| 摘要 |
<p>An open throat power tong 10 for making up and/or breaking apart an oilfield tubular connection includes an open throat in the tong body 15. Motors 18, 20 rotate a partial ring member 12 and a pair of heads 16 with respect to the tong body. A door 40, 140 may be opened to expose the open throat of the power tong, and has a planar latch surface formed from arcuate groove 58 for receiving an arcuate boss 90. The door latch mechanism reduces the effort required to safely latch the door in the closed position before operating the tong, and provides a highly reliable mechanism to minimize spreading of the tong body under a relatively high torque.</p> |
