JP2016036949A - Lead core delivery mechanism and mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead core delivery mechanism and a mechanical pencil which are hard to generate malfunction.SOLUTION: A lead core delivery mechanism is equipped with a chuck 32b which advances a gripped lead core and releases the lead core and a core breaker 32d which holds the lead core 31 inserted into the chuck 32b at a position separated forward from the chuck 32b, and delivers the lead core 31 to the front side of the core breaker 32d by gripping and releasing, and advance/retreat movement of the chuck 32b. In the lead core delivery mechanism, a slide cylinder 32e which advances and retracts in the state that an outer periphery of the lead core 31 is covered between the chuck 32b and the core breaker 32d, and a slide cylinder energization member 32f which energizes the slide cylinder 32e backward relatively to the core breaker 32d are provided, whereby the chuck 32b and the slide cylinder 32e are integrally advanced and retracted. Further, an outer peripheral surface of the slide cylinder 32e is provided with a lead powder relief groove 32e2 which penetrates the slide cylinder in an axial direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lead lead feeding mechanism and a mechanical pencil provided in a mechanical pencil, a composite writing instrument, or the like that feeds a lead lead by a knocking operation, a shaft swinging operation, or the like.

Conventionally, in this kind of invention, as described in Patent Document 1, a chuck (core clamping chuck 22) that advances and releases a sandwiched lead core and lead inserted into the chuck (22). The outer periphery of the lead core was covered between the core breaker (core holder 32) for holding the core at a position away from the chuck (22) and the chuck (22) and the core breaker (32). There is a mechanical pencil including a guide pipe (34) having a three-end tip that advances and retreats in a state and a tip (16) in which these guide pipes are contained.
According to this mechanical pencil, the guide pipe (34) protects the core portion ahead of the chuck (22), and therefore, in the space between the chuck (22) and the core breaker (32). It is possible to reduce the occurrence of core breakage.

However, according to the prior art, the core powder generated by friction with the guide pipe (34) is between the outer periphery on the rear end side of the guide pipe (34) and the inner peripheral surface of the tip (16). There is a risk of malfunction due to entering and fixing.
Furthermore, since the guide pipe (34) is formed in a three-end shape, the lead core that has received a strong impact such as a drop impact, for example, is sandwiched between the three-shaped portion so that the core breaks or operates. There is also a risk of failure.

JP 2003-54184 A

  This invention is made | formed in view of the said conventional situation, The process made into the subject is providing the lead core feeding mechanism and mechanical pencil which are hard to produce a malfunctioning.

  One means for solving the above problems includes a chuck for advancing and releasing the sandwiched lead core, and a core breaker for holding the lead core inserted through the chuck in a position away from the chuck, In a lead lead feeding mechanism that feeds a lead lead forward of the lead breaker by clamping, releasing, and advancing and retracting the chuck, the outer periphery of the lead lead is covered between the chuck and the lead breaker. By providing a slide cylinder that advances and retreats and a biasing member that urges the slide cylinder toward the back relative to the core breaker, the chuck and the slide cylinder advance and retreat integrally, and the outer periphery of the slide cylinder The surface is provided with a core powder relief groove penetrating in the axial direction.

  Since the present invention is configured as described above, it is difficult to cause malfunction.

It is sectional drawing which shows an example of the writing instrument which concerns on this invention. It is a principal part expansion perspective view of the writing instrument. It is a half sectional view showing an example of a slide cylinder. It is the figure which looked at the same slide cylinder from the front. It is a half sectional view showing the state where the writing core was removed from the holder. (A1) is an end view taken along line (a1)-(a1) in FIG. 5, and (a2) is an end view taken along line (a2)-(a2) in FIG. It is a top view which shows the engagement relation of an advancing / retreating member and a shaft cylinder. It is the front end side expanded sectional view of the writing instrument, (a) shows a normal writing state, (b) shows the state which the holder advanced. In this figure, only the part moved with respect to (a) is hatched and shown in (b). It is a whole sectional view showing the state where the holder advanced about the writing instrument. It is principal part sectional drawing of the writing instrument, (a) shows a normal state, (b) shows the state by which the writing core was pushed back. In this figure, only the part moved with respect to (a) is hatched and shown in (b). It is sectional drawing which shows the modification of a cam slope in each of (a)-(c). It is a front end side expanded sectional view which shows the other examples of the writing instrument which concerns on this invention, (a) shows a normal writing state, (b) shows the state which the holder advanced. In this figure, only the part moved with respect to (a) is hatched and shown in (b). It is principal part sectional drawing which shows the other example of the writing instrument which concerns on this invention. It is principal part sectional drawing which shows the other example of the writing instrument which concerns on this invention.

The first feature of the present embodiment includes a chuck that advances and releases the sandwiched lead core, and a core breaker that holds the lead core inserted through the chuck in a position away from the chuck, In a lead lead feeding mechanism that feeds a lead lead forward of the lead breaker by clamping, releasing, and advancing and retracting the chuck, the outer periphery of the lead lead is covered between the chuck and the lead breaker. By providing a slide cylinder that advances and retreats and a biasing member that urges the slide cylinder toward the back relative to the core breaker, the chuck and the slide cylinder advance and retreat integrally, and the outer periphery of the slide cylinder A core powder relief groove penetrating in the axial direction was provided on the surface.
According to this configuration, it is possible to prevent the lead core from being broken due to a drop impact or the like between the chuck and the core breaker by the slide cylinder, and the core powder generated by sliding of the slide cylinder can be prevented. Since the core powder is released in the axial direction of the slide cylinder by the core powder escape groove, it is possible to prevent the core powder from being fixed around the slide cylinder and causing malfunction.

As a second feature, the inner peripheral surface of the slide cylinder is formed into a cylindrical shape that is continuous over the entire circumference and that is close to or in contact with the outer peripheral surface of the lead core.
According to this configuration, in order to cover and protect the outer peripheral surface of the slide cylinder in a cylindrical shape over the entire circumference, for example, the inner periphery of the slide cylinder is broken or lead-cored compared to a structure having irregularities and grooves. Less likely to cause wear.

