Coaxial coupling with by-pass valve and coupling mechanism with bayonette form

A coaxial coupling comprising a male part (501) and a female part (502), the male part (501) can be fitted into the female part (502), the coaxial coupling comprises a bypass valve (218) so that the female part (502) can be decoupled from the male part (501) while pressurized fluid passes through the female part (502), such as incoming fluid and return fluid, an inner pipe (2) of the female part (502) for pressurized fluid comprises at least one front hole (300) and one rear hole (301), which holes are arranged for said bypass valve (219);

• the inner pipe (2) and an outer pipe body (204) of the female part (502) are guided for coupling into a nipple pipe (105) and a nipple pipe body (104) of the male part (501), wherein the nipple pipe (105) of the male part (501) pushes a spring-loaded valve (218) in the female part (502) over said rear hole(s) (301), so that pressurized fluid is introduced into the nipple pipe (105) of the male part (501), characterized in that the female part (502) has a rotatable locking sleeve (207), which is coupled to a sleeve (214) accommodating pins (213) rotatable about the center axis of the female part (502), in that the nipple pipe body (104) of the male part (501) has helical grooves (100), wherein, upon said coupling and rotation of the locking sleeve (207), the pins (213), through rotation of the pins (213), when they fall into the grooves (100), catch in the walls of the grooves (100) and cause the nipple pipe body (104) of the male part to be pulled into the female part (502), while, when the male part (501) and the female part (502) are coupled together and the locking sleeve (207) is begun to be rotated, one end of the inner pipe (2) of the female part (502) simultaneously meets a relief valve (113) of the male part (501) and opens the relief valve (113), and pressurized oil is discharged against the valve of the female part (502) prior to continued opening of valves (115, 122) in the nipple pipe body (104).