公开(公告)号：US07416374B2

公开(公告)日：2008-08-26

申请号：US10543679

申请日：2004-01-29

申请人： James W. Breihan ,  Andrei M. Muradov

发明人： James W. Breihan ,  Andrei M. Muradov

IPC分类号： F16L25/00

CPC分类号： F16B33/02 ,  E21B17/042

摘要： A thread form having improved strength and fatigue resistance. The root of the thread is cut on multiple cutting radii having displaced centers. At least two of the root surfaces are formed by cutting radii having lengths that are greater than the root truncation. The threads are used in a double start configuration to increase the connection strength and reduce makeup and breakout rotations.

摘要翻译： 具有改善的强度和耐疲劳性的螺纹形式。 螺纹的根部在具有移位中心的多个切割半径上被切割。 至少两个根表面通过具有大于根截断长度的切割半径形成。 螺纹用于双重启动配置，以增加连接强度并减少化妆和突破旋转。