Ballpoint tip for ballpoint liquid container

摘要

A ballpoint tip for a ballpoint liquid container, such as a ballpoint refill, includes a tubular body member, a ball held for rotation in a tip part of the tubular body member, and a coil spring extended in the tubular body member to press the ball against the inner surface of the tip part of the tubular body member. The coil spring is formed by coiling a spring wire, a forward end part of the spring wire is extended linearly to form a straight forward end part, and a back end part of the spring wire is coiled in end coils of an outside diameter greater than that of the effective coils of the coil spring to form a large base end. The coil spring is extended with the base end thereof held in the caulked back end part of the tubular body member and the straight forward end part extended through a liquid passage and in contact with the ball. The coil spring can be strained by applying a pressure thereto through the ball.