Patent ID: 6454118
Filing Date: 2002-09-24
Classification: B21D,Y10S

Abstract:
A lid comprising:a closing upper wall (1) having an upper lip (3) on a perimeter thereof that projects above said upper wall (1) and a skirt (4) that extends below said upper wall (1); wherein said lip has reedings which are confined to an external sidewall and internal sidewall of said upper lip (3), said reedings being protrusions formed by cylindrically toothed indentations undulating together with an involute of radius R around the external sidewall and the internal sidewall; wherein the longitudinal axes of said protrusions are parallel to a central axis of said lid; said skirt (4) having a uniform inner diameter throughout a lower portion thereof; a diameter of the external surface of said upper lip (3) being smaller than the uniform internal diameter of said skirt; wherein a skirt (4) of each said lid in a stack of identical said lids engages substantially a full length of the external sidewall reedings of each said lid thereunder in the stack.