Abstract: The invention relates to a scraper chain for scraper chain conveyors, particularly for use in mining, with vertical chain links flattened in their longitudinal legs, which are integrally joined by nose-parts of circular cross-section, while the horizontal chain links have a constant circular cross-section all round. The scraper chain has a strength which is at least equal to that of a size 48 standard round link chain. The horizontal links serving as scraper connection have a pitch which is at least 10%, and preferably about 15%, greater than the pitch of the vertical links. The outer width of the horizontal links is at least 30% greater than the outer width of the vertical links. For the scraper chain according to the invention, sprockets whose dimensions are the same as those for scraper chains of considerably lower strength may be used.

Abstract: It is provide in a powered support frame, for large seam thicknesses with controlled gap sealing, that double acting gap cylinders (16, 27, 30) of several gap sealing elements (15) on a powered support frame are connected to a common pressure feed line (34, 37, 39) and to a common pressure return line (50) and are impacted with a uniform pressure when the gap sealing elements are to be extended.

Abstract: A valve arrangement (10) for hydraulically actuated machinery installations, especially for powered support assemblies in underground mining, with hydraulically actuated working valves (12, 13, 14) to control hydraulic cylinders (11) or other hydraulically actuated machinery units of the machinery installation and with pilot valves (15) controlling the working valves. In order to avoid the pilot valves (15) and working valves (12, 13, 14) entering an unstable operating condition in the event of a falling off of pressure in the hydraulic fluid supply to the valves, and opening and closing in an uncontrollable and undesired manner, the pilot valves (15) are attached to their own pressure medium supply (17), separate or separable from the hydraulic fluid supply (20) to the working valves (12, 13, 14), so that pressure variations in the hydraulic fluid supply circuit do not affect the pressure medium for the switching of the working valves (12, 13, 14), but the pressure in them is maintained largely constant.

Abstract: A chain drum arrangement for a scraper-chain conveyor has a chain drum, which is connected at its end regions to two mutually aligned chain drum shafts mounted rotatably in a machine frame and, when uncoupled, can be removed from its fitted position transversely to its longitudinal axis from the machine frame. The chain drum shafts have terminal shaft journals projecting inwardly from side wall sections of the machine frame whereas the chain drum is provided, at its end regions, with substantially radially extending pockets with which it can be plugged onto the shaft journals and locked non-rotatably thereto The shaft journals are peripherally flattened to engage positively in the pockets and have external regions which act as locking claws fitting into undercut regions of the pockets when the drum is partly rotated around the journals. Closure members with screwed-on releasable locking plates serve to lock the drum on the journals.

Abstract: The double telescopic prop comprises an outer cylindrical casing tube 1, an inner tube 2 which is displaceable therein and a piston rod 3 which can be extended therefrom. The hydraulic fluid for extending the two prop stages is conveyed through a connection 14 to the piston 5 of the inner tube 2 and is conveyed via a bottom valve to the piston 7 of the piston rod 3. The prop is retracted if hydraulic fluid flows via the connection 17 into the outer annulus 11 between the cylindrical casing tube 1 and the inner tube 2. A size ratio of 8.8:1 at most, which is favourable for the retraction of the prop, exists between the area of the inner tube 2 and the ring area of the annulus 11.

Abstract: In the plough pick arrangement according to the invention for mining ploughs or coal ploughs, the plough pick is held in the socket of a pick holder. On that side of the pick holder which is leading in the working direction of the plough pick a pick lead-through opening is provided through which the pick can be inserted by its shank until it reaches a rear stop and is retained by a securing device. The pick can be removed from the socket through the same opening, after the securing device has been released, when pick replacement is necessary. This makes it possible to insert the pick into and remove it from the pick holder, not from the working side, but from the front of the holder. The pick holder and the pick are preferably provided with co-operating bearing and guiding faces which are inclined at an oblique angle to a plane parallel with the working face so that the cutting bit of the pick moves away from the working face when the pick is removed.

