Abstract:
A fluid filter apparatus comprising an upper housing shell; a lower housing shell; a pleat pack element comprising a peripheral frame and a folded pleated media. The frame is at least partially molded over the media to secure the media in the frame, and the media comprises two or more types of media of different densities from each other. A flow control element is disposed for changing the proportion of flow between the first media and the second media responsive to changes in at least one of temperature, pressure, flow rate and/or viscosity of the fluid.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part (CIP) of, and claims priority to U.S. patent application Ser. No. 13/755,134, filed Jan. 31, 2013 and pending, published as US 2014/0209528 A1, the entire disclosure of which is hereby incorporated by reference in its entirety. 
         [0002]    This application is also a continuation-in-part (CIP) of, and claims priority to U.S. patent application Ser. No. 13/755,154, filed Jan. 31, 2013 and pending, published as US 2014/0209529 A1, the entire disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0003]    The invention relates generally to the field of filtration. More specifically, some embodiments of the invention relate to filters that are used to filter liquids such as engine oil or transmission oil in engines such as vehicle engines. 
         [0004]    Various filtration devices are known. More specifically, filtration devices are known that are used in engine and/or vehicle applications, for example in the filtration of automotive transmission fluid. Some devices provide a housing forming a chamber containing a filtration media such as, for example, a felt type media that is permeable to the fluid but traps particles or other contaminants. A disadvantage to some of these filters is that they employ only one type of media, which in certain circumstances can cause difficulty of the fluid flow when the fluid is cold because the fluid tends to be highly viscous and not pass through the filtration media in the same fashion as is desired when the fluid is warm. Another disadvantage of some transmission filters is that the surface area of a flat sheet of media is less than may be desired within a compact housing shape. Yet another disadvantage of certain types of filters is that they may employ the filter media being mounted by being crimped directly between upper and lower housings in order to ensure a sufficient seal around the periphery between the two housings and also with the filter media. 
         [0005]    Accordingly, it would be desirable to have a filter device and method that can overcome any or some of the above-mentioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0006]    In light of the present need for filters such as transmission filters, a brief summary of various exemplary embodiments is presented. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the various exemplary embodiments, but not to limit the scope of the invention. Detailed descriptions of a preferred exemplary embodiment adequate to allow those of ordinary skill in the art to make and use the inventive concepts will follow in later sections. 
         [0007]    In some aspects, a fluid filter apparatus comprises: an upper housing shell; a lower housing shell; a pleat pack element comprising a peripheral frame and a folded pleated media, wherein the frame is at least partially molded over at least some edges the media to secure the media in the frame, wherein the media comprises two types of media of different filtration densities from each other. A flow control element is disposed for changing the proportion of flow between the first media and the second media responsive to changes in at least one of temperature, pressure, flow rate, and/or viscosity of the fluid. 
         [0008]    The foregoing objects and advantages of the invention are illustrative of those that can be achieved by the various exemplary embodiments and are not intended to be exhaustive or limiting of the possible advantages which can be realized. Thus, these and other objects and advantages of the various exemplary embodiments will be apparent from the description herein or can be learned from practicing the various exemplary embodiments, both as embodied herein or as modified in view of any variation that may be apparent to those skilled in the art. Accordingly, the present invention resides in the novel methods, arrangements, combinations, and improvements herein shown and described in various exemplary embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In order to better understand various exemplary embodiments, reference is made to the accompanying drawings, wherein: 
           [0010]      FIG. 1  is an exploded view of a filter according to a first preferred embodiment. 
           [0011]      FIG. 2  is a top view of the filter pack of  FIG. 1 . 
           [0012]      FIG. 3  is a cross-sectional view of the filter of  FIG. 1 . 
           [0013]      FIG. 4  is an exploded view of a filter according to a second preferred embodiment. 
           [0014]      FIG. 5  is a top view of the filter pack of  FIG. 4 . 
           [0015]      FIG. 6  is a cross-sectional view of the filter of  FIG. 4 . 
           [0016]      FIG. 7  is another cross-sectional view of the filter of  FIG. 4 . 
           [0017]      FIG. 8  is an exploded view of a filter according to a third preferred embodiment. 
           [0018]      FIG. 9  is a top view of the filter pack of  FIG. 8   
           [0019]      FIG. 10  is a cross-sectional view of the filter of  FIG. 8 . 
           [0020]      FIG. 11  is another cross-sectional view of the filter of  FIG. 8 . 
           [0021]      FIG. 12  is an exploded view of a filter according to a fourth preferred embodiment. 
           [0022]      FIG. 13  is a cross-sectional view of the filter of  FIG. 12 . 
           [0023]      FIG. 14  is a cross-sectional view of a filter according to a fifth preferred embodiment. 
           [0024]      FIG. 15  is another cross-sectional view of the filter of  FIG. 14 . 
           [0025]      FIG. 16  is a bottom view of the filter of  FIG. 14 . 
