Patents by Inventor James Elphick

James Elphick 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).

  • Well treatment valve
    Patent number: 4450914
    Abstract: A well treatment valve includes spring means within a spring chamber acting against an actuating rod movable against a valve body to open and close the valve. The spring means is sealed against pressure in an inlet to the valve while a passage communicates between the valve inlet and the spring chamber. The spring means is a gas spring.
    Type: Grant
    Filed: January 25, 1982
    Date of Patent: May 29, 1984
    Assignee: Dresser Industries, Inc.
    Inventor: James Elphick