Patent ID: 6508161
Filing Date: 2003-01-21
Classification: A63H

Abstract:
A balloon hand pump operated by a reciprocating motion of a piston, the pump comprising:a cylinder having an axis of elongation; a piston axially reciprocal within the cylinder; a protruding structure formed at least at one location on the inside of an upper portion of the cylinder for preventing the piston from coming out of the cylinder; and a piston shaft coupled to the piston, the piston shaft having a cross-sectional configuration such that at least a portion of the outer surface of the piston shaft contacts the inner surface of the cylinder, to thereby prevent the piston shaft from becoming eccentric, and such that a portion of the outer surface of the piston shaft is spaced from the inner surface of the cylinder and axially aligned with the protruding structure for ensuring the reciprocating motion of the piston by avoiding abutment of the piston shaft with the protruding structure.