Patents by Inventor Charles D. Spragg

Charles D. Spragg 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: 6834696
    Abstract: A runflat tire is provided that may be used in applications currently requiring a large aspect ratio tire. The runflat tire of the invention may be substituted in these applications while providing desirable ride characteristics. The runflat tire includes a sidewall with a radial portion and a cantilever portion. The cantilever portion may be fabricated by extending a sidewall insert in the axially inward direction or by extending the bead filler in the axially outward direction. In other embodiments, the cantilever sidewall portion is formed by a combination of the sidewall insert and the bead filler. The resulting runflat tire has desired durability in the uninflated operating condition while having desired ride characteristics in the inflated condition. The sidewall structure allows the tire to be used in applications presently requiring a tire with a high aspect ratio.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: December 28, 2004
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Martin A. Yurjevich, Charles D. Spragg, Stephen M. Vossberg, James M. Kirby
  • Patent number: 6769294
    Abstract: The invention provides a tire and a method for analyzing the temperature exposure to the tire. The tire and the method allow an investigator to determine the maximum temperature the tire experienced during its operation. This information offers a potential cause for the tire failure by allowing the investigator to determine a maximum temperature experienced by an area of the tire by reviewing a non-reversible, temperature-indicating label positioned at a location in the tire. The information may be used to identify a potential cause of a tire failure after the failure has occurred. The information may also be used to identify a damaged tire before the tire fails.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: August 3, 2004
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Martin A. Yurjevich, James M. Kirby, Charles D. Spragg, Andrew K. Reinhart
  • Publication number: 20040055686
    Abstract: Tire components comprising a microencapsulated reactant and a reaction facilitator are provided. These components have the ability to resist crack propagation and to self-repair cracks that form within the tire component matrix.
    Type: Application
    Filed: July 22, 2003
    Publication date: March 25, 2004
    Inventors: Katharine M. Cowger, Charles D. Spragg
  • Patent number: 6598634
    Abstract: A laminate contains a composite, comprising a high melting point thermoplastic such as polyphenylene or epoxy and high modulus fibers such as carbon or graphite, which is encapsulated with a resin. A primer adheres the encapsulated composite to a rubber material such as a tire tread. Alternatively, an undertread layer adheres the tire tread to the primed encapsulated composite. The laminate can be used as a run flat belt in a tire.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: July 29, 2003
    Assignee: Bridgestone Corporation
    Inventors: Russell W. Koch, Charles D. Spragg, Edward G. Markow, James M. Kirby
  • Publication number: 20030047264
    Abstract: The invention provides a tire and a method for analyzing the temperature exposure to the tire. The tire and the method allow an investigator to determine the maximum temperature the tire experienced during its operation. This information offers a potential cause for the tire failure by allowing the investigator to determine a maximum temperature experienced by an area of the tire by reviewing a non-reversible, temperature-indicating label positioned at a location in the tire. The information may be used to identify a potential cause of a tire failure after the failure has occurred. The information may also be used to identify a damaged tire before the tire fails.
    Type: Application
    Filed: September 7, 2001
    Publication date: March 13, 2003
    Inventors: Martin A. Yurjevich, James M. Kirby, Charles D. Spragg, Andrew K. Reinhart
  • Patent number: 6470937
    Abstract: A run flat pneumatic tire has a thin annular band embedded in the crown portion of the tire. The band is formed of a composite material such as tows of fiberglass and/or graphite material impregnated with a resin. The resin coated tows are wound about a mandrel having at least one concave recess to provide the band with an anticlastic shape with an arcuate cross section and a concave surface facing radially outwardly.
