7 illustrate a second preferred oil filter assembly 300. Other details of the oil filter assembly 300 are shown in two other applications, that were filed earlier, titled "Filtration Element And Method of Making The Same," Serial No. 08/712,122, and "Safety Relief Valve Useful In An Oil Filter, " Serial No. 08/712,130; and parent applications of these applications, namely serial nos. 08/652,771 and 08/652,226, all of which are hereby incorporated by reference. The filter assembly 300 comprises an interior chamber 310 enclosed by a filter housing 320. The filter housing 320 has a cylindrical side wall 322 that connects a first end member 324 to an opposite second end member 326. The second end member 326 includes a plurality of channel ribs 328. In the preferred embodiment shown, the thickness of the side wall 322 increases near the first end member 324 of the housing 320. As best seen in FIG. 7, the first end member 324 of the filter housing comprises rim 330 having an exterior surface 332 and an interior surface 334. The rim 330 of the first end member 324 is bonded to the edge of the filter housing side wall 322. In the embodiment illustrated, a tongue and groove joint 336 forms the connection between the rim interior surface 334 and the side wall 322. As best seen in FIG. 6, the rim exterior surface 332 comprises a continuous slot 338. The slot 338 is configured to accommodate a seal or gasket (not shown). The first end member is attached to the housing by a spin- weld process. The first end member 324 further comprises a centrally disposed first passageway 340. The first passageway 340 is defined by an outlet tube 342 having an exterior end 344 and an interior end 346. The outlet tube exterior end 344 is positioned approximately even with the plane of the rim exterior surface 332. The outlet tube terminates at the outlet tube interior end 342 near the channel ribs 328. The first end member 324 further comprises a flange member 350 which projects outwardly from the outlet tube 342 and terminates at the rim 330. In the preferred embodiment shown, the flange member 350 has a conical shape. As best seen in FIG. 7, the juncture of the flange member 350 and the outlet tube 342 is angularly disposed and inward of the outlet tube exterior end 344. The conical shape of the flange member 350 and the configuration of the juncture to the outlet tube 342 increases the strength of the first end member 324 and reduces the possibility of structural deformation of the container that may be caused by stresses from burst pressure. A recessed inlet area 352 is formed exterior to the flange 350 between the outlet tube 342 and the rim 330. The primary function of the inlet area 352 is to collect and distribute inlet fluid. A plurality of flange ribs 354 connect the exterior surface of the flange member 350 to outlet tube 342. The exterior edges of the flange ribs 354 are disposed inward of the plane of the rim exterior surface 332 to allow fluid to flow throughout the inlet area 352. The flange ribs 354 provide additional support and rigidity for the connection of the flange member 350 to the outlet tube 342. In an alternative embodiment (not shown), the flange ribs 354 are connected between the interior surface of the flange member 350 and the outlet tube 342. The location of the flange ribs 354 on the inside of the filter housing 320 prevents the flange ribs 354 from interfering with the flow of fluid throughout the inlet area 352. The flange member 350 comprises a plurality of inlet ports 356 that are circumferentially spaced relative to the first passageway 340 and between the flange ribs 354. The inlet ports 356 provide a fluid communication between the inlet area 352 and the second passageway 358 of the filter assembly 300. An anti-drain back valve 360 is disposed adjacent to the inlet ports 356 and held in place by a retainer ring 362. In another embodiment (not shown), no anti-drain back valve is necessary. In another embodiment (not shown), the anti-drain back valve can be held in place by another component of the assembly, such as, for example, a portion of a filtration element. In the embodiment illustrated, the rim 330, flange member 350, flange ribs 354, and outlet tube 342 are manufactured as a monolithic component, preferably by injection molding. The filter assembly 300 also contains a coarse filtration element 500 and a fine filtration element 510 placed in series relative to each other and concentrically disposed about the outlet tube 342. The fine filtration element 510 is supported by element support 512. A permanently open fine filter bypass path 514 is disposed parallel to the fine filtration element 510. The assembly 300 also contains a pressure relief valve 610 adjacent to at least one bypass outlet port 348, which is defined by the outlet tube 342. The bypass outlet port 348 is configured to be disposed between the inlet ports 356 and the coarse filtration element 500. As illustrated in FIG. 7, the safety relief valve 610 is disposed inside the outlet tube 342. Under normal operating conditions, oil enters the filter assembly 300 from the eight inlet ports 356. From there the oil travels through coarse filtration element 500, and partially through fine filtration element 510. Oil is directed by a plurality of channel ribs, which are connected to the second end member 320. Under bypass operating conditions the relief valve 610 is configured into an open position such that oil from the inlet ports 356 flows through bypass outlet ports 348, into outlet tube 342 and immediately returns to the engine. Preferably, the combined area of the bypass outlet ports 348 allows the same or more volume of liquid to pass through the openings as is allowed in through the inlet ports 356 in the first end member 324. In another embodiment, the filter assembly contains a central outlet tube that does not include bypass outlet ports. FIGS. 8 and 9 illustrate a third preferred oil filter assembly 