GB625816A - Improvements in or relating to profiling machines - Google Patents

Abstract

625,816. Grinding. GRUNDY, K. J. April 3, 1946, No. 10351. [Class 60] [Also in Groups XXII and XXVI] A profiling-machine comprises a grinding wheel 23, Figs. 1, 4, rotatable about a fixed axis 26, a rock-frame 27 rocking about a fixed parallel axis 28, a workholder 21 rotating about a parallel axis 25, and a profile cam 31 rotating about an axis 32 parallel to but not coaxial with the aforesaid axes and co-operating with a follower 33 to move the work to and from the cutter; in addition a member 48 of the driving means, which synchronously rotates the work and the cam is mounted at the rocking axis and is adapted to rotate in such a direction as to tend to disengage the cam and follower if an excessive braking-load is produced. In a machine for grinding turbine-blades, the rock-frame 27, having arms 29, 30, is mounted on a carriage 39 which is traversed along the bed 20 by a rack, thus - traversing the cam across the follower 33 and the work 24 past the grinding-wheel 23. A motor 38 drives the cam 31 through bevel gears 48, 50 and the work through spur gears 46. The cam is mounted on a carriage 51 which is adjusted along the arm 30 to vary the ratio of the lift at the cam to that at the work. The follower 33 is mounted on a slide 56, Fig. 6, carrying a rack 59 meshed with one of a pair of wheels 63, 64 keyed to a stub-shaft 62 on the carriage 39. The wheel 64 meshes with a rack 61 fixed to the bed 20. Thus, as the carriage 39 is traversed past the follower and the grinding-wheel, the slide 56 is moved in the opposite direction to produce a longitudinal scale effect. The gear-drives to the cam and the work-holder may be replaced by a crank and eccentric drive (see Group XXVI). Two turbine-blades may be clamped on a shaped mandrel and the convex faces machined simultaneously. A method for determining the cam-shape is described. Specification 625,881 is referred to.