Abstract:
A fluid filter assembly prevents the filter from moving when fluid is not flowing through the filter. The filter assembly of the invention includes a mounting ring mountable in the filter opening. The mounting ring has a mounting interface, which includes an axially extending portion and a radially outwardly extending flange that has a diameter greater than the filter opening. A rib extends radially outwardly from and circumscribes the ring. The rib is seatable within an annular groove defined within the filter housing and circumscribing the filter opening. When the rib is positioned in the groove, the filter is releasably secured in the opening.

Description:
REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation of application Ser. No. 10/972,976, filed Oct. 25, 2004, the disclosure of which is hereby incorporated by reference, and is entitled to the filing date of that application. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]     This invention relates generally to fluid filters and, more particularly, to a filter assembly for a fluid filter.  
       BACKGROUND OF THE INVENTION  
       [0003]     Fluid filters have many manufacturing and processing applications. For example, fluid filters are often used in chemical applications, water applications, paints and coatings applications, plastics and resin applications, electronics and semiconductor applications, utilities and power generation applications, food and beverage applications and pharmaceutical applications.  
         [0004]     Conventional fluid filters include a filter housing which receives a removable filter element that is used to trap and remove particulates and other matter in the fluid between the filter&#39;s intake and outlet. The filter elements typically take the form of either a filter cartridge or a filter bag. Such elements are held in position within the housing and function sufficiently without incident during operation when fluid flows through the filter. Despite the individual circumstances of each application, however, the filter tends to move or float out of position in the housing when there is no fluid flowing through the filter. The force of the flow is necessary to hold conventional filters in position within the housing.  
         [0005]     There is a need, therefore, for an improved fluid filter that is removably securable in the housing so that it does not move during down time when fluid is not flowing through the filter and which can be conveniently removed for any reason and replaced when needed. The present invention is directed toward meeting this need.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention relates to a filter assembly for a fluid filter. The fluid filters of the type contemplated by the invention typically include a filter element, housing, an inlet and an outlet. Such filter assemblies generally include at least one housing section disposed between the inlet and the outlet communicating fluid from the inlet to the outlet, and the filter housing typically defines a filter opening. The filter assembly of the invention includes a mounting ring mountable in the filter opening. The mounting ring includes a mounting interface, and the mounting interface has an axially extending portion and a radially outwardly extending flange. The diameter of the flange is greater than the filter opening.  
         [0007]     In one aspect, the axially extending portion of the mounting ring includes an annular rib extending radially outwardly from the annular rib. The rib is seatable within an annular groove defined within the filter housing.  
         [0008]     In another aspect, the ring is contiguous with a portion of the filter housing surrounding the filter opening when the rib is seated within the groove.  
         [0009]     In yet another aspect, the rib circumscribes the axially extending portion of the mounting ring. The groove formed in said filter housing may likewise circumscribe the filter opening.  
         [0010]     One object of the present invention is to provide an improved fluid filter element that is removably securable in the housing so that it does not move when there is no fluid flow in the housing, and which can be conveniently removed for any reason and replaced when needed. Related objects and advantages of the present invention will be apparent from the following description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0012]      FIG. 1  is a sectional view of a fluid filter assembly in accordance with the present invention;  
         [0013]      FIG. 1A  is a detail view of the fluid filter assembly of  FIG. 1  showing the attachment of the cap;  
         [0014]      FIG. 1B  is a detail view of the fluid filter assembly of  FIG. 1  illustrating the method of attaching the filter element;  
         [0015]      FIG. 1C  is a detail view of the fluid filter assembly of  FIG. 1  similar to  FIG. 1B  and further illustrating the method of attaching the filter element;  
         [0016]      FIG. 2  is a top view of a modular housing section;  
         [0017]      FIG. 3  is a sectional view of the modular housing section taken along line  2 - 2  of  FIG. 2 ;  
         [0018]      FIG. 4  is a side view of a filter basket;  
         [0019]      FIG. 5  is an end view of the filter basket of  FIG. 4 ;  
         [0020]      FIG. 6  is a top view of the fluid filter cap;  
         [0021]      FIG. 7  is a sectional view of the cap taken along line  7 - 7  of  FIG. 6 ;  
         [0022]      FIG. 8  is a top view of the inlet housing section;  
         [0023]      FIG. 9  is a side view of the inlet housing section of  FIG. 8 ;  
         [0024]      FIG. 10  is a sectional view of the inlet housing section taken along line  10 - 10  of  FIG. 8 ;  
         [0025]      FIG. 11  is a top view of the outlet housing section;  
         [0026]      FIG. 12  is a sectional view of the outlet housing section taken along line  12 - 12  of  FIG. 11 ;  
         [0027]      FIG. 13  is a perspective view of a filter element; and  
         [0028]      FIG. 14  is a side view of another fluid filter assembly. 
