JP2011136556A - Cap for writing utensil and writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cap for a writing utensil which can hardly cause the finger to slip off its grip and can secure strength, and furthermore, can stably grip an article by a clip, and the writing utensil. <P>SOLUTION: The cap for the writing utensil comprises a cylindrical cap body formed of an elastic material which can protect a pen chip with a fitting hole 3c formed at the side surface of the cap body 3, and a clip member 2 having a base 4 and an insertion part 5 formed at the outer side surface of the base 4. In addition, the clip member 2 is installed to the cap body 3 in such a way that the base 4 can receive the apex of the writing utensil, and the insertion part 5 can extend to the outside of the cap body 3 through the fitting hole 3c. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a writing instrument cap and a writing instrument.

  For decoration purposes, a writing instrument cap formed by first molding an inner cap integrally provided with a clip and a housing and secondarily molding an outer cap that covers the entire inner cap and has a longer overall length than the inner cap. Is known (see Patent Document 1).

  In addition, for the purpose of making the writing instrument usable as a touch pen that is an input means of a computer or electronic notebook, a writing instrument having a through-hole through which the core of a mechanical pencil can be projected and retracted at the tip is formed of a soft elastic material. A cap-shaped grip for a writing instrument is known (see Patent Document 2).

  Furthermore, for the purpose of decoration, the number of parts is reduced, and a writing instrument cap having a cap body, a clip support portion fixed to the cap body, and a clip comprising a clip piece supported by the clip support portion is known ( (See Patent Document 3).

Japanese Patent Laid-Open No. 11-342697 JP-A-11-198585 Japanese Patent Laid-Open No. 2004-130681

  According to the writing instrument cap of Patent Document 1, the writing instrument cap is formed by two-color molding, but the effect is merely a decorative effect. Therefore, like the conventional writing instrument cap, there is a problem that the cap surface is slippery and is difficult to attach and detach from the writing instrument body. In addition, since the surface is slippery, there is a risk of falling out of a hand holding it or a chest pocket stored therein.

  Since the writing instrument grip of Patent Document 2 is formed of an elastic material, it has a structure that is less slippery than the writing instrument cap of Patent Document 1. However, what is described in Patent Document 2 is merely a grip for making the mechanical pencil usable as a touch pen, and the function as a cap is not considered. That is, the grip for a writing instrument of Patent Document 2 does not include a clip for holding an article such as a document or clothing, a seal rubber for preventing volatilization of ink from a writing part at the tip of the writing instrument, or the like. If the clip is to be attached to this structure, since the entire grip body is formed of an elastic material, the strength of the attachment portion is weakened, and therefore the article cannot be stably held. Further, since the whole is formed of an elastic material, buckling may occur when a force is applied in the axial direction of the writing instrument, such as when falling vertically, and the writing part at the tip of the writing instrument may be damaged.

  Since the writing instrument cap of Patent Document 3 is fitted to the writing tool main body only at the fitting portion provided on the inner wall of the cap main body, the fitting may be loosened when the clip piece is lifted to hold the article. Furthermore, this writing instrument cap is not configured to arrange a seal rubber for preventing volatilization of ink from the writing part at the tip of the writing instrument.

  Accordingly, an object of the present invention is to provide a writing instrument cap and a writing instrument that are not slippery and have sufficient strength and that can stably hold an article with a clip.

  In order to solve the above-described problem, according to the first aspect of the present invention, a cap body that is a cylindrical cap body for protecting the pen nib and is formed of an elastic body having attachment holes formed on the side surfaces, and a base portion And a clip member provided with a clamping part provided on the outer surface of the base part, wherein the base part receives the tip of the writing instrument, and the clip part extends outside the cap body through the attachment hole. A writing instrument cap is provided in which a member is provided to the cap body.

