Parallel-tapered-integrated screw-coupling structure for connecting reinforcing bars

A parallel-tapered-integrated screw-coupling structure, comprising:

• a female screw member including a parallel-tapered-integrated female threaded-portion at which a parallel female threaded-portion composed of parallel threads is formed on an inner surface thereof and a tapered female threaded-portion of which a minor diameter decreases is integrally formed at an end of the parallel female threaded-portion;
• and
• a male screw member including a parallel-tapered-integrated male threaded-portion at which a parallel male threaded-portion composed of parallel threads is formed on an outer surface thereof, and a tapered male threaded-portion of which a major diameter decreases is integrally formed at an end of the parallel male threaded-portion,
• wherein the male screw member is a solid male screw member for threaded connection, the male screw member including a shank and threads formed around a circumferential surface of the shank,
• wherein
• a minor diameter of the parallel female threaded-portion is larger than a maximum minor diameter of the tapered female threaded-portion,
• a major diameter of the parallel male threaded-portion is larger than a maximum major diameter of the tapered male threaded-portion,
• a thread-discontinuous portion is formed between the parallel female threaded-portion and the tapered female threaded-portion and between the parallel male threaded-portion and the tapered male threaded-portion, and
• the minor diameter of the parallel female threaded-portion is larger than the maximum major diameter of the tapered male threaded-portion,
• wherein
• the male screw member or the female screw member are integrated with a reinforcing bar, such that
• the male screw member or the female screw member is integrated at an end of the reinforcing bar, or
• the male screw member is integrated at both ends of the reinforcing bar, or
• the female screw member is integrated at both ends of the reinforcing bar, or
• the male screw member and the female screw member are integrated at both ends of the reinforcing bar, respectively,
• wherein,
• at a temporary-coupled state of the female and male screw members,
• the female and male tapered threaded-portions are in mutual contact while the female and male parallel threaded-portions are mutually spaced apart, or
• the female and male tapered threaded-portions and the female and male parallel threaded-portions are all in simultaneous contact, or
• the female and male tapered threaded-portions are mutually spaced apart while the female and male parallel threaded-portions are in mutual contact,
• wherein,
• upon rotation in a screw-tightening direction,
• the tapered threaded-portions begin engagement before the parallel threaded-portions, or
• the tapered threaded-portions and the parallel threaded-portions begin engagement simultaneously, or
• the parallel threaded-portions begin engagement before the tapered threaded-portions,
• wherein the thread-discontinuous portion is a recess formed as an annular groove in the circumferential direction.