The third feature is that the chuck, the core breaker, the urging member, and a holding cylinder containing the slide cylinder are provided, and the slide cylinder has an outer peripheral surface having the core powder escape groove inside the holding cylinder. Advancing and retreating by sliding on the peripheral surface.
According to this configuration, the core powder can be released in the axial direction by the core powder relief groove between the outer peripheral surface of the slide cylinder and the inner peripheral surface of the holding cylinder, and the slide cylinder slides on the inner peripheral surface of the holding cylinder. Good mobility.

As a fourth feature, the slide cylinder has a diameter-expanded portion whose diameter on the rear side is larger than that on the front side, and the core powder escape groove is formed on the outer peripheral surface of the diameter-expanded portion.
According to this structure, the effect | action which releases a lead core to an axial direction by a core powder escape groove | channel can be exhibited effectively.

  As a fifth feature, a mechanical pencil was configured by including the lead core feeding mechanism having the above-described configuration.

Next, a preferred embodiment having the above features will be described in detail with reference to the drawings.
In addition, in this specification, a shaft cylinder axial direction means the direction where the centerline of a shaft cylinder extends. “Front” means one side of the axial direction of the cylinder and the tip direction of the writing portion. Further, “rear” means a direction opposite to the one side in the axial direction of the shaft cylinder. The “axial cylinder radial direction” means a direction orthogonal to the axial cylinder axis direction. Further, the “outward direction of the shaft tube diameter” means a direction away from the center of the shaft tube along the shaft tube diameter direction. The “inner cylinder radial direction” means a direction approaching the center of the axial cylinder along the axial cylinder radial direction.

As shown in FIGS. 1 and 2, the writing instrument 1 includes a shaft tube 10, a holder 20 that is inserted through the front opening 11 a of the shaft tube 10 and protrudes forward from the front end of the shaft tube 10, A lead core 31 is inserted into the holder 20 so as to protrude forward from the front end of the holder 20, and a writing core support portion 32g20 of the writing core 30 abuts from behind and can move forward and backward by a predetermined amount relative to the shaft tube 10. And a writing core urging member 50 that urges the advancing / retreating member 40 forward with respect to the shaft tube 10.
In the present embodiment, the writing core 30 is composed of a plurality of members including the lead core 31, and does not show only the lead core 31.

According to the illustrated example, the shaft tube 10 is formed by connecting and fixing the rear shaft tube 12 to the rear end side of the front shaft tube 11 by connecting means such as screwing, fitting, and adhesion, and tapering the front end side. It is formed in a substantially long cylindrical shape.
Other examples of the shaft cylinder 10 may include an aspect composed of a single cylinder, an aspect in which a separate tip is connected to the distal end side of the cylinder, and an aspect composed of three or more cylinders. It is.

A front opening 11a for inserting a holder 20 (to be described later) and projecting forward is provided on the distal end side of the shaft tube 10. The front opening 11a has a smaller diameter on the inner peripheral surface of the shaft tube 10 than the rear portion, and the front end of the holder urging member 13 is received by a rear end surface inside the reduced diameter portion.
According to the illustrated example, the front opening 11a is an inner peripheral surface of a cylindrical hole substantially parallel to the axial center of the shaft, and a frictional resistance between the front end edge and the cam inclined surface 20a of the holder 20 is provided. The convex part 11b is provided in order to reduce this.

Further, on the inner peripheral surface of the shaft tube 10, an annular step portion 11 c that reduces the diameter of the front side is provided on the rear side of the holder 20 (specifically, on the rear side of the spring receiving portion 21). The step portion 11c receives a protrusion 32g21 of the writing core 30 described later from the front, and restricts the movement of the entire writing core 30 to the front.
In addition, an annular step portion 11n whose diameter is reduced on the front side is provided behind the step portion 11c on the inner peripheral surface of the shaft tube 10. The step portion 11n abuts so as to receive a front end of an advance / retreat member 40, which will be described later, from the front, and restricts the forward movement of the advance / retreat member 40.

Further, the peripheral wall of the shaft tube 10 is provided with a recess 12a that is recessed outward in the shaft tube diameter and extended in the shaft tube shaft direction, and in this recess 12a, the advancing and retracting member 40 is advanced and retracted by a predetermined amount. Are combined.
As shown in FIG. 7, the concave portion 12a is provided with a hole in a rectangular shape in plan view passing through the peripheral wall on the front end side of the peripheral wall of the rear shaft cylinder 12, and the front end side of the rear shaft cylinder 12 including the hole. Is inserted into the front shaft cylinder 11. The length of the recess 12a in the axial direction of the shaft is appropriately set so that the advance / retreat member 40 can advance and retract by a predetermined amount.

According to the illustrated example, the holder urging member 13 is a compression coil spring in which the holder 20 is loosely inserted on the center side, and urges the holder 20 backward via the spring receiving portion 21.
Other examples of the holder urging member 13 include an aspect using an elastic body such as an elastomer resin and rubber, an aspect using an elastic body such as a leaf spring, and a tension for pulling the holder urging member 13 from the rear side. It is possible to adopt a mode using a spring.

The holder 20 has a front opening through a cam inclined surface 20a on the outer periphery of the holder 20 so that the holder 20 moves forward and backward between the forward position advanced relative to the shaft 10 and the writing core 30 and the initial position before the forward movement. It is engaged with 11a (in detail, convex part 11b) so that advancement / retraction is possible.
Then, in the initial position (see FIG. 8A), the holder 20 contacts the front opening 11a of the shaft cylinder 10 with the annular cam inclined surface 20a over the entire circumference, so that the shaft cylinder is in contact with the front opening 11a. Fits immovably in the radial direction. Further, since the holder 20 has the outer diameter of the rear part of the cam inclined surface 20a smaller than the inner diameter of the front opening 11a, the front opening 11a is at the advanced position (see FIG. 8B). On the other hand, it fits in a state having play that can move in the axial direction of the shaft cylinder.
Further, a spring receiving portion 21 described later is integrally fixed to the rear end side of the holder 20. The holder 20 and the spring receiving portion 21 are urged rearward by the holder urging member 13 in the shaft cylinder 10 and are received by the buffer material 33 made of an elastic material when the holder 20 and the spring receiving portion 21 are retracted from the advance position.

