GB1400063A - Automatic infeed mechanism for a grinding wheelhead - Google Patents

Abstract

1400063 Grinding TOS HOSTIVAR NARODNI PODNIK 3 Aug 1972 [4 Aug 1971] 36347/72 Heading B3D [Also in Division C7] An automatic in-feed mechanism for the wheelhead of a grinding machine comprises hydraulic piston and cylinder means and gear elements whereby following a quick infeed, the workpiece is electrolytically ground by "deep infeed", in which the grinding wheel is fed into the work for the full depth of cut and the workpiece rotated through one revolution, and there after the electrolytic grinding is terminated and a finishing fine grinding effected with the workpiece rotating at a higher speed. The mechanism consists of a rack 8 on the wheelhead 9 connected by gears 6, 7, to a worm 5 on a shaft 4. One end of the shaft is secured to a piston 24 in a quick infeed cylinder 21 integral with a "deep infeed" cylinder 22 having a piston 25 on a rod 23 adjustable by a nut 26. The other end of the shaft is splined to a gear 13 meshing through planet wheels 12a with a toothed ring 12 which can be rotated for coarse adjustment of the wheel head by a hand wheel 10 and gear 11 and for fine adjustment by a wheel 14c, and gearing 14, 14a, 14b. The gear 13 is also connected through gears 15, 15a to a rack 19 movable by the piston 17a of a finishing grinding cylinder 17. A pump 31 is connected to a valve 33 having conduits connected to one end of each of cylinders 17, 21 and to one end of an hydraulically operated valve 34. The other end of cylinder 17 is connected to a valve 39 which can be opened by a solenoid operated valve 40 so that flow from the cylinder passes through a regulator 36b. The valve 34 controls the flow to the cylinder 22, flow from the right hand end being controlled by a regulator 35a. Operation of the valve 33 by a lever 33b direct fluid to the left hand end of the guide infeed cylinder 24, to the left hand end of valve 34 and to the right hand end of cylinder 17, the piston 17a of which is held against movement by the valve 39. Piston 24 moves rod 4 to effect the quick infeed of the wheelhand. Simultaneously, operation of valve 34 directs fluid to the left hand end of the "deep infeed" cylinder 22; the piston 22 moves at a speed determined by the regulator 35a for effecting the "deep infeed" during the electrolytic grinding, the rod 4 of piston 24, after the quick infeed, abutting rod 23 of piston 25 which thereby controls the deep infeed. The nut 26 determines the limit of travel of the cylinder 22. At the end of the travel, the valve 40 is actuated to open the valve 39 so that the finishing grindis effected at a speed determined by the regulator 36b, "spark-out" being effected at the end of movement of the piston 17a.