Abstract:
A “no filter, no run” filtration system that is designed to verify that an appropriate filter cartridge is installed. A flow control sleeve is provided on a standpipe to control the flow of fluid, for example fuel, into the standpipe. The sleeve can be axially moveable between closed and open positions, with one or more members on an installed filter cartridge designed to release the sleeve to permit the movement from the closed position to the open position to allow fluid flow. A spring acts on the sleeve to bias the sleeve back to the closed position upon removal of the filter cartridge. The sleeve can also be designed without axial movement, but nonetheless is configured to be opened and closed to control fluid flow into the standpipe.

Description:
FIELD 
       [0001]    This disclosure generally pertains to the field of filtration, and more particularly to fuel filtration systems designed to safe-guard against damage to fuel injectors, associated fuel components, and engine malfunctions resulting from a missing or incorrect fuel filter. 
       BACKGROUND 
       [0002]    Fuel filtration systems are known that are designed to prevent flow of fuel to an engine if no filter cartridge is installed or in the incorrect filter cartridge is installed. In these “no filter, no run” systems, not only must a filter cartridge be present, but the correct filter cartridge must be used, in order to allow fuel to flow to the engine. 
         [0003]    In some fuel filtration systems that use a filter cartridge, whether in a “no filter, no run” system or not, removal and servicing of the filter cartridge can be difficult. Therefore, a fuel filtration system that enhances filter cartridge removal and servicing would be beneficial. 
       SUMMARY 
       [0004]    A “no filter, no run” filtration system that is designed to verify that a filter cartridge is present to safe-guard against damage to fuel injectors, associated fuel components, etc. and engine malfunctions. Fuel flow to the engine is substantially prevented if a filter cartridge is not installed, and an appropriately designed filter cartridge is required to be used in order to permit sufficient fuel flow. 
         [0005]    A flow control sleeve is provided on a standpipe to control the flow of fuel into the standpipe. The sleeve can be axially moveable between closed and open positions, with one or more members on an installed filter cartridge designed to release the sleeve to permit the movement from the closed position to the open position to allow fuel flow. A spring acts on the sleeve to bias the sleeve back to the closed position upon removal of the filter cartridge. The bias of the spring also creates a positive force that acts on the filter cartridge in the removal direction through the sleeve thus facilitating a more effortless cartridge removal. The sleeve can also be designed without axial movement, but nonetheless is configured to be opened and closed to control fuel flow into the standpipe. 
         [0006]    In one embodiment, a filter housing includes a standpipe and a flow control sleeve surrounds at least a portion of the standpipe. The sleeve includes at least one opening through the sleeve, and the sleeve is slideably disposed on the standpipe for movement between a first position where the sleeve covers the standpipe opening and a second position where the sleeve opening is at least partially aligned with the standpipe opening. When the standpipe opening is covered, fuel is substantially prevented from flowing into and through the standpipe, thereby preventing engine operation. When the sleeve opening and the standpipe opening align, fuel can flow into and through the standpipe and ultimately to the engine. To actuate the sleeve to the second position, an appropriately designed filter cartridge must be installed in the filter housing. 
         [0007]    In another embodiment, a filter housing includes a standpipe with a standpipe opening and a sleeve surrounds at least a portion of the standpipe including the standpipe opening. The sleeve includes a plurality of resilient fingers that are deflectable from a first position to a second position. The standpipe opening is covered when the fingers are in the first position to prevent flow through the standpipe and the standpipe opening is not covered when the fingers are at the second position to permit flow through the standpipe. 
         [0008]    The fingers can close and open the standpipe opening without axial movement of the sleeve, in which case deflection of the fingers to the second position uncovers the standpipe opening sufficiently to allow fuel to flow through gaps created between the fingers and into the standpipe opening. Alternatively, the sleeve can be designed to move axially to control flow through the standpipe opening, with the deflection of the fingers controlling axial movement of the sleeve. 
         [0009]    The fingers are deflected by one or more protrusions on a filter cartridge that is installed. In one embodiment, the protrusions can remain engaged with the fingers at the second position and retain the fingers under load at the second position when the standpipe opening is not covered. In another embodiment, a tapered recess, slot or groove can be incorporated on the standpipe to unload the fingers until the cartridge is removed and the bias spring resets the sleeve. 
