Filter Element, Filter Device and Method for Producing a Filter Element

Abstract

Filter element ( 1 ) has opposing end sections ( 3 A, 3 B) of a filter material sheet ( 2 ) that are connected to each other in a fluid-tight manner, wherein a molded or extruded plastic casing ( 5 ) encloses the end edges ( 4 A, 4 B) of the end sections ( 3 A, 3 B). A method for producing a corresponding filter element ( 1 ) includes the encasing of opposing end edges ( 4 A, 4 B) of end sections ( 3 A, 3 B) of a filter material sheet ( 2 ) with a plastic casing ( 5 ) so as to form a continuous bellows.

1 . A filter element comprising:
 a sheet of filter material having end sections ( 3 A,  3 B) at opposing ends of the sheet, said end opposing end sections ( 3 A,  3 B) each having a terminal edge ( 4 A,  4 B) of said filter material sheet, said terminal edges each having an overall length (L);   wherein said end sections of said filter material sheet are overlaid against each other;   molded or extruded elongated plastic casing ( 5 ) arranged on and covering at least a portion of said length of said terminal edges, securing said end sections and said terminal edges together;   wherein said end sections are connected fluid-tightly with each other.   
     
     
         2 . The filter element according to  claim 1 , wherein
 said elongated plastic casing ( 5 ) completely encloses the terminal edges ( 4 A,  4 B) across entire overall length (L) of said terminal edges ( 4 A,  4 B).   
     
     
         3 . The filter element ( 1 ) according to  claim 1 , wherein
 said plastic casing ( 5 ) is formed directly on said terminal edges ( 4 A,  4 B).   
     
     
         4 . The filter element ( 10 ) according to  claim 1 , wherein
 said filter material sheet ( 2 ) includes a plurality of zig-zag folds and is formed into a circumferentially closed endless folded bellows.   
     
     
         5 . The filter element ( 1 ) according to  claim 1 , wherein
 said filter material sheet includes a plurality of overlaid layers ( 2 A,  2 B).   
     
     
         6 . The filter element according to  claim 2 , wherein
 said plastic casing ( 5 ) is formed directly on said terminal edges ( 4 A,  4 B);   wherein said filter material sheet ( 2 ) includes a plurality of zig-zag folds and is formed into a circumferentially closed endless folded bellows;   
     
     
         7 . The filter element according to  claim 6 , wherein
 said filter material sheet includes a plurality of overlaid layers ( 2 A,  2 B).   
     
     
         8 . A filter device ( 11 ) comprising:
 a filter element according to  claim 6 ;   an upper and a lower end cover ( 12 , 13 ) secured onto axially opposing ends of said circumferentially closed endless folded bellows; and   wherein at least one of said covers includes an opening ( 17 ) through which fluid enters or exits an interior of said circumferentially closed endless folded bellows.   
     
     
         9 . The filter device ( 11 ) according to  claim 8 , wherein
 said plastic casing ( 5 ) comprises the same material as said upper and the lower cover ( 12 ,  13 ).   
     
     
         10 . The filter device ( 11 ) according to  claim 9 , wherein
 said filter device is an operating medium filter, a fuel filter, an air filter, or a passenger compartment filter for a motor vehicle.   
     
     
         11 . A method for producing a filter element comprising:
 providing an injection molding tool having a cavity for molding a plastic casing;   providing a sheet of filter material having end sections at opposing ends of the sheet, said opposing end sections each having a terminal edge, said terminal edges have an overall length;   forming said sheet into a circumferentially closed endless bellows;   arranging said terminal edges in said cavity said that said opposing end sections are overlaid;   injection molding or extruding a plastic casing directly onto said terminal edges of said end sections of a filter material sheet, encloses said terminal edges across at least a portion of said overall length of said terminal edges, wherein said plastic casing secured said end sections are fluid-tightly together.   
     
     
         12 . The method of  claim 11 , wherein
 in said arranging step, said end sections at placed flat against each other.   
     
     
         13 . The method of  claim 11 , wherein before said forming step said method further comprises:
 folding said sheet into a plurality of zig-zag folds, said folds aligned parallel to each other and parallel to said terminal edges;   wherein in said forming step, said circumferentially closed endless bellows is a circumferentially closed endless folded bellows.   
     
     
         14 . The method of  claim 11 , wherein
 in said injection molding step, said terminal edges are completely enclosed and embedded within said plastic casing along entire overall length.   
     
     
         15 . The method of  claim 11 , wherein
 said injection molding step, said end sections are pressed against each other while molding said casing.   
     
     
         16 . The method of  claim 15 , wherein
 in said injection molding step, said injection molding tool or a press separate from said injection molding tool presses said end sections against each other.