Filter bag for vacuum cleaners and collar therefor

Claim 1

A VACUUM CLEANER FILTER BAG COMPRISING A BAG BODY FORMED OF FILTER SHEET MATERIAL, SAID BODY HAVING AN OPENING DEFINED IN A WALL THEREOF, A UNITARY VALVE COLLAR MOUNTED ON AN EXTERIOR SURFACE OF THE BAG AND OVERLYING SAID OPENING, THE DIAMETER OF SAID COLLAR BEING GREATER THAN THE DIAMETER OF SAID OPENING, SAID COLLAR HAVING A SECURING PORTION WHICH ENCOMPASSES SAID OPENING AND IS SECURED TO SAID EXTERIOR SURFACE, AND A GASKET OVERLYING SAID SECURING PORTION AND SECURED THERETO, SAID COLLAR BEING FORMED OF A FLEXIBLE MATERIAL AND HAVING A PLURALITY OF SLITS EXTENDING RADIALLY OUTWARDLY FROM THE CENTER OF THE COLLAR TO DEFINE SLITTED PORTIONS WHICH ARE DEFLECTABLE FROM THE PLANE OF SAID COLLAR INTO SAID BAG OPENING IN RESPONSE TO AIR PRESSURE TO DEFINE A VAVLE OPENING IN COMMUNICATION WITH THE INTERIOR OF SAID BAG, SAID SLITTED PORTIONS BEING RETURNABLE TO SAID PLANAR DISPOSITION THEREOF IN THE ABSENCE OF AIR PRESSURE TO CLOSE SAID VALVE OPENING, SAID COLLAR VALVE BEING A PLASTIC MEMBER PROVIDED WITH CONCENTRIC CORRUGATIONS, AND EACH OF SAID RADIAL SLITS CUTTING THROUGH AT LEAST TWO OF SAID CORRUGATIONS.