Patents by Inventor Stephen P. Stiffler

Stephen P. Stiffler 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: 4941711
    Abstract: A cemented carbide tip for a cutter bit is rotationally symmetric about its longitudinal axis and has a socket in its rear end for brazing to a steel protrusion on a steel tool shank. The tip socket and an outer rearmost facing surface on the tip rear end have respective pluralities of first and second bumps thereon for spacing, centering and aligning the tip on the bit body to facilitate formation of a braze joint of a desired given cross-sectional thickness profile between the tip and bit body.
    Type: Grant
    Filed: January 27, 1989
    Date of Patent: July 17, 1990
    Assignee: Kennametal Inc.
    Inventor: Stephen P. Stiffler
  • Patent number: 4940288
    Abstract: A cutter bit for use in construction and/or excavation applications is provided having a hard wear resistant tip joined to a steel shank. The wear resistant tip is rotational symmetric about its longitudinal axis and has a rear end having a socket therein in which is bonded a steel protrusion on the forward end of the steel shank. The tip socket and an outer rearmost facing surface on the tip rear end have respective pluralities of first and second bumps formed thereon and protruding therefrom for spacing, centering and aligning the tip on the bit body to facilitate formation of a braze joint of a desired given cross-sectional thickness profile between the tip and bit body.
    Type: Grant
    Filed: January 27, 1989
    Date of Patent: July 10, 1990
    Assignee: Kennametal Inc.
    Inventors: Stephen P. Stiffler, Wayne H. Beach
  • Patent number: 4917196
    Abstract: An excavating tooth for use in connection with an earth drilling auger includes a main body portion terminating in a working end and a shank extending upwardly from the main body portion. A plurality of tungsten carbide inserts are embedded in the working end of the tooth and project outwardly therefrom. During drilling operations, the carbide inserts engage the earth and chisel away rock and other material which is subsequently conveyed to the surface by the fight structure of the auger. The inserts are inclined forwardly with respect to the plane of the shank to enable the inserts to withstand greater loads than before. In the preferred embodiment, the insert has a generally cylindrical proximal end embedded in the working end of the auger tooth and a distal end including forward and rearward inclined surfaces terminating in a transverse cutting edge.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: April 17, 1990
    Assignee: Kennametal Inc.
    Inventors: Stephen P. Stiffler, Wayne H. Beach, Don C. Rowlett, Steven D. Shirk
  • Patent number: 4911504
    Abstract: A cemented carbide tip is provided with a socket for mounting onto the steel shank of a cutter bit. The socket has an annular convex surface therein extending from the earth engaging portion of the tip radially inwardly and forwardly. This convex surface is brazed to the forward end of a steel shank to form a cutter bit.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: March 27, 1990
    Assignee: Kennametal Inc.
    Inventors: Stephen P. Stiffler, Wayne H. Beach, John J. Prizzi
  • Patent number: 4911503
    Abstract: A cutter bit for use in construction and/or excavation applications is provided having a hard wear resistant tip joined to a steel shank. The wear resistant tip is rotational symmetric about its longitudinal axis and has a rear end having a socket therein in which is bonded a steel protrusion on the forward end of the steel shank.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: March 27, 1990
    Assignee: Kennametal Inc.
    Inventors: Stephen P. Stiffler, Wayne H. Beach
  • Patent number: 4817743
    Abstract: Formation of a double sandwich braze joint between the steel body of a bit and a carbide insert tip disposed in a groove formed across the body is facilitated by a butterfly-type shim having a semiopened bottom placed within the groove between surfaces on the bit body defining the groove and adjacent surfaces on the insert tip. The shim has a pair of upstanding spaced side walls and a pair of spaced bottom webs extending between and interconnecting the side walls so as to dispose them between adjacent side surfaces of the bit body groove and insert tip, with lower edges of the shim side walls disposed generally above the bottom webs. The bottom webs rest on the bottom surface of the bit body groove and, in turn, elevate the shim side walls so that their lower edges are spaced above the groove bottom surface.
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: April 4, 1989
    Assignee: Kennametal Inc.
    Inventors: Mark S. Greenfield, Stephen P. Stiffler, Raymond D. Evans