Patents by Inventor Stefan Georgiev Semerdjiev

Stefan Georgiev Semerdjiev 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 of injection molding a thermoplastic article having a cellular core and integral skin involving use of reclaimed material
    Patent number: 3960996
    Abstract: A method of and apparatus for the molding of foamed thermoplastic bodies with integral skins wherein, for each mold operation after the first, a portion of previously foamed material produced by expansion in the mold cavity, is temporarily accumulated behind a body of unfoamed thermoplastic and the foamed and unfoamed material are then forced into the mold cavity and permitted to expand therein.
    Type: Grant
    Filed: September 21, 1973
    Date of Patent: June 1, 1976
    Assignee: Institut po Metaloznanie i Technologia na Metalite
    Inventors: Anguel Tonchev Balevski, Ivan Dimov Nikolov, Asparuh Mihailov Antonov, Stefan Georgiev Semerdjiev
  • Device for the production of articles with a compact smooth skin and a cellular core from polymer materials
    Patent number: 3949905
    Abstract: An apparatus for the production of articles with a compact smooth skin and a cellular core from polymer materials, which contain blowing agents, by injection molding or extrusion wherein the apparatus contains an electric heating element within a channel through which the polymeric material is passed.
    Type: Grant
    Filed: June 5, 1974
    Date of Patent: April 13, 1976
    Assignee: Institute po Metaloznanie i Technologia na Metalite
    Inventors: Ivan Dimov Nikolov, Stefan Georgiev Semerdjiev, Dragan Iliev Nenov, Nikolay Tihomirov Popov