Abstract: The invention relates to a breech for a repeating rifle with a lock guide, a bolt head arranged in the lock guide, a locking sleeve arranged concentrically with the bolt head with several locking elements that can be moved by an expansion device between an inner unlocked position and an outer locked position, and a locking lever that is arranged in the lock guide and that can be activated by means of a bolt handle with which is associated a first cam element that is arranged so that it can rotate in the lock guide with a rear contact surface for support against a fixed control element. To allow especially smooth-running and safe locking action, a second cam element, which can rotate independently of the first cam element and that has a rear control cam for support against the fixed control element is associated with the locking lever.

Abstract: The invention relates to a breech for a repeating rifle with a lock guide, a bolt head arranged in the lock guide, a locking sleeve arranged concentrically with the bolt head with several locking elements that can be moved by an expansion device between an inner unlocked position and an outer locked position, and a locking lever that is arranged in the lock guide and that can be activated by means of a bolt handle with which is associated a first cam element that is arranged so that it can rotate in the lock guide with a rear contact surface for support against a fixed control element. To allow especially smooth-running and safe locking action, a second cam element, which can rotate independently of the first cam element and that has a rear control cam for support against the fixed control element is associated with the locking lever.

Abstract: The invention concerns an apparatus for forming annular circumferential corrugations in the end of a helically corrugated seamed pipe. Two corrugating rolls, a backup roll and a thrust roll, engage the wall of the pipe to form the annular corrugations. The backup roll normally engages the inner wall of the pipe, and the thrust roll, the outer wall. The thrust roll is formed from a plurality of independent and transversely movable roll sections urged with a predetermined force into engagement with the pipe by a support composed of a group of rolls engaging the periphery of a corresponding roll section and mounted within a pivotable lever frame. The predetermined force is provided by a pressure-controlled hydraulic cylinder acting through each of the lever frames.