Patents by Inventor Dennis M. Riggs
Dennis M. Riggs 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).
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Patent number: 5551451Abstract: The present invention is directed to a composition suitable for making fuel elements for smoking articles, which comprises at least about 50 weight percent, preferably at least about 60 weight percent, and most preferably at least about 70 weight percent powdered elemental carbon, preferably carbon obtained from the controlled carbonization of hardwood paper pulp. The fuel composition also comprises at least about 1 weight percent, preferably at least about 5 weight percent, and most preferably at least about 10 weight percent of a suitable binder. The fuel composition of the present invention can include at least about 3 weight percent, preferably at least about 5 weight percent, and most preferably at least about 8 weight percent powdered graphite.Type: GrantFiled: April 19, 1995Date of Patent: September 3, 1996Assignee: R. J. Reynolds Tobacco CompanyInventors: Dennis M. Riggs, Dwayne W. Beeson, Billy T. Conner
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Patent number: 5415186Abstract: Disclosed is a stabilized substrate composition for smoking articles, particularly cigarettes. In general, the stabilized substrate composition comprises an admixture of a binder and an aerosol forming material which plasticizes the binder, together with optional fillers and/or base materials. In the stabilized substrate compositions of the present invention the relative amounts of binder and aerosol former depend particularly on the situation in which the substrate composition is used. In general, the ratio of aerosol former to binder is between about 3:1 and about 40:1. When the stabilized composition is used on a base material such as tobacco cut filler, the ratio of aerosol former to binder should be at least about 15:1, and preferably is from about 25-35:1, with a maximum ratio of about 40:1. If the composition is formed into a cast sheet, the minimum ratio is about 3:1, the preferred ratio is about 8:1, and the maximum ratio is about 10:1.Type: GrantFiled: April 16, 1993Date of Patent: May 16, 1995Assignee: R. J. Reynolds Tobacco CompanyInventors: William J. Casey, III, Jeffery S. Gentry, Alvaro Gonzalez-Parra, Aju N. Lekwauwa, Dennis M. Riggs, Gary R. Shelar, Kenneth W. Swicegood, Ronald O. Wagoner, Jeffrey A. Willis, Walter R. D. Young, Jr., Kelly K. Hutchison
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Patent number: 5396911Abstract: Disclosed is a stabilized substrate composition for smoking articles, particularly cigarettes. In general, the stabilized substrate composition comprises an admixture of a binder and an aerosol forming material which plasticizes the binder, together with optional fillers and/or base materials. In the stabilized substrate compositions of the present invention the relative amounts of binder and aerosol former depend particularly on the situation in which the substrate composition is used. In general, the ratio of aerosol former to binder is between about 3:1 and about 40:1. When the stabilized composition is used on a base material such as tobacco cut filler, the ratio of aerosol former to binder should be at least about 15:1, and preferably is from about 25-35:1, with a maximum ratio of about 40:1. If the composition is formed into a cast sheet, the minimum ratio is about 3:1, the preferred ratio is about 8:1, and the maximum ratio is about 10:1.Type: GrantFiled: November 27, 1991Date of Patent: March 14, 1995Assignee: R. J. Reynolds Tobacco CompanyInventors: William J. Casey, III, Jeffery S. Gentry, Alvaro Gonzalez-Parra, Aju N. Lekwauwa, Dennis M. Riggs, Gary R. Shelar, Kenneth W. Swicegood, Ronald O. Wagoner, Jeffrey A. Willis, Walter R. D. Young, Jr.