More specifically, the holder 20 is a substantially cylindrical member that penetrates the front opening 11a in the front-rear direction, and is provided at the outer peripheral portion of the holder 20 at the front edge of the front opening 11a (specifically, the protrusion 11b). It has an annular cam slope 20a in sliding contact.
The cam inclined surface 20a is formed in a conical surface shape whose diameter increases toward the front, and is arranged so as to be in sliding contact with the front opening 11a (specifically, the convex portion 11b), and is applied to the holder 20 in the outer diameter direction of the shaft cylinder. The movement direction conversion mechanism is configured to move the holder 20 forward relative to the shaft tube 10 and the writing core 30 by the force of.
And the part ahead of the cam inclined surface 20a in the holder 20 is diameter-reduced according to the example of illustration.

  Further, inside the holder 20, a lead core sliding hole 20b that can slide in contact with the outer peripheral surface of the lead core 31 on the front side of the cam inclined surface 20a, and a diameter increased on the rear side of the lead core sliding hole 20b. And a writing core sliding hole 20c capable of sliding contact with the writing core 30.

  The lead core sliding hole 20 b is a hole formed with an inner diameter slightly larger than the outer diameter of the lead core 31 so as to be in contact with or close to the outer peripheral surface of the lead core 31, and extends rearward from the front end portion of the holder 20. And communicated with the writing core sliding hole 20c.

The writing core sliding hole 20c is a hole formed to have an inner diameter slightly larger than the outer diameter of the front holding portion 32g1 on the front end side of the writing core 30 so as to contact or approach the outer peripheral surface on the front end side of the writing core 30. .
In addition, although the writing core sliding hole 20c in the illustrated example is formed in a stepped shape that decreases in diameter forward along the outer peripheral surface shape of the front holding portion 32g1, as another example of the writing core sliding hole 20c, If it slides on the front end side of the writing core 30 and advances and retreats, it can also be a cylindrical shape without steps.

  The holder 20 having the above configuration is engaged with the front opening 11a of the shaft tube 10 through the outer cam inclined surface 20a so as to be able to advance and retreat, and is inserted into the shaft tube 10. In the shaft tube 10, a spring receiving portion 21 is connected and fixed to the outer peripheral surface on the rear end side of the holder 20 by connection means such as fitting.

The spring receiving portion 21 is a cylindrical member having an outer diameter larger than the outer diameter on the rear end side of the holder 20 and having a gap with respect to the inner peripheral surface of the shaft tube 10. It abuts against the rear end of the holder urging member 13 and is urged rearward by the holder urging member 13 and is received by the cushioning material 33 from the rear side.
The spring receiving portion 21 can be slightly inclined with respect to the axial center of the shaft due to the gap (see FIG. 9).

  A plurality of protrusions 21a that protrude rearward of the shaft cylinder and partially press the cushioning material are provided at the rear end portion of the spring receiving portion 21 at regular intervals in the circumferential direction (FIGS. 5 and 6 (a1)). reference).

  The buffer material 33 is an annular member made of an elastic material such as rubber or elastomer resin, and is annularly fitted to the outer periphery of a holding cylinder 32g, which will be described in detail later. It is sandwiched between the front end surface of the support portion 32g20 and elastically deformed.

In the illustrated example, the cushioning material 33 uses an O-ring of the above material as a particularly preferable embodiment, but as another example, a sponge-like synthetic resin foam or the like can also be used.
Furthermore, as another example of the buffer material 33, a coil spring having a lower elasticity than the holder urging member 13 may be used.

  The writing lead 30 is a mechanical lead for a mechanical pencil having a lead lead 31 and a lead lead feeding mechanism 32 that holds the lead lead 31 so that the lead lead 31 can be drawn out, and the lead lead 31 drawn out is inserted into the holder 20. It is arranged in the shaft cylinder 10.

  The lead core 31 is a well-known lead pencil for a mechanical pencil having a long cylindrical shape.

  The lead lead feeding mechanism 32 includes a lead lead 31 and a lead tank 32a that is held so as to advance and retreat by a predetermined amount within the shaft tube 10 and a lead lead 31 that is connected to and held by the front end of the lead tank 32a. The chuck 32b that is released, the clutch ring 32c that is fitted to the chuck 32b so as to be disengaged rearward, the core breaker 32d that holds the lead core loosely in front of the chuck 32b, and the chuck 32b and the core breaker 32d And a slide cylinder 32e that can move forward and backward with the lead core 31 inserted, a slide cylinder urging member 32f that urges the slide cylinder 32e rearward, these chuck 32b, clutch ring 32c, core A holding cylinder 32g including a breaker 32d, a slide cylinder 32e, a slide cylinder urging member 32f, and the like, and a core tongue for the holding cylinder 32g 32a a and a lead tank biasing member 32h for biasing rearwardly.

The lead tank 32 a is formed in a long cylindrical shape that can accommodate a plurality of lead leads 31, and the rear end thereof is disposed near the rear end opening of the shaft tube 10. The core tank 32a is molded from a synthetic resin material so that it can be elastically bent.
Connected to the rear end of the lead tank 32a is a lead lead introduction pipe 32i for guiding the lead lead 31 from the rear of the shaft cylinder 10 into the lead tank 32a. An eraser 32j for closing the rear end opening of the lead core introduction pipe 32i and a knock cap 32k for covering the eraser 32j from the rear are detachably connected to the rear side of the lead core introduction pipe 32i. Yes. The rear end side of the knock cap 32k protrudes rearward from the rear end of the shaft tube 10 so that a knock operation is possible.

