Abstract:
A straight through flow filter element is provided in which the seal and/or seal support may be arranged to be generally flush with the flow face of the filter media pack. In some embodiments, long filter media packs may be facilitated. Additionally, certain processing advantages in simplicity of molding a seal on the support can be accomplished.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This patent application is a continuation of co-pending PCT/US2011/028491, filed Mar. 15, 2011, designating the United States, which claims the benefit of U.S. Provisional Patent Application No. 61/314,747, filed Mar. 17, 2010, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to fluid filters and more particularly to the sealing systems of such fluid filters and particular inline straight through flow filter media packs including fluted filter media packs. 
       BACKGROUND OF THE INVENTION 
       [0003]    Filters of the type used for filtering particulate matter from fluids sometimes include a filter housing having an inlet for receiving the fluid entrained with particulate matter and an outlet for delivering the filtered fluid to a device needing fluid that is free of particulate matter. For example, a filter may be provided at the air inlet of an engine, a cabin ventilation system, an air compressor, an HVAC system, and industrial air collection system or the like to remove dust or other particulate matter that could cause damage. 
         [0004]    In such filters, the particulate matter is typically removed by a filter element that is removably installed within the filter housing in such a manner that the fluid must flow first through a filter element. In some systems, the filter element is simply placed between upstream and downstream duct sections. In either case, the filter element may or may not include its own housing. In either case and over time, the filter pack of the filter element becomes plugged or coated with particulate matter, necessitating removal and replacement of the filter element in order for the filter to continue in its function of supplying particulate free fluid to the given application. 
         [0005]    There is also known in the art to use a variety of different filter packs included pleated filter packs and fluted filter packs, both of which can be configured as a straight through flow type filter pack. For example, a fluted filter media has opposed inlet and outlet flow faces and an outer peripheral surface extending between the inlet and outlet faces. The fluted filter media comprises multiple flutes extending between the inlet and outlet flow faces with alternating flutes being closed at either the inlet or outlet ends such that some flutes are open at the inlet face and closed at the outlet face while other flutes are open at the outlet face and closed at the inlet face. In this manner, fluid is forced to traverse through the filter media as the fluid flows from the inlet face to the outlet face. Examples of such fluted filter media arrangements and filter elements incorporating the same are shown, for example in U.S. Pat. No. 7,318,851 and Publication Nos. US/2007/0186528; 2007/0193236; and US/2006/0091061, all assigned to the present assignee, and all of which have disclosures which are hereby incorporated by reference in their entirety to the extent not inconsistent with the present disclosure. Details therein can be applicable or combined with the disclosed embodiments herein. 
         [0006]    Often times, in an existing application there is already an existing envelope in which a filter element must reside and sealed against. Accordingly, some filter element designs may be required to fit a given envelope size. Additionally, in some cases, it may be desirable for a given filter element to fit or seal against different housing or application arrangements. While various filter element and sealing system arrangements are known generally within the prior art, the present invention is directed toward various improvements. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    One aspect of the present invention is directed toward an improvement on a seal member and seal support ring arrangement for a straight through flow filter (where the fluid generally is not redirected) such as a fluted filter element or alternatively a pleated panel filter. The filter element comprises a fluted filter media having inlet and outlet flow faces on opposed ends thereof and an outer peripheral surface extending between opposed ends. The fluted filter media comprises a plurality of flutes extending between inlet and outlet flow faces with portions of flutes being closed such that fluid transfers through the filter media as fluid flows from the inlet flow face to the outlet flow face. A pre-formed seal support ring (which may be formed from such materials as plastic or metal) surrounds the outer peripheral surface. This ring has a terminating end surface that is generally flush with one of the inlet and outlet flow faces. This ring is also generally confined between the inlet and outlet flow faces such that the seal support ring does not extend over the inlet or outlet flow faces. Seal member is molded onto the seal support ring. 
         [0008]    Another aspect of the present invention is directed toward a method of making such a filter element. The method comprises forming a straight through flow filter such as a fluted filter media pack (or pleated pack) having inlet and outlet flow faces on opposed ends thereof and an outer peripheral surface extending between opposed ends. The fluted filter media comprises a plurality of flutes extending between the inlet and outlet flow faces with portions of the flutes being closed such that fluid transverses through the filter media as fluid flows from the inlet flow face to the outlet flow face. The method also comprises molding a seal member on a seal support ring such that the seal member is generally flush with the terminating end of the support ring; and arranging a filter media pack within the seal support ring such that the seal support ring extends over the outer peripheral surface until the terminating end of the support ring co-locates along a flat surface to be generally flush with one of the inlet and outlet flow faces. Additionally, the method contemplates affixing the seal support ring to the outer peripheral surface of the fluted filter media pack. 
