Filter device for liquids and method of use

Abstract

The filter cartridge has a media construction, a housing, and a first end structure. The first end structure includes an outer radial wall having circumferentially spaced connectors, each connector having a plurality of helical profiles extending at a twist angle. The filter cartridge is removably mounted to a filter head having mating connector segments. A bowl cartridge assembly including connectors having a plurality of helical profiles is also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application was filed as a PCT international application on October 29, 2020, and claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 927,971, filed on October 30, 2019, the entire disclosure of which is incorporated by reference in its entirety.

[0002] The present disclosure relates to a liquid filter device that can be used, for example, to filter hydraulic fluids and lubricating fluids. A filter head is described in which a service-friendly filter cartridge device is positioned during use. Methods of assembly and use are also provided. [Background technology]

[0003] Circulating liquid systems, such as hydraulic and lubricating fluid systems, typically require a filter device. The filter device is typically positioned so that the fluid is filtered by passing through a filter media positioned within the filter device. The filter device is typically configured so that the components containing the media are replaceable, i.e., the media can be periodically removed and replaced.

[0004] There are two general types of liquid filter devices. The first type, referred to herein as the "spin-on" type, typically includes a filter head that is attached to the equipment and a spin-on filter element or cartridge. The filter element or cartridge is often referred to as "spin-on" because the assembly containing the filter media is typically secured to the filter head by a threaded engagement. In spin-on devices, the filter media is typically permanently secured within a shell or housing as a housing / media combination, and the entire housing / media combination is removed and replaced during maintenance as the filter element or cartridge.

[0005] A second common type of liquid filter device is referred to herein as a bowl / cartridge device. In a bowl / cartridge device, a filter head is also mounted on the device. However, the filter media is contained within a filter cartridge that is removably positioned within a housing or shell. The housing / cartridge combination is also mounted on the filter head for use. However, during maintenance, the housing is separated from the filter head, the media contained within the housing or shell is replaced, and then the same shell or housing with the replaced media therein is reinstalled on the filter head.

[0006] A properly functioning filter system is important in protecting downstream equipment such as an engine or hydraulic machinery. Improvements in filter systems are always desirable. Summary of the Invention [Means for solving the problem]

[0007] In one embodiment, a filter cartridge includes: (a) a treatment media structure having a first end and an opposite second end; (b) a first end structure adjacent the first end of the media structure, the first end structure including an outer radial wall and an axial wall, (i) the axial wall covering the first end of the media structure; and (ii) the outer radial wall having a plurality of connecting portions alternating with non-connecting portions; and (c) a filter housing having an enclosure wall defining an exterior, an interior, a bottom, and an opposite mouth, wherein (i) the filter housing is secured to the outer radial wall at the mouth, and (ii) the media structure is positioned within and spaced apart from the enclosure wall.

[0008] In various examples, the outer radial wall can overlaps a portion of the media structure; or the non-connecting portion is smooth; or the treatment media structure includes pleated media arranged in a tubular shape having an open interior volume; or the bottom of the filter housing is closed; or the non-connecting portions are equally spaced from one another; or the filter housing further includes a sealing member secured to the exterior of the filter housing; or the connecting portion of the outer radial wall is outside the filter housing; or the connecting portion of the outer radial wall is along an outer outer portion of the outer radial wall; or the connecting portion of the outer radial wall is along an inner portion of the outer radial wall; or each connecting portion has multiple helical profiles extending at a twist angle; or each helical profile within each connecting portion has a cross-sectional shape that is different from at least one other helical profile within the respective connecting portion.

[0009] In various examples, within each connection section, each helical profile is axially spaced apart from an adjacent helical profile, and the axial spacing between at least one helical profile and a second helical profile is different from the remaining axial spacings. Or, each connection section is identical to the other connection sections. Or, each connection section has at least four helical profiles. Or, there are at least three connection sections. Or, at least one connection section further includes a radially protruding stop member extending from the outer radial wall at a terminal end of at least one helical profile. Or, at least one spring-biased detent extending axially outward from the axial wall of the first end structure. Or, there are multiple spring-biased detents extending axially outward from the axial wall of the first end structure. Or, each spring-biased detent includes a leaf spring attached to the axial wall of the first end structure.

[0010] In various examples, the first end structure is part of a first end cap that is secured to a first end of the media structure, or the media structure further includes a second end cap that is secured to a second end of the media structure.

[0011] In an exemplary embodiment, (a) the outer radial wall of the first end structure includes a seal member seat having a pair of radially outwardly extending flanges with a wall portion therebetween, (b) the housing is attached to the outer radial wall by folding over at least a first of the flanges to cover the wall portion, and (c) the seal member is oriented radially outward relative to the housing in the seal member seat.

[0012] In various examples, the first end structure includes a hole communicating with the open interior volume. Or, the first end structure further includes a sealing member directed toward the hole. Or, the sealing member is a grommet. Or, a portion of the outer radial wall is axially spaced from the axial wall to define a plurality of circumferentially spaced gaps that define the fluid flow path. Or, the outer radial wall includes a plurality of circumferentially spaced connecting portions alternating with the gaps. Or, the outer radial wall has a continuous ring at an end distal from the axial wall, the continuous ring carrying the sealing member thereon. Or, each of the non-connecting portions is spaced apart from one another. Or, the filter housing is permanently secured to the outer radial wall at the mouth.

[0013] In another aspect, a filter cartridge includes: (a) a treatment media construction having a first end and an opposite second end; (b) a first end construction adjacent the first end of the media construction, the first end construction including an outer radial wall and an axial wall, (i) the axial wall overlies the first end of the media construction; (ii) the outer radial wall has a plurality of circumferentially spaced connections, each connection having a plurality of helical profiles extending at a twist angle; and (iii) each of the helical profiles within each connection has a cross-sectional shape that differs from at least one other helical profile within the respective connection; and (d) a filter housing having an enclosure defining an exterior, an interior, a bottom, and an opposite mouth, wherein: (i) the filter housing is secured to the outer radial wall at the mouth; and (ii) the media construction is positioned within and spaced apart from the enclosure.

[0014] In an exemplary embodiment, within each connection, each of the helical profiles is axially spaced from an adjacent helical profile, and the axial spacing between at least one helical profile and a second helical profile is different from the remaining axial spacings.

