Patents by Inventor Hal I. Dunham

Hal I. Dunham 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: 4453770
    Abstract: An improved system and method for relocating a selected layer of overburden, such as a layer of unconsolidated soil, in a strip mining operation are provided. The system employs an excavator, an intermediate belt wagon with at least two slewable conveyors, and a cross-pit conveyor having a long cantilevered conveyor pivotably supported on a mobile base; with all of said equipment being preferably based on the highwall side of the pit. According to the method, the area to be stripped is divided first into a series of large rectangles aligned parallel to the pit, with each rectangle being further divided into a series of narrow strips also parallel to the pit. The area is then progressively stripped beginning with the nearest strip of a first rectangle and proceeding with the next adjacent strip until the first rectangle is completed and then proceeding in like manner with each successive rectangle.
    Type: Grant
    Filed: November 16, 1981
    Date of Patent: June 12, 1984
    Assignee: Dresser Industries, Inc.
    Inventors: Thomas H. Dalrymple, Hal I. Dunham