Fig. 729.
[Fig. 729] represents the automatic feed motion within the head for operating the tool bars vertically. r is the cross rail on which slides a carrying b, and permitting it to swivel at any angle by means of bolts b, whose heads pass within an annular groove, a in a. In b is carried the boring bar g, having the rack shown. p is a pinion to operate the rack. w is the feed-rod driving the worm h, which drives the worm-wheel i. This worm-wheel is provided with a coned recess, into which the friction plate c fits, so that when the two are forced together rotary motion from i is communicated to c, and thence to c′ (which is a sleeve upon c), where it drives pinion p by means of pin p′. i rotates upon and is supported by the stud j, which is threaded into c2 (the latter being also a continuation of c); hence when hand-wheel k is operated in one direction, c2 acting as a nut causes j to clamp i to c, and the tool bar to therefore feed. Conversely, when k is operated in the opposite direction, i is released from c, and may, therefore, rotate while c remains at rest. For feeding the tool bar g by hand, or for moving it rapidly, the hand-wheel m is provided, being fast to the sleeve at its section c2, and, therefore, capable of rotating pinion p. d affords journal bearing to c at its section c′. The chain from the weights which counterbalance the bars g pass over sheaves which are fixed to the piece b in which the bar slides, so that they occupy the same position with relation to the axis of the bar at whatever angle the latter may be set, and thus the counterbalancing weight is delivered upon the bar in a line parallel to its axis. As an example of the efficiency of the machine, it may be mentioned that at the Buckeye Engine Co.’s Works, at Salem, Ohio, a pulley 12 feet in diameter, weighing 8860 pounds, and having a 27-inch face, was bored and turned on one of these machines in 17 hours, taking three cuts across the face, turning the edge of the rim facing off the hub and recessing the bore in the middle of its length for a distance of several inches, the bore being in all 18 inches deep. The machine is made in different sizes, and with some slight variations in each, but the main features of the design, as clearly shown in our engravings, are common to all sizes.
[Fig. 730] represents a lathe for turning chilled rolls such as are used for paper calendering machines, and is constructed by the J. Morton Poole Company of Wilmington, Delaware.
Fig. 732.
Fig. 733.