[0015] In another aspect, a filter cartridge includes: (a) a treatment media construction having a first end and an opposite second end; (b) a first end construction adjacent the first end of the media construction, the first end construction including an outer radial wall and an axial wall, (i) the axial wall overlies the first end of the media construction; (ii) the outer radial wall has a plurality of circumferentially spaced junctions, each junction having a plurality of helical profiles extending at a twist angle; and (iii) within each junction, each of the helical profiles is axially spaced from an adjacent helical profile, and the axial spacing between at least one helical profile and a second helical profile is different from the remaining axial spacings; and (d) a filter housing having an enclosure defining an exterior, an interior, a bottom, and an opposite mouth, wherein: (i) the filter housing is secured to the outer radial wall at the mouth; and (ii) the media construction is positioned within the enclosure and spaced from the enclosure.

[0016] In various examples, the connecting portions are separated by a plurality of non-connecting portions on the outer radial wall, and the non-connecting portions are spaced apart from one another. Alternatively, the outer radial wall overlaps a portion of the media structure. Alternatively, the treatment media structure includes pleated media arranged in a tubular shape having an open interior volume. Alternatively, the bottom of the filter housing is closed. Alternatively, the non-connecting portions are equally spaced apart from one another. Alternatively, the filter housing further includes a seal member fixed to the exterior of the filter housing. Alternatively, the connecting portions of the outer radial wall are outside the filter housing. Alternatively, the connecting portions of the outer radial wall are along an outer outer portion of the outer radial wall. Alternatively, the connecting portions of the outer radial wall are along an inner portion of the outer radial wall. Alternatively, each connecting portion is identical to the other connecting portions. Alternatively, each connecting portion has at least four helical profiles. Alternatively, there are at least three connecting portions. Alternatively, the filter housing further includes a radially protruding stop member extending from the outer radial wall at an end of at least one helical profile of the connecting portions.

[0017] In various examples, the first end structure further includes at least one spring-biased detent extending axially outward from the axial wall of the first end structure, or there are multiple spring-biased detents extending axially outward from the axial wall of the first end structure, or each spring-biased detent includes a leaf spring attached to the axial wall of the first end structure, or the first end structure is part of a first end cap and is secured to the first end of the media structure, or the first end structure further includes a second end cap secured to the second end of the media structure.

[0018] In some examples, (a) the outer radial wall of the first end structure includes a seal member seat having a pair of radially outwardly extending flanges with a wall portion therebetween, (b) the housing is attached to the outer radial wall by folding over at least a first of the flanges to cover the wall portion, and (c) the seal member is oriented radially outward relative to the housing in the seal member seat.

[0019] In various examples, the first end structure includes a hole communicating with the open interior volume. Alternatively, the first end structure further includes a sealing member directed toward the hole. Alternatively, the sealing member is a grommet. Alternatively, a portion of the outer radial wall is axially spaced from the axial wall to define a plurality of circumferentially spaced gaps that define the fluid flow path. Alternatively, the outer radial wall includes a plurality of circumferentially spaced connections alternating with the gaps. Alternatively, the outer radial wall has a continuous ring at an end distal from the axial wall, the continuous ring carrying the sealing member thereon. Alternatively, the filter housing is permanently secured to the outer radial wall at the mouth. Alternatively, each of the helical profiles in each connection has a cross-sectional shape that is different from at least one other helical profile in the respective connection.

[0020] In another aspect, a filtration assembly comprises (a) a filter cartridge as variously characterized above, and (b) a filter head removably attached to the filter cartridge to form a seal with a seal member of the filter cartridge.

[0021] In the example, the filter head includes (a) an end wall (36) and (b) a circumferential band extending axially from the end wall, the circumferential band including a plurality of circumferentially spaced connecting segments constructed and arranged to mate with connecting portions of the filter cartridge.

[0022] In various examples, the plurality of circumferentially spaced connecting segments are on an inner radial surface of the band, or the plurality of circumferentially spaced connecting segments are on an outer radial surface of the band, or the end wall includes an inner surface surrounded by the band, the inner surface of the end wall including one or more recesses positioned to receive the spring-biased detents.

[0023] In another aspect, a method of servicing a filtration assembly including a filter cartridge mounted on a filter head includes: (a) removing the filter cartridge from the filter head by rotating the cartridge relative to the head to disconnect connections on the cartridge from connection segments on the head; (b) providing a new filter cartridge having alternating circumferentially spaced connected and disconnected portions; (c) installing the new filter cartridge on the head by axially pushing the new filter cartridge and rotating the new filter cartridge by less than 90 degrees to engage the connections on the new filter cartridge with the connection segments on the filter head; and (d) compressing a seal member on the new filter cartridge to form a seal between the head and the new filter cartridge while rotating.

[0024] In examples, the step of providing a new filter cartridge includes providing a filter cartridge having smooth disconnections, each of the disconnections being equally spaced from one another, or the step of attaching the new filter cartridge to the head includes rotating the new filter cartridge until a stop member is engaged to prevent further rotation.

[0025] In another aspect, a method of servicing a filtration assembly including a filter cartridge attached to a filter head includes: (a) removing the filter cartridge from the filter head by rotating the cartridge relative to the head to disengage connections on the cartridge from connection segments on the head; (b) providing a new filter cartridge having connections, each connection having a plurality of helical profiles extending at a twist angle, each helical profile within each connection having a different cross-sectional shape than at least one other helical profile within the respective connection; (c) installing the new filter cartridge on the head by axially pushing the new filter cartridge and rotating the new filter cartridge by less than 90 degrees to engage the connections on the new filter cartridge with the connection segments on the filter head; and (d) compressing a seal member on the new filter cartridge to form a seal therebetween while rotating.

[0026] In another aspect, a method of servicing a filtration assembly including a filter cartridge attached to a filter head includes: (a) removing the filter cartridge from the filter head by rotating the cartridge relative to the head to disengage connections on the cartridge from connection segments on the head; (b) providing a new filter cartridge having connections, each connection having a plurality of helical profiles extending at a helix angle, wherein within each connection, each of the helical profiles is axially spaced from an adjacent helical profile and the axial spacing between at least one helical profile and a second helical profile is different from the remaining axial spacings; (c) installing the new filter cartridge on the head by axially pushing the new filter cartridge and rotating the new filter cartridge by less than 90 degrees to engage the connections on the new filter cartridge with the connection segments on the filter head; and (d) compressing a seal member on the new filter cartridge to form a seal therebetween while rotating.

