Patents by Inventor James W. Derrick

James W. Derrick 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).

  • Patent number: 4857176
    Abstract: A molded polyurethane vibratory screen including a body having opposite side edge portions, upper and lower edge portions, an upper surface and a lower surface, a plurality of major and minor substantially parallel ribs extending between the upper and lower edge portions and substantially parallel to the side edge portions, dividing strips extending between the major and minor ribs to define screen openings therebetween, aramid fibers extending between the side edge portions and through the dividing strips to provide tensile strength to the dividing strips, and upper triangular cross section portions formed integrally with the major and minor ribs and extending above the upper surface of the screen to direct foreign matter laterally toward the screen openings. The dividing strips are preferably in the cross-sectional form of an inverted trapezoid, or in a form having an upper portion in the shape of an inverted trapezoid and the lower portion in the shape of a rectangle.
    Type: Grant
    Filed: June 17, 1988
    Date of Patent: August 15, 1989
    Assignee: Derrick Manufacturing Corporation
    Inventors: James W. Derrick, L. Charles Matsch
  • Patent number: 4819809
    Abstract: A molded polyurethane vibratory screen including a body having opposite side edge portions, upper and lower edge portions, an upper surface and a lower surface, a plurality of major and minor substantially parallel ribs extending between the upper and lower edge portions and substantially parallel to the side edge portions, dividing strips extending between the major and minor ribs to define screen openings therebetween, aramid fibers extending between the side edge portions and through the dividing strips to provide tensile strength to the dividing strips, and upper triangular cross section portions formed integrally with the major and minor ribs and extending above the upper surface of the screen to direct foreign matter laterally toward the screen openings.
    Type: Grant
    Filed: January 1, 1987
    Date of Patent: April 11, 1989
    Assignee: Derrick Manufacturing Corporation
    Inventor: James W. Derrick
  • Patent number: 4575421
    Abstract: A non-clogging and wear-reducing screen assembly for a vibrating screening machine including a substantially rigid plate having upper and lower sides and having first and second pairs of opposite edges, attachment members formed integrally with a plate on a first pair of opposite edges for attachment to a vibrating screening machine, a plurality of spaced openings throughout the substantially rigid plate and extending in both directions between the first and second pairs of the opposite edges, borders on the plate surrounding the openings, a supporting screen on the upper side of the plate, first and second superimposed contiguous abutting screens overlying the supporting screen, and adhesive firmly securing the supporting screen and the first and second screens to the borders of the openings.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: March 11, 1986
    Assignee: Derrick Manufacturing Corporation
    Inventors: James W. Derrick, Robert G. Derrick