Abstract: A mineral mining installation comprises a roof support unit and an advance mechanism. The roof support unit has a floor sill constituted by two floor girders. The advance mechanism comprises a hydraulic advance ram, the advance ram having a relatively-displaceable cylinder and a piston rod, and a device for selectively limiting the working stroke of the ram. The stroke-limiting device comprises a stop fixed to the cylinder of the advance ram, and an adjustable stop member which is mounted on the side wall of one of the floor girders.

Abstract: A mobile mine roof support assembly has three mine roof support units coupled together by a common transverse beam. Roller devices are mounted beneath the floor sills of the support units. The roller devices are spring biased away from their floor sills so that they can lift the floor sills away from the floor of a working when the assembly is to be moved. At least one roller device of each support unit is a steerable roller device so that the assembly can be steered round bends. Each steerable roller device is pivotally mounted on its floor sill about a vertical axis, and is provided with an associated steering device. The steerable roller devices are preferably coupled together by means of a common steering device.

Abstract: A mine roof support has a goaf shield with a lemniscate guide system linking the shield to floor-engaging skids. A walking-mechanism is disposed in a channel between the floor skids. In order to prevent rubble or goaf material from penetrating into the channel the guides of the lemniscate system have connections which are spaced one above the other and to which one or several screen plates can be removably and replaceably attached with the aid of push-in locking-bars. The screen plates also advantageously serve to keep the floor skids apart by a minimum distance to prevent jamming of the walking mechanism.

Abstract: A mine roof support has a main roof bar which is pivotably connected to an auxiliary forwardly-extendible bar. At least one piston and cylinder unit serves to swing the auxiliary bar about the main bar to bring the auxiliary bar into a roof-contacting position aligned with the main bar or into a stowed position beneath the main bar or into some intermediate position. One or more pivotable guide levers connect the auxiliary bar to the piston and cylinder unit. A guide member is also connected to the unit and slidably locates in longitudinal guideways formed in ribs or the like at the underside of the main roof bar.

Abstract: A mineral mining installation comprises a mine roof support assembly and apparatus for drilling bores. The roof support assembly comprises a plurality of roof support units positioned side-by-side, and the drilling apparatus comprises a drilling device which is movably guided on a track associated with the roof support assembly. Each of the roof support units has at least one roof bar. The track is arranged on the underneath sides of the roof bars of the roof support units. The drilling device is pivotally mounted on a trolley which is movably guided on the track.

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 roof support assembly is constituted by a plurality of roof support units and a plurality of advance mechanisms. The units are positioned side-by-side along a longwall face of a mineral mining working. Each advance mechanism comprises a pair of generally parallel hydraulic advance rams and a guide rod system constituted by a pair of resilient generally parallel guide rods. Each guide rod system is attached, at one end, to a conveyor extending along the longwall face. The other end of each guide rod of each advance mechanism is attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a respective floor girder of a roof support unit. The slide pieces are attached to the piston rods of the hydraulic advance rams. The cylinders of the hydraulic advance rams are attached to one of the adjacent floor girders, and the slide piece attached to the piston rod of hydraulic advance ram is attached to the guide rod system.

Abstract: A mine roof support has a main roof bar which is pivotably connected to an auxiliary forwardly-extendible bar. A piston and cylinder unit serves to swing the auxiliary bar about the main bar to bring the auxiliary bar into a roof-contacting position aligned with the main bar or into a stowed position beneath the main bar or into some intermediate position. Pivotable guide members connect between the main and auxiliary bars respectively and a pivot joint linked to the piston and cylinder unit. The guide members can take the form of simple straps or levers but an additional piston and cylinder unit can also be used as one of the guide members.

Abstract: Apparatus for controlling the position of a mineral winning machine, such as a plough, movable along a guide at one side of a scraper-chain conveyor employs cantilevered beams extending between the conveyor and roof supports as known per se. Brackets are provided at the goaf side of the conveyor and these brackets are pivotably coupled to the cantilever arms by way of flat pan-like components. Upstanding piston and cylinder units are positioned close to the conveyor goaf side wall preferably within protective walls of the brackets. These units are pivotably connected at their upper ends to the brackets and to extensions of the pan-like components so that the beams are effectively pivotably coupled to the units at positions offset towards the conveyor relative to the pivot connections with the brackets. The space between the conveyor and the supports is relatively unrestricted. The units are extended or retracted to tilt the conveyor and the guide whereby to control the cutting position of the machine.