Abstract:
A filter element and/or filter assembly such as for engine air filtration is provided that may comprise a filter housing, a pre-cleaner or cover, a primary filter element and optionally a secondary filter element. Different components may share a common seal to seal against unfiltered airflow. For example the secondary filter and the primary filter may use the same seal that may be carried by the primary filter. The secondary filter may also surround the primary filter.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 62/260,875, filed Nov. 30, 2015, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention generally relates to filter elements and/or filter assemblies such as for engine air filtration that may comprise filter housings, precleaners, primary and/or secondary filter elements. 
       BACKGROUND OF THE INVENTION 
       [0003]    Engine air filtration systems often comprise filter housings, precleaners, primary and/or secondary filter elements. Sometimes the secondary filter element may not be employed and/or a precleaner may not be employed. 
         [0004]    The present invention pertains to various improvements relating to such various air filtration systems. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The present invention relates to filter elements and/or filter assemblies such as for engine air filtration that may comprise one or more of the following: a filter housing, a precleaner, a primary filter element and/or a secondary filter element. 
         [0006]    According to an embodiment of the present invention, an air filter element includes a filter media pack comprising filter media. The filter media pack has an inlet face and an outlet face. Fluid can flow from the inlet face to the outlet face by passing through the filter media to filter the fluid. The air filter element also includes a gasket arranged in surrounding relation of one of the inlet face and the outlet face. The gasket extends about a perimeter of the filter media pack to form a complete ring. The gasket has first and second opposed end surfaces and an outer perimeter surface extending between the first and second opposed end surfaces. A receiving channel is recessed into the first end surface of the gasket in surrounding relation of the filter media pack. 
         [0007]    According to a more particular embodiment, the receiving channel is formed by seal material of the gasket and the receiving channel is surrounded by a continuous rib formed by the seal material. 
         [0008]    According to a more particular embodiment, the gasket is at least partially raised above the inlet face and the seal material is integrally molded to the filter media pack to secure and seal the gasket to the filter media pack and prevent leakage of unfiltered fluid flow therebetween. 
         [0009]    In a more particular embodiment, the air filter element is a panel filter, with the filter media pack being pleated with a plurality of pleat tips at the inlet face and a plurality of pleat tips at the outlet face. 
         [0010]    In a more particular embodiment, a screen member extends across the inlet face and is embedded in the seal material of the gasket. 
         [0011]    In a more particular embodiment, the air filter element is incorporated into a filter assembly that further comprises a secondary filter element comprising a casing. The casing includes a casing body surrounding the filter media pack and extending between the inlet face and the outlet face. The casing includes a flange projecting radially outwardly from the casing body. The flange is received in the receiving channel and a sealed position in the receiving channel whereby a continuous seal surrounding the filter media pack is formed between the projecting flange and the gasket. The secondary filter further comprises a filter member (screen or other filter) carried by the casing body and extending over the outlet face of the filter media pack. 
         [0012]    In a more particular embodiment, the filter member comprises a planar mesh screen material, and the filter media comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. 
         [0013]    In a more particular embodiment, the air filter element and the secondary filter element are both quadrilateral. 
         [0014]    In a more particular embodiment, the air filter element and the secondary filter element have at least one variable dimension that is either a depth dimension that varies from the inlet face to the outlet, or a width or length dimension that varies between opposed sides of the quadrilateral. 
         [0015]    In a more particular embodiment, the secondary filter element is gasket free and utilizes only the gasket of the air filter element. 
         [0016]    According to another embodiment of the present invention, a filter element comprises a casing that includes a casing body extending from a first end to a second end and having a hollow interior defining a cavity for receiving another filter element. The filter element further comprises a filter member carried by the casing body at the second end and over the cavity, such that fluid cannot flow from the cavity through the second end without passing through the filter member. 
         [0017]    In a more particular embodiment, the filter member comprises a planar mesh screen material. 
         [0018]    In a more particular embodiment, the casing is formed of plastic material. The plastic material can be integrally molded to planar mesh screen material and thereby permanently secures the planar mesh screen material to the casing. 
         [0019]    In a more particular embodiment, the filter element is incorporated into a filter assembly that further comprises an air filter installed into the cavity and sealingly engaged at a periphery to the casing. 
         [0020]    In a more particular embodiment of such a filter assembly, the filter assembly includes a gasket that seals between the filter element and the air filter. 
         [0021]    The gasket may have a quadrilateral shape and if so can engage a quadrilateral flange of the filter element. 
