Patent attributes
A thread joint for transmitting percussive forces includes a male thread on a male member and a female thread on a female member. The male member includes a first portion including an outer surface having a maximum first outer cross section, a second portion having a second maximum outer dimension, and a third portion having the male thread formed thereon. The second portion is disposed axially between the first and third portions. The male thread includes a thread start and a thread end. The third portion terminates in an axially facing first end surface. The female member has a recess in which the female thread is formed, the female thread having a mouth defined by a ring-shaped second end surface. The recess includes a cylindrical inner surface disposed between the second end surface and the female thread. The inner surface faces the cylindrical center portion of the male member. The inner surface has a diameter at least as large as the second maximum outer cross-sectional dimension, and smaller than the first maximum cross section. A first imaginary cylinder constituting an axial extension of the inner surface intersects the first portion of the male member, and a second imaginary cylinder constituting an axial extension of an outermost surface of the female member extends outside of the first portion of the male member.
