Patent GB-258851-A (GB)
Title: Improvements in or relating to cylindrical grinding machines
IPC: B24B5/35
Filed: 1926-09-06
Abstract: 258,851. Norton Co., (Assignees of Norton, C. H.). Sept. 28, 1925, [Convention date]. Rollers, spindles, and the like, treating; gauges.-A machine for grinding cylindrical work consists of means for feeding the work automatically to work holding and rotating mechanism, and a grinding-wheel which is fed automatically a predetermined distance to grind the work to size, and then is withdrawn to allow of discharge of the work and replacement by another piece: The machine consists of a base 10 supporting a grinding-wheel 19, carried by a transversely movable slide 13, and rotatable and axially slidable work-supporting spindles 20, 21 mounted in bearings 22, 23 and driven in synchronism by chain gearing 64, 65 and toothed gearing from a shaft 43, which is driven from a main shaft 30 through a clutch 44 and chain gearing 41; the chains 64, 65 may be tensioned by angular adjustment of brackets 70, 71 carrying the shaft 56 which drives the chains. The grinding-wheel is fed into the work by means of a nut 80 on the slide 13 engaging a screw 81 driven through gearing 83, 84, 86, 87 from a wheel 89 on a shaft 88, a hand-feed lever 92 on the shaft carrying an arm 94 provided with a micrometer adjustment 93, whereby the amount of feed may be adjusted, and wheel wear allowed for. The feed screw is rotated by an adjustable weight 143 connected to the screw by a chain 140 and sprocket 138, and the movement of the weight is controlled by a cam 110. The cam is mounted on a shaft 111 driven through worm and spur gearing from the shaft 43, variation of speed being provided for by mounting one of the gears 116. Fig. 3, on an angularly adjustable arm 120 and changing a co-operating gear 115. With the cam 110 engages a roller 133 carried by the arm 132 of a lever 130 pivoted at 131, and the sprocket 138 is carried by a member 135 mounted on the feed shaft 88 and adapted to be locked to the arm 94 bv a screw 137. The chain 140 has one end connected to a member 142 adjustable along an involute-shaped arm 145 forming the second arm of lever 130, whereby the amount of feeding stroke may be varied; the lower end of the chain is connected to the weight 143. The cam 110 is shaped to give first a rapid feed and then a slow feed, the feed mechanism during final grinding being held immovable by a stop; the wheel is withdrawn from the work by the abrupt rise of the cam. The stop comprises a screw 146, Fig. 9, mounted on a fixed bracket 148, positioned so that an abutment 149 on the arm 135 contacts therewith just before the roller 133 reaches the end of the in-feed part of the cam. The work-gripping members, which in the case of solid work hold this near the periphery, and in the case of hollow work also engage the bore, are carried by the axially movable spindles 20, 21. The spindles are moved by levers 150, 151, Fig. 3, pivoted at 152, 153 operated to grip the work by a weight 170 in a dashpot 210, and to release the work by cam mechanism. The lever 151 has an arm 157 pivotally connected at 158 to a connecting-rod 159 which also is adjustably connected to a lever 164, one arm of which carries the weight, and another arm of which has projections 163 engaging a projection 162 on the lever 150, whereby the spindles 20, 21 move simultaneously in opposite directions. The spindles are moved outwardly by a roller 180 on an arm 181 adjustable on the shaft 111, the roller engaging a projection 188 on an arm 187 carried on the pivot 158 and adjustably connected to the arm 187 carried on the pivot 158 and adjustably connected to the arm 187 to vary the movement of the work spindles. To suit different lengthsof work, the spindles are adjusted by means of nuts 204, 205 on threaded parts 200, 201 of the spindles, and a further adjustment is provided by varying the effective length of the rod 159 by threads thereon and lock-nuts 208. 209. The grinding-wheel is moved axially to eliminate grain marking and to equalize wear by means of a worm 215, Fig. 1, on the grinding-wheel spindlemeshing with a worm wheel 216 which rotates a cam 218. The cam engages a spring-pressed arm 220 pivoted at 219, the upper end of the arm engaging by means of rollers in a groove 222 in the worm; the axial movement may be stopped by a lever 225 having a cam 226 which moves the member 220 away from the cam 218. The work is fed into grinding position by means of a turret wheel 230 comprising plates 234 carried by a spindle 235, mounted in supports 236, the work pieces being placed on a surface 232 from which they roll into pockets 233 in the wheel. The wheel is turned intermittently by the weight of the work, the movements being timed by a ratchet 240 on the wheel engaged by a pawl 241 which is moved to allow the wheel to turn by the action of the abrupt rise of the cam 110 through the lever 130, levers 247, 245, and a rod 244; the ground pieces of work fall from the wheel and roll into a container. The work pieces are positioned axially by an adjustable spring carried by one of the supports 236, which presses the work against the other support. Solid work is held by cup members 255, 256, Fig. 3; hollow work is held centred by spring fingers carried by the work spindles and engaging the central opening of the work, the work being held by collars slidable on the spring fingers. In a modification, the turret wheel may be rotated intermittently by power through chain and ratchet gearing from the lever 130; in a further modification the wheel may be operated by the cooling water, acting in addition to the weight of the work, the wheel having pockets to receive the water.