BRPI0507946B1 - Air filter cartridge, and method for making such a cartridge - Google Patents

Description

"AIR FILTER CARTRIDGE, AND METHOD FOR MAKING SUCH CARTRIDGE" This application claims priority under 35 U.S.C. § 119 (e) for provisional patent application no. 60 / 556,113, filed March 24, 2004. Full disclosure of application no. No. 60 / 556,113 is incorporated herein by reference.

TECHNICAL FIELD The present disclosure relates to filter constructs for filtering fluids such as liquids or gases. This particular disclosure relates to: direct flow filter cartridges; safety filters, assemblies employing such filters, prefilters, and methods for using and assembling filter cartridges.

BACKGROUND OF THE INVENTION

Direct flow filters (filter elements or filter cartridges) have been used in various systems to filter fluids such as gases or liquids. Direct flow filters typically have an inlet face (or end) and an opposite arranged outlet face (or end). During filtration, the fluid to be filtered passes in one direction as it enters the filter at the inlet face, and has the same general flow direction as it leaves the outlet face. Typically, a direct flow filter is installed in a housing for use. After a period of sweat, the filter requires maintenance, either by cleaning or completely replacing the filter. A seal is required between the filter and a portion of the housing in which the filter is put into use to ensure proper filtration of fluid passing through the arrangement.

Improvements in direct flow filters, their assemblies and their uses are desirable.

SUMMARY

According to the present disclosure, a filter element or cartridge is provided. The filter element or cartridge in general has a direct flow construction and comprises z-filter means. The filter element or cartridge includes a sealing gasket.

A particular type of air filter cartridge relates to the present disclosure. In general, the air filter cartridge comprises: a z-filter media package; a preform having a part circumscribing the media pack, the preform including a sealing support portion of the housing; and a housing sealing arrangement. The housing sealing arrangement generally includes: a housing sealing portion secured to the housing sealing bracket and a sealing portion of the media package that circumscribes the media package and seals the preform in the media package. Preferably, the sealing portion of the media pack is (molded) integral with the sealing portion of the housing. Also, preferably, the sealing support portion of the housing includes a plurality of openings therethrough; and the housing sealing arrangement includes a sealing material extending through the sealing openings to mechanically secure the sealing material to the preform.

In a particular form of currently disclosed techniques, the coiled z-filter media package is positioned within a preform. The preform includes an outer sidewall shell, an end grid in a core secured to the end grid and projecting internally within the path of the z-filter media pack. Construction of this arrangement involves inserting the coiled media pack into the preform, causing the core to be pushed into the media pack. As indicated, the core does not project completely through the media pack, but instead typically and preferably no more than 75% across the axial length of the media pack, usually no more than 60%. One end of the media pack opposite the end at which the core projects, preferably the media pack has no central core. Preferred attachment of the media pack to the preform would be as previously characterized. Methods of preparation of such filter cartridges are provided.

The features, techniques, and principles revealed can be applied to a variety of filter cartridges for a variety of uses. In the drawings, a system using a preferred filter cartridge according to the principles previously generally characterized according to the principles in the PCT application of April 3, 2003 (PCT / US03 / 10258) which claims priority for US 60 / 370,438, filed April 4, 2002, 60 / 426,071, filed November 12, 2003 and 10 / 405,432, filed April 2, 2003, the full disclosures of which are hereby incorporated by reference.

Here, a variety of features, arrangements and techniques are provided that can be incorporated into air filter arrangements to advantage. Selected techniques, resources and arrangements can be used to your advantage. Together, a particularly preferred arrangement is provided. However, it is not a requirement that all filter elements or assemblies must incorporate all advantageous features herein to obtain the benefit and advantage in accordance with the present disclosure. Individual resources, techniques and advantages can be selected and selectively combined for various alternative arrangements.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side perspective view of an air filter arrangement in accordance with the present disclosure; Figure 2 is an exploded perspective view of the air filter arrangement shown in Figure 1, the prefilter, primary filter and safety filter being visible; Figure 2a is an exploded perspective view of a portion of the air filter arrangement prefilter assembly shown in Figure 1; Figure 3 is an inlet end view of the air filter arrangement shown in Figure 1; Figure 4 is a cross-sectional view of the air filter arrangement shown in Figure 1, the cross-section being taken generally along line 4-4 of Figure 3; Figure 5 is a schematic perspective view of the z-filter medium; a type of medium preferably used in the primary filter cartridge of figure 2; Figure 6 is a plan view of the primary filter cartridge visible in Figure 2; Figure 6 being made facing the inlet face; Figure 7 is a cross-sectional view of the primary filter cartridge of Figure 6, the cross section being taken along line 7-7 of Figure 6; Figure 7A is a side elevational view of the filter cartridge shown in Figures 6 and 7; Figure 8 is an enlarged fragmentary view showing an interaction between a gasket element mounted on the primary filter cartridge and structural elements in certain housing components; Figure 9 is a perspective view of a preform usable for forming the filter cartridge of figures 6-7A; Figure 9A is an end view of the preform shown in Figure 9; Figure 9A being directed toward the end of the preform indicated in reference numeral 61, Figure 9; Figure 9B is a cross-sectional view taken generally along line 9B-9B, Figure 9A; Figure 9C is a cross-sectional view taken along line 9C-9C, Figure 9B. Figure 10 is a cross-sectional view of a mold arrangement including the preform of figure 9 with a medium package thereon positioned in a mold to form a sealing arrangement of the filter cartridge housing shown in figures 6-7A . Figure 10A is a fragmentary cross-sectional view of the arrangement of Figure 10 taken generally along its line 10A-10A. Figure 11 is a perspective view of a safety filter usable in the air filter arrangement shown in Figure 2; Figure 12 is a longitudinal cross-sectional view of the safety filter shown in Figure 11; Figure 13 is an end view of the safety filter of Figure 11; Figure 14 is a side elevational view of the safety filter shown in Figure 11; Figure 15 is a schematic representation of various groove definitions; Figure 16 is an exploded view of a second embodiment; and Figure 17 is a cross-sectional view of a mold arrangement, analogous to the mold arrangement shown in Figure 10, and showing an alternative embodiment of a preform.

DETAILED DESCRIPTION A. Revision The principles here are generally preferred features for maintainable filter cartridges. Serviceable filter cartridges can be used in a variety of arrangements, typically as primary air filter cartridges for air filters. The term "serviceable" in this context shall refer to a filter cartridge which, after a period of use, is removed and replaced with respect to the air filter. The term "primer" in this context is to refer to the filter cartridge in which a large portion of dirt or other contaminant passing through the filter medium in the air filter is charged.

In general, the features, techniques, and principles disclosed herein regarding filter cartridges can be applied to a variety of assemblies and arrangements. The particular arrangement depicted is a filter cartridge usable, for example, in a two-stage air filter, the air filter in general being of the type generally described in the above-mentioned PCT publication WO 03/08464. For this reason, other general features of the filter cartridge are described in detail. Additionally, the overall air filter is improved by using the filter cartridge according to the present preferred embodiment. B. Revision of the Set of Figures 1-4 In general, the techniques described herein are applicable to fluid filters. There are generally two classes of fluid filters with which techniques can be applied, namely liquid filters and gas filters. The embodiment depicted is specifically of an air filter (ie, a type of gas filter), and thus the features will be described in this context. The applicability of the principles and techniques described for liquid filters or for other gas filters will be apparent from the general descriptions. Reference number 1, figure 1, indicates an air filter arrangement. The particular air filter 1 shown is a two stage air filter comprising: a housing 2, an outlet flow duct 3 and a dirt ejector 4. In general, the air filter arrangement 1 also includes in the housing 2, as described below, a manageable (primary) filter cartridge (element) and an optional (or secondary) manageable safety filter cartridge (element). Here, the term "primary", when used to refer to a cartridge or filter element, is to refer to a filter cartridge that conducts most of the filtration that occurs through air passing through the medium within the assembly. In this case "filtration" means the removal of particulate material by the passage of fluid flow through the medium. The term "manageable" in this context is to refer to a filter cartridge that is configured to be periodically removed and replaced. (That is, the air filter can be serviced by removing one filter cartridge and installing another). A safety cartridge or secondary cartridge (or element) helps protect downstream components of the equipment in which the air filter assembly 1 is installed, for example, in case of primary filter cartridge failure or during maintenance of the primary filter cartridge. .

