Fig. 315 shows a Cleveland automatic machine, of which several variations of the same style are built. The main spindle A is driven from the system of pulleys B, the belt being controlled by the automatically operated shifter C. At D is shown the device for opening and closing by hand the chuck in the head E of the main spindle A when setting the machine. The mechanism by which the bar of stock is forced forward through the chuck, is at F.

Fig. 314. Latest Type of Automatic Chucking and Turning Machine Courtesy of Potter and Johnston Machine Company, Pawtucket, Rhode Island.

The turret mechanism is at G, and consists of a cylindrical device with its axis in a horizontal position and journaled in the housings at HH, sliding in the left-hand housing in making the cut. This form of turret is exceedingly rigid. The tool-holes are bored in the end of the cylindrical portion g, and the tools secured by set screws, as shown. The turret is moved forward and back by a mechanism operated by the shaft N; and is revolved on the back stroke by suitable helical cams, a portion of which is shown at K. In setting the machine, the turret is operated by the crank M, upon whose shaft is a worm engaging the worm wheel J.

Fig. 315. Cleveland Automatic Machine Shown for Analysis.

Fig. 316. Latest Type of Cleveland Automatic Machine Courtesy of Cleveland Automatic Machine Company, Cleveland, Ohio.

The cross-slide L is arranged for two tool-posts, and is operated by a suitable mechanism in the rear. It is adapted for carrying forming tools as well as the usual cutting-off tools.

There are a number of interesting and valuable attachments furnished with these machines, among which is one for slotting screw-heads, and for slabbing or milling at a time, two sides of square or hexagonal heads by a straddle mill. There is also a third spindle speed attachment, in which the center pulley B, usually an idler, is utilized as a driver; and by the addition of a set of differential gears, the spindle speed is reduced in a ratio of three to one, giving a slow speed for threading large work. By this means the spindle speed can be as rapid as is possible for the use of high-speed steel tools, and still have a slow speed available for large tapping or threading.

Fig. 317. Universal Multiple-Spindle Automatic Screw Machine.

In case solid dies are used and the threading done with the belt on the pulley B (now a driver), the belt is thrown to one of the other pulleys, and the fast reverse speed used to run the die off the work. A magazine attachment is also made for automatically feeding castings or drop forgings down to the chuck, so as to dispense with the services of the operator on this class of work, except to see that the magazine is kept supplied with work.

In Fig. 316 is shown the latest type of Cleveland "automatic".

Universal Multiple-Spindle Automatic Screw Machine

This machine, Fig. 317, is of a type distinctively different from either of the previous examples. The operative parts are operated mostly by the usual drum cams, three of which, A, B, and C, are used. The peculiarity of the design of this machine is that the work is carried in five revolving spindles at D, while axially opposite them are five tools. The revolving spindles carry five bars of stock, upon all of which work is being done simultaneously. The results secured by this arrangement are that the work necessary for completely finishing a piece is no longer than that required for performing the longest single operation, regardless of the number of operations required on the piece.

The machine is driven by a single belt upon the pulley F, the power being transmitted by spur gearing to the center shaft G, which runs through the spindle head H, at the left of which it is connected by spur gears with the five spindles at D. There are three cross-slides J, K, and L, the tools of which act at the same time as the box tools or other tools usually carried in a turret. The cam shaft carrying the cams A, B, and C is driven by a belt from the pulley M to the two pulleys N, which, by means of differential gearing, give two speeds to the shaft; on the latter is a worm engaging the worm wheel P, thus providing for a rapid speed for indexing, and a quick advance and return of the tools. The belt is shifted automatically to the inner pulley, which drives the shaft slower for the feeding of the tools on the cut. The squared end of the cross-shaft provides for a crank which may be used to rotate the mechanism when setting the machine.

The design of the machine is very ingenious, and its output on small work should be very large in consequence of having five or more tools continuously employed during the time that in the usual type of machine there is one (or, at most, two) in active operation.