Abstract: A mine roof support unit has a mechanism for adjusting the angular position of an auxiliary cap relative to a main cap, the auxiliary cap and the main cap forming the roof cap of the mine roof support unit. The auxiliary cap is connected to the main cap by a first pivot joint. The cap-positioning mechanism comprises a hydraulic ram and a lever acting between the main cap and the auxiliary cap. The auxiliary cap is provided with an extension arm projecting from the first pivot joint towards the main cap. One end portion of the lever is connected to the arm by a second pivot joint, and the other end of the lever is connected to a block attached to the piston rod of the ram by a third pivot joint. The cylinder of the ram is attached to the main cap.

Abstract: A mine roof support unit is constituted by two detachably connected parts. Each of the parts has a floor girder which supports a roof bar by means of a hydraulic prop. The roof support unit is intended for use at the lower end of an inclined longwall working which meets its access gallery at an angle other than 90.degree.. The detachability of the two parts enables one of these parts to be removed from the working as its face is advanced. The removed part can then be transported to the other end of the working. Each of the parts is provided with means for detachably connecting an advance mechanism.

Abstract: The invention relates to a mine roof support assembly for use in winning mineral material from a mineral mining working having a mineral face. The assembly comprises three roof support units positioned side-by-side along the face, and a goaf shield common to the three units. Each of the roof support units has a roof shield supported on a floor sill. The goaf shield is adjustable in height so as to extend from the floor to the roof of the working. Advance means are provided for advancing the roof support units towards the face, and further advance means are provided for advancing the goaf shield to follow up the advance of the roof support units. The further advance means acts between the goaf shield and the roof support units, and is such as to advance the goaf shield by a distance greater than the distance through which the advance means advances the roof support units.