| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball point pen which uses a low-viscosity ink and allows easy insertion of a spring in a tip and in a stable position, even in case burrs are generated due to cutting, at the forward end of a bar shaft part of the spring, and also allows an apex ball to come into close contact with the inner surface of a ball embracing part of the tip and thereby, smooth rotation of the apex ball during writing, and thus can exhibit a successful writing performance free from a writing thin spot. <P>SOLUTION: This ball point pen is structured in the way that the apex ball has its back surface set in contact with a receiving seat having an ink circulation hole and radial grooves formed in the outer edge part of the ink circulation hole, in an inner hole at the apex part of the tip, and the apex ball is embraced rotatably by the apex part of the tip. In addition, a contact ball which can be inserted through the ink circulation hole formed in the center of the receiving seat, is arranged in contact with the back surface of the apex ball. Further, the spring is inserted in the inner hole at the rear of the tip, the forward end of the bar shaft part presses the back surface of the apex ball through the contact ball, and the apex ball is brought into close contact with an inner edge of the ball embracing part of the tip, resulting in the interruption of an ink outflow. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
