Patents by Inventor John J. Bradshaw

John J. Bradshaw 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 preparing gypsum products
    Patent number: 5575844
    Abstract: The invention provides a method of making gypsum products such as plasterboard from foamed gypsum plaster slurry. The method uses a first mixing chamber 10 containing a high speed rotor 14 and inlets 18, 19 for gypsum plaster and water. The initial dispersion of gypsum plaster and water foamed in the first chamber passes directly and continuously into a second chamber 25 containing a low speed rotor 29. Preformed foam is introduced into the second chamber through an inlet 33, and the foamed slurry product leaves the second chamber through an outlet 34, to be formed into plasterboard.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 19, 1996
    Assignee: BPB Industries Public Limited Company
    Inventor: John J. Bradshaw
  • Mixer
    Patent number: 5484200
    Abstract: The invention provides apparatus for use in the preparation of gypsum products such as plasterboard from foamed gypsum plaster slurry. The apparatus comprises a first mixing chamber 10 containing a high speed rotor 14 and inlets 18, 19 for gypsum plaster and water. The initial dispersion of gypsum plaster and water foamed in the first chamber passes directly and continuously into a second chamber 25 containing a low speed rotor 29. Preformed foam is introduced into the second chamber through an inlet 33, and the foamed slurry product leaves the second chamber through an outlet 34, to be formed into plasterboard.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: January 16, 1996
    Assignee: BPB Industries Public Limited Company
    Inventor: John J. Bradshaw