JP5356969B2 - Writing instrument and core holding unit for writing instrument - Google Patents

Description

  The present invention relates to a knock-type writing instrument and a core holding unit applied to the same.

  Conventionally, as a technology in such a field, there is Japanese Patent No. 4153314. The writing instrument described in this publication has a middle piece fixed on the rear end side of the shaft tube, and a rotor for holding the middle core is inserted into the middle piece. The rotor slides in the middle piece while rotating via the cam mechanism, and the core can be projected and retracted from the tip of the writing instrument by the advance and retreat of the rotor. The rotor is biased by a spiral spring, and the spiral spring is disposed between a cylindrical receiving member fixed to the tip of the middle piece and the rotor, and one end of the spiral spring is a flange of the rotor. The other end of the spiral spring is in contact with a step formed at the tip of the receiving member. Since such components are integrated and unitized with the middle piece, the rotor, the operation unit, the helical spring, and the receiving member, the assembling workability of the writing instrument is improved.

Japanese Patent No. 4153314

  However, in the conventional writing instrument described above, the unit is made up of the middle piece, the rotor, the operation unit, the helical spring, and the receiving member, but the structure is complicated, and from the viewpoint of cost reduction and weight reduction, It has been desired to simplify the structure by reducing the number of parts.

  An object of this invention is to provide the core holding | maintenance unit and writing instrument which enabled simplification of the structure.

The present invention is a writing instrument in which the core can be freely inserted and removed from the tip of the cylindrical portion.
A core holding part that is slidable along the inner wall surface of the cylinder part and holds the core;
A helical spring that urges the core holding part toward the rear end side of the cylindrical part;
A knock part that is attached to the cylinder part and presses the core holding part against the urging force of the spiral spring;
The tube portion is formed with a claw piece bent inward as a part of the tube portion so that the tip is opposed to the tip of the core holding portion, and the tip of the claw piece and the tip of the core holding portion are And a helical spring is held.

  In this writing instrument, at the time of assembling, the spiral spring is locked at the tip of the claw piece simply by bending the claw piece inward with the core holding part and the spiral spring accommodated in the cylinder part. The spiral spring does not fall off from the tip of the part. In this way, by adopting a claw piece that can be bent inward as a part of the cylindrical portion, there is no need for a separate component that supports the spiral spring, so the structure can be simplified, and the cost and weight can be reduced. Can be planned.

The cylindrical portion includes a shaft cylinder that forms an outer shell, a cylindrical middle piece that is accommodated along the inner wall surface of the shaft cylinder, and that accommodates the core holding portion and the helical spring. It is preferable that a claw piece is formed on the outer surface of the claw piece, and a protrusion that abuts against the inner wall surface of the shaft tube is formed on the outer surface of the claw piece.
If such a configuration is adopted, the middle piece, the core holding portion, the spiral spring, and the knock portion are unitized, and when the middle piece is inserted into the shaft tube during assembly, the protrusion of the projection of the claw piece is projected to the shaft tube. Since it continues to be regulated by the inner surface, the helical spring can be reliably locked at the tip of the claw piece during or after the writing instrument is assembled, and the helical spring can be reliably prevented from falling off.

Further, it is preferable that a locking convex portion that is locked by a concave portion formed on the inner wall surface of the shaft cylinder is formed on the outer wall surface of the middle piece.
When the core holding unit is inserted along the shaft tube at the time of assembly, the locking projection of the center piece enters the recess of the shaft tube, so that the core holding unit can be easily fixed in the shaft tube with one touch. Such a configuration, combined with the use of the protrusions of the claw pieces, enables one-touch mounting in the shaft cylinder of the core holding unit, and improves assembly workability.

  The writing instrument according to the present invention is provided with the core holding unit according to any one of claims 1 to 3.

  According to the present invention, the structure can be simplified.

It is sectional drawing which shows one Embodiment of the writing instrument to which the core holding | maintenance unit which concerns on this invention is applied. It is sectional drawing which shows the writing instrument after knocking. It is sectional drawing which shows a center core holding unit. It is a perspective view which shows the state which accommodated the spiral spring in the inside piece. It is the schematic which shows a knock mechanism.

  Hereinafter, preferred embodiments of a writing instrument and a core holding unit according to the present invention will be described in detail with reference to the drawings. In the following description, the pen tip side is referred to as “front side”.

  As shown in FIG. 1, the writing instrument 1 is a knock type, and has a synthetic resin shaft cylinder (cylinder part) 2 that houses a core (refill) 3. The shaft cylinder 2 includes a shaft portion main body 2a in which a clip 4 is integrally formed, and a tip opening 2b screwed to the tip of the shaft portion main body 2a. At the rear end of the shaft tube 2, a knock cap 17 for allowing the core 3 to be taken in and out from the tip of the shaft tube 2 protrudes, and a rubber grip portion 7 is fixed to the grip portion of the shaft tube 2.

