Patents by Inventor John H. Craig

John H. Craig 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: 5624182
    Abstract: An automatic cementing system and method are disclosed for precisely controlling the density of a slurry during a continuously mixed cement application. The system includes an input water line and a dry cement hopper for supplying water and dry cement, respectively, to a mixing chamber. The mixing chamber includes two chambers, Chamber A and Chamber B, for thoroughly mixing the water and cement together to form a cement slurry. Chamber B includes a level sensor for measuring the change in slurry level. The input line includes a pump for supplying the water to the mixing chamber, and a flow meter for measuring the rate at which the water is supplied. Similarly, the hopper includes a rotary valve for regulating the rate at which the dry cement is supplied to the mixing chamber and a speed sensor for measuring the speed of the rotary valve. A discharge line with a discharge pump and a discharge flow meter receives and discharges cement slurry.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: April 29, 1997
    Assignee: Stewart & Stevenson Services, Inc.
    Inventors: Michael P. Dearing, Sr., Bruce A. Vicknair, Randall R. Price, Robert A. Baten, Greg L. Cedillo, John H. Craig