Connection Assembly For Drill Collars or Heavy Drill Pipes

Connection assembly (100) for drill collars or heavyweight drill pipes, comprising:

• a male connecting element (300) having a substantially circular section about a longitudinal axis and that includes within its longitudinal direction, respectively:
• a substantially cylindrical first portion (302) forming a shoulder (301) at one of its ends,
• an at least partly threaded second conical surface portion (310) tapering from the first portion toward the free end of the element,
• a substantially cylindrical female connecting element (200), complementary to said male connecting element, including:
• a radial portion (201) forming a bearing face for said shoulder (301) of the first element and, longitudinally, coaxially and respectively, from that portion,
• an at least partially threaded conical interior surface complementary to the at least partially threaded conical surface of the male element,
• a cylindrical interior surface,
• said two connecting elements being intended to be assembled one into the other by a screwing action entailing several turns of the threads, characterized in that the male connecting element further includes, between said second portion and its free end, a third surface portion of lower taper than the second portion of the conical surface and sized relative to said cylindrical interior surface so that there exists a gap whereby these two surfaces come respectively into bearing contact if the assembly is stressed in bending.