  That is, in the invention described in claim 1, since the cap body is made of an elastic body, the structure is difficult to slip. On the other hand, the strength of the cap body is reduced by making the cap body an elastic body, and the clip body has a base to reinforce the cap body because the clip itself is unstable and the clamping force of the article is weak. And it has been solved. Therefore, the writing instrument cap according to the present invention has an effect that it is difficult to slip and strength is secured, and the article can be stably held by the clip.

  Moreover, according to the invention of Claim 2, in the invention of Claim 1, the cap for writing instruments in which the said base is formed cyclically | annularly is provided. That is, in the invention described in claim 2, the writing instrument cap is reinforced against the load from the entire circumferential direction because the base portion is annular.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the inner wall of the cap body closer to the opening end side in the longitudinal direction than the base is connected to the fitting protrusion provided on the writing instrument body. A writing instrument cap provided with a locking projection for forming a fitting is provided. That is, in the invention described in claim 3, even the writing instrument cap having the novel configuration of the base can be fitted with the writing instrument body.

  According to a fourth aspect of the present invention, there is provided the writing instrument according to the third aspect, wherein the base portion further includes a rear end surface that comes into contact with a locking surface provided in the writing instrument body during the fitting. A cap is provided. That is, in the invention according to claim 4, the relative longitudinal direction positioning between the writing instrument cap and the writing instrument body can be performed. In addition, since the locking surface and the rear end surface come into contact with each other at the time of fitting, fitting with less looseness can be realized. Further, a clear sound and click feeling can be obtained when the cap is fitted, and the confirmation of the fitting becomes easy.

  According to the invention described in claim 5, in the invention described in any one of claims 1 to 4, at least one through-hole communicating with the inside is formed on the outer surface of the writing instrument cap. A writing instrument cap is provided. That is, in the invention according to claim 5, when the writing instrument cap is attached to or detached from the writing instrument body, air can freely enter and exit through the through hole. Therefore, the internal pressure of the writing instrument cap does not increase or decrease, and the writing instrument cap can be smoothly attached and detached. In addition, even if the cap is accidentally swallowed, suffocation can be prevented because it functions as a vent.

  According to the invention of claim 6, in the invention of any one of claims 1 to 5, when held by the inner wall of the tip portion of the cap body, and the writing instrument cap is attached to the writing instrument body, There is provided a writing instrument cap that further includes a seal member that engages with the writing part at the tip of the writing tool to seal the writing part. That is, in the invention described in claim 6, when the writing instrument uses highly volatile ink, the writing part is sealed, so that volatilization of the ink from the writing part can be prevented. . Furthermore, since the adhesiveness in attachment of a sealing member and a cap is high, it becomes difficult to remove a sealing member.

  According to the invention described in claim 7, in the invention described in any one of claims 1 to 6, a ball portion is formed at the rear end of the clamping portion, and the outer peripheral surface of the cap body is There is provided a writing instrument cap in which a concave portion having a shape corresponding to the ball portion is formed, and the ball portion and the concave portion are arranged to face each other. That is, in the invention according to claim 7, since the ball portion and the concave portion have corresponding shapes, articles to be sandwiched such as documents and clothes are also deformed to the same shape, so that it is difficult to come out and more securely. It becomes possible to pinch.

  Further, according to the invention described in claim 8, in the invention described in any one of claims 1 to 7, the cap main body is a mold having a gate portion other than a location corresponding to the vicinity of the top of the tip. A writing instrument cap that is injection molded using is provided. That is, in the invention according to claim 8, since the remaining gate (or gate mark) is not formed on the top of the cap body, the aesthetics are not impaired, and when the top is used as a handwriting erasing member, There is no worry about hurting.

  Moreover, according to the invention of Claim 9, the writing instrument equipped with the cap of any one of Claims 1 to 8 is provided.

  According to the invention described in each claim, there is a common effect that it is difficult to slip, strength is ensured, and an article can be stably held by a clip.

