Screw cover pliers for vacuum bottle - have protrusions curved more sharply than cover to form dents foe breaking vacuum (NL 30.3.79)

摘要

The screw-cover pliers have two arms each with protrusions forming jaws on each side, engaging with the cover periphery. The protrusions on one side are spaced further apart than on the other, and the arms hinge together between the jaw portion and the hand grip. There are four protrusions on each arm side, two (5b, 5c) being on the front part and two (5a, 5d) on the rear. Those on one side are on the inside of the arm and those on the other on the outside, and they are curved more sharply in the peripheral direction than the smallest cover to be manipulated.