A connecting member 32m is integrally connected to the front end of the core tank 32a.
The connection member 32m is a substantially cylindrical member that is fixed to the front end of the lead tank 32a and is inserted through the lead lead 31. The rear end side of the chuck 32b is fixed to the front end of the connection member 32m, and the flange portion on the center side in the front-rear direction Thus, the rear end of the lead tank biasing member 32h is received.
As another example, the connecting member 32m is omitted, the rear end side of the chuck 32b is directly connected to the front end side of the lead tank 32a, and the rear end of the lead tank biasing member 32h is connected to the front end edge of the lead tank 32a. It is also possible to adopt a configuration that receives directly by.

The chuck 32b is made of a synthetic resin material or a metal material that can be elastically bent, and a plurality of (for example, about 2 to 4) claws arranged concentrically so as to be located around the lead core 31 The lead core 31 is clamped so as not to be retractable by bending the claw portions inwardly in the axial diameter of the shaft, and the lead core 31 is released by elastically restoring the claw portions.
The front end side portion of the chuck 32b including the claw portion is inserted into the holding cylinder 32g. As for the front-end side of the said nail | claw part, the outer diameter part is diameter-expanded rather than the rear side part.

The clutch ring 32c is a substantially cylindrical member, and is engaged so as to advance and retract by a predetermined amount with respect to an inner peripheral surface of a holding cylinder 32g described later.
The clutch ring 32c is fitted to the plurality of claw portions of the chuck 32b from the rear side, holds the plurality of claw portions in a closed state, and is engaged with the holding cylinder 32g when the clutch ring 32c moves forward with the chuck 32b. Thus, the plurality of claw portions are relatively disengaged rearward.
The chuck 32b and the clutch ring 32c can have a well-known structure.

  The core breaker 32d is a cylindrical member made of an elastic body such as synthetic rubber or elastomer resin. The core breaker 32d is fitted in the front end side of the holding cylinder 32g so as not to move forward and backward, and elastically holds the lead core 31 inserted through the inside. To do.

The slide cylinder 32e is a substantially cylindrical member that receives the rear end of the slide cylinder urging member 32f by the stepped portion on the outer peripheral surface and loosely inserts the lead core 31 in the center, and is rearward by the slide cylinder urging member 32f. And is in contact with the front end of the chuck 32b. The inner peripheral surface of the slide cylinder 32e has a cylindrical shape that is continuous over the entire circumference, and has an inner diameter that is close to or in contact with the outer peripheral surface of the lead core 31.
The rear end side of the slide cylinder 32e is larger in diameter than the front side thereof, and a core powder escape groove 32e2 for releasing the core powder is formed in the enlarged diameter portion 32e1.

The core powder escape groove 32e2 is continuous in the axial direction so as to penetrate the peripheral wall of the enlarged diameter portion 32e1 in the axial direction. As shown in FIG. 4, the circumferential distance of the slide cylinder 32e is spaced at a constant interval. A plurality are provided. The width and depth of the slide cylinder 32e are appropriately set so as to move the core powder in the axial direction.
Between the core powder escape grooves 32e2 adjacent to each other in the circumferential direction, it is formed in a vertical rib shape, and a chamfered portion 32e11 that is inclined in the front diagonal axis direction is provided on the front end side of the vertical rib-shaped portion. The chamfered portion 32e11 reduces the frictional resistance with the inner peripheral surface of the holding cylinder 32g when the slide cylinder 32e advances and retreats. Further, the front end surface of the enlarged diameter portion 32e1 functions as a receiving portion that receives the rear end seat portion of the slide tube urging member 32f.
Further, in FIG. 3, reference numeral 32e3 is a rib fitted to the rear end side inner peripheral surface of the slide cylinder urging member 32f.

The slide cylinder urging member 32f is a compression coil spring positioned annularly around the lead core 31, and has a front end locked in the holding cylinder 32g and a rear end in contact with the slide cylinder 32e.
Other examples of the slide cylinder urging member 32f may be an elastic body made of an elastomer resin or rubber, or a tension spring that pulls the slide cylinder 32e backward.

The holding cylinder 32g is integrally formed of a front holding part 32g1 inserted into the holder 20 so as to be able to advance and retreat, and a rear holding part 32g2 integrally connected to the rear end side of the front holding part 32g1.
In the present embodiment, as a mode with particularly good productivity, the holding cylinder 32g is constituted by a plurality of members as described above. However, as another example, these can be constituted by integral members.

The front holding portion 32g1 is formed in a substantially cylindrical shape having a stepped portion whose diameter is reduced on the front side, and the outer peripheral surfaces of the front end side and the rear end side are respectively brought into sliding contact with the inner surface of the holder 20 so that the writing core slide of the holder 20 It is inserted into the moving hole 20c.
Inside the front holding portion 32g1, the front end side of the chuck 32b, the clutch ring 32c, the core breaker 32d, the slide cylinder 32e, and the slide cylinder urging member 32f are inserted.
A rear contact portion 32g11 that receives the clutch ring 32c from the rear side and a front contact portion 32g12 that receives the clutch ring 32c when moved forward from the front side are provided on the inner peripheral surface of the front holding portion 32g1. It is done. According to the illustrated example, the rear contact portion 32g11 is a front end portion of the rear holding portion 32g2. The front contact portion 32g12 is a stepped portion formed by reducing the diameter of the front side of the front holding portion 32g1.

Inside the rear holding portion 32g2, the proximal end side of the chuck 32b is fixed on the front side, and the front end side of the connection member 32m is inserted on the rear side so as to be able to advance and retreat.
In addition, the front end portion of the rear holding portion 32g2 is connected and fixed to the front holding portion 32g1, and the rear end portion of the rear holding portion 32g2 receives the front end of the core tank biasing member 32h.