         [0022]    In a more particular embodiment, the gasket can be integrally provided by the air filter. 
         [0023]    In a more particular embodiment, such an assembly can comprise a filter housing defining a housing cavity comprising an outlet port and an inlet opening. The air filter can be a primary filter element that is received in the filter housing through the inlet opening. The primary filter element comprises filter media that comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. The filter element can be a secondary filter element for downstream use with the primary filter element. Further the assembly comprises a gasket member sealing simultaneously between the filter housing, the primary filter element, and the secondary filter element. 
         [0024]    In a more particular embodiment of an assembly, the gasket is integrally provided by the primary filter element and defines a channel receiving a flange of the secondary filter element. 
         [0025]    In an embodiment where the gasket is provided by the air filter, the gasket may integrally molded to the filter media. 
         [0026]    Preferably in an more particular embodiment, the primary filter element or air filter comprises a pleated filter media pack. 
         [0027]    In a more particular embodiment, such an assembly can further comprise a precleaner having an inlet port. The precleaner has at least an air cleaning device that utilizes air flow to separate larger particles prior to reaching the primary filter element. The precleaner can be mounted to the filter housing and can enclose the primary filter element and the secondary filter element therein. 
         [0028]    According to another embodiment of the present invention, a filter assembly comprises a filter housing defining a housing cavity comprising an outlet port and an inlet opening. The filter assembly further comprises a primary filter element received in the filter housing through the inlet opening. The primary filter element comprising filter media that comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. The filter element further comprises a secondary filter element. The secondary filter element includes a casing that includes a casing body extending from a first end to a second end and having a hollow interior defining a cavity receiving the primary filter element. A filter member is carried by the casing body at the second end and over the cavity downstream of the primary filter element, such that fluid cannot flow from the cavity through the second end without passing through the filter member. The filter assembly further comprises a precleaner having an inlet port. The precleaner has at least an air cleaning device that utilizes air flow to separate larger particles prior to reaching the primary filter element, and is mounted to the filter housing and encloses the primary filter element and the secondary filter element therein. The filter element further comprises a gasket member sealing simultaneously between the filter housing, the primary filter element, the secondary filter element and the precleaner. 
         [0029]    In a more particular embodiment, the gasket member is a single gasket member permanently attached to the primary filter element. 
         [0030]    In a more particular embodiment, the filter housing, the primary filter element, the secondary filter element and the precleaner all have a quadrilateral shape. The filter housing defines a quadrilateral body wall surrounding the primary filter element and the secondary filter element, and an end wall defining the outlet port enclosing a first end of the quadrilateral body wall. The filter housing includes at a second end of the quadrilateral body wall a quadrilateral step comprising a planar ledge and a surrounding containment wall, and the single gasket member extends outward from the filter media and is seated on the quadrilateral step. 
         [0031]    In a more particular embodiment, the precleaner has an axially extending quadrilateral flange facing the quadrilateral step and engaging the gasket member. 
         [0032]    In a more particular embodiment, manually actuated latches removably secure the precleaner and the filter housing. 
         [0033]    According to another embodiment of the present invention, a filter assembly comprises a filter housing defining a housing cavity, an outlet port and an inlet opening. The filter housing has a seating surface surrounding the housing cavity. The assembly further comprises a primary filter element received in the housing cavity and into the filter housing through the inlet opening along an install axis. The primary filter element comprises filter media that comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. The primary filter element has filter media extending between an inlet face and an outlet face, and a filter media depth along the install axis that is not constant and which extends between the inlet face and the outlet face. The filter media depth is shallower proximate the outlet port and deeper as the filter media transitions away from the outlet port. 
         [0034]    In a more particular embodiment, the air filter element is a panel filter. The filter media pack is pleated with a plurality of pleat tips at the inlet face and a plurality of pleat tips at the outlet face. The pleat tips at the inlet face form a plane, and the pleat tips at the outlet face are stepped to form an incline relative to the plane at the inlet face. 
         [0035]    In a more particular embodiment, the incline is at least 5 degrees relative to the plane at the inlet face, and the pleat tips are stepped at the outlet face to form said incline. 
