WO2009039285A1

WO2009039285A1 - Air cleaner arrangements: components thereof; and methods

Info

Publication number: WO2009039285A1
Application number: PCT/US2008/076870
Authority: WO
Inventors: Steven K. Campbell
Original assignee: Donaldson Company, Inc.
Priority date: 2007-09-19
Filing date: 2008-09-18
Publication date: 2009-03-26

Abstract

A filter element is provided according to the invention. The filter element 230 includes a media pack, a seal member 250, a ring member 260, and a first fastener 270 and a second fastener. The media pack has an inlet flow face and an opposite outlet flow face. The media pack comprises a plurality of flutes extending between the inlet flow face and the outlet flow face. The media pack is closed to passage of unfiltered air therethrough between the inlet flow face and the outlet flow face. The seal member 250 is constructed to provide a seal between the media pack and a clean air outlet housing. The ring member 260 is positioned on the media pack and includes a first side and an opposite second side. The first fastener is attached to the first side of the ring member, and the second fastener is attached to the second side of the ring member.

Description

AIR CLEANER ARRANGEMENTS: COMPONENTS THEREOF; AND METHODS

This application is being filed on 18 September 2008, as a PCT International Patent application in the name of DONALDSON COMPANY, INC., a U.S. national corporation, applicant for the designation of all countries except the U.S., and Steven K. Campbell, a citizen of the U.S., applicant for the designation of the U.S. only, and claims priority to U.S. Provisional Patent Application Serial No. 60/994,368 filed on 19 September 2007.

Field of the Disclosure The present disclosure concerns air cleaners for use, for example, for cleaning engine combustion air for vehicles and other equipment. The disclosure provides preferred embodiments, assemblies, and methods.

Background of the Invention

Gas streams often carry particulate material therein. In many instances it is desirable to remove some or all of the particulate material from the gas flow stream. For example, air intake streams to engines for motorized vehicles or power generation equipment often include particulate material therein. The particulate material, should it reach the internal workings of the mechanisms involved, can cause substantial damage. It is therefore preferred, for such systems, to remove the particulate material from the gas flow upstream of the engine or other equipment involved. A variety of air cleaner arrangements have been developed for particulate removal.

There has been a general trend for the utilization of air cleaner arrangements that utilize, as a media pack, z-fϊlter media constructions. In general z-filter media constructions can be characterized as comprising fluted media sheet material secured to a facing media sheet material, formed into a media pack configuration. Examples of z-filter arrangements are described in PCT Publication WO 97/40918, published November 6, 1997; U.S. patents 6,190,432 and 6,350,291; PCT application US 04/07927, filed March 17, 2004; U.S. Provisional application 60/532,783, filed December 22, 2003; PCT Publication 03/095068, published

November 20, 2003; PCT publication WO 04/007054, published January 22, 2004;

PCT publication WO 03/084641, published October 16, 2003; and, U.S. Provisional Application 60/543,804, filed February 11, 2004; the complete disclosures of each of these cited references being incorporated herein by reference.

Serviceable filter elements or filter cartridges in an air cleaner arrangement are typically replaced with a new filter element or filter cartridge after a specified period of use or once the pressure drop through the filter element reaches a predetermined level. Replacement of an old filter element with a new filter element raises certain issues for the technician replacing the filter elements. For example, the technician needs to be sure that the filter element is correctly situated within the air cleaner so that there are no leaks or areas for unfiltered air to bypass the filter element. As a result, is desirable to provide a convenient technique for changing a filter element, and to provide feedback so that the operator can know that the filter element has been correctly installed.

Selected components described herein are improvements in such air cleaner arrangements as those described in U.S. Provisional Application 60/567,121, filed April 30, 2004; U.S. Provisional Application 60/604,549, filed August 25, 2004; U.S. Provisional Application 60/649,301, filed February 1, 2005; and PCT Publication WO 05/107924, published November 17, 2005. Each of these references is incorporated herein by reference.

Summary of the Disclosure The present disclosure concerns air cleaners and component features therefor. A variety of features and component features are described, for air cleaners and their components, including serviceable filter elements or filter cartridges. Selected features described herein relate to features providing for interaction between a filter element, a clean air outlet housing, and an air cleaner, facilitating installation of the filter element or filter cartridge therein.

It is noted that not all of the features described herein must be incorporated in an arrangement, for the arrangement to have some selected advantage according to the present disclosure.

Brief Description of the Drawings

Fig. 1 is a fragmentary, schematic, perspective view of z-filter media useable in arrangements according to the present disclosure. Fig. 2 is a schematic, cross-sectional view of a portion of the media depicted in Fig. 1.

Fig. 3 is a schematic view of examples of various corrugated media definitions. Fig. 3 A includes a schematic, fragmentary, cross-sectional view of a further fluted media configuration in a media pack comprising single facer strips.

Fig. 3B includes a schematic, fragmentary, cross-sectional view of a still further alternate fluted media configuration in a single facer media pack.

Fig. 3 C includes a schematic, fragmentary, cross-sectional view of yet another alternate fluted media configuration in a single facer media pack.

Fig. 4 is a schematic view of a useable process for manufacturing media according to the present disclosure.

Fig. 5 is a cross-sectional view of an optional end dart for media flutes useable in arrangements according to the present disclosure. Fig. 6 is a perspective view of an air cleaner assembly according to the present disclosure.

Fig. 7 is a perspective view of a filter element for use in the air cleaner assembly of Fig. 6.

Fig. 8 is a side, elevation view of the filter element of Fig. 7. Fig. 9 is an end elevation view of the filter element of Fig. 7.

Fig. 10 is a perspective view of the ring assembly of the filter element of Fig. 7.

Fig. 11 is a side view of the ring assembly of Fig. 10.

Fig. 12 is a perspective view of a filter assembly containing the filter element of Fig. 6 being introduced into an air cleaner outlet housing.

Fig. 13 is a side, elevation view of the filter assembly according to Fig. 12.

Fig. 14 is a side, elevation view of the filter assembly according to Fig. 13 where the filter element is fully inserted into the clean air outlet housing. Fig. 15 is a sectional view of the filter element and clean air outlet housing according to Fig. 14 taken along lines 15-15. Detailed Description of the Preferred Embodiment

I. Z-Filter Media Configurations, Generally.

Fluted filter media can be used to provide fluid filter constructions in a variety of manners. One well known manner is as a z-filter construction. The term "z-filter construction" as used herein, is meant to refer to a filter construction in which individual ones of corrugated, folded or otherwise formed filter flutes are used to define sets of longitudinal, filter flutes for fluid flow through the media; the fluid flowing along the length of the flutes between opposite inlet and outlet flow ends (or flow faces) of the media. Some examples of z-filter media are provided in U.S. patents 5,820,646; 5,772,883; 5,902,364; 5,792,247; 5,895,574; 6,210,469; 6,190,432; 6,350,296; 6,179,890; 6,235,195; Des. 399,944; Des. 428,128; Des. 396,098; Des. 398,046; and, Des. 437,401; each of these fifteen cited references being incorporated herein by reference.

