GB350891A - Improvements in cam grinding machine - Google Patents

Abstract

350,891. Grinding. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Norton Co. ; New Bond Street, Worcester, Massachusetts, U.S.A.) Feb. 7, 1930, No. 4215. [Class 60.] Disc apparatus.-A machine for grinding cams on a cam-shaft comprises a grinding-wheel 13 movable towards and from the work 28, and a work-table 15 movable along a base 11 by a hand-wheel 16 and carrying, on trunnions 23, 24 a rocking bar 22 provided with supports 31, 32 for the cam-shaft 28. The bar also carries, in axial alignment with the work, a master cam-shaft 30 having thereon a number of cams, which, by engagement with a roller 36 supported by a bracket 38 secured to the table 15, rock the bar to give the required form to the cam being ground, the roller being moved from one master cam to the next to grind the next cam on the shaft. The master cam is pressed against the roller by means of a spring 68 acting on a rod 57 and enclosed in a cylinder 63 carried by a bracket 60, the tension of the spring being adjustable by a threaded bushing 58 ; the rod 57 is pivoted to an arm 55 projecting from the bar 22. The master cam and the cam-shaft are withdrawn respectively from the follower and the grinding- wheel for moving to the next cam by means of a piston 71 in the cylinder 68, which piston engages a collar on the rod 57, and, when depressed by fluid pressure moves the rod 57 downwards and rocks the bar 22, release of the pressure again allowing the bar to be rocked by the spring 57 for engagement of the next cam with the follower. The admission and exhaust of fluid pressure from the piston are controlled by spring-closed valves in a casing 77 having an inlet 79, an outlet 87 to the piston and an exhaust outlet, the valves being actuated in timed relation to the movement of the work-table by a lever 100 pivoted at 101 and rocked by the contact of a roller 98 on the lever with dogs 96 on a bar 94 which moves with the work-table, the dogs being spaced to correspond with the spacing of the cams on the shaft; the dogs may be adjustable on the bar. When the bar 22 is rocked to remove the cams from the follower 36, this is moved to the next cam by a rack 124 and a pinion 128 driven, through gearing 130, 131, 135 by a star-wheel 137 moved by the dogs, the extent of rotation of the star-wheel being rendered equal for each movement of the table 15, since the master cams are spaced equally on the shaft 30, by a pawl 141.