JP6288924B2 - Parts for writing instruments and writing instruments having the parts - Google Patents

Description

  The present invention relates to a writing instrument component and a writing instrument having the component.

  A cylindrical part having a male screw formed on the outer peripheral surface of one end, for example, a front shaft of a shaft cylinder, and a cylindrical part having a female screw threadedly engaged with the male screw on the inner peripheral surface of one end, for example, a rear shaft of the shaft cylinder Writing instruments are known.

  Patent Document 1 discloses a writing instrument that is attached to a rear end portion of a lead tank of a mechanical pencil and has a holder having an external thread formed on an outer peripheral surface thereof, and a rotating sleeve having an internal thread that is screwed with the external thread. Yes. The cylindrical part in which the male screw of the holder is formed is divided into half-cylindrical halves by a slit extending from the tip to the whole male screw part in the axial direction, and each half can be bent inward from each other. It has become. Therefore, when assembling the holder to the rotating sleeve, the holder can be rotated and screwed together, but it is also possible to complete the assembly by inserting the semi-cylindrical half into the rotating sleeve while bending it. Become.

Japanese Patent Publication No. 7-61758

  However, in the writing instrument described in Patent Document 1, since the slit is formed from the end surface of the cylindrical part to the entire male screw part, that is, the holder in which the male screw is formed, the semi-cylindrical half is easily bent inward. While the assembly is facilitated, there is a problem that the fastening force between the two parts is weak. Further, since the semi-cylindrical half is supported only at its base and not at the tip, there is a risk of plastic deformation while bending inward, and there is a risk of breakage. There is also.

  The present invention relates to a writing instrument part having a strong fastening force between both parts while assembling the other part by inserting without rotating one part in the assembly between the parts that can be screwed together. It aims at providing the writing instrument which has components.

According to one aspect of the present invention, it comprises a first cylindrical part having a male thread part in which a male screw is formed, and a second cylindrical part having a female thread part in which a female screw threadedly engaged with the male screw is formed, The male threaded portion of the first cylindrical part is disposed apart from the tip and is provided with an elongated hole extending in the axial direction. The male threaded portion has a continuous thread on the side opposite to the tip. There is provided a part for a writing instrument, characterized in that it has a portion that is provided.

  That is, according to the first aspect of the present invention, in assembling the parts that can be screwed together, the second cylindrical part is assembled by inserting without rotating the first cylindrical part, and It is possible to provide a writing instrument part having a strong fastening force and a writing instrument having the part.

  That is, when the first cylindrical part is inserted into the second cylindrical part without rotating, the force in the central axis direction is applied to the male screw part by the contact between the male screw thread and the female screw thread. Join. At this time, the first cylindrical part is elastically contracted and deformed so that the opening area of the elongated hole becomes small, and the assembly can be completed. And compared with the external thread of the patent document 1 in which the slit was formed from the front-end | tip, this invention in which the elongate hole was provided in the position spaced apart from the front-end | tip is that an external thread part is not greatly elastically deformed or plastically deformed. There are also advantages that it is difficult to come off, exhibits a strong fastening force, has excellent durability, and does not impair the appearance. Furthermore, when assembling, the axial force is only applied to the first cylindrical part and inserted into the second cylindrical part, so that the first cylindrical part is rotated and screwed. Thus, the assembly can be completed in a shorter time.

Before SL elongated holes may be provided in opposed pairs with respect to the central axis of the first cylindrical part.

That is, since the fine slot is provided in pairs in symmetrical positions, a male screw portion is uniformly elastically deformed, it is possible to perform smoother assembly.

In longitudinal section of the thread before Symbol male screw and the female screw, the slope of the front end side of the thread may be slower than the slope of the opposite side of the thread.

That is, the resistance from that slopes of the thread of the previous end is gradual than the slope of the opposite side of the thread, the direction of the force of inserting the first cylindrical part in the second cylindrical inner part There is little, and resistance becomes larger with respect to the force in the direction of taking out the first cylindrical part from the second cylindrical part. Therefore, it is possible to obtain a stronger fastening force because the assembly becomes easy and it becomes difficult to come off.

