Patents Represented by Attorney Robert H. Robertson
  • Patent number: 4183987
    Abstract: Disclosed is a gypsum board having a kerfed edge along substantially the full length of at least one edge wherein the kerf has sidewalls inclined opposingly inwardly toward one another but do not intersect and are joined by a bottom surface of uneven profile characterized by alternately and irregularly spaced projections and depressions. The uneven bottom surface and each sidewall meet at a jagged intersection. Said kerfed edge provides enhanced strength in a direction perpendicular to the sidewalls providing improved board retention by flanged supports over that of conventional mechanically sawn kerfed edge boards. A process for providing kerfed edge gypsum board is also disclosed which comprises projecting into the board edge a first and second fine stream of aqueous liquid which incline toward one another at angles of incidence to a line perpendicular to the board edge which provides a combined angle therebetween of from about 3.degree. to about 20.degree..
    Type: Grant
    Filed: July 7, 1978
    Date of Patent: January 15, 1980
    Assignee: United States Gypsum Company
    Inventors: Lawrence T. Eby, Nels Nelsson