[0027] In another aspect, a method of servicing a filtration assembly including a filter cartridge attached to a filter head includes: (a) removing the filter cartridge from the filter head by rotating the cartridge relative to the head to disengage connections on the cartridge from connection segments on the head; (b) providing a new filter cartridge having connections, each connection having a plurality of helical profiles extending at a helix angle, wherein within each connection, a first helical profile of the helical profiles differs from at least one other helical profile based on one or more of profile shape, axial spacing, or axial depth; (c) installing the new filter cartridge on the head by axially pushing the new filter cartridge and rotating the new filter cartridge less than 90 degrees to engage the connections on the new filter cartridge with the connection segments on the filter head; and (d) compressing a seal member on the new filter cartridge to form a seal therebetween while rotating.

[0028] In various examples, the step of installing the new filter cartridge in the head includes rotating the new filter cartridge until a stop member is engaged to prevent further rotation, and the rotating step includes rotating the new filter cartridge until a click is detected by the person performing the method. Or the click is one or both of an audible click and a tactile click. Or the rotating step until a click is detected includes rotating until a detent on the new filter cartridge is received within a detent recess in the head. Or the installing step includes aligning an outlet opening in the head with a grommet seal member on the new filter cartridge. Or the rotating step includes rotating the new filter cartridge until a stop member is engaged between the new filter cartridge and the head. Or the providing step includes providing a filter cartridge as variously characterized above.

[0029] In another aspect, a bowl cartridge assembly includes: (a) a filter cartridge having a media construction; and (b) a bowl having an outer radial wall and an interior volume, wherein the filter cartridge is removably mountable within the interior volume, the outer radial wall having a plurality of connections alternating with non-connections, and (i) each connection having a plurality of helical profiles extending at a helix angle, wherein within each connection, a first helical profile of the helical profiles differs from at least one other helical profile based on one or more of profile shape, axial spacing, or axial depth.

[0030] In various examples, the non-connected portions are smooth, or the media structure includes pleated media arranged in a tubular configuration with an open interior volume, or each of the non-connected portions is equally spaced from one another, or each connecting portion is identical to the other connecting portions, or each connecting portion has at least four helical profiles.

[0031] There are at least three connectors, or the filter cartridge further includes a radially protruding stop member extending from the outer radial wall at a terminal end of the helical profile of at least one of the connectors, or the filter cartridge includes a first end structure having an axial wall that covers the media structure.

[0032] In various examples, the first end structure further includes at least one spring-biased detent extending axially outward from the axial wall of the first end structure. Or, there are multiple spring-biased detents extending axially outward from the axial wall of the first end structure. Or, each spring-biased detent includes a leaf spring attached to the axial wall of the first end structure. Or, the first end structure is part of a first end cap, and the first end cap is secured to a first end of the media structure. Or, the first end cap further includes a second end cap secured to a second end of the media structure. Or, a portion of the outer radial wall is a filter cartridge radially spaced apart to define a plurality of circumferentially spaced gaps that define the fluid flow paths.

[0033] In another aspect, a filtration assembly includes (a) a bowl cartridge assembly as variously characterized above, and (b) a filter head removably attached to the filter cartridge to form a seal with a sealing member between the bowl cartridge assembly and the filter head.

[0034] In another aspect, a filter cartridge for use in a bowl-cartridge assembly includes: (a) a treatment media structure having a first end and an opposite second end; (b) a first end structure adjacent the first end of the media structure, the first end structure including an outer radial wall and an axial wall, the axial wall covering the first end of the media structure; and (c) a first plurality of circumferentially spaced radial projections extending from the outer radial wall, wherein: (i) the first plurality of radial projections have a first longitudinal length with terminal ends dimensioned to engage a rim of a filter bowl when the cartridge is inserted into the filter bowl; and (ii) the first plurality of radial projections are spaced apart from each other when the cartridge is inserted into the filter bowl. (d) a first plurality of circumferentially spaced radial projections having at least one lateral portion oriented to circumferentially abut a portion of the filter bowl when the cartridge is inserted into the filter bowl; (i) the second plurality of radial projections have a second longitudinal length that is shorter than the first longitudinal length; and (ii) the second plurality of radial projections are oriented to assist in precise rotational positioning of the cartridge within the filter bowl when the cartridge is inserted into the filter bowl; and (e) at least one spring-biased detent extending axially outward from the axial wall of the first end structure.

[0035] In examples, there are a plurality of spring-biased detents extending axially outward from the axial wall of the first end structure, or each spring-biased detent includes a leaf spring attached to the axial wall of the first end structure, or the first end structure is part of a first end cap, the first end cap being secured to a first end of the media structure, or the media structure further includes a second end cap secured to a second end of the media structure, or the treatment media structure includes pleated media arranged in a tubular configuration having an open interior volume.

[0036] In another aspect, a bowl cartridge assembly comprises: (a) a filter cartridge as variously characterized above; and (b) a bowl having an outer radial wall and an interior volume, wherein the filter cartridge is removably mountable within the interior volume, the outer radial wall having a plurality of connections alternating with non-connections, and (i) each connection having a plurality of helical profiles extending at a helix angle, wherein within each connection, a first helical profile of the helical profiles differs from at least one other helical profile based on one or more of profile shape, axial spacing, or axial depth.

[0037] In an exemplary embodiment, the outer radial wall and the axial wall are integral.

[0038] The present disclosure provides various features and techniques that can be implemented in liquid filtration systems, such as hydraulic or lubricant filtration systems, with selected techniques preferably applicable to spin-on filtration systems.

[0039] The described technology involves features incorporated into one or both of the filter head and / or the filter element that is removably attached to the filter head.

