| 摘要 |
In spinner tongs, a so-called spinner (30), incorporated in an iron roughnec k and thus serving to rotate a drill pipe during connection thereof to a drill string or during division of the drill string into individual pipes, the aim has been to reduce damage on the threaded connections (the pin-and-box joint s) in the screwing/unscrewing operations. This is realized in an operation for the simultaneous centring and rotating of the drill pipe. Four spinner rolle rs (42) known in themselves, which are brought to bear on the drill pipe when surrounding it, are mounted according to the invention, preferably in pairs, at the outer ends of driven clamping arms (46), by bogies (50). At their opposite outer ends the clamping arms (46) are pivotally supported on a fixe d frame part/structure (56) and are jointed to each other by means of a piston and cylinder (48) driven by pressure fluid and arranged to carry the clampin g arms (46) towards and away from each other. For their forced centring the clamping arms (46) have a centring stay (58) arranged thereto, which is connected by its outer end to one clamping arm (46), and is connected by its other outer end to the other clamping arm (46). For the parallel displacemen t of the rollers (42), each bogie (50) has a parallel stay (54) arranged thereto, whoseother end is supported on a fixed frame part/structure (56).</ SDOAB>
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