JP7720741B2 - removable writing instrument - Google Patents

Description

The present invention relates to a retractable writing instrument in which a core housed within a barrel is retracted at the front end of the barrel.

Conventional inventions of this type include, for example, a retractable writing instrument, as described in Patent Document 1, in which a cover member is provided at the front end of a core for a marker pen that retracts at the front end of the barrel, covering the writing part in a cylindrical shape and allowing the writing part to retract by moving back and forth.
In this retractable writing instrument, when the marker pen core is advanced and passes through the opening at the front end of the barrel, the cover member interferes with the inner surface of the barrel and moves back relatively, exposing the writing part, which has the effect of preventing the tip of the barrel from getting dirty.

Japanese Patent Application Laid-Open No. 2020-179623

However, with the above-mentioned conventional technology, the through-hole provided in the peripheral wall of the cover member can interfere with surrounding parts (such as the writing part of a ballpoint pen refill or the step formed at the connection point between the barrel and the tip) when the entire core moves forward or backward, resulting in malfunction. In particular, if the writing part of a ballpoint pen refill gets caught in the guide hole, there is a high possibility of malfunction.

In view of the above problems, the present invention has the following configuration.
A retractable writing instrument comprising a barrel and a core housed within the barrel, the core extending and retracting from the front end of the barrel, wherein the core comprises a writing portion at the front end, a cover member that covers the writing portion in a cylindrical shape and moves back and forth to cause the writing portion to appear and disappear, and a cover support portion that supports the cover member from the inside so that it can move back and forth, the cover support portion having an engaging protrusion that protrudes radially outward from the barrel, the cover member having a through guide hole through which the engaging protrusion can be inserted so that it can move back and forth, and a chamfered portion provided on the radially outer side of the inner edge of the front end or the inner edge of the rear end of the guide hole .

The present invention is configured as described above, preventing the core from interfering with surrounding areas as it moves back and forth.

1 is a vertical cross-sectional view showing an example of a retractable writing instrument according to the present invention. FIG. 2 is a perspective view showing the retractable writing instrument with the front shaft removed. FIG. 2 is an exploded perspective view of the main parts of the retractable writing instrument. 3 is a plan view showing an example of a cover member of the retractable writing instrument. FIG. FIG. 10 is an enlarged longitudinal cross-sectional view of the main part of the retractable writing instrument, showing a state in which the writing part of one of the central cores is protruded. FIG. 1 is a perspective view showing another example of a retractable writing instrument according to the present invention, in which the front barrel is not shown. 10A to 10D are plan views showing other examples of the cover member.

This embodiment discloses the following features.
The first feature is a retractable writing instrument comprising a barrel and a core housed within the barrel, the core extending and retracting from the front end of the barrel, the core comprising a writing portion at the front end, a cover member that covers the writing portion in a cylindrical shape and moves back and forth to cause the writing portion to appear and disappear, and a cover support portion that supports the cover member from the inside so that it can be advanced and retracted, the cover support portion having an engaging protrusion that protrudes outward in the radial direction of the barrel, the cover member having a through guide hole through which the engaging protrusion can be inserted so that it can be advanced and retracted, and the inner edge of the front end or the inner edge of the rear end of the guide hole has an inclined edge portion that is inclined relative to the circumferential direction of the barrel (see Figures 1 to 8).

A second feature is that the inner edge of the front end or the inner edge of the rear end of the guide hole has a shape in which the central portion in the circumferential direction of the barrel protrudes in one direction in the axial direction of the barrel, and both sides of the protruding end each form the inclined edge portion (see Figure 4).

A third feature is that the inner edge at the front end or the inner edge at the rear end of the guide hole is curved continuously to form the inclined edge portion (see Figure 8(b)).

A fourth feature is that a chamfer is provided on the radially outer side of the inclined edge (see Figure 5).

A fifth feature is that multiple cores are provided within the barrel, and the cover member is provided on at least one of these cores (see Figures 1, 2, and 6).

