Patents by Inventor Guo Chen Liu

Guo Chen Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Pipette piston seal assembly
    Patent number: 6926867
    Abstract: 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.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: August 9, 2005
    Assignee: World Precision Instruments, Inc.
    Inventors: Su Yi Liu, Guo Chen Liu