Earlier, it has been stated that the particular air filter 1 represented is a two stage air filter. By this it is understood that there was a pre-filter stage present upstream of the manageable primary filter cartridge. Equipment is provided that first causes the removal of dirt or other component from the first stage before air reaches the primary filter cartridge. The upstream component is generally a prefilter that operates without air passing through the medium, but instead uses a cyclonic or centrifuge approach for dirt separation.

Referring further to Figure 1, in general the air filter 1 shown is a preferred two-stage air filter having a cap 7, in this case a prefilter section 8 and a primary air filter section 9 The particular housing 2 shown is joined between the lid 7 and the primary air filter section 9 in the joint or region 11. In the housing 11 joint, the lid 7 and the primary air filter section 9 may be opened or separately for access to an internally received filter cartridge for maintenance. Here, a step of pivoting, or in some cases even removing, the housing cover 7 from the section containing the primary filter cartridge 9 will be referred to as a step of gaining service access to a filter element component. filter received internally, or alternatively as "opening" of air filter 1, for example for maintenance.

In general, air to be filtered enters air filter assembly 1 at an inlet end 12, passing individual cyclonic or centrifugal separators 13, prefilter 8. Separators of the type used in reference 13 could be conventional, and a The variety of types may be used, for example, in U.S. Patent Nos. 4,242,115 and 4,746,340, both of which are incorporated herein by reference. The particular prefilter 8 shown may lead to advantages. Within the separators 13, a first stage or dirt pre-cleaning occurs, and the separated dirt at this location is ejected from the prefilter 8 through the dirt ejector 4, in particular through the ejector tube 14 and ejector valve 15 Certainly, the process conducted on the prefilter 8 is not "filtration" as the term defined above, since the separation of dirt on the prefilter results from a centrifugal or cyclonic process, as opposed to a process of passing the fluid through. of a middle. The particular prefilter 8 shown is described in more detail below.

As an alternative, instead of a prefilter using a plurality of individual cyclonic or centrifugal separators 13, a prefilter arrangement generally characterized in US Patent Application No. 60 / 512,109, filed October 17, 2003, can be used. The full disclosure of application 60 / 512.109 is incorporated herein by reference.

Air exiting the prefilter 8 to the primary air filter section 9 then passes to: (a) primarily through an internally received primary filter cartridge, described in section C below; and (b) then through the safety element (optional) (described in section D below) and eventually into a clean air region to exit the air filter 1 through the clean air outlet duct 3. From duct 3 , clean air can be directed to any downstream equipment, for example, an engine air intake from an internal combustion engine or turbo charger.

Referring to Figures 1 and 2, cap 7 is generally pivoted to the primary air filter section 9 by brackets 16 and to quick release clips 17. Once the quick release clips 17 are loosened, the lid 7 may be opened relative to the primary air filter section 9 of at least 2 by pivoting the lid 7 (or prefilter 8) relative to the brackets 16. Alternatively the system may be configured to completely separate the lid 7 during the opening. (Note that in Figure 2A the quick release clips are not shown, but the assemblies 17a for them are).

Referring to Figure 1, the assembly 1 may be mounted on various machinery parts by the mounting brackets 19, for example using screws. In general, air cleaner 1 will be mounted with ejector tube 14 and dirt ejector 15 generally downward to facilitate dirt ejection. Mounting brackets 19 are shown in an example location. The specific type and location of mounting brackets will depend on the equipment on which the air filter 1 is to be mounted, and the preference for the downward direction of ejector tube 14 and dirt ejector 15. The relative location of ejector tube 14 around a perimeter of prefilter 8 is also a function of how air filter 1 should be mounted in use. The particular location shown at one of the narrowest (opposite) curved ends 8a of the prefilter 8 rather than one of the (opposite) sides 8b is convenient for many assemblies using principles in accordance with the present disclosure.

Still referring to Figure 1, air filter 1 may include a pressure gauge 3a and a connector 3b adjacent outlet 3 for conventional use. Connector 3b may provide, for example, filtered air flow to a crankshaft housing ventilation system.

Referring further to Figure 1, output 3 is a fixed stationary output. Alternatives are possible. In this regard, attention is drawn to FIG. 16, in which an exploded view of an alternative embodiment 400 is shown. Air filter 400 comprises a prefilter 401, primary filter element 402, optional safety element 403. , housing section 404, and outlet 405. Output 405 is a pivot or pivot piece, mounted with a snap fit in 406 and a pivot ring 407. Thus, it can be pivoted in housing 405 to outlet end 408. be directed in a variety of directions.

The other components 401, 402, 403 and 404 may be analogous to the same components described with respect to the other figures. Attention is now drawn to Figure 4, which is a fragmentary cross-sectional view of the assembly 1 shown from the perspective of line 4-4, Figure 3. Referring to Figure 4, the prefilter 8 is shown mounted on the primary air filter section 9, with the internally received primary filter cartridge 22 shown and with the optional internally received safety filter 20 shown. C. A Preferred Primary Filter Cartridge Referring to Figure 2, filter cartridge 22 is configured to allow direct flow; that is, it has a direct flow construction. By the term "direct flow" is meant herein that fluids flowing into the filter cartridge 22 for filtering enter the filter medium 26 of the filter cartridge 22 at the inlet end or face 23 in a first direction. and exit at the opposite outlet end or face 24 with the flow in the same general direction. The term "direct flow" as previously characterized should specifically differentiate a flow in a system such as that described in WO 89/01818 published March 9, 1989, in which air enters a cylindrical pleated filter element in the counter-direction. a cylindrical surface, and then exits the element (e.g., through an aperture) after turning about 90 °. Filter cartridge 22 has a side wall or outer surface 25 with a filter media pack 26 which is configured to filter particulates from a gas stream entering the inlet end or face 23 such that the gas stream leaving at the end or outlet face 24 is at least partially clean (i.e. particulate free). As shown in Figure 2, the filter cartridge 22 includes a housing gasket or housing seal 28 which aids in inhibiting leakage between the filter cartridge 22 and parts of the housing 2 in which the filter cartridge 22 is installed. The preferred gasket 28 extends completely peripherally about the outer sidewall 25 of the direct flow construction or cartridge 22.

As will be discussed in detail below, for preferred arrangements, the sidewall or outer surface 25 is formed of a preformed part (preferably a preformed molded plastic part) or preform 25a: (a) within from which the filter media pack 26 is positioned, (b) in which the filter media pack 26 is sealed; and (c) to which the housing seal 28 is secured. This preform 25a is discussed in more detail below with respect to the description of figures 6-7A and 9-9C at 60. The preform or perforated part 25a is sometimes referred to herein as a "shell", or as an "element housing". Not to be confused with the air cleaner housing 2. Certainly in use, the particular preform 25a shown is positioned to secure the media pack 25 within the air cleaner housing 2 with the housing seal 28 secured. between parts of the housing as discussed below with respect to Figure 8.

Preferred filter media packages 26 usable in primary element 22 of air filter arrangement 1 utilize a type of media, described below, generally referred to as "z-medium" or "z-filter medium". The z-filter spindle generally comprises a grooved (typically corrugated or creased) sheet attached to a cover sheet. Typically, the coating sheet for the z-filter medium is an uncorrugated uncorrugated sheet. In some cases, a sheet having corrugations extending perpendicular to the grooves of the grooved sheet may be used, see, for example, disclosure of provisional application US 60 / 543,702, filed February 10, 2004, and provisional application US 60. /543,804, filed February 11, 2004, both of which are incorporated herein by reference.

