Patents Represented by Law Firm Owen, Wichersham & Erickson
  • Double wall fire proof duct
    Patent number: 5298299
    Abstract: A composite plastic duct structure comprised of an outer layer of fabric material impregnated with a fire-resistant resin material and an inner liner layer of chemically corrosion resistant resin material impregnated with a fabric material. The invention includes a method wherein multiple wrappings of resin impregnated material are wound on a mandrel to form the inner and outer layers.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: March 29, 1994
    Inventor: Lawrence E. Shea
  • Piano with sound-enhancing system
    Patent number: 4058045
    Abstract: A piano having a sound-enhancing system incorporating transducers, amplifiers and loud speakers, all incorporated into or upon the piano.
    Type: Grant
    Filed: February 5, 1976
    Date of Patent: November 15, 1977
    Assignee: Solosonic
    Inventors: Robert Parry Jennings, Kenneth Thomas Aaroe