Abstract: A device and method for forming an annular raised rib on a tubular member includes a mandrel having a primary portion which has a secondary portion slidably mounted on the outer end thereof. The inner end of the primary mandrel carried by a base. An expandle ring is carried by the secondary mandrel and the outer end of the primary mandrel. Further included is a movable die with means for moving the die to and upon the primary mandrel. The secondary mandrel is formed with an annular frusto-conical ramp for expanding the ring radially outwardly thereof which forces the wall of the tubular member outwardly thereby forming an annular raised rib on a tube of plastic mounted on the mandrels when the secondary mandrel is moved to and upon the primary mandrel.

Abstract: A device and method for forming an annular raised rib on a tubular member includes a mandrel having a primary portion which has a secondary portion slidably mounted on the outer end thereof. The inner end of the primary mandrel carried by a base. An expandle ring is carried by the secondary mandrel and the outer end of the primary mandrel. Further included is a movable die with means for moving the die to and upon the primary mandrel. The secondary mandrel is formed with an annular frusto-conical ramp for expanding the ring radially outwardly thereof which forces the wall of the tubular member outwardly thereby forming an annular raised rib on a tube of plastic mounted on the mandrels when the secondary mandrel is moved to and upon the primary mandrel.