632,567. Grinding crank-shafts. NORTON CO. Dec. 19, 1944, No. 25494. Convention date, March 2. [Class 60] [Also in Group XXII] A crank-shaft grinding machine of the kind having a rotatable face plate and a chuck, for adjustably supporting a crank-shaft to be ground, said chuck being adjustably mounted on a slideway supported on said face plate, is characterised in that said slideway is mounted on said face plate for adjustment thereon in a direction normal to the direction of adjustment of said chuck so that by adjustment of said slideway on said face plate it is ensured that the path of adjustment of the axis of the crank-shaft supported by said chuck passes through the axis of rotation of said face plate. Preferably the slideway is provided on a chuck plate which is removably mounted on the face plate. General.-The machine comprises a base 20, Fig. 1, supporting a work-supporting table 21 longitudinally movable by hand wheel 25 and also supporting a grinding wheel slide 31 transversely movable by hand wheel 34; the slide 31 carries a grinding wheel 35 driven by an electric motor through multiple V-belts. The work table 21 carries a headstock 41 and footstock 42 for rotatably supporting a crank-shaft 43. Headstock.-A face plate 45, Fig. 5, is attached to a multiple V- groove pulley 46 journalled by bearings 47, 48 on a non-rotatable headstock spindle 49. The face plate is rotated by an electric motor 50 through belts 52, 58 and 65, the idler pulleys being mounted eccentrically for belt tensioning. A circular plate 80, Figs. 2, 3 and 5, is located on the face plate 45 by a pair of diametrically arranged keys 81, 82 fitted in a diametrically arranged keyway 83. The plate 80 is accurately located and centred relative to the face plate 45, after which it is located by dowel pins and clamped in position by screws 84, 85. The plate 80 has fixedly mounted thereon a diametrically arranged dovetail slideway 88 arranged at right angles to the keys 81, 82. A pot chuck slide 89 has a dovetailed slideway mating with the slideway 88. An adjusting screw 105 carried by the part 88 engages a threaded part of the slide 89 ; a collar 108 pinned to the screw is preferably graduated. After adjustment of the slide 89, additional slideways and guideways 90, 91 engaging slide surfaces 92, 93 on the outer edges of slide 89 are clamped rigidly in position to lock the slide 89. The pot chuck slide 89 has mounted thereon worksupporting plates 94, 95 forming a V-support; a clamping strap 97 is pivotally mounted at one end on a stud 98, the other end of the strap 97 having a U-shaped notch 99 engaged by a clamping screw 100, pivotally supported on a stud 101, and provided with a nut 102. The pivot stud 98 is supported on the upper end of a screw 103, whereby the pivot stud 98 can be adjusted to vary the capacity of the chuck. For larger work the strap 97 is inverted. Scales calibrated to read " Throw and " Bearing Diameter " are provided to facilitate adjustment. To locate the chuck in a vertical or loading position, a spring-pressed plunger 118 is provided which engages a notch 119 in the chuck plate 80. An adjustable counterbalance weight 125 is provided. In a modification, the plate 80 is pivotally mounted on the face plate 45 and adjustment is effected by swinging the plate 80 about the pivot. Footstock.-The footstock 42 has a slidably mounted sleeve 68, Fig. 22, in which is mounted by anti-friction bearings 69, 70 a rotatable spindle 71 with an integral flange 72 which supports an adjustably mounted pot chuck for supporting the right-hand end of the crankshaft ; the position of the sleeve 68 is adjusted by a hand wheel 73, and a clamping screw 74 is provided. The pot chuck is constructed and mounted similarly to that on the headstock. In order to locate the chuck in a vertical or loading position, a spring-pressed detent engages a notch in a block secured to the pot chuck plate; for angular relative adjustment of the two chucks, the block is adjustably secured to the pot chuck plate. Steady rests.-A steady-rest frame 200, Fig. 13, removably clamped to the table 21 supports a horizontally adjustable slide 201 carrying a steady-rest shoe 202 which contacts the crankpin 117; the slide 201 is adjusted by a screw 203 with a hand wheel 205. A second shoe 206 is carried by a bell-crank lever 207, 209 pivoted at 208 and adjusted by a screw 210 having a knob 212. The horizontally movable steadyrest shoe 202, which is provided with a tip 215 of hard cemented' carbide, is utilized to locate the crank-pin to be ground in a predetermined grinding position and for this purpose a scale 216, calibrated in " inches diameter " of the crank-pin, is provided on the frame 200 and co-operates with a pointer 217 mounted on the slide 201. Checking concentricity of crank-pin; work size gauging.-A lever 231 pivoted at 232 on the frame 200 has a work-engaging tip 233 and an extension 234 provided with a rounded end 235 received in a slot in a rod 224 slidably mounted in a cylindrical slide member 221 supported by a bracket 220 on the steady-rest frame 200. The rod 224 is normally urged to the left by a compression spring 230; its righthand end bears against an actuating of a plunger 225 of a dial indicator 226 carried by the cylindrical slide 221. The cylindrical slide 221 is adjustable lengthwise in its bracket 220, being secured in adjusted position by a clamping screw 229; movement of the slide 221 towards the work is limited by an adjustable screw stop. The indicator 226 enables the operator to set up the work properly concentric and also indicates the progress of grinding.