Patent ID: 6340261
Filing Date: 2002-01-22
Classification: B43K

Abstract:
A clicking-type ball-point pen having a front opening from which a writing portion can be protruded at a front end of a barrel cylinder, and a click bar serving as a protruding pushing portion at a rear end, whose ball rotatably fitted loosely in the state of protruding outside from the front end is restricted in the back and forth movement by a caulking portion at a front end and by a ball seat at a rear end, comprising:a point assembly having an ink hole for leading the ink from the rear end side; an ink storing tube for directly storing a medium viscosity ink whose ink viscosity at a normal temperature (23Â° C.) is in a range of from 10 cp to 5000 cp; a channel groove constituted by a plurality of grooves communicating the ball seat and the ink hole, which is not penetrated through in the longitudinal direction; and an elastic body installed in a state that it cannot be pulled out such that it pushes the ball at the point directly or indirectly via a movable member at all times; and accommodating a writing element serving as a writing body within the barrel cylinder, movably in the back and forth direction; wherein the following relation: 20Â·W75Â·W is satisfied between a projection area W (mm2) of a diameter of the writing ball and a pushing force P (g) of the elastic body; and wherein the writing element is constructed such that it is urged rearward at all times by a return spring; and the following relation: 50Â·RÂ·R+20Â·P) is satisfied among a ball pushing force P (g) within the point assembly and a pushing force S (g) of the return spring and a weight R (g) of the writing element.