GB697949A - Improvements relating to the control of grinding machines - Google Patents

Abstract

697,949. Grinding. FORTUNA WERKE SPEZIALMASCHINENFABRIK AKT. - GES. June 13, 1952 [June 16, 1951], No. 14915/52. Class 60. [Also in Group XXIX] Means for automatic regulation of the grinding wheel speed in grinding machines is characterised by the feature that the grinding surface or grinding edge of the grinding wheel is placed in the path of a jet and a measuring appliance associated with the jet operates a relay when the measured value changes as the grinding surface moves out of the jet, which relay adjusts the position of the jet and at the same time the speed of the grinding wheel. A nozzle 4 is carried by the rod 2 of a piston 15 so that on displacement of the rod 2 the nozzle 4 moves parallel to the side of the grinding wheel 1 and so close to the wheel that a jet of cooling water leaving the nozzle encounters a resistance at the wheel which results in an increase in the pressure in a pipe 5 supplying water to the nozzle. The pipe 5 is connected to a gauge chamber 6 having a movable diaphragm 7 which operates through rod 8 a valve 9 loaded by a spring 19. The valve 9 controls the admission of pressure oil to, and exhaust from, one end 12 of the cylinder 3 containing the piston 15. The pressure of the jet is adjusted by a throttle valve 16 so that in the normal operating position of the jet the pressure in the gauge chamber 6 reaches such a value that the control valve 9 is in a central position, in which the cylinder space 12 is cut off from both supply 17 and exhaust 18. The piston rod 2 is acted on by a spring 13 and is toothed to engage a pinion 10 which controls an infinitely variable gear in the grinding wheel drive. In operation, as the wheel wears, the jet automatically follows the edge and the angular velocity of the wheel is automatically increased to maintain the peripheral speed constant.