JP2006231833A - Ball-point pen tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball-point pen tip equipped with both ink-following property and write-starting property. <P>SOLUTION: In the ball-point pen tip which holds a ball in the ball holding chamber of the tip end in a freely rotatable manner and has an ink flowing hole communicating with the inner hole of the tip rear end part at the center of the bottom wall of the ball holding chamber, the ink flowing hole is formed in a substantially polygonal cross section and ink flowing grooves which radially extend from the ink flowing hole and do not reach the inner hole of the tip rear end part are formed on each side of the ink flowing hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ballpoint pen tip formed by holding a ball rotatably in a ball holding chamber at the tip of the tip.

  Conventionally, a ball-point pen tip having an ink circulation groove communicating with an ink circulation hole at the center of the bottom wall of the ball holding chamber is well known. With regard to such ball-point pen tips, Japanese Patent Publication No. 2000-516870 “Ball-point pen bearing tips” and Japanese Patent Publication No. 36-5423 “Method of manufacturing ball-point pens” disclose a structure in which the ink circulation holes have a polygonal cross section.

In addition, a type that communicates with the ink circulation hole and does not reach the inner hole at the rear end of the chip, such as Japanese Utility Model Laid-Open No. 7-31382 “ballpoint pen”, is well known.
"Special Table 2000-516870 Publication" "Japanese Patent Publication No. 36-5423" “Japanese Utility Model Publication No. 7-31382”

  The ink circulation groove that communicates with the former ink circulation hole and the inner hole at the rear end of the chip is excellent in ink following because the ink flows smoothly from the rear end of the chip. It is suitable as a ballpoint pen tip.

  The ink distribution groove that communicates with the latter ink distribution groove and does not reach the inner hole at the rear end of the chip is excellent in writing performance because ink accumulates in the ink distribution groove, and ink is placed on the ball by the rotation of the ball and discharged. Therefore, it is suitable as a ball-point pen tip for ink having a relatively high ink viscosity, such as an oil-based ballpoint pen and shear thinning ink.

  As a ballpoint pen tip that has both ink followability and writing ability, it communicates with the ink circulation hole and the inner hole at the rear end of the chip, and the inner hole at the rear end of the chip. It is conceivable that an ink circulation groove is not provided, but formation of the ink circulation hole, formation of the ink circulation groove communicating with the inner hole of the ink circulation hole and the rear end of the chip, and communication with the ink circulation groove, the rear end of the chip Since the ink distribution groove that does not reach the inner hole of the part and the centering work are required, there is a problem that the manufacturing process becomes complicated.

  An object of the present invention is to provide a ball-point pen tip that has both ink followability and writing ability with a simple structure.

  The present invention relates to a ball-point pen tip that holds a ball rotatably in a ball holding chamber at the tip end of the tip, and has an ink circulation hole in the center of the bottom wall of the ball holding chamber that communicates with an inner hole at the tip end of the tip. The ink circulation holes are formed in a polygonal cross section, and ink circulation grooves that extend radially from the ink circulation holes and do not reach the inner holes at the rear end of the chip are formed on each side of the ink circulation holes.

  The circumscribed circle diameter of the ink circulation hole and the ink circulation groove is a polygonal cross section larger than the ball diameter.

  The ink circulation groove has a polygonal cross section.

  The ink circulation groove has a polygonal cross section that is substantially the same shape as the ink circulation hole.

  Further, the diameter of the circumscribed circle of the ink circulation hole is a polygonal cross section larger than the ball diameter.

  We were able to provide a ball-point pen tip that has both ink followability and writing ability.

  Next, examples of the ball-point pen tip of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.

  The ball-point pen tip 1 shown in FIG. 1 and FIG. 2 has a ball 9 placed on the bottom wall 4 of the ball holding chamber 3 of the chip body 2 and the tip end edge 5 is caulked inward so that the ball 9 can be rotated. Is hugging. The bottom wall 4 of the ball holding chamber 3 is formed with an ink circulation hole 6 communicating with the inner hole 8 at the rear end of the chip and an ink circulation groove 7 extending radially from the ink circulation hole 6.

  The ink circulation hole 6 has a substantially equilateral triangular cross-sectional shape, and an ink circulation groove 7 that does not reach the inner hole 8 at the rear end of the chip is formed on each side 6a.