400. The filter assembly 400 comprises an interior chamber 410 enclosed by a filter housing 420. This embodiment uses the same housing as the embodiment illustrated in FIGS. 6 and 7, so that it could be made in the same mold. The filter housing 420 has a cylindrical side wall 422 that connects a first end member 424 to an opposite second end member 426. The first end member 424 has an interior surface 423 and an opposite exterior surface 425. As shown in FIG. 8, the exterior surface 425 defines a slot 438 that is configured to accommodate a seal or gasket 439 (shown in FIG. 9). The first member 424 also includes a flange member 450 similar to the flange member 350 shown in FIG. 7. The second end member 426 includes a plurality of ribs 428. As discussed below, the ribs 428 of the housing 420 do not have all of the same functions as the channel ribs 328 shown in FIG. 7. In the preferred embodiment shown, the thickness of the side wall 422 increases near the first end member 424 of the housing 420. As best seen in FIG. 9, the filtration element 700 includes a media 710 supported by a filtration media center tube 712 and two planar supports 714 and 716. Filtration media 710 can be a synthetic or nonsynthetic, woven or nonwoven media. The first planar support 714 is annular in shape to allow fluid communication between the outlet tube 442 and the media center tube 712. The illustrated second planar support 716 has the same annular shape as the first planar support 714, wherein annular center 718 is closed, in this case by epoxy. As best shown in FIG. 8, the second planar support 716 rests upon the ribs 428. Thus, the ribs 428 in this embodiment support the filtration element 700. The first end member 424 further comprises a centrally disposed first passageway 440. The first passageway 440 is partially defined by an outlet tube 442 having an exterior end 444 and an interior end 446. The outlet tube exterior end 444 is positioned approximately even with the plane of the rim exterior surface 432. The outlet tube terminates at the outlet tube interior end 442 near the filtration media center tube 712, which defines the remaining first passageway 440 and terminates near the ribs 428. The flange member 450 comprises a plurality of inlet ports 456 that are circumferentially spaced relative to the first passageway 440 and between the flange ribs 454, like those shown in Fig. 6. The inlet ports 456 provide a fluid communication between the inlet area 452 and the second passageway 458 of the filter assembly 400. An anti-drain back valve 460 is disposed adjacent to the inlet ports 456 and held in place by a retainer ring 462. In another embodiment (not shown), the anti-drain back valve can be held in place by another component of the assembly, such as, for example, a portion of a filtration element. A substantial portion of the second passageway 458 is defined by the outer circumference of the filter element 700 and the interior surface of the side wall 422. Under normal operating conditions, oil enters the filter assembly 400 from eight inlet ports 456. From there the oil from the second passageway 458 travels through filtration element 700. Oil is directed to the center tube 712 and flows through both the center tube 712 and the outlet tube 424 and returns to the engine. The channel and flange rib structures, first and second end members, sidewall and central tubular member can be made of any material that can withstand a minimum pressure of about 300 p.s.i. (for a light vehicle spin-on tube oil filter) and a temperature range of from about -40 °F to about 300 °F. For example, these components can be made of a metallic material that can be welded together, or a thermoplastic elastomeric material. Preferably, these components include thermoplastic elastomers. In general, a thermoplastic elastomer (TPE) is a rubbery material that can be processed in the molten state as a thermoplastic and that has many of the performance characteristics of thermoset rubber. TPE has elastic properties such as flexibility, ease of distortion under a predetermined applied load, and recovery of most of its original shape after removal of an externally applied stress. TPE types that are suitable for the present invention include, for example, polymer blends such as thermoplastic olefinic blends, which contains a ethylene-propylene terpolymer (EPDM) with polypropylene (PP) or polyethylene (PE), and blends of nitril rubber (NBR) and polyvinylchloride (PVC); two-phase materials known as elastomeric alloys that contain, for example, EPDM, NBR or natural rubber (NR) as the soft phase and a polyolefin such as PP as the hard phase; block copolymer TPE containing both hard and soft segments along a common polymer chain that include, for example, polymers of styrene and dienes (known as styrenics), copolyesters (COPs), polyurethanes and polyamides. Specific examples of suitable TPEs can be found in Harper, Handbook of Plastics, Elastomers, and Composites (McGraw-Hill 2nd Ed. 1992), the relevant portions of which are incorporated herein by reference. Preferably, the components are made of nylon materials with one or more additives. Suitable additives include, for example, mineral or glass fillers, fibers containing aramid, carbon, ceramics, glass or thermoplastics, as well as combinations thereof. For example, a Nylon 6/6 containing approximately 45% glass fiber can be used. Preferably, the housing including the rib structures, second end member and sidewall are concurrently formed in an injection molding process ("first unit"). Similarly, the first end member, and central tubular member including the associated flange and flange ribs are concurrently formed in an injection molding process ("second unit"). The following example illustrates the present invention in an oil filter assembly. EXAMPLE The housing of the oil filter assembly illustrated in Figures 1-5 was provided with the structure of the present invention. The