[0040] It is not necessary for all of the techniques described herein to be incorporated into a given system to obtain at least some benefits in that system. [Brief explanation of the drawings]

[0041] [Figure 1] 1 is a perspective view of a spin-on filter cartridge constructed in accordance with the principles of the present disclosure; [Figure 2] 2 is a cross-sectional view of a filter assembly including the filter cartridge of FIG. 1 connected to a filter head. [Figure 3] FIG. 2 is a perspective view of a portion of the filter cartridge of FIG. 1 with the outer housing removed. [Figure 4] FIG. 2 is an exploded perspective view of the filter cartridge of FIG. 1. [Figure 5] FIG. 2 is a plan view of a first end cap used with the filter cartridge of FIG. 1. [Figure 6] FIG. 6 is a perspective view of the first end cap of FIG. 5. [Figure 7] FIG. 7 is an enlarged dimensional view of a portion of the first end cap of FIGS. 5 and 6. [Figure 8] 2 is an enlarged cross-sectional view of a portion of the filter cartridge of FIG. 1. [Figure 9] FIG. 3 is a bottom perspective view of a filter head used in the filter assembly of FIG. 2. [Figure 10] 10 is another bottom perspective view of the filter head of FIG. 9. [Figure 11] FIG. 11 is another bottom perspective view of the filter head of FIGS. 9 and 10. [Figure 12] 12 is a partial cross-sectional view of a filter assembly showing the filter cartridge of FIG. 1 removably mounted in the filter head of FIGS. 9-11. [Figure 13] FIG. 10 is an exploded perspective view of another embodiment of a filter assembly, similar to the assembly of FIG. 2 except that the filter head connection segments are along the outer radial surface of the filter head and the filter cartridge connection segments are along the inner wall of the cartridge. [Figure 14] 14 is a schematic cross-sectional view of a portion of the filter assembly of FIG. 13, illustrating the connection between the filter head and the filter cartridge. [Figure 15] 14 is a schematic cross-sectional view of a portion of the filter assembly of FIG. 13, showing a portion of the interface between the filter head and the filter cartridge. [Figure 16] 1 is a perspective view of a filter cartridge constructed in accordance with the principles of the present disclosure; [Figure 17] FIG. 17 is a perspective view of a filter bowl used with the filter cartridge of FIG. 16. [Figure 18]18 is a perspective view of the filter cartridge of FIG. 16 during a step of being attached to the filter bowl of FIG. 17. FIG. [Figure 19] FIG. 18 is a perspective view showing the filter cartridge of FIG. 16 fully installed in the filter bowl of FIG. 17. [Figure 20] 9 is a view similar to FIG. 8 illustrating an alternative embodiment of a portion of a filter cartridge used herein. [Figure 21] 21 is another view similar to FIGS. 8 and 20 illustrating another alternative embodiment of a portion of a filter cartridge used herein. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0042] 2, reference numeral 20 generally designates a liquid filter assembly according to the present disclosure. The liquid filter assembly 20 includes a filter head 22 and a filter cartridge 24. The filter head 22 is typically mounted to equipment in a liquid line, such as a hydraulic line or a lubricating fluid (lube oil) line. During maintenance, the filter head 22 typically remains in place on the equipment.

[0043] The filter cartridge 24, in turn, is removably mounted on the filter head 22. Maintenance is provided by replacement of the media contained within the filter cartridge 24. The filter cartridge 24 shown herein is a spin-on type filter cartridge. Thus, during maintenance, the entire filter cartridge 24, including the media and outer housing, is removed and discarded and replaced with a completely new filter cartridge 24.

[0044] 2 shows a central longitudinal axis 26 about which filter assembly 20 is positioned. The terms "axial," "axially," and variations thereof, as used herein, are intended to generally refer to features extending in the general direction of axis 26. The terms "radial," "radially," and variations thereof, are intended to refer to directions toward or away from axis 26.

[0045] 2, filter head 22 includes a liquid flow inlet 28 and a liquid flow outlet 30. During operation, liquid to be filtered is directed into filter head 22 through inlet 28. The liquid is then directed through filter cartridge 24 for filtration. The filtered liquid is then returned to filter head 22 and discharged through outlet 30.

[0046] In a typical system, the filter head 22 comprises a cast metal section, for example, cast aluminum, with various additional features.

[0047] Although many embodiments are possible, in the embodiment shown, filter head 22 includes a flange 32 that may have bolt holes 34, 35 for securing the filter in 22 to equipment.

[0048] An end wall 36 is secured to the flange 32. The end wall 36 typically includes an inlet opening 38 in communication with the inlet 28 to allow liquid to flow from the filter head 22 to the cartridge 24. The end wall 36 also has an outlet opening 40 to allow filtered liquid to flow from the cartridge 24 to the filter head 22 and out through the main outlet 30.

[0049] Extending axially from end wall 36 is a circumferential band 42. Band 42 has a surrounding wall 44 having an outer surface 46 and an opposite inner or inner radial surface 48. Inner radial surface 48 includes a system that allows for selective attachment and detachment between filter head 22 and filter cartridge 24, which will be discussed further below.

[0050] The filter cartridge 24 is shown in perspective view in Figure 2 and in cross section in Figure 2 connected to the filter head 22. The filter cartridge 24 includes a filter housing 50. The filter housing 50 includes an outer can or shell 52 having an enclosure 54. The enclosure 54 has an exterior surface 56 and an opposing interior surface 58. There is a closed bottom 60 and an opposing mouth 62 that interfaces with the filter head 22.

[0051] Shell 52 may include a plurality of anti-slip dimples 53 spaced circumferentially around shell 52 adjacent mouth 62. Dimples 53 aid in allowing a user to grip cartridge 24 during installation or removal of cartridge 24 and filter head 22.

[0052] Typically, the outer shell 52 comprises metal components. The housing 50 defines an interior volume 64. Within the interior volume 64, a filter media construction 66 is positioned. The filter media construction 66 comprises a filter media 68 positioned in an extension between a second (lower) end cap 70 and a first (upper) end structure 71. The end structure 71 is adjacent to a first end of the media construction 66 and may be part of the first end cap 72 secured to the media construction 66. The media 68 may comprise a variety of materials selected for the particular operation and conditions to be encountered. Typically, the filter media 68 is provided in a pleated configuration, although alternative configurations are possible. Various types or shapes of media or media pleats may be used. Adhesive beads, for example, may help maintain media integrity and pleat spacing. In some alternative arrangements, the media 68 may be covered with a plastic or wire mesh screen, if desired.

[0053] The filter media construction 66 may be tubular in shape and configured around and defining an open filter interior volume 74. An internal media support 76 is positioned within the open filter interior volume 74 and, in this example, comprises a porous liner extending along the media 68 between and secured to the end caps 70, 72.

[0054] Although alternatives are possible, in the example shown, second end cap 70 is a closed end cap, meaning that it has a closed center that prevents the passage of unfiltered liquid. Tubular filter media structure 66 has a first end 80 that is secured to first end cap 72 and an opposite second end 82 that is secured to second end cap 70. Media 68 is secured to second end cap 70 by a variety of methods, including adhesive or potting, or by molding media 68 in place. A variety of materials can be used for end cap 70, including metal or plastic.

