Patent ID: 6588321
Filing Date: 2003-07-08
Classification: B23P,F04B,F16J

Abstract:
A closed cavity piston comprising:an elongated piston body including a closed end and an open end, the open end having an entrance opening therein and a cavity extending inwardly from the entrance opening so as to define a bottom wall adjacent the closed end and an outer wall terminating in a longitudinally facing rim at the open end adjacent the entrance opening; a piston cap formed separately from the piston body and including an elongated stem having a central longitudinal axis, opposite first and second ends, and a head at the first end, the head protruding outwardly from the stem in a direction transverse to the longitudinal axis of the stem; the stem of the piston cap being attached to the bottom wall of the piston body; and the head of the piston cap of being sufficient size and being attached to the longitudinally facing rim of the piston body so as to cover the entrance opening and sealingly enclose the interior cavity.