[Fig. 1535] represents a machine of this class. The tool-carrying slide a, in this case, operates in guideways provided in b, the latter being fitted to a slideway running the full length of the top of the frame m. The base slider b is fed along the bed by means of a screw operating in a nut on the under side of b, this screw being operated once during each stroke of the tool-carrying slide a, by means of a pawl feeding arrangement at f, which corresponds to the feeding device shown in [Fig. 1501].

Two vertical frame pieces d, d are bolted against the front face of the machine, being adjustable along any part of the bed or frame length, because their holding bolts have heads capable of being moved (with the frame pieces d) along the two T-shaped grooves shown, their T-shape being visible at the end of the frame or bed. To frames d are bolted the work-holding tables e, e, the bolts securing them passing into vertical T-grooves in d, so that e may be adjusted at such height upon d as may be found necessary to bring the work within proper range of the cutting tool. The work tables e, e are raised or lowered upon d by means of a vertical screw, which is operated by the handle h, this part of the mechanism accomplishing the same end as the elevating mechanism shown in [Fig. 1496]. The swivel head j is here provided at its top with a segment of a worm-wheel which may be actuated to swivel that head by the worm g.

The swivel head may thus be operated upon its pivot, causing the tool point to describe an arc of a circle of which the pivot is the centre. To steady the swivel head when thus actuated, there is behind the worm segment a V-slide that is an arc, whose centre is also the centre of the pivot.

The tool-carrying slide a is operated as follows: The driving pulley p rotates a shaft lying horizontal at the back of the machine. Along this shaft there is cut a featherway or spline driving a pinion which operates a link mechanism such as described with reference to [Fig. 1550].

The means of adjusting the distance the head of a shall stand out from b, are similar to that described for [Fig. 1496], a bolt passing through a, and in both cases attaching to a connecting rod or bar.

At k is a cone mandrel such as has been described with reference to lathe work upon which is chucked a cross-head c. By means of suitable mechanism, this mandrel is rotated to feed the circular circumference of the cross-head jaws to the cut, the slider b remaining in a fixed position upon the bed m.

To support the outer end of the cone mandrel a beam l is bolted to the two tables e, e. On l is a slideway for the piece p. At s is a lug upon e through which threads a screw r, which adjusts the height of the piece p, while q is a bolt for securing p in its adjusted position. This cone mandrel and support is merely an attachment to be put on the machine as occasion may require.

VOL. I.SHAPING MACHINES AND TABLE‑SWIVELING DEVICES.PLATE XVI.
Fig. 1536.Fig. 1537.
Fig. 1538.Fig. 1539.

[Fig. 1536] represents a shaping machine by the Pratt and Whitney Company. In this machine a single sliding head is used and the work remains stationary as in the case of the machine shown in [Fig. 1535]. The vice is here mounted on a slide which enables the work to be finely adjusted beneath the sliding bar independently of that bar, which is provided with a Whitworth quick-return motion.

As the tool-carrying slide of a shaping machine leaves its guideways during each stroke, the tool is less rigidly guided as the length of slide stroke is increased, and on this account its use is limited to work that does not require a greater tool stroke than about 18 inches, and in small machines not to exceed 12 inches. The capacity of the machine, however, is obviously greatest when the length of the work is parallel to the line of motion of the feed traverse. Work whose dimension is within the limit of capacity of the shaper can, however, be more expeditiously shaped than planed because the speed of the cutting tool can be varied to suit the nature of the work, by reason of the machine having a cone pulley, whereas in a planing machine the cutting speed of the tool is the same for all sizes of work, and all kinds of metal. In shaping machines such as shown in [Fig. 1537], or in similar machines in which the work table is capable of being traversed instead of the head, the efficiency of the work-holding table and of the chucking devices may be greatly increased by constructing the table so that it will swivel, as in [Fig. 1538], which may be done by means of the employment of Thomas’s swivelling device in [Fig. 1530]. By this means the ends of the work may be operated upon without removing it from the chuck. Or the work may be shaped taper at one part and parallel at another without unchucking it.