Filter assembly

Abstract

A fuel filter assembly includes a header and a can-shaped housing removeably attached to the header. The can-shaped housing has an upper rim portion provided with a plurality of notches therein. A filter unit has an upper end cap provided with a plurality of tabs extending from the periphery and positioned within the notches of the housing. The spacing of the notches about the axis of the housing must be the same as the spacing of the tabs about the axis of the filter unit to permit the filter unit and housing to be properly assembled, thereby preventing the use of an incorrect filter unit within the housing. Additionally, the header has a plurality of key slots that receive the tabs on the filter unit. The spacing of the key slots and tabs must be the same to permit the housing and received filter unit to be properly connected to the header.

1 . A fuel filter assembly comprising:
 a header;   a housing removeably attached to said header, said housing including an upper edge portion having a plurality of notches therein; and   a cartridge unit within said housing, said cartridge unit having an upper end cap provided with a plurality of tabs extending from the periphery thereof, said tabs being positioned in said notches in said housing.   
     
     
         2 . The fuel filter assembly of  claim 1  wherein said tabs include a finger portion at the ends thereof positioned against the outer surface of the housing. 
     
     
         3 . The fuel filter assembly of  claim 2  wherein there are at least three tabs. 
     
     
         4  The fuel filter assembly of  claim 3  wherein said housing has an axis, said notches have a predetermined angular spacing about said housing axis, and said tabs have an angular spacing coincident with said angular spacing of said notches. 
     
     
         5 . The fuel filter assembly of  claim 1  wherein said header includes radially protruding features and said housing includes a circumferential rim on its outer surface, and said filter assembly further including a locking ring for engaging said features and said rim for locking said housing to said header. 
     
     
         6 . The fuel filter assembly of  claim 5  wherein said housing comprises two parts, the first part being an upper cap portion having said notches therein and said second part being a bowl-shaped lower portion, said first and second parts being connected by a rolled seam, said rolled seam providing said circumferential rim on said housing. 
     
     
         7 . The fuel filter assembly of  claim 2  wherein said header includes a downwardly extending skirt having an inner surface and a plurality of circumferentially spaced key slots in the inner surface, said key slots being equal in number to said tabs and having the same circumferential spacing as said tabs and being adapted to receive said tabs when said housing is attached to said header. 
     
     
         8 . The fuel filter assembly of  claim 7  wherein said header has a rim extending around the upper portion of the inside surface of said skirt, said key slots being formed in said rim. 
     
     
         9 . The fuel filter assembly of  claim 7  wherein said skirt has an outer surface, said outer surface having a plurality of lugs thereon, and further including a locking ring for attaching said housing to said header, said locking ring having a portion in engagement with said housing and an upper surface with a plurality of slots extending downwardly therefrom in the internal surface that communicate with a slanted internal ramp thereof, each said slot aligned to receive one of said lugs therein to permit said locking ring to be moved upwardly and rotated with the keying lugs riding along the slanted ramp. 
     
     
         10 . The fuel filter assembly of  claim 9  wherein said header has a fuel inlet and a fuel outlet, said fuel inlet communicating with the interior of said header at a point above cartridge unit, said upper end cap having a periphery excluding said tabs that is spaced from said upper edge portion of said housing to form a gap for fuel to flow into the interior of said housing. 
     
     
         11 . The fuel filter assembly of  claim 10  wherein said filter unit has a center aperture and said header has a center post extending into said aperture, said fuel outlet connected to the center aperture by a passageway extending though said center post. 
     
     
         12 . The fuel filter assembly of  claim 1  wherein said housing is molded from plastic or metal. 
     
     
         13 . A filter unit for a fuel filter assembly comprising:
 a filter element having a generally cylindrical profile;   upper and lower end caps at the ends of said filter element, said upper end cap having a plurality of tabs extending from the peripheral edge thereof, the distal end of each of said tabs having a down-turned finger portion spaced from the filter element to form gap between an inside surface of said down-turned finger portion and the filter element.   
     
     
         14 . The filter unit of  claim 13  wherein there are at least three tabs. 
     
     
         15 . The filter unit of  claim 13  wherein the tabs have a predetermined spacing about the axis of the filter element. 
     
     
         16 . The filter unit of  claim 13  wherein said filter element has a center aperture and said upper end cap has an aperture coaxial with the center aperture, and further including a grommet mounted in the aperture in said upper end cap. 
     
     
         17 . A filter cartridge assembly for connection to a header of a fuel filter assembly comprising:
 a housing having an upper edge portion, said upper edge portion having a plurality of notches therein spaced about an axis of the housing,   a filter unit including a filter element having a generally cylindrical outer profile and an upper and lower end cap, said upper end cap having a plurality of tabs extending from an outer periphery thereof, said tabs being equal in number to said notches in said housing and being spaced about the axis of said filter unit in the same configuration as the spacing of said notches about the axis of said housing, said tabs being positioned in said notches.   
     
     
         18 . The filter cartridge assembly of  claim 17  wherein each of said tabs has a down-turned portion at its end, said down-turned portion positioned against an outside surface of the housing. 
     
     
         19 . The filter cartridge assembly of  claim 18  wherein there are at least three notches. 
     
     
         20 . The filter cartridge assembly of  claim 18  wherein the periphery of said upper end cap excluding said tabs is radially spaced from said upper edge portion of said housing to form a gap between the upper end cap and the housing.