Centroidally Twistable Compression Ring for Pipe Joints

Abstract

A locking ring designed to work in a self restraining pipe joint. This locking ring is designed (which may include attention to a combination of shape and material properties) to twist when exposed to a concentrated load and thereby distribute this load across broader area of the pipe joint to increase the thrust restraining capabilities of the joint

1 . A locking ring for use in restraining a pipe joint between a first pipe and a second pipe, said locking ring comprising a substantially ring-shaped body, that 
 a. is in a resting shape that is maintained in the joint during the absence of a force tending to separate the joint, and    b. is adapted to twist, in a manner such that a first location along the body rotates to a greater degree than a second location along the body rotates, in response to said force when an axis of the first pipe is displaced radially or angularly from an axis of the second pipe.    
   
   
       2 . A locking ring as in  claim 1 , wherein the resting shape is not twisted.  
   
   
       3 . A locking ring as in  claim 1 , wherein in the resting shape a radially inner surface of the locking ring is substantially parallel to the second pipe, and wherein after twisting at least a portion of the radially inner surface is off-parallel with respect to the second pipe by an angle that varies along the locking ring.  
   
   
       4 . A locking ring as in  claim 3 , wherein the radially inner surface is substantially flat.  
   
   
       5 . A locking ring as in  claim 1 , comprising 
 a. a radially inner surface adapted to be placed in contact with the second pipe,    b. a ring thrust surface adapted to contact a bell thrust surface located within a bell groove of the first pipe wherein an angle between the ring thrust surface and the radially inner surface is between 45 degrees and 80 degrees.    
   
   
       6 . A locking ring as in  claim 1 , comprising 65-45-12 ductile iron.  
   
   
       7 . A locking ring as in  claim 1 , comprising a cross section substantially as shown in  FIG. 2 .  
   
   
       8 . A locking ring as in  claim 1 , which is devoid of teeth capable of substantially biting into a pipe spigot of the second pipe.  
   
   
       9 . A locking ring as in  claim 1  wherein by said twisting the locking ring is adapted to bridge a gap of varying magnitude between a bell thrust face of the first pipe and a weld bead on a pipe spigot of the second pipe.  
   
   
       10 . A locking ring for use in restraining a pipe joint between a first pipe and a second pipe, said locking ring comprising a substantially ring-shaped body with longitudinal length, wherein the locking ring is adapted to change the longitudinal length by twisting in a manner such that a first location along the body rotates to a greater degree than a second location along the body.  
   
   
       11 . A locking ring as in  claim 10  wherein said change in axial length varies in magnitude between a first location on the locking ring and a second location on the locking ring.  
   
   
       12 . A locking ring as in  claim 10  wherein by said twisting the locking ring bridges a gap of varying magnitude between a bell thrust face of the first pipe and a weld bead on a pipe spigot of the second pipe.  
   
   
       13 . A locking ring as in  claim 10 , wherein in a resting state the locking ring is not twisted.  
   
   
       14 . A locking ring as in  claim 10 , wherein in a resting state the locking ring possesses a radially inner surface that adapted to be substantially parallel to the second pipe, and wherein after twisting at least a portion of the radially inner surface is off-parallel with respect to the second pipe by an angle that varies along the locking ring.  
   
   
       15 . A locking ring as in  claim 10 , comprising a radially inner surface that is substantially flat.  
   
   
       16 . A locking ring as in  claim 10 , comprising 
 a. a radially inward surface adapted to be placed in contact with the second pipe,    b. a ring thrust surface adapted to contact a bell thrust surface located within a bell groove of the first pipe    wherein an angle between the ring thrust surface and the radially inward surface is between 45 degrees and 80 degrees.    
   
   
       17 . A locking ring as in  claim 10 , comprising 65-45-12 ductile iron.  
   
   
       18 . A locking ring as in  claim 10 , comprising a cross section substantially as shown in  FIG. 2 .  
   
   
       19 . A locking ring as in  claim 10 , which is devoid of teeth capable of substantially biting into a pipe spigot of the second pipe.