Patents by Inventor Per Billgren

Per Billgren 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: 6564689
    Abstract: Blank for a gun barrel, consisting of a steel bar, which bar, in one or more hot working steps, has been repeatedly wrung about its own longitudinal axis.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: May 20, 2003
    Assignee: Damasteel Aktiebolag
    Inventor: Per Billgren
  • Patent number: 5815790
    Abstract: The invention relates to a method for the manufacturing of a composite metal product. More particularly, the invention relates to a method for the manufacturing of a composite product consisting of at least two stainless steel materials having different chemical compositions, particularly a composite stainless product on which decorative patterns can or has been produced by etching.It is significant feature of the invention that at least two stainless steel materials having different chemical compositions are bonded together through hot isostatic compaction at a pressure exceeding 600 bar and a temperature exceeding 1000.degree. C., at least one of said materials consisting of powder, for the achievement of a consolidated body.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: September 29, 1998
    Assignee: Soderfors Powder Aktiebolag
    Inventors: Per Billgren, Kaj Embretsen
  • Patent number: 5540882
    Abstract: The invention concerns a method relating to powder metallurgical manufacturing of a body having a through hole, for example a hollowed tool blank or thick-walled tube. The characteristic feature of the method is that in an outer capsule there is provided a tube (6) having substantially the same length as the capsule, so that the tube extends substantially through the entire length of the capsule, that in the tube there is provided a core (5) which also extends through the capsule and the entire length of the tube, that the space between the tube (6) and the inner side of the capsule (1) is filled with a metal powder (9) which shall form the desired body, that the space (10) in the tube (6) between the core (5) and the inner side of the tube is filled with a non-metallic powder (11), that the capsule is closed hermetically, and that the closed capsule and its content is subjected to hot isostatic compaction at a temperature exceeding 1000 C., so that the metal powder is compacted to complete density.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: July 30, 1996
    Assignee: Erasteel Kloster Aktiebolag
    Inventor: Per Billgren
  • Patent number: 4748088
    Abstract: The invention relates to a blank for a tool die, made of compound steel with a core of high speed steel and a surrounding ring of a different steel, said ring bringing about a prestress in the core. According to the invention, the prestress is due to the fact that the core consists of a high speed steel powder which has been compacted to full density, that the ring consists of a steel alloy, the residual austenite transformation to martensite and consequent volume increase of which is zero or considerably less than the residual austenite transformation to martensite of the high speed steel after the same heat treatment, and that the blank has been hardened and tempered to create in the core a compression stress as a result of the obstruction by the surrounding ring of the volume increase of the core.The invention relates also to a method for manufacturing such blanks. A high speed steel powder is filled into a thick-walled pipe, said pipe consisting of a steel different from high speed steel.
    Type: Grant
    Filed: June 19, 1985
    Date of Patent: May 31, 1988
    Assignee: Kloster Speedsteel Aktiebolag
    Inventor: Per Billgren
  • Patent number: 4265700
    Abstract: PCT No. PCT/SE78/00029 Sec. 371 Date May 9, 1979 Sec. 102(e) Date May 9, 1979 PCT Filed Aug. 10, 1978 PCT Pub. No. WO79/00137 PCT Pub. Date Mar. 22, 1979This specification describes a method of separating a fine-grained close-packed solid material from a liquid with which the fine-grained material is saturated. The material may by way of example consist of grindings; metal-containing pickling bath deposits; or metal oxides from metallurgical venturi-filter. The moist mixture (1) is packed in a container (2) which thereafter is closed and heated from underneath. The liquid is evaporated starting from the lower portions in the container and forces liquid from the upper portions towards the surface of the paste-like mixture, wherefrom collected liquid (9) can be removed. Common oil drums can be used as containers.
    Type: Grant
    Filed: May 9, 1979
    Date of Patent: May 5, 1981
    Assignee: Uddeholms Aktiebolag AB
    Inventors: Per A. Billgren, Stig A. Karlsson