Abstract: A device for transferring the debris cut by a cutting machine during mining operations onto a drift conveyer comprises a pair of bridge conveyers connected to each other. The first bridge conveyer has its receiving end pivotally connected to the cutting machine with its discharge end being supported by a dirigible chassis. The second bridge conveyer is supported on the chassis of the first conveyer and pivotable about its horizontal and vertical axis. The support chassis is capable of being swivelled around a vertical axis relative to the first bridge conveyer.

Abstract: The invention refers to a movable supporting frame for supporting the roof in underground cavities, in particular for securing the excavating edge when recovering the pillars in coal mining, comprising a cap (5) supported against a base frame (1) by means of hydraulically extendable props (3) and a lemniscate drive means (4), the props (3) being pivotally connected with the base frame (1) and with the cap (5). The props (3) are essentially perpendicularly oriented relative to stratification and are linked to the base frame (1) and to the cap (5) in a universally pivotably manner, noting that preferably four props are arranged at the corners of a rectangle as seen in a plan view. The lemniscate drive means (4) is connected with the base frame (1) for swivelling movement in transverse direction relative to the plane defined by the lemniscate guides (8, 9) and is adjustably supported against any swivelling movement and is connected with the cap (5) for universal swivelling movement.

Abstract: It is an object of the invention to provide an improved shield-carrying roof support unit which has a linkage for adjusting the elevation of the cap while the pivotal connection between the cap and the shield is constrained to move substantially at right angles to the base frame. The provision of auxiliary links having pivotal connections at properly selected points results in a linkage which has a precisely defined configuration and avoids an overloading of the pivotal connections such as could occur in known shield-carrying roof support units of the same kind.

Abstract: An arrangement for tensioning a gateway conveyor in a sloping gateway during longwall working using supports having base frames which are provided with pulling and shifting hydraulic actuators, wherein in a tensioning device is provided at least at one of the supports and is connected at one end to the gateway conveyor and at the other end to a slide member which is slidably guided by the base frame of the support for a movement which is transverse to the longitudinal direction of the gateway conveyor, characterized in that the slide member which is slidably guided for a movement which is transverse to the longitudinal direction of the gateway conveyor consists of a guide frame, which is supported by the base frame against forces acting in the longitudinal direction of the gateway conveyor, the cylinder of the pulling and shifting actuator is axially immovably mounted in the base frame and its piston is connected to said guide frame, which when retracted extends on opposite sides of the pulling and shifting a