  Further, a writing core support 32g20 protruding in the radially outward direction is integrally connected to the outer peripheral portion on the rear side of the rear holding portion 32g2, and the above-described cushioning material 33 is provided in front of the writing core support 32g20. It is fitted in a ring.

The writing core support portion 32g20 can be finely moved backward and in the axial direction of the shaft cylinder in a state where the writing core support portion 32g20 is in contact with the stepped portion 11c and the writing core support inclined surface 41.
More specifically, the writing core support portion 32g20 includes a protrusion 32g21 capable of coming into contact with the stepped portion 11c in the shaft tube 10 from the rear, and a writing core support inclination of the advance / retreat member 40 on the rear side of the protrusion 32g21. A contact portion 32g22 that can contact the surface 41 from the front side.

The protrusion 32g21 is engaged with the shaft cylinder 10 so that the writing core 30 cannot move forward with respect to the shaft cylinder 10 and moves in the axial cylinder radial direction by tilting as the holder 20 advances.
Specifically, as shown in FIGS. 2 and 6 (a2), a plurality of protrusions 32g21 are provided on the outer peripheral portion of the rear holding portion 32g2 at intervals in the axial direction of the shaft cylinder (4 according to the illustrated example). One) provided. Each protrusion 32g21 protrudes outward from the shaft cylinder diameter. Between the inner peripheral surface of the shaft cylinder 10 and each projection 32g21, a gap that allows the writing core 30 to move in the shaft cylinder radial direction is secured. That is, the plurality of protrusions 32g21 have an outer diameter set smaller than the inner diameter of the shaft tube 10.

  Further, the abutting portion 32g22 is provided integrally with the projection 32g21 on the rear side of the projection 32g21, and is formed in a convex curve shape that slidably contacts a writing core support inclined surface 41 at the front end of the advance / retreat member 40 described later.

  Therefore, according to the said structure, as shown in FIG. 9, the whole writing core 30 can rotate the front side part to one side of a shaft cylinder radial direction by using the protrusion 32g21 and the contact part 32g22 as a fulcrum. In this rotation, the rear portion of the fulcrum rotates to the opposite side of the axial cylinder radial direction.

  Furthermore, according to the writing core support portion 32g20 having the above-described configuration, each of the plurality of protrusions 32g21 locally presses the buffer material 33, so that the elastic deformation of the buffer material 33 at the pressed portion can be relatively large. it can.

Further, the advance / retreat member 40 is a substantially cylindrical member into which the writing instrument 1 is loosely inserted into the center side thereof. Near the inner diameter of the front end surface of the advance / retreat member 40, a writing core support inclined surface 41 is formed that expands in a substantially conical shape toward the front.
The writing core support inclined surface 41 is in sliding contact with the contact portion 32g22 on the lead core feeding mechanism 32 side to facilitate the tilting movement of the holder 20 and the lead core feeding mechanism 32.

Further, a step portion 42 that receives the front end of the writing core biasing member 50 is provided on the outer peripheral surface of the advance / retreat member 40, and can be moved forward and backward with respect to the recess 12 a on the shaft tube 10 side behind the step portion 42. An engaging protrusion 43 to be engaged is provided. The step 42 is an annular step that expands the diameter of the front side.
A plurality (two in the illustrated example) of the engagement protrusions 43 are provided so as to correspond to the plurality of recesses 12a on the shaft tube 10 side, respectively. As shown in FIG. 7, each engagement protrusion 43 is provided on an inner portion of a U-shaped notch formed on the peripheral wall of the advance / retreat member 40. According to this configuration, the engagement protrusion 43 can be flexibly elastically bent in the axial direction of the shaft cylinder, and as a result, the advance / retreat member 40 is inserted into the rear side shaft cylinder 12 as shown in FIG. The operation | work which latches the engagement protrusion 43 in the recessed part 12a can be made easy.
Each engagement protrusion 43 can move in the front-rear direction within the recess 12a, and is normally held near the front end in the recess 12a by a biasing force of a writing core biasing member 50 described later.

The writing core urging member 50 is annularly attached to the outer peripheral portion of the advance / retreat member 40, and its front end is brought into contact with the step portion 42 on the outer periphery of the advance / retreat member 40, and its rear end is a step that is the front end of the rear shaft cylinder 12. The advancing / retracting member 40 is urged forward by contacting the portion 12b.
The resilience of the writing core urging member 50 is appropriately set so that the writing core 30 is retracted by a backward force exceeding a predetermined writing pressure.

  The writing instrument 1 is provided with the four urging members described above. The urging forces of these urging members are, in ascending order, the slide cylinder urging member 32f, the holder urging member 13, and the writing core urging member 50. The lead tank biasing member 32h is provided.

Next, the characteristic effect of the writing instrument 1 having the above configuration will be described in detail.
First, in order to make the lead core 31 protrude, when a pressing force is applied to the knock cap 32k, the holding cylinder 32g brings the writing core support portion 32g20 into contact with the step portion 11c so that it cannot move forward. As the lead 32a moves forward, the chuck 32b moves forward with the lead core 31 held therebetween, the front end side of the lead core 31 is elastically held by the lead breaker 32d, and the clutch ring 32c is held in the holding cylinder 32g ( Specifically, the chuck 32b is released to the outer side of the shaft cylinder diameter by being locked by the front contact portion 32g12) and released.
And if the said pressing force is removed, the chuck | zipper 32b will reverse | retreat and will become narrow by fitting in the clutch ring 32c, and will pinch the lead core 31 again. These operations are repeated by the knock operation, and the lead core 31 moves forward and protrudes from the front end of the holder 20.

When the chuck 32b moves forward, the slide cylinder 32e that is pushed by the chuck 32b to cover and protect the lead core 31 also moves forward against the urging force of the slide cylinder urging member 32f.
The portion of the lead core 31 between the core breaker 32d and the slide cylinder 32e is covered and protected by the slide cylinder 32e, so that the lead core 31 is broken by the dropping of the writing instrument 1 or the like, It is possible to prevent the lead lead or the like that has become clogged between the lead breaker 32d and the chuck 32b.

