GB1107974A - Grinding - Google Patents

Abstract

1,107,974. Grinding. B. E. DOWNS, and K. G. NEWEY. 22 Dec., 1966 [23 Dec., 1965], No. 54761/65. Heading B3D. A feed control device 25, Fig. 1, for infeed control of a centreless grinding machine having a rotatable grinding wheel 11, a control wheel mounted on a slide 14 to rotate on an axis parallel with or inclined at a small angle to that of the grinding wheel, the control wheel and grinding wheel being aligned in substantially co-planar relationship and the control wheel being movable with the slide towards and away from the grinding wheel, the control device comprising fluid pressure operated control means adapted for mounting on a centreless grinding machine and operable to control the feeding of the control wheel towards and away from the grinding wheel. The slide 14 carries the control wheel and a work rest 21 and is movable along a guideway 15 on the machine bed 10 by rotation of a hand wheel 19 connected to a lead-screw 17 which is rotatable in a bracket 18 on the bed and engages a nut 20 on the slide. Rotation of the screw is used to initially adjust the slide and thereafter the screw is looked in position by a lever 24, the infeed of the control wheel then being effected by rotation of the nut which is secured by a clamp 33, Fig. 3, to a lever 32 of the control device. The lever is formed with a slot 31 engaged by a roller 30 on a block 29 slidable in a guide structure 28, the block being connected to the rod 41 of a pneumatic cylinder and, through a lost-motion connection 47, 48 to the rod 45 of an hydraulic damper 44. During automatic operation, the supply to cylinder 40 is controlled by valves V1, V2 actuated by pins 49, 50 secured to the block. A third valve V3 is actuated when an edge 56 of the block engages a trigger 53 to operate the cylinder of a device associated with the work rest 21 for ejecting a finished workpiece. A pneumatic circuit is described which permits single or continuous grinding cycles to be effected. During infeed, the control wheel is advanced rapidly until the damper is operated to oontrol the rate of grinding. At the end of the infeed, grinding continues under the control of a regulator for a predetermined time before the wheel is retracted. In an alternative embodiment, the nut 20 has a pinion engaged by a rack on the piston-rod 41.