Filter with efficiently sealed end

Abstract

A filter element has a resiliently compressible end cap at a first axial end sealing the filter and providing sealed engagement with a flow tube.A filter assembly comprising a filter media element having a first end and a second end, a first end cap disposed at the first end, and a second end cap disposed at the second end. The filter media element is shaped to form a hollow interior extending from the first end to the second end. The hollow interior defines an inner boundary of the element and the outer surface of the element defines an outer boundary. The second end cap covers both the filter media element and the hollow interior at the second end.

1. A filter element comprising pleated filter media having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, said loop having a hollow interior extending along a given axis, wherein fluid flows axially in said hollow interior, said filter element having first and second axial ends, said first axial end being open and providing an axial flow passage therethrough along said axis communicating with said hollow interior, a resiliently compressible end cap at said first axial end covering said inner and outer pleat tips and spanning radially between said inner and outer perimeters, a flow tube communicating with said hollow interior and extending along said axial flow passage and engaging said end cap, wherein said flow tube at said engagement with said end cap has an inner perimeter greater than said inner perimeter defined by said inner pleat tips, and comprising in combination a second end cap at said second axial end of said filter element covering said inner and outer pleat tips and spanning radially between said inner and outer perimeters and also spanning said hollow interior and closing said second axial end of said filter element. 
     
     
       2. The filter element according to  claim 1  wherein said inner perimeter of said flow tube at said engagement with said end cap is less than said outer perimeter defined by said outer pleat tips. 
     
     
       3. The filter element according to  claim 2  wherein said end cap has a first section extending radially inwardly from said outer perimeter defined by said outer pleat tips, and has a second section extending radially outwardly from said inner perimeter defined by said inner pleat tips, said first and second sections meeting at a junction defining a step facing radially toward and engaging said flow tube. 
     
     
       4. The filter element according to  claim 3  wherein said step has a first axial length, said flow tube has a tubular portion extending axially along said step, said tubular portion having an inner axial end axially facing said first axial end of said filter element, and said flow tube has a flange portion extending radially from said tubular portion and facing said first axial end of said filter element and axially spaced from said inner axial end of said tubular portion by a second axial length less than said first said axial length. 
     
     
       5. The filter element according to  claim 3  wherein said end cap has a first axial thickness at said first section at said outer perimeter defined by said outer pleat tips, a second axial thickness at said first section at said step, a third axial thickness at said second section at said step, and a fourth axial thickness at said second section at said inner perimeter defined by said inner pleat tips, and wherein said second axial thickness is greater than said third axial thickness. 
     
     
       6. The filter element according to  claim 5  wherein said first axial thickness is greater than said fourth axial thickness. 
     
     
       7. The filter element according to  claim 5  wherein said first axial thickness is less than said second axial thickness. 
     
     
       8. The filter element according to  claim 5  wherein said third and fourth axial thicknesses are substantially the same. 
     
     
       9. The filter element according to  claim 1  comprising a housing containing said filter element, said housing having an end wall axially facing said first axial end of said filter element, and wherein said flow tube is part of said end wall. 
     
     
       10. The filter element according to  claim 1  wherein fluid flows laterally radially through said filter element between said outer and inner perimeters, and flows axially in said hollow interior. 
     
     
       11. A filter element comprising a closed loop filter media member having a hollow interior extending along a given axis, wherein fluid flows axially in said hollow interior, said filter element having first and second axial ends, said first axial end being open and providing an axial flow passage therethrough along said axis communicating with said hollow interior, a resiliently compressible end cap at said first axial end, a flow tube communicating with said hollow interior and extending along said axial flow passage, said flow tube having a tubular portion engaging said end cap and forming a seal therewith, said tubular portion being cylindrical, said filter media member being non-cylindrical. 
     
     
       12. The filter element according to  claim 11  wherein said filter media member is elliptical. 
     
     
       13. The filter element according to  claim 11  wherein said end cap has a first section extending radially inwardly from an outer perimeter, and has a second section extending radially inwardly from said first section to an inner perimeter, said first and second sections meeting at a junction defining a step, said first section having said outer perimeter and having an inner perimeter at said step, said second section having an outer perimeter at said step and having said inner perimeter communicating with said hollow interior, said outer perimeter of said first section being non-cylindrical, said inner perimeter of said first section being cylindrical, said step being cylindrical, said outer perimeter of said second section being cylindrical. 
     
