The Mechanical Handling and Storing of Material

BAND CONVEYORS 93 to the loading platform at the railway station. The sacks are delivered from the end of the conveyor at a sufficient speed to slide, down a shoot and over an inclined table, practically into the man’s hands ready for stacking in the wagon. There is another siding on the other side of the conveyor, and when the table is reversed the sacks slide over for the purpose of loading into another truck on that side. This loading process can go on without being interrupted, because whilst one truck is being loaded the full one can be removed arfd an empty one put in its place. With this conveyor, twelve railway wagons can be loaded in one hour by two men. Ihe conveyor itself is a band of the ordinary construction, with the exception that it is built rather more substantially, and that the supporting rollers are 18 in. apart instead of 6 ft. The conveyor is altogether 350 ft. long, and the band is 26 in. wide. 1 his installation was the work of Messrs Spencer & Co., Ltd., of Melksbam. The “Sandvik” Flexible Steel Belt Conveyor.—This flexible steel belt, recently introduced by the Sandvik Iron Co., of Sandviken, Sweden, is undoubtedly an interesting addition to our mechanical appliances for handling material, as it has increased the application of the belt conveyor to hot and sticky substances, for which the textile belt is not suitable. The belt is similar to the steel measuring tapes known to every one, but of course of larger dimensions. It is produced from charcoal steel, cold rolled and hardened, of a thickness of f to I mm., or approximately 19 to 20 B.W.G. It has a tensile strength of about 3 tons per inch width for bands 1 mm. thick. The widths so far manufactured are 10, 12, and 16 in., the latter being at present the limit, but several bands may be used to form one wider belt. The belts are rolled in lengths of 300 m., or say 328 yds. As regards the mechanical appliances necessary to carry these steel bands—their nature varying so much from that of textile belts—the supports must of necessity differ in several essential points, the most important diversion being that the terminals must not be less than 1 m. (40 in.) in diameter, and that the supporting idlers may be greatly reduced in number, or altogether dispensed with. The necessity of the large terminals is obvious, as the constant bending of a steel band over smaller pulleys would soon destroy it, and as the bands are highly polished, and remain in that condition, a large pulley surface is necessary to afford sufficient grip on the driving terminals. The reduction in the number of idlers, or the dispensing with them altogether, seems to be one of the greatest advantages attached to the use of this new system, as these parts of a band conveyor are always the greatest source of trouble, and the weak point in an otherwise excellent appliance. In cases where no idlers are used, the steel belt runs in the bottom of a wooden trough, and owing to the polished state of the steel and the constant polishing action taking place during the working of the conveyor, no perceptible resistance is offered to the progress of the band when the speed is once up, and such a support being continuous and unbroken—contrary to the support by idlers—they form excellent conveyors for a great many purposes, particularly for out-of-door work. Another advantage not to be lost sight of is the facility with which the load can be removed at any point by a V-shaped or oblique plough, as those objections mentioned in connection with steel plate conveyors do not obtain with a smooth steel band. Last, but not least, the cost of the belt is said to be only one-third of that of a good textile rubber belt. As the life of the latter belt when exposed to the weather is considerably shortened, the Sandvik belt deserves special attention for exposed positions, as it is impervious to atmospheric influences. This is demonstrated by about one hundred installations running in Scandinavia under climatic conditions