In general, the z-filter medium is arranged to form a set of longitudinal grooves (shafts) or air flow channels on one side of the corrugated or grooved medium, and another set of longitudinal (axial) flow channels in a opposite side of the grooved middle. The term "axial" with respect to the definition of longitudinal grooves shall refer to a direction of groove extensions generally between opposite faces 23, 24 of the media pack 26, typically referred to as the axial direction.

In operation, grooves in a set of grooves are designated as inlet grooves; are left open on one side, edge, or inlet end face of the middle; and are sealed or otherwise folded closed at one end, side or outlet face of the middle. Similarly, the grooves of a second set of grooves are generally referred to as output grooves; they are sealed or otherwise closed at the inlet side, edge or end face of the filter and are left open at the middle outlet side, edge or end face. In operation, air passes to the inlet flow face 23 of the media pack 26 by passing through the open inlet grooves at one end or upstream of the filter cartridge 22. Air cannot flow out of the ends of these inlet grooves, and so it has to pass through the filter means into the outlet grooves. The filtered air then passes out of an outlet end 24 of the filter media pack 26 through the open ends of the outlet grooves.

A variety of shapes, i.e. outer perimeter configurations, for primary filter cartridge 22 may be used. The particular form used in the arrangement of the drawings is a form of "two semicircles connected by parallel lines". The term "two semicircles connected by parallel lines" as used herein generally means an arrangement which is not circular in the shape of the cross section perimeter; the reference cross section being taken perpendicular to a groove extension direction, again sometimes referred to as the axial direction. (Of course, many of the techniques described herein can be applied to elements that have a perimeter shape or circular cross section). A variety of two semicircle shapes connected by parallel lines are possible, including, for example, oval and race track. In general, both of these two semicircle shapes connected by example parallel lines can generally be characterized by having two opposite curved ends with sides extending between them. A "running track shape" generally has opposite parallel sides extending between the two opposite curved ends. An oval shape generally has a slight curvature to opposite sides, typically with opposite sides positioned as mirror images of each other. The particular filter cartridge 22 shown is generally two semicircles connected by parallel lines, both in the cross-section of the preform or outer shell 25a and in the cross-section of the media pack 26, as will be apparent from the following descriptions. Typically, the ends (of transverse sectional shape) of the configuration of two semicircles connected by parallel lines are each semicircular.

Referring to Figure 5, the filter media pack 26 is generally made of a two-layer construction 45 formed of a cover sheet 46 attached to a grooved sheet 47 in this case corrugated. Typically, the media pack is a winding arrangement and the winding is conducted with the facing sheet 46 directed outwards, and the corrugated sheet 47 directed inwards. For the particular filter media pack 26 shown in Figure 5, the cover sheet 46 is an unrugged unrugged shape. Alternatively, a corrugated sheet perpendicular to the groove direction of the ridged sheet 47 may be used in some cases.

Medium comprising two-layer construction strips 45 formed of a facing sheet 46 secured to a grooved corrugated sheet 47 may also be formed into a medium package by stacking the strips together with a suitable drop of sealant therebetween. Such arrangements are generally referred to as "stacked z-filter media". The principles described herein may be applied to a stacked arrangement, however, the embodiment shown is particularly well suited for use with coiled arrangements.

In general, on one side 48 of the grooved sheet 47 a first set of grooves 49 is formed and on a second opposite side 50 a second set of grooves 51 is formed. In Figure 5, the edge 53 would correspond to the inlet face 23, figure 2, and the edge 54 would correspond to the outlet face 24, figure 2. The dashed lines in figure 5 indicate the winding of the two-layered construction 45 around of herself. The solid lines indicate an outer layer of the two represented layers resulting from winding.

In use, the first set of grooves 49 is closed adjacent an edge 54 and, in the second set of grooves 51, is closed adjacent the opposite edge 53. In general, when it is said that the grooves are closed "adjacent" to an edge , means that they are sealed along the edge or in a spaced position from the edge, but generally positioned close to the edge. When the grooves are said to be "sealed" when "closed," it means that they are both sealed by an applied sealant and otherwise distorted close to inhibit the passage of unfiltered liquid through the ends. A variety of sealing techniques can be used. Typically, a sealant is used. A sealer may be applied as a continuous strip between the groove sheet 47 and the cover sheet 46. The grooves may be distorted (e.g., dart-shaped) in the vicinity of one or both ends, advantageously. Other sealing techniques, without involving sealants, may be applied. Usable groove end sealing techniques include those described in PCT / US03 / 02799, filed January 31, 2003, provisional applications US 60 / 455,643, filed March 18, 2003, 60 / 466,026, filed April 25, 2003. 2003 and 60 / 467,521, filed May 2, 2003, and PCT application filed March 17, 2004, under express mail #EV 408495262 US and entitled "Improved Process and Materials for Coiling Z-Filter Media, and / or Closing Flutes of Filter Media; and, Products ", all of which are incorporated herein by reference.

From the review of figures 2 and 5, it should be apparent how medium 26 works. In general, grooves of the first set of grooves 49 are open in the inlet face 23, and thus comprise inlet grooves. They could be closed at their outlet ends 54 as a result of a drop of sealant or similar closure at this location. Thus, air entering the grooves of the groove assembly 49 at the inlet edge 53 must pass through means 26 to escape from the inlet grooves. As it passes through the media, filtration occurs and air flow enters a second groove (outlet) 51 at a location downstream of seal 53. Grooves in the groove outlet assembly 51 open along edge 54 , and thus the filtered fluid stream may flow out of the medium 26. This type of construction is generally characterized herein as z-filter medium. The z-filter means generally includes a plurality of grooves, each having an upstream portion adjacent an inlet flow face and a downstream portion adjacent an outlet flow face, the selected grooves being opened at the upstream and closed in the downstream part, and the selected grooves being closed in the upstream part and opened in the downstream part. Input and output faces do not have to be flat, however, it is a typical shape, shown in figures 4-7.

A variety of shapes and sizes of corrugations may be used in filter medium 26. Examples include corrugations which result in straight grooves, in which the grooves are parallel to one another and do not change shape from one end to the other, straight grooves having long or pressed end, and tapered grooves, wherein the inlet grooves gradually converge from a wide end toward a narrow end, with adjacent outlet grooves from a narrow end to a wide end in the same direction. Some examples of usable z-filter media configurations are described in the following references: 1. Standard grooves are represented in U.S. 5,820,646 and U.S. 5,895,574. 2. Tapered grooves, grooves with compressed ends and other variations in groove shapes are described in WO 97/40918, published November 6, 1997.

Full disclosures of the cited references (i.e., U.S. 5,820,646, 5,895,524 and WO 97/40918) are incorporated herein by reference.

In general, when the media pack 26 comprises a coiled medium, the coiling is of a medium strip sometimes referred to as a "single cutter", comprising the grooved middle sheet 47 secured to the cover sheet 46 by a drop of sealant. positioned between the two. The drop of sealant positioned between the groove sheet 47 and the single finish or combination media coating sheet 46 is generally referred to herein as a single face drop or sealant. Typically, when the resulting medium combination 45 is wound to form the wound medium package 26, it is wound with the facing sheet 46 directed outwardly, and with a second drop of sealant positioned adjacent an opposite end of the grooves relative to each other. to the single-sided droplet along an opposite side of the single-sided droplet cover sheet. This second drop is typically referred to as a "winding drop", since (a) it is formed generally immediately prior to winding or winding the combination of medium 45 and (b) its sealing function is provided as a result. winding

When the media pack 26 is formed by winding the medium configuration 45 with a winding drop therein, a winding drop sealant region is generally positioned facing the inside of the winding. The medium can then be compressed in this region by sealing opposite sides of the winding drop material at this location advantageously. This is described, for example, in U.S. Provisional Application 60 / 467,521, filed May 2, 2003, incorporated herein by reference. It is also described in application 60 / 467,521 that a urethane material may be advantageously used at this location. Disclosure 60 / 467,521 was filed as part of a PCT application on March 17, 2004 with express mail #EV 408495263 US and entitled "Improved Process and Materials for Coiling Z-Filter Media, and / or Closing Flutes of Filter. Media; and, Products ". The full disclosure of this PCT application is also incorporated herein by reference.

