JP2573054Y2 - Tactile stick-out mechanical pencil - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an operation in which, when a lead is worn out during writing, the finger is lightly pulled backward with a fingertip to a touch finger provided at the tip of the shaft while maintaining a writing state. In addition, the present invention relates to an improvement of a stylus dispensing mechanical pencil which enables dispensing of a required amount of lead.

[0002]

2. Description of the Related Art As a conventional example, the applicant of the present invention has disclosed a stylus extending mechanical pencil in Japanese Utility Model Publication No. 64-1107. According to this, a joining cylinder 6 is press-fitted and fixed to the outer periphery of the front end of the chuck case 2 to the shaft cylinder 7, and a shaft joint 8 is screwed to the inner diameter of the front end of the joining cylinder 6.
A screw portion is formed in the outer diameter portion of the front end of the shaft coupling 8,
A base 10 to which the tip pipe 9 is fixed is screwed here. A central portion 14 of a feeding body 13 fitted around the holding chuck 12 is provided inside the inner diameter of the shaft coupling 8, and the feeding body 13 projects a piece portion 15 outward from the center portion, and has a tip end at the tip thereof. The short finger portion 16 is formed. One part 15 of the feed-out body 13 penetrates a slit 17 provided in the axial direction from the tip of the shaft joint 8 toward the rear, and exposes the touch finger part 16 to the outer periphery of the shaft joint 8. In the case where the lead is normally fed out separately from the feed-out of the contact finger, the lead guide 1 connected to the knocking operation part compresses the coil spring 20 interposed between the joint cylinder 6 and the chuck case 2 to connect the shaft joint. 8 is advanced until it abuts against the rear end, and then the lead fixing chuck 4 is opened and the lead is fed out. When the knock is released, the chuck case 2 retreats, but at that time, it is necessary to retreat with the core fixing chuck 4 being opened. Therefore, lead guide 1
Needs to be configured to frictionally engage the outer periphery of the chuck case 2 with a stronger force than the coil spring 5. As described above, the conventional example has a disadvantage that it is easily deformed due to the provision of the slot 17 in the screw portion of the shaft coupling 8. For this reason, poor sliding of the feeding member 13 and loosening of the base 10 are likely to occur. Therefore, those members are actually provided by metal work products, and the member costs are relatively high. In addition, the conventional example has a problem that the cost is further increased since the number of parts is large and the number of screw portions is large.

[0003]

Therefore, the present invention improves the structural disadvantages of the conventional example, makes it possible to make most of the main members resinous, and eliminates the members so that the cost can be greatly reduced and the cost can be reduced. It is intended to provide a finger extension type mechanical pencil. Further, in the conventional example, there is a problem that the core is easily broken when a strong writing pressure is applied to the tip of the core. In addition, when repeatedly subjected to strong writing pressure, the lead fixing chuck is susceptible to deformation and abrasion because it is supported by point contact with the ball. If the pen pressure is too high, the core will go through)
There is a problem that occurs. In particular, the problem occurs remarkably when the core fixing chuck is made of resin. The purpose of the present invention is to solve that problem as well.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a stylus dispensing mechanical pencil of the present invention has a sufficient core holding force for writing due to a structure in which a core fixing chuck is tightened with a ball. However, it is a mechanical pencil that requires only a small amount of force to pull out the core from the chuck, and the barrel, base, feeding body, and touch finger are each formed as a synthetic resin molded product, and the center of the shaft side is slightly forward. A base provided with a guide slit is fixed to the end of the barrel by screwing or press-fitting, and a dispensing body having a locking piece which is slidably fitted into the guide slit is fitted inside the base. ,
A holding chuck is provided at the center of the feeding member, and a ring-shaped touch finger portion that engages with the locking piece and integrally works with the feeding member is exposed to the outside of the base. A coil spring is interposed between the base and the base to press the contact finger part forward, and a coil spring is arranged via a sliding tube behind a chuck case that tightens the core fixing chuck with a ball. When a strong writing pressure is applied to the tip of the lead, the chuck case is retracted together with the lead fixing chuck.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated embodiment will be described. An eraser stopper 27 having an eraser 28 attached thereto is fixed to a rear end hole of a lead case 9 which appropriately protrudes from the rear end of the barrel 1, and a rear end of the lead case 9 is provided. A knock cover 29 is detachably fitted on the outer periphery. In addition, a slit 23 composed of a slit 23a, a small slit filter 23b having a tapered portion 24, and a slit 23c having a step portion 25 is formed in the rear end side surface of the barrel 1 at the same position. Then, the protrusion 2 is provided on the side of the lead case 9 at the front end.
A rib-shaped bulging portion 26 having a protrusion 6a is provided.
6a is fitted into the slit 23a to elastically deform the tapered portion 24, the rear end of the projection 26a abuts the step 25 of the slit 23c, and the core case 9 is prevented from coming off behind the shaft cylinder 1. A clip 30 is integrally provided on a side surface of the knock cover 29, a groove 31 is provided on one side of a hole to be fitted into the lead case 9, and a rib-shaped bulging portion 26 is fitted into the knocked cover 29. The cover 29, the core case 9, and the barrel 1 are integrated in the rotation direction.