     
       14. The filter element according to  claim 13  wherein said cylindrical tubular portion engages said end cap at said cylindrical step. 
     
     
       15. The filter element according to claim wherein said inner perimeter of said second section is non-cylindrical. 
     
     
       16. The filter element according to  claim 13  wherein said filter media member and said outer perimeter of said first section of said end cap are elliptical and have a radially extending major axis and a radially extending minor axis, wherein the radial extension of said first section of said end cap along said major axis between said outer perimeter of said first section of said end cap and said step is greater than the radial extension of said first section of said end cap along said minor axis between said outer perimeter of said first section of said end cap and said step, and wherein the radial extension of said second section of said end cap along said minor axis between said step and said inner perimeter of said second section of said end cap is greater than the radial extension of said o second section of said end cap section along said major axis between said step and said inner perimeter of said second section of said end cap. 
     
     
       17. The filter element according to  claim 11  wherein said filter media member comprises pleated filter media having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, said loop having said hollow interior extending along said given axis. 
     
     
       18. A filter comprising pleated filter media having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, said loop having a hollow interior extending along a given axis, wherein fluid flows axially in said hollow interior, said filter having first and second axial ends, said first axial end being open and providing an axial flow passage therethrough along said axis communicating with said hollow interior, a resiliently compressible first end cap at said first axial end covering said inner and outer pleat tips and spanning radially between said inner and outer perimeters, a second end cap at said second axial end of said filter covering said inner and outer pleat tips and spanning radially between said inner and outer perimeters and also spanning said hollow interior and closing said second axial end of said filter, and an outer liner circumscribing said filter. 
     
     
       19. The filter according to  claim 18  wherein said outer liner circumscribes said filter at at least one of said pleated filter media and said first end cap. 
     
     
       20. The filter according to  claim 19  wherein said outer liner circumscribes said filter at said pleated filter media. 
     
     
       21. The filter according to  claim 20  wherein said outer liner circumscribes the entire said pleated filter media from said first axial end to said second axial end. 
     
     
       22. The filter according to  claim 19  wherein said outer liner circumscribes said filter at said first end cap. 
     
     
       23. The filter according to  claim 22  wherein said outer liner circumscribes a portion of said first end cap. 
     
     
       24. The filter according to  claim 19  wherein said outer liner circumscribes said filter at both of said pleated filter media and said first end cap. 
     
     
       25. The filter according to  claim 24  wherein said outer liner is a single one- piece member.   
     
     
       26. The filter according to  claim 18  wherein said first end cap has a first section extending radially inwardly from said outer perimeter defined by said outer pleat tips, and has a second section extending radially outwardly from said inner perimeter defined by said inner pleat tips, said first and second sections meeting at a junction defining a step. 
     
     
       27. The filter according to  claim 26  wherein said first end cap has a first axial thickness at said first section at said outer perimeter defined by said outer pleat tips, a second axial thickness at said first section at said step, a third axial thickness at said second section at said step, and a fourth axial thickness at said second section at said inner perimeter defined by said inner pleat tips, and wherein said second axial thickness is greater than said third axial thickness. 
     
     
       28. The filter according to  claim 27  wherein said first axial thickness is greater than said fourth axial thickness. 
     
     
       29. The filter according to  claim 27  wherein said first axial thickness is less than said second axial thickness. 
     
     
       30. The filter according to  claim 27  wherein said third and fourth axial thicknesses are substantially the same. 
     
     
       31. The filter according to  claim 18  wherein said first end cap is configured to receive a flow tube communicating with said hollow interior and extending along said axial flow passage and engaging said first end cap, wherein said flow tube at said engagement with said first end cap has an inner perimeter greater than said inner perimeter defined by said inner pleat tips, wherein said first end cap bears radially between said outer liner and said flow tube. 
     
     
       32. The filter according to  claim 31  wherein said outer liner has at least a portion circumscribing said filter at and extending axially into said first end cap. 
     
     
       33. The filter according to  claim 18  wherein said outer liner has a first section circumscribing said pleated filter media at said outer pleat tips, and a second section extending into said first end cap. 
     
     
       34. The filter according to  claim 33  wherein said outer liner is a unitary one- piece member, and said second section extends integrally from said first section.