GB1290124A - - Google Patents

Abstract

1290124 Grinding C W GEHRING 19 April 1971 [19 March 1970] 24168/71 Heading B3D A honing machine comprises a rotary drive 11 for a tool 10 for machining the bore or curved surface of a workpiece 6, and a torque sensitive device 12 responsive to the torque on the drive resulting from machining of the workpiece and coupled to a switch device operable to stop or stop and reverse the drive when the torque reaches a pre-adjusted limiting value. The tool 10 is mounted on a rod 9 connected through the torque sensitive device 12 to a spindle 8 on a carriage 4 slidable on vertical guides 3 to and from the workpiece 6 held by a device 5 on a machine table 7. The spindle 8 is rotatable by the drive 11 consisting of a geared motor. Because of the clearance between the holder 16 of the cutting bar 17 in the tool, the holder, in one direction of rotation of the tool is inclined in one direction. As the cutting bits 18 wear and form flats (19, Fig. 2b, not shown), the torque on the tool increases. When the torque reaches a predetermined value, the torque-sensitive device 12 acts, through an amplifier in a control panel 13 to a stop or stop and reverse the motor 11. Upon reverse rotation, the holders 16 are inclined in the opposite direction to bring a sharp edge of the flat (18) into contact with the workpiece.