It is a perspective view of a writing instrument cap. It is a front view of the cap for writing instruments. It is a top view of the cap for writing instruments. It is a bottom view of a writing instrument cap. It is a right view of the cap for writing instruments. It is a left view of the cap for writing instruments. It is sectional drawing of the cap for writing instruments. It is a perspective view of the clip member of the cap for writing instruments. It is a right view of the cap for writing instruments equipped with the seal rubber. It is sectional drawing of the cap for writing instruments equipped with the seal rubber. It is a perspective view of the cap for writing instruments in which the hard ring is provided in the opening edge part. It is sectional drawing of the cap for writing instruments in which the hard ring is provided in the opening edge part. It is sectional drawing of the whole writing instrument equipped with the writing instrument cap. It is a partial expanded sectional view of the writing instrument tip shown in FIG.

  FIG. 1 is a perspective view of a writing instrument cap. Reference numeral 1 denotes the entire writing instrument cap, 2 denotes a clip member, and 3 denotes a cap body.

  The side surface of the cap body 3 is provided with two through holes 3 a that are arranged symmetrically with respect to the central axis of the writing instrument and communicate with the inside of the writing instrument cap 1 via the clip member 2. By providing the through hole 3a in the cap body 3, the air in the writing instrument cap 1 can freely enter and exit through the through hole 3a when the writing instrument cap 1 is attached to and detached from the writing instrument body. Therefore, the internal pressure of the writing instrument cap 1 does not increase or decrease, and the writing instrument cap 1 can be smoothly attached and detached. Further, the two through holes 3a are arranged symmetrically with respect to the axis, so that the air enters and exits from the two holes evenly and can be attached and detached more smoothly than when the two through holes 3a are not arranged symmetrically. In the present embodiment, there are two through-holes, but one or three or more may be provided, and they may be provided anywhere on the outer surface.

  A plurality of dimples 3b are formed on the outer peripheral surface of the side surface of the cap body 3 for further aesthetic effects and slip prevention. Instead of dimples, a pattern with grooves formed spirally around the outer peripheral surface, a pattern with grooves formed annularly along the outer peripheral surface, or a groove formed in a straight line extending in the longitudinal direction There may be a pattern or the like arranged around the screen.

  2 is a front view of the writing instrument cap 1, FIG. 3 is a plan view thereof, FIG. 4 is a bottom view thereof, FIG. 5 is a right side view thereof, FIG. 6 is a left side view thereof, and FIG. FIG. 8 is a cross-sectional view of the writing instrument cap 1, and FIG. 8 is a perspective view of a clip member of the writing instrument cap 1.

  In the present specification, the closed end side of the writing instrument cap is the front end or the front side, and the open end side of the writing instrument cap is the rear end or the rear side.

  The clip member 2 will be described with reference to FIGS. The clip member 2 includes a base portion 4 and a sandwiching portion 5 formed integrally with the outer surface of the base portion 4. In the present embodiment, the base portion 4 is formed in an annular shape, and is hereinafter referred to as an annular portion 4.

  The annular portion 4 has a rear-side diameter larger than the front-side diameter, has a substantially tapered outer appearance, and is configured to receive the tip of the writing instrument. The inner wall of the annular portion 4 is formed in a substantially cylindrical shape by a predetermined length inward from the front end portion and the rear end portion, and a region between these cylindrical shapes is formed in a tapered shape. Further, a notch portion 4a having the same shape as the through hole 3a is formed in a portion corresponding to the through hole 3a of the cap body 3 so that the outside and the inside of the writing instrument cap 1 communicate with each other. Furthermore, a plurality of guide protrusions 4b protruding toward the central axis along the longitudinal direction are provided at equal intervals on the rear cylindrical inner wall portion. The guide protrusion 4b will be described later.

  The clamping unit 5 is configured to have elasticity so that an article such as a document or clothing can be clamped between the cap body 3. A ball portion 5 a is integrally formed at the rear end of the clamping portion 5.

  Examples of the material forming the clip member 2 include synthetic resins such as polycarbonate and acrylonitrile / butadiene / styrene. However, in order to prevent breakage when the sandwiching portion 5 is bent, it may be formed using an elastic material, particularly the same elastic material as that of the cap body described below.