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Patent number: 5211684Abstract: The present invention is directed to cigarettes and other smoking articles which contain a catalytic composition, preferably as part of the fuel element, that substantially decreases the amount of carbon monoxide contained in the mainstream smoke during smoking. The present invention also relates to the catalyst-containing carbonaceous fuels themselves, as well as to methods of making such carbonaceous fuels. Fuel elements which contain a catalytic composition in accordance with the presentation are especially useful in smoking articles having an aerosol generating means which is physically separate from the fuel element.Type: GrantFiled: January 10, 1989Date of Patent: May 18, 1993Assignee: R. J. Reynolds Tobacco CompanyInventors: Michael D. Shannon, Richard L. Lehman, James L. Resce, Olivia P. Furin, Joseph T. Meers, Dennis M. Riggs, Ernest G. Farrier
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Patent number: 5178167Abstract: It has been found that the addition of specific levels of sodium, advantageously in the form of sodium carbonate, to low sodium level binder, e.g., ammonium alginate, containing carbonaceous fuel compositions results in dramatic changes in the performance of both the fuel element themselves and, cigarettes (or other smoking articles) incorporating the fuel elements. These performance differences include variation in the yields of aerosol and/or flavorants. The addition of sodium carbonate to the fuel elements greatly improves the smolder rates and also improves puff calories, without overheating the cigarette, thereby resulting in substantial improvements in total (and puff by puff) aerosol yield.Type: GrantFiled: June 28, 1991Date of Patent: January 12, 1993Assignee: R. J. Reynolds Tobacco CompanyInventors: Dennis M. Riggs, Alvaro Gonzalez-Parra
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Patent number: 4576811Abstract: A spinnerette for mesophase pitch includes a spinnerette body with a plurality of mesophase pitch fiber forming channels through it. Each bore includes a capillary bore section at the outlet side of the spinnerette body, a wider diameter counter bore at the inlet side and an entrance between the wider bore and capillary bore sections with the entrance wall defining a relatively flat angle for increasing the proportion of tangential cross-section pitch fibers, as compared with radial cross-section fibers.Type: GrantFiled: July 16, 1985Date of Patent: March 18, 1986Assignee: E. I. Du Pont de Nemours and CompanyInventors: Dennis M. Riggs, Hugh E. Redick
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Patent number: 4504454Abstract: This invention features an improved spinning process for pitch-based carbon fibers, that will provide a continuous pitch-based carbon fiber having a uniform pattern of graphite crystallites over a substantial portion of the fiber cross-section and/or aligned along the fiber axis in the form of undulating ribbons. Continuous carbon fibers having the preferred orientation of graphite crystallites will exhibit greater mechanical properties.Type: GrantFiled: March 28, 1983Date of Patent: March 12, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventor: Dennis M. Riggs
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Patent number: 4395299Abstract: Bulk pieces of graphite bonded with a graphitizable binder comprising a lid crystalline component of pitch, which softens at about 240.degree. C. and becomes very fluid at about 300.degree. C. to about 500.degree. C. The bonded graphite pieces appear as a monolithic material even under 1000.times. magnification. The bonding is effected under vacuum or in an inert atmosphere at temperatures of from about 700.degree. C. to about 3000.degree. C., usually about 1000.degree. C. to about 1500.degree. C., under pressure of from about 20 psi to about 1000 psi applied in a direction normal to the bonding surface.Type: GrantFiled: August 21, 1981Date of Patent: July 26, 1983Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Dennis M. Riggs, Edward L. Harvey
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Patent number: 4331620Abstract: Heat treated pitches, especially pitches containing either isotropic or anisotropic phases as well as mixtures thereof, are spun by subjecting the pitch at spinning temperatures to shearing forces while simultaneously spinning the pitch.Type: GrantFiled: February 25, 1980Date of Patent: May 25, 1982Assignee: Exxon Research & Engineering Co.Inventors: Russell J. Diefendorf, Dennis M. Riggs
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Patent number: 4208267Abstract: An improved process for preparing liquid-crystal containing pitches comprises extracting carbonaceous isotropic pitches with an organic solvent system to provide a solvent insoluble fraction which when heated for 10 minutes or less and to temperatures in the range of about 230.degree. C. to 400.degree. C. will upon polarized light microscopy examination of cooled samples display greater than 75% of an optically anisotropic phase.Type: GrantFiled: May 5, 1978Date of Patent: June 17, 1980Assignee: Exxon Research & Engineering Co.Inventors: Russell J. Diefendorf, Dennis M. Riggs