GB539319A - Improvements in rotary cutting machines - Google Patents

Abstract

539,319. Wood cutting machine details. NIBLOCK, F. April 27. 1940. No. 7586. [Class 145 (i)] [Also in Group XXII] A rotary cutting machine of the kind described in Specification 321,306, [Class 145 (i)], having curved cutter blades mounted at an adjustable angle to the axis of a rotary spindle to vary the curvature of the profile produced on a transversely fed work piece is provided with means for varying the said curvature during operation by mounting the cutter 1 so that it may be rotated about a radial axis, during the actual progress of the cutting. The blade is secured in a carrier 2 the hub 6 of which is connected by three worm gearings 8, 11 and 14 arranged in series, to a shaft 14a carrying a star-wheel 15 which is rotated by a fixed striker at each rotation of the spindle 5. The ends of the cutter carrier are normally gripped by spring pressed cheeks 17 engaging an arcuate rib 19, the cheeks being intermittently separated to allow the cutter movement by means of polygonal members 20 actuated by another starwheel 24 and worm gearing 22. The cutter may be used for metal, wood, and other material. If the article to be machined is convex through-out a concave cutter is employed but a convex cutter may be used to shape articles which have a convex surface merging into a flat surface and then into a concave surface by gradually decreasing the cutter inclination during working. In cutting the backs of propeller blades which have a convex surface merging into a flat surface a second fixed straight-edged cutter on the opposite side of the frame may be arranged to remove the upstanding sides of the concave portion so that the result is a convexsection curve of increasing radius merging into a flat surface.