    Type: Grant
    Filed: October 3, 2000
    Date of Patent: October 29, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Charles D. Spragg, Stephen M. Vossberg, James M. Kirby, Edward G. Markow
  • Patent number: 6460586
    Abstract: A run flat pneumatic tire includes a thin annular band embedded in the crown portion of the tire wherein the band is formed with three distinct regions. Radially spaced inner and outer regions are formed of high modulus materials and a central region is formed of a material more elastic than the other two regions providing a band having high interlaminar shear strength. Reinforcing fibers are placed in various orientations in certain of the regions to enable various materials to achieve the required band stiffness for load carrying capability and the interlaminar shear strength at the central axis of the band.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: October 8, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6439288
    Abstract: A run flat pneumatic tire has a thin annular band embedded in the crown portion of the tire. The band is formed of a multilayer composite formed of wound layers of a material such as fiberglass and/or graphite impregnated with a resin. The band has a radial cross-sectional thickness with a neutral axis extending through the center in an axial direction. The radial thickness of the band decreases from an axial midpoint toward outer ends of the band to provide greater thickness in the center of the band to reduce interlaminar shear fatigue.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: August 27, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Charles D. Spragg, Stephen M. Vossberg, James M. Kirby, Edward G. Markow
  • Patent number: 6436215
    Abstract: A band element for mounting in the crown portion of a pneumatic tire to provide run flat ability to the tire in the event of loss of air pressure and to provide increased puncture resistance. The band is formed of flat strips of tape having fibers embedded in a resin matrix which are twisted and then pultrated to provide a rectangular cross sectional configuration. The twisted tape is wrapped about a mandrel and forms either the only layer, or the intermediate layer of a composite band in combination with inner and outer layers of flat tape or wound filament fibers, whereby the fibers in the tape extend across the central axis of the band to reduce interlaminar sheer. In another embodiment, a plurality of dimples or depressions are formed in the individual tape layers to extend a plurality of the fibers across the layer boundaries to reduce interlaminar sheer.
    Type: Grant
    Filed: February 24, 2000
    Date of Patent: August 20, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6420005
    Abstract: A run flat pneumatic tire has a thin annular band embedded in a crown portion of the tire. The band preferably is a composite member formed of a plurality of layers elongated strip material providing the band with inner and outer annular axially extending surfaces terminating in a pair of outer end portions. Either one or both of the outer end portions are tapered toward the other end portion and toward a pair of end edges to reduce interlaminar shear. The end edges can be straight or rounded surfaces and the tapered outer end portions may be coated with fiber filled epoxy coating.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: July 16, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6405773
    Abstract: A pneumatic tire is reinforced by a thin annular composite band embedded in the crown portion of the tire to enable the tire to resist compressive forces in the tire when in an uninflated condition. The band is formed of a plurality of wound layers of first and second resin coated fiber tows wherein the first tow is formed of fibers twisted at a greater angle than the fibers in the second tow. Layers of the first tow are located adjacent the neutral axis of the band to provide interlaminar shear strength with the tow layers located adjacent the inner and outer surfaces of the band being formed predominately of the second tow to provide a high level circumferential stiffness. The intermediate tow layers are formed of both type of tows to provide a transition zone between the central interlaminar shear strength and the outer circumferential stiffness.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: June 18, 2002
    Assignee: Bridgestone/Firestone North American Tire, LLC
    Inventors: Stephen M. Vossberg, Charles D. Spragg, Edward G. Markow
  • Patent number: 6363986
    Abstract: A method for building a run flat pneumatic tire by precoating a thin high strength annular band of material with a layer of rubber to form a rubber/band composite. The rubber coated band composite is at least partially cured and then assembled between a body ply carcass and a tread package in a usual second stage tire building machine. The band can be encased completely with the rubber or the rubber can be applied only to the outside surface, the inside surface or the end edges of the band or any combination thereof.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: April 2, 2002
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6321808
    Abstract: A run flat pneumatic tire includes a thin annular monolithic band embedded in the crown portion of the tire wherein the band has a helical cut extending between opposite band edges. The cut has an arcuate length between 45° and 360° and provides a circumferentially expandable band which enhances molding of the tire by enabling the band to expand during molding to minimize porosity and reduce entrapment of air between the band and tread rubber. Alternately, a pair of helically cut bands are joined by an intervening band of rubber and a reinforcing layer of reinforcing cords in a rubber skim may extend about the outer surface of the expandable band or bands.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: November 27, 2001
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6260593
    Abstract: A pneumatic race tire has an elastomeric casing with a tread in the crown portion thereof, a pair of bead areas and a body ply carcass extending continuously between the bead areas and through the sidewalls and crown portion. A continuous thin annular band formed of a high strength, lightweight material such as metal, fiberglass, a composite material or the like is located radially inwardly of the tread and between the tread and body ply carcass to enhance tire performance by reducing the thickness of the tread area.
