Patent ID: 8597748

Claim:
A preform for making a plastic container, comprising: a longitudinal axis; a sidewall having an inner surface and an outer surface, said sidewall defining: a finish portion having at least one external thread defined thereon, said finish portion having a first sidewall thickness; a main body portion; an end cap, said end cap having a second side wall thickness, said second side wall thickness being not less than said first side wall thickness, an inner surface of the end cap being curved; and a transition portion between said end cap and said main body portion, wherein the inner surface of said sidewall that defines said transition portion is continuous with a proximal portion of the inner surface of the end cap and has a radius taken from the longitudinal axis, wherein the radius remains substantially constant along the transition portion; and a thickness of the sidewall that defines the transition portion increases from a distal end of the transition portion that joins the end cap to a proximal end of the transition portion that joins the main body portion.