  The cap body 3 is a cylindrical member made of an elastic body whose one end is closed so as to protect the pen tip of the writing instrument, and a mounting hole 3c is formed on a side surface thereof. An annular portion 4 of the clip member 2 is disposed in the cap body 3, and a holding portion 5 of the clip member 2 is provided so as to extend out of the cap body 3 through the attachment hole 3c. That is, the cap body 3 closes the opening on the front side of the annular portion 4 of the clip member 2 and extends in a cylindrical shape by a predetermined length from the opening on the rear side to form an opening into which the writing instrument body is inserted.

  A concave portion 3d having a shape corresponding to the ball portion 5a may be formed on the outer peripheral surface of the cap body 3 facing the ball portion 5a of the clip member 2. When the ball part 5a and the recessed part 3d have shapes corresponding to each other, an article to be clamped such as a document or clothing is also deformed into the same shape, and is more securely clamped and is difficult to come off.

  As a material for forming the cap body 3, elastic materials such as rubber materials such as silicone rubber, nitrile rubber, ethylene propylene rubber and ethylene propylene diene rubber, and thermoplastic elastomers such as styrene elastomer, olefin elastomer and polyester elastomer, and the like The mixture of the above elastic materials and the mixture of an elastic material and a synthetic resin are mentioned.

  9 is a right side view of the writing instrument cap 1 on which the seal rubber 6 is mounted, and FIG. 10 is a cross-sectional view of the writing instrument cap 1 on which the sealing rubber 6 is arranged. The seal rubber 6 is disposed in the cap body 3 in order to prevent the ink from volatilizing from the writing portion at the tip of the writing instrument when the writing instrument in which the writing instrument cap 1 is used is a ballpoint pen using highly volatile ink. . 9 and 10 are the same as the diagrams shown in FIGS. 5 and 7 except that the seal rubber 6 is added.

  The seal rubber 6 in the present embodiment is made of an elastic body made of an arbitrary elastic material. As shown in FIG. 10, the seal rubber 6 has a substantially disk shape with circular concave portions coaxially on both surfaces, and has an H-shaped vertical cross-sectional shape. is doing. The seal rubber 6 may have other shapes such as a spherical shape.

  7 and 10, a plurality of ribs 3e extending toward the central axis along the longitudinal direction are provided on the inner wall at the front end of the cap body 3, and the seal rubber 6 is sandwiched while being elastically deformed. Yes. The ribs 3e are preferably arranged at equal intervals and three or more.

  When the writing instrument main body is inserted into the writing instrument cap 1 with the seal rubber 6 disposed in the cap main body 3, the writing portion at the tip of the writing instrument engages with the seal rubber 6. That is, when the writing portion presses the central portion of the seal rubber 6, the seal rubber 6 is elastically deformed and the writing portion is buried in the seal rubber 6. As a result, it is possible to prevent volatilization of ink from the writing unit.

  Further, when the seal rubber 6 is disposed in the cap main body 3 in the manufacturing process, the cap main body 3 is made of an elastic body. Therefore, the cap main body 3 is also elastically deformed when the seal rubber 6 is inserted. However, it can be reliably arranged.

  FIG. 11 is a perspective view of the writing instrument cap 1 in which the hard ring 8 is provided at the opening end, and FIG. 12 is a sectional view of the writing instrument cap 1 in which the hard ring 8 is provided at the opening end. is there. 11 and 12 are the same as those in the above embodiment except that the hard ring 8 is provided at the opening end of the writing instrument cap 1.

  Here, “hard” means at least harder than the material forming the cap body 3, and examples of the material forming the hard ring 8 include polycarbonate, glass, and metal. Further, the same material as that for forming the clip member 2 may be used.