One type of z-filter media, utilizes two specific media components joined together, to form the media construction. The two components are: (1) a fluted (typically corrugated) media sheet; and, (2) a facing media sheet. The facing media sheet is typically non-corrugated, however it can be corrugated, for example perpendicularly to the flute direction as described in U.S. provisional 60/543,804, filed February 11 , 2004, incorporated herein by reference.

The fluted (typically corrugated) media sheet and the facing media sheet, together, are used to define media having parallel inlet and outlet flutes. In some instances, the fluted sheet and non-fluted sheet are secured together and are then coiled to form a z-filter media construction. Such arrangements are described, for example, in U.S. 6,235,195 and 6,179,890, each of which is incorporated herein by reference. In certain other arrangements, some non-coiled sections of fluted media secured to flat media, are stacked on one another, to create a filter construction. An example of this is described in Fig. 11 of 5,820,646, incorporated herein by reference.

For specific examples described herein below, coiled arrangements are depicted, although many of the principles can be applied with stacked arrangements.

Typically, coiling of the fluted sheet/facing sheet combination around itself, to create a coiled media pack, is conducted with the facing sheet directed outwardly. Some techniques for coiling are described in U.S. provisional application 60/467,521, filed May 2, 2003 and PCT Application US 04/07927, filed March 17, 2004, each of which is incorporated herein by reference. The resulting coiled arrangement generally has, as the outer surface of the media pack, a portion of the facing sheet, as a result.

The term "corrugated" used herein to refer to structure in media, is meant to refer to a flute structure resulting from passing the media between two corrugation rollers, i.e., into a nip or bite between two rollers, each of which has surface features appropriate to cause a corrugation affect in the resulting media. The term "corrugation" is not meant to refer to flutes that are formed by techniques not involving passage of media into a bite between corrugation rollers. However, the term "corrugated" is meant to apply even if the media is further modified or deformed after corrugation, for example by the folding techniques described in PCT WO 04/007054, published January 22, 2004, incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media is media which has individual flutes (for example formed by corrugating or folding) extending thereacross.

Serviceable filter element or filter cartridge configurations utilizing z- filter media are sometimes referred to as "straight through flow configurations" or by variants thereof. In general, in this context what is meant is that the serviceable filter elements generally have an inlet flow end (or face) and an opposite exit flow end (or face), with flow entering and exiting the filter cartridge in generally the same straight through direction. (The term "straight through flow configuration" disregards, for this definition, air flow that passes out of the media pack through the outermost wrap of facing media.) The term "serviceable" in this context is meant to refer to a media containing filter cartridge that is periodically removed and replaced from a corresponding air cleaner. In some instances, each of the inlet flow end and outlet flow end will be generally flat or planar, with the two parallel to one another. However, variations from this, for example non-planar faces are possible.

A straight through flow configuration (especially for a coiled media pack) is, for example, in contrast to serviceable filter cartridges such as cylindrical pleated filter cartridges of the type shown in U.S. Patent No. 6,039,778, incorporated herein by reference, in which the flow generally makes a turn as its passes through the serviceable cartridge. That is, in a 6,039,778 filter, the flow enters the cylindrical filter cartridge through a cylindrical side, and then turns to exit through an end face (in forward-flow systems). In a typical reverse-flow system, the flow enters the serviceable cylindrical cartridge through an end face and then turns to exit through a side of the cylindrical filter cartridge. An example of such a reverse-flow system is shown in U.S. Patent No. 5,613,992, incorporated by reference herein. The term "z-fϊlter media construction" and variants thereof as used herein, without more, is meant to refer to any or all of: a web of corrugated or otherwise fluted media secured to (facing) media with appropriate sealing to inhibit air flow from one flow face to another without filtering passage through the filter media; and/or, such a media coiled or otherwise constructed or formed into a three dimensional network of flutes; and/or, a filter construction including such media. In many arrangements, the z-filter media constructions configured for the formation of a network of inlet and outlet flutes, inlet flutes being open at a region adjacent an inlet face and being closed at a region adjacent an outlet face; and, outlet flutes being closed adjacent an inlet face and being open adjacent an outlet face. However, alternative z-filter media arrangements are possible, see for example US 2006/0091084 Al, published May 4, 2006, incorporated herein by reference; also comprising flutes extending between opposite flow faces, with a seal arrangement to prevent flow of unfiltered air through the media pack. In Fig. 1 herein, an example of media 1 useable in z-filter media is shown. The media 1 is formed from a fluted (corrugated) sheet 3 and a facing sheet 4.

In general, the corrugated sheet 3, Fig. 1 is of a type generally characterized herein as having a regular, curved, wave pattern of flutes or corrugations 7. The term "wave pattern" in this context, is meant to refer to a flute or corrugated pattern of alternating troughs 7b and ridges 7a. The term "regular" in this context is meant to refer to the fact that the pairs of troughs and ridges (7b, 7a) alternate with generally the same repeating corrugation (or flute) shape and size. (Also, typically in a regular configuration each trough 7b is substantially an inverse of each ridge 7a.) The term "regular" is thus meant to indicate that the corrugation (or flute) pattern comprises troughs and ridges with each pair (comprising an adjacent trough and ridge) repeating, without substantial modification in size and shape of the corrugations along at least 70% of the length of the flutes. The term "substantial" in this context, refers to a modification resulting from a change in the process or form used to create the corrugated or fluted sheet, as opposed to minor variations from the fact that the media sheet 3 is flexible. With respect to the characterization of a repeating pattern, it is not meant that in any given filter construction, an equal number of ridges and troughs is necessarily present. The media 1 could be terminated, for example, between a pair comprising a ridge and a trough, or partially along a pair comprising a ridge and a trough. (For example, in Fig. 1 the media 1 depicted in fragmentary has eight complete ridges 7a and seven complete troughs 7b.) Also, the opposite flute ends (ends of the troughs and ridges) may vary from one another. Such variations in ends are disregarded in these definitions, unless specifically stated. That is, variations in the ends of flutes are intended to be covered by the above definitions.

