Roof supports

摘要

To increase the height of operation of a shield type roof support an attachment is fitted to the floor sill or to each of a pair of spaced-apart floor skids. The attachment has side walls with bores for receiving pivot pins used to link the attachment to the floor sill or skid and to guide levers connected to the goaf shield. A transverse body extends between the side walls and defines a socket for forming part of a ball-and-socket joint connecting the attachment to a hydraulic prop. The side walls of the attachment have under surfaces which rest on a support surface of the skid or sill near the working face.