GB488996A - Improvements relating to the manufacture of metal cutting tools - Google Patents

Abstract

488,996. Turning. ALEXANDER, J. W. Jan. 15, 1937, No. 1234. [Class 83 (iii)] Means for facilitating the turning in lathes of rotary " form " tools having a configuration of complex shape comprise the combination of a slide adapted to carry the cutting tool and movable in longitudinal and transverse directions, and optical means for projecting a silhouette or image of a portion of the profile of the work-piece on to a screen carrying an enlarged drawing of the desired profile and means for causing the position on the screen of the projected image to vary in a manner correlated with the movements of the cutting tool. A saddle c supports a pair of cross-slides h, o, which carry the tool j and optical means u, s, t, x, y, respectively, and are connected by a linkage q, r so that movement of the toolslide produces equal movement of the other slide in the opposite direction. A backing plate 16 adjustably supports the screen p which carries the drawing of an enlarged view of, say, one half of a " form " tool to be produced. The optical means project an image on to the screen of the portion of the work adjacent the tool and the latter is manipulated to turn the work and thus bring the image into agreement with the drawing. The plate 16 carries rollers 17 which run on rails 18, and longitudinal movement is imparted to the plate from the saddle through a rod 5, fixed to the saddle, an endless chain 7, and bevel gears 11 which rotate a bevel screw 12 engaged by a half-nut 13 connected to the plate. Raising and lowering movements are imparted to the rails carrying the plate 16 through the screw-andnut gear 22, 21, driven by gearing from the feed screw k for the cross-slide. The screws 22 are inclined and the gearing arranged so that the horizontal distance between the screen p and the prism y remains constant. Specification 478,755 is referred to.