Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
  • B43K—IMPLEMENTS FOR WRITING OR DRAWING
  • B43K1/00—Nibs; Writing-points
  • B43K1/08—Nibs; Writing-points with ball points; Balls or ball beds

Definitions

• the present invention relates to a ball point for writing instrument comprising:
• a tip body having a front face, said tip body comprising a housing which opens into an opening made in said front face and which communicates with a fluid supply passage;
• Ball points of the aforementioned type are used for writing instruments of the ball-point pen type, but also for writing instruments used to deposit a line of corrective fluid or glue on the paper.
• an accumulation of the fluid is obtained on the front face, and sometimes even on the lateral face of the tip body, which can cause soiling.
• the ink accumulated on the tip can also come off during the writing movement, which causes a burr to deposit on the paper.
• the modification of the ink generally has a damaging influence on the writing sensation perceived by the user and on the quality of the line written on the paper.
• the present invention aims to overcome the drawbacks mentioned above, by proposing a ball point offering perfect cleanliness of use, without deteriorating the feeling of sliding of the point on the paper or requiring an ink of particular composition. it is a ballpoint pen.
• an additional object of the invention is to avoid blocking of the ball after a prolonged period of non-use.
• the subject of the invention is a ball point of the aforementioned type in which the front face of the point body has a peripheral portion substantially parallel to the mean plane of the opening and a flared portion adjacent to the periphery of the opening. , which forms, at the point of contact of the ball with the periphery of the opening, an acute angle less than 70 degrees with the emerging part of the plane tangent to the ball at said point of contact.
• peripheral portion and the flared portion makes it possible to reduce in a completely unexpected proportion the burrs and the accumulation of ink on the tip.
• the tests carried out with ballpoint pens fitted with a tip according to the invention no longer show burrs, even using a greasy ink which has the advantage of providing a good feeling of sliding of the tip.
• the risk of ball blockage is greatly reduced.
• the angle formed by the flared portion and the emerging part of the plane tangent to the ball at the point of contact with the periphery of the opening is between 30 and 70 degrees, and preferably substantially equal to 45 degrees;
• the flared portion has an axial height h, measured in a direction perpendicular to the mean plane of the opening, between 0.6% and 5% of the diameter of the ball;
• the peripheral portion has a width 1, measured in a radial direction of the opening, of at least 0.01 millimeters and preferably between 1.2% and 5% of the diameter of the ball;
• the axial height h of the flared portion is substantially equal to the width 1_ of the peripheral portion;
• the opening of the tip body has a symmetry of revolution around a central axis;
• the flared portion is formed by a frustoconical surface coaxial with the central axis of the opening;
• the tip body is metallic, and the ball is retained in the housing by crimping the tip
• the subject of the invention is also: a ballpoint pen comprising a ball point as defined above in which the diameter of the ball is between 0.5 and 1.6 millimeters, and the ink has a viscosity greater than 40 poises; as well as a process for manufacturing such a ball point, from a rough point body having a front face and comprising a housing, a cylindrical front part of which opens into an opening formed on said front face, in which: a flared portion is produced by chamfering the periphery of the opening; . a ball, of diameter substantially equal to the diameter of the cylindrical front part of the housing, is inserted through one opening; the tip body has a front end which is crimped against the ball so as to retain the latter in the housing.
• FIG. 1 is a simplified view in longitudinal section of a existing ball point
• Figure 2 is a simplified view in longitudinal section of a ball point according to the invention
• FIG. 3 represents an enlarged view of the portion III of FIG. 2.
• the same references have been kept to designate identical or similar elements.
• FIG. 2 shows a ball point 1 for a writing instrument, and more particularly for a ball pen, comprising a point body 2.
• the left half-view of FIG. 2 represents a raw point body, while the right half-view represents the point body after mounting a ball 3.
• the point body 2 has a front face 4 and a shoulder 5 onto which an ink tank, not shown, can be fitted.
• the tip body 2 includes a housing 6 which opens into an opening 7 formed in the front face 4.
• the housing 6 opens into an opening 7 formed in the front face 4.
