GB1505149A - Device for precision feed in a machine tool - Google Patents

Abstract

1505149 Grinding LIDKOPINGS MEKANISKA VERKSTADS AB 13 Aug 1975 [14 Aug 1974] 33763/75 Heading B3D Apparatus for moving a workpiece or tool carrier of a machine tool comprises a shaft 9 for effecting the movement of the carrier, a disc 16 fixed to the shaft, a releasable coupling element 19 for frictionally engaging the disc, and reciprocative means 18 for acting on the coupling element in such a way that when the element is engaged with the disc, the disc is rotated and thus effects a rotary motion of the shaft. As described, the machine tool is a grinding machine having a grinding wheel 3 which is to be finely adjusted to compensate for changes in its dimensions resulting from dressing. The wheel is mounted on a head 1 movable along a bed 2 upon rotation of a screw-threaded rod 5 which engages the head and is supported for rotary but not axial movement in a bracket 6. Rotation of the rod to provide a mainly rapid feed is effected by a hand wheel 10 connected by chain drives 11, 12 to the rotatable shaft 9 which, in turn, is connected to the rod 5 by backlash-free worm gearing 7, 8. The fine adjustment of the grinding wheel is effected by movement of the disc fixed to the shaft 9. A lever 17 is mounted on bearings 27 on the shaft and at one end has the element 19 for frictionally coupling the lever to the disc and consisting of a piston 28 movable in a cylinder 28 for clamping engagement with the disc. The other end of the lever co-operates with a piston-and-cylinder device 18, operation of which effects rotary motion of the lever and hence the shaft 9 when the element 19 is clamped to the disc. The movement of the lever is limited by stops 20, 21 combined with sensing and pulse-generating elements which control the device 18 and the coupling element 19. The nozzle of rotation of the lever 17 is adjustable by rotation of a lever arm 22, 25 which is connected to the device 18 and by a shaft 24 to a hand wheel 23.