Patents by Inventor Leif Hermansson

Leif Hermansson 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).

  • Patent number: 5306673
    Abstract: The present invention relates to a method to manufacture a composite ceramic material having a high strength combined with bioactive properties, when the material is used as a dental or orthopedic implant, which includes preparing a powder mixture, mainly comprising partly a first powder, which in its used chemical state will constitute a bioinert matrix in the finished material , and partly a second powder, mainly comprising a calcium phosphate-based material. The invention is characterized in that said first powder comprises at least one of the oxides belonging to the group consisting of titanium dioxide (TiO.sub.2), zirconium oxide (ZrO.sub.2) and aluminum oxide (Al.sub.2 O.sub.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: April 26, 1994
    Assignee: Stiftelsen Centrum for Dentalteknik och Biomaterial i Huddinge
    Inventors: Leif Hermansson, Sevald Forberg, Li Jiangou
  • Patent number: 4778650
    Abstract: In the manufacture of an object of a powdered material by isostatic pressing of a body (10) preformed from the powdered material with a gaseous pressure medium, the preformed body is provided with a casing (13) of glass which is made gas-impenetrable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body an intermediate layer (12) which counteracts the penetration of molten glass from the casing into the preformed body. The intermediate layer comprises a layer of one or more intermediate phases in the system Al.sub.2 O.sub.3 --SiO.sub.2, for example mullite 3Al.sub.2 O.sub.3.2SiO.sub.2, or a layer containing one or more such intermediate phases as main constituent. In a preferred embodiment a layer of boron nitride is arranged inside the intermediate layer. In a preferred embodiment, the powdered object consists of aluminium oxide or an aluminium oxide-based ceramic.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: October 18, 1988
    Assignee: ASEA Cerama AB
    Inventors: Leif Hermansson, Anna-Karin Tjernlund
  • Patent number: 4717535
    Abstract: When manufacturing an object of powdered material by isostatic pressing of a body (10), preformed from the powdered material, with a gaseous pressure medium, the preformed body is provided with a casing (19) of glass which is made gas-impermeable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body a barrier layer (11) which counteracts the penetration of melted glass from the enclosure in the preformed body. The barrier layer is built up of at least two layers, of which one layer (12) at least substantially consists of powdered boron nitride and one layer (13) of a mixture of powdered boron nitride and a powdered material with the ability, upon contact with glass from the casing in melted form, to make a layer containing boron nitride tighter.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: January 5, 1988
    Assignee: ASEA Cerama AB
    Inventors: Jan Adlerborn, Leif Hermansson, Hans Larker, Bertil Mattsson, Jan Nilsson