Patents by Inventor David J. Derwin

David J. Derwin 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: 8999898
    Abstract: A method for controlling the loss of drilling fluid from an oil well borehole into formations penetrated by a drill bit is disclosed by which resilient graphitic carbon particles having a resiliency greater than about 130% rebound after compression to 10,000 psi; a degree of graphitization greater than 85%, as measured by d002 using XRD; an average pore size larger than 0.035 micron; and an aspect ratio smaller than 0.63 are added to the drilling fluid.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: April 7, 2015
    Assignee: Superior Graphite Co.
    Inventors: Changjun Zhou, David J. Derwin, Frank A. Wawrzos
  • Publication number: 20140274816
    Abstract: A method for controlling the loss of drilling fluid from an oil well borehole into formations penetrated by a drill bit is disclosed by which resilient graphitic carbon particles having a resiliency greater than about 130% rebound after compression to 10,000 psi; a degree of graphitization greater than 85%, as measured by d002 using XRD; an average pore size larger than 0.035 micron; and an aspect ratio smaller than 0.63 are added to the drilling fluid.
    Type: Application
    Filed: March 15, 2013
    Publication date: September 18, 2014
    Applicant: Superior Graphite Co.
    Inventors: Changjun Zhou, David J. Derwin, Frank A. Wawrzos
  • Patent number: 8617309
    Abstract: A method for improving the thermal characteristics of cement compositions is provided in which fine resilient graphitic carbon particles (“RGC”) are substituted for a portion of the fine aggregate (typically sand) in the cement formulation. For the purposes of the present disclosure, “fine” is intended to describe particulates having a mesh size of less than about 8 mesh, or a particle size of less than about 2.38 mm, or, more preferably when referring to RGC, a mesh size of less than about 16 mesh and a particle size of less than about 1.19 mm. “Resilient” is intended to describe graphitic carbon particles that exhibit a rebound of at least about 20% after compression to 10,000 psi.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: December 31, 2013
    Assignee: Superior Graphite Co.
    Inventors: Peter Roy Carney, Craig Allen Baer, David J. Derwin, Changjun Zhou, Frank A. Wawrzos, Marcin Tlustochowicz
  • Patent number: 6971819
    Abstract: An electrically conductive paving system that has enhanced conductivity of the conductive graphite/asphalt layer. This is achieved by incorporating into the paving mixture a blend of two naturally occurring crystalline flake graphites, one being coarse (generally larger than 40 mesh/425 microns) and the other being fine (generally smaller than 100-200 mesh/150-75 microns). The ratio of course flake graphite to fine flake graphite may be from 1.5:1 and 1:1.5, but is preferably approximately 1:1.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: December 6, 2005
    Assignee: Superior Graphite Co.
    Inventors: Peter L. Zaleski, David J. Derwin, Walter H. Flood, Jr.
  • Publication number: 20040062606
    Abstract: An electrically conductive paving system that has enhanced conductivity of the conductive graphite/asphalt layer. This is achieved by incorporating into the paving mixture a blend of two naturally occurring crystalline flake graphites, one being coarse (generally larger than 40 mesh/425 microns) and the other being fine (generally smaller than 100-200 mesh/150-75 microns). The ratio of course flake graphite to fine flake graphite may be from 1.5:1 and 1:1.5, but is preferably approximately 1:1.
    Type: Application
    Filed: November 3, 2003
    Publication date: April 1, 2004
    Inventors: Peter L. Zaleski, David J. Derwin, Walter H. Flood, Jr.
  • Publication number: 20040048162
    Abstract: An engineered carbonaceous material (ECM) comprising a mixture of synthetic graphite and one or more other graphite, such as natural flake graphite, natural vein graphite, and/or amorphous graphite. The objects are also achieved by an ECM comprising a mixture of expanded graphite and one or more other graphite materials, such as natural flake graphite, natural vein graphite, amorphous graphite and/or synthetic graphite. The ECM is preferably mixed with 0.01 to 20.0 wt. % MnO2 to create a battery active material. The mixtures may be made by either co-blending or co-grinding the graphites together. An electrochemical cell incorporating the material is also contemplated.
