GB578663A - Improvements in milling and grinding machines for machining arcuate surfaces - Google Patents

Abstract

578,663. Grinding arcuate surfaces. BARKER, E. Feb. 15, 1944, No. 2767. [Class 60] [Also in Group XXII] A machine for milling or grinding arcuate surfaces comprises a cutter, a pivoted table for carrying the work, variable speed means for turning the table in, one direction, so that the work is fed rapidly up to the cutter, at a slower speed past the cutter and then at a rapid reverse speed back to its initial position, a reciprocable timing bar with adjustable stops thereon operated from the mechanism for moving the table and means controlled by the stops for regulating the speed and direction of movement of the table. The frame of the machine comprises a bed 2, stanchions 3 and 4 and an overarm 5. The work table 6 is pivoted at 7 and may be oscillated by means of a hydraulic cylinder 12, rack-11 and a pinion 9 meshing with teeth 8 formed on the table. A reciprocating timing bar 15 carrying adjustable stops. 16 is reciprocated from the rack 11 through gearing. A work holder 24 for the work 23 is adjustably secured to the table'as by a dovetail connection or by T-slots and a scale is provided to facilitate setting-up. On one side of the overarm 5 is mounted a slide 28 with a manually-operable screw 51, the lower part of the slide carrying a vertical milling cutter 25 driven from a spliried shaft 29. The other side of the overarm supports a slide 30 with a manually-operable screw 52. This slide carries two shafts 53, 54 driven by worms 34, 35 from a splined shaft 39, said shafts having horizontal milling cutters 26, 27 at one side of the slide and similar cutters 26a, 27a at the other side. Shaft 54 with cutters 27, 27a is mounted in a slide 31 vertically adjustable on the slide 30. Cutters 26, 27 are used for working on parts B, C of a convex body 23, Fig. 6, and cutters 26a, 27a for parts E and F of a concave body 23a, Fig. 7, the faces A and D being machined by the vertical cutter 25. The rate and direction . of the supply of. fluid from a tank 45 to the cylinder 12 is controlled by control mechanism 14 of known type. A manual lever 42 is actuated to begin the advance of the work. As the work reaches the cutters, stop 16 depresses control rod 41 to reduce the rate of feed and at the end of the traverse, stop 16a actuates a limit switch 46 to stop ,the motor 40 which drives the splined shafts 29, 39 and at the same time the stop 16b depresses the rod 41 to stop the feed. After a predetermined dwell, electric timing apparatus energized by the operation of the. switch 46 causes a solenoid 47 to move the control rod into the reverse position and the table is moved rapidly back past the stationary cutters until stopped through the action of stop 16c. The milling cutters may be replaced by grinding-wheels,