Threading machine die head.

摘要

The thread cutting die head (10) for a power driven threading machine is comprised of an annular support plate assembly (12) supporting a plurality of radially displaceable threading cutting dies (42) spaced apart about the axis (A) of the die head (10), and a cam plate assembly coaxial with and pivotal relative to the support plate assembly (12) to radially displace the cutting dies (42). The cam plate assembly is spring biased to pivot relative to the support plate assembly (12) in the direction to radially retract the cutting dies (42), and pivoting in the latter direction is controlled by a keeper (88) mounted on the support plate assembly (12) and engaging a keeper track (84) on the cam plate assembly. The keeper (88) is mounted on the support plate assembly (12) for pivotal displacement about a keeper axis (94) parallel to the die head axis (A), and pivotal displacement of the keeper (88) is controlled by a lever mechanism (112) actuated by a workpiece (W) being threaded to provide for progressive displacement of the cam plate assembly and receding displacement of the cutting dies (42) during the threading operation.