GB634156A - Improvements in and relating to grinding machines - Google Patents

Abstract

634,156. Internal grinding machines. AKTIEBOLAGET LINHAM. April 4, 1946, No. 10432. Convention date, March 13, 1944. [Class 60] A method of grinding the inner surface of hollow work-pieces, by means of two coaxiallymounted rotating grinding tools operating on a work-piece to which is imparted a rotary and an axially reciprocating motion, consists in adjusting the grinding tools in an axial direction relative to each other and to the work-piece in such a manner that said grinding tools are located at a distance from each other which is less than the length of the inner surface of the work-piece, and reciprocating the work-piece over a distance such that during the grinding operation both grinding tools remain constantly in contact with the surface to be ground. Grinding spindles 1, 2, Fig. 1, carrying rollers 3, 4 are mounted in cylindrical housings 5, 6 axially displaceable in guide bearings in brackets 7, 8 carried by a plate 9 'movable transversely to the axis of the grinding spindles. The latter are rotated by compressed air turbines 10, 11 supplied through flexible pipes 12, 13., The housings 5, 6 are moved axially by bell-crank levers 14, 15 ; for accurate positioning of the grinding rollers when moved to their operative positions, the housings carry stop screws 20, 21. When the rollers have been moved into their operative positions, each housing is secured by a pair of clamps, each comprising a piston-like member 23, Figs. 3, 4, and a sleeve 24 which are forced together to engage the housing 6. The two pistons 23 of the pair of clamps have tension rods 25 with nuts 28 bearing on the ends of a bar 27, and the ends of a bar 26 bear on the sleeves 24 ; a central screw 30 operated by a handle 32 forces the bars 26, 27 apart, thus simultaneously actuating both clamps and distributing the clamping pressure. The arrangement ensures 'that the coaxial alignment of the spindles is maintained. Stop pins 33 co-operating with the handles 32 limit the clamping pressure. The work is carried by a chuck rotatably mounted in the head 36 of a holder 37 which is pivotally mounted so that the chuck can be swung into and out of the working position; the chuck is driven by a belt 45 from a pulley 47 driven by a motor (not shown) through worm-wheel 48 and worm 49, the shaft of the latter extending through a slot 50 in the wall of the holder 37 and passing through a hole in a fixed ring 54 which covers the slot. A trueing diamond 53 is provided on the holder 37 opposite the chuck.