DE2253447

1380118 Milling slots beds and frames; making rotors GLEASON WORKS 12 Oct 1972 [1 Nov 1971 22 May 1972] 47151/72 Headings B3K B3B and B3A Accurate slots 32, Fig. 3, are cut in a previously drilled workpiece 30 by a milling machine comprising a frame 10, Fig. 1, a spindle housing 20, a rotatable and axially movable tool spindle 22, a cutter head 38 secured to the spindle, and a plurality of cutter holders 44, Fig. 4, independently axially movable in the head from a non- cutting position to a cutting position, and a cam means 56, 68, for selectively moving each holder to the different positions at predetermined angular positions of the spindle. Workpiece 30 is carried on a table 28 which can be indexed so as to bring the workpiece into position relative to the cutter head and the several blind slots 32 can be cut in turn. Each cutter holder 44, of which there may be up to thirty, is laterally adjustable by a shim 48, Fig. 5, in combination with set screws 49, and is moved axially of spindle 22 by a fluid pressure piston 22 against the action of face cam 68 having ramps 92, 94, Fig. 6 thereon, the ramps being positioned so that as the spindle 22 rotates the cutters 52 enter an access hole 35 and are retracted from a second hole 36. The workpiece may be the rotor of a rotary piston combustion engine.