         [0036]    In a more particular embodiment, the filter housing, the primary filter element, the secondary filter element and the precleaner all have a quadrilateral shape. The filter housing defines a quadrilateral body wall surrounding the primary filter element and the secondary filter element, and an end wall defining the outlet port enclosing a first end of the quadrilateral body wall. The filter housing includes at a second end of the quadrilateral body wall a quadrilateral step comprising a planar ledge and a surrounding containment wall. The primary filter cartridge is sealed against the planar ledge by a gasket. The containment wall defines a terminating edge that lies in a plane that is inclined relative to the planar ledge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    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: 
           [0038]      FIG. 1  is a perspective illustration of a filter assembly comprising a filter housing, a primary filter element, a secondary filter element and a precleaner; with a precleaner being shown delatched from the filter housing and the primary and secondary filter installed with the filter housing according to a first embodiment of the present invention; 
           [0039]      FIG. 2  is a perspective illustration of parts of the embodiment shown in  FIG. 1  illustrating the filter housing with the secondary filter element removed therefrom and the primary filter element partially extending from the secondary filter element; 
           [0040]      FIG. 3  is a perspective view of the secondary filter shown in the embodiment of  FIGS. 1-2  with the secondary filter including an end of the casing that is integrally molded to and with a cleaner screen member; 
           [0041]      FIG. 4  is an enlarged perspective view of a portion of the primary filter element and the secondary filter element shown in the embodiment of  FIGS. 1-3  to show how the secondary filter element is received within a channel of the primary filter element; 
           [0042]      FIGS. 5-8  are exploded assembly isometric views of a filter housing, precleaner and secondary filter element similar in many respects to that of the first embodiment as will be readily understood to one of ordinary skill in the art; 
           [0043]      FIGS. 9-12  are four different side end views of the embodiment and assemblies shown in  FIGS. 5-8  taken from four different side views; 
       
    
    
       [0044]    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 
       [0045]    Turning to  FIGS. 1-4 , an engine filtration assembly  10  is illustrated which includes a filter housing  12 , a primary filter element  14 , a secondary filter element  16  and a precleaner  18 . 
         [0046]    The filter housing  12  defines a housing cavity  20  that is sized to receive the primary filter element  14  and the secondary filter element  16 . Housing cavity  20  also comprises an outlet port  24  for conveying filtered air to an engine (or other such filtered air application) and an inlet opening  22  through with the primary filter element  14  and the secondary filter element  16  can be installed and removed when desired for replacement. The primary filter element  14  is received in filter housing through the inlet opening  22 , as is the secondary filter element  16 . 
         [0047]    The primary filter element  14  comprises filter media that comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. 
         [0048]    Typically the primary filter element  14  will have a filtration efficiency of at least 95% for removing 1 micron particles in some applications (or larger or smaller particles and higher efficiencies in other applications). 
         [0049]    The secondary filter element  16 , when employed, will typically remove larger particles and not smaller particles as will typically be removed by the primary filter element  14 . The secondary filter element  16  is used to avoid and limit clumps of dirt or large particles, leaves or other debris from entering into the outlet port  24  at the outlet end of the housing, such as when the primary filter element  14  is removed during service intervals or otherwise. As such, a planar screen member made of metal wire mesh or even plastic wire mesh with a defined pore size can be used as a surface or barrier filter. 
         [0050]    In an embodiment, the secondary filter element comprises a casing  26  including a casing body  28  extending from a first end  30  to a second end  32  and having a hollow interior defining a cavity  34  receiving the primary filter element  14 . A filter member  36  is carried by the casing body  28  at the second end  32  and over the hollow interior cavity  34  downstream of the primary filter element  14 , such that fluid cannot flow from the cavity  34  through the second end without passing through the filter member. 
         [0051]    The precleaner  18  has an inlet port  38  to receive raw unfiltered air flow from the external environment that is often laden with dust, debris and other particulates. The precleaner has at least an air cleaning device that utilizes air flow to separate out larger particles prior to reaching the primary filter element  14 . For example, the precleaner  18  may use centrifugal or change of direction cleaners such as shown in Lindstone, U.S. Pat. No. 4,218,223 entitled “precleaner for combustion engines” or utilize a bank of vortex separators such as in Dune, U.S. Pat. No. 4,746,340, entitled “Aircleaner Apparatus”, the entire disclosures of which are hereby incorporated by reference in their entireties. 
         [0052]    In an embodiment where a precleaner is used, the precleaner  18  is mounted to the filter housing  12  and encloses the primary filter element  14  and the secondary filter element  16  therein. 
         [0053]    In accordance with an inventive aspect, a gasket member  40  seals simultaneously between the filter housing  12 , the primary filter element  14 , the secondary filter element  16  and the precleaner  18 . 
