Dispenser closure

Claim 1

A CONTAINER CLOSURE COMPRISING A RESILIENTLY DEFORMABLE CUP-SHAPED MEMBER HAVING A TOP WALL AND A SIDE WALL, AND A RELATIVELY RIGID COLLAR ROTATABLY MOUNTED ON THE EXTERIOR OF SAID CUP-SHAPED MEMBER WITH A SIDE WALL PORTION SLIDABLY BEARING AGAINST THE OUTER SURFACES OF SAID SIDE WALL OF SAID CUP-SHAPED MEMBER, SAID COLLAR SIDE WALL PORTION DEFINING A GENERALLY ELLIPTICAL APERTURE HAVING A PERIPHERAL LENGHT SUBSTANTIALLY EQUAL TO THE PERIPHERAL LENGHT OF THE COOPERATING OUTER SURFACE OF SAID CUP-SHAPED MEMBER, SAID TOP WALL HAVING THEREIN A SYMMETRICALLY POSITIONED DISPENSING APERTURE OF GENERALLY DOUBLE CONVEX CROSS SECTION IN THE OPEN POSITION AND PROVIDING SUBSTANTIALLY SYMMETRICAL, ARCUATE SIDES DEFINED BY A COMMON CHORD SO AS TO INTERSECT IN SHARP CORNERS AT THE ENDS OF THE LONG DIMENSION OF SAID APERTURE, THE WIDE DIMENSION OF SAID APERTURE IN THE OPEN POSITION BEING NO GREATER THAN THE DIFFERENCE BETWEEN THE DIMENSION OF SAID CUPSHAPED MEMBER COOPERATING OUTER SURFACE TO WHICH SAID WIDE DIMENSION IS PARALLEL AND THE MINOR AXIS OF SAID ELLIPTICAL APERTURE, SAID COLLAR BEING ROTATABLE FROM A POSITION WHEREIN THE MAJOR AXIS OF SAID APERTURE IS SUBSTANTIALLY ALIGNED WITH SAID WIDE DIMENSION TO PROVIDE THE OPEN POSITION OF SAID APERTURE TO A POSITION WHEREIN SAID MINOR AXIS OF SAID ELLIPTICAL APERTURE IS SUBSTANTIALLY ALIGNED WITH SAID WIDE DIMENSION TO DEFORM THE MATERIAL OF SAID TOP WALL AND CLOSE SAID DISPENSING APERTURE, SAID COLLAR AND CUP-SHAPED MEMBER HAVING INTERENGAGING MEANS SUBSTANTIALLY PREVENTING INADVERTENT RELATIVE AXIAL MOVEMENT THEREOF.