         [0009]    It may be a subsidiary feature according to this methodology that the molding may be conducted prior to the arranging and the fixing may be conducted after the arranging and other sequences may be performed. 
         [0010]    A further aspect of the present invention is directed toward an improved arrangement between a seal and a straight through flow filter such as fluted filter element (or pleated filter pack) in which a seal may be molded onto a seal support ring, but yet may be arranged generally flush with one of the inlet and outlet flow faces of a fluted filter media. According to this aspect, a filter element comprises a fluted filter media similar to either of the aspects above. A pre-formed seal support ring surrounds the outer peripheral surface of the fluted filter media. A seal support ring may be generally confined between the inlet and outlet flow faces such that the seal support ring does not extend over either the inlet or outlet flow faces. The seal member is molded onto the support ring with the seal member having a terminating seal surface that is generally flush with one of the inlet and outlet flow faces. The seal member surrounds the outer peripheral surface of the fluted filter media. 
         [0011]    Seal members of the various concepts disclosed herein may be either of the type that are radial or axial seals or a combination thereof. 
         [0012]    Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0014]      FIG. 1  is an isometric and partially cut cross-sectional view of a filter element according to a first embodiment of the present invention; 
           [0015]      FIG. 2  is a cross-sectional view of the filter element shown in  FIG. 1 ; 
           [0016]      FIG. 3  is a cross section of a filter element and housing combination using the filter element of  FIG. 1 ; 
           [0017]      FIG. 4  a cross section of seal support ring and sealing mold for forming a seal on the seal support ring according to one embodiment of a method of forming the seal; 
           [0018]      FIG. 5  is an exploded assembly view in cross section of the filter element according to  FIG. 1 ; 
           [0019]      FIG. 6  is a cross section of a filter element similar to  FIG. 1  but according to another embodiment with a longer extended filter pack extending beyond the housing mount structure to provide increased filtration capacity; 
           [0020]      FIG. 7  is an isometric and partially cut cross-sectional view of a filter element according to another embodiment of the present invention; 
           [0021]      FIG. 8  is another isometric view of the filter element of  FIG. 7 , but taken from a different end perspective; and 
           [0022]      FIG. 9  is an isometric and partially cut cross-sectional view of a filter element according to yet another embodiment of the present invention. 
       
    
    
       [0023]    While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    The first embodiment is illustrated in  FIGS. 1-5 . As shown therein, an inline straight through flow type filter element such as a fluted filter element  10  can be mounted at least partially within a housing  12 . As shown, the housing  12  may be an existing housing for engines and as such has a given or fixed envelope size, a predetermined sealing interface, as well as a fixed mounting structure. As such, the filter element  10  is designed to utilize this given mounting structure, sealing interface, and pre-determined envelope. 
         [0025]    As shown in  FIG. 3 , the housing  12  includes an internal annular housing sealing surface  14  against which the filter element  10  may seal through compression of the seal material between the filter element and the housing. In this instance, the housing sealing surface  14  is such that the filter element  10  may form a radial seal therewith, but it may also or alternatively axially seal. As shown, the housing sealing surface  14  may also be disposed radially inward from the inner perimeter of the upper end or upper opening  16  of the housing  12  into which the filter element  10  may be installed and removed. Additionally, it can be seen that the housing  12  includes a corresponding mounting structure  18  with apertures  20  to facilitate fastening of the filter element  10  to the housing  12 . 
         [0026]    As shown, the filter element  10  includes a straight through flow filter media such as a fluted filter media pack  24 , although it is equally applicable to other such inline flow filters such as a pleated filter pack to include panel filters and the like, which may have various annular shapes, which herein is meant to be broad to include oval, racetrack, round, oblong and even rectangular in that it forms a continuous loop. The filter element  10  preferably employs fluted filter media which is known to provide increased capacity in a given envelope. 
         [0027]    In this regard and according to certain embodiments, fluted filter media pack  24  includes a base sheet  26  and a fluted sheet  28  secured together and wound about a winding core  30  to provide a plurality of flutes including inlet flutes  32  and outlet flutes  34  that extend between inlet and outlet flow faces  36 ,  38 . As shown, the inlet flutes are open at the inlet flow face  36  and closed at the outlet flow face; while the outlet flutes  34  are closed at the inlet flow face  36  and open at the outlet flow face  38 . In this manner, fluid entering the inlet flow face enters the inlet flow face and must traverse through the filter media (either the base sheet or the fluted sheet) as fluid flows from the inlet flow face to the outlet flow face. As a consequence of flowing through the filter media of either the fluted sheet or base sheet, particulate matter, such as dust and the like is thereby removed from the fluid stream. For example, dust or the like in an air flow stream will then be trapped in the filter media of either the base sheet or the fluted sheet. As shown in  FIG. 1 , the fluted filter media pack  24  may be generally circular, but other shapes for the first embodiment may be contemplated including such as the oval or race-track shape shown in another embodiment (see e.g.  FIGS. 7-8 ) in which other structures similarly associated with  FIG. 1  would take a similar shape. 