A sixth feature is that multiple cores are provided lined up in the axial direction of the barrel, and the guide hole opens in a direction that intersects the line-up of the multiple cores (see Figure 7).

<Specific embodiment>
Next, specific embodiments having the above-mentioned features will be described in detail with reference to the drawings.

In this specification, the barrel axis direction refers to the direction along the barrel centerline, and the barrel circumferential direction refers to the direction around the barrel centerline. Additionally, "front" refers to the side of the barrel axis in which the writing part protrudes, and "rear" refers to the opposite side.
In this specification, the term "diametric direction of the barrel" refers to the direction of the barrel diameter perpendicular to the centerline of the barrel, the term "outer side of the barrel diameter" refers to the direction away from the barrel center along the barrel diameter direction, and the term "inner side of the barrel diameter" refers to the direction toward the barrel center along the barrel diameter direction.

FIG. 1 shows an example of a retractable writing instrument according to the present invention.
This retractable writing instrument 1 comprises a barrel 10, a plurality of (two in the illustrated example) operating members 20 exposed to the outside at the rear end of the barrel, and a core 30 connected to the front end of each operating member 20 and housed within the barrel 10, and is configured so that the core 30 corresponding to the selected operating member 20 retracts at the front end of the barrel 10.

The barrel 10 is formed in a long, roughly cylindrical shape, with a tapered tip 11 at its front end and a window 12 on the peripheral wall at its rear end that exposes the operating member 20. The window 12 also includes a guide surface 13 that guides the operating member 20 in the forward and backward directions, and a latching portion 14 that latches the operating member 20 when it moves forward (see Figure 1).

In the illustrated example, the barrel 10 is composed of a front barrel 10a and a rear barrel 10b that is detachably connected to the opening at the rear end of the front barrel 10a. In addition to the illustrated example, the barrel 10 can also be composed of a single cylindrical member, or three or more cylindrical members.

In the illustrated example, the barrel 10 has a width W in the direction in which the two cores 30 are aligned, which is greater than the width in the direction substantially perpendicular to this width W (see FIG. 2).
The cross-sectional shape of the barrel 10 may be, for example, a circle, an elongated hole, a rectangle, a diamond, or the like.

The operating member 20 is detachably connected to the rear end of each core 30 so as to move forward and backward integrally with the core 30. One end of this operating member 20 is biased rearward by a biasing member 50 (in the illustrated example, a compression coil spring) hooked to a fixed portion within the barrel 10 (in the illustrated example, a divider 40).
When the operating member 20 is pushed forward, it advances while sliding against the guide surface 13 inside the barrel 10, sinks into the barrel, and engages with the locked portion 14 inside the barrel. When another operating member 20 advances, the operating member 20 comes into contact with the advancing operating member 20, thereby releasing the locked state and moving backward due to the biasing force of the biasing member 50.

The front end side of each of the plurality of operating members 20 configured as described above is inserted into the divider 40 inside the barrel 10 .
The divider 40 is a substantially cylindrical member fixed to the inner peripheral surface of the barrel 10, and has a plurality of through holes 41 through which the plurality of operating members 20 are inserted so as to be able to advance and retreat.

A plurality of (two in the illustrated example) cores 30 are provided so as to be spaced apart in the radial direction of the barrel 10, and each is detachably connected to the front end side of the operating member 20.
Each core 30 comprises a long, shaft-shaped filling 31, a pen shaft 32 connected to the front end of the filling 31 and extending forward, an approximately cylindrical case 33 covering the filling 31 and the pen shaft 32, a cover member 34 attached to the front end of the case 33 so as to be movable back and forth and cylindrically covering the writing portion 30a at the front end of the pen shaft 32 and moving back and forth to cause the writing portion 30a to appear and disappear, and a biasing member 35 which biases the cover member 34 forward, thereby forming a writing core for a marker pen.

The padding 31 is made of a thin, cylindrical covering covering a large number of synthetic fibers bundled together in a shaft shape, and is impregnated with ink to form an ink reservoir.

