Patent ID: 7621212
Filing Date: 2009-11-24
Classification: A47J

Abstract:
1. A piston of an automatic machine for infusion of beverages, the piston being associated with a duct allowing the passage of liquid intended for infusion of said beverage and comprising: a piston head divided into two parts connected together and axially movable relative to each other so that said two piston parts are adapted to approach each other when an axially directed thrust is applied to said piston, and wherein said duct is an axial duct of said piston; an annular gasket housed between said two piston parts and radially expanding when an axially directed thrust is applied to said piston so as to make said two piston parts approach each other, the elastic resistance of said gasket keeping said two piston parts spaced apart when no axial thrust is applied onto the piston wherein said gasket ensures liquid tightness between said two piston parts both when said piston it is not submitted to an axial thrust, and when the piston is submitted to an axial thrust; and a circumferential seat for receiving said annular gasket formed between said two piston parts, wherein said seat includes;