  The hard ring 8 is an annular ring member formed in a substantially cylindrical shape, and is fitted to the outer peripheral surface of the opening end portion of the cap body 3. That is, on the outer peripheral surface of the cap body 3, an annular recess 3 g that receives the hard ring 8 over a predetermined length from the opening end is formed so as to receive the hard ring 8. The inner diameter of the hard ring 8 is substantially the same as or slightly smaller than the outer diameter of the recess 3g portion of the cap body 3. The outer diameter of the hard ring 8 is formed to be substantially the same outer diameter as that of the vicinity of the opening end of the cap body 3, and therefore forms substantially the same outer peripheral surface. In a state where the hard ring 8 is fitted, the rear end surface of the cap body 3 and the rear end surface of the hard ring 8 form substantially the same rear end surface.

  The substantially cylindrical hard ring 8 described above has a rectangular cross-sectional shape in the radial direction so that the outer peripheral surface and the rear end surface are flush with the other cap body 3 portion, but other cross-sectional shapes, for example, It may be circular or elliptical.

  The hard ring 8 is fitted into the recess 3g of the cap body 3 by press-fitting. In the case where the cap body 3 does not have sufficient rigidity and the hard ring 8 may come off, both may be bonded with an adhesive. The hard ring 8 may be provided on the cap body 3 by two-color molding together with the clip member 2 as will be described later.

  By providing the hard ring 8 at the opening end of the writing instrument cap 1, the opening end is prevented from being bent, so that the user can hold the writing instrument cap 1 firmly. Further, by using a material different from that of the cap body 3, the opening end portion has a texture different from that of the other cap body 3 portions, so that a decorative effect can be obtained.

  Next, the fitting when the writing instrument cap 1 is attached to the writing instrument body 7 will be described with reference to FIGS. 13 and 14. FIG. 13 is a cross-sectional view of the entire writing instrument equipped with the writing instrument cap 1, and FIG. 14 is a partially enlarged sectional view of the tip of the writing instrument equipped with the writing instrument cap 1.

  The writing instrument main body 7 has a writing part 7a, a fitting projection 7b, and a locking surface 7c. The writing part 7a shown in FIG.13 and FIG.14 is the writing part 7a of a ball-point pen, and the state in which the seal rubber 6 is elastically deformed is shown. The fitting projection 7b is a projection formed over the entire outer peripheral surface of the writing instrument body 7, and the locking surface 7c is the center of the writing instrument formed from the vicinity of the bottom of the fitting projection 7b on the writing unit 7a side. It is an annular plane that is substantially perpendicular to the axis. On the other hand, a locking projection 3f that engages with the fitting projection 7b of the writing instrument body 7 is formed on the inner wall of the cap body 3 on the rear side of the annular portion 4 of the clip member 2 over the entire circumference.

  When the writing instrument main body 7 is inserted into the writing instrument cap 1 from the right to the left in the drawing, first, the fitting protrusion 7b of the writing instrument main body 7 contacts and locks with the locking protrusion 3f of the cap main body 3. When the writing instrument body 7 is further pushed in from this state, the fitting projection 7b of the writing instrument body 7 and the locking projection 3f of the cap body 3 are pressed against each other, and a reaction force in the direction perpendicular to the central axis is generated in both. As a result, either one or both of the shrinkage direction of the writing instrument body 7 and the expansion direction of the cap body 3 are elastically deformed, and the fitting protrusion 7b of the writing instrument body 7 engages with the engaging protrusion 3f of the cap body 3. It is possible to pass through the inside of the cap body 3 away from the main body 3. After the fitting projection 7b of the writing instrument body 7 passes through the locking projection 3f of the cap body 3, the locking surface 7c of the writing instrument body 7 comes into contact with and engages with the rear end surface 4c of the annular portion 4 of the clip member 2. As shown in FIGS. 13 and 14, the fitting of the writing instrument cap 1 and the writing instrument body 7 is completed.

  When the fitting is completed, the direction in which the writing instrument main body 7 is pushed into the cap main body 3 is regulated by the engagement between the engaging surface 7c of the writing instrument main body 7 and the rear end surface 4c of the annular portion 4, and the writing instrument main body 7 is moved to the cap main body. The direction of removing from 3 is regulated by the engagement between the fitting protrusion 7b of the writing instrument body 7 and the engagement protrusion 3f of the cap body 3 in the direction opposite to the pushing direction.

