. Modern mechanism, exhibiting the latest progress in machines, motors, and the transmission of power, being a supplementary volume to Appletons' cyclopaedia of applied mechanics . uniform speed, whether the table was moving in one direction or the other, and whilethe table was at rest. To prevent a chattering motion being given to the table, the use of ordinary spur andbevel wheels, gearing into each other, is abandoned altogether. In place of them there areused pinions having the contact surfaces of their teeth arranged spirally around the such pinion gears with a straight-toothed r
. Modern mechanism, exhibiting the latest progress in machines, motors, and the transmission of power, being a supplementary volume to Appletons' cyclopaedia of applied mechanics . uniform speed, whether the table was moving in one direction or the other, and whilethe table was at rest. To prevent a chattering motion being given to the table, the use of ordinary spur andbevel wheels, gearing into each other, is abandoned altogether. In place of them there areused pinions having the contact surfaces of their teeth arranged spirally around the such pinion gears with a straight-toothed rack on the table, its axis being inclined tothe axis of the table at the necessary angle, while another on the pulley shaft gears with astraight-toothed wheel on the axis of the first pinion. The angles of the teeth of thepinions are such that the pulley shaft lies parallel with the table. By means of thissystem of gearing motion is communicated to the table without shock or jar, and the pro-duction of chatters is avoided. To gain a greatly increased rate of travel on the back cut,as compared with the forward cut (in the machine illustrated it was 8 to 1), the part subject. Fig. 1.—The Sellers plauer. to reversal at high speed is kept as light as possible. The pulleys run always in the samedirection, the reversal being effected by a clutch between them, which engages alternately-with each. The table, the pinion shaft, and the clutch shaft are the parts which sufferreversal : the first two move at comparatively slow speeds, while the latter is kept as light aspossible, and special means are provided for absorbing its momentum. ^^ hen the tablestrikes the stop at the end of its stroke, it the clutch out of engagement with onepuUev, and presses it lightlv against the other, which is, of course, running in the oppositedirection. In this wav the pulley and pinion shafts are quickly checked, and the tablemoves forward, in relation to them, r,o far as to take up the backlash
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Keywords: ., bookcentury1800, bookdecade189, booksubjectmechanicalengineering
