Tubular connection with slotted threads

Abstract

A connection for the quick and functionally reliable connection of tubulars including pipes and casing. The connection having a male or pin end and a mating female, box, or socket end and sections of circumferentially and axially extending protuberances such as thread segments or lugs interrupted by slots extending circumferentially and axially approximately the same distance as the corresponding protuberance section and can have at least on continuous, uninterrupted thread for a landing surface. Both the pin and box have matching or corresponding arrays of interrupted threads and slots. When properly aligned, the array will be accepted by a corresponding slot when mating the pin and box. After proper mating, the connection is secured by rotating the pin or box to further mate the corresponding patches of the pin and box.

1 . A connection for assembly of pipe, the connection comprising: 
 a first pipe having a female end;    a second pipe having a male end;    said female end having an inner surface and an outer surface;    said male end having an inner surface and an outer surface;    a first plurality of protuberances circumferentially and longitudinally spaced relative to each other about the inner surface of said female end;    a second plurality of protuberances circumferentially and longitudinally spaced relative to each other about the outer surface of said male end;    wherein said circumferential spacing forms a circumferential array comprising at least one longitudinal column on both the inner surface of said female end and the outer surface of said male end;    said plurality of circumferential arrays aligned such that said plurality of protuberances are accepted by a mating pipe end when said male and female pipe ends move longitudinally relative to each other for forming a connection; and    wherein the male and female ends engage upon any rotation of one pipe relative to the other pipe wherein such rotation causes said protuberances of the male end and said protuberances of the female end to move circumferentially with respect to each other.    
   
   
       2 . The connection according to  claim 1 , wherein said plurality of arrays comprises an odd number of said arrays.  
   
   
       3 . The connection according to  claim 1 , wherein at least some of said protuberances are shaped to be radially captured to prevent radial expansion of the female end relative to the male end.  
   
   
       4 . The connection according to  claim 1 , wherein at least one of said protuberances embodies at least one interference dimension that causes one surface to displace a mating surface.  
   
   
       5 . The connection of  claim 1 , wherein at least some of the protuberances have a crest and a root and wherein radial interference exists between the crest and root of at least one mating protuberance, said interference increasing with the relative rotation between the male and female ends.  
   
   
       6 . The connection according to  claim 1 , wherein one wrap of said at least one screw thread on at least one of said first and second pipe ends is not interrupted by said slots, to provide a landing surface for said pipe ends when they are moved longitudinally into engagement.  
   
   
       7 . The connection according to  claim 1 , further comprising a first alignment indicator on said male end and a second alignment indicator on said female end wherein said indicators being positioned to correspond with the circumferential point that marks the start of an array of protuberances such that when said indicators are aligned prior to said rotation of one pipe relative to the other pipe, said indicators will provide visual indication of the amount of rotation.  
   
   
       8 . The connection according to  claim 1 , wherein a locking element preventing loosening extends through a wall of the female end to project into the path at least one protuberance would traverse if the connection were to loosen.  
   
   
       9 . A method of making a connection comprising: 
 providing a first pipe having at least one female end, said female end having an inner surface and an outer surface;    providing a second pipe having a at least one male end, said male end having an inner surface and an outer surface;    providing a first plurality of protuberances circumferentially and longitudinally spaced relative to each other about the inner surface of said female end;    providing a second plurality of protuberances circumferentially and longitudinally spaced relative to each other about the outer surface of said male end;    wherein said circumferential spacing forms a circumferential array comprising at least one longitudinal column on both the inner surface of said female end and the outer surface of said male end;    aligning said first pipe and said second pipe such that the female end of said first pipe is aligned to receive the male end of said second pipe;    further aligning said first pipe and said second pipe wherein said plurality of circumferential arrays are aligned such that said first plurality of protuberances, are accepted by a mating pipe end when the pipe ends move longitudinally relative to each other for forming a connection;    providing longitudinal movement wherein said male end will enter and mate with said female end;    continuing longitudinal movement until said male end is fully engaged in said female end; and    rotating one pipe with respect to the other pipe wherein said rotation causes the protuberances of the male and female ends to move circumferentially with respect to each other and wherein the male and female ends engage each other.    
   