In the context of the characterization of a "curved" wave pattern of corrugations, the term "curved" is meant to refer to a corrugation pattern that is not the result of a folded or creased shape provided to the media, but rather the apex 7a of each ridge and the bottom 7b of each trough is formed along a radiused curve. Although alternatives are possible, a typical radius for such z-filter media would be at least 0.25 mm and typically would be not more than 3 mm. (Media that is not curved, by the above definition, can also be useable.) An additional characteristic of the particular regular, curved, wave pattern depicted in Fig. 1, for the corrugated sheet 3, is that at approximately a midpoint 30 between each trough and each adjacent ridge, along most of the length of the flutes 7, is located a transition region where the curvature inverts. For example, viewing back side or face 3 a, Fig. 1 , trough 7b is a concave region, and ridge 7a is a convex region. Of course when viewed toward front side or face 3b, trough 7b of side 3 a forms a ridge; and, ridge 7a of face 3 a, forms a trough. (In some instances, region 30 can be a straight segment, instead of a point, with curvature inverting at ends of the segment 30.)

A characteristic of the particular regular, curved, wave pattern corrugated sheet 3 shown in Fig. 1 , is that the individual corrugations are generally straight. By "straight" in this context, it is meant that through at least 70% (typically at least 80%) of the length between edges 8 and 9, the ridges 7a and troughs 7b do not change substantially in cross-section. The term "straight" in reference to corrugation pattern shown in Fig. 1 , in part distinguishes the pattern from the tapered flutes of corrugated media described in Fig. 1 of WO 97/40918 and PCT Publication WO 03/47722, published June 12, 2003, incorporated herein by reference.. The tapered flutes of Fig. 1 of WO 97/40918, for example, would be a curved wave pattern, but not a "regular" pattern, or a pattern of straight flutes, as the terms are used herein. Referring to the present Fig. 1 and as referenced above, the media 1 has first and second opposite edges 8 and 9. When the media 1 is coiled and formed into a media pack, in general edge 9 will form an inlet end for the media pack and edge 8 an outlet end, although an opposite orientation is possible.

In the example shown, adjacent edge 8 is provided sealant, in this instance in the form of a sealant bead 10, sealing the corrugated (fluted) sheet 3 and the facing sheet 4 together. Bead 10 will sometimes be referred to as a "single facer" bead, since it is a bead between the corrugated sheet 3 and facing sheet 4, which forms the single facer or media strip 1. Sealant bead 10 seals closed individual flutes 11 adjacent edge 8, to passage of air therefrom.

In the example shown, adjacent edge 9, is provided sealant, in this instance in the form of a seal bead 14. Seal bead 14 generally closes flutes 15 to passage of unfiltered fluid therein, adjacent edge 9. Bead 14 would typically be applied as the media 1 is coiled about itself, with the corrugated sheet 3 directed to the inside. Thus, bead 14 will form a seal between a back side 17 of facing sheet 4, and side 18 of the corrugated sheet 3. The bead 14 will sometimes be referred to as a "winding bead" since it is typically applied, as the strip 1 is coiled into a coiled media pack. If the media 1 is cut in strips and stacked, instead of coiled, bead 14 would be a "stacking bead."

Referring to Fig. 1 , once the media 1 is incorporated into a media pack, for example by coiling or stacking, it can be operated as follows. First, air in the direction of arrows 12, would enter open flutes 11 adjacent end 9. Due to the closure at end 8, by bead 10, the air would pass through the media shown by arrows 13. It could then exit the media pack, by passage through open ends 15a of the flutes 15, adjacent end 8 of the media pack. Of course operation could be conducted with air flow in the opposite direction.

In more general terms, z-filter media comprises fluted filter media secured to facing filter media, and configured in a media pack of flutes extending between first and second opposite flow faces. A sealant arrangement is provided within the media pack, to ensure that air entering flutes at a first upstream edge cannot exit the media pack from a downstream edge, without filtering passage through the media. For the particular arrangement shown herein in Fig. 1 , the parallel corrugations 7a, 7b are generally straight completely across the media, from edge 8 to edge 9. Straight flutes or corrugations can be deformed or folded at selected locations, especially at ends. Modifications at flute ends for closure are generally disregarded in the above definitions of "regular," "curved" and "wave pattern." Z-filter constructions which do not utilize straight, regular curved wave pattern corrugation (flute) shapes are known. For example in Yamada et al. U.S. 5,562,825 corrugation patterns which utilize somewhat semicircular (in cross section) inlet flutes adjacent narrow V-shaped (with curved sides) exit flutes are shown (see Figs. 1 and 3, of 5,562,825). In Matsumoto, et al. U.S. 5,049,326 circular (in cross-section) or tubular flutes defined by one sheet having half tubes attached to another sheet having half tubes, with flat regions between the resulting parallel, straight, flutes are shown, see Fig. 2 of Matsumoto '326. In Ishii, et al. U.S. 4,925,561 (Fig. 1) flutes folded to have a rectangular cross section are shown, in which the flutes taper along their lengths. In WO 97/40918 (FIG. 1), flutes or parallel corrugations which have a curved, wave patterns (from adjacent curved convex and concave troughs) but which taper along their lengths (and thus are not straight) are shown. Also, in WO 97/40918 flutes which have curved wave patterns, but with different sized ridges and troughs, are shown.

In general, the filter media is a relatively flexible material, typically a non- woven fibrous material (of cellulose fibers, synthetic fibers or both) often including a resin therein, sometimes treated with additional materials. Thus, it can be conformed or configured into the various corrugated patterns, without unacceptable media damage. Also, it can be readily coiled or otherwise configured for use, again without unacceptable media damage. Of course, it must be of a nature such that it will maintain the required corrugated configuration, during use.

In the corrugation process, an inelastic deformation is caused to the media. This prevents the media from returning to its original shape. However, once the tension is released the flute or corrugations will tend to spring back, recovering only a portion of the stretch and bending that has occurred. The facing sheet is sometimes tacked to the fluted sheet, to inhibit this spring back in the corrugated sheet.

Also, typically, the media contains a resin. During the corrugation process, the media can be heated to above the glass transition point of the resin. When the resin then cools, it will help to maintain the fluted shapes.

The media of the corrugated sheet 3 facing sheet 4 or both, can be provided with a fine fiber material on one or both sides thereof, for example in accord with U.S. 6,673,136, incorporated herein by reference. An issue with respect to z-filter constructions relates to closing of the individual flute ends. Typically a sealant or adhesive is provided, to accomplish the closure. As is apparent from the discussion above, in typical z-filter media, especially that which uses straight flutes as opposed to tapered flutes, large sealant surface areas (and volume) at both the upstream end and the downstream end are needed. High quality seals at these locations are critical to proper operation of the media structure that results. The high sealant volume and area, creates issues with respect to this.

