Patents by Inventor Erik H. Madsen

Erik H. Madsen 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).

  • Copy viewer
    Patent number: 5052797
    Abstract: A copy viewer having a support stand for holding material to be copied in a viewing position and a "see-through" display device for displaying copied material directly over the material to be copied.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: October 1, 1991
    Inventor: Erik H. Madsen
  • Compactible tennis racquet
    Patent number: 4915382
    Abstract: A compactible tennis racquet having a head and a handle interconnecting by widely dispersed releaseable connections that will provide rigid coupling of the head to the handle, the connectors including handle extensions and head extensions, bolts for securing the handle extensions to the outer periphery of the head and bolts for connecting the head extensions to the handle extensions at a neck of the racquet and a hinge, provided at the neck of the racquet that provides for pivoting of the head with respect to the handle and that is locked against pivoting when the racquet is assembled for use.
    Type: Grant
    Filed: June 6, 1988
    Date of Patent: April 10, 1990
    Inventor: Erik H. Madsen
  • Numismatic detector
    Patent number: 4811040
    Abstract: A numismatic detector including a laser generator, a light collimator to form generated laser light into discrete beams, a coin holder to precisely position coins to be detected, and a film pack adapted to receive reflection of discrete light beams from the surface of the coin.
    Type: Grant
    Filed: May 8, 1986
    Date of Patent: March 7, 1989
    Inventor: Erik H. Madsen
  • Dental cleaning slurry
    Patent number: 4322207
    Abstract: A dental cleaning slurry and method of cleaning teeth comprising an aqueous suspension of particulate material having a hardness which is softer than the softest exposed part of the teeth. The slurry is directed against the teeth under sufficient water pressure for the particulate material to penetrate and dislodge any plaque or food particles that may adhere to the teeth.
    Type: Grant
    Filed: January 26, 1976
    Date of Patent: March 30, 1982
    Inventor: Erik H. Madsen
  • Hygienic spray apparatus
    Patent number: 3971136
    Abstract: Apparatus for containing and pressure spraying hygienic slurries, and then in a manner such that slurry particles are maintained in solution immediately prior to and at force feeding the same to a jet spray nozzle. Aerator means may be used to maintain particulates in suspension and, simultaneously, to develop an air pressure head for forcing the slurry out of its container toward the applicator. Various means are shown and described for maintaining slurry particles in suspension as well as for supplying under pressure such slurry to an applicator.
    Type: Grant
    Filed: May 16, 1974
    Date of Patent: July 27, 1976
    Inventor: Erik H. Madsen