GB374579A - An improved method and means for internal grinding and like operations - Google Patents

Abstract

374,579. Boring engine cylinders &c. SCOTT, J. A., 418, Rotherhithe New Road, Bermondsey, London. April 28, 1931, No. 12539. [Class 83 (iii).] Boring-heads.-In a device for the internal grinding or boring of engine cylinders, a short grinding-spindle 12 is adjustably mounted in an eccentric bearing in the grinding-bar 10 and is driven from a separate driving-shaft 24 extending axially through the grinding-bar, and for trueing up a bore prior to grinding, a cutting tool attachment 48 may be secured to the lower end of the grinding-bar. The tool 52 may be set by means of a disc 54 engaging the slotted end of the tool holder. Bearing-bushes for the driving-shaft are provided at 25, 26 and lubrication may be effected through a hole 27 above a reservoir 28 which communicates with passages to lubricate the driving-shaft and grinding-spindle. An angle-plate 31, Fig. 2, may be secured to an engine block to be rebored and is fitted with a bearing-block 34 which is normally secured to the angle-plate but may be moved vertically to permit inspection of the work. The grinding-bar is mounted in bearing-bushes in this block and is driven by a worm wheel 38 splined on the bar and driven from a shaft 47. The bar is fed thiough a feed block 43 by a lead screw 42, the latter being diiven by worm gearing 46 which may be coupled to the shaft 47. The direction of the vertical feed may be changed automatically and the radial feed of the grinding wheel may also be effected automatically by stops on the bar 41 coacting with the star wheel 19, the vertical length of the stop determining the amount of feed. The grinding-bar may be supported at both ends as shown in Fig. 5 a pair of eccentric bushes being provided as shown for supporting the grinding-spindle which is driven as above described from a shaft 24. In the case of large cylinders, the grinding-bar may be of skeleton formation and in some cases the cylinder may be moved longitudinally over the grinding-bar. In another modification, the boring-bar may be composed of two sections and the ends of the driving-spindle may be connected together by interengaging semicylindrical portions. The apparatus may be used for taper boring by feeding the tool during its passage through the work.