• the opening 7 has a symmetry of revolution about a central axis Z which coincides with the axis of symmetry of the tip body.
• a passage 8 for supplying a fluid ensures communication between the ink tank and the housing 6.
• the ball 3 is freely rotatably mounted in the housing 6 and emerges through the opening 7.
• the ball 3 is retained by a seat 9 formed at the bottom of the housing 6 and by the front end 10 of the wall of the point body 2 which follows the contour of the ball.
• the tip body 2 is metallic in the embodiment shown, which makes it possible to obtain the matching of the ball 3 by a crimping operation of the front end 10. Thus, the ball cannot make a movement of translation in the housing 6.
• the invention is also applicable to ball points comprising a spring arranged along the central axis Z which holds the ball against the front end 10 of the point body.
• the seat 9 may include channels or fins which improve the passage of the ink from the supply passage 8 to the space 17, located between the ball and the seat, in order to ensure a uniform deposition of the ink on the ball.
• the front face 4 of the tip body has a peripheral portion 11 and, on the periphery of the opening 7, a flared portion 12.
• the peripheral portion 11 extends towards the central axis Z from the outer periphery of the front face 4, to the flared portion 12.
• the peripheral portion 11 is substantially parallel to the mean plane of the opening 7, this is that is to say in the embodiment shown, substantially perpendicular to the central axis Z.
• the flared portion is arranged so as to form, at the point of contact 13 of the ball 3 with the periphery of the opening 7, an acute angle CL with the emerging part of the plane tangent to the ball at said contact point 13 and whose the trace T is visible in FIG. 2.
• peripheral portion 11 and the flared portion 12 makes it possible to significantly reduce the accumulation of ink on the front face 4, and the appearance of burrs on the paper.
• the inventors filmed at high magnification the rolling of the ball 3 on a paper-type surface.
• the films show a gradual accumulation of the ink at a point of contact 13 between the ball and the front face 4, which is located opposite to the direction of travel.
• the accumulation of ink ends up forming a drop 18, as shown diagrammatically in FIG. 3.
• this drop does not extend beyond the peripheral portion 11 and therefore, there is no ink deposit on the radially outer face of the tip body 2. It is also noted that the drop of does not detach from the front face 4 during a reversal of the direction of rotation of the ball, which explains the disappearance of the burrs. It is assumed that these phenomena are obtained by slightly drying the portion 18a of the drop, which is located towards the outside and therefore in contact with the air.
• the drop when it reaches a certain size, it collapses and almost disappears from the front face 4. This phenomenon can be explained by the presence of the flared portion 12 which forms with the wall of the ball 3 a funnel facilitating the return of the ink accumulated during the rotation of the ball.
• the portion 18b of the drop in contact with the ball 3 remains fluid due to the supply of fresh ink. The fluidity of the portion 18b certainly makes it possible to initiate the return of the ink.
• the ball point according to the invention therefore makes it possible to confine an accumulation of ink and then to ensure its return in the body of the point, and this contrary to the ball points of the prior art, such as that shown in the half view. right of figure 1.
• the opening 7 of these anterior points has a periphery 14 which forms an obtuse angle with the wall of the ball 3, which rather has the effect of scraping the ink present on the ball during its rotation and of retaining the accumulation ink formed on the front face 4.
• Such an accumulation of ink can then be deposited on the paper, in particular when the direction of rotation of the ball changes, and create a burr.
• the flared portion 12 is formed by a frustoconical surface coaxial with the central axis Z of the opening 7. This particular shape of the flared portion has the advantage of being able to be produced with great precision, in particular with the manufacturing process described below.
• the angle ce formed between the flared portion 12 and the emerging part of the tangent plane T is approximately 45 ° in the embodiment shown, but the flared portion 12 retains its role with an angle ce varying between 30 ° and 70 ° .
• the tests show that with a large diameter ball, for example 1.6 millimeters, it is sufficient that the axial height h of the frustoconical surface 12 is between 0.01 and 0.08 millimeter to avoid the appearance of burrs.