     
    
       [0029]     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplification set out herein illustrates an embodiment of the invention, the embodiment disclosed below is not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise form disclosed.  
       DETAILED DESCRIPTION OF INVENTION  
       [0030]     A modular fluid filter assembly  20  in accordance with the present invention is shown in  FIG. 1 . Filter assembly  20  includes a filter housing  22  and a filter element  24 . Filter housing  22  includes an inlet housing section  26 , an outlet housing section  28  and modular housing sections  30 . In the illustrated embodiment, filter element  24  is a bag filter and is located within filter basket  32 . Cartridge filter elements may also be employed with alternative embodiments of the present invention. In the filter assembly  20  illustrated in  FIG. 1 , two modular housing sections  30  are disposed between inlet housing section  26  and outlet housing section  28 . An alternative number of modular housing sections  30  may also be used as discussed in greater detail below.  
         [0031]     An individual modular housing section  30  is shown in  FIGS. 2 and 3 . As can be seen in these two figures, modular housing section  30  is substantially cylindrical. An outwardly extending ring  34  is located on the outer surface of housing section  30  at the longitudinal midpoint of housing section  30 . Sidewalls  36  of housing section are slightly tapered, having a greater thickness near ring  34  and a smaller thickness near the opposing ends  38  of housing section  30 . The tapering of sidewalls  36  facilitates their release from a mold during manufacture of modular housing sections  30 . The interior surface of sidewalls  36  defines an interior cylindrical cavity  40 .  
         [0032]     Modular housing sections  30  are joined end-to-end and co-axially. In other words, ends  38  of adjacent housing sections  30  are abutted together during assembly of filter housing  22 . The ends  38  of adjacent housing sections  30  form a fluid tight seal therebetween and the abutted ends  38  may be joined by welding. For example, in the illustrated embodiment, housing sections  30  are formed of polypropylene with 20% glass fiber fill and adjacent housing sections  30  are welded together by interposing a hot plate between the two ends  38  to be joined and, after the ends  38  have been sufficiently heated, removing the plate and biasing the two ends  38  together so that they are fused together as they cool. Ends  38  may also be joined together by spin welding or any other suitable method for forming a fluid tight joint.  
         [0033]     As described above, opposing ends  38  of each modular housing section  30  have the same configuration. Thus, regardless of the number of modular housing sections  30  located between the inlet housing section  26  and the outlet housing section  28 , the joined housing sections  30  will have two opposing ends  38  that can be respectively joined to inlet housing section  26  and outlet housing section  28 . Inlet and outlet housing sections  26 ,  28  each have an assembly interface  42  that takes the form of a cylindrical wall defining an opening  44 . Assembly interfaces  42  have the same configuration as ends  38  and inlet and outlet housing sections  26 ,  28 . Inlet and outlet sections  26 ,  28  are also formed of polypropylene with 20% glass fiber fill. Consequently, the assembly interfaces  42  of inlet and outlet sections  26 ,  28  can be joined to an end  38  of a modular housing section  30  in the same manner as ends  38  of separate modular housing sections  30  are joined together.  
