Patent attributes
A piston seal assembly for a pipette includes an O-ring having radially inner and outer surfaces and axially separated first and second surfaces. A seal includes a radially extending rim portion having axially separated first and second surfaces and an axially extending sleeve portion forming an opening. A seat includes an axially extending indexing portion and a radially extending engagement portion forming an opening and having axially separated first and second surfaces. The seal is positioned such that the pipette piston extends through the opening and the radially inner surface of the sleeve portion slidably engages the piston. The seat is positioned such that the piston extends through the opening, the first and second surfaces of the engagement portion engage the second surface of the rim portion and an end of the spring, respectively, and the radially outer surface of the indexing portion engages the inner surface of the pipette body. The O-ring is positioned such that the sleeve portion of the seal extends axially through the opening of the O-ring, the radially inner surface of the O-ring engages the radially outer surface of the sleeve portion, the radially outer surface of the O-ring engages the radially inner surface of the indexing portion, the first surface of the O-ring engages a shoulder of the pipette body, and the second surface of the O-ring engages the first surface of the rim portion.
