Packoff subassembly

Abstract

A packoff subassembly comprises a body threadedly engaged with a hub having a camming surface extending outwardly therefrom. The body is moved upward forcing the camming surface comes into engagement with an elastromeric seal thereby forcing the seal outwardly into sealing engagement with the surrounding surface.

1 . A packoff subassembly comprising: 
 a body having a first camming surface extending outwardly therefrom;    a second camming surface supported on the body for movement toward and away from the first camming surface;    an elastomeric seal supported on the body between the first camming surface and the second camming surface; and    means for selectively moving the first camming surface and the second camming surface toward one another and thereby forcing the elastomeric seal outwardly from the body and into sealing engagement with the surrounding surface.    
   
   
       2 . The packoff subassembly according to  claim 1  wherein the first and second camming surfaces face one another, and wherein the elastomeric seal comprises opposed surfaces engaging the first and second camming surfaces.  
   
   
       3 . The packoff subassembly according to  claim 1  further including: 
 a first camming member secured to the body and having the first camming surface formed thereon; and    a second camming member supported on the body and having the second camming surface formed thereon; and    the second camming member and the body being supported for relative sliding movement with respect to each other.    
   
   
       4 . The packoff subassembly according to  claim 3  wherein the first camming surface extends toward the second camming member and angularly outwardly relative to the body, and wherein the second camming surface extends toward the first camming member and angularly outwardly relative to the body.  
   
   
       5 . The packoff subassembly according to  claim 4  further characterized by a threaded member for effecting relative movement between the body and the second camming member.  
   
   
       6 . A packoff subassembly comprising: 
 a cylindrical body;    a first camming member fixedly secured to one end of the cylindrical body;    a first camming surface formed on the first camming member;    a second camming member supported on the body;    a second camming surface formed on the second camming member;    a second camming member and the body being supported for relative sliding movement with respect to each other;    the first camming surface and the second camming surfacing facing one another;    an elastomeric seal supported on the cylindrical body between the first camming surface and the second camming surface; and    means for effecting relative sliding movement between the second camming member and the body in a direction that moves the first camming surface and the second camming surface toward one another thereby forcing the elastomeric seal outwardly and into engagement with a surrounding surface.    
   
   
       7 . The packoff subassembly according to  claim 6  wherein the first camming surface extends angularly outwardly from the body and toward the second camming member; 
 the second camming surface extends angularly outwardly from the body and toward the first camming member; and    the elastomeric seal comprises surfaces mounted in engagement with the first and second camming surfaces.    
   
   
       8 . The packoff subassembly according to  claim 7  wherein the first camming member is cylindrical in shape and is characterized by a predetermined diameter; 
 the second camming member is cylindrical in shape and is characterized by a predetermined diameter substantially identical to the diameter of the first camming member; and    the elastomeric seal is cylindrical in shape and is characterized by an initial diameter which is substantially identical to the diameters of the first camming member and the second camming member.    
   
   
       9 . The packoff subassembly according to  claim 8  further including a hub extending from the end of the body remote from the first camming member and comprising a threaded section located immediately adjacent the intersection of the hub and the body; and 
 a nut threadedly engaged with the hub for selectively effecting relative sliding movement between the second camming member and the body.    
   
   
       10 . The packoff subassembly according to  claim 9  further including a plurality of threaded apertures formed in the second camming member for securing the packoff subassembly in engagement with an end of a length of pipe.  
   
   
       11 . A packoff subassembly comprising: 
 a cylindrical body having an upper and lower end;    the lower end of the body having an angled camming surface extending outwardly therefrom;    a seal positioning member having the body extending therethrough;    an elastomeric seal secured below the seal positioning member for receiving the angled camming surface; and    means for selectively moving the body upward forcing the angled camming surface into engagement with the elastomeric seal thereby forcing the elastomeric seal outwardly from the body and into sealing engagement with the surrounding surface.    
   
   
       12 . The packoff assembly according to  claim 11  further characterized by a hub for threadedly engaging the upper end of the body for effecting upward movement of the body into engagement with the elastomeric seal.  
   
   
       13 . The packoff assembly according to  claim 12  wherein a shim is inserted between the hub and the seal positioning member to maintain the elastomeric seal in sealing engagement with the surrounding surface.