Abstract:
A filter cartridge configured as a filter-in-filter design with an inner filter and an outer filter. The filter cartridge has features, for example an overhanging lip, to engage with a lid of a filter housing in which the cartridge is installed such that the lid is connected to the cartridge. As a result, the cartridge can be connected to the lid to facilitate installation and removal of the cartridge. Alternatively, the same features that allow connection with the lid permit a user to manually grasp the cartridge during installation and removal so that the cartridge can be used without a lid having attachment features. The filter cartridge is also designed to enable use of a longer inner filter within the outer filter. A longer inner filter increases the amount of filter media available for filtering the fluid.

Description:
FIELD 
       [0001]    This disclosure generally pertains to the field of filtration, and more particularly to a filter cartridge for use in filtration systems, for example a fuel filtration system. 
       BACKGROUND 
       [0002]    Filter cartridges are used in a number of different technologies to filter a fluid. One example of a filter cartridge is a fuel filter cartridge used in a fuel filtration system. 
         [0003]    Filter cartridges can be constructed with a single filter media, or with multiple filter media, for example as a filter-in-filter design that uses an inner filter media disposed inside of an outer filter media. A filter-in-filter design can provide a high particle filtration efficiency and high fuel/water separation through a wide range of fuel interfacial values. 
       SUMMARY 
       [0004]    A filter cartridge for use in filtering fluids, for example fuel, lubrication, hydraulic and other liquids, as well as air. A number of different uses for the filter cartridge are possible. For example, in one embodiment, the filter cartridge can be used in a “no filter, no run” filtration system that verifies that the filter cartridge is present to safe-guard against damage to fuel injectors, associated fuel components, etc. and engine malfunctions. In such a filtration system, fuel flow to the engine is prevented altogether or permitted in an amount insufficient to allow engine operation if the filter cartridge is not installed, and an appropriately designed filter cartridge is required to be used in order to permit sufficient fuel flow for engine operation. 
         [0005]    In the embodiment described herein, the filter cartridge is a filter-in-filter design with an inner filter and an outer filter. The filter cartridge is designed with features to engage with a lid of a filter housing in which the cartridge is installed such that the lid is connected to the cartridge. As a result, the cartridge is connected to the lid to facilitate installation and removal of the cartridge. Alternatively, the same features that allow engagement with the lid permit a user to manually grasp the cartridge during installation and removal so that the cartridge can be used without a lid having attachment features. 
         [0006]    The filter cartridge is also designed to enable use of a longer inner filter within the outer filter. A longer inner filter increases the amount of filter media available for filtering the fluid. 
         [0007]    In one embodiment, the filter cartridge includes an outer filter having first filter media with an upper end and a bottom end, a first end plate connected to the upper end of the first filter media, and a second end plate connected to the bottom end of the first filter media, the outer filter including a central axis. The first end plate includes a generally circular, horizontal plate and a flange that extends downwardly from the plate. The plate and the flange defining an open area, and the plate has an edge that extends radially past the flange to define a lip. The lip permits connection to suitable features on the lid as well as allows manual grasping of the cartridge. The filter cartridge also includes an inner filter having second filter media with an upper end and a bottom end, a first end plate connected to the upper end of the second filter media, and a second end plate connected to the bottom end of the second filter media. The second filter media is disposed within the first filter media, and the first end plate of the inner filter and the upper end of the inner filter are disposed within the open area. 
         [0008]    The filter housing lid can include a plurality of resilient fingers that project downwardly therefrom at respective positions for engagement with the lip on the first end plate of the outer filter to enable connection of the lid to the outer filter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a sectional view of a filter assembly that includes a filter cartridge in a filter housing. 
           [0010]      FIG. 2  is a perspective view of the filter housing with the lid removed to show the interior of the housing. 
           [0011]      FIG. 3  is a detailed cross-sectional view of the filter cartridge. 
           [0012]      FIG. 4  is a cross-sectional view of the outer filter upper end plate. 
           [0013]      FIG. 5  is a perspective view of the inner filter upper end plate. 
           [0014]      FIGS. 6A and 6B  are perspective and side cross-sectional views, respectively, of the inner filter lower end plate. 
           [0015]      FIG. 7  is a cross-sectional view of the outer filter lower end plate. 
           [0016]      FIG. 8  is a close-up, detailed view showing a finger on the lid engaging the lip. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The disclosure in U.S. patent application Ser. No. 11/780,176, filed on Jul. 19, 2007, and entitled “Standpipe With Flow Restriction Valve, and Filter Cartridge”, is incorporated herein by reference in its entirety. 