Further, when the chuck 32b and the slide cylinder 32e are repeatedly advanced and retracted, some core powder may be generated due to the sliding contact between the chuck 32b and the slide cylinder 32e and the lead core 31, and this core powder is generated by the slide cylinder 32e. Without being accumulated in the outer peripheral portion of the slide cylinder 32e, the core powder escape groove 32e2 on the outer periphery of the slide cylinder 32e is released forward or rearward in the axial direction. Therefore, it is possible to prevent the core powder from adhering to the outer periphery of the slide cylinder 32e and hindering the advance / retreat operation of the slide cylinder 32e or the advance / retreat operation of the chuck 32b that pushes the slide cylinder 32e. Can do.
It is expected that the core powder will eventually be discharged to the front of the holder 20 together with the lead core 31 through the gap around the outer periphery of the lead core 31.

Further, in a normal writing state in which the shaft tube 10 is inclined and pressed against the writing surface P, as shown in FIG. 8A, the lead core 31 of the writing core 30 protruding forward from the holder 20 is covered. A reaction force (writing pressure) is applied from the writing surface P in the direction intersecting the lead core 31 (in other words, the axial direction of the tube cylinder). At this time, if the reaction force is larger than the normal writing pressure range, the holder 20 receives the reaction force and causes the cam inclined surface 20a of the holder 20 to move toward the front opening 11a (specifically, the convex portion 11b). It moves forward against the urging force of the holder urging member 13 while being moved in the outer diameter direction of the shaft cylinder. During this advancement, the writing core 30 including the lead core 31 moves in the axial cylinder radial direction so as to be inclined together with the holder 20 and the lead core feeding mechanism 32.
And the front end side of the lead core 31 which comprises the writing core 30 is covered and protected by the holder 20 which advanced (refer FIG.8 (b)).

When the lead core 31 is separated from the writing surface P and the reaction force is removed, the holder 20 is retracted by the urging force of the holder urging member 13 and returned to the initial position.
During the retreat, the spring receiving portion 21 integral with the holder 20 makes the rear end abut against the cushioning material 33. Since the cushioning material 33 is received by the writing core support portion 32g20 from the rear side, it elastically contracts. For this reason, the impact sound at the time of the holder 20 contacting the front side opening part 11a of the axial cylinder 10 can be relieved.
Moreover, during the retreat, the spring receiving portion 21 causes the protrusions 21 a that are divided and arranged in the circumferential direction to abut against the cushioning material 33. In addition, the writing core support portion 32g20 also presses the protrusion 32g21 divided in the circumferential direction against the cushioning material 33. Therefore, the shock absorbing material 33 can be greatly contracted locally in the circumferential direction, and the impact sound can be effectively reduced.

Other examples include a configuration in which a projection other than the illustrated example is in contact with the buffer material 33, a configuration in which the projection 21a and the projection 32g21 are omitted, and a flat surface is in contact with the buffer material 33. It is also possible.
Further, the biasing force of the holder biasing member 13 is such that the holder 20 does not move forward with a normal pen pressure with respect to the lead core 31 and the lead core 31 is broken due to the pen pressure with respect to the lead core 31. The holder 20 is appropriately set so as to move forward.

Further, the movement of the entire writing core 30 at the time of forward movement will be described. As shown in FIG. 9, the writing core 30 has a front portion with a protrusion 32g21 and an abutting portion 32g22 as fulcrums, as shown in FIG. While rotating one side (upward according to FIG. 9), the rear side portion (core tank 32a, etc.) is rotated to the other side in the axial cylinder radial direction.
The lead tank 32a is elastically bent by bringing the lead lead introduction tube 32i on the rear end side into contact with the inner peripheral surface of the shaft cylinder. By such rotation of the writing core 30 as a whole, the holder 20 is tilted and moved forward while smoothly moving in the radially outward direction.
During the rotation, the range in the axial direction from the holder 20 to the connection member 32m is maintained substantially linear. For this reason, the said range does not bend and the lead core 31 does not break. Further, as shown in FIG. 9, the portion of the lead core 31 that protrudes rearward from the connection member 32m is located in a space in the core tank 32a having a larger inner diameter than the connection member 32m. There is no breakage due to contact with the inner peripheral surface.

Next, the operation when the lead core 31 receives a pressing force in the axial direction of the cylinder will be described in detail.
When the protruding lead core 31 is strongly pressed perpendicularly to the writing surface P and the lead core 31 receives a backward pressing force, as shown in FIGS. 1 and 10 (a) and 10 (b). In addition, the pressing force is first applied to the chuck 32b holding the lead core 31 so as not to be retracted. The pressing force applied to the chuck 32b is transmitted to the advance / retreat member 40 via the clutch ring 32c, the holding cylinder 32g, etc., and the advance / retreat member 40 moves backward against the urging force of the writing core urging member 50.
Therefore, as shown in FIG. 10, the lead core 31 is immersed in the holder 20 and is free from damage caused by the pressing force.

  In addition, according to the said Example, although the cam inclined surface 20a of the holder 20 was made into the inclined surface of a cross-sectional linear shape, as another example of a cam inclined surface, an inclined surface of a cross-sectional convex curved surface shape (refer Fig.11 (a)), An inclined surface having a concave curved cross section (see FIG. 11B), an intermittent inclined surface (see FIG. 11C), or the like can be used.

  Next, a modification of the characteristic part in the writing instrument according to the present invention will be described. In addition, since the modification shown below changes a part with respect to the said writing instrument 1, it mainly demonstrates the changed part in detail, and about the part substantially the same as the writing instrument 1, is the same as the writing instrument 1. The detailed description which attaches | subjects a code | symbol and overlaps is abbreviate | omitted.

