The Mechanical Handling and Storing of Material

64 THE MECHANICAL HANDLING OF MATERIAL runs in a cast-iron trough 27 in. wide by 9 in. deep. The chain is composed of cast-steel links bolted together, while to each alternate pair of links cast plates are fitted which match the section of the trough, but do not touch the sides or the bottom of it- Between the links which cairy the push-plates are placed sliding blocks which rest on a Fig. 76. Plan of Fig. 75. renewable central rail. The pins joining the small rollers (Charles Hunt’s patent) for the wear in passing round the track, and whilst on Fig. 77. Monobar and Push-Plate Conveyor. links together pass loosely through the purpose of minimising friction and the the terminals. This construction is well designed, as the chain pulls its. load at or near the centre of the push-plates,, and not, as in most cases, above. Fig. 77 shows a form of push- plate or scraper conveyor known as the Monobar conveyor, made by the Link Belt Company, with a single bar between each two scrapers, or a few shorter ones joined up in the usual way, as shown in Fig. 78. Figs. 79 and 80 is another type of push-plate conveyor, the design of the Berlin Anhaitische Maschinenbau Aktien-Gesellschaft, its special feature being that in place of the push-plates the conveying chain supports frames which resemble small bottomless boxes, the base for these frames being supplied by the conveyor trough itself. At the sides of this conveyor trough, which is practically a smooth plate, are fixed channel irons in which the guide pulleys of the sections run. For the return half of the conveyor the angle iron takes the place of the channel, the chain of this conveyor being composed of long links which nevertheless run on a specially designed and constructed circular wheel, instead of running over a polygon wheel, as is generally the case. Each link of the chain is fitted with two studs—in addition to the two ordinary pins—which fit into suitable grooves in the two terminal wheels.