assembly was housed in a cylindrical container with a cylindrical sidewall, a circular first end member sealing the first end a second end member or base having a dodecagonal configuration (with twelve sides). The first end member defined one central outlet port and eight inlet openings radially spaced from the outlet port. A central tube was molded with the first end member and connected to the central outlet port. The cylindrical sidewall is tapered so that the diameter at the container's first end is greater than the diameter at the container's second end. The relevant dimensions of these components are listed in Table I, along with corresponding component numbers and the respective figures that illustrate these dimensions. Table I. Dimensions of Housing Components Six channel ribs were pre-molded onto the base of the assembly housing by injection molding. Each channel rib was provided with dimensions that were the same with respect to the other channel ribs. These dimensions are listed in Table II, along with corresponding reference numbers and respective figures that illustrate these dimensions. Table II. Dimensions of Each Channel Rib It was found that the filter assembly equipped with this structure is qualified to withstand an operating pressure of up to about 400 p.s.i.. Therefore, an oil filter assembly containing the channel ribs is expected to retain its structural integrity at about 100 p.s.i., the maximum expected burst pressure in a light-vehicle oil filter environment. Filter assemblies of various sizes employing the same relative proportions of the various components had essentially the same performance. It should be noted that the fluid filter unit of the present invention can filter any type of fluid, including gas and liquid such as hydraulic oil, fuel oil for house heaters and transmission oil. In addition, the fluid filter unit of the present invention may be used to filter fluid by itself or in conjunction with an auxiliary filter unit. It should further be understood that the number of filtration elements may vary in a fluid filter unit of the present invention. Of course, it should be understood that a wide range of changes and modifications can be made to the embodiments described above. It is therefore intended that the foregoing description illustrates rather than limits this invention, and that it is the following claims, including all equivalents, which define this invention.

Claims: WHAT IS CLAIMED IS: 1. A fluid filter assembly housed in a container having a central axis, a first container end connected to a first end member, a second container end opposite the first container end and connected to a second end member, said assembly comprising: a) at least one first passageway centrally disposed about the central axis; b) at least one second passageway substantially parallel to the first passageway; and c) a plurality of channel ribs between the first passageway and the second passageway, said channel ribs extending radially within said container and being connected to at least the second end member. 2. The assembly of claim 1 wherein said second passageway includes at least one filtration element. 3. The assembly of claim 1 wherein said plurality of channel ribs each have essentially the same height. 4. The assembly of claim 1 wherein said channel ribs comprise: a) a first channel rib side adjacent to said second container end, said first side having a first width; and b) a second channel rib side opposite said first channel rib side, said second side having a second width that is wider than said first width. 5. The assembly of claim 1 wherein said plurality of channel ribs each have essentially the same length. 6. The assembly of claim 1 wherein said channel ribs are adjoined to the second container end. 7. The assembly of claim 6 wherein said channel ribs and the second end member are portions of a monolithic unit. 8. The assembly of claim 1 wherein said channel ribs are provided at an angular disposition relative to each other such that fluid flowing from the first passageway is channeled to the second passageway by said channel ribs. 9. The assembly of claim 1 wherein said channel ribs are provided at an angular disposition relative to each other such that fluid flowing from the second passageway is channeled to the first passageway by said channel ribs. 10. The assembly of claim 1 wherein the container has an essentially cylindrical shape. 11. An oil filter assembly having a housing, said housing having a central axis and including a first container end and an opposite second container end connected to a second end member, having an interior face, said assembly comprising: a) at least one filtration element; b) at least one first passageway centrally disposed about the central axis in said housing; c) at least one second passageway circumferentially disposed about said first passageway; and d) a plurality of channel ribs between said filtration element and said interior face, said channel ribs extending radially from the central axis. 12. The assembly of claim 11 wherein: a) at least a portion of said first passageway is defined by a tubular member; and b) said channel ribs have a first side and an opposite second side, said first side disposed adjacent to the filtration element, said second side disposed adjacent to said second container end. 13. The assembly of claim 12 wherein said first passageway is also defined by a media support that supports said filtration element. 14. The assembly of claim 12 wherein said tubular member has a tubing interior end adjacent to said channel ribs. 15. The assembly of claim 11 wherein said channel ribs have an angular disposition that is essentially perpendicular to said interior face. 16. The assembly of claim 11 wherein said housing has an essentially cylindrical shape. 