  When removing the writing instrument cap 1 from the writing instrument body 7, the reaction force in the direction perpendicular to the central axis is applied by pulling the writing instrument body 7, as opposed to mounting the writing instrument cap 1 to the writing instrument body. To cause both. Due to the elastic deformation caused thereby, the engagement of the fitting projection 7b of the writing instrument body 7 and the locking projection 3f of the cap body 3 is released, and the writing instrument cap 1 can be removed from the writing instrument body 7.

  At the time of fitting, the locking surface 7c of the writing instrument body 7 and the rear end face 4c of the annular portion 4 are in contact with or close to each other, so that the writing instrument cap 1 itself is lifted when the clamping part 5 is lifted to clamp the article. Is absorbed by the annular portion 4 and the contact surface between the locking surface 7c and the rear end surface 4c. Therefore, the cap body 3 is not greatly deformed or moved with respect to the writing instrument body 7, and the engagement between the writing part 7a at the tip of the writing instrument and the seal rubber 6 is maintained without being released.

  The fitting projection 7b of the writing instrument body 7 and the locking projection 3f of the cap body 3 are formed over the entire circumference of the outer peripheral surface of the writing instrument body 7 and the entire circumference of the inner wall of the cap body 3, respectively. You may comprise so that it may be formed in a part.

  By adjusting the position of the rear end surface 4c of the annular portion 4 with respect to the cap body 3, the shape and position of the locking protrusion 3f of the cap body 3, and the shape of the fitting protrusion 7b of the writing instrument body 7, loosening (play) is achieved. It is possible to realize a more secure fitting with less. The position of the locking projection 3f is preferably closer to the rear end face 4c. Furthermore, since there is little loosening, the writing part 7a can be surely engaged with the seal rubber 6 and ink volatilization due to a sealing failure of the writing part 7a can be prevented. Further, the rear end surface of the cap body 3 and the portion of the writing instrument main body 7 engaged with the rear end surface have a gap so as not to hinder the above-described fitting and engagement between the writing portion 7a and the seal rubber 6. (Refer to part A in FIG. 13).

  The length in the longitudinal direction of the annular portion 4 of the clip member 2 can be variously set. However, the shorter the length, the lower the stability of the clamping portion 5 because the cap body 3 is an elastic body. . Accordingly, the length of the annular portion 4 in the longitudinal direction is determined so that the stability of the sandwiching portion 5 is within an allowable range. The rear end surface 4c of the annular portion 4 is preferably determined so as not to exceed the rear end surface of the cap body 3.

  When the writing instrument body 7 is inserted into the writing instrument cap 1, it is desirable to insert the writing instrument body 7 straight so that the center axis of the writing instrument cap 1 and the center axis of the writing instrument body 7 coincide. However, sometimes the writing instrument body 7 is not inserted straight into the writing instrument cap 1 but is inserted with the two central axes inclined. For this reason, both may not be able to be fitted well.

  Thus, as described above, even when the guide projection 4b is provided on the annular portion 4 of the clip member 2 and the writing instrument main body 7 is obliquely inserted into the writing instrument cap 1, the fitting is finally completed. Both central axes are configured to be guided in a coincident state. That is, since the guide protrusion 4b is provided in the annular portion 4 of the clip member 2, the substantial inner diameter of the annular portion 4 of the clip member 2 passing through the apex portion of the guide protrusion 4b does not have the guide protrusion 4b. The inner diameter of the cap becomes smaller. Therefore, looseness (play) between the annular portion 4 and the writing instrument body 7 is reduced, and the angle at which both central axes can be formed when the writing instrument body 7 is inserted becomes smaller. Therefore, when the writing instrument body 7 is inserted obliquely, the frictional resistance between the outer periphery of the writing instrument body 7 in contact with the guide projection 4b of the annular portion 4 becomes smaller, and the fitting is performed smoothly.

