GB1137989A - A method of and an apparatus for setting and trueing grinding wheels or discs - Google Patents

Abstract

1,137,989. Trueing. MASCHINENFABRIK KARL HACK K.G. 22 Feb., 1967 [24 Feb., 1966], No. 8418/67. Heading B3D. In the setting and trueing of grinding wheels or discs, at least one grinding wheel or disc and one trueing tool are relatively movable towards one another and the trueing tool is positioned in the path of relative movement between the grinding wheel or disc and trueing tool such that after the grinding wheel or disc contacts said trueing tool the relative movement towards one another between the trueing tool and grinding wheel or disc is stopped so that the wheel or disc is in the set position relative to the trueing tool and can be trued in such position. Grinding discs 4, 4a, Fig. 1, e.g. of a spring end grinding machine, are movable axially by feed screws 30, 30a driven by motors 31, 31a controlled by means 34. Trueing wheels 3, 3a movable into the advancing paths of the discs are mounted on shafts 35, 35a: rotation of the shafts operates contacts in units 36, 36a connected to the control means 34. The contact may comprise a magnetic ring (39, Fig. 2) fixed in the end of the shaft and coil (40) within the ring, so that on rotation of the shaft a current is induced in the coil; alternatively, spring arms (42, Fig. 3) projecting axially beyond the end of the shaft carry contacts (41) which, when the arms move out centrifugally due to rotation of the shaft, make contact with a sleeve (43). The distance 38 between the trueing wheels corresponds to the length to which the springs are to be ground. By manual or automatic operation of the control means 34 the grinding discs are moved singly or simultaneously until each contacts its trueing wheel thus operating the contacts in units 36, 36a. The trueing wheel is retracted, while advance of the grinding disc continues for a period, after which the trueing tool is advanced to effect trueing. A modification, Fig. 4, has means for compensating for wear of the trueing wheels 3, 3a. The latter are mounted on a support 1 movable by a piston 5 in a cylinder 6 under control of a valve 9. The diameter of the trueing wheels is sensed by feelers 24, 24a co-operating with members 14, 15 on a control rod 16 linked to a valve 13 in the fluid exhaust. To compensate for wear of the trueing wheel 3a, support 1 is moved upwardly until feeler 24a engages member 15 to move rod 16, thus closing valve 13 so stopping upward movement of support 1. Wear of trueing wheel 3 is similarly compensated. Trueing is effected as in the first embodiment.