Still referring to Fig. 1 , at 20 tack beads are shown positioned between the corrugated sheet 3 and facing sheet 4, securing the two together. The tack beads can be for example, discontinuous lines of adhesive. The tack beads can also be points in which the media sheets are welded together.

From the above, it will be apparent that the corrugated sheet 3 is typically not secured continuously to the facing sheet, along the troughs or ridges where the two adjoin. Thus, air can flow between adjacent inlet flutes, and alternately between the adjacent outlet flutes, without passage through the media. However air which has entered in inlet flute cannot exit from an outlet flute, without passing through at least one sheet of media, with filtering. Attention is now directed to Fig. 2, in which a z-filter media construction 40 utilizing a fluted (in this instance regular, curved, wave pattern corrugated) sheet 43, and a non-corrugated flat, facing, sheet 44, is depicted. The distance Dl, between points 50 and 51, defines the extension of flat media 44 in region 52 underneath a given corrugated flute 53. The length D2 of the arcuate media for the corrugated flute 53, over the same distance Dl is of course larger than Dl, due to the shape of the corrugated flute 53. For a typical regular shaped media used in fluted filter applications, the linear length D2 of the media 53 between points 50 and 51 will generally be at least 1.2 times Dl . Typically, D2 would be within a range of 1.2 - 2.0, inclusive. One particularly convenient arrangement for air filters has a configuration in which D2 is about 1.25 - 1.35 x Dl . Such media has, for example, been used commercially in Donaldson Powercore™ Z-filter arrangements. Herein the ratio D2/D1 will sometimes be characterized as the flute/flat ratio or media draw for the corrugated media.

In the corrugated cardboard industry, various standard flutes have been defined. For example the standard E flute, standard X flute, standard B flute, standard C flute and standard A flute. Figure 3, attached, in combination with Table A below provides definitions of these flutes.

Donaldson Company, Inc., (DCI) the assignee of the present disclosure, has used variations of the standard A and standard B flutes, in a variety of z-filter arrangements. These flutes are also defined in Table A and Fig. 3.

TABLE A

(Flute definitions for Fig. 3)

DCI A Flute: Flute/flat = 1.52: 1 ; The Radii (R) are as follows:

Rl 000 = .0675 inch (1.715 mm); Rl 001 = .0581 inch (1.476 mm); R1002 = .0575 inch (1.461 mm); R1003 = .0681 inch (1.730 mm);

DCI B Flute: Flute/flat = 1.32:1; The Radii (R) are as follows:

R1004 = .0600 inch (1.524 mm); R1005 = .0520 inch (1.321 mm); R1006 = .0500 inch (1.270 mm); R1007 = .0620 inch (1.575 mm);

Std. E Flute: Flute/flat = 1.24: 1 ; The Radii (R) are as follows:

Rl 008 = .0200 inch (.508 mm); Rl 009 = .0300 inch (.762 mm); RlOlO = .0100 inch (.254 mm); RlOl 1 = .0400 inch (1.016 mm);

Std. X Flute: Flute/flat = 1.29: 1 ; The Radii (R) are as follows:

R1012 = .0250 inch (.635 mm); R1013 = .0150 inch (.381 mm);

Std. B Flute: Flute/flat = 1.29: 1 ; The Radii (R) are as follows:

R1014 = .0410 inch (1.041 mm); R1015 = .0310 inch (.7874 mm); R1016 = .0310 inch (.7874 mm);

Std. C Flute: Flute/flat = 1.46: 1 ; The Radii (R) are as follows:

R1017 = .0720 inch (1.829 mm); R1018 = .0620 inch (1.575 mm);

Std. A Flute: Flute/flat = 1.53:1; The Radii (R) are as follows:

Rl019 = .0720 inch (1.829 mm); Rl020 = .0620 inch (1.575 mm).

Of course other, standard, flutes definitions from the corrugated box industry are known.

In general, standard flute configurations from the corrugated box industry can be used to define corrugation shapes or approximate corrugation shapes for corrugated media. Comparisons above between the DCI A flute and DCI B flute, and the corrugation industry standard A and standard B flutes, indicate some convenient variations.

It is noted that alternative flute definitions such as those characterized in USSN 12/215,718, filed June 26, 2008; and 12/012,785, filed February 4, 2008 can be used, with air cleaner features as characterized herein below. The complete disclosures of each of USSN 12/215,718 and 12/012,785 are incorporated herein by reference.

In Figs. 3A-3C, cross-sectional views of exemplary portions of filtration media are shown wherein the fluted sheet has one or more non-peak ridge extending along at least a portion of the flute length. Fig. 3 A shows a fluted sheet having one non-peak ridge provided between adjacent peaks, and Figs. 3B and 3C show fluted sheets having two non-peak ridges between adjacent peaks. The non- peak ridges can extend along the flute length any amount including, for example, an amount of 20% of the flute length to 100% of the flute length. In addition, the fluted sheet can be provided without non-peak ridges between all adjacent peaks, and can be provided with differing numbers of non-peak ridges between adjacent peaks (e.g., alternating zero, one, or two non-peak ridges in any arrangement). The presence of non-peak ridges can help provide more media available for filtration in a given volume, and can help reduce stress on the fluted sheet thereby allowing for a smaller radius at the peaks and therefore reduced media masking. Such media can be used in arrangements according to the present disclosure.

II. Manufacture of Coiled Media Configurations Using Fluted Media,

Generally.

In Fig. 4, one example of a manufacturing process for making a media strip corresponding to strip 1 , Fig. 1 is shown. In general, facing sheet 64 and the fluted (corrugated) sheet 66 having flutes 68 are brought together to form a media web 69, with an adhesive bead located therebetween at 70. The adhesive bead 70 will form a single facer bead 10, Fig. 1. An optional darting process occurs at station 71 to form center darted section 72 located mid- web. The z-filter media or Z-media strip 74 can be cut or slit at 75 along the bead 70 to create two pieces 76, 77 of z-filter media 74, each of which has an edge with a strip of sealant (single facer bead) extending between the corrugating and facing sheet. Of course, if the optional darting process is used, the edge with a strip of sealant (single facer bead) would also have a set of flutes darted at this location.

Techniques for conducting a process as characterized with respect to Fig. 4 are described in PCT WO 04/007054, published January 22, 2004 incorporated herein by reference.

Still in reference to Fig. 4, before the z-filter media 74 is put through the darting station 71 and eventually slit at 75, it must be formed. In the schematic shown in Fig. 4, this is done by passing a sheet of media 92 through a pair of corrugation rollers 94, 95. In the schematic shown in Fig. 4, the sheet of media 92 is unrolled from a roll 96, wound around tension rollers 98, and then passed through a nip or bite 102 between the corrugation rollers 94, 95. The corrugation rollers 94, 95 have teeth 104 that will give the general desired shape of the corrugations after the flat sheet 92 passes through the nip 102. After passing through the nip 102, the sheet 92 becomes corrugated across the machine direction and is referenced at 66 as the corrugated sheet. The corrugated sheet 66 is then secured to facing sheet 64. (The corrugation process may involve heating the media, in some instances.)