  Moreover, by having the guide protrusion 4b, a contact area with the outer periphery of the writing instrument main body 7 becomes smaller, and therefore the frictional resistance becomes smaller. The guide protrusion 4b may have other shapes, and the shape and length of the guide protrusion 4b may be such that the guide protrusion 4b and the front portion of the writing instrument body 7 do not contact or fit together. Even when the main body 7 is inserted obliquely, it is optimized so as not to cause poor fitting.

  The guide protrusion 4b is also useful for centering the writing instrument body 7 with respect to the writing instrument cap 1. That is, by having the guide protrusion 4b, as described above, the looseness between the annular portion 4 and the writing instrument body 7 is reduced, and accurate centering can be performed. Further, since the centering of the writing instrument body 7 is mainly performed by the guide protrusion 4b provided on the annular portion 4 of the clip member 2, the centering can be performed regardless of the overall length of the writing instrument cap 1.

  Further, the guide protrusion 4b provides a stable fitting when the writing instrument cap 1 is attached to the rear end 7d of the writing instrument body 7 during writing, for example. That is, the fitting of the writing instrument cap 1 to the writing part 7 a side of the writing instrument body 7 is a snap-type fitting, whereas the writing instrument cap 1 is fitted to the rear end 7 d of the writing instrument body 7. The fitting is performed by press fitting. Therefore, in addition to the relationship between the inner diameter of the annular portion 4 of the clip member 2 passing through the apex portion of the guide protrusion 4b and the outer diameter of the rear end portion 7d of the writing instrument body 7, the length of the press-fitting distance L in FIG. By doing so, it becomes possible to obtain a desired fitting force. As one guideline for setting the fitting force, in the state where the writing instrument cap 1 is fitted to the rear end portion 7d of the writing instrument body 7, the top portion of the cap body 3 is used as a handwriting erasing member, as will be described later. It is mentioned whether or not the paper is stable when it is rubbed.

  The writing instrument cap 1 can be produced, for example, by two-color molding. When the two-color molding is used, the clip member 2 is first molded first, and then the cap body 3 is secondarily molded to form a writing instrument cap.

  Two-color molding usually uses a mold and core pin for primary molding and secondary molding, and a writing instrument cap is molded around the tip of the core pin, but the core pin is held only at one end during injection molding. In such a case, the core pin may be bent and the like, and it may be impossible to mold into an accurate dimensional shape. That is, at the time of injection molding, the tip portion of the core pin is usually not fixed and is held only by the other end.

  Therefore, at the time of injection molding, a fixing pin protruding from the mold into the cavity contacts and supports the tip of the core pin, thereby fixing the tip of the core pin and preventing bending of the core pin at the time of injection molding. Since the fixed pin is in contact with the tip of the core pin even during injection molding, the molded product has a gap in the shape of the fixed pin. By utilizing this, by selecting the cross-sectional shape of the fixing pin, the cutout portion 4a of the clip member 2 can be formed in the primary molding, and the through hole 3a of the cap body 3 can be molded in the secondary molding. Note that the fixing pin may be provided on the core pin side.

  Since the cap body 3 occupying most of the surface of the writing instrument cap 1 is made of an elastic material, the writing instrument cap 1 and the writing instrument on which the writing instrument cap 1 is mounted are not slippery. Further, since the clip member 2 has the annular portion 4, a portion that is particularly loaded during the clamping operation is reinforced, so that strength can be ensured and the article can be stably clamped. Therefore, there is an advantage that the risk of dropping from a hand holding a writing instrument or a stored chest pocket is reduced as compared with a conventional writing instrument. In addition, in this embodiment, although the base 4 was formed in cyclic | annular form, the arbitrary shapes which can reinforce a cap main body, for example, the shape which has a C-shaped cross section, may be sufficient.

