GB334290A - - Google Patents

Abstract

334,290. De Vlieg, G. A. Nov. 19, 1928, [Convention date]. Milling - cutters and like tools, sharpening.-A machine for grinding rotary cutters, for example, reamers, having unequally spaced cutting elements, is provided with means whereby the work may be indexed automatically through unequal amounts. The machine consists of a base 12 on which is mounted a work table 15 carrying the cutter 10 mounted on an arbor 20 between centres 18, 19 in a headstock 16 and a tailstock 17 respectively, the table being reciprocated by drive mechanism 42 and the cutter being rotated in timed relation to the reciprocation through a universally jointed shaft 40 driven by the mechanism 42 and driving, through gearing 37, a shaft 35. The headstock 16 is adjustable, along the shaft 35 on the table and has a housing 21, carrying, on a fixed sleeve 26, a gear 27 driven by a pinion 34 on the shaft 35 and having a hub portion 28 and a flange portion 29; the hub is engaged by a spring-pressed brake shoe 30 to prevent back-lash. The arbor 20 is driven by a sleeve 43 rotatable on the centre 18 and retained in position by a spring-pressed detent 47 engaging a groove in the sleeve, and adjustably secured to a flange 48 on the sleeve is a ring 49 having a lateral arm 54, which carries a block 56. The block engages an arm 58 projecting from a ring 57 rotatable on the sleeve 43, the arm being held up to the block by a spring 59, and the arm 58 carries a cam roller 60. In the operation of the machine, the work is rotated and, on the forward stroke of the table, is carried with an edge of the cutter in contact with a grinding-wheel 14 mounted in a standard 13, thereby grinding the spiral edge of the cutter, and during the return stroke, another blade 11 is brought approximately to grinding position. In order to index the work accurately to account for the unequal spacing of the blades, the roller 60 is engaged by a cam-member 61 having spaced faces a - - d and rotatably mounted on a stud 62 secured to the flange 29, the member being rotated by the engagement of ratchet-teeth 65 thereon during rotation of the gear 27 and the flange 29 with adjustable pins 70 carried by a ring 66 adjustably secured to the housing 21; the faces a - - d of the member 61 are of the radii requisite to give the additional amount of rotation to the work relatively to the gear 27.