Fig. 708.
Fig. 709. Fig. 710.
Details of the mechanism of the turret and turret slide are shown in [Figs. 708], [709], and [710]. [Fig. 708] is an end sectional view of the turret slide, which is traversed on its base by a segment d of a gear operating in a rack r (in the same manner as the cutting-off slide), the segment being connected by stud n to handle m. o represents the body of the slide, which is grooved at the sides to receive the gibs x, which secure it to the base p on which it slides. p is clamped to its adjusted position on the shears or bed by means of the gib, shown in dotted lines, which is pulled laterally forward by the screw s, which is tapped into the stem of the gib. The method of rotating the slide and of locking it in position is shown in [Fig. 709], which is a top view of the turret head, and [Fig. 710], which shows o removed from p and turned upside down. Pivoted to segment d is a rod e having at k a pin that as motion proceeds falls into s and rotates t, which is fast to the bottom of the turret. Upon the handle m being moved backward the segment begins its motion forward, as indicated by the arrow in [Fig. 710], thereby moving the slide backward upon the gibs by the working of its cogs into the rack r, [Fig. 708], which is attached to the base p. When the segment d has accomplished about one-half its motion the pin h, which is on the upper side of the segment d, comes in contact with the projection or lug on the side of the cam f, as shown by the arrow head in [Fig. 710], bringing the opposite side of the cam against the pin g, [Fig. 709], thereby moving it backward, compressing the spring u, and drawing the bolt l from its seat in the disc v. This operation is completed before the motion of the segment brings the pin k in contact with the ratchet-wheel t. The segment d in continuing its motion after the pin k is brought into the notch s, begins the revolution of the turret on its axis. As will be seen by the inspection of [Fig. 710], the pin h works upon a much longer radius than the projection upon the cam with which it comes in contact, and therefore, after a given part of its motion is complete, gets beyond the reach of the cam, thereby releasing its hold and allowing the bolt l, [Fig. 709], to be forced against the disc v by the expansion of the spring u, which occurs soon after the turret has commenced its revolution by the contact of pin k with the wheel t. The completion of the movement of the handle m (and the segment d) completes the revolution of the turret one-sixth of its circumference, thereby allowing the bolt l, by the further expansion of the spring u, to be forced into its next opening or seat in the disc v. The forward motion of the handle m brings the turret forward to its position at the work and restores the parts to their former positions, as shown in the illustrations.