         [0028]    The filter element  10  additionally includes a pre-formed seal support ring that may be formed from such material as plastic (such as glass-filled nylon) or other such materials such as metal. The material of the support ring is therefore generally rigid as opposed to compressible or elastic (as in the case of the seal material). By pre-formed, it is meant that the support ring is not formed in place on the fluted filter media, but formed separately and apart therefrom and then attached such as by gluing or by such means as using a portion of the seal member itself to attach the support ring. 
         [0029]    As shown in the drawings, the support ring  40  surrounds the outer annular peripheral surface  42  of the fluted filter media pack  24 . The support ring  40  has a terminating end surface  44  that is generally flush (e.g. flush or almost flush) with one of the inlet and outlet flow faces  36 ,  38 . As also shown, the seal support ring is confined between the inlet and outlet flow faces and does not extend over either of the inlet or outlet flow faces. In this manner, the flow of fluid from the filter pack is unimpeded and does not impact upon the support ring. Additionally, there is material savings by confining the support ring to between the opposed outlet and inlet flow faces. Additionally, the fluted filter media pack can additionally be lengthened to take full advantage of the entire length of the overall housing, which in some cases may provide for increased media for the given envelope size. Thus, a longer fluted filter media pack  24  may be employed in some circumstances. 
         [0030]    Additionally, a seal member is molded onto the seal support ring  40 . The seal member  46  circumscribes and surrounds the support ring  40  and is positioned for engaging the housing sealing surface  14 . Seal member  46  is preferably formed from foamed urethane material, but may alternatively be formed from other rubber-like elastic materials such as Neoprene, gasketing material and the like. 
         [0031]    Preferably the seal member  46 , according to some embodiments, may be generally flush with the terminating end surface  44  of the support ring  40 . By “generally flush” it is meant that some deviation therefrom is permitted as it will be understood that such things as mold flash and the like would be permissible over the terminating end surface—and hence includes flush or almost flush. Likewise, the seal member  46  is generally flush or perhaps recessed slightly from one of the inlet and outlet flow faces. 
         [0032]    Another advantage of this design is that a mounting shell  48  may be located off of the support ring  40 . Mounting shell  48 , shown in this embodiment, also surrounds the outer periphery surface  42  of the fluted filter media pack  24  and includes an outward flange  50  with fasteners  52  that are adapted to interact with the mounting structure  18  and apertures  20  of the housing  12 . As shown, the mounting shell  48  can be located off of and secured to the pre-formed seal support ring  40  at an interface  54  at the outlet end of the fluted filter media pack  24 . 
         [0033]    This securement interface  54  preferably includes an enlarged guide-in on the support ring  40  with larger and smaller perimeter/diameter segments  57 ,  58  joined by a radially offset segment  59 . In this manner, the mounting shell  48  and sleeve portion  60  thereof may telescopically interfit within and inside of the larger segment  57 . A glue or adhesive bead such as made by urethane, bonding agent or the like at  62  thereby secures both of the mounting shell  48  and the support ring  40  together and along with the fluted filter media pack  24 . Preferably, the annular glue bead is laid along the inner surface of the seal support ring but may also be laid on the outer surface of the mounting shell  48 . 
         [0034]    Other interfitting arrangements, of course, are possible to include a situation where a portion of the mounting shell would extend over the outer perimeter of the support ring  40  and only be attached to the support ring with the support ring being independently secured to the fluted filter media pack. Such that other interfacing arrangements are contemplated and possible. 
         [0035]    As shown, the inlet flow face  36  may rest slightly below mounting location tabs extending from the mounting shell over the inlet flow face. However, more preferably as shown in the alternative embodiment of  FIG. 6 , the upper end  64  of the fluted filter media pack  24  extends above the mounting shell  48  to ensure maximum utilization of length and increasing filter media and filtration capacity. This also ensures that the location of the mounting shell is strictly by means of the location off of the support ring  40  as shown in this embodiment. As a consequence, the corresponding flange  50  is located precisely relative to the support ring  40  and seal member  46  thereby controlling without much intervening structure and axial distance therebetween. 
