GB1250133A - - Google Patents

Abstract

1,250,133. Grinding. C. W. GEHRING. 16 April, 1970 [17 April, 1969], No. 18099/70. Heading B3D. An hydraulic feeding device for controlling the feeding movement of a honing tool H comprises an hydraulic piston and cylinder system which is non-rotatably connected to the honing tool and is designed as a rotary valve operable in response to frictional engagement of the tool with the workpiece to at least partially close a control bore to stop or nearly stop a fast feed of the stones H 1 , H 2 of the tool and permit fine feeding of the stones. The body of the honing tool is connected to the cylinder 2 of the system and the cones K 1 , K 2 for adjusting the stones H 1 , H 2 are connected to the rod K which extends through a stuffing box S and is connected to the piston 1. The cylinder is rotatable by an extent limited by pins 8 engaging grooves 10 in a housing 3 and has transverse bores 13, 21 leading from cylinder space 35 and co-operating with longitudinal bores 15, 23 in the housing connected by a distributer 20 to conduits 34, 36. The space 27 above the piston is connected by a bore 24 to a conduit 33. Conduits 33, 34 are connected by a reversing valve 32 to a pump P and tank T, and conduit 36 is connected to a throttle valve 37, an open/ closed valve 38 and tank P. In operation, the valve 38 is initially closed and valve 32 directs fluid through conduit 33 to lower position 1 so that the cones rapidly expand the hone, exhaust fluid passing through bores 13, 15 to conduit 34. When the honing stones frictionally engage the workpiece, the resistance causes a rotation of the cylinder 2 relative to the housing to an extent determined by the pins 8 and grooves so that the bore 13 is disconnected from bore 14 and the rapid expansion stopped. The valve 38 may then be operated continuously or intermittently to connect the conduit 36 through the throttle valve 36 to the tank to effect the fine feed.