The pen shaft 32 is a shaft-shaped bundle of fibers, and the ink in the filling 31 flows forward due to its capillary force. The front end of the pen shaft 32 is wedge-shaped, and its frontmost end serves as the writing part 30a for applying ink to the surface being written on. A writing part 30a shaped like this is sometimes called a chisel tip.

The case 33 is integrally constructed from a large-diameter cylindrical padding storage section 33a that stores the padding 31, and a small-diameter cylindrical cover support section 33b that is stepped forward of the padding storage section 33a.

The padding storage section 33a contains the padding 31 and prevents it from moving back and forth. The rear end opening of this padding storage section 33a is closed by a tail-plug-shaped connecting member 36.

The connected member 36 is fixed to the rear end of the padding storage section 33a so as not to be able to rotate or move back and forth.
This connected member 36 is detachably fitted to the front end portion of the operating member 20, and prevents the core 30 from rotating by the rotation restricting portion, while holding the core 30 so that it can tilt flexibly.

The rotation regulating portion may be configured to prevent the core 30 from rotating around the axis between the operating member 20 and the core 30, and may, for example, be configured from a small recess provided on one of the connected member 36 and the operating member 20, which is recessed in a circumferential direction, and a small protrusion provided on the other of the two that fits into the small recess (not shown).
Other examples of the rotation regulating portion include a configuration in which one of the operating member 20 and the connected member 36 is formed in a rectangular column shape and the other is formed in a rectangular hole shape that fits into the one, or a configuration in which one is formed in an elliptical column shape and the other is formed in an elliptical hole shape that fits into the one.

The cover support portion 33b is a cylindrical portion that holds the pen holder 32 therein so that it cannot move back and forth.
An engaging protrusion 33b1 is provided on the outer peripheral surface of the front end of the cover support portion 33b so as to protrude radially outward in the barrel direction (see FIG. 3).

Multiple engaging protrusions 33b1 (two equally spaced apart in the illustrated example) are provided at intervals around the barrel. In the illustrated example, each engaging protrusion 33b1 is a rectangular prism-shaped protrusion.

A biasing member support portion 35b2 is provided on the rear end side of the cover support portion 33b. The biasing member support portion 35b2 is inserted into the rear end side of the biasing member 35 to support the biasing member 35.
The biasing member support portions 35b2 are a plurality of (four in the illustrated example) protrusions spaced apart in the circumferential direction.
In FIG. 3, reference numeral 35b3 denotes an air exchange hole that penetrates the cover support portion 33b in the radial direction.

The biasing member 35 is a compression coil spring, and is attached in an annular shape to the cover support portion 33b rearward of the engaging protrusion 33b1, and biases the cover member 34 forward.
The rear end of the urging member 35 is attached to the plurality of urging member support portions 35b2 in an annular shape, and the rearmost end of the urging member 35 abuts against the stepped portion at the front end of the padding storage portion 33a. The front end of the urging member 35 abuts against the rear end of the cover member 34, which will be described later.

The cover member 34 is a long, substantially cylindrical member, the front end portion of which cylindrically covers the writing portion 30a, and the rear end portion of which is fitted to the cover support portion 33b so as to be movable forward and backward.
The cover member 34 has a peripheral wall formed with a through-hole 34a through which the engaging protrusion 33b1 can be inserted so as to be movable forward and backward.

A plurality of guide holes 34a (two in the illustrated example) are provided at equal intervals in the circumferential direction of the barrel, corresponding to the plurality of engaging protrusions 33b1 of the cover support portion 33b.
Each guide hole 34a is formed in a generally rectangular shape in a plan view (see FIG. 4), and has inclined edges 34a1, 34a2 at the inner edge of its front end that are inclined relative to the circumferential direction of the barrel.

More specifically, the inner edge of the front end of the guide hole 34a is formed in a generally protruding shape (in other words, V-shaped) in plan view, with the central portion in the circumferential direction of the barrel projecting to one side in the axial direction of the barrel (to the front of the barrel, according to the example in Figure 4), and both sides of this protruding end each form an inclined edge portion 34a1 (or 34a2).

