Abstract: Damage to pipe resulting from non-uniform application of gripping forces is minimized by modified power tongs employing pivoting jaws which automatically adjust to the circumference of the pipe. The pivoting jaws pivot about mounting pins which pass through an elongated aperture in the jaw. The aperture is elongated in a direction which allows the arcuate pipe-gripping surface on the jaw to align itself concentric with the outer surface of the pipe so that the gripping force applied by the jaw is uniformly distributed over the arcuate pipe-gripping surface of the jaw.

Abstract: Apparatus for gripping tubular members including self aligning gripping jaws with high coefficient of friction for resisting force applied to the elongated member to prevent rotation either clockwise or counterclockwise. Linear cams and cam rollers actuated by a fluid cylinder bring the gripping jaws to an elongated member, applying predetermined gripping force and retract the jaws for removal of the elongated member.

Abstract: Apparatus for gripping tubular members including self aligning gripping jaws with high coefficient of friction for resisting force applied to the elongated member to prevent rotation either clockwise or counterclockwise. Linear cams and cam rollers actuated by a fluid cylinder bring the gripping jaws to an elongated member, applying predetermined gripping force and retract the jaws for removal of the elongated member.

Abstract: Bi-directional gripping apparatus having a double-seated linkage supports a jaw within a housing so that the jaw may be used to grip an elongated body and exert force thereon in opposite directions. The jaw is mounted to exert radial force in either direction or axial force in either direction.

Abstract: Power tongs and the back-ups are disclosed which have improved means for gripping pipe and tubular members. Torque is applied and held with minimum damage to the pipe or tubular member. A plurality of gripping assemblies, each consisting of a pivoted jaw having a friction surface, are mounted on a drag ring. Rotational resistance is selectively applied to the drag ring to cause the jaws to make contact with or be released from the pipe prior to any torque being applied to the pipe. Various modifications of the gripping assemblies are disclosed to provide better gripping contact with the pipe.

Abstract: Interfering bosses are provided on the jaw and jaw link forming a pivoting jaw assembly for a power tong or back-up. The bosses are arranged to interfere and prevent over-center rotation of the jaw with respect to the jaw link. The jaw is pivotally mounted on the jaw link with a pin journaled in an aperture which is elongated in the direction of the axis of the bosses so that the jaw can be rotated over-center when desired.

Abstract: A cylinder gripping apparatus having a jaw, a body and a floating interfacing assembly having a curved surface bearing against an opposing surface or groove, the interfacing assembly being operable to generate a proportional gripping force in response to an axial force upon the cylinder to be gripped. The jaw is not connected to the body. The interfacing assembly is operable to permit a transverse displacement of the jaw.

Abstract: A hydrostatic testing apparatus for capping an open end of a pipe, tube or cylinder is disclosed.A seal is provided to facilitate a fluid-tight seal between the pipe and the body. The seal has relatively long lips which facilitate a sealing engagement upon dirty or rough pipe surfaces. The seal is pre-stressed by lugs to sealingly engage the pipe under low pressure conditions.Adaptors, a centralizer having replaceable cam pieces, and replaceable jaw tooth segments facilitate the testing of a variety of pipe sizes and shapes with a single apparatus. An air purge valve is provided, in cooperation with passageways, to facilitate the expungement of air and gas from the interior of the body and pipe.A jaw design is disclosed which permits the side of the jaw to evenly grip the pipe by providing a pivotal attachment between the jaw and translator that is parallel to the axis of the pipe.

Abstract: This disclosure is directed to a temporary enclosure for a pipe. It includes a recessed opening in a body having an internal O-ring seal mechanism for engaging the end of a pipe. It is held to the pipe by incorporating a surrounding lip about the exterior of the pipe. The lip supports at spaced locations around the periphery three or four sets of pipe gripping devices. Each set incorporates a link which is pivoted to an arcuate body having serrated teeth on the innerface which contacts the pipe. As pressure is increased in the pipe, the device is forced off of the pipe. When this occurs, the connective link rotates, causing the peripheral gripper with teeth to bite into the pipe and thereby grip and hold the pipe.

Abstract: A cylinder gripping apparatus having a jaw, a body and a floating interfacing assembly having a curved surface bearing against an opposing surface or groove, the interfacing assembly being operable to generate a proportional gripping force in response to an axial force upon the cylinder to be gripped. The jaw is not connected to the body. The interfacing assembly is operable to permit a transverse displacement of the jaw.