         [0000]      FIG. 1  illustrates a filter assembly  10 , for example a fuel filter assembly, which is intended to filter a fluid, for example diesel fuel, and remove water from the fluid before the fluid reaches a protected system, for example a fuel injection pump and fuel injectors. This description will hereinafter describe the fluid as fuel. However, it is to be realized that the concepts described herein can be used for other fluids. In addition, in appropriate circumstances, the concepts described herein can be used to remove contaminants other than water from the fluid. And, in appropriate circumstances, one or more of the concepts described herein can be applied to other types of filter assemblies that filter other types of fluids, for example lubrication, hydraulic and other liquids, as well as air. 
         [0018]    The assembly  10  includes a filter housing  12  that is designed to receive a filter cartridge  14  therein for filtering the fluid. The filter housing  12  includes a housing body that has a side wall  16  and an end wall  18 . The side wall  16  and the end wall  18  define a filter cartridge space  20  that is large enough to receive the filter cartridge  14  therein, with the end wall  18  forming a closed end of the space  20 . The housing body has an open end generally opposite the end wall  18 , with the open end in use being closed by a lid  22  that closes off the space  20 . The housing body also includes an inlet opening  24  ( FIG. 2 ) through which fuel to be filtered enters the space  20 , and an outlet  26 , illustrated as extending from the end wall  18 , through which fuel exits on its way to the engine. It is to be realized that the filter housing  12  could have other configurations than that described herein. 
         [0019]    A fluid passageway member in the form of a standpipe  30  is secured to the end wall  18  and extends upwardly into the space  20  toward the open end and the cap  22 . In the illustrated embodiment, the standpipe  30  is generally hollow from its end  32  connected to the end wall  18  to a tip end thereof, thereby defining an internal flow passage  36 . The flow passage  36  is in communication with the outlet  26  so that fuel that enters the standpipe  30  can flow from the standpipe and into the outlet  26  to the engine. The standpipe  30  is disposed in the housing  12  which has a central axis A-A. In some embodiments, the axis A-A of the housing  12  can be off-center of the housing. 
         [0020]    The standpipe  30  can have a number of cross-sectional shapes, for example oval-shaped or circular. An example of an oval standpipe is disclosed in U.S. Pat. No. 6,884,349 and in U.S. patent application Ser. No. 11/780,176. 
         [0021]    A flow restriction valve  50  is disposed at the tip end of the standpipe  30  to control the flow of fuel into the standpipe. The valve  50  can prevent fuel flow into the standpipe when the filter cartridge  14  is not installed or when an incorrect filter cartridge is installed. When the filter cartridge  14  or other appropriately designed filter cartridge is installed, the filter cartridge is designed to interact with the valve in such a manner as to keep the valve from preventing fuel flow into the standpipe. An example of a valve operating in this manner is disclosed in U.S. Pat. No. 6,884,349 and in U.S. patent application Ser. No. 11/780,176. 
         [0022]    With reference to  FIGS. 1-3 , the filter cartridge  14  is illustrated as being of a filter-in-filter type with an inner filter  60  and an outer filter  62 . The inner filter  60  is designed to snap-fit connect with the outer filter  62  during assembly of the cartridge  14  to form an integral unit. 
         [0023]    The inner filter  60  includes a ring of filter media  64 , an upper end plate  66  secured to an upper end of the media  64 , and a lower end plate  68  secured to a bottom end of the media  64 . Likewise, the outer filter  62  includes a ring of filter media  70 , an upper end plate  72  secured to an upper end of the media  70 , and a lower end plate  74  secured to a bottom end of the media  70 . The end plates  66 ,  68 ,  72 ,  74  are formed of a suitable material, for example plastic. 
         [0024]    Fuel can include water therein in different forms, including free water, e.g. droplets, and emulsified water. Preferably, the filter media  70  is designed so that free water is initially stripped out when fuel enters the filter from the outside. The free water does not penetrate the media  70  and remains substantially outside the filter. The media  70  also coalesces the majority of the emulsified water and separates the now coalesced water from the fuel. The media  70  also retains soft and solid contaminants from the fuel. Water, being heavier than fuel, settles down to the bottom of the filter cartridge  14 , and drains through openings to a water collection area at the base of the housing  12 . By the time the fuel interfaces with the media  64 , most of the water has been separated, and the media  64  filters particles from the fuel before the fuel enters the center of the filter cartridge. The media  64  also strips remaining water from the fuel and prevents the water from entering the media  64 . The filtered fuel then enters the standpipe  30  and flows to the outlet  26 , leading to a downstream protected component, for example a fuel pump. 
