Patents by Inventor Doud Roger Branham

Doud Roger Branham 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).

  • Hand-held micropipettor with improved accuracy of liquid volumes transferred
    Patent number: 4054062
    Abstract: A hand-held micropipettor having a construction to impede transfer of heat from a handle to a portion enclosing a piston chamber, and means for drawing room air along the piston to effect its cooling when the micropipettor is operated. A compressible piston seal is held in place with a retainer urged in an axial direction by a resilient element with an uniform force independent of the position of the piston.
    Type: Grant
    Filed: May 3, 1976
    Date of Patent: October 18, 1977
    Assignee: Oxford Laboratories Inc.
    Inventor: Doud Roger Branham
  • Hand-held micropipettor with improved pipette tip ejector
    Patent number: 4009611
    Abstract: A hand-held micropipettor having an improved tip ejector that is operable by the same thumb stroke of the user that operates a liquid transfer plunger therein. In one embodiment, the tip ejector has its own separate knob adjacent the liquid transfer plunger. In another embodiment, operation of the plunger itself causes a pipette tip to be ejected at the end of the liquid transfer plunger stroke.
    Type: Grant
    Filed: May 13, 1976
    Date of Patent: March 1, 1977
    Assignee: Oxford Laboratories Inc.
    Inventors: George Warren Koffer, Doud Roger Branham
  • Volume setting mechanism for fluid discharge devices
    Patent number: 3987934
    Abstract: A device for accurately dispensing a volume of fluid that is predetermined by limiting the outward travel distance of a plunger within a fluid chamber. The plunger limit stop is attached to a scale post having raised indicia lines and is adjustable therealong by a detent engagement wherein the limit stop is selectively positioned to engage one of a plurality of notches formed on the scale post between its volume indicia raised lines.
    Type: Grant
    Filed: August 16, 1974
    Date of Patent: October 26, 1976
    Assignee: Oxford Laboratories Inc.
    Inventors: Richard Dean Reed, Doud Roger Branham