THREAD GRINDER PROVIDED WITH MEANS FOR RELIEFFGRINDING THREAD IN INTERNAL THREAD CUTTING AND INTERNAL THREAD FORMATION

摘要

A relief thread grinding machine for making screw taps wherein a workpiece 10 is clamped to a resiliently mounted body 5 of a longitudinally adjustable sled 1. The body carries a follower wheel 17 which bears on a cam roller 15 rotatably mounted on the sled. The surface of the cam roller is eccentrically lobed so that when it is axially moved varying oscillation strokes of the body 5 are produced. The cam roller can be axially adjusted as needed during the grinding process so that the amount of relief grind can be changed. In this manner it is possible to provide the conical thread on the lead end of a tap with a different relief grind than the generally cylindrical and posteriorly weak conical thread on the guide end of the tap.