Patents by Inventor Stewart Middlemiss

Stewart Middlemiss 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).

  • Publication number: 20030196385
    Abstract: An ultra-hard semiconductive polycrystalline diamond (PCD) material formed with semiconductive diamond particles doped with Li, Be or Al and/or insulative diamond particles having semiconductive surfaces, tools incorporating the same, and methods for forming the same, are provided. The ultra-hard PCD material may be formed using a layer of insulative diamond grit feedstock that includes additives therein, then sintering to convert a plurality of the diamond crystals to include a semiconductive surface. In another embodiment, the ultra-hard PCD material is formed by sintering semiconductive diamond grit feedstock consisting of diamond crystals doped with Li, Al or Be. The ultra-hard semiconductive PCD cutting layer exhibits increased cuttability, especially in EDM and EDG cutting operations.
    Type: Application
    Filed: February 25, 2003
    Publication date: October 23, 2003
    Inventor: Stewart Middlemiss
  • Publication number: 20030162648
    Abstract: Ultra hard materials and ceramics reinforced with elongate ultra hard material particles and methods of forming the same are provided. These materials have improved toughness and damage tolerance and can be used on, or to form, tools such as cutting tools and various work pieces and parts.
    Type: Application
    Filed: February 25, 2003
    Publication date: August 28, 2003
    Inventor: Stewart Middlemiss
  • Patent number: 6604588
    Abstract: A gage trimmer and a bit incorporating such a gage trimmer are provided. The gage trimmer has an ultra hard material layer having a circumferential surface including a cylindrical portion and a flat surface for bearing against a circumferential wall of a hole drilled by the bit. The ultra hard material layer is formed over a substrate interface surface. The flat surface does not extend to the interface surface.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: August 12, 2003
    Assignee: Smith International, Inc.
    Inventors: Ronald K. Eyre, Stewart Middlemiss, Lynn L. Belnap
  • Patent number: 6550556
    Abstract: A cutting layer is provided having a radially extending depression formed on the exposed surface of the cutting element's cutting layer. A corresponding depression may be formed on the substrate end surface below the depression formed on the cutting layer. Furthermore, secondary shallower depressions may be formed on the cutting layer. The cutting element is typically mounted in a drag bit such that the cutting layer radially extending depression makes contact with the earth formations.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: April 22, 2003
    Assignee: Smith International, Inc
    Inventors: Stewart Middlemiss, Ronald K. Eyre
  • Publication number: 20030062201
    Abstract: A gage trimmer and a bit incorporating such a gage trimmer are provided. The gage trimmer has an ultra hard material layer having a circumferential surface including a cylindrical portion and a flat surface for bearing against a circumferential wall of the a hole drilled by the bit. The ultra hard material layer is formed over a substrate interface surface. The flat surface does not extend to the interface surface.
    Type: Application
    Filed: September 28, 2001
    Publication date: April 3, 2003
    Inventors: Ronald K. Eyre, Stewart Middlemiss, Lynn L. Belnap
  • Patent number: 6510910
    Abstract: Cutting elements for incorporation in a drill bit are provided having a body having an end face interfacing with an ultra hard material cutting layer. A main depression having a nonplanar surface is formed on the substrate and extending to the peripheral edge of the substrate subjected to the highest impact loads during drilling. This edge is immediately below the edge of the cutting layer which makes direct contact with the earth formations during drilling. The main depression is formed by forming a plurality of secondary depressions or steps. A second main depression is formed by forming a plurality of secondary depressions or steps. The second main depression also extends to the peripheral edge of the substrate. An ultra hard material layer is bonded to the end face of the cutting element body over the main depressions.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: January 28, 2003
    Assignee: Smith International, Inc.
    Inventors: Ronald K. Eyre, Stewart Middlemiss
  • Publication number: 20020194955
    Abstract: Polycrystalline diamond (PCD) carbide composites of this invention have a microstructure comprising a plurality of granules formed from PCD, polycrystalline cubic boron nitride, or mixture thereof, that are distributed within a substantially continuous second matrix region that substantially surrounds the granules and that is formed from a cermet material. In an example embodiment, the granules are polycrystalline diamond and the cermet material is cemented tungsten carbide. PCD carbide composites of this invention display improved properties of fracture toughness and chipping resistance, without substantially compromising wear resistance, when compared to conventional pure PCD materials.
    Type: Application
    Filed: September 5, 2002
    Publication date: December 26, 2002
    Applicant: Smith International, Inc.
    Inventors: Zhigang Fang, Anthony Griffo, Brian A. White, Stewart Middlemiss, Ronald K. Eyre
  • Patent number: 6454027
    Abstract: Polycrystalline diamond (PCD) carbide composites of this invention have a microstructure comprising a plurality of granules formed from PCD, polycrystalline cubic boron nitride, or mixture thereof, that are distributed within a substantially continuous second matrix region that substantially surrounds the granules and that is formed from a cermet material. In an example embodiment, the granules are polycrystalline diamond and the cermet material is cemented tungsten carbide. PCD carbide composites of this invention display improved properties of fracture toughness and chipping resistance, without substantially compromising wear resistance, when compared to conventional pure PCD materials.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: September 24, 2002
    Assignee: Smith International, Inc.
    Inventors: Zhigang Fang, Anthony Griffo, Brian A. White, Stewart Middlemiss, Ron K. Eyre
  • Publication number: 20020108790
    Abstract: Cutting elements for incorporation in a drill bit are provided having a body having an end face interfacing with an ultra hard material cutting layer. A main depression having a nonplanar surface is formed on the substrate and extending to the peripheral edge of the substrate subjected to the highest impact loads during drilling. This edge is immediately below the edge of the cutting layer which makes direct contact with the earth formations during drilling. The main depression is formed by forming a plurality of secondary depressions or steps. A second main depression is formed by forming a plurality of secondary depressions or steps. The second main depression also extends to the peripheral edge of the substrate. An ultra hard material layer is bonded to the end face of the cutting element body over the main depressions.
    Type: Application
    Filed: February 9, 2001
    Publication date: August 15, 2002
    Inventors: Ronald K. Eyre, Stewart Middlemiss
  • Publication number: 20020071729
    Abstract: A cutting layer is provided having a radially extending depression formed on the exposed surface of the cutting element's cutting layer. A corresponding depression may be formed on the substrate end surface below the depression formed on the cutting layer. Furthermore, secondary shallower depressions may be formed on the cutting layer. The cutting element is typically mounted in a drag bit such that the cutting layer radially extending depression makes contact with the earth formations.
    Type: Application
    Filed: December 7, 2000
    Publication date: June 13, 2002
    Inventors: Stewart Middlemiss, Ronald K. Eyre