Abstract: In the driving and guide arrangement according to the invention, the drive chain in a chain channel bounded by a guide rail and a rear wall is supported only on series of spaced, narrow support elements at least some of which may form connecting plates welded between the rear wall and the guide rail. As the narrow support elements are spaced apart from one another, fines getting into the chain channel from above readily drop between them, and emerge freely through face side and gob-side discharge openings in the chain channel. Caking of fines in the chain channel is largely prevented in the arrangements, which are fabricated as welded constructions and are therefore particularly economical to produce.

Abstract: The body (1) of the hydraulically trippable check valve for mine support hydraulics according to the invention contains: a valve poppet (13) biased in the closing direction by a spring (22); a control piston (17) which can be acted on by a hydraulic control pressure, causing the poppet (13) to be lifted off its seat (11); and an initial relief valve (20, 21) which can be tripped by the control piston (17) against its spring closing force. Matters are arranged so that the control piston (17) which can be acted on by the hydraulic control pressure is dimensioned in terms of piston surface area (17') so that the poppet (13) of the check valve cannot be lifted off its seat (11) until the opening of the initial relief valve has caused a predetermined initial relief of operating pressure on the high-pressure side.

Abstract: The scraper chain belt according to the invention is preferably intended for scraper chain conveyors of long conveying lengths and correspondingly high drive outputs, and consists of vertical and horizontal chain links (1, 2) which are suspended articulated within one another, wherein the vertical chain links (1) advantageously have a surrounding out-of-round cross-section which is provided with a flat (6) on its external contour, whilst the horizontal chain links (2), which serve for the scraper connection, are formed in the manner of webbed chain links having a central web (12) which passes transversely through their internal opening. The scraper connection is preferably effected with the aid of studs (19) which are fixedly disposed on the scrapers (13) and which point towards the scraper base, and which pass through the insertion openings (20) in the central webs (12) of the horizontal chain links (2), wherein the scraper connection can be secured with the aid of locking elements.

Abstract: A method for determining the active power (P) of asynchronous electric motors of winning and conveying equipment in underground mining. According to the invention, particularly easy and accurate determination of the instantaneous active power of the motors is obtained by storing the individual motor characteristic (P(n); M(n)) of each motor in a computer, by detecting the instantaneous speed (n, n') of the motor with the aid of a tachometer and by comparing this speed with the characteristic stored in the computer, the active power being derived from the torque value or power value assigned to the detected instantaneous speed, as stored in the computer. This particularly rapid and simple calculation of the power value does not require any readings to be taken at the power supply to the motors.

Abstract: This invention relates to a chain drum arrangement for a central or double central scraper chain conveyor, comprising a divided chain wheel, the shell-type chain wheel segments of which are attached, locked in rotation and detachably, via an axial splined portion to the shaft, wherein the chain wheel is secured in its installed position on the shaft by means of locking rings disposed on both sides and at least one of these two locking rings consists of a divided locking ring which can be taken off radially from the shaft in order to remove the divided chain wheel from the shaft. According to the invention, the divided locking ring is disposed as an intermediate ring between the divided chain wheel and a hollow journal which receives the respective shaft bearing and which projects axially from the respective side cheek of the machine frame into the interior space thereof, which results in a narrow mode of construction of the divided locking ring.

Abstract: The guide shoe according to the invention for cutting machines with a pintype drive has an insertion pocket in which a coupling piece engages from above, which coupling piece is arranged on a guide arm of the cutting machine and to which the guide shoe is attached so as to be pivotable by means of a transverse bolt which passes through the insertion pocket. In order also to allow the guide shoe to be pivotable about a vertical axis, the coupling piece is provided with an upright vertical journal which engages from below in a corresponding bearing hole on the guide arm. In this case, in a preferred embodiment, the bearing journal is decoupled from transverse forces which are transmitted between the guide arm and the guide shoe via a transverse-force piece arranged on the coupling piece.

Abstract: A conveyor chute for chain scraper conveyors, in particular stope conveyors, having a bottom aperture provided in the conveyor bottom forming an inspection or repair aperture and closed by way of a closure panel during the conveying operation. The closure panel is guided in slot-shaped apertures of the two side profiles of the conveyor chute by way of their opposite panel edges and secured against displacement by a locking device. The two side profiles of the conveyor chute are each formed of two profile strips in superimposed array which are not interconnected to the conveyor bottom in the region of the bottom aperture. The two side profiles form the slot-shaped apertures in which the locking of the closure panel in the closed position takes place only on one of the two side profiles.

