Abstract:
A valve assembly that is useable with a fuel filter housing to control the flow of fuel through the fuel filter housing. The valve assembly comprises two primary parts that are connected together via a snap connection, and when the valve assembly is installed on the fuel filter housing, means on the fuel filter housing prevent disconnection of the snap connection. One or both of the primary parts of the valve assembly can be provided with a tamper evident feature that will indicate whether someone has tried to remove or disassemble the valve assembly.

Description:
FIELD 
       [0001]    This disclosure generally pertains to the field of filtration, and more particularly to a fuel filter housing with a valve that controls fuel flow through the fuel filter housing. 
       BACKGROUND 
       [0002]    It is known to use a valve in a fuel filter housing to control fuel flow through the housing. One example of such a valve in a fuel filter housing is sometimes referred to as a “no filter, no run” valve, where the valve prevents flow of fuel to the engine if no fuel filter is installed or if the incorrect fuel filter is installed. In this type of system, not only must a fuel filter be present, but the correct fuel filter must be used, in order to allow fuel to flow past the valve to the engine in sufficient quantities to allow the engine to function properly. However, if the valve is removed, fuel can flow to the engine if no filter is installed or if an incorrect filter is installed. 
       SUMMARY 
       [0003]    A valve assembly that is useable with a fuel filter housing to control the flow of fuel through the fuel filter housing. The valve assembly comprises two primary parts that are connected together via a snap connection, and when the valve assembly is installed on the fuel filter housing, means on the fuel filter housing prevent disconnection of the snap connection. One or both of the primary parts of the valve assembly can be provided with a tamper evident feature that will indicate whether someone has tried to remove or disassemble the valve assembly. 
         [0004]    The valve assembly can be used at any location in or on the fuel filter housing for controlling fuel flow through, including into, the fuel filter housing. One exemplary use of the valve assembly is on a post in the fuel filter housing as part of a “no filter, no run” system. In a “no filter, no run” system, fuel flow to the engine is prevented altogether or permitted in an amount insufficient to allow engine operation if a filter is not installed or if an incorrect filter is installed, and an appropriately designed filter is required to be used in order to permit sufficient fuel flow for engine operation. 
         [0005]    The valve assembly is designed to lock to the filter housing, thereby preventing someone from removing or tampering with the valve assembly. In addition, the valve assembly is designed to give visual evidence if someone tries to tamper with the valve assembly or remove the valve assembly from the filter housing. 
         [0006]    In one embodiment, a valve assembly for attachment to a fuel filter housing for controlling fuel flow through the fuel filter housing includes a first valve assembly piece configured for attachment to the fuel filter housing, and a second valve assembly piece connected to the first valve assembly piece. A snap connection between the first piece and the second piece is provided by which the first piece and the second piece snap fit connect to each other. The snap connection is configured and positioned such that when the valve assembly is attached to the fuel filter housing, disconnection of the snap connection is prevented by a suitable means on the fuel filter housing. 
         [0007]    When the valve assembly is used on a post of the filter housing, the means to prevent disconnection of the snap connection can be, for example, a raised lip on the post that interfaces with the back side of the snap connection to prevent disconnection, or a groove formed in the end of the post that receives a portion of the snap connection. 
         [0008]    In addition, a tamper evident feature can be provided on one or both of the valve assembly pieces. The tamper evident feature can be, for example, an engineered weak point formed on the first valve assembly piece and/or the second valve assembly piece. The engineered weak point creates a weak point in the part so that if someone tries to tamper with or remove one or both of the valve assembly pieces, the part can break at the weak point and cannot be reattached. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a cross-sectional view of a fuel filter housing that incorporates the snap lock valve assembly, with the snap lock valve assembly attached to the housing. 
           [0010]      FIG. 2  is a side view of a valve body of the valve assembly. 
           [0011]      FIG. 3  is a cross-sectional view of the valve body of  FIG. 2  taken along line  3 - 3 . 
           [0012]      FIG. 4  is a side view of the valve cover of the valve assembly. 
           [0013]      FIG. 5  is a cross-sectional view of the valve cover of  FIG. 4  taken along line  5 - 5 . 
           [0014]      FIG. 6  is a cross-sectional view of the valve assembly with the valve cover partially connected to the valve body. 