         [0025]    The outside of the filter media  64  generally faces the interior of the filter media  70  of the filter  62 , with the inside of the ring of media  64  defining a clean or filtered fuel side of the filter cartridge  14  and the outside of the media  70  defining a dirty or unfiltered fuel side, whereby the filter cartridge is configured for outside-in flow. In appropriate circumstances, the concepts described herein can be applied to inside-out type flow filter cartridges. 
         [0026]    The upper end plate  72 , as illustrated in  FIGS. 3 and 4 , includes a first generally circular, horizontal plate  80 . A flange  82  extends downwardly from the plate  80 , and a generally horizontal ring  84  is connected to the flange  82  intermediate the ends of the flange and extends outwardly from the flange. The bottom surface of the ring  84  is suitably attached to the upper end of the filter media  70 , for example using an adhesive or using heat to fuse the ring  84  to the filter media. 
         [0027]    The plate  80  and the flange  82  define a hollowed-out area  86  that receives the end of the inner filter  60  as shown in  FIG. 3 . This permits use of a longer inner filter to increase the amount of filter media for filtering. Deformable ribs  88  are connected to the interior of the end plate  72  within the area  86 , extending between an interior surface of the plate  80  and an interior surface of the flange  82 . When the inner filter  60  is installed into the outer filter  62 , the upper end plate  66  engages the ribs  88 . Continued installation causes the ribs  88  to crush, ensuring a tight radial and axial connection between the upper end plate  66  and the upper end plate  72  to prevent relative axial and radial movement between the upper end of the filter  60  and the upper end plate  72  when the filters  60  and  62  are assembled. This prevents relative axial and radial motion between the inner and outer filters after the filters  60 ,  62  are assembled. Relative motion can cause a rattling noise which is sometimes perceived as a low quality filter. However, the inner filter  60  can rotate relative to the outer filter  62  as will be described below. 
         [0028]    With reference to  FIGS. 1 ,  4  and  8 , the edge of the plate  80  extends past the flange  82  to form a circumferential lip  90 . A mechanism is provided for connecting the lid  22  to the filter cartridge  14  via the end plate  72 . In particular, a plurality of resilient fingers  92  project downwardly from the lid  22 . Each finger  92  includes an enlarged end  94  by which the fingers  92  snap fit over the lip  90 . The end  94  includes an angled deflection surface  95  that engages the lip  90  when connecting the lid  22  to the cartridge  14  to cause the finger  92  to deflect radially to clear the lip  90 . The lid  22  also includes internal threads (not shown) which engage with external threads (not shown) formed at the upper end of the side wall  16  by which the lid  22  can be screwed onto the housing body. 
         [0029]    In use, the filter cartridge  14  can be connected to the lid  22  prior to inserting the cartridge into the housing, after which the lid  22  is threaded onto the side wall  16 . The fingers  92  can slide relative to the outer edge of the lip  90  to allow the lid  22  to rotate relative to the upper end plate  72 . Alternatively, the cartridge  14  can first be installed in the housing, and thereafter the lid  22  connected to the cartridge via the fingers  92  and the lid  22  threaded onto the wall  16 . Removal of the lid  22  occurs by unscrewing the lid and lifting the lid and cartridge  14  together from the housing. As the lid  22  is lifted upward, the ends  94  of the fingers  92  engage the lip  90 , causing the cartridge  14  to be lifted upwards as well. The cartridge  14  can then be removed from the lid  22  by manually deflecting the ends of the fingers  92  outward to disengage from the lip  90 . 
         [0030]    If desired, a handle can be attached to the upper surface of the plate  80  to facilitate handling of the cartridge  14 , for example lifting of the cartridge from the housing. However, the lip  90  also provides a means to allow a user to grab the cartridge  14  and lift it from the housing. Therefore, the handle is optional. 
         [0031]    Turning to  FIGS. 3 and 5 , the upper end plate  66  of the inner filter  60  includes a generally circular, horizontal plate  110 . The plate  110  includes a perimeter portion  112  that is suitably attached to the upper end of the filter media  64 , for example using an adhesive or using heat to fuse portion  112  to the filter media. A pin  114  projects downwardly from the center of the plate  110 . The pin  114  is designed to interact with the valve  50  in the manner described in U.S. Pat. No. 6,884,349 and in U.S. patent application Ser. No. 11/780,176. The pin  114  is connected to the plate  110  via four stiffening ribs  116  which provide stiffening to the pin  114 . 
         [0032]    Extending downward from the plate  110 , and surrounding the pin  114  and ribs  116 , is a protective skirt  118 . The skirt  118  is illustrated as being substantially solid from one end to the other, and the base  120  of the skirt  118  that is connected to the plate  110  and to the ends of the ribs  116 . If considered appropriate, holes or other flow enhancing means can be provided in the skirt  118  to facilitate the flow of fuel past the skirt and into the standpipe  30 . 