           [0026]      FIG. 17  is a view of a pleat pack used in the filter of  FIG. 14 . 
           [0027]      FIG. 18  is an exploded view of the filter of  FIG. 14 . 
           [0028]      FIG. 19  is another cross sectional view of the filter of  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    Some embodiments of the present invention relate to filters, such as automotive transmission fluid filters. Some embodiments will now be described with reference to the drawing figures in which like numbers generally designate like parts throughout. 
         [0030]      FIG. 1  is an exploded view of a filter according to a first preferred embodiment.  FIG. 2  is a top view of the filter pack of  FIG. 1 .  FIG. 3  is a cross-sectional view of the filter of  FIG. 1 . 
         [0031]    A filter  10  includes a lower cover  12  having a fluid inlet opening  14 . An upper cover  15  is provided. A filter pack  16  has a pleated first media  18  and a pleated second media  20 . The media are separated by a flow control element  22 . The flow control element  22  determines (along with the types and surface area of media as described below) the amount of fluid that will flow through each of the various media sections, as a function of temperature, viscosity and/or fluid pressure as described in more detail below. In this example the element  22  is passive, it is rigid and does not change configuration based on fluid pressure differential of fluid flowing through the filter  10 ; yet the small gaps for fluid it provides do control the ratio of fluid flow through the first media  18  and second media  20 . In this example the element  22  (which may also be considered as a flow-restriction plate) is a vertical wall or web with one oe more controlled sized permanent holes  23  as seen best in  FIG. 3 . The first media  18  and second media  20  can be any of a wide range of materials suitable for filtering the fluid such as for example vehicle transmission fluid. The media  18  and  20  can have different characteristics from each other such as for example density, efficiency and/or material type. The filter pack  16  has a surrounding housing portion  24  and transverse ribs  26 , which may be integral with the housing portion  24 . The media  18  and  20  can have the housing  24  and ribs  26  over-molded onto the media. 
         [0032]    The housing  24  can be attached to the lower cover  12  and the upper cover  15  by one or more of vibration welding, laser welding, bonding, ultrasonic welding or infrared welding. The housing  24  can also have mounting bosses  30  and  32  for attachment of the filter  10  to a device such as a vehicle transmission. In this embodiment the lower cover  12  and upper cover  15  form a chamber that encloses the media types. The fluid outlet  44  is part of the housing  24 . However, in other embodiments the fluid outlet  44  may be provided as an opening in the upper cover  15 . Also, in other embodiments the lower cover  12  and upper cover  15  may be attached to each other and completely surround the pleat pack. The selection of the size, shape and total surface area of the holes in the element  22  affect the ratio of fluid flow between the two media. The selection of surface area of each media  18  and  20  will also be a factor in the relative flow amounts through each media in all embodiments. The top shell  15  may have stiffening and spacing dimples  42 . The dimples  42  may also be arranged to correspond to bolt heads in the surrounding transmission components, this allowing a more compact mounting of the filter  10  adjacent the surrounding components. The housing  24  of the pack  16  also incorporates the fluid outlet  44 . The top shell  15  and bottom shell  12  are attached, respectively, to the top and bottom of the housing portion  24  by suitable attachment, such as by one or more of vibration welding, laser welding, bonding, ultrasonic welding or infrared welding. 
         [0033]      FIG. 4  is an exploded view of a filter according to a second preferred embodiment,  100 .  FIG. 5  is a top view of the filter pack of  FIG. 4 .  FIG. 6  is a cross-sectional view of the filter of  FIG. 4 .  FIG. 7  is another cross-sectional view of the filter of  FIG. 4 . In this embodiment, like parts are labeled the same as in the first embodiment and are similar to those of the first embodiment. In this embodiment the “flow control element” is a flow restriction plate that is also passive, or immovable, similar to the element  22  of the first embodiment. The flow control element is integrated with a particular stiffening rib  128 . The rib  128  has passive flow control apertures  131 . The flow control apertures  131  can be slots or gaps in a the rib  128 , which may be for example in the shape of a comb having upwardly projecting fingers  129  that may contact the underside of the upper shell  40 . Aside from the fingers  129 , fluid can flow over the top of the rib  128 , i.e. through apertures  131 . In this way the fingers partially define a gap for fluid, which gap is also partially defined by the inner surface of the top shell  40 . The amount of flow will depend on the viscosity of the fluid, and be greater with low temperature, high viscosity, fluid in cases where the media  20  is coarser or less efficient than the media  18 . Selection of the area of the flow control apertures  131  as defined between the fingers  129  (their width and number) allows a selection of the degree of flow balance between the first media  18  and the second media  20 . 