           [0015]      FIG. 7  is a cross-sectional view of the valve assembly with the valve cover and the valve body fully connected. 
           [0016]      FIG. 8  is a detailed cross-sectional view of the area contained within circle  8  of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  illustrates a filter housing  10 , for example a fuel filter housing, that is designed to receive a filter (not shown) therein that is intended to filter a fluid, for example diesel fuel, before the fluid reaches a protected system, for example a fuel injection pump and fuel injectors. In appropriate circumstances, one or more of the concepts described herein can be applied to other types of filters that filter other types of fluids, for example lubrication, hydraulic and other liquids, as well as air. 
         [0018]    As discussed further below, a valve assembly is described that attaches to the filter housing  10  for controlling fuel flow through the housing. The concepts of the valve assembly described herein can be applied to any valve assembly used to control fuel flow through, including into, the filter housing  10 . For sake of convenience in explaining the inventive concepts, the valve assembly will be described as being attached to a post in the filter housing. However, the inventive concepts can be applied to a valve assembly attached anywhere in or on the filter housing. 
         [0019]    The filter housing  10  is of generally conventional construction and includes a housing body that has a side wall  12  and an end wall  14 . The side wall  12  and the end wall  14  define a filter space  16  that is large enough to receive the filter therein, with the end wall  14  forming a closed end of the space  16 . The housing body has an open end generally opposite the end wall  14 , with the open end in use being closed by a lid that closes off the space  16 . The housing body also includes an inlet opening through which fuel to be filtered enters the space  16 , and an outlet  18 , illustrated as extending from the end wall  14 , through which fuel exits on its way to the engine. It is to be realized that the filter housing  10  could have other configurations than that described herein. 
         [0020]    A fluid passageway member in the form of a post  20  is secured to the end wall  14  and extends upwardly into the space  16 . In the illustrated embodiment, the post  20  is generally hollow from its end  22  connected to the end wall  14  to a tip end  24  thereof, thereby defining an internal fluid passageway  26 . The fluid passageway  26  is in communication with the outlet  18  so that fuel that enters the post  20  can flow from the post and into the outlet  18  to the engine. The post  20  is illustrated as being centrally disposed in the housing  10  coaxial with a central axis of the housing. In other embodiments, the post  20  can be disposed offcenter from the central axis of the housing  10 . 
         [0021]    In one embodiment, the post  20  is generally oval-shaped from the end  22  to the tip end  24 , similar to the posts disclosed in U.S. Pat. No. 6,884,349 and in U.S. patent application Ser. No. 11/937,700, which are herein incorporated by reference in their entirety. While this disclosure describes the post as being oval-shaped, it is to be realized that the concepts described herein could be used with a circular-shaped post and with posts having other shapes. 
         [0022]    A flow restriction valve assembly  30  is attached to the tip end  24  of the post  20  to control the flow of fuel into the post  20  and thus to the outlet  18 . In one embodiment, when the valve of the valve assembly  30  is closed, all flow of fuel into the standpipe  20  is substantially prevented when no filter is installed or when an improper filter is installed. In an alternative embodiment, when the valve of the valve assembly is closed, the valve assembly is designed to allow limited flow of fuel into the post  20  when no filter is installed or when an improper filter is installed. This limited flow allows lubrication of downstream components, such as a fuel pump, but is insufficient to allow the engine to operate. When an appropriately designed filter is installed, the filter is designed to keep the valve of the valve assembly at an open position to permit maximum fuel flow into the post. 
         [0023]    In the illustrated embodiment, the valve assembly  30  includes a first valve assembly piece in the form of a valve body  32  that is configured for attachment to the post  20 , and a second valve assembly piece in the form of a valve cover  34  configured for attachment to the valve body  32 . The valve body  32  and the valve cover  34  are designed to capture a valve ball (not shown) therein. The valve ball controls fluid flow through the valve assembly and into the post  20 . The valve body  32  and the valve cover  34  are made of material compatible with the fluid with which it interacts. In the case of fuel, the valve body and valve cover are made of a fuel resistant plastic. An example of a valve body, a valve cover and a valve ball is disclosed in U.S. patent application Ser. No. 11/937,700. 
