Patents by Inventor Douglas I. Hoiberg

Douglas I. Hoiberg 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).

  • Two piece extruded hose
    Patent number: 4375381
    Abstract: A flexible hose and method for making same, suitable for cleaning swimming pools and general vacuum applications, having contiguous turns of an extruded helical plastic bead. The strip has thin flange and leg members for receiving the bead that provide excellent crush resistant strength in I-beam fashion while providing a high degree of flexibility.
    Type: Grant
    Filed: September 28, 1981
    Date of Patent: March 1, 1983
    Assignee: Steward Plastics, Inc.
    Inventors: Lennart L. Carlson, Douglas I. Hoiberg
  • Two piece extruded hose
    Patent number: 4337800
    Abstract: A flexible hose and method for making same, suitable for cleaning swimming pools and general vacuum applications, having contiguous turns of an extruded helical plastic bead. The strip has thin flange and leg members for receiving the bead that provide excellent crush resistant strength in I-beam fashion while providing a high degree of flexibility.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: July 6, 1982
    Assignee: Steward Plastics, Inc.
    Inventors: Lennart L. Carlson, Douglas I. Hoiberg
  • Flexible, corrugated, plastic tubing having conductive helical bead
    Patent number: 3963856
    Abstract: The combination of a flexible, thin-walled plastic tube having thereon an external, electrically conductive, helical bead which is formed of a plastic mixed with a conductive material and which is heat sealed to the plastic of the tube. Electrical conductors are electrically connected to the bead adjacent the ends of the tube. The bead is normally opaque and the tube transparent. However, the tube may also contain a conductive material and be opaque.
    Type: Grant
    Filed: November 25, 1974
    Date of Patent: June 15, 1976
    Assignee: Steward Plastics, Inc.
    Inventors: Lennart L. Carlson, Douglas I. Hoiberg