Abstract: A plug-in safety coupling for pressure pipes consists of a coupler box with a blocking member pivotally mounted therein. The latter has a diametrical through bore in which a plug can be inserted, in a depressurized state, at an acute to a right angle to the conducting position. The blocking member can be brought into the conducting position by pivoting the plug. A cupped locking sleeve shaving a hemispherical front end is placed over the coupler box with the pivoting member. This hemispherical front end comprises a spherically extending oblong hole that extends along a great circle on the hemispherical end from the center thereof. The locking sleeve is rotatably mounted on the coupler box and is biased by a spring to such an extent that its oblong hole extends with an offset by 90° relative to the pivoting plane of the blocking member of the plug. Only when the locking sleeve is pivoted, a plug can be inserted.

Abstract: In a rapid coupling, an end section of a pipe nipple engages in a throughhole of a sleeve. A groove provided on the pipe nipple serves to engage a resilient locking ring formed in the sleeve in order to lock the coupled state. The locking ring is located in an annular recess formed close to the insertion end of the sleeve. If the pipe nipple is not inserted into the bush to such an extent that the locking ring latches in the groove, the pipe nipple is pushed outward by a compression spring provided in the throughhole of the sleeve, so that the groove is readily visible outside the sleeve. The groove thus serves not only for locking in the properly coupled state but also as an indicator for indicating a state which is not properly coupled.

Abstract: A plug-in safety coupling for pressure pipes consists of a coupler box with a blocking member pivotally mounted therein. The latter has a diametrical through bore in which a plug can be inserted, in a depressurized state, at an acute to a right angle to the conducting position. The blocking member can be brought into the conducting position by pivoting the plug. A cupped locking sleeve shaving a hemispherical front end is placed over the coupler box with the pivoting member. This hemispherical front end comprises a spherically extending oblong hole that extends along a great circle on the hemispherical end from the center thereof. The locking sleeve is rotatably mounted on the coupler box and is biased by a spring to such an extent that its oblong hole extends with an offset by 90° relative to the pivoting plane of the blocking member of the plug. Only when the locking sleeve is pivoted, a plug can be inserted.

Abstract: In a rapid coupling, an end section of a pipe nipple engages in a through-hole of a sleeve. A groove provided on the pipe nipple serves to engage a resilient locking ring formed in the sleeve in order to lock the coupled state. The locking ring is located in an annular recess formed close to the insertion end of the sleeve. If the pipe nipple is not inserted into the bush to such an extent that the locking ring latches in the groove, the pipe nipple is pushed outward by a compression spring provided in the through-hole of the sleeve, so that the groove is readily visible outside the sleeve. The groove thus serves not only for locking in the properly coupled state but also as an indicator for indicating a state which is not properly coupled.