Still in reference to Fig. 4, the process also shows the facing sheet 64 being routed to the darting process station 71. The facing sheet 64 is depicted as being stored on a roll 106 and then directed to the corrugated sheet 66 to form the Z- media 74. The corrugated sheet 66 and the facing sheet 64 would typically be secured together by adhesive or by other means (for example by sonic welding). Referring to Fig. 4, an adhesive line 70 is shown used, to secure corrugated sheet 66 and facing sheet 64 together, as the sealant bead. Alternatively, the sealant bead for forming the facing bead could be applied as shown as 70a. If the sealant is applied at 70a, it may be desirable to put a gap in the corrugation roller 95, and possibly in both corrugation rollers 94, 95, to accommodate the bead 70a. Of course the equipment of Fig. 4 can be modified to provide for the tack beads 20, if desired.

The type of corrugation provided to the corrugated media is a matter of choice, and will be dictated by the corrugation or corrugation teeth of the corrugation rollers 94, 95. One useful corrugation pattern will be a regular curved wave pattern corrugation, of straight flutes, as defined herein above. A typical regular curved wave pattern used, would be one in which the distance D2, as defined above, in a corrugated pattern is at least 1.2 times the distance Dl as defined above. In example applications, typically D2 = 1.25 - 1.35 x Dl, although alternatives are possible. In some instances the techniques may be applied with curved wave patterns that are not "regular," including, for example, ones that do not use straight flutes. Also, variations from the curved wave patterns shown, are possible.

As described, the process shown in Fig. 4 can be used to create the center darted section 72. Fig. 5 shows, in cross-section, one of the flutes 68 after darting and slitting.

A fold arrangement 118 can be seen to form a darted flute 120 with four creases 121a, 121b, 121c, 121 d. The fold arrangement 118 includes a flat first layer or portion 122 that is secured to the facing sheet 64. A second layer or portion 124 is shown pressed against the first layer or portion 122. The second layer or portion 124 is preferably formed from folding opposite outer ends 126, 127 of the first layer or portion 122. Still referring to Fig. 5, two of the folds or creases 121a, 121b will generally be referred to herein as "upper, inwardly directed" folds or creases. The term "upper" in this context is meant to indicate that the creases lie on an upper portion of the entire fold 120, when the fold 120 is viewed in the orientation of Fig. 5. The term "inwardly directed" is meant to refer to the fact that the fold line or crease line of each crease 121a, 121b, is directed toward the other.

In Fig. 5, creases 121c, 121d, will generally be referred to herein as "lower, outwardly directed" creases. The term "lower" in this context refers to the fact that the creases 121c, 121d are not located on the top as are creases 121a, 121b, in the orientation of Fig. 5. The term "outwardly directed" is meant to indicate that the fold lines of the creases 121c, 121d are directed away from one another.

The terms "upper" and "lower" as used in this context are meant specifically to refer to the fold 120, when viewed from the orientation of Fig. 5. That is, they are not meant to be otherwise indicative of direction when the fold 120 is oriented in an actual product for use.

Based upon these characterizations and review of Fig. 5, it can be seen that a preferred regular fold arrangement 118 according to Fig. 5 in this disclosure is one which includes at least two "upper, inwardly directed, creases." These inwardly directed creases are unique and help provide an overall arrangement in which the folding does not cause a significant encroachment on adjacent flutes.

A third layer or portion 128 can also be seen pressed against the second layer or portion 124. The third layer or portion 128 is formed by folding from opposite inner ends 130, 131 of the third layer 128. Another way of viewing the fold arrangement 118 is in reference to the geometry of alternating ridges and troughs of the corrugated sheet 66. The first layer or portion 122 is formed from an inverted ridge. The second layer or portion 124 corresponds to a double peak (after inverting the ridge) that is folded toward, and in preferred arrangements, folded against the inverted ridge. Techniques for providing the optional dart described in connection with Fig. 5, in a preferred manner, are described in PCT WO 04/007054, incorporated herein by reference. Techniques for coiling the media, with application of the winding bead, are described in PCT application US 04/07927, filed March 17, 2004 and incorporated herein by reference. Techniques described herein are particularly well adapted for use in media packs that result from coiling a single sheet comprising a corrugated sheet/facing sheet combination, i.e., a "single facer" strip. Certain of the techniques can be applied with arrangements that, instead of being formed by coiling, are formed from a plurality of strips of single facer. Coiled media pack arrangements can be provided with a variety of peripheral perimeter definitions. In this context the term "peripheral, perimeter definition" and variants thereof, is meant to refer to the outside perimeter shape defined, looking at either the inlet end or the outlet end of the media pack. Typical shapes are circular as described in PCT WO 04/007054 and PCT application US 04/07927. Other useable shapes are obround, some examples of obround being oval shape. In general oval shapes have opposite curved ends attached by a pair of opposite sides. In some oval shapes, the opposite sides are also curved. In other oval shapes, sometimes called racetrack shapes, the opposite sides are generally straight. Racetrack shapes are described for example in PCT WO 04/007054 and

PCT application US 04/07927.

Another way of describing the peripheral or perimeter shape is by defining the perimeter resulting from taking a cross-section through the media pack in a direction orthogonal to the winding access of the coil.

Opposite flow ends or flow faces of the media pack can be provided with a variety of different definitions. In many arrangements, the ends are generally flat and perpendicular to one another. In other arrangements, the end faces include tapered, coiled, stepped portions which can either be defined to project axially outwardly from an axial end of the side wall of the media pack; or, to project axially inwardly from an end of the side wall of the media pack.

The flute seals (for example from the single facer bead, winding bead or stacking bead) can be formed from a variety of materials. In various ones of the cited and incorporated references, hot melt or polyurethane seals are described as possible for various applications.

III. Air Cleaner Arrangement Utilizing Z-Filter Media.

Now referring Fig. 6, an air cleaner is shown at reference number 200. The air cleaner 200 includes an air inlet region 202, an air filtration region 204, and a clean air outlet region 206. hi general, unfiltered air flows in through the air inlet region 202, is cleaned in the air filtration region 204, and exits through the clean air outlet region 206.

