Patents Assigned to Vallourec, S. A.
  • Patent number: 4660398
    Abstract: The invention relates to a process for controlling a rolling mill having oblique rolls which is used for rolling metal rods or tubes, and to the rolling mill for carrying out the process. The rolling mill according to the invention comprises at least three rolls distributed round the rolling axis, each of the rolls having a profile generated by revolution of decreasing cross-section, the roll axes not intersecting the rolling axis, and each of the rolls exerting on the product a pressure which permits helicoidal rolling to be carried out. The process involves controlling the forward feed while keeping the angle of inclination of each of the axes of revolution of the rolls constant relative to a secant straight line, the so-called control axis, which is a straight line perpendicular to the rolling axis and intersecting said rolling axis and which traverses the zone of contact between the roll and the product to be rolled.
    Type: Grant
    Filed: March 26, 1985
    Date of Patent: April 28, 1987
    Assignee: Vallourec S.A.
    Inventors: Jean-Marc Jour, Pierre Peytavin
  • Patent number: 4550937
    Abstract: Threaded pipe joint in which tip of the male member engages shoulder within the female member and any excess in the outer diameter of the male member over the corresponding inner diameter of the female member is so small that the hoop stress in the female member does not exceed the axial stress therein.
    Type: Grant
    Filed: December 10, 1979
    Date of Patent: November 5, 1985
    Assignee: Vallourec S.A.
    Inventor: Jean Duret
  • Patent number: 4541262
    Abstract: The process and the device which are the object of the invention relate to the cold rolling of tubes by means of a Pilger mill. The tube blank is made to advance near each of the upstream and downstream dead centers reached by the roll stand during its forward and return cyclical movement and backward movement of the rear part of the blank is made possible during a return pass of the roll stand. This process makes possible a doubling of production without changing the operating rate of the roll stand.
    Type: Grant
    Filed: July 20, 1983
    Date of Patent: September 17, 1985
    Assignee: Vallourec S.A.
    Inventor: Pierre Peytavin
  • Patent number: 4494777
    Abstract: A threaded pipe joint including male and female sections, each with corresponding closed angle threading. Cooperating abutments are on the respective male and female sections. The closed angle threading diminishes in height in the region adjacent the abutments, which limit axial movement of the sections with respect to each other and thereby prevent movement which would permit the closed angle threads to separate.
    Type: Grant
    Filed: May 23, 1984
    Date of Patent: January 22, 1985
    Assignee: Vallourec, S.A.
    Inventor: Jean Duret
  • Patent number: 4398756
    Abstract: Separable joint for oil well pipe in which both the male and female members have a cylindrical threaded section adjacent a frusto-conical thread section, and the female member has an internal shoulder against which the end of the male member seals.
    Type: Grant
    Filed: November 13, 1981
    Date of Patent: August 16, 1983
    Assignee: Vallourec, S. A.
    Inventors: Jean Duret, Charles Soulier, Georges Trouillet