         [0010]    When the sleeve is designed to move axially, a spring can be provided that biases the sleeve to a closed position. Since the sleeve is engaged with the filter cartridge, the spring also facilitates removal of the filter cartridge by applying a bias to the filter cartridge to lift the cartridge upward in a cartridge removal direction. This facilitates removal of the cartridge from the filter housing. 
         [0011]    In certain designs, the flow control sleeve can be designed to permit a certain amount of fuel flow past the sleeve and into the standpipe. The amount of fuel flow permitted when the sleeve is closed should be insufficient to operate the engine. In some designs, the sleeve can be manufactured to less exacting tolerances since it need not completely shut off fuel flow, thereby reducing the cost of manufacture of the sleeve. In other designs, the sleeve and/or standpipe can be manufactured with features to permit flow. Nonetheless, the amount of fuel flow permitted when the sleeve is closed is low enough that engine operation is prevented. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a side sectional view of a filter assembly that includes a filter cartridge and a filter housing. 
           [0013]      FIG. 2  is a perspective view of the flow control sleeve on the standpipe. 
           [0014]      FIG. 3  shows the flow control sleeve in  FIG. 1  actuated to an open position. 
           [0015]      FIGS. 4 and 5  are exploded views of the flow control sleeve and the end of the standpipe of  FIGS. 1-3 . 
           [0016]      FIGS. 6-8  illustrate an alternative embodiment of a flow control sleeve, with  FIG. 6  being a side view and  FIGS. 7-8  being cross-sectional views. 
           [0017]      FIGS. 9 and 10  illustrate yet another alternative embodiment of a flow control sleeve. 
           [0018]      FIG. 11  illustrates yet another embodiment of a flow control sleeve. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIG. 1  illustrates a filter assembly  10 , for example a fuel filter assembly, which is intended to filter a fluid, for example fuel, prior to the fluid reaching an engine. The assembly  10  includes a filter housing  12  that is designed to receive a filter cartridge  14  therein for filtering the fluid. The description will hereinafter refer to the filter assembly  10  as being a fuel filter assembly, and that the fluid being filtered is fuel. However, in appropriate circumstances, the concepts described herein can be applied to other types of filter assemblies that filter other types of fluids. 
         [0020]    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  22  generally opposite the end wall  18 , with the open end  22  in use being closed by a cap (not shown) that closes off the space  20 . The housing body also includes an inlet opening  24 , illustrated in  FIG. 1  as extending through the side wall  16 , 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. 
         [0021]    A standpipe  30  is secured to the end wall  18  and extends upwardly into the space  20  toward the open end  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  34  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 generally centrally in the housing  12 , with a central axis A-A of the standpipe  30  generally coaxial with a central axis of the space  20 . 
         [0022]    In the embodiment illustrated in  FIG. 1 , the standpipe  30  is generally cylindrical and the passage  36  is generally circular along its length when the standpipe  30  is viewed in a cross-section taken perpendicular to the axis A-A. However, the standpipe  30  and the passage  36  could have other configurations, such as non-cylindrical and non-circular. For example, the passage  36  could be oval in cross-section. 
         [0023]    The standpipe  30  is stepped in diameter to define different diameter sections  40   a ,  40   b ,  40   c . The section  40   a  extends from the end wall  18  for the majority of the length of the standpipe  30 . The section  40   b , which has a smaller diameter than the section  40   a , extends upwardly from the section  40   a . A shoulder  42  is defined at the juncture of the sections  40   a ,  40   b . The section  40   c , which has a smaller diameter than the section  40   b , extends upwardly from the section  40   b  and includes the tip end  34 . A shoulder  44  is defined at the juncture of the sections  40   b ,  40   c.    
         [0024]    A flow control sleeve  50  is slideably disposed on the standpipe  30  adjacent the tip end  34 . With reference to  FIGS. 2-5 , the sleeve  50  comprises a generally circular body  52  having a first section  54  with one or more slots  56  extending through the body  52  and a second section  55  with one or more flow openings  57 . As shown in  FIG. 2 , the openings  57  are positioned at circumferential locations on the sleeve  50  between the slots  56 . The sleeve  50  is made of a material suitable for exposure to fuel or other type of fluid flowing through the assembly  10 . For example, the sleeve  50  can be made of plastic or metal. 