The writing instrument 2 shown in FIGS. 12 (a) and 12 (b) is provided with a cam slope 11a ′ at the front opening of the shaft tube 10 ′. The cam inclined surface 11a 'constitutes a motion direction conversion mechanism that slides the holder 20' forward by a force in the outer direction of the shaft cylinder applied to the holder 20 '.
The shaft cylinder 10 ′ is composed of a single or a plurality of cylinders, like the shaft cylinder 10, and has an annular cam inclined surface 11a ′ that expands toward the front in a reduced-diameter opening on the front end side. Have.
The holder 20 ′ is engaged with the front opening of the shaft tube 10 ′ via the cam inclined surface 11a ′ so as to be able to advance and retreat, and is urged rearward by the holder urging member 13 in the shaft tube 10 ′. In the state where it has advanced against the urging force of the urging member 13, it can move in the axial cylinder radial direction.
That is, the holder 20 ′ has a configuration in which the cam inclined surface 20 a is replaced with the cam inclined surface 11 a ′ of the front opening portion of the shaft cylinder 10 ′ and the annular protrusion 20 a ′ is provided on the outer peripheral surface of the holder 20 ′. It has become. The annular protrusion 20a ′ is disposed so as to be in sliding contact with the cam slope 11a ′.
According to the writing instrument 2 shown in FIGS. 12 (a) and 12 (b), in the same manner as the above-described writing instrument 1, the lead core 31 of the writing core 30 protruding forward from the holder 20 ′ is crossed from the writing surface P in the cross direction. When a reaction force (writing pressure) is applied and the reaction force is larger than the normal writing pressure range, the holder 20 ′ receives the reaction force and causes the annular protrusion 20a ′ of the holder 20 ′ to Advancing while sliding to the cam slope 11a ′ of the front opening of 10 ′ and moving outward in the axial tube diameter.
Therefore, also with this writing instrument 2, the lead core 31 protruding from the holder 20 ′ can be covered and protected by the advancing holder 20 ′.
Further, the core powder generated by the advancement and retreat of the chuck 32b and the slide cylinder 32e is released in the axial direction by the core powder escape groove 32e2 (see FIG. 3) on the outer periphery of the slide cylinder 32e, and malfunction due to core powder adhesion can be reduced. .
Further, when the holder 20 ′ is retracted, the spring receiving portion 21 that retracts integrally with the holder 20 ′ comes into contact with the buffer material 33, and the buffer material 33 is elastically contracted. For this reason, it is possible to reduce the operation noise due to the retreat of the holder 20 ′ and the spring receiving portion 21.

  In addition, according to the said Example, when the holder 20 (or 20 ') tilts so that it may move forward while moving to a shaft cylinder diameter outward direction, the core tank 32a may be in contact with the shaft cylinder 10 on the rear end side. Although it was made to bend by contact (see FIG. 9), as another example, the core tank 32a may be swingably connected to the connection member 32m. In this other example, for example, a concave portion and a convex portion that fit in the axial direction of the shaft cylinder in a state having play may be provided on one and the other of the rear end side of the connecting member 32m and the front end side of the core tank 32a.

Moreover, according to the said Example, although the writing core 30 was made into the writing core for mechanical pencils (it may be called the refill for mechanical pencils), as another example, the writing core 30 is made into the writing core for ball-point pens ( Ball pen refill), a writing pen of a sign pen, a writing core of a marker pen, and a writing core of a correction pen.
For example, when a ball-point pen writing core having a needle-like (in other words, a long cylindrical shape) ball-point pen tip is used as the writing core 30, the needle-like portion of the ball-point pen tip is inserted into the holder 20, The front end portion projects forward from the front end of the holder 20 (or 20 ′), and the ballpoint pen writing core may be supported in a tiltable manner in the same manner as the writing core 30 in the shaft cylinder 10.

  In addition, when the writing core 30 is a writing core other than the writing core for mechanical pencils, the front end portion of the writing core protrudes from the front end of the holder 20 (or 20 ′) in a non-immersible manner, and the front end portion of the writing core is Both the aspect which protrudes from the front end of the holder 20 (or 20 ') are possible.

  Moreover, according to the said Example, although the cam slope was provided only in one of the front-end side opening part of a shaft cylinder and a holder, as another example, it is provided in both and a holder is provided by sliding contact between cam slopes. It is also possible to adopt a mode of moving forward.

Further, according to the above-described embodiment, the cam slope is provided on the outer peripheral surface of the holder 20 or the front opening of the shaft tube 10, but as another example, as shown in FIG. It is also possible to adopt a mode in which the rear end portion is provided.
The writing instrument 3 shown in FIG. 13 is provided with an annular recess loosely fitted to the front end edge of the shaft tube 10 ″ on the rear end side of the holder 20 ″, and the surface on the radially outer side in the recess is directed forward. The diameter of the cam slope 23 "is reduced. A pipe-shaped protective tube 22" is fixed to the front end of the holder 20 "so as to cover the lead core 31.
According to the writing instrument 3, as in the above-described embodiment, when a force in the crossing direction is applied to the holder 20 "via the lead core 31 at the front end of the writing core 30, the cam inclined surface 23" becomes the front end edge of the shaft cylinder 10 ". Then, the holder 20 ″ and the protective tube 22 ″ move forward (see the two-dot chain line in FIG. 13). That is, the cam inclined surface 23 ″ is moved by the outer force of the shaft cylinder diameter applied to the cam inclined surface 23 ″. It functions as a motion direction conversion mechanism for moving the "".
Therefore, the front end side of the lead core 31 can be covered and protected by the protective tube 22 "moving forward.
In addition, the core powder is released in the axial direction by the core powder escape groove 32e2 (see FIG. 3) by a mechanism substantially similar to the writing instruments 1 and 2 described above, and the malfunction due to core powder fixation can be reduced. The operation sound when the spring receiving portion 21 moves backward can be reduced by the cushioning material 33.

