Filter element

Claim 1

A FILTER ELEMENT COMPRISING (1) A NONRIGID FILTER MATERIAL FORMED IN A CLOSED CONFIGURATION; (2) A CORE SUPPORT FOR THE FILTER MATERIAL; AND (3) END PORTIONS RETAINING THE FILTER MATERIAL AND CORE SUPPORT IN JUXTAPOSED RELATIONSHIP, THE CORE SUPPORT COMPRISING A PLURALITY OF UNITARY CORE SUPPORT SECTIONS OF SUBSTANTIALLY RIGID SHEET MATERIAL HELD TOGETHER TO FORM THE CORE, EACH OF SAID SECTIONS INDIVIDUALLY DEFINING AN ARC PORTION WITHIN THE RANGE FROM ABOUT 45* TO ABOUT 180* OF THE CIRCUMFERENCE OF THE CORE SUPPORT, TOGETHER DEFINING 360* OF THE CIRCUMFERENCE OF THE CORE SUPPORT AND ENCLOSING A CENTRAL OPEN PASSAGE; THE CORE SUPPORT SECTIONS EACH HAVING A PLURALITY OF RAISED AND DEPRESSED PORTIONS, AND OPENINGS DISPOSED IN THE DEPRESSED PORTIONS FOR PASSAGE OF FLUID THERETHROUGH FROM THE OUTSIDE TO THE INSIDE OF THE CORE SUPPORT; THE RAISED PORTIONS BEING IN CONTACT WITH A PORTION OF THE FILTER MATERIAL, THE DEPRESSED PORTIONS HAVING EDGES MATCHING AND JOINING TO THE CORRESPONDING EDGES OF THE RAISED PORTIONS, AND BOTH THE RAISED AND DEPRESSED EDGES OF EACH CORE SECTION MATCHING AND ABUTTING THE CORRESPONDING RAISED AND DEPRESSED EDGES OF THE NEXT SUCCEEDING CORE SECTION, THE EDGES OF THE DEPRESSED PORTIONS BEING PROVIDED WITH FLANGES EXTENDING OUTWARDLY THEREFROM TO A DISTANCE AT MOST SUBSTANTIALLY EQUAL TO THE HEIGHT OF THE RAISED PORTIONS, THE FLANGES OF EACH CORE SECTION ABUTTING THE FLANGES OF THE NEXT SUCCEEDING SECTION.