         [0025]    A plurality of resilient fingers  58  are secured to the upper section  54  and extend into the body  52 . The fingers  58  are integrally formed with the body  52 , and are thus made of the same material as the body  52 . The fingers  58  extend from their point of attachment to the body  52  downward into the interior of the body spaced from the interior surface of the body  52 . As shown in  FIG. 3 , the fingers  58  decrease in width (i.e. taper) as they extend from their attachment point to the body to unattached, distal ends  60  which are spaced from the distal ends of adjacent fingers  58 . As shown in  FIG. 1 , the fingers  58  also normally angle toward each other and the central axis A-A, with the distal ends  60  defining an opening. 
         [0026]    Due to their construction, the ends  60  of the fingers  58  are resilient and can be deflected generally radially outward to the position shown in  FIG. 3  upon application of a suitable force to actuation surfaces thereof that face generally inwardly toward the central axis A-A. Upon removal of that force, the fingers  58  automatically return to their position shown in  FIG. 1 . 
         [0027]    With reference to  FIGS. 1 and 3 , the section  40   c  of the standpipe  30  includes a circular support shoulder  62  at the tip end  34  on which the distal ends  60  are received at the closed position of the sleeve  50 . A coil spring  64  extends between the shoulder  44  and the interior of the sleeve  50  where the fingers  58  connect to the body  52 . The spring  64  biases the sleeve  50  in a direction away from the end wall  18 , i.e. in a direction opposite an insertion direction of the filter cartridge into the housing. Small protrusions  66  on the outside of the standpipe  30  engage within the slots  56  in the sleeve  50  to limit axial movement of the sleeve toward and away from the end wall  18  as well as limiting rotational movement of the sleeve  50 . 
         [0028]    One or more openings  70  are formed in the section  40   b  of the standpipe  30  to place the exterior of the standpipe in communication with the passage  36 . In the illustrated embodiment, the number of openings  70  corresponds to the number of openings  57  formed in the sleeve  50 . However, a larger or smaller number of openings  70  can be provided. The openings  70  are positioned at circumferential positions that correspond to the openings  57 , without overlapping the slots  56 . Therefore, fluid is prevented from flowing through the slots  56  and into the openings  70 . 
         [0029]    The sleeve  50  is configured such that at the closed position shown in  FIG. 1 , the first section  54  of the sleeve covers the openings  70 , to thereby prevent fuel from entering into the standpipe  30 . Upon movement of the sleeve to the open position shown in  FIG. 3 , the openings  57  in the sleeve align with the openings  70  to permit fuel to flow into the standpipe. 
         [0030]    Movement of the sleeve  50  to the open position occurs as a result of installing the correct filter cartridge  14 . Returning to  FIG. 1 , the cartridge  14  includes a ring of filter media  80  suitable for filtering fuel. The outside of the filter media  80  defines a dirty or unfiltered fuel side while inside the ring of media  80  is a clean or filtered fuel side. Thus, the filter cartridge is configured for outside-in flow. 
         [0031]    A first end cap or plate  82  is secured to the bottom end of the media  80  for generally closing the bottom end of the media. The plate  82  includes an opening  84  therethrough through which the standpipe is inserted upon installation of the filter cartridge. A seal (not shown) will typically be provided on the plate  82  to seal with the standpipe  30  to prevent leakage of clean fuel past the plate  82 . A second end cap or plate  86  is secured to the opposite end of the media  80  for closing off the opposite end of the media. 
         [0032]    In the illustrated embodiment, the plate  86  is generally flat and planar. Except that the plate  86  includes a projection  90  that projects along the axis A-A downwardly into the interior space of the media  80 . The projection  90  is designed to actuate the fingers  58  and deflect them radially to release the fingers from the shoulder  62  and permit axial movement of the sleeve. The projection  90  is wider than the section  40   c  of the standpipe so that the fingers  58  are deflected outward a sufficient distance to clear the shoulder  62 . 
         [0033]    As illustrated in  FIGS. 1 and 3 , the projection  90  is designed to extend into the end of the sleeve  50  and engage the fingers  58  when the filter cartridge  14  is installed. As the projection  90  travels downward, the projection deflects the fingers  58  radially outward, which disengages the ends  60  of the fingers from the shoulder  62 . This permits the weight of the filter cartridge  14  acting on the top end of the sleeve  50  and the force from the person installing the filter cartridge  14  to force the sleeve  50  downward until the ends  60  of the fingers engage the shoulder  44 . At this position, the openings  57  will be aligned with the openings  70  to permit fuel to enter into the standpipe. 
