Patent GB-628146-A (GB)
Title: Improvements in or relating to traverse mechanisms for grinding machines and the like
IPC: B24B47/06
Filed: 1947-01-27
Abstract: 628,146. Grinding and polishing. FAIREST, Ltd., M., and FAIREST, M. Jan. 27, 1947, No. 2434. [Class 60] [Also in Groups XXII and XXIX] A traverse mechanism comprises a reversing-valve 70, Fig. 6, adapted to receive pressure-fluid and direct it to actuating means 49, Fig. 2, for traversing the work-support 10 of a grinding &c. machine, and pressure-responsive means 89 built into the reversing-valve structure and to which pressure fluid is directed by the reversing valve concomitantly with the direction of pressure-fluid to said actuating means during at least a traverse stroke in one direction, the means 89 being adapted to actuate the valve 70 at the end of that stroke by the build-up of pressure in the fluid consequent upon the work-support 10 reaching a stop 64 at the end of that stroke, thereby reversing the direction of traverse of the support. In a machine for grinding knife-blades, a blank 22, Fig. 1, is carried on a support of the type described in Specification 627,330, which comprises a work-holder 20 pivoted at 19 to a bracket 17 adjustably mounted on a carriage 16. The carriage 16 is movable on inclined guideways 40 formed in the support-slide 10 which moves on guideways 11, Fig. 3, carried on a base-plate 12 angularly adjustable about a pivot 34 on the machine-bed 13. The blank is moved idly past the grinding-wheel 15, to the right in Fig. 1, until, at the end of the stroke, a cam-bar 55, sliding within the slide 10, contacts an adjustable stop 62 causing a follower 61 mounted on the carriage 16 to mount a slope 59 of the cam-bar 55; the carriage is thus moved against a spring 46 to press the work against the wheel 15. The slide 10 is then stopped by the adjustable abutment 64 and dwells while the bolster is ground before being moved back at an adjustable feed rate. During the feed-stroke, the carriage 16 is held in place by friction and is supported along the length of the cambar 55. As the feed progresses, an arm 23, carrying a follower 24 running on a camplate 25, tilts the work-holder 20 to compensate for the decreased thickness along the length of the blade. The wheel 15, Figs. 1 and 4, is cup-shaped and is inclined to give a convex shape to the blade. The edge 32 is inclined at the same angle as the axis and the end 15a is formed to shape the bolster of the knife. By reversely tilting the wheel, blades may be hollow-ground. At the end of the feed-stroke, an arm 56 on the bar 55 contacts an adjustable stop 66 causing the carriage 16 to spring away from the wheel as the follower 61 snaps back into the cam-recess. The slide then continues idly until the arm 56 again contacts the stop 66. The movements are controlled hydraulically, (see Group XXIX). Movement of a hand-lever 140, Fig. 2, to the right allows pressure to enter the left hand end of a cylinder 48 to move the slide rapidly to the right. At the end of the stroke, pressure builds up behind the pressure-responsive piston 89, Fig. 6, until sufficient to move the valve 70 and the handle 140 to the neutral position. The dwell that occurs may be varied by a needle-valve to allow the bolster to be fully ground. The slide is now reversed and travels at a rate controlled by an eccentric valve 119 in the feed circuit. This valve may be by-passed by holding the lever 140 to the left thus giving a fast light polishing stroke to the blade.