Patents by Inventor Frank K. Stafford

Frank K. Stafford 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: 4710064
    Abstract: A mine roof support system includes a plurality of truss members each having first and second ends which are positioned in spaced relationships one behind another. There are vertically extensible props under each end of the truss members which include stabilizer sleeves to stabilize the truss members thereabove. The vertically extensible props can be extended and retracted to adjust a vertical height of the props for supporting the truss member and for moving it into and out of engagement with the mine roof. Each of the props is supported by a ground engaging means in the form of a selectively operable propulsion unit capable of being operated to produce horizontal movement of the respective props and ends of the truss members. Connecting elements beneath the ends of the truss members connect the props in tandem relationship to permit the horizontal movement of truss members and associated props relative to each other by the propulsion units.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: December 1, 1987
    Inventors: Frank K. Stafford, Robert C. Nasby
  • Patent number: 4676697
    Abstract: A mine roof support system includes a plurality of truss members each having first and second ends which are positioned in spaced relationships one behind another. There are vertically extensible props under each end of the truss member which include stabilizer sleeves to stabiize the truss members thereabove. The vertically extensible props can be extended and retracted to adjust a vertical height of the props for supporting the truss member and for moving it into and out of engagement with the mine roof. Each of the props is supported by a ground engaging means in the form of a selectively operable propulsion unit capable of being operated to produce horizontal movement of the respective props and ends of the truss members. Connecting elements beneath the ends of the truss members connect the props in tandem relationship to permit the horizontal movement of truss members and associated props relative to each other by the propulsion units.
    Type: Grant
    Filed: April 15, 1985
    Date of Patent: June 30, 1987
    Inventors: Frank K. Stafford, Robert C. Nasby