Patent ID: 8839749

Claim:
A piston, comprising: a piston head; a piston pin support projecting from said piston head; and a mantle wall connected to said piston head, said mantle wall including two tubular pieces arranged concentrically relative to one another and connected to said piston head at a periphery of said piston head, and wherein said tubular pieces are an external tubular piece and an internal tubular piece disposed with a hollow space formed between said external and internal tubular pieces; an end region of said internal tubular piece remote from said piston head being widened and bearing against an inner surface of said external tubular piece and being connected to said external tubular piece by roll welding; and said internal tubular piece having a plurality of outwardly protruding bulged portions formed thereon and distributed about a circumference of said internal tubular piece, for connecting said internal and external tubular pieces to one another and spacing said internal and external tubular pieces from one another and forming a hollow space therebetween.