Abstract: In the drive system according to the invention for a cutting machine which can be moved along a chain conveyor and has a pin drive chain arranged in a chain receptacle of the chain conveyor, the pin drive chain is attached at each of its two ends to a hydraulic tensioning cylinder device, with the aid of which the chain slackness which forms in the pin drive chain can be compensated. At the same time, holding devices, such as end stops, are provided in the region of the tensioning cylinder devices, which holding devices support or fix the chain section of the pin drive chain which is respectively under tensile loading.

Abstract: The invention relates to a scraper-chain assembly for scraper-chain conveyors, in particular central or double central scraper-chain conveyors, having a scraper connection to horizontal chain links of the single-strand or two-strand chain assembly. Vertical chain links hooked into the horizontal chain links are provided with longitudinal limbs which have a non-round cross-section, and whose thickness dimension is smaller than that of nose parts of these chain links that connect the longitudinal limbs. For the scraper connection, the scrapers have coupling and locking pins, which extend through internal openings of the horizontal chain links, between the hooked-in vertical chain links and which protrude from the internal openings to form locking pieces which serve to secure the scrapers.

Abstract: A chain drum arrangement for a central or double central scraper chain conveyor which includes a divided chain wheel and shell-type chain wheel segments which are attached and locked in rotation to or detachably from the shaft. The chain wheel is secured in its installed position on the shaft by ring parts disposed on both sides of the chain wheel, and at least one of these ring parts has a divided locking ring which can be taken off radially from the shaft in order to take off the divided chain wheel from the shaft.

Abstract: A conveyor pan connection of a scraper chain conveyor which conveyor pans having side profiles having profiled strips which form guide channels for scrapers and having outwardly directed flange strips. The conveyor pan connection includes coupling plates which are welded in between the outwardly directed flange strips at the ends of the side profiles of the conveyor pans, a first coupling plate projecting from an end of a first conveyor pan over a joint between conveyor pans and a second coupling plate at the opposing end of a second conveyor pan is set back with respect to the joint.

Abstract: A drive and transfer station for an underground mining installation employs a frame with spaced apart walls over which material is transferred between scraper-chain conveyors one arranged along a long wall mineral face working and the other arranged along an access roadway. The scraper-chain assembly of the face conveyor is driven by drive assemblies on opposite sides of the frame which drive a rotatable chain drum.At least one of the drive assemblies has a coupling in a gear box with a shaft which can be displaced axially with an adjusting device to drivably connect with the drum or to be released from the drum.

Abstract: A shield support frame is constructed from main shoes (5) on the ground, hydraulic props (6) and a main canopy (7) borne by them and a gob shield (8) borne on guide links (10). On the face side, there is a front cantilever (24) linked so as to be adjustable in height from the main canopy (7), on which a sliding canopy (25) is guided so as to be able to slide in the direction of the face. On the ground, an adjustable baseplate (21) is arranged at a distance in front of the main shoes (5) and connected via a horizontal joint axle (22) to the extending part of the shifting gear (3). Front assembly props (23) mounted on the adjustable baseplate (21) support the sliding canopy (25). The tip of the plate of the adjustable baseplate (21) is lifted from the ground during forward movement.

Abstract: A mineral winning installation employs a shearer which is moved along a scraper-chain conveyor compound of individual pans mounted end-to-end. the shearer extends over the conveyor and is guided by guides provided at both sides of the conveyor. The body of the shearer has a driven chain wheel which meshes with an open-link chain serving as a rack abutment and laid on a bed alongside the side walls of the conveyor pans adjacent the mineral face. The side walls of the pans have upper and lower flanges which have strip-like projections directly outwardly from the pans. The chain is retained by the strip-like projections of the upper flanges of the pan side walls which overlap one side of the horizontal links and detachably hold-down strips which overlap the other side of the horizontal links. the hold-down strips are mounted for swivelling to release the chain links are detachably mounted to the support bars fixed to the support members.