1,017,578. Grinding. H. SAUTER, and W. HAHN, [trading as HAHN & KOLB]. Feb. 11, 1964 [Feb. 12, 1963], No. 5598/64. Heading B3D. A grinding-machine for grinding cutting tools, such as drills, millers, reamers, comprises a headstock 1, Fig. 5, which is rotatably adjustable about a vertical axis 3, carries a horizontal spindle 23 for carrying the tool, and is mounted on a slide 2 displaceable along a guide member 5 for longitudinal movement of the tool, a carrier 24 secured to the member 5 and carrying a plate 25 which is rotatably adjustable about a vertical axis and formed with a guide 28 accommodating a rotatable slide 29 mounted on a rack 30 displaceable in the headstock to rotate through gearing the spindle 23, a shaft 57 extending from the headstock for direct actuation of the gearing and spindle, and a differential connecting the tool spindle with a second shaft 39 carrying an indexing head 47 which connects the second shaft with a bearing bush 42, or disconnects the shaft from the bush for direct rotation of the spindle, the bush being rotatably adjustable. The slide 2 carries a worm shaft 18 which engages a worm-wheel 17 connected by gearing to a lever 12 which can be rocked to effect a coarse movement of the slide 2 along the guide member 5, the shaft 18 being rotated by a crank handle to effect fine adjustment of the slide. The guide member 5 is adjustable along a second guide 6 by rack-and-pinion gearing 9, 10, and the second guide is transversely adjustable on a table 7 by a screw 11. The tool spindle 23 is rotatably mounted in the headstock 1 and is secured to a sun gear 37 of the differential. The sun gear 37 meshes with planet wheels 40, 41 on a carrier 36 having a gear 35 which, on the one hand, meshes with a gear 34 on a shaft 33 connected by gearing 31, 32 to the rack 30, and, on the other hand, meshes with a gear 54 connected by gearing 55, 56 to the shaft 57 which is rotatable by a hand crank; the rack 30 carries the rotatable slide 29 engaging the guide 28 formed in the undersurface of the plate 25 which is rotatably adjustable by a gear 26 to set the guide to an angle corresponding to the helix of the tool. The planet gears 40, 41 also engage a sun gear 38 on the second shaft 39 which is rotatable in the bush 42 and carries the indexing head 47 having a pin 48 for engagement with an indexing plate 49 carried by the bush 42 which is rotatably adjustable by worm gearing 43, 44. In operation, the bush 42 is rotated by the worm gearing 43, 44 to initially adjust the position of the spindle and tool about their axis. If the helix of the tool to be ground is such that the plate 25 is set to a position in which the angle between the guide 28 and spindle 23 is 40 degrees or less, the movement of the headstock can be effected by movement of the lever 12 and rotation of the spindle 18 to axially move the spindle and tool at a coarse and then a fine speed, the movement of the headstock relative to the plate 25 causing the slide 29 to impart movement to the rack 30 and gearing 31 . . . 35 to rotate the planet wheels 40, 41 about the sungear 38, which is held fast by the indexing mechanism 47, 49, the planet wheels, in turn rotating the sun gear 37 and tool spindle 23. If the helix is such that the angle between the guide 28 and spindle 23 is greater than 40 degrees, the shaft 57 is rotated by a hand-crank to rotate the gear 35 which rotates the planet wheels and sun gear 37 to rotate the spindle 23 and displace the rack 30 and slide 29 along the guide 28 so that the headstock moves the spindle and tool which are thereby moved axially while rotated. If the guide 28 is adjusted to be parallel to the spindle, movement of the headstock is effected without rotation of the spindle. With the guide adjusted to be perpendicular to the spindle, rotation of shaft 57 causes rotation of the spindle with no movement of the headstock. The pin 48 of the indexing head can be disengaged from the indexing plate 49 by operation of a screw 52 and a crank fitted to a plate 51 on the shaft 39 to rotate the tool spindle 23 through the planet gears 40, 41 and sun gears. An attachment may be fitted to the headstock so that the tool is carried by head and tail centres. The table 7 of the machine also supports a grinding head 71 consisting of a base 72, Figs. 1 and 2 (not shown), rotatably adjustable about an axis 85 and carrying a column 73 which is adjustable by a screw 78 radially of the axis. The column carries a grinding wheel head 74 which is vertically adjustable on the column by a screw 80 and is rotatably adjustable about an axis transverse to the column to position the plane of the wheel horizontally or vertically. The grinding-wheel may be of pot or conical shape. Cooling water is supplied to the grinding-wheel by a flexible pipe connected to a pump and tank in the machine frame.