Moreover, according to the said Example, although the advance / retreat member 40 was interposed between the write-core support part 32g20 of the write-core 30, and the write-core urging | biasing member 50, like the writing instrument 4 shown in FIG. It can be omitted.
The writing instrument 4 shown in FIG. 14 is obtained by omitting the advance / retreat member 40 from the writing instrument 1 and replacing the writing core biasing member 50 with a writing core biasing member 50 ′.
The writing core urging member 50 'is a compression coil spring having a diameter that gradually decreases toward the front, and the front end of the writing core urging member 50' is received by the front end of the rear barrel 12 and the writing core support member 32g20. By making contact, the writing core 30 is urged directly forward.
Therefore, also with the writing instrument 4 shown in FIG. 14, when an excessive pressing force is applied to the lead core 31 backward, the writing core 30 is retracted against the biasing force of the writing core biasing member 50 ′. It is possible to prevent the lead core 31 from being broken.
Further, the core powder is released in the axial direction by the core powder escape groove 32e2 by a mechanism substantially the same as that of the writing instruments 1 and 2, and the malfunction due to the core powder fixing can be reduced, and the holder 20 and the spring receiving portion 21 can be reduced. The operating sound when the vehicle moves backward can be reduced by the cushioning material 33.

  The movement direction conversion mechanism (for example, the cam inclined surface 20a) has a structure other than the illustrated example as long as the holder is moved forward relative to the shaft cylinder and the writing core by the force in the outer diameter of the shaft cylinder applied to the holder. It is also possible.

  Further, according to the above embodiment, a plurality of core powder escape grooves 32e2 (six according to the illustrated example) on the outer periphery of the slide cylinder 32e are provided as a particularly preferable aspect. However, as another example, the core powder escape grooves 32e2 are provided. It is also possible to use a singular number or a number other than the illustrated example.

  Further, according to the above embodiment, the core powder escape groove 32e2 is provided on the sliding contact surface with the holding cylinder 32g on the rear side of the slide cylinder 32e as an aspect that effectively exhibits the action of releasing the lead core. As another example, on the front side of the slide cylinder 32e (specifically, on the front side of the diameter-enlarged portion 32e1 in FIG. 3), a groove that penetrates forward to the core powder escape groove 32e2 is provided. You may make it provide.

  Moreover, according to the said Example, although the slide cylinder 32e and the core powder escape groove | channel 32e2 were provided with respect to the mechanical pencil which made the holder 20, 20 'or 20 "advance and retreat, as another example, the said holder is used. Mechanical pencils that do not have (for example, inventions described in JP 2010-201813 A and 2010-094954) and refills for mechanical pens for multifunction writing instruments (for example, invention described in JP 2008-126596 A) For example, the slide cylinder 32e may be provided between the core breaker and the chuck.

  Further, the buffer material 33 in the above embodiment can be provided between the center shaft (2) and the pressing portion (3a) in the invention described in Japanese Utility Model Publication No. 63-180283, for example. Further, the cushioning material 33 is contracted by being pressed by the retreating holder in other writing instruments (including a ballpoint pen and a sign pen) in which the holder covering the writing core moves forward and backward relative to the shaft cylinder. It is possible to provide.

  Moreover, according to the said Example, although the spring receiving part 21 integral with the holder 20 was received by the buffer material 33, as another example, the holder 20 and the spring receiving part 21 are comprised as an integral member, A mode in which the integral member is received by the cushioning material 33 or the spring receiving portion 21 is omitted from the above configuration, and a protrusion for receiving the holder urging member 13 is formed on the outer periphery of the rear end side of the holder 20. It is also possible to adopt a mode or the like that is directly received by the buffer material 33.

1, 2, 3, 4: Writing instrument 10, 10 ', 10 ": Shaft cylinder 11c: Step part 11a: Front opening 13: Holder biasing member 20, 20', 20": Holder 20a, 11a ', 21 " : Cam slope 21: Spring receiving portion 30: Writing core 31: Lead core 32: Lead core feeding mechanism 32 a: Core tank 32 b: Chuck 32 c: Clutch ring 32 d: Core breaker 32 e: Slide cylinder 32 e 1: Expanded portion 32 e 2: Core powder Relief groove 32f: Slide cylinder biasing member 32g: Holding cylinder 32g1: Front side holding part 32g2: Rear side holding part 32g12: Front side contact part 32g20: Writing core support part 32g22: Contact part 32h: Core tank biasing member 33: Buffer material 40: Advance / retreat member 50: Writing core biasing member

Claims (5)

A chuck for advancing and releasing the sandwiched lead core; and a core breaker for holding the lead core inserted through the chuck at a position away from the chuck in a forward direction. In the lead lead feeding mechanism that feeds the lead lead forward of the lead breaker,
By providing a slide cylinder that advances and retreats in a state of covering the outer periphery of the lead core between the chuck and the core breaker, and an urging member that urges the slide cylinder backward relative to the core breaker, The chuck and the slide cylinder are moved forward and backward integrally,
A lead core feeding mechanism, wherein a core powder relief groove penetrating in the axial direction is provided on an outer peripheral surface of the slide cylinder.   2. The lead core feeding mechanism according to claim 1, wherein the inner peripheral surface of the slide cylinder is formed in a cylindrical shape which is continuous over the entire circumference and is close to or in contact with the outer peripheral surface of the lead core. .   The chuck includes a holding cylinder having the core breaker, the urging member, and the slide cylinder, and the slide cylinder slides an outer peripheral surface having the core powder escape groove to an inner peripheral surface of the holding cylinder. The lead core feeding mechanism according to claim 1 or 2, wherein the lead core feeding mechanism is advanced and retracted.   The said slide cylinder has an enlarged diameter part which diameter-expanded the rear part side rather than the front part side, and has formed the said core powder escape groove | channel in the outer peripheral surface of this enlarged diameter part. The lead core feeding mechanism according to any one of items 1 to 3.   A mechanical pencil comprising the lead lead feeding mechanism according to any one of claims 1 to 4.

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