The Mechanical Handling and Storing of Material

CONTINUOUS TROUGH CONVEYORS band and push-plate conveyors. These travelling trough conveyors have this advantage over push-plate conveyors, that they take less power and cause less breakage to the material. With this type of conveyor, however, intermediate delivery is out of the •question. Fig. 138 shows a portion of such an endless trough conveyor with single strands and hexagonal terminals, which explains itself. 1 his class of conveyor can also be used for small inclines 'without loss of capacity—inclines of 15 being quite permissible. In fact it may be used to convey up inclines up to 45°, but in such a case the segments of the conveyor are provided with projections which prevent the material from sliding back (see pages 138 and 139). The speed of travel is 60 to 120 ft. per minute, or somewhat less than that of push-plate conveyors. There seems, however, to be no reason why they should not run at the same speed. The capacity can easily be found by multiplying the area of the trough by the speed of travel. Such conveyors have been made in lengths up to 500 ft., and for capacities of 100 tons per hour. Intermediate Discharge.—It has been mentioned above that continuous trough Figs. 139 and 140. Continuous Endless Trough Conveyor of the Link Belt Engineering Co. conveyors are only applicable for end delivery, and in order to give a greater scope to this type of conveyor several important devices have been developed. They are all based on the same fundamental principle, namely, to have two chains, one on either side of the trough (instead of underneath the trough), to which the segments of the trough are swivelled at one end, so that the loose end can be dropped for discharging, whilst during conveying this loose end is held up in some way or another. The construction of the Link Belt Engineering Co. is shown in Figs. 139 and 140. The pans forming the trough overlap, and are fitted with two pairs of wheels each. The foremost pair has a spindle or axle which runs right through and forms at the same time the pivot of the links of the chain, and this pair of wheels run on an L track. The hind wheels have a shorter axle so that they are closer to the pan, and they run on a separate flat iron bar. The latter can be interrupted at the point or points of delivery, so that each pan in succession is dipped down and discharged, the wheels being guided down and up again on to the continuation of the flat iron track by a short auxiliary track. This construction is somewhat simplified by the Jeffrey Manufacturing Co., who employ one L track only, so that the front axles remain in the normal position by the tension of the chain, whilst the back axles, which are free from the chain, allow that end of the pans to drop for discharging. A conveyor, not unlike the preceding, and which is shown in Figs. 141 and 142, is