  A core holding unit 10 is loaded in the shaft body 2a of the shaft tube 2 forming the outer shell. As shown in FIG. 3, the core holding unit 10 includes a cylindrical middle piece 11 (cylinder part) fixed along the inner wall surface 2 a </ i> A of the shaft body 2 a, and the inner wall surface 11 a of the middle piece 11. A cylindrical central core holding portion 12 that is slidable and holds the rear end of the central core 3, and a spiral spring 13 that urges the central core holding portion 12 toward the rear end side of the shaft body 2a. And a knock portion 6 that is attached to the middle piece 11 and presses the core holding portion 12 against the urging force of the spiral spring 13.

  The knock portion 6 is a knock rod that protrudes from the rear end of the middle piece 11, and the rear end of the knock rod 6 is inserted into the front end side of the cylindrical knock cap 17 that protrudes from the shaft portion main body 2a to be locked. It has been made. A step portion 6 b is formed on the outer peripheral surface of the front end of the knock bar 6, a reduced diameter portion 11 e is formed at the rear end of the middle piece 11, and the step portion 6 b of the knock bar 6 is reduced in diameter portion 11 e of the intermediate piece 11. The knock bar 6 is prevented from coming off.

  The core holding unit 10 has a knock mechanism 20, and as shown in FIG. 5, the knock mechanism 20 includes an angled tooth portion 6 a that is annularly arranged at the tip of the knock bar 6 and forms an isosceles triangle, and a rotor. Formed on the inner wall 11a of the intermediate piece 11 and the protrusion 21 protruding radially from the peripheral surface of the core holding part 12 rotating in the circumferential direction in the intermediate piece 11, the end of the protrusion 21 is The two-step sawtooth portion 11b to be locked and the slide groove 11c formed on the inner wall surface of the intermediate piece 11 and extending in the direction of the axis L between the pair of sawtooth portions 11b. The strip 21 and the slide groove 11c are formed every 120 degrees in the circumferential direction. And the inclined surface 21a is formed in the edge part of the protruding part 21, This inclined surface 21a engages with the chevron tooth part 6a, when projecting the center core 3 from an immersion state, and the center core 3 protrudes. Sometimes it engages the sawtooth portion 11b.

  The operation of the knock mechanism 20 will be briefly described. As shown in FIG. 5A, when the knock cap 17 is pushed with a finger, the knock bar 6 moves forward, and the ridge portion 21 near the top of the chevron tooth portion 6a. When the inclined surface 21a is pushed, the core holding part 12 moves forward. At this time, the protrusion 21 slides along the slide groove 11c. Then, as shown in FIG. 5B, when the knock cap 17 is continuously pressed, the ridge portion 21 is detached from the slide groove 11 c, and the inclined surface 21 a of the ridge portion 21 is angled by the urging force of the spiral spring 13. It moves slightly along the slope of 6a, and accordingly, the core holding part 12 is slightly rotated.

  Thereafter, as shown in FIG. 5 (c), when the finger is released from the knock cap 17, the protrusion 21 is retracted by the urging force of the spiral spring 13. At this time, the inclined surface 21a of the protrusion 21 is engaged with the top of the upstream sawtooth portion 11b, and the inclined surface 21a of the protrusion 21 moves along the inclined surface of the upstream sawtooth portion 11b. Accordingly, the core holding part 12 rotates. Then, the inclined surface 21a of the ridge portion 21 is engaged with the valley portion 11f between the sawtooth portions 11b, whereby the rotation and retraction of the core holding portion 12 are stopped. As a result, as shown in FIG. 2, the tip of the core 3 protrudes from the tip 2b and enters a writing state.

  As shown in FIG. 5D, when the knock cap 17 is pushed from the written state, the inclined surface 21a of the protruding portion 21 is pushed in the vicinity of the top of the chevron tooth portion 6a, so that the core holding portion 12 moves forward. . At this time, the protrusion 21 slides along the upright surface 11d between the sawtooth portions 11b. When the knock cap 17 is kept pressed, the protrusion 21 is disengaged from the sawtooth portion 11b, and the inclined surface 21a of the protrusion 21 is slightly moved along the slope of the angle tooth portion 6a by the biasing force of the spiral spring 13. Accordingly, the core holding part 12 is slightly rotated.

  Thereafter, when the finger is released from the knock cap 17, the protruding portion 21 is retracted by the biasing force of the spiral spring 13. At this time, the inclined surface 21a of the ridge portion 21 is engaged with the top of the downstream sawtooth portion 11b, and the inclined surface 21a of the ridge portion 21 moves along the inclined surface of the downstream sawtooth portion 11b. Accordingly, the core holding part 12 rotates. And the core holding | maintenance part 12 reverse | retreats because the protrusion part 21 falls in the next slide groove 11c. Thereby, as shown in FIG. 1, the front-end | tip of the center core 3 enters in the front opening 2b.

  Such a knock mechanism 20 is known from Japanese Patent No. 4153314.