The air inlet region 202 can include as a housing 208 mounted to a motor vehicle, such as, a truck or tractor, and having an air inlet 207 and an air outlet 209. Within the housing 208 or upstream of the housing 208 can be provided precleaners and/or water separation devices that can be used to remove relatively large particulates and water from the unfiltered air flowing therethrough. Precleaners and water separation devices that are commonly used in air filtration equipment for motor vehicles such as trucks and tractors can be used. The clean air outlet region 206 generally include duct work 210 that conveys cleaned air to where it is consumed, for example, by an internal combustion engine. The duct work 210 includes a clean air inlet 211 that receives clean air from the air filtration region 204 and a clean air outlet 213. The clean air outlet 213 can include flexible duct work 215 that allows movement of the clean air outlet region 206 away from the air filtration region 204 when the clean air outlet region 206 and the air filtration region 204 are disconnected.

The air inlet region 202 and the clean air outlet region 206 are provided so that they can be relatively easily attached to and detached from the air filtration region 204. As shown in Fig. 6, fasteners 212 can be used to hold the clean air outlet region 206 to the air filtration region 204 and to hold the air inlet region 202 to the air filtration region 204. Exemplary fasteners 212 that can be used include non-compressive fasteners 214. Exemplary non-compressive 214 include bale fasteners. Bale fasteners are a type of fastener commonly used for attaching duct work together where compressive forces are not required. An advantage of using non-compressive fastener 214 is the ability to relatively easily remove the air filtration region 204 from the air cleaner 200 for servicing, and then reintroduce the air filtration region 204 into the air cleaner 200. As shown in Fig. 6, the clean air outlet bales 216 can be provided for attaching the air filtration region 204 to the clean air outlet region 206. The clean air outlet bales 216 can be provided extending from supports 218 on the air filtration region 204 and can engage ears 220 on the duct work 210. Alternatively, the arrangement of the bales can be reversed so that the bales extend from supports on the duct work and the ears are placed on the air filtration region 204. Similarly, air inlet bales 222 can be provided for holding the housing 208 to the air filtration region 204. The air inlet bales 222 can be provided extending from the supports 218 on the housing 208 and can engage the ears 220 on the air filtration region 204. If desired, the arrangement of the supports 218 and the ears 220 can be reversed. Although over center latches can be used in place of the bales, an advantage of the bales is the ability to provide the connection without the need for compressive forces associated with the use of over center latches. The operator using the bales can understand that the components need to be aligned properly in order for the bale to fit and provide a snug connection. Over center latches may cause a technician to force a connection.

The air filtration region 204 includes a filter element or filter cartridge 230 and a clean air outlet housing 232. The combination of the filter element 230 and the clean air outlet housing 232 can be referred to as the filter element and clean air outlet housing assembly 234. In general, the filter element or filter cartridge 230 is serviceable. That means it can be discarded and replaced with a new filter element or filter cartridge during servicing. An advantage of the air cleaner 200 is that the filter element and clean air outlet housing assembly 234 can be removed from air cleaner 200, and the filter element 230 can then be replaced as a component of the filter element and clean air outlet housing assembly 234 at a location away from the motor vehicle. For example, the fasteners 212 can be released so that the filter element and clean air outlet housing assembly 234 can be separated from the air inlet region 202 and the clean air outlet region 206 of the air cleaner 200. Once the filter element and clean air outlet housing assembly 234 is removed from the air cleaner 200, the technician servicing the motor vehicle can remove the filter element 230 from the clean air outlet housing 232. The technician can then introduce a new or cleaned filter element 230 into the clean outlet housing 232. Because the filter element and clean air outlet housing assembly 234 can be separated from the motor vehicle, the technician servicing the air cleaner can deal with replacement of the air filter 230 on a bench or table where it is convenient to apply compressive forces in order to remove an old filter element and introduce a new or cleaned filter element. As will be explained in more detail, a new or cleaned filter element can be placed on a level surface such as a table top, and the clean air outlet housing can be applied over the filter element so that the filter element and the clean air outlet housing are properly aligned and engaged with one another. Once the seal between the filter element 230 and the clean air outlet housing 232 is established, the resulting filter element and clean air outlet housing assembly 234 can be reintroduced as part of the air cleaner 202. By providing the ability to implement the changing a filter element (e.g., aligning the filter element correctly with the clean air outlet housing and introducing the requisite amount of compressive force to provide a seal) at a location such as a bench top or table top location rather than on a motor vehicle, the procedure for servicing air cleaner of a motor vehicle can be standardized, and reliability can be enhanced. Furthermore, forces applied to the air inlet region 202 and the air outlet region 206 can be minimized.

Now referring to Figs. 7-11, the filter element 230 can be referred to as a primary air filter cartridge which is serviceable, removable, and replaceable. After a certain period of use or once the pressure drop through the filter element reaches a certain level, the filter element can be removed and a new filter element can be provided in its place. Alternatively, a cleaned filter element can be provided in its place. The filter element 230 includes a media pack 240, a seal arrangement 250, a ring member 260, and a fastening system 270.

The media pack 240 includes an inlet face 242 and an outlet face 244. During use, unfiltered air enters the media pack 240 through the inlet face 242, and filtered air exits the media pack 240 through the outlet face 244. The media pack 240 can be characterized as generally closed to flow of air therethrough, between the inlet face 242 and the outlet face 244 unless the air passes through a media sheet (fluted or facing) with filtering.

The media pack 240 generally comprises z-filter media in accord with the descriptions provided above. As explained above, z-filter media can be provided in any of two forms: as a coiled arrangement of a single facer comprising a fluted (e.g., corrugated) media sheet secured to a facing media sheet; or, as a stack of strips of single facer each of comprising a fluted (e.g.,corrugated) media sheet secured to a facing media sheet. Either type of arrangement can be provided with the general techniques described herein. However, the assembly depicted is specifically configured for use with coiled arrangements, and variations in shapes and other detail would typically be used when a stack media pack arrangement is to be used. Thus, the example media pack 240 depicted comprises a coiled z-filter media arrangement, comprising a fluted (corrugated) media sheet secured to a facing media sheet, coiled with a facing sheet directed outwardly. The exterior of the media pack 240 is shown, in Fig. 7, as a facing media sheet 241. The exterior of the media pack, however, can be provided as another material such as an impermeable sheet or film, if desired.

The coiled media pack 240 has a generally obround perimeter (peripheral) shape, particularly an oval perimeter shape comprising two opposite curved ends 246a and 246b, with sides 246c and 246d extending therebetween. The shape can be characterized as racetrack when the sides 246c and 246d are approximately straight and parallel to one another.

