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US 4,732,061 AGranted
Power tongs and clamping units therefor
AssigneeNational-Oilwell, L.P.
InventorMichael C. Dinsdale
Life of this patent
Estimating the term…
Abstract
A power tong has upper and lower clamping units mounted in a suspended support frame. Each clamping unit has pipe clamping jaws that move rectilinearly, and are actuated by a pressure fluid operated linear actuator. The lower clamping unit is rigidly secured to the supporting frame and the upper clamping unit is rotatable relative to the lower clamping unit. The relative rotation in both directions is accomplished by a remote powered actuator.
Claims14
In a clamping unit for power tongs to be used for making and breaking threaded pipe connections, the combination of rigid support means having a front, a back and two sides,
- the support means having an opening to accommodate a pipe or a threaded connector member, the opening extending through the front of the support means so that relative lateral movement between the support means and a pipe or connector member can cause the pipe or connector member to be situated in a predetermined position in the opening,
- the support means being adapted to be so mounted in a power tongs as to be rotatable about the longitudinal axis of the pipe connection to be made or broken;
- two opposed jaw members each disposed between the opening and a different side of the support means,
- the jaw members being supported for rectilinear movement toward and away from the opening so as to be capable of being engaged with and disengaged from a pipe or connector member disposed in the opening;
- two jaw actuating levers each disposed between a different one of the sides of the support member and the one of the jaw members nearer such side, each of the jaw actuating levers being mounted on the support means for pivotal movement about an axis parallel to the axis of rotation of the support means, each of the levers having
- a front portion projecting forwardly from the axis of pivotal movement of the lever, and a back portion projecting rearwardly from the axis of pivotal movement of the lever;
- remotely operable double acting linear power device connected between the ends of the back portions of the jaws actuating levers and operative to pivot the levers in a first direction when the power device operates in one direction and a second direction when the power device operates in the opposite direction;
- and
- linkage means interconnecting the jaw members and the jaw actuating levers to move the jaw members toward each other, to clamp the pipe or connector member, when the power device is operated in said one direction, and away from each other, to release the pipe or connector member, when the power device is operated in said opposite direction, the linkage means comprising
- first means interconnecting the front portions of the levers and the respective jaw members but leaving the opening free for entry of the pipe or connector member, and
- second means interconnecting the back portions of the levers and the respective jaw members and being located between the power device and the opening.
8 more elements
In a power tongs unit for making and breaking threaded pipe connections, the combination of
- a support frame having a front and a back and being open at the front to accommodate the threaded pipe connection to be made or broken;
- two clamping units carried by the support frame and each comprising
- a rigid support having a front, a back and two sides and having an opening extending through the front of the rigid support, the rigid support being so located relative to the support frame that the front of the rigid support and the front of the support frame face in the same direction, the opening of the rigid support being dimensioned to accommodate the threaded pipe connection to be made or broken, the rigid support of at least one of the clamping units being so mounted on the support frame as to be rotatable relative to the support frame about the longitudinal axis of the threaded connection to be made or broken,
- two opposed jaw members each disposed between the opening and a different side of the support means, the jaw means being support for rectilinear movement toward and away from the opening so as to be capable of being engaged with and disengaged from a pipe or connector member disposed in the opening;
- two jaw actuating levers each disposed between a different one of the sides of the rigid support and the one of the jaws nearer such side, each of the jaw actuating levers being mounted on the rigid support for pivotal movement about an axis parallel to the axis of rotation of the rigid support, each of the levers having a front portion projecting forwardly from the axis of pivotal movement of the lever, and a back portion projecting rearwardly from the axis of pivotal movement of the lever,
- a remotely operable double acting linear power device connected between the ends of the back portion of the jaw actuating levers and operative to pivot the levers in a first direction when the power device operates in one direction and a second direction when the power device operates in the opposite direction, and
- linkage means interconnecting the jaw members and the jaw actuating levers to move the jaw members toward each other, to clamp one part of the threaded connection to be made or broken, when the power device is operated in said one direction, and away from each other, to release the threaded connection, when the power device is operated in said opposite direction, the linkage means comprising first means interconnecting the front portions of the levers and the respective jaw members but leaving the opening of the rigid support free for entry of the threaded pipe connection to be made or broken, and second means interconnecting the back portions of the levers and respective jaw members and being located between the power device and the opening of the rigid support;
- and
- remotely operable power means connected to the clamping units for rotating one of the clamping units relative to the other.
6 more elements
Dependencies are inferred from the claim text.