| 摘要 |
Disclosed herein is a power tongs, including a rotary head and a circular plate loosely mounted on the head, with a flexible member secured at one end to the plate. The flexible member is wrapped around the pipe to be torqued and the free end of the member is tensioned around the pipe by means of a lever that is pivotally supported on the plate, the lever having an outwardly extending arm that is engaged by a pin extending upward from the rotary head as the tongs are operated. The flexible member distributes radial loads over the surface of the pipe to prevent crushing of the pipe and damage to its surface.
|