With respect to the preferred media package 26 of cartridge 22, Figure 7, the winding drop would typically be positioned adjacent the inlet face 23, with a single finish drop adjacent the outlet face 24. A core 57 extends to the end. media pack 26 adjacent to outlet end 24. Adjacent face 23, where the winding droplet is located, would be in a less convenient location to insert core 57. Also, this type of construction avoids the need for a seal adjacent to the output face 24 between the media pack 26 and the core 57.

In general, when the medium pack 26 is a coil, on an inner side of the coil a leading end of the medium combination 45 is present. It may be desirable to seal this fully closed lead end by combining the medium with a sealer prior to winding. In some arrangements, such a seal at this location may be avoided because of the presence of the adjacent end of the winding drop 23 by closing a central portion of the media package 26 adjacent the inlet end 23.

Similarly, on the outside of the media pack 26, an outlet end of the coiled medium combination 45 is present. It may be sealed closed with various sealants, such as polyurethane or hot melt sealants, in the desired manner. In some cases, the presence of the seal 28 described below overlapping with a portion of this outlet end in a region adjacent the face near the winding drop 23 may attenuate the critical condition of a seal at this location. The sealant used in the single finish and the winding drop may be the same or different, and a variety of sealant materials may be used. Typically, hot melt sealants or foam sealants such as polyurethanes will be used. A description of sealant for forming related media packs is provided in the provisional application U.S. 60 / 467,521 incorporated.

If the take-up droplet does not provide sufficient closure adjacent the inlet end 23, extra sealant may be added at this location in the central part of the media pack 26. This is generally described in provisional application 60 / 467,521. The term "corrugated" used herein to refer to the structure in the middle shall refer to a groove structure resulting from the passage of the medium between two corrugation rollers, that is, in a passage or bite opening between two rollers each of which have appropriate surface features to cause a corrugating effect on the resulting medium. The term "corrugation" should not refer to grooves that are notched and bent or otherwise formed by techniques that do not involve the passage of the medium in a bite between corrugation rollers. However, the term "corrugated" should be applied even if the medium is further modified or deformed after corrugation, for example by folding techniques described in PCT / US03 / 20799, incorporated herein by reference.

Corrugated medium is a specific form of grooved medium. Grooved middle is a medium that has individual grooves (e.g., formed by corrugation or folding) that extend through it.

In general, corrugated sheet 47, Figure 5, is of a type generally characterized by having a regular curved groove or corrugation pattern. The term "wavy pattern" in this context shall refer to a groove or corrugated pattern of alternating valleys and ridges. The term "regular" in this context should refer to the fact that pairs of alternate ridges and valleys generally have the same shape and size of repetitive corrugation (or groove). (Also, typically each valley is substantially the inverse of each ridge). The term "regular" in this manner shall indicate that the corrugation pattern (or groove) comprises valleys and ridges with each repetitive pair (comprising a valley and crest), without substantial modification in the size and shape of the corrugations over at least 70. % of groove length. The term "substantial" in this context refers to a modification resulting from a change in the process or shape used to create the corrugated or grooved sheet, as opposed to secondary variations arising from the fact that the middle sheet is flexible. With respect to the characterization of a repeating pattern, it does not mean that in any given filter construction an equal number of ridges and valleys is necessarily present. The medium could be terminated, for example, between a pair comprising a crest and a valley, or partially along a pair comprising a crest and a valley. Also, the ends of the valleys and ridges may vary from one to another. Such variations in the extremities are disregarded in the definitions.

In the context of characterizing a "curved" corrugated corrugated pattern, the term "curved" is to refer to a corrugated pattern that is not the result of a folded or pleated shape provided in the middle, but rather the apex of each ridge and the base of each valley is formed along a radius curve. A typical radius for such a z-filter medium would be at least 0.25 mm and typically no more than 3 mm.

A further feature of the particular curved regular wavy pattern shown in FIG. 5 for corrugated sheet 47 is that approximately at the midpoint between each valley and each adjacent ridge along most of the length of the grooves is a transitional region where the curvature is invert.

A feature of the corrugated sheet of the particular regular curved wave pattern shown in Figure 5 is that the individual corrugations are generally straight. By "straight" in this context is meant that through at least 70%, typically at least 80% of the length between opposite edges 53, 54 the valleys do not substantially change in cross section. The term "straight" with reference to the corrugation pattern shown in FIG. 5 partly distinguishes the corrugated conical groove pattern described in FIG. 1 of WO 97/40918, the complete disclosure of which is incorporated herein by reference. The tapered grooves of FIG. 1 of WO 97/40918 would be a curved wavy pattern, but not a "regular" pattern, or a straight groove pattern, no way the terms are used.

For the particular arrangement shown above in Figure 5, parallel corrugations are generally completely straight through the middle, from edge 53 to edge 54. Straight ridges or corrugations may be deformed or bent at selected locations, especially at the ends. Modifications at the groove ends are generally disregarded in the definitions given for "regular", "curved" and "wave pattern".

In general, the filter medium is a relatively flexible material, typically a non-woven fibrous material (of cellulose fibers, synthetic fibers or both) typically including a resin, sometimes treated with additional materials. Thus, it can be shaped or shaped into various bent or corrugated patterns without unacceptable damage to the medium. Also, it can easily be wound or otherwise configured for use, again without unacceptable damage to the medium. Of course, it has to be of a nature such that it maintains a corrugated or bent configuration during use.

In the corrugation process, an inelastic deformation is caused in the medium. This prevents the medium from returning to its original form. However, once the tension is released, the groove or corrugations will tend to spring back, recovering only a part of the stretching and bending that has occurred. The coating sheet is generally adhered to the grooved sheet to inhibit the spring effect.

Also, in general, the medium contains a resin. During the corrugation process, the medium may be heated above the resin glass transition point. When the resin then cools, it will help keep grooved shapes.

Both of these techniques are generally known in practice with respect to the formation of the corrugated medium.

One problem with z-filter construction concerns the closure of individual groove ends. Typically, a sealant or adhesive is provided for closure. As is apparent from the discussion presented, on a typical z-filter medium, especially one using straight grooves, as opposed to tapered grooves. Large areas of sealant surface (and volume) at both upstream and downstream end are required. High quality seals at these locations are critical to the proper operation of the resulting media structure. The high volume or sealant area creates problems with this. Attention is again drawn to Figure 5, in which a construction of z-filter media 26 using a regular curved corrugated pattern corrugated sheet 47 and an unrugged flat sheet 46 is shown. A distance (D1) defines the extent of the flat medium 46 in a region below a given corrugated groove. A length (D2) from the arcuate medium to a corrugated groove in it, distance D1 is certainly greater than Dl, because of the shape of the corrugated groove. For a typical evenly shaped medium used in grooved filter applications, a linear length D2 of the grooved medium between contact points with the non-grooved medium will generally be at least 1.2 times Dl. Typically, D2 would be in a range of 1.2 - 2.0 inclusive. A particularly convenient arrangement for air filters has a configuration in which D 2 is about 1.25 - 1.35 x D1. Such medium has been used commercially, for example, in Donaldson Powercore ™ z-filter arrays. Here, the D2 / D1 ratio will sometimes be characterized as a groove / flat ratio or drag from middle to corrugated medium.

In the corrugated cardboard industry, several standard grooves have been defined. For example, standard E groove, standard X groove, standard B groove, standard C groove, and standard A groove. The attached figure 15 in combination with table A below provides definitions of these grooves.

Ponaldson Comapny, Inc. (DCI), the inventor of the present disclosure, used variations of standard A and standard B grooves in a variety of filter arrangements. These grooves are also defined in Figure 15 and Table A. TABLE A_______________________________________________________ Groove A Standard: Groove / Flat = 1.53: 1, radii (R) are as follows: R1Q19 = 0.0720 inch ¢ 1.829 rare); R1020 = 0.0620 inch (1.575 rams). Certainly other industry standard corrugated groove definitions are known.