A front barrel at one axial tube before Symbol cylindrical part, the other of may be a rear axle of the barrel.

According to another aspect of the present invention, there is provided a writing instrument comprising the above-mentioned parts for a writing instrument.

According to the present invention, in the assembly between the parts that can be screwed together, a strong fastening force is applied between both cylindrical parts while assembling the second cylindrical part by inserting without rotating the first cylindrical part. It is possible to provide a writing instrument having a component and a writing instrument having the component.

It is a disassembled perspective view of the writing instrument which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view of the axial cylinder of the writing instrument shown in FIG. It is a top view of the front axis | shaft of the axial cylinder of the writing instrument shown by FIG. It is a longitudinal cross-sectional view of the front axis | shaft shown by FIG. It is a longitudinal cross-sectional view of the screw thread of the external thread and internal thread in one Embodiment of this invention. It is a longitudinal cross-sectional view of the thread of the external thread and internal thread in another embodiment of this invention. It is a longitudinal cross-sectional view of the screw thread of the external thread and internal thread in another embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding components are denoted by common reference symbols throughout the drawings.
FIG. 1 is an exploded perspective view of a writing instrument 1 according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a shaft tube 2 of the writing instrument 1 shown in FIG. 1, and FIG. FIG. 4 is a plan view of the tip shaft 3 of the shaft cylinder 2 of the writing instrument 1 shown in FIG. 4, and FIG. 4 is a longitudinal sectional view of the tip shaft 3 shown in FIG. Here, in this specification, the side from which the writing part protrudes is defined as the “front” side, and the side opposite to the writing part is defined as the “rear” side.

  The writing instrument 1 has a shaft cylinder 2 made of a resin material, and the shaft cylinder 2 has a front shaft 3 and a rear shaft 4. A writing body 5 such as a refill or a ballpoint pen is accommodated in the shaft tube 2, and the writing member at the tip of the writing body 5 is moved from the shaft tube 2 by knocking the knock member 6 provided at the rear portion of the shaft tube 2. Projects or retracts into the barrel 2. The knock member 6 is integrally provided with a clip 7, and moves forward or backward as the knock member 6 knocks. The exposed outer surface of the front shaft 3 is covered with a grip member 8 made of an elastic material such as an elastomer so that the user can easily grip it.

  The front shaft 3 has a male screw portion 3a in which a male screw is formed on the outer peripheral surface of the rear end. The rear shaft 4 has an internal thread portion 4a in which an internal thread is formed on the inner peripheral surface of the front end. Here, the male screw portion 3a and the female screw portion 4a mainly refer to a cylindrical peripheral surface corresponding to the complete screw portion. The male screw portion 3a of the front shaft 3 is disposed away from the tip (screw tip) when the rear end of the front shaft 3, that is, the rear end portion is a male screw. That is, between the front end of the male screw (that is, the rear end of the front shaft 3) and the male screw portion 3a, there is a cylindrical region 3b that is substantially the same as the root diameter of the male screw of the male screw portion 3a, that is, the outer diameter of the shaft.

  The male screw portion 3a of the front shaft 3 is provided with two elongated holes 3c that penetrate the cylindrical peripheral surface portion in the axial direction. That is, the elongated hole 3c divides the threads in the circumferential direction so that all the threads of the male screw portion 3a are not continuously formed around the axis by one round. However, the elongated hole 3c may be formed so that the screw thread on the side opposite to the tip of the male screw portion 3a (that is, the front end side of the front shaft 3) remains continuously several times.

  The two elongated holes 3 c are disposed so as to face the central axis of the tip shaft 3. The number of the elongated holes 3c may be one or three or more, and in the case of three or more, it is preferable that the elongated holes 3c are arranged at equal intervals around the central axis of the front shaft 3. Further, the width in the circumferential direction of the elongated hole 3c is preferably about 25% of the shaft outer diameter of the male screw portion 3a.

  In order to assemble the front shaft 3 and the rear shaft 4 to obtain the shaft cylinder 2, the front shaft 3 is rotated with respect to the rear shaft 4 so that the male screw of the male screw portion 3a and the female screw of the female screw portion 4a are screwed together. However, the assembly can be completed by applying an axial force to the front shaft 3 and inserting it into the rear shaft 4.