         [0024]    With reference to  FIGS. 2 and 3 , the valve body  32  includes a first, lower portion  40  that is generally straight and elongated and configured to fit inside the fluid passageway  26  of the post  20  via a relatively tight interference fit between the outside surface of the first, lower portion  40  and the inside surface of the post  20 . In the case of the oval-shaped post  20 , the outside surface of the portion  40  of the valve body  32  that fits within the post will be generally oval-shaped. The lower portion  40  defines a fluid flow passage  42  that is in communication with the fluid passageway  26  when the valve assembly  30  is installed on the post. 
         [0025]    The valve body  32  also includes a second, upper portion  44 . The upper portion  44  defines a valve ball track  46  having a first end and a second end at an outer edge of the upper portion. A wall  48  of the upper portion  44  defines a fluid opening  50  at the first end of the ball track  46  that is at least partially closeable by a valve ball that in use rides on the valve ball track. The fluid opening  50  places the exterior of the valve body  32  in fluid communication with the fluid flow passage  42 . Further information on the construction of the upper portion of the valve body  32 , including the ball track, valve ball, and the fluid opening, can be found in U.S. patent application Ser. No. 11/937,700. 
         [0026]    As also shown in  FIG. 2 , a plurality of snap tabs  52   a ,  52   b  are connected to the first portion  40  of the valve body  32 . The snap tabs  52   a ,  52   b  are generally identical in construction so only the snap tab  52   a  will be described in detail. Although only two snap tabs are illustrated, it is to be understood that more than two snap tabs can be provided. 
         [0027]    The snap tab  52   a  comprises an elongated, relatively thin piece of plastic material which in the illustrated example is integrally formed with the remainder of the valve body  32 . The snap tab  52   a  includes an angled end  54  that integrally connects the snap tab to the first portion  40  and that spaces the snap tab  52   a  from the outer surface of the first portion  40  to provide a gap  56  therebetween. The opposite end  58  of the snap tab  52   a  is free, i.e. not directly connected to the first portion  40 , to allow the end  58  to flex. The end  58  is provided with an angled surface  60  the purpose of which will be described below. In addition, the snap tab  52   a  is provided with a lip  62  on the outer surface thereof designed to engage with the valve cover in a manner described below. 
         [0028]    The valve body  32  is also provided with a tamper evident feature  64 . In the illustrated embodiment, the feature  64  is an engineered weak point in the form of a circumferential notch that is formed in the first portion  40  generally adjacent the ends  58  of the snap tabs  52   a ,  52   b . The engineered weak point creates a weak point in the valve body  32  at which the valve body  32  can more readily break if someone tries to remove the valve body or otherwise tamper with the valve body  32 . Once broken, the valve body  32  cannot be reattached to the post  20 . Although a circumferential notch is illustrated, any other form of engineered weak point or any feature than can suitably indicate attempted tampering, can be used. 
         [0029]    With reference to  FIGS. 4 and 5 , the valve cover  34  comprises a generally hollow structure with a lower skirt portion  70  and a conical top portion  72 . The valve cover  34  is designed to fit over the valve body  32  and to capture the valve ball on the track  46 . The interior of the skirt portion  70  fits relatively closely with the exterior of the valve body  32 . The interior of the skirt portion includes shoulders  74  that engage with shoulders  76  on the valve body  32  when the valve cover  34  is fully inserted onto the valve body  32  as shown in  FIG. 7 . 
         [0030]    The skirt portion  70  also includes a plurality of windows  78   a ,  78   b  that engage with the snap tabs  52   a ,  52   b . The number of windows  78   a ,  78   b  preferably corresponds to the number of snap tabs  52   a ,  52 , although the number of windows could outnumber the number of snap tabs. The skirt portion  70  also includes a fluid inlet  80  that allows fluid to enter the valve cover  34  and ultimately flow to the fluid opening  50  and into the post  20 . When the valve cover  34  is installed, the fluid inlet  80  is disposed adjacent the second end of the ball track  46 . The fluid inlet  80  is configured such that the ball cannot escape out the inlet  80 . 
