. Machinery for metalliferous mines : a practical treatise for mining engineers, metallurgists and managers of mines. Fig. 127.—Clamps for Ingersoll Drill. about ^12, and the weight from 280 lb. to 300 lb. The double-screwcolumn costs about 30^-. Fig. 128.—New Pattern Clamp, used for Holding the Sergeant Drill upon the Arm or Column. The column or bar is, however, not suitable for mounting drills, exceptwhere the sides of the level are fairly close to each other, and, of course,for outside work it is altogether useless, so that some form of tripodmust be used, the legs of the tripod car
. Machinery for metalliferous mines : a practical treatise for mining engineers, metallurgists and managers of mines. Fig. 127.—Clamps for Ingersoll Drill. about ^12, and the weight from 280 lb. to 300 lb. The double-screwcolumn costs about 30^-. Fig. 128.—New Pattern Clamp, used for Holding the Sergeant Drill upon the Arm or Column. The column or bar is, however, not suitable for mounting drills, exceptwhere the sides of the level are fairly close to each other, and, of course,for outside work it is altogether useless, so that some form of tripodmust be used, the legs of the tripod carrying weights in order to insure SUPPORTS FOR ROCK DRILLS. j85 the rigidity and solidity of the drill. A convenient form, and onerepresentative of many others, is shown in fig. 129. The legs can bemoved in any direction and are telescopic, so that the tripod can be fixedin any position on the most irregular ground, and the drill, adjusted tobore holes in any required direction, from vertical to horizontal. The price of such a tripod, complete with weights, is, for a 3-in. drill,about ^15. For the driving of tunnels of large section, such as railway tunnels,
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1902
