The Mechanical Handling and Storing of Material

COAL FACE CONVEYORS r63 Greaves leads the return strand of the chain back to the head end in a separate com- partment in a very ingenious way, so that only a minimum of space is required. The Allardice Coal Face Conveyor, Fig. 217, consists of an endless chain with trough, extending the full length of the face, sliding over the floor, and manipulated by a haulage gear. 1 he return of the chain is overhead, being supported about every 9 ft. A suitable tension gear is provided at the top end of the face. The chain consists of links made from flat bar, 9 in. pitch, with suitable scrapers arranged every 3 ft., which pass over sprocket wheels at each end of the face. The sprocket wheels are driven by the haulage gear through treble reduction machine-cut gearing which is placed in the main road, which is made wide enough for a double road. Fig. 217. The Allardice Coal Face Conveyor. 'Ehe chain for the haulage gear passes over this road, and the coal is delivered into tubs without any special devices. The main road is driven 15 to 20 ft. ahead of the coal face to allow of empty tubs being brought forward, so that no delay takes place in their filling. In some coal face conveyors, including that of Ritchie & Sutcliffe, textile bands are used as scrapers which are supported by rollers, or slide on the bottom of the trough. Class D.—Appliances which propel the material, either by a simple reciprocating motion down an inclined trough or by a more complex motion on the level, and even slightly uphill. I he latest development of coalface conveyors is the reciprocating trough oj Rutsche^ which, owing to its great simplicity, promises to make rapid headway, for if simplicity is always desirable in all machinery, it is especially so for appliances at the This conveyor, having been introduced in German collieries first, the German name Rutsche (plural, Kutschen) is often used in this country, but the Author suggests “Jog-trough ” as an expressive English name.