Patent ID: 7596847
Filing Date: 2009-10-06
Classification: E21B,Y10T

Abstract:
1. A method of providing a sucker rod to coupler connection including: providing first and second sucker rods each having first and second spaced pin ends each with a predetermined pin end length within a selected longitudinal range of length tolerances and having a longitudinal sucker rod axis; providing each of said first and second spaced pin ends with a threaded pin end section having a first end and a second end; terminating each said threaded pin end section first end in a pin end flat face; providing each said pin end flat face extending transverse to said longitudinal sucker rod axis; providing a radial shoulder spaced longitudinally from each said threaded pin end section second end, each said radial shoulder extending radially out from each said pin end; providing a flat radial bearing face on each said radial shoulder and extending transverse to said longitudinal sucker rod axis and further being spaced from said threaded pin end section second end; providing an unthreaded pin neck between each said threaded pin end section second end and said flat radial bearing face on each said pin end; dimensioning each said sucker rod pin end for providing said pin neck having a predetermined longitudinal length between said flat radial bearing face and said threaded pin end flat face; providing a coupler having a predetermined coupler length within a selected longitudinal range of length tolerances and having first and second coupler ends with first and second coupler flat end faces and with a coupler center; preassembling said first coupler end with said first threaded pin end section of a first sucker rod to a hand tight engagement of said radial flat bearing face against said coupler first flat end face; turning said coupler relative to said first pin end past the hand-tight plane for accomplishing a specified length additional displacement of said first pin end into said coupler and thereby imparting a tensive pre-stress to said first pin neck; providing a torque washer having a threaded periphery, a predetermined torque washer axial length and first and second torque washer flat end faces spaced apart from each other in a direction of said torque washer axial length; threading said torque washer into said second coupler end and engaging said first pin flat end face with said torque washer first flat end face; inserting a second threaded pin end section of a second sucker rod into said second end of said coupler; tightening said second pin end of said second sucker rod into said coupler with a predetermined linear displacement of said second pin end face into said coupler past an engagement position of a flat radial bearing surface of said second sucker rod second pin end against said coupler second end and imparting a tensive pre-stress to said second pin neck; engaging said second pin flat end face of said second sucker rod against said torque washer second flat end face; and compressing said pin ends of said first and second sucker rods against said first and second torque washer flat end faces and forming a compressive pre-stress in said torque washer and said first and second pin end threaded end sections adjacent said pin end faces and forming a tensive stress in said coupler center by properly selecting said predetermined pin end lengths, torque washer length and coupler length.