  By making the ink circulation holes 6 have a substantially equilateral triangular cross section, the ink flow passage area can be increased compared to the inscribed circle r1, and the ball can be stably held compared to the circumscribed circle R1. Further, the corner 6a of the ink circulation hole 6 becomes an ink circulation groove that communicates with the inner hole 8 at the rear end of the chip, and the ink circulation groove 7 that communicates with the ink circulation hole 6 and does not reach the inner hole 8 at the rear end of the chip. And the ballpoint pen tip 1 having two different kinds of distribution grooves 6a and 7 are obtained.

  The ball-point pen tip 11 shown in FIGS. 3 and 4 has the ball 9 placed on the bottom wall 14 of the ball holding chamber 13 at the tip end of the tip body 12 and the tip end edge 5 is caulked inward as in the first embodiment. As a result, the ball 9 is rotatably held. The bottom wall 14 of the ball holding chamber 13 is formed with an ink circulation hole 16 communicating with the inner hole 18 at the rear end of the chip and an ink circulation groove 17 extending radially from the ink circulation hole 16.

  The ink circulation hole 16 has a substantially equilateral triangular cross section, and an ink circulation groove 17 that does not reach the inner hole 18 at the rear end of the chip is formed on each side of the ink circulation hole 16 in a substantially equilateral triangular section that is the same shape as the ink circulation hole 16. It is.

  By making the ink circulation holes 16 have a substantially equilateral triangular cross section, the ink flow passage area can be increased as compared with the inscribed circle r2, and the ball can be stably held as compared with the circumscribed circle R2. In addition, the corner 16a of the ink circulation hole 16 becomes an ink circulation groove that communicates with the inner hole 18 at the rear end of the chip, and the ink circulation groove 17 that communicates with the ink circulation hole 16 and does not reach the inner hole 18 at the rear end of the chip. And the ballpoint pen tip 11 having two different kinds of distribution grooves 16a and 17 are obtained.

  By making the ink circulation holes 16 and the ink circulation grooves 17 the same shape, it is only necessary to increase or decrease the stroke to be driven in the manufacturing process, so that the production tools for the ink circulation holes 16 and the ink circulation grooves 17 can be made the same shape. Therefore, it becomes easy to design tools and manage exchange inventory.

  In the present embodiment, for convenience, the ink circulation holes have a substantially regular triangular cross section, but may be a substantially triangular cross section such as a substantially triangular cross section, a substantially quadrangular cross section, a substantially pentagonal cross section, etc. This is preferable because the corners of the ink circulation holes and the ink circulation grooves are evenly positioned with respect to the ball.

  Although not shown, the circumscribed circles R1 and R2 of the ink circulation holes have a polygonal cross section larger than the ball diameter L (R1> L or R2> L), so that the ball is placed on the bottom wall. Therefore, it is preferable because the ink circulation hole is not completely closed with a ball. Moreover, in order to increase an ink flow path area, you may form roundness in the corner | angular part of an ink distribution groove | channel.

  It can be carried out without being limited to the type of ink and ink viscosity, such as oil-based ink, shear thinning ink, and water-based ink.

It is the longitudinal cross-sectional view which abbreviate | omitted partially which shows the ball-point pen tip of Example 1. FIG. It is the top view which abbreviate | omitted the ball | bowl of the arrow A direction in FIG. It is the longitudinal cross-sectional view which abbreviate | omitted partially which shows the ball-point pen tip of Example 2. FIG. It is the top view which abbreviate | omitted the ball | bowl of the arrow B direction in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Ball-point pen tip 2, 12 Tip body 3, 13 Ball holding chamber 4, 14 Bottom wall 5, 15 Tip tip 6, 16 Ink flow hole 7, 17 Ink flow groove 8 ball

Claims (4)

In the ball-point pen tip which holds the ball rotatably in the ball holding chamber at the tip of the chip and has an ink circulation hole in the center of the bottom wall of the ball holding chamber and which communicates with the inner hole of the rear end of the tip. The flow hole is formed in a substantially polygonal cross section, and an ink flow groove that extends radially from the ink flow hole and does not reach the inner hole at the rear end of the chip is formed on each side of the ink flow hole. Ballpoint pen tip. The ball-point pen tip according to claim 1, wherein the ink circulation groove has a polygonal cross section. The ballpoint pen tip according to claim 2, wherein the ink circulation groove has a polygonal cross section substantially the same shape as the ink circulation hole. 4. The ballpoint pen tip according to claim 1, wherein a diameter of a circumscribed circle of the ink circulation hole is a polygonal cross section larger than a ball diameter.

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