One example shown in Fig. 1 is given of a multi-turning tool for bar work. This tool was designed for use on the electric motor shaft shown at A in the illustration. The work was handled in short lengths although the stock is a regular commercial product. Roughing and finishing operations were performed with the same type of tools. The work was held in collet jaws. Something like twenty varieties of shafts having different diameters and shoulder lengths were handled by these tools.

Fig. 1. Special Multi-turning Tool for Bar Work.

A Pratt & Whitney turret lathe with collet mechanism was used for this work; as this type of machine has a turret with dovetail faces, the body of the tool G was arranged to fit the dovetail and the gib 8 held it in place. The cut-off slide was planed off at the center and the hardened steel block F was secured to it. It will be noted that this block acts as a support for the tool, and the tongue assists in preventing lateral movement. The cast-iron block Q is fastened to the body of the tool and it is dovetailed at U to receive the tool-slide P. This is of steel and it is T-slotted so that standard toolposts 0 can be used. It will be seen that the tools C, D, and E are held in such a way that they can be adjusted readily both for different diameters and for shoulders of varying lengths. The slide is screw controlled and is operated by the handle T. A positive adjustable stop is provided by the check-nuts V. The back-rests J are of tool steel and are contained in the brackets H. The screws K, L, and N are used for binding and adjusting, while those at M pass down through slots in the body of the tool and permit adjustment of the back-rests in a longitudinal direction.

Points worthy of notice in this tool are the method of supporting the body by means of the block on the cut-off slide, the flexibility of the tool adjustments, and the ease with which any tool may be replaced if broken or used up. The tools are of standard section and therefore require no machining except cutting off and grinding.