GB190409869A - Improvements in and relating to Machine Tools. - Google Patents

Abstract

9869. Franz, B. April 29. Milling; boring and drilling; lathes; screwing; feed-motions.-In machine tools, the feed or resetting of the work or tool is effected, during the return movement, directly by means of the mechanism producing the return, rendering a special dividing-device unnecessary. The tool is removed from and returned to the cut automatically and suddenly. Fig. 1 illustrates the invention as applied to a machine for milling, for example, the spiral grooves in twist drills. The milling-cutter 3 is mounted in an angularly - adjustable head mounted on a slide 6. The work is held in a spindle 5 rotated by worm, spur, and bevel gearing from a shaft 12 slidable through the boss of a clutch and wheel 20, 11, geared to the shaft 8 which produces the forward motion of the spindle carriage 4. Tappets 25, or a striking ledge of suitable length, engage a spring-controlled lever 23 on the return of the carriage, and temporarily unclutch the shaft 12 to produce the required amount of angular feed. A spur-wheel 31 rotatably secured to the frame and driven from the shaft 8 has a screwed boss receiving a sleeve 32 feathered to a non-rotatable rod 33 connected at one end to a rack plunger 39 and at the other to a detent plunger 36. During the traverse of the carriage 4 in either direction, one or other of the springs 34, 35 is compressed and when, by a tappet or other arrangement, a detent is removed from one of the holes in the plunger 36, the spring is relased, and the rack plunger rotates the screw 7 through the intermediate spur gearing, thus removing the tool 3 from the work or returning it as the case may be. The detention and liberation of the rod 33 may be effected in any other way, such as electrically. This method of return may be applied for cutting screws on ordinary universal machines. The springs may be replaced by other traction or pressure means such as compressed air, water under pressure, a raised weight, or the like. The invention may be applied to effect the division in wheel-cutting machines, the return and reversal of a lathe headstock or capstan, or the quick return of a drill spindle or boring-head.