Generally, industry standard corrugated box groove configurations can be used to define corrugated shapes or approximate corrugated shapes for the corrugated medium. Comparisons between the DCI A groove and the DCI B groove and the corrugation industry standard A and standard B grooves indicate some convenient variations.

Referring again to Figure 2, preferred (primary) filter cartridge 22 is manageable. By the term "manageable" is meant herein that the filter cartridge 22 may be removed from the air filter assembly 1 and either refurbished or replaced. In typical systems, the filter element 22 is periodically replaced during a maintenance operation by the installation of a new replacement cartridge. The particular preferred filter cartridge 22, figure 7, comprises the following components: preform (shell) 25a; middle pack 26, centerpiece or core 57, receiver 58, grid 59 and sealing member or gasket 28. (Grid 59 is more readily seen in Figure 2). Preferred sealing member 28 is generally positioned to completely circumscribe the media pack 26 and thus separate the opposing flow faces 23, 24 from the media pack 26 from each other with respect to the flow around the media pack 26. For the particular arrangement shown, the sealing member 28 is positioned to completely circumscribe the media pack 26 and is mounted on the preform 25a. For the particular preferred arrangement shown, the sealing member 28 is positioned with the axial sealing surface 28a positioned at a distance no greater than 15 mm, and preferably no more than 8 mm from the inlet face 23, although alternatives are possible.

It is noted that in the diaphragms the main body or direct flow construction of the media pack 26 is shown schematically in the cross sections. That is, the groove detail is not shown. Like the groove detail, it is not shown in any form other than example 5 for convenience. As previously indicated, a variety of groove shapes may be used. Examples depicting the ends of a z-filter element and sealing those ends are provided in the U.S. Des. 396,098, U.S. 6,190,432, U.S. Des. D450.827, U.S. 6,235,195, U.S. D437,402 and U.S. D450,828, all of these six references being incorporated herein by reference.

Referring specifically to Figure 6 and the cross-section shown in Figure 7, regions 26a show where the media pack 26 has been cut to cross-section to provide the design of Figure 7. Region 26b indicates a region where the cross-sectional line 7-7, Figure 6, is positioned between the layers of the wound media package 26, with the visible surface at 26b being a corrugated surface. A cross section similar to Figure 7 results by guiding the cross section line, Figure 6, through the coiled layers at opposite curved ends, but between layers across the central region.

As discussed in more detail below, the core 57 is generally positioned to separate the coiled medium layers, wherein each layer comprises a grooved sheet attached to the non-grooved sheet.

Referring to Figures 6-7A, for the preferred embodiment shown in preform (shell) 25a, core 57, receiver 58 and grid 59 are all integral with each other. By "integral" is meant in this context that the identified parts cannot be separated from each other without damage to the defined unit. Collectively, such identified parts comprise preferred preform 60. Preform 60 is prepared before the cartridge 22 is assembled. Cartridge 22 is typically assembled by inserting media pack 26 and preform 60 into a mold and molding seal 28 in place. This is described in more detail below.

Still referring to Figures 6-7A, preferably preform 60 comprises a molded plastic material, such as a polypropylene. An example of a usable material would be a 25% glass loaded, 10% mica loaded polypropylene such as a Thermofil or an Adell polypropylene.

Referring to figures 9-9C, preform 60 includes opposite ends 61, 62 with sidewall 63 extending therebetween. Adjacent to the end 61, the sidewall 63 has an outwardly funnel-type transition portion 64, Fig. 9B, with housing sealing support 65, comprising a racially outwardly directed sealing support portion or ferrule 65a therein. Ferrule 65a has sealing flow apertures 66, figure 9A therethrough for use in the manner further described below. In general, the sealing support of the housing 65 will generally be characterized as radially directed since it is directed radially outwardly of a longitudinal axis 67 of preform 60, Figure 9B.

As shown below with respect to the description of FIGS. 10, 10A, the funnel-like transition portion 64 opens to a space such that the sealant may flow during assembly. Preferably, at the outer edge 64a, Fig. 9C, the transition portion 64 extends outwardly enough to create clearance for the convenient flow of sealant therein during assembly.

In the extension between regions 67 and 68, the sidewall 63 may have a tapering slightly downward (or inwardly) for convenience.

In preferred arrangements, sidewall 63 will be impermeable along its length, although alternatives are possible. Also, preferably, the sidewall 63, in combination with the seal 28, will extend at least the full axial length of the media pack 26, although alternatives are possible.

At the end 62, the grid mechanism 59 is provided in extension through the opening 70. The grid mechanism 69 can have a variety of shapes. The particular shape provided (Figure 9A) comprises parallel crosspieces 72, center crosspiece 73 and diagonal crosspieces 74. In general, the grid mechanism 69 is positioned to support the outlet face 24 of the media package 26, figure 7 . The grid mechanism 59 inhibits the telescopic action of the medium. The center crosspiece 73 defines a hollow elongated center receiver 75 therein, forming the receiver 58, figure 7. The receiver 75 preferably has an external aspect ratio (outer length L figure 9A by outer width W figure 9A) of at least 3: 1, preferably at least 5: 1, more preferably in the range 6: 1 to 10: 1. Typically, and preferably, the outer width W, Fig. 9A, is not greater than about 65%, preferably no greater than about 50% of a larger cross-sectional dimension of the filter pack.

Referring to figures 9B and 9C, preferably the receiver 75 comprises a part of a center hole 76 including the receiver 75 and non-hollow center blade 78. Also, preferably, a divider 79 is provided on the receiver 75 (figure 9B) for splitting the receiver 75 on two sides 75a and 75b. preferably each side extends inwardly from edge 80 to end 81 at least 10 mm, preferably no more than 35 mm. The typical depth for each side would be about 15 mm and 28 mm. Preferably, the shape of each side is as shown in figure 9B.

Referring to FIGS. 6 and 7, external surfaces of receiver 75 comprise a core projecting within the wound media pack 26. Typically, the wound media pack 26 would be formed in the spool, and then inserted over the receiver 75. That is, in typical assembly the media pack 26 would not be wound with the core 76 in position. Instead, the media pack 26 would first be constructed in its wound form, and then would be inserted into preform 60a 60 by end 61 and would continue to be pushed inward to push blade 57 (78) between the middle package layers 26, guiding the core 75 into position. The slightly triangular shape and relative fineness of the blade 78, figure 9B, facilitate this assembly.

More specifically, extending from the inner end 75c (Figures 9B and 9C) of the receiver 75 axially into the shell 25a is provided a central blade or palette arrangement 78. The pallet 78 preferably comprises a non-hollow triangular shaped blade 78a preferably not more than 3.0 mm thick between regions 75c and 78b; and not more than 2 mm thick at tip 78a. Typically, adjacent region 75c of blade 78 is about 2 mm thick, and at tip 78b is about 1.0-1.5 mm thick (e.g. 1.3 mm) with a taper in the range. The relatively thin non-hollow blade 78 facilitates pushing the media pack 26 into the shell 25a with a portion around the receiver 75. The blade 78 is preferably triangular in shape, with a round tip 78a opposite the receiver 75.