  In addition, for example, it is an operation that is often performed by the user, but it is also difficult to slip even when the writing instrument body is held with the palm, middle finger, ring finger, and little finger and the writing instrument cap is attached and detached with the index finger and thumb. There is also an advantage that it can be detached. Furthermore, for example, in a ballpoint pen that is vulnerable to vibration and impact, when the writing instrument falls vertically from the top of the cap, the impact on the writing instrument body is mitigated by the writing instrument cap made of an elastic body, and the clip member 2 provides strength. Secured. Thereby, there is also an advantage that the risk of occurrence of problems such as liquid leakage from the writing unit is reduced.

  Furthermore, since most of the writing instrument cap is covered with the elastic body, it can be used as an erasing member for erasing the handwriting drawn by the writing instrument by rubbing with any part covered with the elastic body. it can. For example, the writing instrument cap can be used for erasing handwriting with a pencil, and when used for a writing instrument having ink that changes color due to heat, frictional heat is generated by rubbing the paper surface. The handwriting drawn on can be discolored. Note that the surface roughness of the cap surface is preferably Ra = 0.0009 μm to 0.014 μm. If it is smoother than 0.009 μm, it may slip on the paper surface, and if it is 0.014 μm or more, the paper surface may be caught carelessly. Further, by setting the durometer hardness defined in JIS K6253 D to 35 to 90, it is possible to easily generate frictional heat without damaging the paper surface while improving the rigidity of the entire cap.

  In addition, when using the part covered with the elastic body as an erasing member, the erasing member is usually fitted to the end of the writing instrument body opposite to the writing part, as seen on a pencil with an eraser. Therefore, there is also an advantage that a problem such as detachment of the erasing member does not occur.

  In addition, in the injection molding of the cap body 3, the gate portion that is the entrance to the cavity of the mold is not the top of the cap body 3, but the side surface, for example, the cap body is applied to the writing surface or the paper surface even if the cap body is inclined at 45 °. By disposing at a position that does not contact, the top surface can have a smooth appearance. Further, when the top portion is used as an erasing member, it can be used without problems such as damage to the paper surface due to a so-called gate residue (or gate trace).

DESCRIPTION OF SYMBOLS 1 Writing instrument cap 2 Clip member 3 Cap body 3c Mounting hole 4 Annular part, base part 5 Clamping part

Claims (9)

  A cylindrical cap body for protecting the nib, which is made of an elastic body having attachment holes formed on the side surfaces thereof, and a clip member having a base portion and a clamping portion provided on the outer surface of the base portion. A writing instrument cap provided with the clip member on the cap body so that the base portion receives the tip of the writing tool and the clamping portion extends out of the cap body through the attachment hole.   The writing instrument cap according to claim 1, wherein the base is formed in an annular shape.   The writing instrument cap according to claim 1 or 2, wherein a locking projection that forms a fitting with a fitting projection provided on the writing instrument body is provided on the inner wall of the cap body closer to the opening end side in the longitudinal direction than the base portion. .   The writing instrument cap according to claim 3, wherein the base further includes a rear end face that comes into contact with a locking surface provided in the writing instrument body during the fitting.   The writing instrument cap according to any one of claims 1 to 4, wherein at least one through-hole communicating with the inside of the outer surface of the writing instrument cap is formed.   6. The seal member according to claim 1, further comprising a seal member that is held by an inner wall of the tip end portion of the cap body and seals the writing portion by engaging the writing portion at the tip end of the writing instrument when the writing instrument cap is attached to the writing instrument body. A writing instrument cap according to any one of the above.   A ball portion is formed at a rear end of the clamping portion, a concave portion having a shape corresponding to the ball portion is formed on an outer peripheral surface of the cap body, and the ball portion and the concave portion are arranged to face each other. The cap for writing instruments as described in any one of 1-6.   The writing instrument cap according to any one of claims 1 to 7, wherein the cap body is injection-molded using a mold having a gate portion other than a location corresponding to the vicinity of the top of the tip.   A writing instrument equipped with the cap according to any one of claims 1 to 8.

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