Patents by Inventor Ernst Zimmert

Ernst Zimmert 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 and apparatus to reduce the outer diameter and wall thickness of a hollow tube blank by rolling
    Patent number: 5125251
    Abstract: In a process for reducing the outer diameter and wall thickness of an essentially cylindrical hollow tube blank by rolling, the front end of the tube blank is introduced into a rolling mill. To prevent piping defects during rolling and to obviate other disadvantages of conventional processes, the diameter and/or the wall thickness of the trailing end portion of the tube blank is reduced before the trailing end portion is introduced into the reduction zone of the rolling mill.
    Type: Grant
    Filed: January 7, 1991
    Date of Patent: June 30, 1992
    Assignee: Mannesmann AG
    Inventors: Gustav-Adolf Pettersson, Ernst Zimmert, Bengt Jagaeus, Aake Sandberg