The rest or carriage r traverses along the lathe shears or bed z, carrying with it all the levers and tools, so far described.
The tailstock, or back head, carries a tool holder in the rear of the spindle, in which fits also a drill bit or other cutting tool. The method of traversing and operating the carriage r and the back head is as follows:
At the back of the bed or shears is a table, shown at t, in [Fig. 718]. Upon this table is a stand to which is pivoted the end of a lever, as is shown at 1 in figure. This lever has a joint at 2, and is connected to the tailstock spindle at a joint marked 3. It is obvious that by operating the lever laterally, joint 2 will double, and the tail spindle will be moved along the bed. If the tail spindle is not locked it will simply feed through the tailstock and the tool in the spindle will operate, but if it is locked (by the ordinary screw shown), then the handle will slide the whole tailstock and the tool in the holder at the back of the tail spindle may operate.
At 4 is an adjusting screw, which, by coming into contact with the carriage r causes it also to traverse, which it will do until it meets against a screw on the other side, marked 5, in [Fig. 718], which, standing farther out than the chuck prevents the cutting tool from meeting the chuck.
The movement of the carriage continues until the stop-gauge 6 meets the end of the work, hence the length of the work is from the cutting-off tool to the face of stop 6. The adjustment for the length of the work is made by means of screw 4, which will slide the carriage r, as soon as it meets it, independent of what distance the stop 6 may be from the work end. The tailstock carries two tool holders, similar to those on an ordinary lathe. When the cutting tools are used to cut completely over the end of the work, as in ball turning or a round ended handle, the stop 6 is not used, the tool which rounds the end acting as a stop of itself.
When bits are used they are held in the tail spindle and are made of a proper length to give the required depth of hole, or sometimes the face of the bit-holder may be used as a stop.
When the tools, cutters, and belts are all properly adjusted in position to cut to the required respective diameters or lengths the operator has simply to place a stick of wood in the lathe and operate the respective handles or levers in their proper consecutive order, and the work will be finished and cut off, the operation being repeated until the stick is used up, when a new one may be inserted, and so on.
Fig. 721.