  That is, if the front shaft 3 is inserted into the rear shaft 4 without rotating, the center axis line with respect to the male screw portion 3a is brought into contact with the male screw thread of the male screw portion 3a and the female screw thread of the female screw portion 4a. Directional force is applied. At this time, the front shaft 3 is elastically contracted and deformed so that the opening area of the elongated hole 3c becomes small, and the assembly can be completed. And compared with the external thread of patent document 1 in which the slit was formed from the front-end | tip, this invention in which the elongate hole 3c was provided in the position spaced apart from the front-end | tip WHEREIN: The external thread part 3a may also be greatly elastically deformed or plastically deformed. Therefore, there is an advantage that a strong fastening force is exhibited, durability is excellent, and appearance is not impaired. Furthermore, since the elongated hole 3c is formed in the male screw portion 3a, the contact area with the female screw is reduced during screwing compared to a normal male screw portion having no elongated hole, and wear resistance is increased. Also excellent. Furthermore, when assembling, since the axial force is only applied to the front shaft 3 and inserted into the rear shaft 4, it is shorter than the case where the front shaft 3 is rotated and screwed. The assembly can be completed.

  Further, in the present embodiment, since the elongated holes 3c are provided in pairs at symmetrical positions, the male screw portion 3a is elastically deformed uniformly, and a smoother assembly can be performed.

  FIG. 5 is a longitudinal sectional view of the above-described male screw and female screw thread 10 of the present invention. In the thread 10, the thread slope 10 a on the tip side of the screw and the thread slope 10 b on the opposite side are inclined at the same angle.

  FIG. 6 is a longitudinal sectional view of a thread 11 of a male screw and a female screw in another embodiment of the present invention. In the thread 11, the thread slope 11 a on the tip side of the screw is gentler than the thread slope 11 b on the opposite side. That is, there is little resistance to the force in the direction of inserting the front shaft 3 into the rear shaft 4, and the resistance is greater to the force in the direction of taking out the front shaft 3 from the rear shaft 4. Therefore, it becomes easy to assemble, and it becomes difficult to come out after assembling, so that a stronger fastening force can be obtained.

  FIG. 7 is a longitudinal sectional view of a thread 12 of an external thread and an internal thread in still another embodiment of the present invention. In the thread 12, the thread slope 12 a on the tip side of the screw is gentler than the thread slope 12 b on the opposite side. Further, the slope 12a of the screw thread has a stepwise inclination. Furthermore, the top of the thread is flat in the above-described embodiment, but is formed at an acute angle in this embodiment. That is, there is little resistance to the force in the direction of inserting the front shaft 3 into the rear shaft 4, and the resistance is greater to the force in the direction of taking out the front shaft 3 from the rear shaft 4. Further, the resistance to the force in the extracting direction is further increased by the engagement of the apexes of the acute angle of the thread 12. Therefore, it becomes easy to assemble, and it becomes difficult to come out after assembling, so that a stronger fastening force can be obtained.

  In the above-described embodiment, the present invention is applied to the front and rear shafts which are parts for writing instruments. However, other parts for writing instruments such as mouthpieces and front shafts, holders such as erasers, and rotating sleeves. For example, the present invention may be applied.

DESCRIPTION OF SYMBOLS 1 Writing instrument 2 Shaft cylinder 3 Lead shaft 3a Male thread part 3b Cylindrical area | region 3c Elongate hole 4 Back axis | shaft 4a Female thread part 5 Writing body 6 Knock member 7 Clip 8 Grip member

Claims (2)

A first cylindrical part having a male thread part on which a male screw is formed; and a second cylindrical part having a female thread part on which a female screw threadedly engaged with the male screw is provided, the male screw of the first cylindrical part The portion is disposed away from the tip and is provided with an elongated hole in the axial direction .
The part for a writing instrument , wherein the male screw portion has a portion in which a screw thread is continuous on the side opposite to the tip . A writing instrument comprising the part for a writing instrument according to claim 1 .

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