[0055] On the other hand, first end cap 72 is typically an open end cap defining a central flow hole 84 therethrough. Hole 84 is positioned so as to be in direct flow communication with interior 74 of media 68. As used herein, the term "direct flow communication" is intended to refer to a passageway capable of flow communication with interior 74 without requiring a flow path through media 68. That is, liquid within interior 74 can flow directly through hole 84 without simultaneously passing through media 68. Of course, in the first example for an "outside-in" flow device as described, liquid would not reach interior 74 without first passing through media 68.

[0056] As shown, the illustrated filter cartridge 24 is configured for outside-to-in flow during filtration. This means that unfiltered liquid is directed from the filter head 22 into the annulus 86 around the media 68 and between the inner surfaces 58 of the walls 54, then through the media 68, through the support 76, and into the interior 74. Filtered liquid is directed upward through the central flow hole 84 in the first end cap 72, back to the filter head 22 through the outlet opening 40, and then out through the outlet 30.

[0057] It should be noted that many of the principles described herein can be utilized in connection with an "inside-out" flow device in which the flow direction of the liquid to be filtered is reversed, i.e., through holes 84 into interior 76, through media 68 into annulus 86, and then back into filter head 22.

[0058] Generally, a sealing arrangement is required between the filter cartridge 24 and the filter head 22 to prevent the liquid flow from bypassing the media 68 as it is directed through the filter cartridge 24. Such a sealing arrangement is provided by a seal member 88 on the cartridge 24 to form a seal between the cartridge 24 and the filter head 22.

[0059] 3-7, there is shown first end structure 71, either by itself or with other features. First end structure 71 includes outer radial wall 90. Outer radial wall 90 extends along at least a portion of the length of filter media construction 66 in a direction from first end 80 toward second end 82. Outer radial wall 90 covers or overlaps a portion of media construction 66. While many examples are possible, in the example shown, outer radial wall 90 overlaps less than 25% and more than 5% of the total length of the filter media construction between first end 80 and second end 82.

[0060] 8, an outer radial wall 90 of the first end structure 71 is shown enlarged. The outer radial wall 90 defines a seal member seat 92 that retains the seal member 88. In the example shown, the seal member seat 92 has a pair of radially outwardly extending flanges 94, 95 having a wall portion 96 therebetween. The seal member 88 is positioned between the flanges 94, 95.

[0061] Further, with reference to FIG. 8 , it can be seen how the housing 50 is attached to the first end structure 71. While many different techniques are available, in the example shown, the housing 50 is attached to the outer radial wall 90. In particular, the housing 50 is permanently secured or fixed to the outer radial wall 90 by folding it over at least a first flange 95. The housing 50 can cover at least a portion of the wall 96 between the flanges 94, 95. In some embodiments, the housing 50 can similarly fold over at least a portion of the second flange 94, completely covering the wall 96 at the fold 97. In FIG. 8 , the seal member 88 is oriented radially outward relative to the housing 50 at the seal member seat 92. In the example shown, the housing 50 is sandwiched between the seal member 88 and the wall 96 of the outer radial wall 90 of the first end structure 71.

[0062] First end structure 71 further includes an axial wall 100. Axial wall 100 covers first end 80 of media structure 66. Generally, outer radial wall 90 extends at an angle of approximately 90° relative to axial wall 100. Axial wall 100 defines central flow bore 84. Central flow bore 84 may further receive a seal member, such as a grommet seal member 102 therein, for connection with filter head 22, e.g., the portion of filter head 22 that defines outlet opening 40.

[0063] First end structure 71, in the exemplary embodiment shown, includes a plurality of circumferentially spaced apart non-connecting portions 107, indicated in the exemplary view at 107a, 107b, and 107c. Non-connecting portions 107 are generally along outer radial wall 90, either as complete gaps (no wall structure at all), or as smooth portions of wall 90, or as portions of wall 90 that do not interfere with filter head 22 when filter head 22 is attached to cartridge 24. In a preferred embodiment, non-connecting portions 107 are equal in circumferential length and equally spaced from one another. In this case, when there are three non-connecting portions 107a, 107b, and 107c, they are spaced 60° apart from one another.

[0064] In accordance with the principles of the present disclosure, the filter cartridge 24 includes a system that allows for low-friction installation of the cartridge 24 into the filter head 22, including simple insertion and less than a full rotation of the cartridge. In this embodiment, the system includes a connection system 104. The connection system 104 allows for low-friction insertion and rotation of the cartridge 24 of less than 180°, e.g., approximately 60°. The connection system 104 eliminates cross-threading and is suitable for having connectors unique to a particular customer.

[0065] In the exemplary embodiment shown, connection system 104 includes a plurality of circumferentially spaced connections, shown herein as 106, 108, and 110. Each connection 106, 108, 110 includes a plurality of helical profiles 112, 113. There are at least two helical profiles 112, 113, and there can be more than two helical profiles, for example, three helical profiles 112, 113, 114. In the example shown, there are four helical profiles 112, 113, 114, 115 (FIG. 8).

[0066] Each of the helical profiles 112, 113, 114, 115 extends along and protrudes from the outer radial wall 90. By "helical profile" is intended a geometric profile along the outermost boundary that, when continuous, has a general helical shape. A helical profile is not a thread. In a helical profile, a plane perpendicular to the central longitudinal axis passes through more than one profile, whereas in a thread, a plane perpendicular to the central longitudinal axis passes through only one thread form.

[0067] Referring to Figure 8, in the embodiment shown, there are four helical profiles 112, 113, 114, and 115. As can be seen in Figure 7, the helical profiles 112-115 extend with a twist angle 116. By the term "twist angle" is meant the angle of each of the helical profiles 112-115 relative to a plane perpendicular to the longitudinal axis 26. In Figure 7, the twist angle is indicated by the reference numeral 116. Each of the helical profiles 112-115 preferably has the same twist angle 116, although in other embodiments, the twist angle 116 can vary for each of the helical profiles 112-115.

[0068] In FIG. 12, 118c indicates the amount of seal compression, which is affected by the twist angle 116.

[0069] Each of the helical profiles 112-115 is axially spaced apart from an adjacent helical profile 112-115. By "axial spacing" is meant the spacing between the load-bearing surfaces of each of the profiles 112-115. The "load-bearing" surfaces are the surfaces that face the threads of the filter head when connected. The load-bearing surfaces are shown in this embodiment as 112a, 113a, 114a, and 115a in FIG. 20. The axial spacing between each of the individual helical profiles 112-115 can be the same or different. In the illustrated embodiment, the spacing is different. For example, FIGS. 8 and 20 show the axial distance between connections 112 and 113 at D1, the distance between connections 113 and 114 at D2, and the distance between connections 114 and 115 at D3. In some embodiments, each of D1, D2, and D3 can be equal, but in many preferred embodiments, each of D1, D2, and D3 is a different value.

