O.D. gripper

Apparatus for engaging and then pulling a projecting rod having a longitudinal axis through a rod support plate along the rod longitudinal axis, comprising:

• base means for engaging said support plate;
• a jacking assembly mounted on the base means and actuable by a first fluid pressure variation between extended and retracted positions away from and toward the base means, respectively;
• a substantially annular gripper assembly connected to the jacking assembly and adapted for engaging the rod coaxially about said rod longitudinal axis, the gripper assembly including,
• a housing having first and second longitudinal ends, first and second spaced apart surfaces oriented transversely to the rod longitudinal axis and a third surface extending between the first and second surfaces in parallel with the rod longitudinal axis so as to define a substantially annular gripper piston chamber between the first and second ends of the housing, conduit means in fluid communication with the gripper piston chamber, whereby a second fluid pressure variation can be introduced into the gripper piston chamber,
• gripper piston means for displacement within the housing in response to the second fluid pressure in the piston chamber, the gripper piston means including a substantially annular body portion situated in the chamber and having a first piston surface oriented transversely to the rod longitudinal axis and in juxtaposition to the housing first surface, a second piston surface oriented transversely to the rod longitudinal axis and in juxtaposition to the housing second surface, a neck portion extending rigidly from the body portion between the housing first surface and the rod longitudinal axis, a first piston seal between the body portion and the housing third surface, and a second piston seal between the neck portion and the housing first end,
• gripper means facing the rod longitudinal axis and supported between the body portion and the housing second end, for displacement toward the rod longitudinal axis to engage and grip the rod in response to the displacement of the gripper piston toward the second end of the housing when the second fluid pressure increases in the gripper piston chamber;
• and
• first and second fluid pressure ports associated respectively with the jacking assembly and the gripper assembly, whereby the gripper piston can be actuated and the jacking assembly extended to grip and pull the rod.

A pneumatically actuated tube gripper apparatus, comprising:

• a substantially annular housing defining a central longitudinal axis along which the tube is to enter the apparatus, the housing having,
• first and second longitudinal ends,
• a substantially annular groove intermediate the ends, the groove having first and second spaced apart surfaces oriented transversely to said longitudinal axis and a third surface extending between the first and second surfaces in parallel with said longitudinal axis so as to define a piston chamber between the first and second ends of the housing,
• fluid inlet means formed at the first end and extending into fluid communication with the piston chamber, whereby fluid at controlled pressure can be introduced into the piston chamber;
• piston means for displacement in the housing in response to the fluid pressure in the chamber, the piston means including,
• a substantially annular body portion situated in the chamber and having a first surface oriented transversely to said longitudinal axis and in juxtaposition to the housing first surface, and a second surface oriented transversely to said longitudinal axis and in juxtaposition to the housing second surface,
• a neck portion extending rigidly from the body portion between the housing first surface and said longitudinal axis,
• a first piston seal between the body portion and the housing third surface, and
• a second piston seal between the neck portion and the housing first end;
• and
• gripper means facing said longitudinal axis and supported between the body portion and the housing second end, for displacement toward said longitudinal axis to engage and grip the tube, in response to the displacement of the piston means toward the second end of the housing when the fluid pressure increases in the piston chamber.