| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that an ink housing cylinder having a structure wherein a float is immersed in a viscous material to seal ink can correspond to instantaneous impact resistance but, when the pen point of a writing utensil is allowed to stand continuously in an upwardly turned state, the viscous material present between the inner surface of the ink housing cylinder and the outer surface of the float flows backward in the rear end direction opposite to the pen point by small quantity and the before and behind positional relation of the viscous material and float in the ink housing cylinder is reversed and this phenomenon is marked when the apparent specific gravity of the float to the specific gravity of the viscous material is low. SOLUTION: The float molded from a thermoplastic resin material mixed with color pigment is immersed and arranged in the viscous material injected and housed in the terminal of the ink housed in the ink housing cylinder. |