[0070] Each of the helical profiles 112-115 has a cross-sectional shape. The cross-sectional shapes of each of the helical profiles 112-115 can all be the same or, preferably, can be different from one another. Preferably, each of the helical profiles 112, 115 in each connection 106, 108, 110 has a cross-sectional shape that is different from at least one other helical profile 112-115 in the respective connection 106, 108, 110.

[0071] 8 and 20, the top helical profile 112 has a trapezoidal shape, in which one of the non-parallel sides 112a is contained in a plane perpendicular to the longitudinal axis 26, and the other of the non-parallel sides 112b is angled relative to that same plane. Helical profile 113 is shown to be rectangular, which could be square. Helical profile 114 is shown to be trapezoidal, in which both non-parallel sides are angled relative to a plane perpendicular to the longitudinal axis 26. Helical profile 115 is shown to be round in cross section. These are merely examples, and it should be understood that there are many, many different shapes and combinations that can be used. In fact, each customer of these cartridges 24 can request their own specific "code" of helical profiles.

[0072] FIG. 21 illustrates alternative helical profile combinations, including different axial depths of the profile's load-bearing surfaces. In the example of FIG. 21, there are three helical profiles 312, 313, and 314, which differ in shape, axial spacing, and load-bearing depth. All three helical profiles 312, 313, and 314 are trapezoidal, but they are differently shaped trapezoids. The axial spacing between profiles 312a and 313a is indicated by D1, while the axial spacing between profiles 313a and 314a is indicated by D2. D1 differs from D2, with D1 being greater than D2. The axial depths are indicated by H1, H2, and H3, measured from the base of each axial support surface 312a, 313a, and 314a and the terminal (free) end of each helical profile 312, 313, and 314. The axial depths H1, H2, and H3 are different from each other in this exemplary embodiment.

[0073] From inspection of Figures 8, 20, and 21, it should be appreciated that when selecting a combination of helical profiles, at least one (or more) of the helical profiles can vary from at least one other of the helical profiles by at least one of profile shape, axial spacing, and / or axial depth, and / or any combination of these characteristics.

[0074] Preferably, each connection 106, 108, 110 is identical to the other connections 106, 108, 110. This means that when installing the cartridge 24 onto the filter head 22, the user does not need to worry about matching the exact connection 106, 108, 110 to a particular receiving connection segment on the filter head 22. The filter cartridge 24 is constructed such that the filter housing 50 is permanently secured to the outer radial wall 90 at the mouth 62, and the connections 106, 108, 110 of the outer radial wall 90 are outside the filter housing 50. In fact, the connections 106, 108, 110 are located axially above the terminal end 98 (FIG. 8) of the housing 50.

[0075] Preferably, outer radial wall 90 has a plurality of alternating, circumferentially spaced connecting portions 106, 108, 110 and smooth non-connecting portions 107a, 107b, 107c. Connecting portions 106, 108, 110 may be interrupted by short sections that do not form a connection with filter head 22; generally, in a preferred example, non-connecting portion 107 has no structure along radial wall 90 that forms a connection or attachment with filter head 22, although alternative structures are possible. Any interruptions in connecting portions 106, 108, 110 that do not form a connection with filter head 22 are not considered within the definition of "non-connecting portion."

[0076] 9-11, the filter head 22 is shown in further detail. The inner radial surface 48 of the filter head 22 includes a plurality of circumferentially spaced connector segments 122, 124, 126 constructed and arranged to mate with the connector portions 106, 108, 110 of the filter cartridge 24. Attention is directed to FIG. 12, where it can be seen how the connector segments 122, 124, 126 mate with the connector portions 106, 108, 110. In particular, each of the connector segments 122, 124, 126 has a profile 128 that is a mirror image of the profile shape of the connector portions 106, 108, 110. Thus, the profile 128 includes a recess having the same cross-sectional shape as the helical profiles 112-115. For example, the profile 128 has an uppermost profile recess 130 that has a shape that mates with the trapezoidal shape of the helical profile 112. Similarly, profile recess 131 has a rectangular shape that mates with the cross-sectional shape of helical profile 113. Profile recess 132 has a trapezoidal shape that matches the shape of helical profile 114, while profile recess 133 has a round shape that receives rounded helical profile 115. Naturally, as the cross-sectional shapes of helical profiles 112-115 change, the corresponding profile recesses 130-133 will change as well.

[0077] As can be seen in FIGS. 9-11, the connecting segments 122, 124, 126 are circumferentially spaced along the inner radial surface 48 and are separated by smooth, non-grooved portions 135, 136, 137 of the inner radial surface 48.

[0078] 5 and 6, one preferred first end structure 71 is shown. The first end structure 71 is constructed and arranged to have an inlet arrangement 140. The inlet arrangement 140 includes a plurality of fluid flow passages 142, which in the exemplary embodiment may be inlet openings 142 in the first end structure 71. Upon entering the filter assembly 20, the fluid to be filtered flows through the inlet 28 into the filter head 22, exits the filter head 22 through the inlet openings 38, and enters the filter cartridge 24. The filtered fluid enters the annulus 86 of the cartridge 24 by flowing through the inlet openings 142 in the first end structure 71.

[0079] In this embodiment, the outer radial wall 90 of the first end structure 71 is spaced from and attached to the axial wall 100 to define a plurality of circumferentially spaced gaps 144 therebetween. The gaps 144 function as inlet openings 142. In the preferred embodiment shown, the circumferentially spaced connections 106, 108, 110 alternate with open gaps 144 in the outer radial wall 90. The gaps 144 correspond to the non-connections 107. The outer radial wall 90 has a continuous-walled ring 146 at its distal end 148 from the axial wall 100. The continuous ring 146 is continuous in that it surrounds and forms the entire circumference of the first end structure 71. The continuous ring 146 carries the seal member 88 thereon.

[0080] In the exemplary embodiment, a gap 144 forming the inlet opening 142 is between the ring 146 and the disconnected portions 107a, 107b, 107c.

