Patents by Inventor Wilhelm Pramstraller

Wilhelm Pramstraller 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).

  • Illuminating apparatus with a light control channel for photographic enlarging equipment with a rotatable picture stage in the plane of the negative to be copied
    Patent number: 4227804
    Abstract: An illuminating system for use in a photographic enlarging apparatus having first and second light control channels is disclosed. The light control channels receive and transmit light from a light source; the light exit end of the first light control channel has a diagonal that is less than the longest side of the cross-section of the light entrance end of the second light control channel. A picture stage for receiving and supporting a negative to be projected is secured to the light exit end of the second light control channel. The second light control channel and the picture stage are mounted for unitary rotational movement about an axis normal to the plane of the negative.
    Type: Grant
    Filed: March 26, 1979
    Date of Patent: October 14, 1980
    Assignee: Durst AG Fabrik Fototechnischer Apparate
    Inventor: Wilhelm Pramstraller
  • Photographic enlarging apparatus
    Patent number: D260773
    Type: Grant
    Filed: January 29, 1979
    Date of Patent: September 15, 1981
    Assignee: Durst A.G. Fabrik Fototechnischer Apparate
    Inventor: Wilhelm Pramstraller