| 摘要 |
A hollow drive spindle is rotatably mounted on a base and carries a self-opening threading die; and the spindle is driven by a suitable electric drive motor. An air operated collet chuck is mounted on a carriage, for reciprocating the chuck in longitudinal alignment with the threading die. The apparatus is semi-automatic in operation including an electric control circuit and actuator mechanisms operated in response to movement of the carriage. When the carriage reaches its rear limit position the chuck is opened to release the rod and the threading die is closed. When a rod is inserted in the chuck at the beginning of a cycle, it engages a stop arm so that further forward force on a rod also moves the carriage toward the die. With initial forward movement of the carriage, the chuck is closed on the rod and the stop arm is moved out of interference position. Further forward movement of the rod and carriage engages the rod with the threading die; and an adjustable actuator is tripped, at the selected limit of forward carriage movement, to open the threading die permitting withdrawal of the carriage and rod. A pair of forward limit actuator mechanisms, connected alternately in the control circuit, allow for the threading of two different lengths of thread on opposite ends of a rod. Alternatively, the threading head may be a tap or a non-opening threading die. The control circuit provides for automatic reversal of the threading head drive motor when the desired length of thread is cut.
|