         [0033]    The lower end plate  68  of the inner filter  60  is illustrated in  FIGS. 3 ,  6 A and  6 B. The end plate  68  includes a generally ring shaped, horizontal plate  130  which is suitably attached to the bottom end of the filter media  64 , for example using an adhesive or using heat to fuse the plate  130  to the filter media. A standpipe hole  132  is formed at the center of the plate  130  which is configured to allow passage of the standpipe  30 . In the illustrated embodiment, the hole  132  is has a shape similar to the shape of the standpipe  30 , for example oval. However, if the standpipe has a different shape, for example circular, then the hole  132  can have a shape, for example circular, similar to the shape of the standpipe. 
         [0034]    A seal support  134 , for example a flange, extends downwardly from the plate  130  for supporting a seal  138  (visible in  FIG. 3 ) designed to seal with the outside surface of the standpipe  30  when the filter cartridge is installed. The support  134  can extend around the entire perimeter of the hole  132 , or only around portions thereof. In the illustrated embodiment, the seal support  134  comprises a plurality of spaced tabs  135  connected to the bottom surface of the plate  130 , and a ring-shaped ledge  136  at the base of the tabs  135  for supporting the bottom of the seal  138 . 
         [0035]    The seal  138  can have any shape suitable for sealing with the outside of the standpipe. For example, in the case of an oval shaped standpipe, the seal can be oval shaped; for a circular standpipe, the seal can be circular. In addition, the seal  138  can be secured to the support  134  in any suitable manner. For example, the seal  138  can be securing to the support  134  by interference fit, adhesives, etc. 
         [0036]    A plurality of flexible connection arms  142  are connected to the bottom of the plate  130  near the outer edge thereof, and extend downwardly from the plate  130  at an angle α, for example 20 degrees. The arms  142  can be, in the illustrated example, positioned at equally spaced intervals around the plate, although the spacing could be other than equal. In addition, in the illustrated embodiment there are four arms  142 , although a larger or smaller number of arms  142  could be used. The arms  142  each extend an angle so that ends  144  of the arms are positioned radially beyond the outer edge of the plate  130  a distance “d” ( FIG. 6B ). The arms  142  also help create a gap between the filter media  64 ,  70 . 
         [0037]    The arms  142  are used to help connect the lower end plate  68  of the inner filter  60  to the lower end plate  74  of the outer filter  62 . The end plate  74 , illustrated in  FIGS. 3 and 7 , includes a generally ring-shaped, horizontal plate  150  which is suitably attached to the bottom end of the filter media  70 , for example using an adhesive or using heat to fuse the plate  150  to the filter media. The plate  150  surrounds a hole  152  through which the inner filter  60  can be inserted into the outer filter  62 . The hole  152  is defined by a flange  154  that extends downwardly from the plate  150  around the entire perimeter of the hole  152  to help define the hole. 
         [0038]    An inwardly extending ledge  156  is formed at the base of the flange  154 . The ledge  156  forms a seat to receive the ends of the arms  142  of the lower end plate  68  of the inner filter  60  thereon as seen in  FIG. 3 . The outer diameter formed by the ends of the arms  142  is preferably greater than the inner diameter of the inner edge of the ledge  156  so that the arms  142  are compressed inward as the inner filter  60  is inserted into the outer filter  62 . Once the ends of the arms  142  clear the ledge  156 , the ends  144  spring outward to the position shown in  FIG. 3 . Thus, the design of the arms  142 , the flange  154  and the ledge  156  form a snap fit connection between the filters  60 ,  62 . The crush ribs  88  and the snap fit connection permits relative rotational movement between the outer filter  62  and the inner filter  60  about the central axis A-A to permit alignment of the opening  132  with the standpipe  30 . Although the snap fit connection has been described as being between the end plates  68 ,  74 , the snap fit connection could be between the end plates  66 ,  72 , or between other parts of the filters  60 ,  62 . 
         [0039]    Returning to  FIG. 7 , a cut-out  158  is formed around the outer perimeter of the flange  154  of the lower end plate  74 . The cut-out  158  receives a seal  160  therein ( FIG. 3 ) that is designed to seal with an interior surface of the side wall  16  of the housing as shown in  FIG. 1 . 
         [0040]    The filter cartridge  14  interacts with and actuates the valve  50  in the manner described in U.S. Pat. No. 6,884,349 and U.S. patent application Ser. No. 11/780,176. However, the concepts described herein can be used in other manners and in technologies other than fuel filtration. 
         [0041]    The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.