         [0036]    The methodology for molding the seal member and assembling the filter element is shown, for example, in  FIGS. 4-5 . Referring to therein, the fluted filter media pack is formed in a relatively conventional manner, such as by coiling up the fluted sheet and flat base sheet with opposed beads of seal material on either end. The seal is molded onto a seal support ring preferably prior to attachment to the filter media pack. The seal member is molded onto the support ring with a suitable mold  66  having an annular molding cavity  68  that permits the free rise of the urethane material used to form the seal member. As shown, the molding can be accomplished by first placing the seal support ring  40  (preferably without the filter media pack, although the filter media pack may also be pre-attached to the seal support ring) and placing the seal support ring within the annular molding cavity  68  of the mold  66 . Thereafter, the uncured urethane material is poured into the molding cavity  68 , in this case on the outside of the support ring  40  (but in alternative embodiments it could be on the internal surface of the support ring), such that the seal member  46  is allowed to form by free-rising through the urethane material to take the form of the molding cavity  68  and have a generally flush surface with the terminating end  44  of the support ring  40  as these two components are located or formed by the bottom surface of the molding cavity  68 . 
         [0037]    If the filter media pack is not pre-attached to the support ring, then the filter media pack is assembled by arrangement within the support ring. The guide end at  56  helps facilitate installation of the fluted filter media pack  24  for reception into the support ring  40 . A circular bead of adhesive such as glue, urethane or the like at  62  can then be received into the larger segment  57  as there is a natural cavity for reception of the same, which facilitates affixing the seal support ring to the outer peripheral surface of the fluted filter media pack at the outlet end of the media pack. Prior to curing of this adhesive  62 , the mounting shell  48  may then be telescopically received and secured into engagement with the adhesive  62  to locate the mounting shell and attach the mounting shell  48  to the support ring  40 . 
         [0038]    Turning to  FIGS. 7-8 , another alternative embodiment of a filter element  110  is illustrated sharing some similar aspects to that of the embodiment of  FIGS. 1-5  and therefore the above description is generally applicable to this embodiment with some of the more notable distinctions discussed below and with similar reference numbers being used (but with a  100  number series). This filter element  110  likewise includes a fluted filter media pack  124  (or other inline straight through flow filter media) but in this embodiment it has an oval shape wound about a winding core  130  in the form of a truss like frame structure. This embodiment is adapted to seal against a duct  112 , and in this case a radially inward seal in which urethane or other such seal material may compress radially outward. Further, in this embodiment the filter element may form part of the duct. 
         [0039]    The media pack  124  includes an inlet flow face  136  and an outlet flow face  138 . A seal support ring  140  supports a seal member  146  in which the terminating end face  146   a  thereof is generally flush with one of the flow faces—in this case outlet flow face  138 , similar to the first embodiment. However, in contrast to the embodiment of  FIG. 1 , and as shown in  FIGS. 7-8 , the terminating end surface  146  of the seal support ring  140  here may be substantially recessed from the outlet flow face  138  as shown; and further an annular gap  147  is formed between the inner peripheral sealing surface of the seal member  146  and the outer peripheral surface of the filter media pack  124  so to provide a region to receive a corresponding seal surface of a sealing rim of the duct. 
         [0040]    The seal support ring  140  is similarly connected to a mounting shell  148  that may interact and connect with upstream ductwork with a mounting profile and channel illustrated at the upstream end. An interface  154  between the ring  140 , outer periphery of the filter media pack  124  (and optionally the mounting shell  148 ) is sealed with an annular bead of sealing adhesive (such as urethane, glue or the like) to preclude unfiltered fluid from short-circuiting and traveling between the outside periphery of the fluted filter media and the inside of the seal support ring. Upstream thereof, preferably at least one breather port  174  and liquid drain is provided to provide pressure equalization or to allow for drainage. Air entering the port  174  must still go through the filter media pack  124  to get to the outlet flow face  138 . 
         [0041]    Turning to  FIG. 9 , another alternative embodiment of a filter element  210  is illustrated sharing some similar aspects to that of the embodiment of  FIGS. 1-5  and therefore the above description is generally applicable to this embodiment with some of the more notable distinctions discussed below and with similar reference numbers being used (but with a  200  number series). The media pack  224  which is a fluted media pack includes an inlet flow face  236  and an outlet flow face  238 . A seal support ring  240  supports a seal member  246  in which the terminating end face  246   a  thereof is generally flush with one of the flow faces—in this case the inlet flow face  236 , in contrast to the first embodiment. The terminating end surface  244  of the seal support ring  240  is also generally flush with the inlet flow face  236 . In this embodiment the mounting shell  248  takes the form of a border ring member that may be used on the outlet face  238  and to radially position the filter within a housing that may be similar in some respect to  FIG. 1 , except that it may be fully contained with a reusable cover of the housing. 
         [0042]    All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0043]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0044]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.