         [0034]      FIG. 8  is an exploded view of a filter according to a third preferred embodiment,  200 .  FIG. 9  is a top view of the filter pack of  FIG. 8 .  FIG. 10  is a cross-sectional view of the filter of  FIG. 8 .  FIG. 11  is another cross-sectional view of the filter of  FIG. 8 . In this embodiment, like parts are labeled the same as in the first embodiment and are similar to those of the first embodiment. However, in this embodiment the “flow control element” is a valve  222  that is semi-active in that its upper regions flex or move by deflecting. In this embodiment, the valve  222  is a resilient flexible member which may be elastomeric. The valve  222  may be an elastomeric component with an internal stiffening insert of steel that is overmolded onto the elastomeric material. As seen in  FIGS. 10 and 11 , the valve can a have lower lobe  224  that seals in a groove in the mounting location  226  of the housing  24 . The amount of flow will depend on the viscosity of the fluid, and be greater with low temperature, high viscosity, fluid in cases where the media  20  is coarser or less efficient that the media  18 . The flow balance between the first media  18  and the second media  20  is affected by factors such as the stiffness of the material of the valve  222 , the cross section shape of the valve  222 , and the temperature of the fluid. 
         [0035]      FIG. 12  is an exploded view of a filter according to a fourth preferred embodiment,  300 .  FIG. 13  is a cross-sectional view of the filter of  FIG. 12 . The filter  300  has a lower shell  312  and an upper shell  314 . The lower shell has a fluid inlet  316 , and the upper shell has a fluid outlet  318 . A pleat pack  322  has a surrounding housing  320  overmolded onto a media region  324 . The media region  324  may have one or more media types, either with or without a valve as described above. The lower shell  312 , upper shell  314  and pleat pack  320  are attached together as described above. The filter includes at least one other sheet type media, shown as  330  and  332 , which span the housing. In this example the sheet media  330  and  332  are located in the flow path before the pleated media  324 . The sheet media  330  and  332  may be of different characteristics from the pleated media  324 , and from each other. The sheet media  330  and  332  may also have holes or apertures  334 ,  336  therethrough, which form a bypass for fluid, and they may be of lower or higher density or efficiency than the pleated media region  324 . The apertures  334 ,  336  can be overlapping or non-overlapping. 
         [0036]      FIG. 14  is a cross-sectional view of a filter  400  according to a fifth preferred embodiment.  FIG. 15  is another cross-sectional view of the filter of  FIG. 14 .  FIG. 16  is a bottom view of the filter of  FIG. 14 .  FIG. 17  is a view of a pleat pack used in the filter of  FIG. 14 .  FIG. 18  is an exploded view of the filter of  FIG. 14 .  FIG. 19  is another cross sectional view of the filter of  FIG. 14 . The filter includes a lower cover  412  having an inlet  414  and an upper cover  415  having an outlet  444 . A pleat pack  416  has two media regions  418  and  420 . A rib of the pleat pack  416  has a projecting passive flow control element  422  in the form of a blade shape. The blade  422  projects downwardly and is complementary with a V-shaped trough region  417  of the lower cover  412 . Depending on the various flow control characteristics of the fluid, described above with respect to the other embodiments, the fluid entering the inlet will have a first flow path through the first media  418 , as best illustrated in  FIG. 19 . This first flow path is fluid that is essentially blocked by the blade  422 . A second flow path is formed where fluid flows around the sides of the blade  422  and thus passes around the blade and through the second media  420 . The ratio of relative volume through each flow path will vary based on geometry and size of the blade, and on the fluid characteristics described above with respect to the other embodiments, for example the relative media areas, and the relative pressure drops of the medias. 
         [0037]    It will be appreciated that some embodiments provide a filter system that provides control of the ratio or proportion of fluid that passes through a first media as compared to the ratio or proportion that passes through a second media. This control phenomenon may dynamically vary depending on factors such as for example, fluid supply flow rate and/or supply pressure and/or viscosity of the fluid and/or temperature of the fluid. Some embodiments provide types of active biased flow control element that deflect, and some other embodiments provide types of passive flow control elements in the form of apertures such as gaps, slots or circular or otherwise shaped holes in a flow control plate or other flow control structure. In some embodiments the flow control element is thermally activated in that change in temperature of fluid affects fluid viscosity which changes the proportion of fluid flow through the respective filter media. Alternatively, or in addition, the flow control element could change its shape, properties, or behavior with temperature, hence effecting flow properties through the media. 
         [0038]    From the above description and drawings, it will be appreciated that several embodiments are shown with various types of flow control element disposed in the flow path on the outlet side of the pleat pack, and one embodiment is shown with a type of flow control element on the inlet side. However, it will also be clear that any type of flow control element can be provided on either the inlet side and/or the outlet side flow path. That is, an active element and/or a passive element can be placed on either side of the pleat pack, either towards the inlet side or the outlet side. 
         [0039]    Although the various exemplary embodiments have been described in detail with particular reference to certain exemplary aspects thereof, it should be understood that the invention is capable of other embodiments and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be affected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only and do not in any way limit the invention, which is defined only by the claims.