JP2012091391A - Ballpoint pen tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint pen tip of a simple structure which has a ball seat, and is configured to supply a large amount of ink to a ball.SOLUTION: The ballpoint pen tip includes a tip body having an ink flowing hole formed in the center of the bottom wall of a ball holding chamber and a plurality of ink flowing grooves extending radially from the ink flowing hole and not reaching a rear hole, and is configured by inserting the ball into the bottom wall to caulk the leading end of the tip inward, and projecting a part of the ball from the leading end edge of the tip to hold the ball freely rotatably. The ink flowing hole includes communicating grooves which communicate with the ink flowing grooves and the rear hole, and are smaller in circumferential width than the ink flowing groove.

Description

  The present invention has an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and an ink circulation groove extending radially from the ink circulation hole in the chip body, and the ball is inserted into the bottom wall. Further, the present invention relates to a ballpoint pen tip that is configured such that a tip of a tip is caulked inward so that a part of a ball protrudes from the tip tip edge and is rotatably held.

  Conventionally, a ballpoint 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. In such a ball-point pen tip, as in Japanese Utility Model Laid-Open No. 6-53185, “Ball Pen”, an ink distribution groove extending radially from the ink distribution hole and reaching the inner hole at the rear end of the chip, As is well known, a type of ink circulation groove that extends radially from the ink circulation hole and does not reach the inner hole at the rear end of the chip is well known.

  In order to increase the amount of ink supplied to the ball, many proposals have been made for the size of the ink circulation hole and the size of the ink circulation groove, particularly the opening area, as disclosed in Japanese Patent Application Laid-Open No. 2001-205968, “Ball Pen Tip”. ing.

  Furthermore, in a conventional ballpoint pen tip, a ball seat substantially the same shape as the ball is provided on the bottom wall of the ball holding chamber as disclosed in Japanese Patent Application Laid-Open No. 2000-71672, “ballpoint tip”. Many ballpoint pen tips with improved performance have been proposed.

Japanese Utility Model Publication No. 6-53185 Japanese Utility Model Publication No. 7-31382 JP 2001-205968 A JP 2000-71672 A

  However, for the purpose of increasing the ink supply amount, as in Patent Document 3, etc., increasing the ink distribution groove opening area increases the ink supply amount to the ball, but smoothes the ink flow to the ink distribution groove. It is not something to be done.

  In addition, it is conceivable to increase the diameter of the ink circulation hole to make the ink flow to the ink circulation groove smooth, but there is a problem that a new problem occurs such as a reduction in the area of the ball seat.

  Patent Document 1 is preferable because ink is directly supplied to the ink distribution groove from the rear hole of the chip. However, since the addition to the tool is large during manufacture and the tool life is short, there is a problem in Patent Document 2. Thus, the manufacturing cost can be reduced in the case of the ink distribution groove of the type that does not reach the rear end hole of the chip.

  The present invention has been made in view of these prior arts, and it is an object of the present invention to provide a ballpoint pen tip having a ball seat with a simple structure and a large amount of ink supplied to the ball.

  The present invention has, on the chip body, an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and a plurality of ink circulation grooves extending radially from the ink circulation hole and not reaching the rear hole, In a ball-point pen tip in which a ball is inserted into the bottom wall and a tip portion of the tip is caulked inward so that a part of the ball protrudes from the tip tip edge and is rotatably held. In addition, a through groove having a smaller width in the circumferential direction than the ink circulation groove, which communicates with the ink circulation groove and the rear hole, is provided.

  Further, the circumferential width of the ink circulation groove is gradually reduced toward the rear.

  According to the configuration of claim 1 of the present invention, the ink circulation hole is provided with a passage groove having a width smaller than that of the ink circulation groove and communicating with the ink circulation groove and the rear hole. Can be smoothly supplied from the rear hole to the ink circulation groove through the ink circulation hole and the passage groove.

  Further, since the through groove has a smaller width in the circumferential direction than the ink circulation groove, it is possible to easily supply ink from the rear hole to the through groove by the action of capillary action. .

  According to the configuration of claim 2 of the present invention, since the circumferential width of the ink circulation groove is gradually reduced toward the rear, the strength of the chip body is reduced by forming the ink circulation groove. Compared with the ink circulation groove of the same volume, the opening area on the bottom wall side of the ball-point pen tip can be increased and the ink for ball-point pen can be easily supplied.

  The ballpoint pen tip of the present invention is most preferably made of a metal such as stainless steel, aluminum, brass or the like.

  Further, the number and size of the ink circulation grooves are not particularly limited. Moreover, since the ink distribution groove has a shape that does not reach the rear hole, the life of the processing tool and high writing pressure performance can be improved.

  According to the present invention, a ball-point pen tip having a ball seat can provide a ball-point pen tip having a large ink supply amount to the ball with a simple structure.

FIG. 3 is an enlarged vertical cross-sectional view of a main part in which a part of the ball-point pen tip of Example 1 is omitted. It is a figure which shows the state before ball seat formation in FIG. It is AA sectional drawing which abbreviate | omitted the ball | bowl in FIG. It is a figure which shows the ball-point pen refill using the ball-point pen tip of Example 1. FIG.

