Abstract: A shield timbering frame for timbering mines adjacent a mining face, comprises a horizontal floor-engaging skid and a breaking shield extending obliquely over the skid which is connected to the skid by a pair of longitudinally spaced, lemniscate guide rods. A roof cap member has an inner end which is pivoted to the upper end of the breaking shield and it is also braced by a piston and cylinder combination which is articulated to the breaking shield intermediate the length thereof and to the roof cap intermediate its length. At least one hydraulic ram is mounted on the skid and is engaged with the roof cap between the connection of the roof cap to the breaking shield and the connection to the additional support. The hydraulic ram is madeup of at least three telescopically interengageable extensible and retractable parts and includes pressure valve means to provide a substantially equal support pressure on the roof cap in various positional orientations of the roof cap.

Abstract: 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.