Roof support shield structure for use in an excavation

摘要

A roof-support shield structure for use in an excavation to support and shield a roof above a floor of an excavation, such as a coal mine, comprises a sill beam adapted to be supported on the floor, and an inclined shield having one end pivoted to the sill beam and an opposite end pivoted to a roof cap lever. The roof cap lever includes an elongated roof cap arm which is adapted to be positioned against the roof and a crank arm which is connected to a fluid motor such as a piston and cylinder combination to pivot it and the associated roof cap arm for the purposes of positioning the roof cap arm in association with the roof. The roof is also supported by a prop in the form of a fluid piston and cylinder combination connected between the roof cap and the supporting sill. The sill is advantageously provided with a walking and aligning mechanism for coupling it to an adjacent shield which may be shifted along the mine floor therewith.