| 摘要 |
A PIPE JOINT, COMPRISES A SCREW-THREADED JOINT FOR PIPES COMPRISES A PIN (10) HAVING A MALE SCREW-THREADED PORTION (15) AND A BOX (20) HAVING A COMPLEMENTARY SCREW-THREADED PORTION (25). THE THREADED PORTIONS OF THE PIN AND BOX (10, 20) INTER-ENGAGE ALONG THE GREATER PART OF THE AXIAL LENGTH OF THE THREADED PORTIONS, THE MALE THREAD EXTENDING TO A MALE STOP SHOULDER ADJACENT A COMPLEMENTARY STOP SHOULDER ON THE OTHER PORTION. THE PIN (10) FURTHER COMPRISES A RADIAL SURFACE (12) ADJACENT A CORRESPONDING RADIAL SURFACE (22) ON THE COMPLEMENTARY STOP SHOULDER OF THE BOX, A CURVED SEALING SURFACE (14) OF THE RADIAL SURFACE ON THE PIN SEALINGLY ENGAGING A CORRESPONDING CURVED SEALING SURFACE (24) ON THE CORRESPONDING RADIAL SURFACE ON THE COMPLEMENTARY STOP SHOULDER. EACH OF THE CURVED SEALING SURFACES (14, 24) IS SO SHAPED TO LIE ON AN ARC OF A SEPARATE ELLIPSE. THE PARAMETERS OF THE ELLIPSES ARE CAREFULLY CHOSEN TO MAXIMIZE THE STRENGTH AND ROBUSTNESS OF THE SEAL. |
