Cup and apparatus and method for making it

Claim 1

A cup adapted to use with a warming unit, comprising a plastic body having an open mouth and a base part defining an opening, a radially outwardly extending flange around said base part, said flange having axially spaced, radially extending upper and lower planar surfaces substantially parallel to one another, a metal base closure of a metal having a lower coefficient of expansion than said plastic, said closure having a bottom wall and a rim around said bottom wall and extending higher than the upper surface of the said flange, said closure bottom wall extending continuously over said opening and beyond a radially outer edge of said flange parallel with said body flange lower radial planar surface, and an annular gasket between and in engagement with an upper surface of the bottom wall of said closure and said lower surface of said flange, said closure rim having staked over portions around its upper edge engaging said upper radially extending flange surface, the staked over portions thereof that engage said upper radially extending surface defining a plane substantially parallel with said bottom wall along said gasket and extending over said upper surface of said flange a distance greater than any anticipated distance of contraction or expansion of said flange relative to said staked portion of said closure rim upon repeated cycling of heating and cooling whereby said plastic flange can move radially, sandwiched between said bottom wall and said staked over portions, while maintaining its dimensional integrity axially between said bottom wall and said staked over portions.