Abstract: A mine roof support comprises a support member adapted to rest on the floor of a mine gallery, a first shield projecting upwardly from the rear end of the support member, a second shield pivotally attached at its lower end to the upper end of the first shield, an expandable and contractable prop between the support member and the second shield for changing the inclination of the latter and a cap adapted to engage the roof of the mine gallery pivotally attached between its ends to the upper end of the second shield to form between the upper surface of the latter and the bottom face of the cap a wedge-shaped space directed away from the face of the mine gallery.

Abstract: An advancing excavation roof support has a base and a shield assembly above the base. The base has two base portions which are spaced from one another at its end which faces toward the face of the excavation, and a lifting member is mounted between the two base portions for pivoting about an axis. A hydraulic cylinder-and-piston unit extends between the base and the lifting member and pivots the latter about its pivoting axis between a retracted position in which the lifting member is out of contact with the excavation floor, and an extended position in which an engaging portion of the lifting member engages the excavation floor and is downwardly spaced from the base so that the one end of the base which faces the excavation face is elevated and digging thereof into the excavation floor is prevented.