Patents by Inventor Donald H. Duncan

Donald H. Duncan 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).

  • Methods and apparatus for delaminating sedimentary mica
    Patent number: 5797547
    Abstract: A superior grade of flake mica product may be produced by applying shear forces to sedimentary mica to delaminate it into flakes. Shear forces are applied by rotating a plurality of arcuate blades within a confined cylindrical chamber containing the mica, such that the mica is forced between an outer portion of each blade and the chamber. Each one of the arcuate blades is curved to define an end portion that is spaced from, and substantially concentric with, a portion of the cylindrical chamber.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: August 25, 1998
    Assignee: Duncan Technologies
    Inventor: Donald H. Duncan
  • Mica deliminator
    Patent number: 5137217
    Abstract: A mica plate delaminator has a delaminating cylindrical chamber with a flat disk mounted on a drive shaft at a 65 degree angle to the shaft. A screw feeder feeds material from a hopper into the delaminating chamber and the disc is rotated at 600-1200 rpm to force the mica back and forth over itself and the clearance between the disc and the housing to a discharge, delaminating the mica plates to small flakes.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: August 11, 1992
    Assignee: J.M. Huber Corporation
    Inventor: Donald H. Duncan
  • Mica delaminator
    Patent number: 5037034
    Abstract: A mica plate delaminator has a delaminating cylindrical chamber with a flat disk mounted on a drive shaft at a 65 degree angle to the shaft. A screw feeder feeds material from a hopper into the delaminating chamber and the disc is rotated at 600-1200 rpm to force the mica back and forth over itself and the clearance between the disc and the housing to a discharge, delaminating the mica plates to small flakes.
    Type: Grant
    Filed: January 2, 1990
    Date of Patent: August 6, 1991
    Assignee: J. M. Huber Corporation
    Inventor: Donald H. Duncan