Patents by Inventor Robert N. Mitchell

Robert N. Mitchell 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: 6716941
    Abstract: The present invention is directed to an ethylene-vinyl acetate dispersion and a process for making the dispersion by polymerizing a monomer mixture having vinyl acetate and ethylene in a batch process, in the presence of a stabilizing system of polyvinyl alcohol and without added surfactants, to form an ethylene-vinyl acetate polymer dispersion. The copolymer dispersion has a solids level of greater than 65 percent by weight, and a viscosity of less than 5000 mPa·s when measured at 65 percent solids at 25° C. The dispersion can be dried to form a redispersible powder. Both the dispersion and powder are useful in adhesive and coating formulations.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: April 6, 2004
    Assignee: National Starch and Chemical Investment Holding Corporation
    Inventors: John C. H. Kerr, Alistair J. McLennan, Robert N. Mitchell, Caroline S. Pattenden
  • Publication number: 20030040558
    Abstract: The present invention is directed to an ethylene-vinyl acetate dispersion and a process for making the dispersion by polymerizing a monomer mixture having vinyl acetate and ethylene in a batch process, in the presence of a stabilizing system of polyvinyl alcohol and without added surfactants, to form an ethylene-vinyl acetate polymer dispersion. The copolymer dispersion has a solids level of greater than 65 percent by weight, and a viscosity of less than 5000 mPa.s when measured at 65 percent solids at 25° C. The dispersion can be dried to form a redispersible powder. Both the dispersion and powder are useful in adhesive and coating formulations.
    Type: Application
    Filed: July 27, 2001
    Publication date: February 27, 2003
    Inventors: John C.H. Kerr, Alistair J. McLennan, Robert N. Mitchell, Caroline S. Pattenden
  • Patent number: 6056484
    Abstract: Both a device and method for adjusting the position of a cutting insert relative to the body of a cutting tool such as a milling cutter are provided. The device includes a cantilevered wall integrally connected to the tool body, that forms a portion of the pocket in the tool body that supports a side of the insert, and a wedge mechanism for elastically flexing the cantilevered wall to adjust the position of a cutting edge of the insert relative to the tool body. The wedge mechanism may take the form of a screw threadedly engaged to the tool body that has a conical head engaged against the cantilevered wall such that when the screw is turned, the conical wedge formed by the screw head flexes the cantilevered wall a small distance. The device advantageously allows fine adjustments to be made in the position of the cutting edge of an insert by the simple turning of a single screw.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: May 2, 2000
    Assignee: Kennametal Inc.
    Inventors: Robert N. Mitchell, Glenn W. Sheffler, Ronald L. Dudzinsky
  • Patent number: 5542795
    Abstract: A milling cutter for performing plunge and face cutting operations on a workpiece with cutting inserts having different shapes is provided that comprises a plurality of cutting inserts having side and transverse cutting edges, the transverse cutting edges being of different shapes for different inserts, a cutter body having a plurality of recessed insert seats for securably receiving the inserts, including a top shoulder spaced apart from the transverse cutting edges of the inserts for allowing the insert seat to receive inserts having transverse edges of different shapes, and a support structure for preventing relative movement between the cutting inserts and their respective seats along the side and transverse insert edges.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: August 6, 1996
    Assignee: Kennametal Inc.
    Inventor: Robert N. Mitchell
  • Patent number: 5102268
    Abstract: The present invention relates to a milling cutter having a cutter body and a plurality of replaceable tool cartridges circumferentially spaced about the outer periphery of the cutter body. An adjustment mechanism permits adjustment of the tool cartridges in the direction parallel to the axis of rotation of the cutter body. The adjustment mechanism includes an adjustment screw threaded into a corresponding bore in the cutter body. The head of the adjustment screw projects into an inclined throughbore in the tool cartridge. When the adjustment screw is turned, the head of the screw bears against the inner surface of the throughbore causing the tool cartridge to be axially displaced. A locking screw is tightened to secure the tool cartridge in place after it has been adjusted.
    Type: Grant
    Filed: May 16, 1991
    Date of Patent: April 7, 1992
    Assignee: Kennametal Inc.
    Inventor: Robert N. Mitchell
  • Patent number: 4648761
    Abstract: A method of efficiently removing material from a workpiece of difficult-to-machine materials. The Z axis machining includes the steps of using a center cutting end mill and forming multiple cylindrical holes having tangent diameters and predetermined depths. Said holes, when formed, leave posts that, when viewed in plan, form stars and cusps. Said stars are then removed by reciprocal movement of said end mill along its Z axis and cusps removed by Z axis machining and/or conventional end milling.
    Type: Grant
    Filed: November 14, 1985
    Date of Patent: March 10, 1987
    Assignee: Kennematel, Inc.
    Inventors: Robert N. Mitchell, James L. Hunt
  • Patent number: 4629370
    Abstract: Disclosed is a sprocket cutter in which there is a cutter body having a plurality of pockets along its periphery and a plurality of wedge recesses facing the periphery within each pocket. There is an array of inserts disposed within each of the pockets, each of the inserts having a cutting portion and a plurality of wedges equal in number to the number of inserts and wedge recesses. Each of the wedges is interposed between each of the inserts and each of the wedge recesses so that, as each of the wedges is moved inwardly into its corresponding wedge recess, each of the inserts is securely clamped between its corresponding wedge and the pocket. Each of the inserts is positioned so that the cutting portion of each insert extends beyond the periphery of the cutter body. Each of the inserts cuts a segment of the sprocket contour as the cutter body rotates with adjacent segments of the sprocket contour being cut by inserts located in different pockets. There is also a method of assembling the sprocket cutter.
    Type: Grant
    Filed: April 19, 1984
    Date of Patent: December 16, 1986
    Assignee: Kennametal Inc.
    Inventors: Douglas E. Torgent, Robert N. Mitchell
  • Patent number: 3953143
    Abstract: A clamping device for disposition in a blind hole or slot of a support body for locating and securing members such as hardened metal cutting inserts and the like. The clamping device of the present invention has an expandable plug member loosely receivable in a blind hole or slot and a rotatable member disposed centrally in the plug member such that upon rotation the plug member expands in the blind hole or slot to firmly clamp an insert between a wall of the blind hole and the expandable plug.
    Type: Grant
    Filed: February 20, 1975
    Date of Patent: April 27, 1976
    Assignee: Kennametal Inc.
    Inventors: Ernest J. Friedline, Robert N. Mitchell, Linn R. Andras
  • Patent number: 3940835
    Abstract: A slotting cutter in which a disc is provided with insert pockets on opposite sides thereof with replaceable cutting inserts of hard wear resistant material mounted in the pockets. The inserts are clamped in the pockets by a wedge which forces the inserts against the rearward and bottom walls of the pockets thereby providing extremely firm support for the inserts. When the disc is viewed in the circumferential direction, the inserts are in overlapping relation and thereby cooperate to cut slots in a work member.
    Type: Grant
    Filed: May 19, 1975
    Date of Patent: March 2, 1976
    Assignee: Kennametal Inc.
    Inventors: Ernest J. Friedline, Robert N. Mitchell