   
       10 . The method of  claim 9 , wherein the rotation of one pipe segment with respect to the other pipe segment is less than 20 degrees.  
   
   
       11 . The method of  claim 9 , further comprising the steps of providing a first alignment indicator on said male end and a second alignment indicator on said female end wherein said indicators being positioned to correspond with the circumferential point that marks the start of the circumferential array of protuberances such that when said indicators are aligned prior to said rotation of one pipe relative to the other pipe, said indicators will provide visual indication of the amount of rotation.  
   
   
       12 . A threaded connection for end-to-end assembly of pipe sections to pipe strings, the connection comprising: 
 a first pipe end with a socket and a second pipe end with a pin to mate with said socket;    a plurality of first cam patches of first arcuate cams extending peripherally about the inner surface of said socket, said first cam patches separated by surfaces defining peripherally extending first slots;    a plurality of second cam patches of second arcuate cams extending peripherally about the outer surface of said pin, said second cam patches separated by surfaces defining peripherally extending second slots;    all said slots and patches arranged such that said patches are accepted by said slots when said pin end is axially inserted into said socket;    all said arcuate cams axially distributed some distance and comprising lands and grooves peripherally extending some distance in a selected helical direction, said grooves configured to accept said lands when rotation of said box relative to said pin causes said lands to move peripherally along said grooves; and    at least one first abutting surface on said first pipe arranged to oppose and mate with a second abutting surface on said second pipe, with a selected axial force, when said patches on said pin are approximately juxtaposed with said patches on said socket.    
   
   
       13 . The connection according to  claim 12 , wherein at least some of said lands and their related said grooves are shaped to radially capture said lands within its related said grooves to prevent radial expansion of said socket relative to said pin.  
   
   
       14 . The connection according to  claim 12 , wherein at least one of said arcuate cams embodies at least one interference dimension that causes one surface to displace a mating surface, by material strain, to increase the torque required to rotate said first pipe relative to said second pipe.  
   
   
       15 . The connection according to  claim 12 , wherein one wrap of said at least one screw thread on at least one of said first and second pipe ends is not interrupted by said slots, to provide a landing surface for said pipe ends when they are moved axially into engagement.  
   
   
       16 . The connection according to  claim 12 , wherein at least some of said lands and grooves have dimensional relationships such that an interference resists rotation of said socket relative to said pin, said interference requiring expansion of said socket for the connection to be completed.  
   
   
       17 . The connection according to  claim 12 , wherein a locking element extends through a wall of the socket to project into the path at least one arcuate cam would traverse if the connection were to loosen, to prevent such loosening.  
   
   
       18 . A threaded connection for end-to-end assembly of pipe sections, the connection comprising: 
 first and second pipe ends to be threadedly joined, said first pipe having female configuration defined as a box, the second pipe having mating male configurations defined as a pin;    the box having, in series, a first abutment surface defining one end of the first pipe, a first unthreaded length, a first threaded length, a second unthreaded length, and a second abutment surface to terminate the box configuration on the first pipe;    the pin having, in series, a third abutment surface to mate said second abutment surface, a third unthreaded length to be received in the second unthreaded length, a second threaded length to mate with the first threaded length, a fourth unthreaded length to be received in the first unthreaded length, and a fourth abutment surface to mate with the first abutment surface and terminate the pin configuration;    the first and second threaded lengths, each, comprising at least two patches of incomplete threads on the pin and similar and mating patches of incomplete threads in the box, all said patches formed by peripheral thread cut-outs producing surfaces to define slots which will accept the patches when the box receives the pin in axial relative movement, the patches on the pin arranged to engage the patches in the box when the pin is rotated relative to the box, said abutting surfaces to be axially force loaded a preselected amount when the patches on the pin are approximately juxtaposed with the patches on the box.    
   
   
       19 . The threaded connection of  claim 18 , wherein radial interference exists between the crest and root of at least one mating thread, said interference increasing, within selected limits, with the relative tightening rotation between the pin and the box.  
   
   
       20 . The threaded connection of  claim 19 , wherein said interference increases until a selected amount of relative rotation of the box and pin is achieved, then said interference is reduced for the remaining amount of the tightening relative rotation.