One of the inclined edges 34a1 is inclined obliquely rearward from the tip in one circumferential direction of the barrel (see FIG. 4).
The other inclined edge portion 34a2 is inclined obliquely rearward from the tip toward the other side in the circumferential direction of the barrel.

A chamfered portion 34a3 is provided on the radially outer side of each inclined edge portion 34a1 (or 34a2) (see Figure 5). This chamfered portion 34a3 is an inclined surface that slopes radially outward from the front oblique barrel. In the illustrated example, the chamfered portion 34a3 is formed as a C-chamfer, but it can also be formed as an R-chamfer or other curved surface.

Next, the characteristic functions and effects of the retractable writing instrument 1 having the above-described configuration will be described in detail.
When one of the cores 30 moves forward by pushing the operating member 20 , the front edge of the cover member 34 of this core 30 may interfere with the guide hole 34 a of the other core 30 .
In such a case, the front end edge of one core 30 is guided in one circumferential direction by the inclined edge portion 34a1 or 34a2 of the front end inner edge of the guide hole 34a of the other core 30, and is further guided radially outward by the chamfered portion 34a3.
This prevents the front end edge of the cover member 34 of one of the cores 30 from abutting against the front end inner edge of the guide hole 34a of the other core 30, thereby preventing the forward movement of the one of the cores 30 from being hindered.

Furthermore, when one of the cores 30 that has advanced moves backward, the guide hole 34a of this core 30 does not come into contact with the front edge of the cover member 34 of the other core 30, preventing its backward movement, thanks to the inclined edge 34a1, inclined edge 34a2, chamfered portion 34a3, etc. of the one of the cores 30.

In addition, the inclined edge 34a1, inclined edge 34a2, chamfered portion 34a3, etc., can prevent the guide hole 34a from interfering with, for example, a step (not shown) on the inner surface of the barrel 10 or a component (not shown) inside the barrel 10.

Therefore, with the retractable writing instrument 1 configured as described above, it is possible to prevent the retractable core from interfering with the surrounding area and causing malfunctions.

<Modification>
The retractable writing instrument 1 having the above-described configuration can be partially modified as described below.
The retractable writing instrument shown in FIG. 7 is the same as the retractable writing instrument 1 described above, except that the circumferential positions of the guide holes 34a are changed.
More specifically, each guide hole 34 a opens in a direction intersecting (orthogonal to) the direction in which the plurality of cores 30 are arranged.
Therefore, with this retractable writing implement, it is possible to more effectively prevent the guide hole 34a of one center lead 30 from interfering with the other center lead 30.

Furthermore, in the retractable writing instrument 1 configured as described above, the cover member 34 can be replaced with any of the cover members 61, 62, 63, and 64 shown in Figures 8(a) to 8(d).

The cover member 61 is similar to the cover member 34 except that inclined edges 34a1' and 34a2' and a chamfered portion 34a3' are added to the inner edge of the rear end of the guide hole 34a.
The inclined edges 34a1', 34a2' and the chamfered portion 34a3' are the same as the inclined edges 34a1, 34a2 and the chamfered portion 34a3 described above, but with the front and rear orientations reversed.
Therefore, with a retractable writing instrument equipped with this cover member 61, the guide hole 34a of one of the cores 30 that moves back and forth can be more effectively prevented from interfering with surrounding components, etc. (including the other core 30).

The cover member 62 has inclined edges 62a, 62a' and chamfered edges 62b, 62b' that are curved and continuous, formed on the inner edges of the front and rear ends of the guide hole 34a, respectively.
The front inclined edge 62a is formed in an arc shape that protrudes forward. The chamfered portion 62b is an inclined surface that extends radially outward of the front oblique barrel and is formed along the inclined edge 62a.
The rear inclined edge 62a' is also formed in an arc shape that protrudes forward. The chamfered portion 62b' is an inclined surface that extends radially outward from the rear oblique barrel, and is formed along the inclined edge 62a'.
Therefore, with a retractable writing instrument equipped with this cover member 62, the same effects as those of the retractable writing instrument 1 can be more effectively achieved.