         [0031]    The conical top portion  72  includes a shoulder  82  on the inside surface thereof adjacent the top that engages with the top of the valve body  32  to also help define the fully inserted position of the valve cover on the valve body. A wall  84  is disposed at the top of the conical portion  72  that generally closes the top end of the valve cover. However, a pin opening  86  is formed in the wall  84  through which a blocking pin can extend down towards the ball track  46  to block the ball and prevent the ball from blocking the fluid opening  50 . Further information on blocking pins is disclosed in U.S. Pat. No. 6,884,349 and in U.S. patent application Ser. No. 11/937,700. 
         [0032]    As shown in  FIGS. 4 and 5  as an alternative to, or in addition to, the tamper evident feature  64  on the valve body  32 , the valve cover  34  can include a tamper evident feature  88 . The feature  88  can be an engineered weak point in the form of a circumferential notch that is formed in the skirt portion  70  above the windows  78   a ,  78   b . The notch creates a weaker point in the valve cover  34  at which the valve cover  34  can more readily break if someone tries to remove the valve cover or otherwise tamper with the valve cover  34 . 
         [0033]      FIG. 6  shows the valve cover  34  partially installed on the valve body  32 , while  FIG. 7  shows the valve cover  34  fully installed on the valve body  32  to form the valve assembly  30 . As the valve cover is being installed onto the valve body, the interior surface of the skirt portion  70  slides along the outer surface of the snap tabs  52   a ,  52   b . When the bottom edge  90  reaches the lips  62 , the edge  90  engages the sloped surfaces  92  ( FIG. 2 ) of the lips, thereby causing the snap tabs  52   a ,  52   b  to deflect inward. As soon as the bottoms of the windows  78   a ,  78   b  clear the lips  62 , the snap tabs  52   a ,  52   b  snap or deflect outward so that the bottom edges  94  ( FIG. 2 ) of the lips  62  are positioned above the bottom edges of the windows in blocking position to prevent removal of the valve cover. 
         [0034]    The valve assembly  30  is then installed onto the post  20 . The lower portion  40  of the valve body  32  is inserted into the fluid passageway  26  of the post  20  through the open tip end  24 . The interference fit between the lower portion  40  and the interior of the post  20  prevents fluid leakage and ensures tight connection between the valve assembly and the post. 
         [0035]      FIG. 1  shows the fully installed position of the valve assembly  30  on the post  20 . When the valve assembly  30  is fully installed, the bottom edge  90  of the valve cover  34  engages the top surface of the post  20  to limit the insertion, as best seen in  FIG. 8 . To deter removal of the valve assembly, the post  20  is provided with means to prevent removal of the valve cover  34  from the valve body  32 . 
         [0036]    As shown in  FIG. 8 , the means to prevent removal comprises a lip  100  formed on the top surface of the post  20 . The lip  100  includes an angled blocking surface  102 . When the valve assembly  30  is installed, the lip  100  is disposed behind the ends  58  of the snap tabs  52   a ,  52   b  to prevent inward deflection of the snap tabs. This prevents removal of the valve cover  34  because the snap tabs cannot be deflected inwardly sufficiently to deflect the lips out of the windows. At the same time, the angled surfaces  60  at the ends  58  of the snap tabs  52   a ,  52   b  engage the angled blocking surface  102 . This engagement forces the ends  58  of the snap tabs  52   a ,  52   b  outward which helps ensure that the lips  62  remain in the windows  78   a ,  78   b  to prevent removal of the valve cover  34 . 
         [0037]    An alternative means to prevent removal is illustrated in dashed lines in  FIG. 7 . In this alternative, the means to prevent removal comprises a groove or channel  110  formed in the end surface of the post  20 . When the valve assembly is installed, the ends  58  of the snap tabs  52   a ,  52   b  are designed to be disposed within the channel  110 . When the ends are disposed in the channel  110 , the ends  58  of the snap tabs cannot be deflected inwardly which would be necessary to achieve removal of the valve cover from the valve body. 
         [0038]    In addition, the interference fit between the valve assembly  30  and the post  20  is of such magnitude that if someone tries to remove the valve assembly  30 , the engineered weak point is designed to break at a lower force than the interference force. Therefore, attempted removal of the valve assembly will cause the valve body and/or the valve cover to break, thereby providing an indication that someone has tried to tamper with the valve assembly  30 . Means other than an interference fit can be used to secure the valve assembly in the post, for example an adhesive or a chemical weld. 
         [0039]    The valve assembly described herein may be embodied in other forms without departing from its spirit or characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.