17. A method for channeling fluid flow in a fluid filter assembly housed in a container having a central axis, the container including: i) a first container end connected to a first end member, ii) a second container end opposite the first end and connected to a second end member, iii) at least one container sidewall disposed between said first and second end members, iv) at least one first passageway, said first passageway containing at least one filtration element, v) at least one second passageway generally parallel to the first passageway, and vi) a plurality of channel ribs between the first and second passageways, said channel ribs being radially disposed with respect to the container central axis, each channel rib having a first channel rib end and an opposite second channel rib end, said channel ribs being connected to at least said second end member, the method comprising: a) introducing a fluid into said first passageway; b) directing the fluid through said filtration element; c) directing a substantial portion of the fluid that passes through said filtration element from said first passageway to the first channel rib end; d) directing the portion of the fluid from the first channel rib end of said channel ribs to the second channel rib end; and e) directing the portion of the fluid from the second channel rib end to the second passageway. 18. The method of claim 17 wherein said first passageway is centrally disposed about the central axis and the second channel rib end is adjacent to said sidewall. 19. The method of claim 17 wherein said second passageway is centrally disposed about the central axis and the first channel rib end is adjacent to said sidewall. 20. The method of claim 19 wherein at least a portion of said second passageway is defined by a tubular member. 21. The method of claim 20 wherein said first end member comprises a conical flange supporting said tubular member. 22. The method of claim 21 wherein said fluid is introduced into said first passageway through one or more inlet ports provided in said flange. 23. The method of claim 22 wherein step a) comprises: (a)(1) collecting said fluid in an inlet area formed by an exterior surface of said flange; (a)(2) distributing said collected fluid in said inlet area; and (a)(3) directing said distributed fluid to said inlet ports. 24. The method of claim 20 wherein said first end member further comprises a plurality of flange ribs. 25. The method of claim 17 wherein said channel ribs are angularly disposed relative to an interior surface of said second end member to further direct the portion of fluid from the second rib end to the second passageway. 26. The method of claim 17 wherein said container has an essentially cylindrical shape. 27. A fluid filter assembly having a housing, said housing having a central axis and including a first container end and an opposite second container end, said assembly comprising: a) at least one filtration element; b) at least one first passageway centrally disposed about the central axis of said housing, at least a portion of said first passageway being defined by a tubular member; c) at least one second passageway circumferentially disposed about said first passageway; and d) a first end member connected to said first container end, said first end member comprising a conical flange supporting said tubular member. 28. The assembly of claim 27 wherein said tubular member projects outwardly from said flange. 29. The assembly of claim 27 wherein a plurality of flange ribs are connected between said tubular member and said flange. 30. The assembly of claim 27 wherein said tubular member comprises a pressure relief valve assembly. 31. The assembly of claim 27 wherein said flange comprises one or more inlet ports, said inlet ports being in fluid communication with said second passageway. 32. The assembly of claim 27 wherein said housing is essential cylindrical in shape. 33. A fluid filter assembly having a housing, said housing having a central axis and including a first container end and an opposite second container end, said assembly comprising: a) at least one filtration element; b) at least one first passageway centrally disposed about the central axis of said housing, at least a portion of said first passageway being defined by a tubular member; c) at least one second passageway circumferentially disposed about said first passageway; d) a first end member connected to said first container end, said first end member comprising a conical flange supporting said tubular member; and e) a second end member connected to said second container end, said second end member connected to a plurality of channel ribs radially extending from the central axis within said housing, said channel ribs disposed between said first and second passage ways. 34. The assembly of claim 33 wherein said tubular member comprises a pressure relief valve assembly. 35. The assembly of claim 33 wherein a plurality of flange ribs are connected to said tubular member and said flange. 36. The assembly of claim 33 wherein said flange defines one or more inlet ports, said inlet ports being in fluid communication with said second passageway. 37. The assembly of claim 33 wherein said first passageway is also defined by a media support that supports said filtration element. 38. The assembly of claim 35 wherein said flange ribs are disposed on an exterior surface of said flange. 39. The assembly of claim 33 wherein said first end member and said tubular member are part of a monolithic unit. 40. The assembly of claim 35 wherein said flange, said flange ribs and said tubular member are part of a monolithic component. 41. The assembly of claim 33 wherein said second end member and said channel ribs are parts of one monolithic component. 42. The assembly of claim 33 wherein the housing is essentially cylindrical in shape.

Inventors: MICHALOWSKI RONALD F, PARNELL DOUGLAS R, MICHALOWSKI, RONALD, F., PARNELL, DOUGLAS, R.
Applicants: FILTERTEK INC, FILTERTEK INC.
Application year: 1997
Main classification: B01D35
IPC codes: B01D27, B01D29, B01D35, B01D46