• the diameter of the ball may be less, up to 0.5 millimeter, or greater.
• the axial height h can then be modified proportionally so as to be between 0.6% and 5% of the diameter of the ball.
• the peripheral portion 11 has the shape of a circular ring due to the symmetry of revolution around the central axis Z of the tip body 2. This ring is flat before the flared portion 12 is produced by machining and the crimping of the ball 3, but it may be slightly deformed during these operations, and therefore the peripheral portion 11 may only be substantially flat when the ball point is finished.
• the peripheral portion 11 has a width 1_ measured in a radial direction of the opening 7, that is to say along a perpendicular to the central axis Z.
• the width 1_ must be sufficient to retain a drop of ink 18 without the latter reaching the outer periphery of the front face 4 and flowing over the radially outer wall of the tip body 2.
• the width 1 can be between 0.02 millimeter and 0.08 millimeter, that is to say between 1.2% and 5 % of the diameter of the ball.
• a greater width of the peripheral portion 11 is of course conceivable, but it would increase the size of the tip body 2.
• the width 1_ may be modified proportionally so as to be between 1.2% and 5% of the diameter of the ball. However, it is preferable that the width 1. be at least 0.01 millimeters to ensure the retention of an accumulation of ink.
• the axial height h of the flared portion 12 is substantially equal to the width 1_ of the peripheral portion 11, which offers a good compromise between the cleanliness of the ball point and the outside diameter of the face. before 4.
• the ball point according to the invention can be manufactured from a raw point body identical to those used to manufacture the ball points of the prior art and represented on the left half view of FIG. 1.
• the housing 6 of this raw tip body has a cylindrical front part 15 which opens into an opening 7 by forming a right angle 16 with the front face 4 of the tip body 2.
• the periphery of the opening 7 is chamfered so as to eliminate the right angle 16, then the ball 3 is inserted into the housing 6 through the opening 7.
• the diameter of the ball 3 is more or less equal to the diameter of the cylindrical part 15 of the housing 6 depending on whether one wishes to obtain a force-on or soft-friction insertion and a more or less large space between the ball and the wall of the housing. Then, the front end 10 of the tip body 2 is crimped against the ball so as to retain the latter in the housing 6. Thanks to crimping, the inner wall of the front end 10 follows the wall of the ball, leaving a determined space between these two walls.
• This manufacturing process has the advantage of being able to use the raw tip bodies of the prior art and requires only an additional step, the chamfering step, the other manufacturing steps being unchanged.
• the ball point according to the invention can be produced in large series without profoundly modifying the production tool.
• peripheral portion and of the flared portion can be adapted as a function of the diameter of the ball or of the thickness of the film present on the emerging part of the ball, in particular in the case of a ball point for an applicator. correction fluid or glue with a ball diameter of up to 3 millimeters.

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• Pens And Brushes (AREA)
• Coating Apparatus (AREA)
• Cosmetics (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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• 2002
  • 2002-07-01 FR FR0208189A patent/FR2841497B1/fr not_active Expired - Fee Related
• 2003
  • 2003-05-28 JP JP2004516834A patent/JP4468168B2/ja not_active Expired - Fee Related
  • 2003-05-28 CA CA2488282A patent/CA2488282C/en not_active Expired - Fee Related
  • 2003-05-28 WO PCT/FR2003/001618 patent/WO2004002750A1/fr not_active Ceased
  • 2003-05-28 AU AU2003249425A patent/AU2003249425C1/en not_active Ceased
  • 2003-05-28 MX MXPA05000230A patent/MXPA05000230A/es active IP Right Grant
  • 2003-05-28 CN CNB038158655A patent/CN100402312C/zh not_active Expired - Fee Related
  • 2003-05-28 BR BRPI0312192-5A patent/BR0312192B1/pt not_active IP Right Cessation
  • 2003-05-28 EP EP03761609.1A patent/EP1549508B1/de not_active Expired - Lifetime
• 2004
  • 2004-12-30 US US11/026,116 patent/US6971814B2/en not_active Expired - Fee Related

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