  The ball-point pen tip 1 of Example 1 shown in FIGS. 1 to 3 includes an ink circulation hole 7 in the center of a ball holding chamber 3 of a chip body 2 made of a stainless steel wire, and extends radially from the ink circulation hole 7. A ball 10 made of tungsten carbide having a diameter of 0.7 mm is placed on the bottom wall 4 in which the ink circulation groove 6 that does not reach the rear hole 9 is placed, and the tip end 2a is caulked inward so that a part of the ball 10 is formed. Hold it rotatably so that it protrudes from the tip edge.

  The ballpoint pen tip 1 is a stainless steel wire having a diameter of 2.3 mm and a hardness of 230 Hv to 280 Hv. The ball holding chamber 3, the ink circulation holes 7, and the ink circulation grooves extending radially from the ink circulation holes 7 are cut. After producing 6, ball seats 5 having substantially the same shape as the balls 10 are formed on the bottom wall 4 of the ball holding chamber.

  Four ink circulation grooves 6 are formed radially from the ink circulation holes 7 at appropriate intervals. Further, the ink circulation hole 7 is provided with a through groove 8 communicating with the ink circulation groove 6 and the rear hole 9, and the width of the ink circulation groove 6 in the circumferential direction is from the width L of the opening to the ink circulation groove 6. The width M is gradually reduced toward the rear side toward the width M on the rear hole side. Further, the width J in the circumferential direction of the through groove 8 is made smaller than the width M on the rear hole 8 side of the ink circulation groove 6. Further, the radial depth K of the through groove 8 is shallower than the radial depth N of the ink circulation groove.

  FIG. 4 shows an example in which the ballpoint pen tip 1 of the present invention is used as the ballpoint pen refill 11. Specifically, the ball-point pen tip 1 of Example 1 is attached to the tip of the ink containing cylinder 12. A water-based ballpoint pen ink 14 imparted with shear thinning viscosity and a grease-like ink follower 15 are accommodated in the ink storage cylinder 12.

  When writing on the paper surface using this ball-point pen refill 11, the ball-point pen ink 14 in the ink containing cylinder 12 passes from the rear hole 9 of the ball-point pen chip 1 to the ink flow hole 7, the through groove 8, and the ink flow groove 6 to form the ball 10 and the ball holder. It is supplied to the holding room 3. The ball-point pen ink 14 supplied to the ball 10 and the ball holding chamber 3 has a gap between the ball 10 and the inner wall of the tip portion of the chip body 2 against the pressing force of the coil spring 13 that presses the ball 10 by the writing pressure. Can be written out from the gap on the paper surface.

  The flow of the ball-point pen ink 14 to the ink circulation groove 7 will be described in detail. The ink circulation groove 6 is reached from the rear hole 9 of the ball-point pen tip 1 through the ink circulation hole 7 and the passage groove 8. At this time, since the through groove 8 has a small circumferential width J and a radial depth K, the ink for the ballpoint pen is easy to flow by the capillary action, so that the ink circulation groove communicated with the through groove 8. 6 can smoothly supply the ball-point pen ink 14. Furthermore, by forming the through groove 8, it is not necessary to increase the diameter of the ink circulation hole 7, and the area of the ball seat 5 can be ensured.

  The through-groove 8 may be formed after the ink circulation hole 7 is formed in advance, or may be formed on the wall on the rear hole 9 side by forming the ink circulation groove 7 after forming the ink circulation groove 6. Alternatively, it may be formed simultaneously with the step of removing a built-up portion (not shown) protruding toward the ink circulation hole 7 side.

  The ink circulation hole diameter is not particularly limited, and can be appropriately selected according to the ink viscosity and the ink consumption, but is preferably 40% to 60% of the ball diameter. Further, the area of the ball seat is not particularly limited, and it is preferably 10 to 20% of the ball surface area in consideration of writing quality and wear resistance.

  The ballpoint pen tip of the present invention can be used without being limited to the ink used, and can be used regardless of the type of ink, such as oil-based ballpoint pen ink, water-based ballpoint pen ink, ink with shear thinning viscosity, and correction ink. Therefore, it can be widely used as a ball-point pen tip using a ball as a writing medium, and can be effectively used for a ball-point pen tip using water-based ink that causes capillary action.

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip body 2a Tip part 3 Ball holding chamber 4 Bottom wall 5 Ball seat 6 Ink flow groove 7 Ink flow hole 8 Through groove 9 Rear hole 10 Ball L, M The circumferential width of the ink flow groove J Through groove Width in the circumferential direction

Claims (2)

The chip body has an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and a plurality of ink circulation grooves extending radially from the ink circulation hole and not reaching the rear hole. In a ball-point pen tip in which a ball is inserted and the tip end of the tip is caulked inward so that a part of the ball protrudes from the tip end edge and is rotatably held. A ballpoint pen tip having a through groove that communicates with the groove and the rear hole and has a smaller width in the circumferential direction than the ink circulation groove. The ballpoint pen tip according to claim 1, wherein the circumferential width of the ink circulation groove is gradually reduced toward the rear.

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