MACHINE PIPE WRENCH Russian patent published in 1995 - IPC

FIELD: drilling equipment. SUBSTANCE: at first lagging occurs thanks to rolling of gripping link 3 about its toothed die 20. In this case joint 14 comes closer to pipe circumscribing circle till butt 11 of lever 1 touches limiter 10 of gripping link 9. Further growth of pressing of gripping links 3, 4, 5, 6, 7, 8, 9 against pipe will rise as growth of torque will take place thanks to turn of lever 1 while its butt 11 slides over limiter 10. EFFECT: prevention of overloading, reduced masses of gripping links, increased handling convenience and safety. 3 cl, 6 dwg