Patents by Inventor E. Torbjorn Hartzell

E. Torbjorn Hartzell 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).

  • Cemented carbide body with extra tough behavior
    Patent number: 5453241
    Abstract: The present invention relates to cemented carbide bodies preferably for rock drilling and mineral cutting. Due to the fact that the bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase with low Co-content in the surface zone and successively increasing Co-content to a maximum in the outer part of the eta-phase-core they have obtained an increase in toughness and life at practical use.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: September 26, 1995
    Assignee: Sandvik AB
    Inventors: Jan Akerman, Udo K. R. Fischer, E. Torbjorn Hartzell
  • Cemented carbide body with increased wear resistance
    Patent number: 5413869
    Abstract: A cemented carbide button for rock drilling comprises a core and a surface zone surrounding the core whereby both the surface zone and the core contains WC (alpha-phase) and a binder phase based on at least one of Co, Ni, or Fe and the core in addition contains eta-phase. The eta-phase core extends to the very top (working) surface of the button and as a result is obtained longer life and higher drilling rate particularly for rotating crushing drilling, cutting drilling and percussive drilling in soft rocks.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: May 9, 1995
    Assignee: Sandvik AB
    Inventors: E. Torbjorn Hartzell, Udo K. Fischer, Jan Akerman
  • Cemented carbide body used preferably for abrasive rock drilling and mineral cutting
    Patent number: 5401461
    Abstract: The present invention relates to cemented carbide bodies preferably for wear demanding rock drilling and mineral cutting. The bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase where the binder phase content in the outer pan of said zone is lower than the nominal and, in addition, constant or near constant, and the binder phase content in the inner part of the eta-phase free zone closer to the eta-phase core is higher than the nominal. According to the method of the invention, bodies comprising evenly distributed eta-phase are subjected to a partly carburizing treatment with a carbon activity, a.sub.c, close to 1.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: March 28, 1995
    Assignee: Sandvik AB
    Inventors: E. Torbjorn Hartzell, Jan Akerman, Udo K. R. Fischer
  • Cemented carbide body used preferably for abrasive rock drilling and mineral cutting
    Patent number: 5286549
    Abstract: The present invention relates to cemented carbide bodies preferably for wear demanding rock drilling and mineral cutting. The bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase where the binder phase content in the outer part of said zone is lower than the nominal and, in addition, constant or near constant, and the binder phase content in the inner part of the eta-phase free zone closer to the eta-phase core is higher than the nominal. According to the method of the invention, bodies comprising evenly distributed eta-phase are subjected to a partly carburizing treatment with a carbon activity, a.sub.c, close to 1.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: February 15, 1994
    Assignee: Sandvik AB
    Inventors: E. Torbjorn Hartzell, Jan Akerman, Udo K. R. Fischer
  • Cemented carbide body with extra tough behavior
    Patent number: 5279901
    Abstract: The present invention relates to cemented carbide bodies preferably for rock drilling and mineral cutting. Due to the fact that the bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase with low Co-content in the surface zone and successively increasing Co-content to a maximum in the outer part of the eta-phase-core they have obtained an increase in toughness and life at practical use.
    Type: Grant
    Filed: February 5, 1992
    Date of Patent: January 18, 1994
    Assignee: Sandvik AB
    Inventors: Jan Akerman, Udo K. R. Fischer, E. Torbjorn Hartzell