Preferably, the blade arrangement 78 projects into the media pack at a distance from the outlet end 24 at least 30% of the axial length of the media pack, typically at least 40% of this length. Preferably, the blade 78 does not extend beyond 75% of the axial length of the media pack, typically not more than 60% of this length, and thus the blade 78 is spaced apart from the opposite end surface 23 of the media pack 26. FIG. 17 shows filter cartridge 22 with an alternative embodiment of a preform 360. The particular arrangement in figure 17 shows filter element 22 within a mold arrangement 397, to be further described below. Filter cartridge 22 is shown in cross sectional view, and an alternative central pallet or blade arrangement 378 can be seen. The blade 378 facilitates pushing the media pack 26 into the shell 325a. The blade 378 is preferably triangular in shape with a round tip or apex 378b. The blade 378 of FIG. 17 differs from the blade 78 of FIG. 9b in that the apex 378b is offset from the central axis 67. That is, the apex 378b is located off the side of the axis 67. The blade 378 has the general shape of a triangle. straight, rather than the equilateral or isoscopic triangle appearance of figure 9. Blade 378 generally has the same thickness and depth of penetration in the middle 26 as blade 78. Blade 378 is formed with apex 378b displaced from the central longitudinal axis 67 for ease and convenience of pushing blade 378 between the layers of the media package 26. When the apex 378b is displaced from the central longitudinal axis 67, the blade 378 first enters between the more middle layers 26 near the back in the wound media pack 26. In the back portion of the wound media pack, the middle layers 26 are not as tightly packed, for example, as exactly the center of the media pack, and this creates a larger clearance between the middle layers, which facilitates easier insertion of the blade 378 between the coiled middle layers. Attention now turns to Figure 7, in which sealing arrangement 28 is shown attached to the ferrule or flange 65 (i.e. housing sealing bracket) of preform 60. This is also shown in exploded view in Figure 8

Referring to Figure 8, seal 28 is molded directly into ferrule or holder 65. In addition, an integral part 90 of seal 28 is molded directly into middle pack 26 in 91, sealing seal 28, preform 25a and packet. 26 in each other at this location. The seal 91 is preferably directly formed on the cover sheet 46 and preferably completely around the media package 26. The seal 91 also preferably begins on a part of the media package 26 adjacent one of the flow faces, in this case the flow face 23. Preferably, seal 28 does not include any portion extending over a flow face.

Referring to figure 8, seal 28 is an axial handle seal with respect to housing 2. In particular, it is gripped between housing sections 7 and 9, in particular housing extensions 9a and 7a. . Typically, seal 28 will be configured to compress thickness when installed. Preferred seal materials 28 comprise foaming sealant materials, such as foaming polyurethane, which can easily compress to form a strong seal. Usable polyurethane seal materials include those described in U.S. Patent 6,350,291 and U.S. Application 10 / 112,097, filed March 28, 2002, both of which are incorporated herein by reference, although alternatives are possible.

As described, seal 28 is specifically an axial handle seal (or axial housing seal). It may be configured with relatively flat opposing surfaces 28a, 28b, or with opposing surfaces having a ridge or notch therein. Alternative seals may be used, including radial seals.

In general, surfaces 28a, 28b comprise regions of the locking seal at least since it is these regions that engage the housing during sealing.

A method usable for generating this type of sealing arrangement can be understood with reference to figures 10, 10A and 17 and the following description. In Figure 10, the media pack 26 is shown inserted into an interior 60a of preform 60. It should be understood that the media pack 26 would be positioned with the core 76 projecting into the media pack 26 between the middle layers. The assembly 95 comprising the shell 60 and the media pack 26 are shown positioned in the mold arrangement 97. The mold arrangement 97 includes a mold base 98 and a mold cover 99 defining the cavity 100 therebetween. Cavity 100 is configured to form seal 28. Seal 28 is formed by pouring a curable resin into mold cavity 100, preferably after assembly 95 is positioned at base 98 and before cap 99 is in place. In operation, a foaming urethane (which will preferably swell at least 20%, typically at least 40% and usually 50-100% during curing) would be used.

Prior to curing the resin, the mold cover 99 would be set in position. The mold cover provides the definition of a seal portion 28. During molding, the resin rises to fill cavity 100. This rise generally involves flow through openings 66 in the housing seal holder 65, figure 9A. As a result of the flow through these openings, after curing, the seal 28 will be mechanically attached to the seal holder 65 by virtue of a portion of the resin being cured and left in extension through the openings 66. The sealing of a portion of the seal Cured 28 directly into the media pack 26a will also occur in region 100, since in this region the resin will come into direct contact with the media pack. Flow through the end surface 23 will generally be impeded by the inclined region 102 of the cavity 100 that engages the media pack 26. If flash inhibition is required at this location, the media pack 26 may be fixed by the mold in this region; or, a thixotropic drop may be placed between the media pack 26 and the mold base 98 at this location.

Referring to FIG. 10A at 103, the funnel surface 64 (FIG. 9B) of preform 60 creates an upward diagonal surface toward the media package 26. This inclination will help direct the resin to the media package, It will also inhibit air trapping at this location during the molding process. Figure 17 illustrates an alternative embodiment of a method for generating preferred types of sharp sealing arrangements described in Figure 17, the media pack 26 is shown inserted into an interior 360a of a preform 360. assembly 395 comprising a shell 360 and media pack 26 are shown positioned in the mold arrangement 397. The mold arrangement 397 includes a mold base 398 and a mold cover 399 defining a cavity 400 therebetween. Cavity 400 in this embodiment is shown filled with resin 401. Cavity 400 is configured to form seal 28. Seal 28 is formed by dispensing a curable resin into mold cavity 400, preferably after assembly 395 is positioned at the base. 398 and before cap 399 is in place. In operation, a foaming urethane would be used. A foaming urethane would preferably swell at least 20%, typically at least 40%, and usually 50-100% during curing.

Before the resin cures, the mold cover 399 would be set in position at base 398. The mold cover 399 provides the definition of a part of seal 28. During molding, the resin will rise into the mold cavity 400. This Ascent would generally involve flow through the openings 66 in the housing sealing bracket 65 (Figure 9A). As a result of flow through these openings, after curing, the seal 28 will be mechanically secured to the seal holder 65 because a portion of the resin is cured and left in extension through the openings 66.

Thus, advantageously, the seal 28 (Fig. 8) for arrangements according to the present disclosure allows both: sealing portions of the housing as indicated in 28a, 28b and opposite surfaces to seal with a housing in use; and a portion 28c integral with the sealing portion of housing 28a which allows a seal directly in the middle 26, a seal around the media package 26 and a media package seal 26 and preform 60, 360 ( or 25a). Such sealing parts (28a, 28b, 28c) are preferably integral with each other and are molded simultaneously from a single resin casting. By "integral" is meant herein preferably regions 28a, 28b, 28c which are all parts of the same cure or well or volume of resin, without separation between them. This is preferable for convenient mounting without multiple sealing steps.

Referring to Figure 8, preferred shape of seal 28 includes upwardly directed (toward end 23) portion 28d from surface 28a; with part 28e directed opposite to fill a region between the surface of the funnel 64 and the media pack 26. Regions 28a and 28b are positioned on opposite sides of the ferrule 65, with the transition part 28f preferably positioned at to extend between them. Angle A, the acute angle between the media pack 26 and the funnel surface 64, preferably extends at an angle A in the range of 30 ° to 60 ° inclusive, more preferably 35 ° to 55 ° inclusive.

This type of molding operation uses some principles related to that described in provisional application U.S. 60 / 532,783, filed December 22, 2003, the full disclosure of which is incorporated herein by reference. Some of the techniques used in this application may be applied to provide the sealing arrangement shown in FIG. 8. Note that the location and particular shape of the present seal of FIG. 8 are quite different, as well as the location and nature of the precast part. form used. Additionally, the specific example seals shown are of different types with respect to how the housing is preferably fitted.

Although the media packs may be made in a variety of sizes and shapes, a typical media pack used in the specific embodiments shown will have an axial length of at least 140 mm, and an axis at greater cross-sectional length of at least 190 mm and an axis in the smallest cross section or length of at least 110 mm.

