Lathe: a, work; b, tail-stock; c, hand-tool rest; d, dead-centre; e, live-centre; f, face-plate; g, live-spindle; h, dead-spindle; k, head-stock; m, cone-pulley; n, driving-pulley; o, belt; p, treadle; r, treadle-hook; s, shears; t, treadle-crank.
Compound slide rest.
C, shears; E, tool carriage; H, cross slide; K, cross slide handle; L, cross feed handle; P, tool post; T, tool; D, driver; W, work.
Blanchard Lathe.
A, frame; B, carriage; C, gun stock; D, former; E, cutter-head; F, guide wheel; G, swinging frame; H, feed motion; K, shaft for revolving stock and former.
The lathe has been developed in many ways until it has become one of the most complex of all machines, adapted to tasks which even twenty years ago seemed impossible. Only two of its varieties can here be noticed, the Blanchard lathe for cutting irregular forms, and the turret lathe. An illustration, taken from an old engraving shows the Blanchard lathe as originally built for shoe-lasts. A pattern-last and the block to be carved are fixed on the same axis and are revolved by a pulley. On a sliding carriage are fastened pivots from which are freely suspended the axles of a cutting wheel, and a friction wheel, equal in diameter. The cutting wheel turns on a horizontal axle, and bears on its periphery a series of cutters. The friction wheel is in contact with the pattern-last and presses against it while in motion. During revolution, the pattern, irregular in its surface, causes the axis to approach or recede from this friction wheel; the cutting wheel in its corresponding motion removes wood from the block until a duplicate of the pattern appears. This lathe much improved and modified now turns not only gun-stocks, axe-handles and the like, but repeats elaborate carvings with precision. Ornaments for Pullman cars are produced by this machine.
Turret lathe: an early Brown & Sharpe model.
C, carriage; T, turret; L, hand lever; F, face plate; D, jaw chuck; E, tool.
