GB517291A - Improvements in grinding, buffing, polishing, boring, milling and like machines - Google Patents

Abstract

517,291. Grinding, polishing, boring, milling, &c. 'GRIEVING, R. July 18, 1938, No. 21320. Convention date, April 28. [Class 60] [Also in Groups XXII and XXIV] In a grinding, polishing, boring, milling or other machine the tool is driven through continuously variable speed mechanism, means also being provided for the use of two or more speed ranges, the speed being continuously variable throughout each range.. The tool spindle 16 is mounted in a casing 1 which may be secured to a lathe &c. and is secured by bolts at 15 to a gear casing on which is mounted an electric motor 3. The motor drives, through a belt 4, a shaft 18, and the shaft 18 drives through continuously variable gearing, a shaft 24, which drives the spindle 16 by either of the belt drives 6, 7 according to the speed range required. The variable geardng, as described, comprises a cone 5 on each of the shafts 18, 24, and a slidable cone 5 mounted on each of the shafts and movable in the same direction by blocks 27, 27<1> so that as the upper cones 5, 5' move together, the lower cones move apart and vice versa, whereby a driving ring 28 engaging the cones drives the shaft 24 at variable speeds. The blocks are linked together, and one of them, 27, is moved by a rack thereon engaged by pinion 13 driven through gearing 12, 29 by a handwheel 9. The speed is indicated by a scale 10 and a pointer 31 which is moved by a follower 11 on a pivoted arm 31, the follower engaging a spiral slot formed on the rear of the handwheel 9. The gear is locked at any set position-by a pawl 8 which engages the teeth of the wheel 12. The driving belts can be arranged to provide three or more speeds and other types of continuously variable drive may be employed instead of the cones and ring 28. Specifications 373,859, [Group XXIV], and 498,695 are referred to.