         [0034]     Inlet housing section  26  of assembly  20  is shown in  FIGS. 8, 9  and  10  and includes an access opening  46  located coaxially and opposite opening  44 . Inlet housing section  26  also includes a threaded inlet opening  48  that is joined to a fluid line to receive the fluid that is to be filtered by filter assembly  20 . As best seen in  FIGS. 8 and 9 , a camming interface for securing cap  56  to inlet housing section  26  includes a series of cam locking members  50  are located on the outer surface of generally cylindrical inlet housing section  26 . Cam locking members  50  include a circumferentially extending locking portion  52  and a longitudinally extending stop  54 . Cap  56  includes a plurality of cooperating cam locks  58  that extend circumferentially along the inner surface of cap  56 . Cam locks  58  each include an inclined surface  60  and a locking surface  62 . When mounting cap  56  to inlet housing section  26 , cam locks  58  fit between locking members  50  as cap  56  is longitudinally mounted on inlet housing section  26 . Rotation of cap  56  engages each inclined surface  60  with one of the locking members  50  on inlet housing section  26 . As cap  56  is rotated, locking surfaces  62  are rotated into engagement with locking portions  52  to tightly engage cap  56  with inlet housing section  26 . As cap  56  is further rotated, cam locks  58  engage stops  54  which thereby prevent the over-rotation of cap  56 .  
         [0035]     A V-shaped gasket  66  ( FIG. 1A ) is used to form a fluid tight seal between cap  56  and inlet housing section  26 . Gasket  66  is located between the inner radial surface  64  of inlet housing  26  that defines access opening  46  and cylindrical lip  68  located on cap  56 . Gasket  66  has an open end  70  that faces the interior volume of inlet housing section  26  so that the interior of gasket  66  is in fluid communication with the fluid within filter assembly  20 . Consequently, when pressurized fluid is present in filter assembly  20  the fluid will bias the two separate legs of gasket  66  apart and into sealing contact with interior surface  64  and outer radial surface of lip  68  respectively. Inlet housing section  26  includes a vent bore  67  at its upper rim which is sealed by gasket  66  when cap  56  is properly seated. If the cap is not properly seated, liquid will seep from bore  67  when the filter is filled to alert the user.  
         [0036]     Filter element  24  is secured by engagement with inlet housing section  26  near assembly interface  42 . Filter element  24  has a mounting ring  72  that is removably mounted to inlet housing section  26  in a snap fit engagement. Ring  72  defines a mounting interface that includes an outer radially extending flange  74  and a generally cylindrical section  76  having an outwardly extending annular rib  78  which may be segmented. Ring  72  also includes a second cylindrical mounting section  80  having a smaller diameter. Filter bag  82  is secured to mounting section  80 . In the illustrated embodiment, ring  72  is formed of polypropylene. Other materials, however, such as nylon, polyester or steel may also be used to form the mounting ring of a bag-type filter element.  
         [0037]     Filter bag  82  is a conventional non-woven felt filter bag. Such filter bags may be formed from fibers of a variety of different materials such as polyester, polypropylene, nylon, nomex, Teflon® or other suitable material as is well known to those having ordinary skill in the art. Filter bag  82  has an open end that is attached to mounting section  80  of ring  72  by ultrasonic welds  84 . Stitching or other suitable means may alternatively or additionally be employed to attach bag  82  to ring  72 . Bag-type filter elements suitable for use with the present invention are commercially available from Filter Specialists, Inc. having a place of business in Michigan City, Ind. For purposes of clarity, filter bag  82  is not shown in  FIG. 1 .  