The seal arrangement 250 is depicted mounted at an end of the media pack 240 at the outlet face 244. In alternative embodiments, the placement of the seal arrangement can be varied. For example, the seal arrangement can be provided circumferentially around media pack at a location between the end faces 242 and 244. The seal arrangement 250 includes a seal member 252 having a seal surface 254 that is constructed for engaging a housing seal surface 236 on the clean air outlet housing 232 (see Fig. 15). The seal member 252 is depicted as a radially directed seal 256 that can be referred to a radial seal because the forces of the seal member 252 are primarily directed radially. If desired, the seal member can be provided as an axially directed seal (e.g., an axial seal) or as a combination of an axial seal and a radial seal. An exemplary type of axial seal that can be used includes an axial pinch seal. The particular seal member 252, depicted and positioned as configured, forms an outwardly directed radial seal, compressed upon the housing seal surface 236 of the clean air outlet housing 232. A variety of types of housing seal arrangements are possible, selected ones of which are described in U.S. Patents 6,783,565, 6,190,432, 6,350,291, 6,610,117, U.S. Publication US 2005/0166561, published August 4, 2005, PCT Publication WO 05/63361 and U.S. Provisional Application 60/735,650, filed November 9, 2005, incorporated herein by reference. Some examples of such seal arrangements are discussed briefly below. Typically, the seal member 252 comprises a compressible polymeric material, for example foamed polyurethane, supported by frame structure 257, against which the polymeric material can compress, when inserted so that it engages the housing seal surface 236 (Fig. 15).

For the radial seal configuration shown, the seal surface 254 can be positioned at a location axially beyond the end face 244 of the media pack 240, in a direction opposite the end face 242. That is, the seal surface 254, which sealingly engages the housing seal surface 236, can be provided so that it does not extend around the media pack 240 but rather is mounted on a frame structure 257 projecting axially outward from the media pack 240, away from the media pack 240 in a direction opposite the end face 242. For the example shown, the seal surface 254 is part of a seal member 252 which can be characterized as an overmould 258 which has a second, but integral, attachment portion 259 that does engage and surround the media pack 240. The frame structure 257 can be provided extending away from the outlet face 244, and the overmold 258 can be applied over the frame structure 257 and the circumferential side of the media pack 249 that is adjacent the outlet flow face 244. The overmold 258 can form the seal member 252 that is supported by the frame structure 257, and can form the attachment portion 259 that attaches the seal arrangement 250 to the media pack 240 at the circumferential side of the media pack 249. The frame structure 257 includes a first arm 290 and a second arm

292. The first arm 290 can be provided as a step or circumference reducer that allows the second arm 292 to exhibit to circumference that is less than the exterior circumference of the media pack 240. The second arm 292 can then support the seal member 252. An advantage of providing a reduction in circumference for a seal arrangement 250 extending beyond the end face 244 the media pack 240 is the ability to fit the media pack 240 into a size constrained clean air outlet housing 232. In an alternative embodiment where the clean air outlet housing can have a greater circumference, it is possible to avoid the use of a first arm 290 having a circumference reducing effect. Furthermore, the frame structure 257 can include a brace or cross brace structure 296. The brace or cross brace structure 296 can be provided extending across the media pack end face 244 to support the frame structure 257 and to reduce the possibility of the media pack 240 deforming.

The ring member 260 can be provided as a preform 262 that fits to the media pack 240 near the inlet flow faces 242. The ring member 260 can include a side structure 264 and an end structure 266. The side structure 264 can include a lip 268 that can be constructed to engage the exterior of the media pack 240. Furthermore, the side structure 264 can include a skirt 269 that is capable of supporting the fastening system 270. The end structure 266 can be provided so that it extends across the media pack flow face 242 and supports the media pack 240. The end structure 266 can include a support structure or cross brace structure 267 that helps support the media pack 240 and reduces the possibility of the media pack deforming. The ring member 260 can be attached to the media pack 240 adjacent the inlet flow face 242 by placing the media pack 240 within the perform 262 so that the lip 268 engages and adheres to the exterior of the media pack near the inlet flow face 242. Adhesive can be use to adhere the lip 268 to the media pack 240 along the media pack exterior.

The end structure 266 can be provided having an exterior surface that extends across the inlet flow face 242 of the media pack 240 and allows the filter element 230 to rest on a relatively flat surface. The filter element 230 can be provided so that it can be placed on a relatively flat surface in the orientation shown in Fig. 7.

The fastening system 270 of the filter element 230 includes a first filter element fastener 272 and a second filter element fastener 274. The first filter element fastener 272 and the second filter element fastener 274 can be provided as essentially identical fasteners but provided on opposite sides of the ring member 260 and extending from the skirt 269. The ring member 260 can be provided having a configuration that generally corresponds to the shape of the filter element 230, and can be characterized as having ends 260a and 260b, and sides 260c and 26Od. The first filter element fastener 272 and the second filter element fastener 274 can be provided having a ring attachment area 276, an extension 277, and a fastener element 278. The ring attachment area 276 is provided for attachment to the ring member 260. The extension 277 is provided so that the fastener system 270 has the correct length that provides for the filter element 230 with a secure and reliable sealing engagement with the clean air outlet housing 232. The fastener element 278 is provided for engaging a mating fastener 310 on the clean air outlet housing 232. The fastener element 278 can be provided as a relatively flexible fastener element 279, and the mating fastener 310 can be provided as a relatively non-flexible fastener element 312. The reference to "relatively flexible" and "relatively non- flexible" refers to the flex provided when the fasteners engage each other. The relatively flexible fastener 279 is intended to flex when it engages the relatively non- flexible fastener element 312. In an alternative arrangement, the relatively flexible fastener element can be provided extending from the clean air outlet housing 232, and the relatively non-flexible fastener element can be provided extending from the filter element 230. However, by having the flexible fastener element 279 on the replaceable filter element 230, there is less likelihood that the flexible fastener element will wear out. For example, if the flexible fastener element were placed on the clean air outlet housing 232, there is a chance that after multiple servicing or changing of the filter element 230 that the flexible fastener element may wear out. By providing the flexible fastener element on the filter element 230, it is likely that the filter element 230 will be discarded well before there is any wear issue relating to the flexible fastener element.

An advantage of using a combination of a relatively flexible fastener 279 and a relatively non-flexible fastener element 312 is that when they are fully engaged (as shown in Fig. 14), there is an audible click sound that can help tell the technician servicing the air cleaner that the filter element 230 is fully inserted within the clean air housing 232. Accordingly, once the technician hears the click sound and visually confirm that the fasteners on both sides of the filter element are fully engaged, the technician can feel confident that the filter element 230 and the clean air outlet housing 232 are fully attached together. The fastening element 278 and the mating fastener 310 can be provided as snap fasteners that snap together and can be disconnected by comprising the fastening element 278 and pulling the fastening element 278 and the mating fastener 310 apart.

