Patents by Inventor Ydo N. Hoekstra

Ydo N. Hoekstra 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).

  • Method of checking the composition of multilayer units composed of sheetlike parts and apparatus for composing, and checking the composition of, such units
    Patent number: 5526939
    Abstract: An apparatus for verifying any of a plurality of predetermined compositions of multilayered units composed of stacked sheetlike parts passed in spaced succession by a checkpoint, including the steps of determining a first value according to a thickness of a first unit of a first predetermined composition; storing said first value as a reference value for said first predetermined composition; determining a second value according to a thickness of a successive unit intended to have said first predetermined composition; comparing said reference value with said second value; and rejecting said successive unit when said second value is outside a tolerance range around said reference value; wherein said first and second values are calculated from a plurality of measurements taken during at least one predetermined measuring interval along each of said first unit and said successive unit, respectively, at least one limit of said at least one measuring interval being related to the passage of a transverse edge of the
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: June 18, 1996
    Assignee: Hadewe B.V.
    Inventors: Ydo N. Hoekstra, Klaas Drenth
  • Method of checking the composition of multilayer units composed of sheetlike parts and apparatus for composing, and checking the composition of, such units
    Patent number: 5265733
    Abstract: A method for verifying any of a plurality of predetermined compositions of multilayered units composed of stacked sheetlike parts passed in spaced succession by a checkpoint, including the steps of determining a first value according to a thickness of a first unit of a first predetermined composition; storing the first value as a reference value for the first predetermined composition; determining a second value according to a thickness of a successive unit intended to have the first predetermined composition; comparing the reference value with the second value; and rejecting the successive unit when the second value is outside a tolerance range around the reference value; wherein the first and second values are calculated from a plurality of measurements taken during at least one predetermined measuring interval along each of the first unit and the successive unit, respectively, at least one limit of the at least one measuring interval being related to the passage of a transverse edge of the respective unit
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: November 30, 1993
    Assignee: Hadewe B.V.
    Inventors: Ydo N. Hoekstra, Klaas Dreuth