         [0038]     When installing filter element  24  in filter housing  22 , filter bag  80  is inserted through access opening  46  and opening  44  into the interior volume  40  of modular housing sections  30  until mounting ring  72  engages inlet housing section  26  adjacent opening  44  to secure filter element  24  within assembly  20 . The snap-fit securement of mounting ring  72  is best seen in  FIGS. 1B and 1C .  FIG. 1B  illustrates mounting ring  72  immediately prior to its securement. As can be seen in  FIG. 1B , outer radial flange  74  forms an acute angle with cylindrical section  76  and as axially-extending portions  80 ,  76  of ring  72  are inserted further into opening  44 , radial flange  74  tightly engages inclined shoulder surface  86  which surrounds opening  44 . An annular groove  88  is located within opening  44  and rib  78  is seated within groove  88  to secure mounting ring  72  in place. As illustrated in  FIG. 1C , the seating of rib  78  within groove  88  forces outer radial flange  74  relatively upwardly as it engages shoulder surface  86  to thereby form a fluid tight seal between flange  74  and shoulder surface  86 . The dashed line  74   a  shown in  FIG. 1C  illustrates the position of radial flange  74  in an unbiased condition.  
         [0039]     Ring  72  may also be provided with internal handles (not shown) that extend generally diametrically across ring  72  to allow ring  72  to be more easily flexed radially inwardly during insertion and removal of ring  72 . Such handles are disclosed in U.S. Pat. No. 4,669,167 which is hereby incorporated herein by reference.  
         [0040]     A reticulated filter basket  32  may optionally be employed with the present invention when using a bag-type filter element. Filter basket  32  has a length that corresponds to the length of the filter bag and is used to prevent the filter bag from engaging the interior surface of the filter housing during filtering operations. Filter basket  32  is positioned within the filter volume defined by modular housing sections  30  and rests upon ribs  90  located within outlet housing section  28 . Filter basket  32  has a generally perforated structure defining fluid openings  92  over the majority of its surface area as best seen in  FIGS. 4 and 5  with protrusions  94 .  
         [0041]     During filtering operations, fluid enters filter assembly  20  through inlet  48  and then passes through ring  72  and opening  44  and into filter bag  82 . The fluid then passes through bag  82 . As the fluid passes through bag  82 , the fluid is filtered and particulates removed from the fluid. The filtered fluid then passes through openings  92  in filter basket  32 . The filtered fluid flows between filter basket  32  and the interior surface of filter housing  22  towards threaded outlet opening  96  in outlet housing section  28  where it exits filter assembly  20 .  
         [0042]     Outlet housing section  28  is shown in  FIGS. 11 and 12  and includes three feet  98  for supporting filter assembly  20  in a vertical orientation. Ribs  90  located within the interior volume of outlet housing section  28  are best seen in  FIG. 11 .  
         [0043]     A bag-type filter element  24  is illustrated in  FIG. 13 . In the illustrated filter element  24 , filter bag  82  has a length that corresponds to the filter cavity  40  defined by the use of two modular housing sections  30  as depicted in the fluid filter assembly  20  of  FIG. 1 . Dashed lines  82   a  and  82   b  indicate the length of two alternatively sized filter elements. In each case, the differently sized bag-type filter elements would employ a mounting ring  72  having the same configuration whereby each of the bags could be mounted, using the snap-fit securement method described above, in an inlet housing  26 .  
         [0044]     As described above, modular housing sections  30  each have the same configuration and are coaxially securable to thereby define a filter cavity  40  having a length that varies depending upon the number of modular housing sections  30  joined together. Thus, when it is desired to manufacture a fluid filter that employs a filter element with a bag having a length  82   a , the filter housing is constructed using only a single modular housing section  30  as depicted in  FIG. 14 . The fluid filter assembly  20   a  shown in  FIG. 14  thereby defines a filter cavity  40  having a length suited for use with the selected filter element. Similarly, when it is desired to manufacture a fluid filter that employs a filter element with a bag having a length  82   b , the filter housing is constructed using three modular housing sections  30  to thereby define a filter cavity  40  having an appropriate length.  
         [0045]     The present invention thereby facilitates the efficient manufacture of filter housings for a variety of differently sized filter elements. Each of the filter housings will employ an inlet housing section  26 , in which each of the different filter elements can be removably mounted, an outlet housing section  28 , and one or more modular housing sections  30 . The number of modular housing sections being determined by the size of the filter element with which the filter housing is intended to be used.  
         [0046]     While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.