Patents by Inventor Walter H. Robertson

Walter H. Robertson 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).

  • Patent number: 5513985
    Abstract: A dental impression tray is disclosed herein having a pair of spaced-apart arcuate walls having a common radial center and wherein the opposing wall surfaces define a work area for holding a quantity of dental impression material. A thin plastic embedded fibrous membrane or sheet or a non-woven fabric material extends across the work area having its opposite edges attached to the walls and separating the walls into upper and lower wall sections. One end of the walls may or may not support a wire element while the opposite walls' ends are open. The opposing wall surfaces carry a plurality of alternate vertical grooves and rod-like projections disposed in parallel and split horizontally by the fibrous membrane. The root of each projection includes a recessed portion in order to engage with the impression material and a handle attached to an outer wall of the pair outwardly extends anteriorly therefrom. A tongue retractor structure may be integrated on an inner wall of the pair.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: May 7, 1996
    Inventor: Walter H. Robertson
  • Patent number: 5316474
    Abstract: A dental impression tray is disclosed herein having a pair of spaced-apart arcuate walls having a common radial center and wherein the opposing wall surfaces define a work area for holding a quantity of dental impression material. A thin plastic embedded fibrous membrane or sheet extends across the work area having its opposite edges attached to the walls and separating the walls into upper and lower wall sections. One end of the walls may or may not support a wire element while the opposite walls' ends are open. The opposing wall surfaces carry a plurality of alternate vertical grooves and rod-like projections disposed in parallel and split horizontally by the fibrous membrane. The root of each projection includes a recessed portion in order to engage with the impression material and a handle attached to an outer wall of the pair outwardly extends anteriorly therefrom. A tongue suppressor structure may be integrated on an inner wall of the pair.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: May 31, 1994
    Inventor: Walter H. Robertson