574,335. Grinding. STUCKEMAN, H. C., FIELD, M., and CUSHING, C. G., [trading as DELTA MANUFACTURING CO.]. Dec. 21, 1943, No. 21419. Convention date, Dec. 1, 1942. [Class 60] A grinding-machine comprises a base A, a traversing table B, a work-supporting table C, a column D, a slide member E movable on the column and a grinding-wheel housing F ; by the provision of centres on the table C, the machine may be used for grinding tools or cutters. The base A is carried by legs 22 and has on its top wall 23 longitudinal lands 27, 28 and an annular land 29 having a bore 31. The land 27 has therein a guideway 32 and in the top wall 23 is a slot 33 with a notch 34. The lands 27, 28 form slides 36 to support the table B for movement to and from the land 29, and the table is guided by the vertical wall 37 of guideway 32 against which is pressed, by a gib 39 and studs, a guide bar 43 secured to a land 42 on the table B ; another land 42 on the table B rests on land 28, and aprons 48 on the table B cover and protect the slideways. The table B is moved by a screw 49 journalled in a bearing 51 in an aperture 35 in the front wall of the base A, and operated by a hand wheel 61, a micrometer sleeve 58 co-operating with a pointer 54 being provided, and the screw engages a nut 64 attached to the table and passing through the slot 33 to lie, with the screw, to one side of the slot, whereby foreign matter cannot fall onto the screw. The upper surface of the body 41 of the table B has projecting legs 68, the upper surfaces 69 of which provide slides perpendicular to the slides 36 and adjacent one leg is a guideway 75 with a vertical wall 76 serving to guide the table C. An ear 81 is formed on the body 41 of the table B to receive a stop 82 in which is adjustable a screw 85 for limiting the movement of the table. In the table B is journalled a shaft 94 operated by a hand wheel 97 and carrying a pinion 95, which lies in an opening 92 in the table and the guideway 75. The work table C has a body portion 101 with a work-supporting face 102, and'on its underside a series of bosses 107 provided with notches 108 to receive a rack bar 110, which is pressed against the guide wall 76 by a gib 77 moved by screws 78; the rack bar engages pinion 95, and is provided with a longitudinal groove 113 engaged by washers 118 so as to prevent lifting of the table C. The slides are lubricated by oilers 73, ducts 71 and wicks 72. On the front wall of table C. two holders 123 are mounted carrying a stop rod 124, on which are adjustably secured two blocks 126 co-operating with the screw 85 to stop the table in any desired position; the face 102 of the table has therein a T-slot 103, or may carry a vice or a magnetic chuck. The column D has a flange 130 near its lower end 131, which is disposed in the bore 31 in base A with the flange resting on the machined surface of land 29 and has, along one side, a groove 136 in which is secured a guide bar 137 ; the column may be rotated on its axis to a desired angular setting, as indicated by a scale 232 and a pointer, and is locked in position by a rod 138 engaging at its lower end a plate 139 resting on a boss 30 on the base A, and at its upper end carrying a nut 142 and cap 143. The cap 143 has an offset ear 146 which receives a screw 147, rotatable by means of a hand wheel 152, the screw being axially fixed and the weight being taken by a fibre washer 158. On the column D is mounted the slide member E ; this comprises a body 161 split at 162 and having a guideway to receive the bar 137 and carrying a gib pressed by screws to ensure proper contact of the bar and the guideway. The slide member is moved on the column by the screw 147 which engages a threaded sleeve mounted in the slide ; a close fit between the slide and the column is assured by drawing the split 162 together by means of a stud 179 and nut 178 and the slide may be locked in adjusted position by a stud and a threaded sleeve operated by a handle 189. The frame F is pivotally mounted on the slide E by means of pivot screws 195 carried by the side bars 196 of the frame and engaging recesses 194 in bosses 193 on the body 161; the side bars at one end merge into a motor base 198 and at the other end into a spindle housing 199. The base 198 carries an electric motor 201 in a housing which extends along one side of the column D, covering the side bar 196 and shaped to the outline of the housing 199. The housing 199 has thereon a boss 209 to receive a hardened screw cap 211, which co-operates with a micrometer screw 212 carried by an arm 214 of the body 161 and serving for fine adjustment of the vertical position of a grinding-wheel 230 carried by a spindle 229 mounted in the housing 199 ; angular adjustment of the wheel is effected by rotation of the column D in the base A. The mounting for the spindle 229 comprises two seats 235, 236 machined in the housing 199, the spindle having a reduced end 239 carrying a pulley 245 and also a ball bearing 242 slidable axially in the seat 235. The seat 236 receives a tapered bearing assembly comprising a tapered sleeve 252 secured to the spindle, and a co-operating tapered sleeve 256 fitting the seat held with its end abutting a shoulder 238 in the housing 199 by a 'screw 257 ; a thrust washer 259 has its flat face engaging the end of the sleeve 252 and is held in position by a split nut 261 screwed into the flange 262 of the sleeve 256, the nut having a conical bore engaging the rounded face of the washer 259, and being locked by a screw 263. The bearing is lubricated by a ring 271 in a notch 269 in the sleeve 256, the ring dipping into a reservoir 267 ; an oil return duct 272 is provided in the sleeve 256, and radial grooves in the thrust washer 259 carry the lubricant to the end of the sleeve 252. The grinding-wheel 230 is mounted on an adapter which is detachably secured on the tapered end 275 of the spindle 229 by a nut 287 screwed on a setscrew 286 in the end of the spindle ; the adapter comprises a bush 276 with a flange 278 against which the wheel is clamped by a flange member 283 and a nut 285. A guard for the belt 246, which drives the grinding- wheel, is provided, the guard 291 comprising a dished casting 292 with apertures 293-295 therein to receive the motor shaft 248, screw 195 and the end of the spindle 229, the casting being secured to a post 296 on the frame F and to the spindle housing 199, a slot allowing of adjustment of the casting ; a cover 303 with a flange 305 overlapping the wall 306 of casting 292 is secured in place by studs 302 and nuts 307. A guard also is provided for the grinding-wheel, comprising a part 309 secured by screws to the end of housing 199, one screw passing through an arcuate slot 317 in the member 309 and carrying a locking nut 318. The grinding-wheel is dressed by a tool 358 mounted in an inclined opening 357 in a block 352 having flanges 354, 355 each with a slot 356 therein for a bolt 361, whereby the block is secured to surface 102 of table C, the tool being traversed over the wheel by operation of the hand wheel 61 ; a cup-wheel also may be dressed by securing the flange 355 to the surface 102 and operation of the hand wheel 152. A light bracket is provided on the arm 214 carrying a light 374 having a shade 376.