Journal - South African Institute of Mining and Metallurgy . il Jzi. Within thi> rotat ing gear are twofeathers, corresptonding to the two opposite longitudinalgrooves In the feed screw. The turning of the crank, operating on the feed screw, andthus, through the rotating gear, upon the pinion teeth of thechuck, effects the rotation oi the chuck and steel. W v Fittings dpoN the Drill.—Entering the water con-nection (A), the water passes into the water connection cap (B)and thence into the water tube (C), which convoys it, withoutcontact with the working parts of the machine, throrifjh
Journal - South African Institute of Mining and Metallurgy . il Jzi. Within thi> rotat ing gear are twofeathers, corresptonding to the two opposite longitudinalgrooves In the feed screw. The turning of the crank, operating on the feed screw, andthus, through the rotating gear, upon the pinion teeth of thechuck, effects the rotation oi the chuck and steel. W v Fittings dpoN the Drill.—Entering the water con-nection (A), the water passes into the water connection cap (B)and thence into the water tube (C), which convoys it, withoutcontact with the working parts of the machine, throrifjh thedrill iht-0 lli sh i nk of the hollow drill steel. The water tubeis much smaller than 111«• passage through the steel. Aroundthe tube, through the sane- passage, mingled with the water,compressed air is discharged through the steel. A simpleneedle valve (hand wheel ot winch is shown in cut) controls thedischarge of water. Oct. 1907 E. M. Weston ,„// Stop, 113 The large Leyner machine is worked by a pistonvalve (Fig. II.), and the Little J , axial. valve, and the Gordon drill by a piston or spool !valve at right angles to piston. They may againe. divided into those drills that employ an anvil b,ock to take up and transmit the blow of thehammer, as in both Leyner machines and the<•< I drill, and nearly all the n trike the blow directly on the teel il i If. The) mighlal o be divided intomachines, bul I will return to thiThe favourite small machine in America•h those without ,•?? yalve, which strike the steel direct. Their advant igeconsists in their extreme simplicity and lightiThej transmit the force of this blowmoredito the rock, having to overcome the inerttli drill steel only; but tiny work generally ona short stroke and rely on a high velocity Imomentum to the hammer, which is liglotherwise trouble might occur through the burri_ up of the shank of the drill bit, and, as theyften worked held in the miners hand only,heavy blows would cause too much jar on
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Keywords: ., bookcentury1800, booksubjectmetall, booksubjectmineralindustries