    Type: Application
    Filed: September 9, 2003
    Publication date: March 11, 2004
    Inventors: Igor V. Barsukov, Peter L. Zaleski, David J. Derwin, Richard J. Girkant, Maritza Gallego
  • Patent number: 6660434
    Abstract: An engineered carbonaceous material (ECM) comprising a mixture of synthetic graphite and one or more other graphite, such as natural flake graphite, natural vein graphite, and/or amorphous graphite. The objects are also achieved by an ECM comprising a mixture of expanded graphite and one or more other graphite materials, such as natural flake graphite, natural vein graphite, amorphous graphite and/or synthetic graphite. The ECM is preferably mixed with 0.01 to 20.0 wt. % MnO2 to create a battery active material. The mixtures may be made by either co-blending or co-grinding the graphites together. An electrochemical cell incorporating the material is also contemplated.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: December 9, 2003
    Assignee: Superior Graphite Co.
    Inventors: Igor V. Barsukov, Peter L. Zaleski, David J. Derwin, Richard J. Girkant, Maritza Gallego
  • Publication number: 20010041293
    Abstract: An engineered carbonaceous material (ECM) comprising a mixture of synthetic graphite and one or more other graphite, such as natural flake graphite, natural vein graphite, and/or amorphous graphite. The objects are also achieved by an ECM comprising a mixture of expanded graphite and one or more other graphite materials, such as natural flake graphite, natural vein graphite, amorphous graphite and/or synthetic graphite. The ECM is preferably mixed with 0.01 to 20.0 wt. % Mn02 to create a battery active material. The mixtures may be made by either co-blending or co-grinding the graphites together. An electrochemical cell incorporating the material is also contemplated.
    Type: Application
    Filed: March 6, 2001
    Publication date: November 15, 2001
    Inventors: Igor V. Barsukov, Peter L. Zaleski, David J. Derwin, Richard J. Girkant, Maritza Gallego
  • Patent number: 6287694
    Abstract: A method for making expanded graphite from lamellar flake graphite comprising first providing lamellar flake graphite particles having at least a minimal purity, then intercalating the lamellar flake graphite particles with an expandable graphite intercalation compound, followed by expanding the graphite intercalation compound to exfoliate the flake graphite particles, and finally air milling the exfoliated flake graphite particles to further delaminate them.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: September 11, 2001
    Assignee: Superior Graphite Co.
    Inventors: Peter L. Zaleski, David J. Derwin, Richard J. Girkant
  • Patent number: 5826669
    Abstract: A method of preventing or controlling the loss of well drilling fluid into the pores and fractures of subterranean rock formations by the addition of resilient graphitic carbon particles to the drilling fluid in sufficient amounts to plug the pores and fractures. The graphitic carbon material reduces loss of circulation, lowers torque and drag, prevents casing wear while drilling, and provides a new method for the controlled release of graphite at extreme pressure. The material is non-toxic and imparts the well-known lubricating properties of graphite without contributing to surface sheen development under US EPA offshore cuttings discharge rules.
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: October 27, 1998
    Assignee: Superior Graphite Co.
    Inventors: Peter L. Zaleski, David J. Derwin, Donald J. Weintritt, George W. Russell
  • Patent number: 5707171
    Abstract: An electrically conductive paving mixture for use in a pavement system which prevents the accumulation of frozen precipitation on surfaces, for example, like that of an airport runway. The pavement system comprises a layer of electrically conductive paving mixture, a layer of insulative paving mixture, electrically resistive cables, an electrical power supply, sensors for measuring humidity and temperature, and a control and monitoring system. The electrically conductive paving mixture comprises a blend of naturally-occurring amorphous graphite and synthetic graphite/desulfurized petroleum coke. Preferably, the blend of naturally-occurring graphite to synthetic graphite/desulfurized produced coke is in the ratio of 2:1.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: January 13, 1998
    Inventors: Peter L. Zaleski, David J. Derwin, Walter H. Flood, Jr.
  • Patent number: RE43044
    Abstract: An electrically conductive paving system that has enhanced conductivity of the conductive graphite/asphalt layer. This is achieved by incorporating into the paving mixture a blend of two naturally occurring crystalline flake graphites, one being coarse (generally larger than 40 mesh/425 microns) and the other being fine (generally smaller than 100-200 mesh/150-75 microns). The ratio of course flake graphite to fine flake graphite may be from 1.5:1 and 1:1.5, but is preferably approximately 1:1.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: December 27, 2011
    Assignee: Superior Graphite Co.
    Inventors: Peter L. Zaleski, David J. Derwin, Walter H. Flood