[0081] The filter cartridge 24 may further include a stop member 150. The stop member 150 provides an engagement surface on a portion of the filter head 22 for abutting or engaging when the filter cartridge 24 is installed and secured to the filter head 22. The stop member 150 provides feedback to a user that the cartridge 24 is fully engaged onto the filter head 22 through the engagement of the connecting portions 106, 108, 110 and the connecting segments 122, 124, 126. The engagement between the filter head 22 and the stop member 150 prevents further rotation of the filter cartridge 24 relative to the filter head 22.

[0082] In the embodiment shown, the stop member 150 projects radially from the outer radial wall 90 of the first end structure 71. In the exemplary embodiment shown, the stop member 150 extends from the outer radial wall 90 at the terminal end of at least one helical profile 112-115 of the connecting portions 106, 108, 110. In the example shown in Figures 5 and 7, there is only a single stop member 150 on the first end structure 71. In some embodiments, a stop member 150 can extend from the terminal end of each of the connecting portions 106, 108, 110.

[0083] The helical profiles 112-115, in some variations, may include ridges protruding toward the ends of the profiles that are engaged just prior to full installation between the filter head 22 and the cartridge 24. The ridges require additional torque at the end of the installation process between the connecting segments 122, 124, 126 and the connections 106, 108, 110. The ridges help prevent unintentional disconnection between the filter head 22 and the cartridge 24, for example, due to vibration.

[0084] In accordance with the principles of the present disclosure, filter cartridge 24 can further include at least one spring-biased detent 160. Detent 160 extends axially outward from axial wall 100 of first end structure 71. In many preferred embodiments, and in the embodiment shown, there are multiple spring-biased detents 160, 161, 162, each extending axially outward from axial wall 100 of first end structure 71. Spring-biased detents 160, 161, 162 are circumferentially spaced from one another and are radially outward of central flow hole 84 and radially inward of inlet opening 142.

[0085] Each spring-biased detent 160, 161, 162 includes a spring, such as a leaf spring 171, 172, 173, attached to the axial wall 100 that allows for resilient deflection of the detents 160, 161, 162 in the axial direction.

[0086] The detents 160, 161, 162 are received by detent recesses 164, 165, 166 defined in the inner surface 176 of the end wall 36 of the filter head 22. The interaction between the detents 160-162 and the detent recesses 164-166 provides feedback, such as an audible "click," that notifies the user that the filter cartridge 24 is properly installed on the filter head 22. The detents 160, 161, 162 also help prevent the filter cartridge 24 from loosening from the filter head 22 due to vibration during operation. In addition to being audible, the feedback can also be tactile, in that the user can sense when the detents 160-162 are in the recesses 164-166.

[0087] An alternative embodiment of filter assembly 20 is shown at 20' in Figures 13-15. The structure and features of assembly 20' are the same as those of assembly 20, and those descriptions and features will not be repeated here but are instead incorporated herein by reference. The difference between assembly 20 and assembly 20' is that a plurality of circumferentially spaced connector segments 122' are located on an outer radial surface 200 of band 42' filter head 22', while the connector 106' of filter cartridge 24' is located along an inner wall 202 of end cap 72'. End cap 72' has a surrounding wall 204 that is radially outward of the outer diameter of filter media 68'. Surrounding wall 204 includes an extension 206 that projects axially from first end 80' of media 68' in a direction opposite media 68'. A volume 208 within extension 206 between end cap 72' and a terminal end 210 of extension 206 is sized to receive band 42' of filter head 22'.

[0088] 14 and 15, it will be understood that the enclosure 54 of the canister 52 is permanently attached to the remainder of the cartridge 24'. In the example shown, the canister 52 is attached to the end cap 72' by being folded or crimped at a crimp 212 on the terminal end 210 of the end cap extension 206.

[0089] The axial wall 100' of the end cap 72' may include detents, such as 160', 162', protruding therefrom. The detents 160', 162' are received within detent recesses in the filter head 22' and provide feedback in the form of an audible or tactile click sensation.

[0090] A seal member 102', which provides a seal between the unfiltered flow on the inlet (dirty) side of the media 68' and the outlet (clean) side of the media 68', can be seen in Figures 14 and 15. The seal member 102' is located around the outlet 84' of the cartridge 24'. In the filter head 22', unfiltered liquid flows into the cartridge 24' through an unfiltered liquid port 220. After flowing through the media 68', the filtered liquid returns to the head 22' through a filtered liquid port 222.

[0091] An alternative embodiment of the bowl cartridge assembly is shown in Figures 16-19 at 402. Bowl cartridge assembly 402 includes a filter cartridge 404 and a filter bowl 406.

[0092] Filter cartridge 404 is insertable, removable, and replaceable within filter bowl 406. Filter bowl 406 is removably connected / attached to a filter head, such as filter head 22 of Figures 9 and 10. Figure 18 shows filter cartridge 404 partially attached to interior 408 of filter bowl 406, and Figure 19 shows filter cartridge 404 fully attached and positioned within interior 408 of filter bowl 406.

[0093] The filter cartridge 404 can vary. In the example shown, the filter cartridge 404 has a tubular (e.g., cylindrical) section of pleated filter media 410. At opposite ends of the filter media 410 are first and second end structures or end caps 412, 414. The first end cap 412 is an open end cap having a through opening 416 that communicates with the interior of the pleated filter media. The second end cap 414 can be open or closed. It can have a seal member 417 surrounding the opening 416.

[0094] First end cap 412 can include at least one, and in the illustrated example, a plurality of, spring-biased detents 420, 421, 422 each extending axially outward from axial wall 419 of first end cap 412. Spring-biased detents 420, 421, 422 are similar to detents 160, 161, 162, and the descriptions of 160, 161, 162 apply to detents 420, 421, 422 and will not be repeated again. Detents 420, 421, 422 are received by detent recesses 164, 165, 166 defined in inner surface 176 of end wall 36 of filter head 22, for example, to provide feedback, such as an audible “click,” to indicate to a user that filter cartridge 404 is properly installed on filter head 22 and further prevent filter cartridge 404 from loosening from filter head 22 due to vibration during operation. In addition to being audible, the feedback can also be tactile.

[0095] First end cap 412 includes a first plurality of circumferentially spaced radial projections 430 extending radially from an outer periphery 413 of first end cap 412. First plurality of radial projections 430 have a first longitudinal length with terminal ends 431 dimensioned to engage rim 432 filter bowl 406 when cartridge 404 is inserted into filter bowl 406.

