| 摘要 |
<p>The power driven pipe threading machine is provided with a coolant system by which an oil free, glycol based coolant is dispensed onto the workpiece (w) during thread cutting in the area thereof adjacent a thread cutting die (38) at a rate which provides for the coolant to completely evaporate and for the workpiece (w) to be cooled to a temperature which provides a good quality thread. The coolant is pumped from a reservoir (58) to a coolant outlet (66) on the die head (36) of the machine and through a needle valve (64) by which the discharge rate is adjustable, and a torque responsive shutt-off valve (62) is associated with the die head (36) for controlling the flow of coolant from the reservoir (58) to the needle valve (64) and coolant outlet (66) in response to initial threading engagement between the workpiece (w) and cutting dies (38) on the die head (36).</p> |
