Abstract: A conveyor channel section has shaped side walls composed of superimposed rolled profiled strips identical in construction and shape A floor plate extends between the side walls and projects between inclined curved wall portions of upper and lower profiled strips. Longitudinal welds join the floor plate to the ends of the wall portions The wall portions merge with flanges extending inwardly of the floor plate and with ribs extending in an opposite direction outwardly of the floor plate at the level of the flanges. Spill plate holders are welded to the exteriors of the side walls between the ribs and connectors at the ends of the side walls permit adjacent channel sections to be joined together with the aid of coupling members.

Abstract: A plough guide which is composed of guide sections mounted on the working face side of the runs of channelling of a scraper chain conveyor. Toggle connections are provided on the abutting ends of the plough guide sections. Compartments accommodating the toggle connectors are situated on the rear parts of the guide sections resting against the side walls of the runs of channelling, and are preferably provided in reinforcement plates welded to angle plates. To secure the toggle connectors in the compartments the toggle connectors are provided with securing elements extending from the connector compartments into the plough guide and secured in this latter, preferably between adjacent sliding spacers. The securing elements take the form of handle-like plates which with advantage can be pivotably mounted on the toggle connectors.

Abstract: A plough box containing a chain wheel driving a chain to propel a chain used to move a plough is mounted for displacement alongside a machine frame at one end of a scraper-chain conveyor. To adjust the tension in the chain a motor is operated to drive a self-locking worm gearing which employs a worm wheel meshing with a rack fixed to the machine frame and extending in the direction of the chain.

Abstract: A plough guide which is built onto the runs of channelling of a scraper chain conveyor, has angle plates which form a slide path for the plough and which are connected by their upwardly extending sides to the runs of channelling. Sliding spacers are provided behind a covering between an upper chain channel and a lower chain channel. Covering hoods which form the covering for the channels are each pivotably mounted to a lower guide beam. The hoods can be swung over on the pivot joints towards the face in order to open the upper chain channel. The spacers are connected to the angle plates via fitting plates which are rigidly connected thereto and which extend upwards beyond the spacers. The fitting plates are provided with centering pins which engage centering apertures in the angle plates. The fitting plates can be connected to the sliding spacers and/or the angle plates by welding.

Abstract: A valve block in a mine hydraulic system contains a non-return valve which is opened when a hydraulic control signal occurs to connect a pressure fluid feed or return line to a working chamber of an appliance such as a prop. A auxiliary valve is mounted in the block and is operated manually to relieve the working chamber even if the non-return valve remains closed.

Abstract: A valve device takes the form of a multi-part cartridge with a hollow stepped housing containing a stepped rod. A control piston at one end of the rod is opposed by the force of a main spring in a main chamber remote from the control piston. A valve closure member is axially displaceable relative to the rod. The valve closure member is normally held against a valve seating but pressure on the control piston displaces the rod and causes the valve closure member to be lifted from its seating via stop faces. An auxiliary chamber in the housing leads via a connection to some consumer appliance and forms, the downstream side of the valve. A compensating piston on the rod member opposes a face of the valve closure member open to the auxiliary chamber. A further spring in the auxiliary chamber holds the valve closure member on its seating. The valve can open independently of the control piston should the pressure on the upstream side of the valve exceed the consumer pressure.

Abstract: A plough guide is composed of sections built onto the runs of channelling of a scraper chain conveyor. Behind a covering comprising covering hoods pivotable on joints, there are chain guide channels for the plough chain separated by spacers. Underneath each covering hood there is a robust guide beam which forms part of a lower guide for the plough. Each guide beam of solid rolled section is provided at each of its two ends with a recess into which is welded a stout bearing plate which on a level with the spacers. The bearing plates are equipped with open journal bearings for hinge pins positioned at the foot of the covering hood. The hinge pins are integral with hinge pieces, which are welded into recesses at the two ends of the covering hood.

Abstract: A cartridge forming a pressure measuring device is composed of main casing, a bushing detachably screwed to the casing and a coupling piece detachably screwed to the casing. The coupling piece has a plug which serves to establish hydraulic connection with some appliance to permit hydraulic fluid to act on a diaphragm configured as an integral thin wall of the coupling piece. A strain gauge sensor is mounted on the diaphragm and produces electrical signals on leads as the diaphragm deflects as a result of exposure to the pressure fluid. An amplifier serves to amplify the signals from the sensor for further processing and utilisation. The amplifier is mounted to the coupling piece with the aid of elongate conductive pins which also serve to connect the sensor leads to the amplifier.

Abstract: A machine for straightening anode rods has a portal-like frame through which the rods are transported in succession with the aid of a suspended rail conveyor. Jaws which engage on the sides of the rods are used to squeeze the rods. Beneath the jaws there is a rotatable fork which can engage and entrain with a shaped end piece on the lower end of one of the anode rods. The fork and its rotary drive is raised and lowered and guided for this reciprocal movement. An anode rod can thus be transposed through 90.degree. enabling the jaws to squeeze against all the sides of the rod.

Abstract: A mine roof support or lining frame for use in mine workings with thick inclined seams has hydraulic props mounted between an inclined goaf shield and a floor sill. The floor sill is coupled with a shifting mechanism to a frame supporting a conveyor extending along a working face of the seam. Mineral from a region of the seam extending over the support passes through an opening in the shield onto a chute which takes an inclined disposition parallel to the conveyor. Material transferred to the chute discharges in the direction of transport of the conveyor.

Abstract: An electro-hydraulic control system for a mineral mining installation has a plurality of control units (4) sub-divided into operational groups (I, II, III) with associated roof supports. Each group has its own power source (5) and power at an intrinsically safe level is provided to each of the groups independently of and in isolation from the other groups. The control units (4) are interconnected via a system data bus (13,14) in the form of conductors of multi-core cables which also carry the electrical power. A further data bus (20) independent of the system bus (13,14) is coupled to some of the units of the groups.

