Patent ID: 7475631

Claim:
A piston assembly for a food extruder having a food reservoir that has a chamber and an inner surface, the piston assembly having a piston rod adapted for slidably extending into the chamber of the food reservoir and having a lower end; and a piston dish being circular, attached to the piston rod with a clearance between the lower end of the piston rod and the piston dish and having a lower segment having a top; a closed bottom; an outer surface having an inclined bottom edge; and a center; and multiple anti-cant protrusions being trapezoid, formed on and protruding out from the outer surface of the lower segment and adapted for facing, abutting and sliding on the inner surface of the food reservoir; an upper segment being hollow and formed with and protruding out from the outer surface of the lower segment; an annular groove formed in the outer surface of the lower segment adjacent to the upper segment; and a sealing ring mounted in the annular groove and adapted for slidably pressing against the inner surface of the food reservoir.