         [0054]    With this sealing arrangement, unfiltered air flow passes first through the precleaner  18 , next through the primary filter element  14 , then through the secondary filter element  16 , whereby clean filtered air flow is received and ducted through the outlet port  24 . Preferably, gasket member  40  is carried by and more preferably permanently attached (e.g. such as by integrally molded or adhesively attached) to the primary filter element  14  such that the gasket is replaced fresh each time. 
         [0055]    Advantageously, the gasket member  40  may be a single gasket member permanently attached to the primary filter element  14  as illustrated. 
         [0056]    While other shapes are possible, the filter housing  12 , the primary filter element  14 , the secondary filter element  16  and the precleaner  18  all have a quadrilateral shape which may be rectangular or non-rectangular. The housings/bodys/casings for the filter housing, the secondary filter element and the precleaner may all be molded plastic material. 
         [0057]    With the quadrilateral shape, the filter housing  12  defines an quadrilateral body wall  42  surrounding the primary filter element  14  and the secondary filter element  16 , and an end wall  44  (opposite of inlet opening  22 ) defining the outlet port  24  enclosing a first end of the quadrilateral body wall  42 . The filter housing  12  may include at a second end of the quadrilateral body wall  42  a quadrilateral step  46 . The step  46  can comprise a planar ledge  48  and a surrounding seal containment wall  50 . In use, the single gasket member  40  extends outward from the filter media of the primary filter element  14  and is seated on the quadrilateral step  46  (either by an axial seal engagement with the ledge  48  or a radial seal engagement with the wall  50 , or both; compression of the seal member  40  may also cause bulging of the seal member to create a radial seal). 
         [0058]    When used with a precleaner or cover, the precleaner or cover has an axially extending quadrilateral seal engagement flange  52  facing the quadrilateral step  46  and engaging the gasket member  40 . 
         [0059]    To provide for ready servicing by a mechanic, the assembly further comprises manually actuated latches  54  removably securing the precleaner  18  and the filter housing  12  to allow for replacement of the primary filter element  14  (and optionally the secondary filter element) when desired and/or at regular service intervals. When serviced, the secondary filter element  16  may stay situated and in place while the primary filter is removed. The secondary filter element  16  can then be manually inspected and while installed helps prevent debris or dust created by the mechanic from entering the outlet port  24 . 
         [0060]    Another feature can be provided by virtue of a canted installation and/or canted shape to the primary and/or secondary filter elements. 
         [0061]    The primary filter element  14  has filter media  56  extending between an inlet face  58  and an outlet face  60  with a filter media depth along the install axis that is not constant and that extends between the inlet face and the outlet face. To provide greater air flow near the outlet port and not create restriction, the filter media depth can be shallower proximate the outlet port  24  and deeper as the filter media  56  transitions away from the outlet port  24 , in the installed position. 
         [0062]    Preferably, the primary filter element  14  is a panel filter as shown, the filter media being in a pleated filter media pack  62  with a plurality of pleat tips  64  at the inlet face  58  and a plurality of pleat tips  64  at the outlet face  60 . The pleat tips at the inlet face may form a plane in a typical arrangement. To provide for variable depth, the pleat tips  64  at the outlet face  60  can be stepped to form an incline relative to the plane at the inlet face  58 . 
         [0063]    These types of variable dimension filter media packs are shown for example in Tate et al, U.S. Application Ser. No. 62/243,740, entitled Filter Media Packs, Methods of Making and Filter Media Presses, the entire disclosure of which is hereby incorporated by reference. This shows that one or more dimensions of depth, width and length can be varied to achieve advantage. 
         [0064]    In some embodiments, the incline of the outlet face is at least 3 degrees and preferably at least 5 degrees relative to the plane at the inlet face, and wherein the pleat tips are stepped at the outlet face to form said incline. 
         [0065]    Another feature may be directed to inclined installation. The filter housing  12  includes at the quadrilateral step  46 , the planar ledge  48  and the surrounding seal containment wall  50 . With the primary filter cartridge being sealed against the planar ledge by the gasket, the containment wall  50 , as shown, can define a terminating edge  66  (e.g. facing the precleaner  18  or cover) that lies in a plane that is inclined relative to the planar ledge  48 . 
         [0066]    The primary filter element  14  and/or gasket member  40  as illustrated also provides inventive features. The gasket member  40  is arranged in surrounding relation of one of the inlet face  58  and the outlet face  60  (and preferably and in this instance the inlet face  58 ). The gasket member  40  extends about a perimeter of the filter media pack  62  to form a complete ring. 
