Patents Assigned to Dowty (South Africa) (Proprietary) Limited
  • Patent number: 4420278
    Abstract: The roof of a heading cut by a continuous mining machine is supported by cantilevered roof beams forming part of a shield. There are at least two sets of roof beams which can be raised and lowered separately by means of hydraulic rams. When one set is lowered and the other set is raised, the lowered set can be pushed forward against the raised set by means of hydraulic rams. The cantilevered roof beams extend far enough forward to support the roof over the driving position of the continuous mining machine. The width of the shield should be less than the width of the mining machine, so that the shield can advance along the heading cut by the mining machine. Furthermore, the shield includes a conveyor for conveying the mined material from the mining machine backwards to a shuttle car or other conveying system.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: December 13, 1983
    Assignee: Dowty (South Africa) (Proprietary) Limited
    Inventors: Andrew J. Walker, John C. Watt