Modular adapter for tongs

Abstract

An adapter for supporting a tong includes a leveling frame and a suspension for supporting the tong on the leveling frame. The suspension includes an axially movable member mounted to an upper surface of the leveling frame and a receptacle mounted to the tong for receiving the movable member.

1 . An adapter for supporting a tong, comprising:
 a leveling frame;   a suspension for supporting the tong on the leveling frame, the suspension having:
 an axially movable member mounted to an upper surface of the leveling frame; and 
 a receptacle mounted to the tong for receiving the movable member. 
   
     
     
         2 . The adapter of  claim 1 , wherein the axially movable member comprises:
 a cylindrical housing mounted to the leveling frame; and   a mandrel disposed in the housing and axially movable relative to the housing.   
     
     
         3 . The adapter of  claim 2 , wherein the axially movable member further comprises:
 a compression spring disposed between the mandrel and the leveling frame; and   a ball stud disposed on the mandrel.   
     
     
         4 . The adapter of  claim 3 , wherein the receptacle comprises:
 a cylindrical shroud having an inner diameter greater than an outer diameter of the respective housings, thereby forming an outer clearance therebetween; and   a ball socket disposed in the shroud and having a seat diameter greater than a ball diameter of the ball stud.   
     
     
         5 . The adapter of  claim 1 , wherein a travel range of the suspension in each of the vertical directions is greater than or equal to ten millimeters. 
     
     
         6 . The adapter of  claim 1 , wherein the leveling frame is connected to a main frame. 
     
     
         7 . The adapter of  claim 6 , further comprising a torsional arrestor torsionally connecting the leveling frame to the main frame. 
     
     
         8 . The adapter of  claim 7 , wherein:
 the torsional arrestor comprises a pair of rails extending upwardly from the base, and   the main frame further having a girder connected to the rails and disposed between the leveling frame and the base.   
     
     
         9 . The adapter of  claim 8 , wherein:
 the torsional arrestor further comprises a linear bearing disposed in each rail, and   each linear bearing is fastened to the leveling frame.   
     
     
         10 . The adapter of  claim 9 , wherein each linear bearing comprises:
 a body;   an outer roller disposed around the body and free to rotate relative thereto about a first horizontal axis; and   an inner roller disposed in the body and free to rotate relative thereto about a second horizontal axis perpendicular to the first horizontal axis.   
     
     
         11 . The adapter of  claim 6 , further comprising an actuator for raising and lowering the leveling frame relative to the main frame. 
     
     
         12 . The adapter of  claim 11 , wherein a stroke length of the linear actuator corresponds to a makeup length of casing joints. 
     
     
         13 . The adapter of  claim 12 , wherein:
 the linear actuator comprises a pair of piston and cylinder assemblies disposed in the rails, and   upper ends of the piston and cylinder assemblies are pivotally connected to the rails, and   lower ends of the piston and cylinder assemblies are pivotally connected to the leveling frame.   
     
     
         14 . The adapter of  claim 6 , further comprising a base attached to the main frame, the base supporting a second tong. 
     
     
         15 . The adapter of  claim 1 , further comprising:
 a torsion tube extending underneath a body of the tong and having arms attached to ends of the tong body;   wherein:   each arm is pivotally connected to a respective side of the tong body, and   the leveling frame has lugs connectable to the arms.   
     
     
         16 . The adapter of  claim 1 , further comprising:
 a control system mounted to the tong,   wherein the leveling frame further has a bracket for receiving an electrical power cable for connecting the control system to an electrical power source.   
     
     
         17 . The adapter of  claim 1 , wherein a travel range of the suspension in each of the horizontal directions is greater than or equal to ten millimeters.