STRUCTURES FOR PROVIDING A REMOVABLE CLOSURE

摘要

A membrane lid (10) with a surface (12) with a substantially triangular-shaped perimeter (14). The perimeter includes first, second and third corner portions (20a,20b,20c), wherein each corner portion is bisected by an imaginary line (18a,18b,18c). The membrane lid (10) further includes a projection (24) with a tab (26) and adapted to initially direct a lifting force to at least one of the corner portions (20a,20b,20c). The projection (24) either extends outwardly from the perimeter (14) such that the projection (24) is non-symmetrically disposed with respect to the imaginary line (18a,18b,18c) of any adjacent corner portion (20a,20b,20c), or the projection (24) extends non-continuously from an adjacent corner portion (20a,20b,20c) and is substantially symmetrically disposed with respect to said imaginary line. Containers (50) are also provided with a lip (54) having a substantially triangular-shaped horizontal cross-section. The lip (54) includes three corner portions (56) and three sides (58),wherein the sides (58) of the lip (54) are structured differently than the corner portions (56) of the lip (54).