The rear inclined edge 62a' and chamfered portion 62b' may be formed in an arc shape that protrudes rearward (i.e., in the opposite direction to the inclined edge 62a and chamfered portion 62b).

The cover member 63 has a single inclined linear inclined edge 63a, 63a' and a single chamfered edge 63b, 63b' formed on the inner edge of the front end and the inner edge of the rear end of the guide hole 34a, respectively.
In a retractable writing instrument equipped with this cover member 63, the same effects as those of the retractable writing instrument 1 can be effectively obtained.

The cover member 64 has three or more bent inclined edges 64a, 64a' and chamfered edges 64b, 64b' formed on the inner edges of the front and rear ends of the guide hole 34a, respectively.
In a retractable writing instrument equipped with this cover member 64, the same effects as those of the retractable writing instrument 1 can be effectively obtained.

Furthermore, according to the above embodiment, all of the multiple cores 30 are provided with cover members 34, but the effects of the present invention can be achieved as long as at least one of the multiple cores is provided with the cover member.
For example, one of the multiple cores may be a core 30 having a cover member 34, and the other cores may be a core for a ballpoint pen that does not have a cover member, a core for a mechanical pencil, a core for an electronic pen, etc.

Furthermore, according to the above embodiment, a retractable writing instrument 1 is constructed having multiple cores 30 within the barrel 10, but as another example, it is also possible to construct a retractable writing instrument having a single core 30 within the barrel 10.
In this retractable writing instrument, when a single core 30 is retracted, the guide hole 34a of the cover member 34 on the core 30 can be prevented from interfering with surrounding components or parts (for example, a step inside the barrel 10) and causing problems with the core 30's forward and backward movement.

Furthermore, the present invention is not limited to the above-described embodiments, and modifications can be made as appropriate without departing from the spirit of the present invention.

1: Retractable writing implement 10: Barrel 20: Operating member 30: Core 30a: Writing part 33b: Cover support part 33b1: Engagement protrusion 34, 61: Cover member 34a: Guide hole 34a1, 34a2: Sloped edge part

Claims (6)

A retractable writing instrument comprising a barrel and a core housed in the barrel, the core being adapted to protrude and retract from a front end of the barrel,
The core includes a writing portion at the front end, a cover member that cylindrically covers the writing portion and moves back and forth to expose and retract the writing portion, and a cover support portion that supports the cover member from the inside so that it can be moved back and forth,
The cover support portion is provided with an engaging protrusion that protrudes outward in the radial direction of the barrel,
The cover member is provided with a through-hole through which the engaging protrusion is inserted so as to be able to advance and retreat,
A retractable writing implement, characterized in that a chamfered portion is provided on the radially outer side of the inner edge of the front end or the inner edge of the rear end of the guide hole . The inner edge at the front end or the inner edge at the rear end of the guide hole has an inclined edge portion inclined with respect to the circumferential direction of the barrel,
2. The retractable writing implement according to claim 1, wherein the chamfered portion is provided on the radially outer side of the inclined edge portion . A retractable writing instrument as described in claim 2, characterized in that the front end inner edge or rear end inner edge of the guide hole has a shape in which the central portion in the circumferential direction of the barrel protrudes in one direction in the axial direction of the barrel, and both side portions of the tip each form the inclined edge portion . 3. The retractable writing implement according to claim 2, wherein the inner edge at the front end or the inner edge at the rear end of the guide hole is curved continuously to form the inclined edge portion . A retractable writing instrument as described in any one of claims 1 to 4, characterized in that multiple cores are provided within the barrel, and the cover member is provided on at least one of these multiple cores. The cores are provided in a plurality so as to be aligned in the axial direction of the barrel,
6. The retractable writing implement according to claim 5, wherein the guide hole is open in a direction intersecting the direction in which the plurality of cores are arranged.