[0096] First plurality of radial projections 430 have at least one lateral (or transverse) portion 433 oriented to circumferentially abut a portion of filter bowl 406 when cartridge 404 is inserted into bowl 406. As shown in Figures 18 and 19, lateral portion 433 circumferentially engages side edges 434 of spaced apart connecting portions 446, 448, and 450 (described below) that assist in angularly positioning or metering spring-loaded detents 420, 421, 422 relative to filter head 22. By engaging side edges 434 of connecting portions 446, 448, and 450, radial projections 430 also prevent rotation of cartridge 404 within bowl 406.

[0097] The first end cap 412 further includes a second plurality of circumferentially spaced radial protrusions 435 extending from the outer radial wall 413. The second plurality of radial protrusions 435 have a second longitudinal length that is shorter than the first longitudinal length of the first radial protrusions 430.

[0098] Second plurality of radial projections 435 are oriented to assist in precise rotational positioning of cartridge 404 within filter bowl 406 when cartridge 404 is inserted into filter bowl 406. Second radial projections 435 interfere with connections 446, 448, and 450, thereby preventing cartridge 404 from being inserted into bowl 406 unless it is properly aligned with bowl 406.

[0099] In accordance with the principles of the present disclosure, filter bowl 406 includes outer radial wall 407 forming an enclosure defining interior volume 408 therein. Filter bowl 406 has a system that allows for low-friction installation of bowl cartridge assembly 402 into filter head 22, including simple insertion and less than a full rotation of assembly 402. In this embodiment, the system includes connection system 440, similar to system 104 described above and not repeated here. Connection system 440 operates like system 104, allowing for low-friction insertion and rotation of assembly 402 of less than 180°, e.g., approximately 60°. Connection system 440 eliminates cross-threading and is suitable for having connectors specific to a particular customer. Connection system 440 is mounted on outer radial wall 407.

[0100] Connection system 440 is shown herein as 446, 448, and 450 and includes a plurality of circumferentially spaced connection sections similar to connection sections 106, 108, 110, and has a plurality of helical profiles 452, 453, 454 similar to helical profiles 112, 113, 114. Helical profiles 452, 453, 454 can have various characteristics as described above in connection with Figures 8, 20, and 21, which descriptions are incorporated herein by reference and will not be repeated again here.

[0101] When the filter cartridge 404 is attached to the bowl 406, flow gaps 462, 464 are formed between the filter cartridge 404 and the filter bowl 406. The flow gaps 462, 464 also circumferentially extend between adjacent connections 446, 448, 450. When secured to the filter head 22, the flow gaps 462, 464 can provide flow passageways for the inlet fluid stream to be filtered. The fluid to be filtered flows from the filter head 22, into the filter assembly 402, and through the flow gaps 462, 464. The fluid then flows radially through the filter media 410 (which removes impurities from the fluid) and into the filter interior. From there, the fluid exits the filter assembly 402 by flowing through the openings 416 in the first end cap 412 and returns to the filter head 22. After a period of use, the filter cartridge 404 can be removed from the bowl 406 and replaced with a new filter cartridge 404. Bowl 406 is attached to filter head 22 by mating connection system 440 as described above with respect to system 104 .

[0102] Bowl cartridge assembly 402 can be used with a filter head, such as filter head 22, to form a filter assembly.

[0103] A method for servicing the filter assembly 20 can be implemented using the principles described above. After a period of operation, the filter cartridge 24 requires servicing by replacing the cartridge 24 due to clogging of the filter media 68. To service the filter assembly 20, the old filter cartridge 24 is removed from the filter head 22 and discarded. To remove the old filter cartridge 24 from the filter head, the cartridge 24 is rotated relative to the filter head 22, preferably by hand and without the use of tools. The cartridge 24 is rotated to disengage the connections 106, 108, and 110 from the connecting segments 122, 124, and 126. This also releases the seal member 88, allowing the cartridge 24 to be pulled axially away from the filter head 22.

[0104] A new filter cartridge 24 with new media 68 is then provided. The new filter cartridge 24 is installed in the filter head 22 by aligning the outlet opening 40 of the filter head 22 with the grommet seal member 102 of the cartridge 24. The cartridge 24 is pushed axially toward the filter head 22 and then rotated less than 90°, typically 60° or less. The cartridge 24 is rotated so that the connections 106, 108, 110 engage or mate with the connection segments 122, 124, 126. The cartridge 24 can rotate until the stop member 150 prevents further rotation of the cartridge 24 within the filter head 22. As the cartridge 24 is rotated within the filter head 22, the seal member 88 is compressed to form a seal between the filter head 22 and the cartridge 24. During the rotation step, cartridge 24 rotates until detents 160, 161, 162 are received within detent recesses 164, 165, 166 and feedback in the form of an audible or tactile click sensation is detected by the user. This ensures that filter cartridge 24 is properly attached to filter head 22 and filter assembly 20 is once again ready to filter.

[0105] The above represents exemplary principles, and many embodiments can be constructed using these principles.

Claims

1. (a) a treatment media structure having a first end and an opposite second end; (b) a first end structure adjacent the first end of the treatment media structure, (c) the first end structure includes an outer radial wall and an axial wall; (i) the axial wall covers the first end of the treatment media structure; (ii) the outer radial wall has a plurality of circumferentially spaced connecting portions, each connecting portion having a plurality of helical profiles extending at a helix angle; (iii) within each connection, each of the helical profiles is axially spaced from an adjacent helical profile, and the axial spacing between at least one helical profile and a second helical profile is different from the remaining axial spacings; a first end structure; and (d) a filter housing having an enclosure defining an exterior, an interior, a bottom, and an opposing mouth; (i) the filter housing is secured to the outer radial wall at the mouth; (ii) the treatment media structure is positioned within the interior of the enclosure and spaced apart from the enclosure; Filter housing and A filter cartridge comprising:

2. The filter cartridge of claim 1 , wherein the connecting portions are separated by a plurality of non-connecting portions on the outer radial wall, the non-connecting portions being spaced apart from one another.

3. The filter cartridge of claim 1 further comprising a radially protruding stop member extending from the outer radial wall at a terminal end of the helical profile of at least one of the connections.

4. The filter cartridge of claim 1 , further comprising at least one spring-biased detent extending axially outward from the axial wall of the first end structure.

5. 5. The filter cartridge of claim 1, wherein portions of the outer radial wall are axially spaced from the axial wall to define a plurality of circumferentially spaced gaps that define fluid flow paths.

6. 6. The filter cartridge of claim 1, wherein each of the helical profiles within each connection has a cross-sectional shape that differs from at least one other helical profile within the respective connection.

Images