         [0034]    In the illustrated embodiment, when the sleeve  50  is open, the projection  90  remains in contact with the fingers  58  and keeps the fingers  58  under load. In an alternative embodiment, a tapered recess, slot or groove can be provided on the standpipe  30  to unload the fingers  58  when the sleeve  50  is open. The recess, slot or groove would allow release of the fingers therefrom when the cartridge is removed and the bias spring  64  resets the sleeve  50 . 
         [0035]    Upon removal of the filter cartridge  14 , the spring  64  will bias the sleeve  50  upward to the position shown in  FIG. 1 , thereby preventing fuel flow into the standpipe until the correct filter cartridge with a protrusion that can release the fingers is installed. If a standard filter cartridge without a suitable protrusion is installed, the sleeve will not slide down the standpipe, and the filter cartridge will project upward from the housing  12  and prevent installation of the housing cover. This will act as a sign that the incorrect filter cartridge has been installed. 
         [0036]    With reference to  FIGS. 6-8 , an alternative embodiment of a flow control sleeve  100  is illustrated. The sleeve  100  is slideably disposed on a standpipe  102  that includes an opening  104  into the interior of the standpipe. 
         [0037]    The sleeve  100  includes a generally circular body with a solid section  108  and an upper section with one or more openings  110  extending through the body  106 . A plurality of resilient fingers  112  extend upwardly from an upper end  114  of the body  106 , with a shoulder  116  defined between the fingers  112  and the end  114 . A coil spring  118  is disposed within the sleeve  100 , engaged between the shoulder  116  and a shoulder  120  on the standpipe  102 . The spring  118  biases the sleeve  100  upwardly away from an end wall of the housing containing the standpipe to a closed position shown in  FIGS. 6 and 7 . 
         [0038]    The fingers  112  comprise a plurality of fingers disposed at spaced locations around the sleeve  100 . Upper ends  122  of the fingers flare outwardly, and each finger  112  includes a protrusion  124  projecting inwardly at the base of the flared end  122 . The protrusions  124  engage with a shoulder  126  defined on the standpipe  102  to prevent downward axial sliding movement of the sleeve  100  and retain the sleeve at a closed position. At the closed position, the solid section  108  covers the standpipe opening  104  to prevent fuel flow into the standpipe. 
         [0039]    However, the fingers  112  are deflectable generally outward in a radial direction as a result of a force being applied to the flared ends  122 . When deflected outward, the engagement between the protrusions  124  and the shoulder  126  is released, allowing the sleeve to slide axially downward to an open position as shown in  FIG. 8 . In the open position, the opening  110  in the sleeve aligns with the standpipe opening  104  to permit fuel flow into the standpipe. 
         [0040]    Deflection of the fingers  112  is caused by suitable structure on an upper end plate  130  of a filter cartridge when the filter cartridge is installed. Only the end plate  130  of the filter cartridge is illustrated in  FIGS. 7 and 8 , the remainder of the filter cartridge not being important to describing the operation of the sleeve  100 . The end plate  130  includes a circular protrusion  132  that projects downwardly therefrom. The protrusion  132  includes a central recess  134  that receives the end of the standpipe when the cartridge is installed, a projecting rim  136  surrounding the recess  134 , a radial surface  138 , and an axial surface  140 . The rim  136  includes an angled surface  142  that extends from the radial surface  138 . 
         [0041]    With reference to  FIG. 7 , when the filter cartridge is installed, the angled surface  142  of the protrusion  132  engages the flared ends  122  of the fingers  112 , which causes the ends of the fingers  112  to deflect outwardly. This deflection releases the protrusions  124  and the shoulder  126 , thereby permitting the sleeve  100  to slide downward. As shown in  FIG. 8 , the sleeve  100  is pushed downward against the bias of the spring  118 , eventually reaching the point where the openings  104 ,  110  are aligned. 
         [0042]    When the sleeve  100  is open, the protrusion  132  remains in contact with the fingers  112  and keeps the fingers  112  under load. However, a tapered recess, slot or groove can be provided on the standpipe that receives the protrusions  124  to unload the fingers  112  when the sleeve  100  is open. 
