A type of this machine is shown in Fig. 202. This is known as the crank-driven type to distinguish it from the heavier gear-driven type.

The slotting-machine movements resemble very much those of the shaper. The machine is employed particularly for slotting key ways in the hubs of wheels, and is found useful for much other slotting of various kinds. Work is clamped on the horizontal table A which may be adjusted by giving it (1) a circular motion; (2) by moving it horizontally along the slides B, or (3) by moving it horizontally along the saddle C at right angles to the motion of (2). These motions may be imparted to the table slowly by the feed mechanism D, which changes the position of the work gradually during the course of the operation of slotting. 21

Fig. 202.   Slotting Machine.

Fig. 202. - Slotting Machine.

The cutting tool moves up and down in a fixed vertical line perpendicular to the face of the table. It is clamped firmly in the yokes G at the end of the ram H which works in the guides KK. The ram is operated by the connecting rod L, the upper end of which swings on the bolt M, and the lower end of which is held on a crank pin which may be readily adjusted along the dovetail slot in the disc N to give the tool a greater or less length of movement. The weight of the ram is counterbalanced by the weighted lever P. The disc N is on the end of the main spindle which is driven with a quick return motion by the large wheel R geared to the driving cones S.

Fig. 203.   Tools for the Slotting Machine.

Fig. 203. - Tools for the Slotting Machine.

The path along which the point of the tool moves may be raised or lowered by raising or lowering the ram in reference to the nut at M.