Referring to Figure 8, in general the interface between the media pack 26 and the seal sealing material 28 is at an extension distance along the media pack of at least 4 mm, and typically 5-15 mm. This extension helps provide a good secure fit between the media pack 26 and the seal 28. In addition, the seal 28 will operate for a certain damping effect with respect to the vibration of the rigging in which the assembly 1 is installed which is undesirably transmitted. media pack 26, potentially damaging media pack 26 at this location. That is, the desirable damping effect of material 28 facilitates the integrity of filter cartridge 22 during use. C. Usable Safety Filters Referring to Figures 11 - 14, one embodiment of a usable safety filter 20 is illustrated. In preferred systems, the safety filter 20 is oriented on the air filter 1 downstream of the primary filter cartridge 22 In order to protect downstream components from debris that may pass through the primary filter cartridge 22 in the event of a primary filter cartridge failure 22. In addition, safety filter 20 helps protect the engine during maintenance of the air filter 1 at the same time preventing debris from falling into the clean air region 32, figure 4. The safety filter 20 has an outer periphery 170 which preferably generally matches the outer periphery of the primary filter cartridge 22. In the embodiment illustrated , the safety filter 20 is in the form of two semicircles connected by parallel lines, but may be of other forms, such as circular. The particular two parallel-line semicircles shape shown is a running track shape with a pair of opposite sides 172, 173 joined by a pair of round or curved opposite ends 174, 175.

In the embodiment illustrated, the safety filter 20 includes a rigid structural frame 178. Forming a portion of the frame 178 is a skirt or strip 180. The strip 180 circumscribes an inner region of filter means 184. A variety of media types 184 may be used. In the configuration shown, means 184 is pleated, with pleats 185, figure 11, extending parallel to straight sides 172, 173. Pleat densities of at least two pleats per inch (25.4 mm), and typically 3- 8 pleats per inch (25.4 mm) are usable, for example. In Figure 11, one can see how there are two pleat regions 186, 187. The first pleat region 186 is separated from the second pleat region 187 by a partition 188 of the frame 178 which generally bisects the safety filter 20. The bisector wall 188 extends longitudinally along the safety filter 20 between curved end 174 and curved end 175.

In the preferred embodiment, the security filter 20 includes a cable 190 that is sized to accommodate at least a part of a human hand. "Sized to accommodate a part of a human hand" means that the cable 190 has structure between it and the remaining part of the security element 20 which allows at least one part of the hand (a finger or fingers) to be fitted between the cable structure and the rest of the safety filter 20 to allow the safety filter 20 to be manipulated.

In the embodiment shown, the security filter 20 includes a cable 190 protruding from the frame 178. In preferred embodiments, the cable 190 is an integral extension of the partition 188. A variety of cable constructions 190 are usable. In the construction shown, the cable 190 has at least one projection 192 which extends from the structural member 190. The projection 192 may have various configurations including buttons, rings, extensions, etc. In the embodiment shown, projection 192 takes the form of an arm 194 defining a void 196, figure 12. In preferred embodiments, the void 196 completely traverses arm 194.

In particular preferred embodiments, cable 190 includes a second projection 198. Second projection 198 may also take a variety of shapes or configurations. As shown, projection 198 has the same shape as projection 192, in the form of an arm 202 having a void 204 (FIG. 12) therebetween.

The void sizes 196, 204, in preferred embodiments, are large enough to accommodate a gloved finger of a human hand to assist in manipulating the safety element relative to air filter 1. For example, voids 196, 204 define a transverse sectional area of at least 2 cm 2, typically 4 - 100 cm 2. Projections 192, 198 are separated from each other by a platform 206, figure 12, in partition 189.

In preferred uses, the volume 205 defined by platform 206 and the inner sides 207, 208 of each projection 192, 109 accommodates the apex 152 (figure 7) of centering construction 79 of core 57, see figure 4. In such preferred uses, projections 192, 198 operate as guides 212, 214 (figure 12) to help operationally orient primary filter cartridge 22 into place in air filter 1. Guides 212, 214 can be sized to help center and place cartridge 22 inside the air filter 1.

Still referring to figures 11-14, preferred safety filter 20 includes a sealing member 218 to help form a seal 220 (figure 4) between the safety filter 20 and the air filter section 9 of housing 2. filter shown, sealing member 218 is secured to tape 180 around the entire periphery of tape 180. Sealing member 218, in one shown, forms a radially directed seal 221 (figure 4) between and against strip 180 and the inner surface 120 of the air cleaner 9 section of the housing 2. Usable medium 184 may include many different types of conventional filter media. This includes cellulose, synthetic and various blends. One usable filter medium is a synthetic fiber / glass blend having a weight of 70 ± 4.0 lb / 3,000 ft2 (114 ± 6.5 g / m2); a thickness of 0.032 ± 0.003 inch (0.81 ± 0.08 mm); a Frazier permeability of 165 ± 20 ft / min (50.3 ± 6.1 m / min); a pore size of 100 ± 8 microns; a dry tensile strength of 19.8 ± 6.6 lb / in (9.06 ± 3 kg / in), and a burst strength of 20 ± 5 psi (138 ± 34 kPa). D. Usable Prefilter Constructions In Figures 2-4, a section of the preferred prefilter 8 is illustrated. Although several different conventional prefilters may be used upstream of the primary filter element 22, the particular prefilter 8 illustrated can be used to advantage.

As previously mentioned, the prefilter 8 includes a plurality of centrifugal separator tubes 13, figure 2A. Each of the tubes 13 includes a substantially cylindrical wall around 228 which is tapered between opposite ends 229, 230. End 229 has a smaller diameter than end 230. End 229 will be oriented upstream of end 230. Located within the Wall 228 is a vortex generator 232, Figure 3, including curved pallets or pallets 234. Wall 228 also includes at its downstream end 230 an outlet port 236, Figure 2A.

Each of the tubes 13 is received within an upstream deflector plate 238, figure 2A. The baffle 238 includes a plurality of openings 240 sized to receive the upstream end 229 of the pipes 13. The upstream end 229 of each of the pipes has a tongue 242 (FIG. 3) which is received within a slot 244 Fig. 2A which is part of the opening 240. This tongue / opening forms an indexing arrangement 246 (Figure 3) which ensures that each of the outlet holes 236 in each of the pipes 13 is pointed towards the delivery pipe. dirt ejection 4. Preferred prefilter 8 shown also includes a plurality of extraction tubes 250, figure 4, which is received within the tubes 228. In preferred embodiments, each extraction tube 250 is molded as an integral part. As such, in preferred embodiments, the cap 7 includes as an integral molded one-piece member, the sidewall 252, the tube 14, a downstream deflector plate 254 and each of the extraction tubes 250.

To assemble the prefilter 8, each of the tubes 228 is inserted into a corresponding opening 240 in the bending plate 238. The indexing arrangement 246 is used to align the tongue of each of the tubes 228 into a corresponding slot 244 to ensure outlet port 236 points toward ejector tube 43. Upstream deflection plate 238 with each tube 228 installed therewith is then oriented over remaining portion of prefilter 8. Each end 230 of tubes 228 is oriented over a corresponding extraction tube 250, and the baffle plate 238 is secured, as by a pressure fitting, to the side wall 252. The prefilter 8 operates as follows: a gas-flowing stream containing matter The particle flow passes through the upstream end 229 of each of the tubes 13. The flow is induced to rotate by the vortex generator 232. The rotating nature of the flow stream causes centrifugal forces to act on the particulate matter. in the gas flow stream. Particulate matter is heavier than gas in the flow stream and migrates toward wall 228.

The particles are ejected from the outlet ports 236, while the remaining gas stream flows through the exhaust pipes 250. From the exhaust pipes 250, air flows downstream and into the upstream flow face 23 of the exhaust element. primary filter 22. Particulate matter that is ejected from outlet holes 236 falls by gravity through ejection tube 4 and out through ejection valve 15. E. Methods In general, a method of sealing the element is provided. filter having a direct flow construction as described. The preferred method generally includes opposing flanges for positioning a cap and a primary air filter section as described in engagement with the projecting axial sealing gasket (on the element) and axially compressing the gasket as shown. A method is provided for mounting a sealing gasket on a filter cartridge having a direct flow construction as described. An exemplary method generally includes sealing a preform and media pack together with the same leakage of sealing material that will form a seal from the housing to the cartridge.