Abstract: An electro-hydraulic control system for a mineral mining installation has a series of valve blocks, each contain a number of valves which are operated in dependence on electrical signals to cause hydraulic appliances of roof supports to operate. To allow emergency operation, when there is a power failure or when the control system fails or is otherwise inoperative, further manually operable valves are connected by a flexible, multi-core connecting cable to the valve block of the associated support. The emergency control valves can operate hydraulically controllable direction control valves of the control system and by-pass the electrical controls. The support can then be controlled purely hydraulically, at least in its main functions, using the emergency device.

Abstract: A drive system for driving an endless chain of a mineral mining installation employs one or more chain wheels each driven by an electric motor and gearing including planetary gearing. The planetary gearing has a ring gear which can be held stationary to permit drive to be transmitted. The ring gear is coupled through a clutch, reduction gearing and a braking device to another load-balancing electric motor. Load sensors in the reduction gearing disengage the clutch in the event of overloading. The ring gear is automatically held stationary by the braking device when the load-balancing motor is inoperative. When the motor is switched on the braking device is released to permit the motor to rotate the ring gear in one direction or the other at controlled speed to vary the transmission ratio and effect load balancing.

Abstract: Apparatus for determining the tension in a chain, for example, has a pair of bearings in a housing mounting a shaft for rotation. The shaft bears a chain wheel. The bearing nearest the chain wheel is fixed in the housing while the opposite bearing is fitted into a floating ring which bears on the ends of a pair of bolts incorporating strain gauges.

Abstract: A mobile conveyor installation is composed of a carrier frame composed of channels joined end-to-end on which a scraper-chain conveyor is mounted. Drive stations are provided at the ends of the conveyor and the frame and one or both of these have driven tracks for moving the installation. The conveyor and carrier frame can adopt a curved profile. A guide beam composed of articulated plates which can be braced and locked or released serves to guide the carrier frame and the conveyor. The guide beam is connected with rams to the conveyor or the carrier frame to effect relative longitudinal movement therebetween. The guide beam is raisable and lowerable from contact with the floor either directly or via the carrier frame. The plates of the beam are coupled to a traction chain which can be tensioned or slackened with a hydraulic unit to cause the plates of guide beam to become rigid for guidance or released for movement.

Abstract: A roof support has a pair of floor sills carrying hydraulic props supporting a roof-engaging structure. The floor sills have guide rails on their adjacent sides which mate with a slidable guide block which connects to a shifting ram and thrust mechanism between the sills. The shifting ram has one of its displaceable parts, i.e. its cylinder or piston rod articulated to a thrust beam or a pair of thrust rods which link with a conveyor in front of the support. The sills are interconnected for relative vertical movement and are coupled to the other displaceable part of the ram. The guide is linked to the thrust beam or thrust rods remote from the conveyor by way of a pivot joint which resists traction but permits pivoting about an axis generally parallel to the ram and which is easily assembled and dismounted.

Abstract: A high performance drive system for a mineral mining installation employs separate main and auxiliary drives with wheels around with a chain is entrained. Each drive is composed of an asynchronous motor and spur gearing. An additional over-ride planetary gearing unit is incorporated in at least one of the drives to distribute loading as evenly as possible. The planetary gearing is operable to provide a transmission ratio which can be varied in accordance with load or rotational speed of the drive(s). The planetary gearing unit has two sets of planet wheels on a common carrier. One set of planet wheels mesh with an input sun wheel and the other set of wheels mesh with an output sun wheel. The sets of planet wheels are disposed so that one wheel of one set meshes with an adjacent wheel of the other set. A further control motor drives a pinon which meshes with the carrier and this further motor is operated in accordance with e.g. the load or rotational speed of the drive(s).

Abstract: A pressure-relief valve device employs a connector welded to the base of mining equipment equipment such as an hydraulic prop, so as to communicate with the pressure fluid in a working chamber thereof. A housing is screwed into the connector and the connector has an outflow passage leading to the surroundings. A valve composed of a fixed valve seating and a movable closure member opens and closes communication between the working chamber and the outflow passage. A spring holds the valve closure member on the seating. The valve closure member is slidably guided on part of a tappet subjected to spring force. The tappet has a piston exposed to the pressure fluid which opposes the spring force. If excess pressure occurs the tappet moves against the spring force and lifts the closure member off the seating. Once the pressure drops the tappet moves back under the action of the spring but the closure member can move more slowly to gently re-establish the valve action.

Abstract: A coal wining plough in a longwall working employs adjustable floor cutters mounted on curved carriers displaced in guideways on the body of the plough. Wedges abut on the upper ends of the carriers and are moved by hydraulic piston and cylinder units to set the position of the floor cutters and define the cutting level adopted by the plough. The units are operated with the aid of valves which respond to an electronic control device. Command signals from a remote control station are transmitted as by a radio to the plough to set up the electronic control device. Sensors on the plough provide electrical signals representing the position of the interface between the coal face and the floor and these signals are transmitted back to the control station. In a control sequence the plough runs along the seam and the sensor(s) provide signals relayed to the control station which also receives signals representing the distance moved by and/or the position of the plough.

Abstract: A valve device has a multi-part housing containing a servo-valve with a stem which is axially displaced to operate the valve and an electromagnet with a rod-like armature which is axially displaced when the electromagnet is energized. A pivotable lever translates the axial movement of the armature to the stem. For adjustment purpose, an adjustment member is in screw-threaded engagement with the lever remote from the stem. The armature is locked for rotation with the adjustment member. A regulator at the opposite end of the armature to the lever and accessible from the exterior serves to enable the armature to be partially rotated for effecting the adjustment.