GB168623A - Improvements in or relating to grinding machines - Google Patents

Abstract

168,623. Wade, H., (Norton Co.). May 3, 1920. Disc apparatus. - A machine for grinding cams on a cam-shaft - comprises a swinging frame, in which the work is mounted and continuously rotated at a constant velocity ratio from a stationary source of power. A shaft 12, Figs. 1, 2 and 3, on which are cam-blanks to be ground, is carried in a frame 1 pivotally mounted on supports 8, 10 on a table 3, which is slidable on a base 4. The shaft 12 is rotated by a lug 17 and a dog 18 from a spindle 20 carrying removable mastercams 21. Spiral-springs 42 with adjustable tensioning-means, or a weight and pulley, tend to swing the frame 1 so that the work 12 approaches a grinding-wheel 40, which is mounted on a fixed axis. The rotating master-cam 21 contacting with a revoluble shoe 22 on a fixed spindle 23 oscillates the frame 1 and causes the cam-blank opposite the grinder 40 to be ground to a corresponding contour. The shaft 20 receives continuous rotation from a shaft 63 in stationary bearings through gears 66, 65, a telescopic shaft 57, and gears 56, 55. The shaft 57 and its gears 56, 65 are mounted in housings 58, 78 respectively journaled on the shaft 20, 63. The shaft 57 is slidably keyed to the worm-wheel 65 by balls running in keyways. Bevel gears may be substituted for the worm and worm-wheels. A drum 48 on the shaft 20 is frictionally engaged by an adjustable band-brake held against rotation by a pin 47, and thus prevents back-lash, The shoe 22 is set opposite the required master-cam 21 by rotating a hand-wheel 30 on a spindle 29 and, through bevel-wheels 27, 28, a screwed spindle 26, which engages a yoke 25 straddling the shoe 22 and slides the latter along its spindle 23. A block 33 engaging a screw-thread on the shaft 29 indicates which master-cam is being used. As the sliding table 3 is moved to bring a fresh blank opposite the grinder 40, the spindle 26 may be rotated automatically through gears 113, 114, Fig. 11, by a pinion 111 engaging a rack 110, which is adjustably secured to the base 4 so as to allow of various sized pinions 111 being used according to the distance between the cam-blanks. A lost motion connection between the pinion 111 and its shaft 112 allows of the work being traversed across the grinder without shifting the shoe 22 from the corresponding master-cam, A handlever 100 connected by a rod 101 to a pin-lever 102 serves to swing the frame 1 away from the grinder when a new cam-shaft is inserted. The master-cams are made by reversing the arrangement of the grinder and the shoe, but keeping to the same radial dimensions of the rotating parts contacting with the cams and master-cams.