To clean the gas, first the filters (20, 22) must be installed inside the air filter 1. The cap 8, containing a prefilter, is removed from the air filter section 9 of the housing 2. security 20 is provided. Safety filter 20 is handled and manipulated by holding cable 190, such as placing fingers through gaps 196, 204. Safety filter 20 is placed through the open end of the air filter section and installed inside the part. 32. Gasket 220 is compressed between and against wall 9 to form a radial seal 221 between safety filter 20 and air filter section 9.

Referring to Figure 4, then, the primary filter cartridge 22 is provided. Primary filter cartridge 22 is manipulated such that the downstream end 24 is first placed through the open end of the air filter portion 9 The receiver 75 is aligned with the guides 212, 214 to be received therein. In particular, core 57 has receiving pockets 164, 167, figure 4, which receive the guides 212, 214 therein. The centering frame 512 of the core 57 interacts with the guides 212, 214 to help align and center the primary element 22 within the air filter section 9. Primary filter cartridge 22 is centered in the above manner and oriented in such a manner. gasket 28 abuts flange 371 of air filter section 9. Thereafter, prefilter section 7 is oriented over air filter section 9 so that flange 370 rests on gasket 28. The quick release latches or clamps 17 are then used to apply axial force to gasket 11 and form an axial seal with gasket 28 between the housing prefilter section 7 and the housing air filter section 9. Flange 370 includes peripheral extension 370a, figure 8, to cover outer annular portion 28f of seal 28.

To clear the air, air enters the prefilter 7 through centrifugal tubes 13. Vortex generator 232 causes the gas flow to rotate, which causes particulate matter to migrate toward walls 228. Particulate matter is then ejected through the outlet ports 236 to gravity fall through the dirt ejector tube 14. The pre-cleaned air then flows through the extraction pipes 250 and then through the inlet face 23 of the primary filter element 22. medium 26 removes additional particulate matter from the air. The clean air then passes through the outlet face 24. Then the clean air passes through the middle 184 of the optional safety filter 20, and then through the outlet pipe 3. Then, the clean air passes to the downstream equipment, just like an engine.

After a period of use, air cleaner 1 will require maintenance. To service the air cleaner 1, the air cleaner section 7 is removed from the air cleaner section 9 of housing 2. This is done by loosening the clamps. When the clamps 17 are loosened, this loosens the axial seal formed by the sealing gasket 28. The upstream face of the filter cartridge 22 is then exposed. Filter cartridge 22 is picked up and removed from air filter section 9. Primary filter cartridge 22 may be disposed of or recycled in convenient applications. If the safety filter 20 also needs maintenance, the cable 190 is caught, and the safety element 20 is removed from the air filter section 9 and thrown away or recycled. It is to be understood that in many applications the primary filter cartridge 22 will require replacement while the safety filter element 20 will not require replacement.

If the safety filter 20 is being replaced, then a second new safety filter element 20 is inserted into the housing 2 as described in the previous initial installation description. Then a new primary filter cartridge 22 is provided and is installed within the air filter section 9 as described above. The prefilter section 8 is placed over the air filter section 9, and the axial seal is formed with gasket 28.

Claims (20)

1. Air filter cartridge (22) comprising (a) a z-filter media package (26) comprising grooved media trapped in the coating means, the media package (26) having an inlet flow face (23), an outlet flow face and an axial length between the inlet flow face and the outlet flow face CHARACTERIZED by the fact that the cartridge comprises: (b) a preform (60) having a side wall portion circumscribing the media pack (26); the preform (60) including a sealing support portion of the housing (65); and (c) a housing sealing arrangement; the molded housing sealing arrangement for the means package (26) and the housing sealing support portion (65) and including: (i) a housing sealing portion secured to the housing sealing support (65); and (ii) a sealing portion of the media pack (26) circumscribing the media pack (26) and sealing the preform (60) directly into the media pack (26); the sealing portion of the media package (26) being integral with the sealing portion of the housing. Air filter cartridge (22) according to claim 1, characterized in that: (a) the housing seal holder (65) includes a plurality of seal flow openings therein; and (b) the sealing material extends through the sealing flow openings. Air filter cartridge (22) according to either of Claims 1 and 2, characterized in that: (a) the z-filter media package (26) is a media package (26) z-coil filter. Air filter cartridge (22) according to claim 3, characterized in that: (a) the preform (60) has a first end comprising: (i) a sealing support portion the housing (65) directed radially outwardly; and (ii) a sidewall part; and (iii) a funnel transition portion between the sidewall portion and the sealing support portion of the housing (65) directed radially outwardly; and (b) the sealing portion of the media package (26) of the housing sealing arrangement includes sealing material between the funnel transition portion and the media package (26). Air filter cartridge (22) according to claim 4, characterized in that: (a) the sealing portion of the housing comprises an axial handle seal. Air filter cartridge (22) according to claim 5, characterized in that: (a) the housing sealing portion includes housing engaging sealing regions on opposite sides of the sealing support portion housing (65) directed radially out of the preform (60). Air filter cartridge (22) according to claim 6, characterized in that: (a) the z-filter media package (26) has first and second opposite flow faces; (b) the housing sealing surface of the housing sealing portion is positioned spaced from the first flow face at a distance no greater than 15 mm; (c) the housing sealing arrangement includes an integral edge sealing portion extending from the housing sealing portion to an end of the means package (26) adjacent the first flow face. Air filter cartridge (22) according to claim 7, characterized in that: (a) the funnel transition portion of the preform (60) extends at an angle to the package of medium (26) in the range of 30 ° to 60 °. Air filter cartridge (22) according to any one of claims 1 - 8, characterized in that: (a) the preform (60) has a second end opposite the first end; and (b) the second end of the preform (60) includes grid mechanism extending therethrough; (i) the grid mechanism also extends through the second flow face of the media pack (26). Air filter cartridge (22) according to claim 9, characterized in that it includes: (a) a central core element attached to the grading mechanism and extending into the media package ( 26). Air filter cartridge (22) according to claim 10, characterized in that: (a) the central core includes a hollow receiving section that projects into the media package (26) at a 30% distance from an axial length of the middle pack (26). Air filter cartridge (22) according to claim 11, characterized in that: (a) the hollow receiving section of the central core has an external aspect ratio of at least 5: 1; and (b) the hollow core receiving section includes a divider therein. Air filter cartridge (22) according to claim 12, characterized in that: (a) the central core includes a non-hollow central blade attached to the hollow receiving section of the central core and protruding from the central core. inside of the middle pack (26). Air filter cartridge (22) according to claim 13, characterized in that: (a) the non-hollow central blade has a generally triangular outer perimeter shape. Air filter cartridge (22) according to Claim 14, characterized in that: (a) the shape of the generally triangular outer perimeter of the non-hollow central blade has an apex that is displaced from the longitudinal geometric axis of the preform (60). Air filter cartridge (22) according to any one of claims 14 and 15, characterized in that: (a) the medium package (26) has a shape of two semicircles connected by parallel lines; and (b) the media pack (26) has a sealed center enclosed by a winding drop adjacent the first flow face. Air filter cartridge (22) according to Claim 16, characterized in that: (a) the preform (60) is a molded part including integrally: the sealing support portion of the housing (65), the sidewall portion, the funnel transition portion, the grid mechanism and the central core. Air filter cartridge (22) according to claim 17, characterized in that: (a) the media pack (26) has an axial length of at least 140 mm; (b) the media pack (26) has a larger transverse sectional axis of at least 190 mm, and a smaller transverse sectional axis of at least 110 mm. The method of making an air filter cartridge according to claim 1, characterized in that the method includes the steps of: (a) positioning the preform (60) and the media pack (26) of z-filter 26 in a mold with a preform portion (60) circumscribing the media pack (26); and (b) molding a housing seal resin material into the preform (60) with an integral part of the housing seal material by sealing the preform (60) in the middle package (26) completely around the package. of medium (26). A method according to claim 19, characterized in that: (a) the housing sealing resin material comprises polyurethane; and (b) the preform (60) includes the housing seal support portion (65) having openings therein through which the housing seal resin material flows during molding to provide mechanical locking.