Now referring to Figs. 12-15, the clean air outlet housing 232 is shown in relationship to the filter element 230. The clean air outlet housing 232 includes a housing member 300 extending from a filter element receiving area 302 to a clean air outlet 304. In general, the housing member 300 provides for the conveyance of clean air from the filter element receiving area 302 to the clean air outlet 304. The clean air outlet 304 is constructed for attachment to the clean air inlet 211 of the air outlet region 206.

The filter element receiving area 302 is constructed to receive the filter element 230 and sealingly engage with the seal member 252. The filter element receiving area 302 includes a lip 306 that fits over the exterior of the filter element 240, and includes a housing seal surface 236 that engages the seal surface 254 on the seal member 252 to provide a seal preventing the flow of unfiltered air into the interior region 308 provided within the clean air outlet housing 232. The sealing engagement of the filter element 230 and the clean air housing 232 is shown in the context of Figs. 12-14. For example, in Fig. 12, the filter element 230 can be arranged so that the end structure 266 is provided on a relatively flat surface such as a bench or table. The clean air outlet housing 232 can be arranged over the filter element 230 so that the filter element receiving area 302 covers the filter element end face 244. As the clean air outlet housing 232 is pressed downwardly over the filter element 230, the seal member 252 engages the housing seal surface 236 so that the seal surface 254 and the housing seal surface 236 create a seal. In Fig. 13, the arrows 320 show an exemplary direction of force applied to the clean air outlet housing 232 downward onto the filter element 230. As the clean air outlet housing 232 is applied over the filter element 230, the filter element fasteners 272 engage the mating fasteners 310. Once the filter element fasteners and the mating fasteners are engaged and locked together, the seal surface 254 and the housing seal surface 236 are in a sealing relationship as shown in Fig. 15. The resulting filter element 230 and the clean air outlet housing 232 can then be introduced into the air cleaner 200.

A variety of features are described. Variations in them are possible; and, there is no requirement that an arrangement include all the features describe to have some advantage.

Claims

WE CLAIM:

1. A filter element comprising:

(a) a media pack having an inlet flow face and an opposite outlet flow face; (i) the media pack comprising a plurality of flutes extending between the inlet flow face and the outlet flow face; and (ii) the media pack being closed to passage of unfiltered air therethrough, between the inlet flow face and the outlet flow face;

(b) a seal member constructed to provide a seal between the media pack and a clean air outlet housing;

(c) a ring member positioned on the media pack and including a first side and an opposite second side; and

(d) a first fastener attached to the first side of the ring member, and a second fastener attached to the second side of the ring member; the first fastener and the second fastener are constructed to engage a first mating fastener and a second mating fastener on a clean air outlet housing having a seal surface and constructed to receive the seal member so that when the first and second fasteners engage the first and second mating fasteners, the filter element is fully received within the clean air outlet housing and is held in place.

2. A filter element according to claim 1 , wherein the seal member comprises a radial seal having a radially directed sealing surface.

3. A filter element according to claim 2, wherein the radially directed sealing surface is provided downstream of the media pack outlet flow face.

4. A filter element according to claim 2, wherein the radially directed sealing surface is supported by a frame structure projecting axially away from the media pack.

5. A filter element according to claim 4, wherein the frame structure comprises a brace structure extending across the media pack outlet flow face.

6. A filter element according to claim 4, wherein the frame structure comprises a first arm for supporting the seal member and a second arm for reducing the radius of the first arm.

7. A filter element according to claim 1 , wherein the seal member comprises an overmold seal having an attachment portion that attaches to the media pack and that is intergral with the seal member.

8. A filter element according to claim 1 , wherein the ring member is positioned on the media pack adjacent the inlet flow face and circumscribing the media pack at the media flow face.

9. A filter element according to claim 8, wherein the ring member comprises a support structure extending from the first side to the opposite second side of the ring member, and supporting the media pack inlet flow face.

10. A filter element according to claim 1, wherein the first fastener and the second fastener each comprise a relatively flexible fastener element constructed to engage a relatively non-flexible fastener element so that when the relatively flexible fastener element engages the relatively non-flexible fastener element a click sound can be heard.

11. A filter element and clean air outlet housing assembly comprising:

(a) a clean air outlet housing comprising a filter element receiving area structured to receive a filter element and having a housing seal surface, and comprising a first mating fastener and a second mating fastener; and

(b) a filter element constructed for receipt within the filter element receiving area of the clean air outlet housing; the filter element comprising:

(1) a media pack having an inlet flow face and an opposite outlet flow face;

(i) the media pack comprising a plurality of flutes extending between the inlet flow face and the outlet flow face; and (ii) the media pack being closed to passage of unfiltered air therethrough, between the inlet flow face and the outlet flow face;

(2) a seal member comprising a sealing surface constructed to sealingly engage the housing seal surface;

(3) a ring member positioned on the media pack and including a first side and an opposite second side; and

(4) a first fastener attached to the first side of the ring member, and a second fastener attached to the second side of the ring member; the first fastener and the second fastener are constructed to engage the first mating fastener and the second mating fastener on a clean air outlet housing so that when the first and second fasteners engage the first and second mating fasteners, the filter element is fully received within the clean air outlet housing and is held in place.

12. A filter element and clean air outlet housing according to claim 11 , wherein the seal member comprises a radial seal having a radially directed sealing surface.

13. A filter element and clean air outlet housing according to claim 12, wherein the radially directed sealing surface is provided downstream of the media pack outlet flow face.

14. A filter element and clean air outlet housing according to claim 12, wherein the radially directed sealing surface is supported by a frame structure projecting axially away from the media pack.

15. A filter element and clean air outlet housing according to claim 14, wherein the frame structure comprises a brace structure extending across the media pack outlet flow face.

16. A filter element and clean air outlet housing according to claim 14, wherein the frame structure comprises a first arm for supporting the seal member and a second arm for reducing the radius of the first arm.

17. A filter element and clean air outlet housing according to claim 11 , wherein the seal member comprises an overmold seal having an attachment portion that attaches to the media pack and that is intergral with the seal member.

18. A filter element and clean air outlet housing according to claim 11, wherein the ring member is positioned on the media pack adjacent the inlet flow face and circumscribing the media pack at the media flow face.

19. A filter element and clean air outlet housing according to claim 18, wherein the ring member comprises a support structure extending from the first side to the opposite second side of the ring member, and supporting the media pack inlet flow face.

20. A filter element and clean air outlet housing according to claim 11 , wherein the first fastener and the second fastener each comprise a relatively flexible fastener element and the first mating fastener and the second mating faster each comprise a relatively non-flexible fastener element so that when the relatively flexible fastener element engages the relatively non-flexible fastener element a click sound can be heard.