The distinctive feature of the original Flat Turret Lathe was the fiat, plate-shaped tool holder from which the lathe took its name. The original work-holding head stock possessed many distinctive features, such as the automatic chuck and roller feed, but it contained the now nearly obsolete cone pulley drive and back gear scheme. In the present machine we have combined an ideal scheme of speed regulation with many other desirable features.
The cross-feeding feature of the head grew out of our desire to get the best form of self-contained speed variator. After trying several combinations and positions, we found it best to arrange all the shafting and gearing in a horizontal plane, so that the lower half of these running parts could be submerged in oil to insure perfect lubrication. This determined the adoption of a shallow, pan-shaped frame for the head stock, into which were placed all the clutches and
Main Spindle with Automatic Chuck and Roller Feed for Bar Work, and Showing Main Bearing bearings, including main spindle bearings. The natural form of bed for holding this head stock made the way open to give the head stock a cross travel, which we had long realized was a most desirable feature.
A most fortunate combination was the result. We not only obtained a most compact and symmetrical machine, but in one machine we succeeded in getting practically all of the features made desirable by present-day conditions.
The sliding head stock is securely gibbed to guideways running across the machine, thus giving the work-carrying spindle a cross feed relative to the turret, or, in other words, providing a cross feed for each tool.
The value of this feature is not only for chuck work, but for many other kinds of work.
The single drive receives power at a constant speed and in one direction, and all of the changes for variation and direction of speed are obtained by clutches and gears between the power-receiving shaft and the spindle.
Since the pulley receiving the power is driven at a constant speed, it may be belted to countershaft above or to a constant-speed electric motor on the floor at the head of the machine. The motor requires only our compensating base to maintain even tension of the belt. No controller is nec-
Cross-feeding Head, showing the Rotary Stop Holder Containing Ten Stops essary, only a starting box, and since we do not vary the motor speed, it is not necessary to provide a motor four times the nominal size to compensate for loss of power due to reduced speed. Since we use belt connection, any kind of motor may be used, thus avoiding the delay incident to getting a given type of motor.
The new high-speed steels tax the running-bearings of a machine to their limit, and to meet this we have used bronze bearings for the driving shafts, and all of these bearings get a continual shower of oil when running, for they are enclosed in the chamber formed by the shallow, pan-shaped head stock and its lid.
The cross-sliding head is provided with ten stops carried in a revolving holder, which is turned at will by the operator.
Sliding Head Stock with and without Cover. Pulley shaft is driven at constant speed and in one direction only. All changes of speed effected by two lower levers at right-hand side, the reversing by lever at left-hand side, to which shipper bar is attached. The upper lever at right actuates the automatic chuck and roller feed