This is virtually a planer for planing small work. It is not designed like the planer, however, and the essential difference is that the work table remains stationary, except for the feeding motion, and the tool is moved back and forth over the work. The shaper is a quicker-moving machine than the planer. It cuts in but one direction of its stroke.
Fig. 195 shows a type of small shaper much used. A feature of all shapers is the quick-return motion, as mentioned for the planer.
The Whitworth quick-return motion is much used in shaper mechanism.
Work is clamped in the vise V which is bolted to the table T. The table is carried by the cross-rail R which may be raised or lowered by hand mechanism along its slide S at the front of the column of the machine. An adjustable support B assists to hold the table rigidly.
Fig. 196. - Plain Milling Machine.
The tool, which is not unlike a lathe tool in form, is clamped in the tool post P which is carried by an apron on the head H. This head is carried by the ram M which is made to slide back and forth in its guides on the top of the machine. The vertical position of the tool is adjusted by the screw handle C. The length of travel of the ram is adjusted to suit the work by a hand crank on the spindle D, and the range of its travel, i. e., the limits of the ends of its stroke, is governed by the crank above the ram.
The machine is driven by means of a belt on one of the cone wheels. As the ram moves back and forth, the table is gradually fed at the end of each stroke along the cross rail by the mechanism Kln until the work is carried entirely across the range of travel of the tool. The tool is then slightly lowered by the screw handle for a new cut, and the table is fed back in the opposite direction.
The machine is so built that the ram and table move horizontally, one at right angles to the other, and the cross rail raises or lowers vertically.
For holding small flat work of steel or iron quickly and readily, a small electro-magnetic chuck has been designed for use with the shaper. It is bolted to the table or clamped in the vise and is supplied with direct current for the magnets.