Patents by Inventor Letcher T. White

Letcher T. White 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: 4118072
    Abstract: A variable wall mining machine to release coal from a longwall mine face includes an articulated auger assembly made up of a plurality of side-cutting auger sections joined together by universal couplings in an end-to-end relation and coupled to a drive at one end of the assembly. A scavenger plow, supported on the mine floor, consists of sections connected together for articulated movement toward and away from the longwall mine face. Two support arms are journaled by bearings to each auger section and the other ends of the arms are pivotally supported by one of the scavenger power sections. Hydraulic actuators, supported by mine roof supports, move two adjacent scavenger plow sections together with two auger sections as a pair into sumping cuts with the longwall mine face. Other hydraulic actuators supported by the scavenger plow control the elevation of the pivotal arms and, hence, the auger assembly coupled thereto for shear cutting the mine face.
    Type: Grant
    Filed: June 6, 1977
    Date of Patent: October 3, 1978
    Inventors: Jay Hilary Kelley, Letcher T. White