JP2003154783A - Writing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing implement which enables removable fitting of a cap by screwing without providing the fore end part of a holder tube with an external thread part engaging with an internal thread part formed in the cap, in regard to the writing implement wherein the cap is fitted by screwing it removably to the fore end part of the holder tube so as to protect a writing tip provided at the fore end of the holder tube. SOLUTION: Projections for screwing which engage with the internal thread part of the cap are provided on the outer peripheral surface of the fore end part of the holder tube corresponding to the internal thread part. In this structure, the cap is screwed on the fore end part of the holder tube by fitting the projections and the internal thread part to each other by screwing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument in which a cap is detachably attached to the tip of a barrel by screw fitting.

[0002]

2. Description of the Related Art Conventionally, in order to protect the writing tip provided at the tip of a barrel, a writing instrument having a cap detachably attached to the tip of the barrel by screw fitting, has a female screw inside the cap. And a male screw portion that meshes with the female screw portion is formed on the outer peripheral surface of the tip portion of the barrel corresponding to the female screw portion.

In a writing instrument having such a structure, regardless of whether it is preferred or not, a male screw portion must be formed on the outer peripheral surface of the tip end portion of the barrel, so that there is a design restriction at the tip end of the barrel. There is a problem of receiving. Further, when the male screw portion is formed on the outer peripheral surface of the barrel located near the writing tip, there is a problem that a finger or the like touches the male screw portion during writing, which causes discomfort.

[0004]

The present invention has been made in view of these facts, and in order to protect the writing tip provided at the tip of the barrel, a cap is attached to and detached from the tip of the barrel by screw fitting. An object of the present invention is to provide a writing instrument in which the cap can be freely attached and detached by screwing, without providing a male thread portion that meshes with a female thread portion formed in the cap at the tip end portion of the barrel. To do.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a writing instrument in which a cap is detachably attached to the tip of the barrel by screw fitting in order to protect the writing tip provided at the tip of the barrel. To form a female threaded portion on the cap, and to provide a threaded protrusion on the outer peripheral surface of the tip of the barrel for engaging the female threaded portion of the cap. It is a writing instrument characterized in that it is screwed onto the tip of the.

Further, there is provided a writing instrument in which the screw projection is provided so as to be displaceable inward in the radial direction.

In the present invention, the number of screw projections that mesh with the female screw portion of the cap provided at the tip of the barrel may be one or more, and the number is not limited. When a plurality of screw projections are provided, it is preferable that all of the screw projections engage with the female screw portion of the cap. To do this, it is sufficient to arrange each screw projection so as to be positioned on a line that is the same as the spiral of the female screw portion of the cap. Also, when the female screw is a double-threaded screw and two screw protrusions are provided. The two screw projections may be provided at circumferential positions facing each other with the shaft center interposed therebetween.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. Although a fountain pen is used as the writing tool in the present embodiment, the present invention is not limited to this, and a ballpoint pen, a mechanical pencil, a felt-tip pen, or the like may be used. In the drawings, the same members are designated by the same reference numerals when the same parts are shown.

The fountain pen 1 of the first embodiment will be described with reference to FIGS. The fountain pen body 2 of the fountain pen 1 in the present embodiment has a front shaft 3 called a neck shaft, a pen 4 attached to the tip of the front shaft 3 and a comb groove 5 as in the structure of the conventional fountain pen body. A pen tip 6 having a pen core 6 and a rear shaft 8 which is detachably connected to the rear end of the front shaft 3 by screw fitting and has a tail cap 7 attached to the rear end, which is called a body shaft.
Although not shown in the drawing, the ink cartridge and the ink suction device, which are accommodated in the front shaft 3 and / or the rear shaft 8 and are capable of accommodating ink inside the rear end portion of the pen core 6, are formed. Has been done. The cap 9 covering the front shaft 3 for protecting the pen 4 has a crown 10 fixed to the tip of the head side 9a, and a clip 11 provided on the outer peripheral surface of the head side 9a. On the inner wall surface of the opened rear end side 9b, a female screw portion 1
2 is formed.

The front outer peripheral surface 13 of the rear shaft 8 has an opening end surface 14 of the cap 9 when the front shaft 3 is covered with the cap 9.
The ring portion 15 protruding outward is formed integrally with the rear shaft 8. Further, on the outer peripheral surface 13 at the front of the ring portion 15, screw projections 16 that mesh with the female screw portion 12 of the cap 9 are provided at three positions so as to divide the circumference into three equal parts. Each screw projection 16 is provided so as to be located on a line that is the same as the spiral of the female screw portion 12 of the cap 9. The internal mechanism is omitted in FIG.

