| 摘要 |
A backup tong 10 secures the tubular against axial rotation in response to rotation by a power tong. The backup tong plate 20 supports a pair fluid powered cylinders 32, 34 , and a pair of swing arms 50, 52 each pivotally connected to the respective fluid powered cylinder. A left side cam plate 44 and a right side cam plate 46 are each provided for cooperation with a respective left side and right side cam follower 58, 60 . The gripping head 30 provided on the backup tong plate, and a pair of gripping heads 62, 64 are provided on a forward end of each of the swing arms for gripping the tubular. A method of the invention includes supporting the fluid powered cylinders on the backup tong plate, and pivotally connecting the swing arms to the respective fluid powered cylinders. The cam followers move within respective cam plates during actuation of the cylinders. |
