Patents by Inventor Salvador Espana

Salvador Espana 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).

  • Friction bearing rock bit and segment
    Patent number: 4249621
    Abstract: A rock bit segment has a cutter rotatably mounted on a journal. Loads radially of the axis of the journal are largely taken by a friction bearing pad of hard material. Ball bearings track in circular races on the journal and cutter and retain the cutter on the journal. A seal at the junction of the journal and the balance of the segment keep lubricant from escaping from the interface between the cutter and the journal and formation material from entering this interface. To provide hardened wear surfaces for the seal on the journal and segment in the ball race on the journal, on radial surfaces of the journal adjacent the pad, and at the nose of the journal, the entire rock bit segment is subjected to a carbon enrichment of the surface after the segment has been machined. Thereafter, the segment is quenched to effect a hardened case, and then the segment is tempered. Carbon in the case varies from 0.5% to 0.9% at the surface-to-base metal concentrations at depth, and the case is 0.010 to 0.015 inches thick.
    Type: Grant
    Filed: March 22, 1979
    Date of Patent: February 10, 1981
    Assignee: Smith International, Inc.
    Inventor: Salvador Espana
  • Friction bearing rock bit and segment, and method for making them
    Patent number: 4204437
    Abstract: A rock bit segment has a cutter rotatably mounted on a journal. Loads radially of the axis of the journal are largely taken by a friction bearing pad of hard material. Ball bearings track in circular races on the journal and cutter and retain the cutter on the journal. A seal at the junction of the journal and the balance of the segment keep lubricant from escaping from the interface between the cutter and the journal and formation material from entering this interface. To provide hardened wear surfaces for the seal on the journal and segment in the ball race on the journal, on radial surfaces of the journal adjacent the pad, and at the nose of the journal, the entire rock bit segment is subjected to a carbon enrichment of the surface after the segment has been machined. Thereafter, the segment is quenched to effect a hardened case, and then the segment is tempered. Carbon in the case varies from 0.5% to 0.9% at the surface to base metal concentrations at depth, and the case is 0.010 to 0.015 inches thick.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: May 27, 1980
    Assignee: Smith International, Inc.
    Inventor: Salvador Espana