    Type: Grant
    Filed: August 3, 1999
    Date of Patent: July 17, 2001
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, Gregory D. Chaplin, Dale R. Harrigle, Jr., James M. Kirby
  • Patent number: 6148885
    Abstract: A band element for mounting in the crown portion of a pneumatic tire to provide run flat ability to the tire in the event of loss of air pressure and to provide increased puncture resistance is formed of flat strips of tape having fibers embedded in a resin matrix which in one embodiment are twisted and then pultruded to provide a rectangular cross sectional configuration. The twisted tape is wrapped about a mandrel and forms either the only layer, or the intermediate layer of a composite band in combination with inner and outer layers of flat tape or wound filament fibers, whereby the fibers in the tape extend across the central axis of the band to reduce interlaminar sheer. In another embodiment, a plurality of dimples or depressions are formed in the individual tape layers to extend a plurality of the fibers across the layer boundaries to reduce interlaminar sheer.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: November 21, 2000
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6117258
    Abstract: A method for building a run flat pneumatic tire by precoating a thin high strength annular band of material with a layer of rubber to form a rubber/band composite. The rubber coated band composite is at least partially cured and then assembled between a body ply carcass and a tread package in a usual second stage tire building machine. The band can be encased completely with the rubber or the rubber can be applied only to the outside surface, the inside surface or the end edges of the band or any combination thereof.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: September 12, 2000
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 6112791
    Abstract: A run flat pneumatic tire has a thin annular band embedded in a crown portion of the tire. The band preferably is a composite member formed of a plurality of layers elongated strip material providing the band with inner and outer annular axially extending surfaces terminating in a pair of outer end portions. Either one or both of the outer end portions are tapered toward the other end portion and toward a pair of end edges to reduce interlaminar shear. The end edges can be straight or rounded surfaces and the tapered outer end portions may be coated with fiber filled epoxy coating.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: September 5, 2000
    Assignee: Bridgestone/Firestone Research, Inc.
    Inventors: Charles D. Spragg, James M. Kirby, Edward G. Markow
  • Patent number: 5879484
    Abstract: A run flat pneumatic tire is reinforced by a thin annular composite band imbedded in the crown portion of the tire in combination with a plurality of radial cords or plies in its sidewalls which have freedom in shear with respect to one another. The band is formed by a plurality of layers of material strips wherein each strip is wound in a helical pattern, with adjacent strips being wound at reverse angles to each other. Each layer is formed under sufficient pressure and at an elevated temperature whereby the band is prestressed in tension which decreases the maximum stress at the footprint area of the tire. The invention furthermore incorporates the method of imparting the prestress on the annular band during its manufacture.
    Type: Grant
    Filed: January 13, 1997
    Date of Patent: March 9, 1999
    Assignee: Bridgestone/Firestone, Inc.
    Inventors: Charles D. Spragg, Edward G. Markow, Thomas W. Bell
  • Patent number: 5769980
    Abstract: A pneumatic passenger tire has an aspect ratio of greater than 50%, having bead portions with a height of not less than 30% of the tire section height, but no greater than the height of the maximum section width of the tire, and a pair of crescent-shaped sidewall inserts on either side of the belt package, disposed axially inward of the carcass structure, wherein the sidewall insert has a first inner end located at a position between 15% and 45% of height H of the bead portions, and a second outer end which extends to an axial position of not less than 40% of a half width of the outermost belt, as measured from the lateral edge of the belt toward an equatorial plane EP of the tire. The tire construction has sidewall insert is comprised of a sulfur-vulcanizable rubber compound having high compressive flex fatigue, high modulus and low hysterisis subsequent to vulcanization.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: June 23, 1998
    Assignee: Bridgestone/Firestone, Inc.
    Inventors: Charles D. Spragg, Thomas W. Bell, William L. Hergenrother, James M. Kirby
  • Patent number: 5267847
    Abstract: A compact and precision extrusion system for extruding strips of rubber compounds with profiles of accurate dimensions. Strips of rubber compound are uniformly heated and mixed in an extruder and then passed through a low pressure drop strainer to remove foreign matter. The strained compound then is fed directly into a gear pump which delivers precise volumes of the rubber compound immediately into the spread chamber of an extrusion head after which it passes through a die to form a precise strip of the rubber compound. The strainer and extrusion head are movably mounted with respect to the gear pump for axial separation from the gear pump for easy removal of the rubber compound from the various components of the system to facilitate compound changes. A control system regulates the speed of the extruder to provide a near constant pressure at the entrance port of the gear pump to precisely regulate the rate of extrusion of the compound from the extrusion head.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: December 7, 1993
    Assignee: Bridgestone Corporation
    Inventors: Georg G. A. Bohm, Arthur W. Greenstreet, Gregory D. Chaplin, Charles D. Spragg