         [0043]    Upon removal of the filter cartridge, the spring  118  will bias the sleeve  100  upward to the position shown in  FIG. 7 , thereby preventing fuel flow into the standpipe until the correct filter cartridge with a protrusion that can release the fingers is installed. If a standard filter cartridge without a suitable protrusion is installed, the sleeve will not slide down the standpipe, and the filter cartridge will project upward from the filter housing and prevent installation of the housing cover. This will act as a sign that the incorrect filter cartridge has been installed. 
         [0044]    Another alternative embodiment of a flow control sleeve  200  is illustrated in  FIGS. 9 and 10 . The sleeve  200  is slideably disposed on a standpipe  202  that includes an opening  204  into the interior of the standpipe. In this embodiment, the sleeve  200  includes resilient, deflectable fingers  206  extending upwardly from the end of the sleeve  200 . The fingers  206  include protrusions  208  that engage within a recess or recesses  210  in the outside surface of the standpipe to retain the sleeve  200  at a closed position where the sleeve  200  prevents fuel flow into the standpipe opening  204 . The fingers  206  must be deflected outwardly to release the engagement between the protrusions  208  and the recess  210  to allow the sleeve  200  to slide downward in an axial direction. 
         [0045]    Deflection of the fingers  206  is caused by a protrusion  220  formed on an upper end plate  222  of a filter cartridge. The protrusion  220  includes a central recess  224  that receives the end of the standpipe and a similar rim structure  226  as the rim described in  FIGS. 6-8 . With reference to  FIGS. 9 and 10 , when the filter cartridge is installed, the rim structure  226  of the protrusion  220  engages the ends of the fingers  206 , deflecting the fingers outwardly to release the protrusions  208  from the recess  210 . The sleeve  200  can then slide down to align an opening in the sleeve with the standpipe opening  204 . 
         [0046]    Upon removal of the filter cartridge, a coil spring  230  biases the sleeve  200  upwardly until the protrusions  208  engage within the recess  210 , thereby locking the sleeve at the closed position. 
         [0047]      FIG. 11  illustrates an embodiment of a sleeve  300  that slides axially and which is similar to the sleeve  200  in  FIGS. 9 and 10 , but the sleeve does not include an opening that aligns with a standpipe opening  302 . Instead, deflection of fingers  304  allows the sleeve to slide downward. Gaps  306  between the fingers  304  permits fuel to flow into the standpipe opening  302  through the gaps  306  between the fingers  304 . A coil spring  308  biases the sleeve  300  back to the closed position upon removal of the filter cartridge. 
         [0048]    In an embodiment somewhat similar to  FIG. 11 , a sleeve can be designed without axial movement, but where fingers deflect outwardly to uncover a standpipe opening that is covered by the fingers which are relatively closely spaced together. When the fingers deflect outwardly, gaps created between the fingers allow fuel to flow into the standpipe opening. When the filter cartridge is removed, the fingers deflect back to their closed position covering the standpipe opening to prevent fuel flow into the standpipe. Since the sleeve does not move axially, a biasing spring is not required in this embodiment. 
         [0049]    In all of the embodiments described herein, the sleeves have been described as preventing fuel flow into the standpipe when the sleeve is at a closed position. However, it is contemplated that the embodiments described herein could be designed to permit a certain amount of fuel to flow into the standpipe when the sleeve is at the closed position. The amount of fuel permitted to flow when the sleeve is closed should be insufficient to permit engine operation. This permits the sleeves described herein to be manufactured to less exacting tolerances since they would not need to completely shut off fuel flow. This would permit reduction in the cost of manufacture of the sleeve, since it need not fit closely onto the standpipe. Alternatively, the sleeve and/or standpipe can be manufactured with features to permit fuel to flow into the standpipe when the sleeve is closed. For example, grooves or channels could be provided on the sleeve and/or standpipe to permit limited fuel flow when the sleeve is at the closed position. Therefore, the word prevention of fuel flow (or similar) as used herein, unless indicated otherwise, is meant to include complete shut off of fuel, as well as allowing limited flow of fuel as long as the amount of fuel is insufficient to permit engine operation. 
         [0050]    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.