Patents by Inventor Charles W. Lehnert
Charles W. Lehnert 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: 5791109Abstract: Finishing systems and roof decks are provided which include a gypsum board having a set gypsum core faced with a fibrous mat. The gypsum core includes one or more additives which are effective in simultaneously improving the water and fire resistance of the board. In preferred embodiments, the board has sufficient water-resistant additive for absorbing less than about 10% water in an ASTM C-473 test.Type: GrantFiled: November 6, 1996Date of Patent: August 11, 1998Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5704179Abstract: Finishing systems and roof decks are provided which include a gypsum board having a set gypsum core faced with a fibrous mat. The gypsum core includes one or more additives which are effective in simultaneously improving the water and fire resistance of the board. In preferred embodiments, the board has sufficient water-resistant additive for absorbing less than about 10% water in an ASTM C-473 test.Type: GrantFiled: January 26, 1994Date of Patent: January 6, 1998Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5644880Abstract: Finishing systems and roof decks are provided which include a gypsum board having a set gypsum core faced with a fibrous mat. The gypsum core includes one or more additives which are effective in simultaneously improving the water and fire resistance of the board. In preferred embodiments, the board has sufficient water-resistant additive for absorbing less than about 10% water in an ASTM C-473 test.Type: GrantFiled: June 7, 1995Date of Patent: July 8, 1997Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5371989Abstract: An exterior finishing system for a building, including particularly an exterior insulation system, which includes a fibrous mat-faced gypsum board, preferably a board in which the set gypsum core thereof is water resistant, and preferably one in which the set gypsum core is sandwiched between two sheets of porous glass mat, with the outer surface of at least one of said mats being substantially free of set gypsum, and means for preparing the board, including control of the viscosity of the aqueous gypsum slurry from which the set gypsum core of the board is formed. Also, the use of fibrous mat-faced gypsum board as the shaft liner panel in a shaft wall assembly.Type: GrantFiled: February 19, 1992Date of Patent: December 13, 1994Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5319900Abstract: Finishing systems and roof decks are provided which include a gypsum board having a set gypsum core faced with a fibrous mat. The gypsum core includes one or more additives which are effective in simultaneously improving the water and fire resistance of the board. In preferred embodiments, the board has sufficient water-resistant additive for absorbing less than about 10% water in an ASTM C-473 test.Type: GrantFiled: May 6, 1993Date of Patent: June 14, 1994Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5220762Abstract: Gypsum-containing boards, uses for these boards, and methods for making them are provided. The board includes a set gypsum core having a fibrous glass at disposed thereon. The core includes a water-resistant additive in at least a minimum amount sufficient to impart to the board an ASTM C-473 water absorption value of less than about 10%. This additive includes organohydrogenpolysiloxane resin added with a portion of the mixing water, or otherwise added in neat form to the process for preparing the slurry.Type: GrantFiled: June 27, 1991Date of Patent: June 22, 1993Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 5148645Abstract: Glass mat-faced gypsum boards having a set core containing gypsum dihydrate and at least a minimum amount of chopped fibers, as well as other optional fire-resistant additives, are provided. The resulting boards obtain superior fire resistance properties over conventional paper-faced boards of like thickness which include a similar amount of chopped glass fibers.Type: GrantFiled: August 6, 1991Date of Patent: September 22, 1992Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall, George F. Fowler, Jr., Ray W. Hinkel
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Patent number: 4811538Abstract: A fire-resistant door comprises a core panel of mineral material, such as gypsum wallboard. A fiber mat, preferably comprising glass fibers, is at least partially embedded in each face of said core panel. An edge banding assembly disposed around the periphery of the core panel is centrally grooved to receive the panel edges. Facing sheets are affixed to the opposite sides of the edge banding assembly in spaced parallel relation to the core panel, and a spacer material at least partially fills the spaces between the facing sheets and the core panel.Type: GrantFiled: October 20, 1987Date of Patent: March 14, 1989Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, George F. Fowler, Jr.
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Patent number: 4810569Abstract: An exterior finishing system for a building. including particularly an exterior insulation system, which includes a fibrous mat-faced gypsum board, preferably a board in which the set gypsum core thereof is water resistant, and preferably one in which the set gypsum core is sandwiched between two sheets of porous glass mat, with the outer surface of at least one of said mats being substantially free of set gypsum, and means for preparing the board, including control of the viscosity of the aqueous gypsum slurry from which the set gypsum core of the board is formed. Also, the use of fibrous mat-faced gypsum board as the shaft liner panel in a shaft wall assembly.Type: GrantFiled: March 2, 1987Date of Patent: March 7, 1989Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 4748771Abstract: A fire door comprising a core and edge banding, the principal ingredients of the core being expanded perlite, gypsum and cement, the edge banding comprising a strip of natural wood, a strip of a cast mixture of which the principal ingredient is gypsum and an intervening strip of plastic laminate.Type: GrantFiled: July 30, 1985Date of Patent: June 7, 1988Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, James R. Van Dyke, Ray W. Hinkel
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Patent number: 4722866Abstract: A composition useful as the core of fire resistant gypsum board and comprising a major amount of set calcined gypsum and minor amounts of whisker fibers, glass fibers and clay.Type: GrantFiled: May 4, 1987Date of Patent: February 2, 1988Assignee: Georgia-Pacific CorporationInventors: Glenn E. Wilson, Charles W. Lehnert
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Patent number: 4695494Abstract: A fire-resistant article, for example, a fire door core comprising a major amount of expanded perlite in compressed form, an adhesive material, the major portion of which is starch, and preferably glass fibers, and a method for making the article by dry-mixing the ingredients substantially completely before water is added for the purpose of developing the adhesive characteristics of the starch.Type: GrantFiled: November 25, 1986Date of Patent: September 22, 1987Assignee: Georgia-Pacific CorporationInventors: George F. Fowler, Jr., Charles W. Lehnert
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Patent number: 4664707Abstract: A composition useful as the core of fire resistant gypsum board and comprising a major amount of set calcined gypsum and minor amounts of whisker fibers, glass fibers and clay.Type: GrantFiled: April 9, 1985Date of Patent: May 12, 1987Assignee: Georgia-Pacific CorporationInventors: Glenn E. Wilson, Charles W. Lehnert
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Patent number: 4647496Abstract: An exterior finishing system for a building, including particularly an exterior insulation system, which includes a fibrous mat-faced gypsum board, preferably a board in which the set gypsum core thereof is water resistant, and preferably one in which the set gypsum core is sandwiched between two sheets of porous glass mat, with the outer surface of at least one of said mats being substantially free of set gypsum, and means for preparing the board, including control of the viscosity of the aqueous gypsum slurry from which the set gypsum core of the board is formed. Also, the use of fibrous mat-faced gypsum board as the shaft liner panel in a shaft wall assembly.Type: GrantFiled: February 27, 1984Date of Patent: March 3, 1987Assignee: Georgia-Pacific CorporationInventors: Charles W. Lehnert, Brian G. Randall
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Patent number: 4343127Abstract: A fire door comprising a core and edge banding, the principal ingredients of the core being expanded perlite, gypsum and cement, and including, as minor ingredients, an organic binder, and having a density not greater than about 35 lbs./cu. ft. The banding comprises composite stiles and rails, each formed of a strip of wood and a strip of a cast mixture of which the principal ingredient is gypsum and including a binder and preferably also including fibers, unexpanded vermiculite and clay.Type: GrantFiled: January 15, 1981Date of Patent: August 10, 1982Assignee: Georgia-Pacific CorporationInventors: Dale R. Greve, Charles W. Lehnert