Patents by Inventor Berwyn C. Thomas

Berwyn C. Thomas 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).

  • Apparatus for injection molding against a preformed web
    Patent number: 4269579
    Abstract: Apparatus for injection-moulding articles of plastics material onto a preformed web inserted into the mould, the web is held under substantially constant tension during the closing of the mould, between a pair of clamps, the proximal clamp being fixed relative to the mould and the distal clamp free but bearing a load to furnish the desired tension in the web. The load may be imposed by a weight attached to the distal clamp, conveniently by means of an electromagnet.
    Type: Grant
    Filed: January 22, 1980
    Date of Patent: May 26, 1981
    Assignee: Imperial Chemical Industries Limited
    Inventor: Berwyn C. Thomas
  • Method of injection-moulding onto a preformed web
    Patent number: 4216184
    Abstract: In a method of injection-moulding articles of plastics material onto a preformed web inserted into the mould, the web is held under substantially constant tension during the closing of the mould, between a pair of clamps, the proximal clamp being fixed relative to the mould and the distal clamp free but bearing a load to furnish the desired tension in the web. The load may be imposed by a weight attached to the distal clamp, conveniently by means of an electromagnet.
    Type: Grant
    Filed: September 6, 1977
    Date of Patent: August 5, 1980
    Assignee: Imperial Chemical Industries Limited
    Inventor: Berwyn C. Thomas