         [0067]    The gasket member  40  has first and second opposed end surfaces  68 ,  70  that may be flat top and bottom surfaces, and an outer perimeter surface  72  extending between the first and second opposed end surfaces  68 ,  70 . 
         [0068]    Further, the gasket member  40  may include a receiving channel  74  recessed into the first end surface  70  (such as the bottom surface or surface opposite of the inlet face) of the gasket member  40  and in surrounding relation of the filter media pack  62 . 
         [0069]    Preferably, the recessed channel is formed by seal material of the gasket member  40  with the recessed channel  74  being surrounded by a continuous rib  76  also formed by the seal material. 
         [0070]    The rib  76  has a flat bottom wall and the recessed channel  74  has a flat bottom wall in an embodiment, with the rib  76  and channel bottom connect by an axially extending wall (e.g. that may be vertical). 
         [0071]    As shown, the gasket member  40  can be at least partially raised above the inlet face  58 . Preferably, the seal material of seal member  40  is integrally molded to the filter media  56  to secure and seal the gasket to the filter media pack and preventing leakage of unfiltered fluid flow therebetween. 
         [0072]    Additionally, the filter element  14  may include a screen member  78  extending across the inlet face and embedded in the seal material of the gasket member  40 . The screen member  78  may be expanded wire mesh and larger mesh than that provided by the screen member of the secondary filter element  16 . 
         [0073]    Screen member  78  can add support to the pleated filter media pack  62  and also serve to intercept large objects such as leaves or other debris to attempt to avoid impact or damage to the pleated filter media pack  62 . Additionally and contrary to many panel filters, this arrangement may provide the screen member  78  at the inlet face  58  and not the outlet. The outlet face  60  can be supported by the secondary filter element  16  if desired, or alternatively when embossed and made according to the aforementioned Tate et al, U.S. Application Ser. No. 62/243,740, has embossments that maintain pleat spacing to prevent blinding off. 
         [0074]    A further feature and aspect pertains to the secondary filter element  16 . The secondary filter element  16  comprises a casing  26 , the casing including a casing body  28  surrounding the filter media pack  62  and extending between the inlet face and the outlet face  58 ,  60  as generally illustrated or can be inferred from the drawings. 
         [0075]    The casing  26  is shown to include a flange  80  projecting radially outwardly from the casing body  28 , the flange  80  received and having a sealing engaged position in the receiving channel  74  whereby a continuous seal surrounding the filter media pack is formed between projecting flange  80  and gasket member  40 . 
         [0076]    The filter member  36  of the secondary filter element  16  may be a filter screen member carried by the casing body  28  and extending over the outlet face of the primary filter element. 
         [0077]    Preferably, the filter member  36  comprises a planar mesh screen material, in contrast to the filter media of the primary filter element that typically comprises a non-woven fibrous media comprising at least one of glass, cellulose or polymer material. 
         [0078]    As alluded to above, the primary air filter element and the secondary filter  16  element can have at least one variable dimension that is either depth dimension that varies from the inlet face to the outlet, or a width or length dimension that varies between opposed sides of the quadrilateral. 
         [0079]    An advantage in the present embodiment is that the secondary filter element  16  can be gasket free and utilizes only the gasket member  40  of the primary air filter element  14 . As such, the secondary filter element  16  can be reused while a fresh seal supplied by the primary may be realized during primary filter element  14  replacement. 
         [0080]    Further, the arrangement of the secondary filter element  16  surrounding the primary filter element  14  is a feature. The casing  26  includes the casing body  28  extending from a first end to a second end and having a hollow interior defining a cavity  34  for receiving another filter element such as the primary filter element  14 . At the same time, the casing body  28  carries the filter member  36  at the second end and over the cavity  34 , such that fluid cannot flow from the cavity through the second end without passing through the filter member  36 . 
         [0081]    As noted, the filter member  36  preferably comprises a planar mesh screen material, which is planar (and not pleated as per the primary filter element  14 ). 
         [0082]    Further, with the casing  26  being formed of plastic material in an embodiment, casing plastic material can be integrally molded to the planar mesh screen material of filter member  36  as shown and thereby permanently securing the planar mesh screen material to the casing. 
         [0083]    With this arrangement, the primary filter element  14  can be installed into the cavity  34  and sealing engaged at a periphery to the casing  26 . 
         [0084]    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. 
         [0085]    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. 
         [0086]    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.