Abstract: A guide rail 4 is used for movably mounting a coal hewing machine on a chain scraper conveyor 3. The hewing machine has a guide shoe 26 guided by the guide rail 4 and a chain wheel. The conveyor 3 has a conveyor channel 2 and, on the filling side, a mounting plate 1 for the guide rail 4. The guide rail 4 defines a chain passage 19 for a chain 20. The guide rail 4 also defines, in its roof side, an engagement groove 17 for the chain wheel and, in its floor side, openings 18 for the discharge of material. The chain 20 comprises long horizontal members 22 and short vertical members 21. The guide rail 4 is of box-shaped configuration and substantially rectangular cross-section. All four sides of the guide rail 4 are engaged by the guide shoe 26. On the filling side, the guide rail 4 has an upper portion in the form of an overhead bar 13 which is screwed to the lower portion 12. The vertical members 21 of the chain 20 project into the engagement groove 17.

Abstract: A scraper-chain conveyor channel section comprises a return trough and a conveyor trough. The return trough is constituted by a pair of side walls interconnected by a floor plate. A respective support bar is fixed to each of the side walls of the return trough. The support bars have portions extending upwardly beyond the side walls of the return trough. The conveyor trough is arranged between the upwardly-extending portions of the support bars. The conveyor trough is constituted by a pair of side walls interconnected by a floor plate. Respective connection means are provided for connecting the conveyor trough to each of the support bars. Each of the connection means includes a plurality of bolts and a plurality of clamping members. Each of the bolts is seated in a respective pocket in the associated support bar, and is engageable with a respective clamping member to force that clamping member into engagement with a respective clamping face on the conveyor trough.

Abstract: A conveyor channel section or pan is composed of upper and lower components each having U-shaped rolled side walls with inwardly-directed flanges and floor plates. Additional side plates fixed to the exteriors of the side walls of the lower component project upwardly alongside the side walls of the upper component. Recesses in the side plates mate with fittings on the side walls of the upper component and upstanding nuts and bolts secure the fittings in the recesses. The end regions of the pan can be provided with inclined deep pockets formed within welded-in shaped joining pieces which receive toggle-like coupling pieces used to connact adjacent pans together.

Abstract: A scraper-chain conveyor channel section comprises a pair of side walls and a floor plate extending between the side walls and connecting the side walls together. Each of the side walls has upper, lower and intermediate inwardly-extending flanges. The floor plate is connected to the intermediate flanges of the two side walls. Each of the side walls is constituted by an upper profiled bar and a lower profiled bar, each of the profiled bars being a generally U-shaped rolled section. Each of the lower profiled bars has a bottom flange and a top flange parallel to the bottom flange. The top flange of each lower profiled bar forms a support surface for the associated upper profiled bar, and constitutes part of the intermediate flange of the associated side wall. Each of the side walls is provided with a connecting bar for laterally supporting the associated upper profiled bar.

Abstract: A scraper-chain conveyor is constituted by a plurality of channel sections joined together end-to-end in such a manner as to permit limited articulation therebetween in the horizontal and vertical directions. Each channel section has a pair of side walls connected together by a floor plate. The floor plate of each channel section comprises an upper plate and a lower plate. The lower plates of the channel sections overlap one another, with vertical play, at the interfaces between adjacent channel sections. The upper plates of the channel sections abut one another at said interfaces.

Abstract: A cutter-bit assembly employs an arcuate wedge 16 to secure a cutter-bit 2 within a pocket 4 of a holder 1. An additional deformable insert or resilient backing piece 18 is also located in an arcuate gap between the cutter-bit shank and a curved surface of the holder. The insert or backing piece co-operates with teeth 19 to lock the wedge in position.

Abstract: Apparatus for controlling the position of a mineral mining machine, such as a coal plough, guided for movement back and forth along a guide employs inclined piston and cylinder units coupled via ball-and-socket joints to brackets on a conveyor supporting the guide and to connectors which are pivotably connected to the conveyor. Assemblies have parallel elongate beams which are guided on roof supports and linked to the connectors. Each connector is of multi-part construction with a main skid resting on the floor of the working and connected to the conveyor and to the associated beams. A further complementary component fits onto the main skid and the parts of the connector have curved recesses which combine to form a socket for receiving a ball of the associated unit.

Abstract: Apparatus for controlling the position of a mineral mining machine, such as a plough, guided for movement along a guide comprises inclined piston and cylinder units connected via ball-and-socket joints between connectors at the ends of elongate beams guided on roof supports and brackets on a conveyor forming or supporting the guide. The cylinder of each unit has a ball at its upper end received in a socket on one of the brackets. This upper ball has a stepped profile with a shoulder and an end region of different radii of curvature.The piston and interior of the cylinder are also stepped with innermost regions of reduced diameter. These measures reduce the overall length of the unit.

Abstract: A sprocket wheel has a plurality of equi-spaced circumferential teeth, and a plurality of pockets positioned between the teeth. A central circumferential groove in the sprocket wheel divides each of the teeth into two parts. Each of the pockets is shaped to engage with a link of a drive chain, each of the pockets being formed partially by flanks provided on each of the two parts of each of the pair of adjacent teeth defining that pocket. The flanks constitute chain link bearing faces, and each of the flanks has at least three separate bearing surfaces.

Abstract: A sprocket wheel has a plurality of equi-spaced circumferential teeth, each pair of adjacent teeth defining therebetween a pocket. The pockets are shaped to engage with the links of a drive chain. The teeth are formed with flanks at their edge faces which lead and trail during rotation of the sprocket wheel. The flanks merge with rounded faces which define bases of the teeth. The teeth are asymmetrically shaped in such a manner that the rounded faces associated with leading flanks each have a radius of curvature which is greater than the radius of curvature of each of the rounded faces associated with trailing flanks.