  As shown in FIGS. 3 and 4, the cylindrical middle piece 11 is formed with a claw piece 23 positioned in front of the core holding portion 12. The claw pieces 23 are provided every 180 degrees in the circumferential direction of the middle piece 11, and the claw pieces 23 extending in the direction of the axis L are produced by forming a U-shaped slit 24 in the middle piece 11 at the time of injection molding. It is. The tip 23 a of each claw piece 23 faces the tip 12 a of the core holding part 12, and the end of the spiral spring 13 is held by the tip 23 a of the claw piece 23 and the tip 12 a of the core holding part 12. Such a claw piece 23 forms a part of the middle piece 11 and is bent in a “<” shape toward the inside from a state extending along the axis L.

  In assembling such a core holding unit 10, first, the knock bar 6 is inserted from the front end opening of the center piece 11, and then the core holding part 12 is inserted. After that, the spiral spring 13 is inserted, and a flat spring push rod 26 is inserted from the front end opening of the middle piece 11 so that the spiral spring 13 is compressed. Thereafter, the tip 23 a of the claw piece 23 is inserted into the middle piece 11 so that the claw piece 23 is bent in a “<” shape. In this way, the spiral spring 13 is locked at the tip 23 a of the claw piece 23 only by bending the claw piece 23 in the shape of “<”, and the spiral spring 13 is thereby locked from the opening of the tip of the middle piece 11. Will not fall out. When a claw piece 23 that can be bent inward is used as a part of the middle piece 11, no additional parts for supporting the spiral spring 13 are required, so that the structure can be simplified and the cost and weight can be reduced. it can.

  Further, on the outer surface of the claw piece 23, a hemispherical protrusion 23b that abuts against the inner wall surface 2aA of the shaft tube 2 is formed. Accordingly, when the core holding unit 10 is inserted into the shaft cylinder 2, the protrusion 23b of the claw piece 23 continues to be restricted by the inner wall surface 2aA of the claw piece 2, so that the claw piece is assembled during or after the writing instrument 1 is assembled. Thus, the helical spring 13 can be reliably kept locked at the tip 23a of the 23, and the falling of the helical spring 13 can be reliably prevented.

  Further, two ring-shaped locking projections 28 are formed on the outer wall surface of the middle piece 11, and the locking projections 28 are fitted and locked on the inner wall surface 2aA of the shaft cylinder 2. A ring-shaped recess 27 is formed. Accordingly, when the core holding unit 10 is inserted along the shaft cylinder 2, the locking projection 28 of the center piece 11 enters the recess 27 of the shaft cylinder 2, so that the core holding unit 10 can be touched in the shaft cylinder 2 with one touch. Can be fixed easily. Such a configuration, combined with the use of the protrusion 23b of the claw piece 23, enables one-touch mounting in the shaft cylinder 2 in the core holding unit 10 and improves assembly workability.

  It goes without saying that the present invention is not limited to the embodiment described above. For example, as the cylinder part, there are the shaft cylinder 2 and the middle piece 11, and the claw piece 23 may be provided in any of them. The claw piece 23 may be brazed in advance in a “<” shape. The number of the claw pieces 23 may be one or more. The shape of the protrusion 23b may not be a hemisphere, but may be a conical shape, a ridge shape, or the like.

  DESCRIPTION OF SYMBOLS 1 ... Writing instrument, 2 ... Shaft cylinder (cylinder part), 3 ... Center core, 6 ... Knock stick (knock part), 10 ... Center core holding unit, 11 ... Center piece (cylinder part), 12 ... Center core holding part, DESCRIPTION OF SYMBOLS 13 ... Spiral spring, 23 ... Claw piece, 23b ... Projection part, 27 ... Concave part, 28 ... Locking convex part.

Claims (4)

In a writing instrument that allows the center core to be inserted and removed freely from the tip of the cylinder,
A core holding part that is slidable along the inner wall surface of the cylindrical part and holds the core; and
A helical spring that urges the core holding portion toward the rear end of the cylindrical portion;
A knock part that is attached to the cylinder part and presses the core holding part against the urging force of the spiral spring;
The tube portion is formed with a claw piece bent inward as a part of the tube portion so that the tip is opposed to the tip of the core holding portion, and the tip of the claw piece and the core A core holding unit for a writing instrument, wherein the spiral spring is held by a tip of a holding part.   The cylinder part is composed of a shaft cylinder that forms an outer shell, a cylindrical middle piece that is accommodated along the inner wall surface of the shaft cylinder, in which the core holding part and the spiral spring are accommodated, 2. The writing instrument according to claim 1, wherein the claw piece is formed on the middle piece, and a protruding portion that is in contact with an inner wall surface of the shaft cylinder is formed on an outer surface of the claw piece. Core holding unit.   3. The core holding unit for a writing instrument according to claim 2, wherein a locking convex portion that is locked by a concave portion formed on the inner wall surface of the shaft cylinder is formed on the outer wall surface of the middle piece.   A writing instrument provided with the core holding unit according to any one of claims 1 to 3.

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