In the present embodiment, the screw projection 16 that meshes with the internal thread portion 12 of the cap 9 is provided on the outer peripheral surface 13 of the rear shaft 8. However, whether the screw projection 16 is provided on the front shaft 3 or the rear shaft 8. Depends on the position of the female screw portion 12 formed on the cap 9, and is provided on the outer peripheral surface 17 of the front shaft 3 depending on the position of the female screw portion 12.

In order to cover the front shaft 3 of the fountain pen body 2 with the cap 9, the pen 4 and the front shaft 3 are covered with the cap 9 as in the conventional case.
It suffices to insert it inside and rotate the fountain pen body 2 to engage the screw projection 16 with the female screw portion 12 and screw it.

The fountain pen 21 of the second embodiment is shown in FIG.
This will be described with reference to FIG. The fountain pen 21 of the present embodiment is
The fountain pen 1 of the first embodiment differs from the fountain pen 1 in how the screw projection 16 provided on the rear shaft 8 is provided, and the other portions are formed in the same manner as in the first embodiment. Although not shown in FIGS. 4 to 7, the outer peripheral surface 13 in front of the rear shaft 8 of the fountain pen body 22 formed in the same manner as in the first embodiment,
At the same positions as in the case of the first embodiment, the through holes 23 are formed at three positions, which divide the outer peripheral surface 13 facing the female screw portion when the front shaft 3 is covered with the cap into three parts on the circumference. It is provided. Each through hole 23 is arranged so as to be located on a line that is the same as the spiral of the female screw portion of the cap.

On the inner wall surface of the rear shaft 8 having the through hole 23,
The concave groove 24 having a spiral shape similar to the spiral is provided,
A ring-shaped spring 25 having a flat plate shape and a C-shape as shown in FIG. 7 is inserted into the groove 24, and female screw portions (not shown) of the three caps formed on the ring spring 25.
A screw projection 26 that meshes with the above is provided so as to project outward from each through hole 23.

FIG. 8 shows another embodiment of the ring spring. In the ring spring 27 of the present embodiment, the wire 28 is formed into a C-shape and the screw projection 2 is formed.
6 is formed by bending the wire 28.

In order to cover the front shaft 3 of the fountain pen main body 22 with the cap, the front shaft 3 is inserted into the cap 9 and the fountain pen main body 22 is rotated to form a through hole, as in the first embodiment. The screw projection 26 or 29 protruding from 23 may be engaged with the female screw portion of the cap and screwed.

[0017]

As described above, the writing instrument of the present invention has a cap detachably attached to the tip of the barrel by screw fitting in order to protect the writing tip provided at the tip of the barrel. However, since it is not necessary to provide a male threaded portion corresponding to the female threaded portion of the cap at the tip of the shaft cylinder, the shape of the tip of the shaft cylinder is neat, and when the writing instrument is gripped during writing, There is no discomfort caused by touching the male screw part with a finger or the like.

Further, in the invention according to claim 2,
Since the screw projections are provided so as to be elastically displaceable in the radial direction of the barrel, there is an advantage in that the screw projections can be easily engaged with the female thread portion of the cap. It is necessary to arrange so that the threaded protrusions are located on the same line as the spiral of the female threaded portion of the cap, but since they can be elastically engaged with the female threaded portion of the cap, It is not necessary to set the position to severe.

[Brief description of drawings]

FIG. 1 is a plan view of the fountain pen showing the fountain pen of the first embodiment, in which the cap is removed from the body of the fountain pen and the cap is longitudinally sectioned.

FIG. 2 is a plan view of the fountain pen showing a state in which the cap is screw-fitted to the body of the fountain pen.

FIG. 3 is an enlarged transverse cross-sectional view of the rear shaft of the II line portion in FIG. 1 with the internal mechanism omitted.

FIG. 4 is an enlarged plan view of a main part of a fountain pen showing a second embodiment.

5 is a vertical cross-sectional view of a main part of the fountain pen in FIG.

FIG. 6 is an enlarged end view of a portion of a line II-II in FIG. 4 showing a relationship between a rear shaft and a ring spring without an internal mechanism.

FIG. 7 is a plan view of a ring spring.

FIG. 8 is a plan view of a ring spring showing another embodiment of the ring spring.

[Sign name]

1.21 fountain pen 2, 222 fountain pen body 3 front axis 8 Rear axle 9 cap 12 Female thread 16 Screw projection 23 Through hole 25, 27 ring spring 26, 29 Screw projection

Claims (2)

[Claims] 1. A writing instrument comprising a cap, which is detachably attached to the shaft cylinder by screw fitting in order to protect the writing tip provided at the tip of the shaft cylinder. A writing instrument characterized in that a threaded projection is provided on the outer peripheral surface of the cylinder, the threaded projection meshing with the female threaded section of the cap, and the cap is screwed onto the tip of the barrel by screwing the threaded projection with the female threaded section. 2. The writing instrument according to claim 1, wherein the screw projection is provided so as to be elastically displaceable in a radial direction.