FIELD: mechanical engineering.
SUBSTANCE: plastic bolt disposed above area to be punched in closed vessel has lower part in form of tongue with cylindrical drain-out neck, connected or to be connected with vessel, and screw cap which is screwed on lower part. It also has cylindrical punch which is open at both sides at axial direction and is installed in lower part for movement. There are aids in screw cap for shifting punch along screw-type manner down when screw cap is screwed out the first time. Punch is provided with at least two cutting tools disposed one behind the other at some distance for angle of sift of 100-180° in such a way that after punch turns by angle of shift, the unite line of cutting forms. In non-cut area the substituting element is in effect, which element shifts partially cut-out piece of vessel out of drain-out area.
EFFECT: ease at opening.
8 cl, 6 dwg
