A very complete turret lathe for working brass and other similar metals is built by the Dreses Machine Tool Company. It is shown in Fig. 302, and is known as a 15-inch friction back geared brass turret lathe, and is provided with a special chuck, cutting-off slide and a slide-rest.
The bed is of the box pattern with a dovetail top, which provides the best means for keeping alignment and for quick and firm gripping of the turret and cut-off rest. It is supported on the three-point principle to avoid springing and getting out of alignment through careless setting up or settling of floors and foundations. The top is provided with holes for the oil and chips to drop through.
The head-stock on the smaller machines is cast in one piece with the bed. In this machine it is attached to the bed by gibs and bolts. The housings are provided for either phosphor bronze or babbitt metal bearings.
FIG. 302- 15-inch Friction Back Geared Brass Turret Lathe, with Special Chuck, Cutting-off Slide and Slide-Rest, built by the Dreses Machine Tool Company.
The friction clutch back gear is of a new design, very simple in operation and positive in action. The wear is taken up by a screw driver from the outside, without even removing the cover.
The spindle is of special hammered crucible steel. The bearings are ground and run in phosphor bronze boxes with special means for oiling and taking up the wear.
The turret revolves automatically on a ground steel stem with special device for taking up the wear. It is provided with a set-over device. The top slide can be operated either by the crank and screw shown at the rear end, or by the capstan levers in the usual manner. One of the capstan handles is provided with a short handle at right angles with it for convenience in quick operations.
The entire capstan wheel may be removed and a crank substituted when quick operations are constantly required.
The longitudinal and cross-feed stop screws are located in easily accessible places. The base slide is clamped to the bed by a single handle and the operation of clamping is by a single motion.
The turret locking bolt withdraws by the return stroke of the top slide, so that the operator needs only to revolve the turret. This is equally effective as a full automatic turret, but less costly and complicated.
The index ring and key are of hardened steel and ground. The square locking bolt is provided with an adjustable taper gib, and a coil spring for actuating it.
The cutting-off slide is extra heavy and is provided with an independent stop for both front and rear tools. It has both a screw and crank wheel feed and a lever feed, either of which may be used as occasion may require.
The slide-rest is of much better design and construction than is common in similar work and is a very useful addition to the lathe, increasing its capacity in handling work of complicated nature, as by its use another series of cuts may be made without removing the work from the chuck.
The special chuck is so arranged that the work may be gripped or released while the machine is running, thus avoiding the necessity of stopping to feed the bar in every time a piece of work is cut from the bar.
The feed is a positive geared device that should do the work well and efficiently.
Taken altogether the lathe is well designed and has been provided with many very useful devices that no doubt prove convenient and effective in practical work. The special forming slide located next to the turret may, of course, be located at any point in relation to the usual cutting-off slide or the slide-rest that may be desired in order to properly perform the work in hand. Either of these adjuncts may be removed when not required for the piece to be machined, or all may be used upon a long or complicated job when needed.
A combination turret lathe built by the R. K. Le Blond Machine Tool Company is shown in Fig. 303. The head-stock and its appendages are the same as those shown in Fig. 300, and the bed and cabinets supporting it are the same. The turret.and carriage arrangements, however, are quite different and adapted to a much larger range of work.
The carriage is fitted with a turret tool-post which will carry four tools under the massive top plate shown, and which are securely fastened by the set-screws through it, thus materially increasing its capacity for different cuts on the same piece of work. A binding lever on its top secures the tool clamp in any desired position.
Fig. 303.- Combination Turret Lathe, built by the R. K. Le Blond Machine Tool Company.
The turret, is very heavy and well supported by the turret slide, upon which it is pivoted, and a long base slide or saddle. It is run forward and back by a capstan or pilot wheel with long levers giving ample hand power.
The turret can be connected with the carriage so as to be used for thread cutting and for tapping, as it thus connects positively with the lead screw by way of the apron. This feature is valuable in many respects.
In addition to the above convenience it has its own automatic feed, which has an unusually long run. As the turret has six large flat faces, each tapped with four holes in addition to the central hole for holding tools, it is well adapted for carrying large box tools, facing tools, or farming tools for special work.
The turret has the usual stops for regulating the length of the cuts, and a heavy binding nut lever for holding it firmly in any desired position.