A lead guide 10 is formed integrally with the leading end of the lead case 9, and a protrusion 11 is provided on the outer periphery of the lead guide 10. Further, a slit portion 7 is formed on a rear end side surface of the chuck case 2 described later, and a locking portion 8 is provided on the side surface portion. The core guide 10 is the chuck case 2
The projection 11 engages with the locking portion 8 in the rear end hole.
The core case 9 is normally urged rearward by the coil spring 12 between the flange portion 9b and a rear end portion 22c of a slide tube 22 described later. The rear end of the flange 9b is the shaft cylinder 1.
Abuts on the step portion 1a provided at (The flange 9b is locked to the step 1a using elastic deformation.) When the step 1a is provided, there is no need to provide a configuration in which the protrusion 26a abuts on the step 25. (Choose one for your convenience)

[0007] A fastening cylinder 6 is fixed to the tip of the chuck case 2. The inner diameter portion at the front end of the tightening cylinder 6 has a tapered shape, and a core fixing chuck 3 in which balls 4, 4 す る in contact with the tapered surface are fitted into the outer surface recess is provided. It is pressed rearward by a coil spring 5 interposed between a step formed at the rear end. The core fixing chuck 3 is made of a synthetic resin molded article having excellent elasticity and high abrasion resistance, and is configured in a state where a split cylindrical body is combined. When writing pressure acts on the lead, the balls 4 and 4 roll and the lead fixing chuck 3 is tightened by the wedge effect to hold the lead, but when the lead is pulled out forward, the spring force of the coil spring 5 is used. Is set to be weak so that it becomes possible with a small force of about several grams. Incidentally, the chuck case 2 is formed of a resin molded product, and the tightening cylinder 6 is formed of metal processing. Originally, the chuck case and the tightening cylinder are integrally formed, but the cost is high if the metal is used due to the complicated processing. In addition, durability is insufficient when made of resin. The reason why the tightening cylinder 6 is made of metal is that consideration is given to wear resistance due to rolling of the ball and rigidity of the tapered portion. As will be described later, according to the configuration of the present invention, the chuck case 2 and the tightening cylinder 6 can be formed as an integral resin molded product.

A screw portion is formed in the inner diameter portion of the front end of the barrel 1, and a resin base 13 to which a tip pipe 14 is fixed is screwed to the screw portion. The base 13 may be press-fitted into the front end inner diameter of the barrel 1 in some cases. Further, the tip pipe may be formed integrally with the base 13. Further, a guide slit 15 is formed in the center of the side surface of the base 13 slightly in front of the shaft, and a feeding body 16 is slidably fitted inside the base 13. The feeding body 16 is centered on the holding chuck 1.
8 is fixedly provided, and a locking piece 19 having a locking groove 19a is integrally formed at a predetermined position corresponding to the guide slit 15 on the outer periphery on the rear end side. And is slidable. Also, a gap is provided between the tip of the tightening cylinder 6 and the opposing surface when the feeding body 16 is at the forefront position of the base 13 by the amount of feeding by the knocking operation.

The touch finger portion 20 is made of a resin having a ring shape, and a projection 20a is formed at a position corresponding to the locking groove 19a at an inner peripheral portion at a substantially distal end. The contact part 20 is the base 1
3 and the projection 20a is elastically
a, the touching finger portion 20 and the extending member 16 are integrally linked. Also, the rear end of the touch finger portion 20 and the base 1
3 is provided with an interval for feeding out a touch finger.

Further, a coil spring 21 is interposed between the finger part 20 and the base 13 inside the finger part 20 to urge the finger part 20 forward. Since the spring force of this spring is larger than the force for pulling out the lead from the lead fixing chuck 3, it can be set to about 10 to 20 grams.

A groove 2a and a flange 2b are provided substantially at the outer periphery of the center of the chuck case 2, and a cylinder having a slit 7 is provided behind the groove 2a and the flange 2b. On the other hand, the sliding tube 22
A ring-shaped protrusion 22a is formed at an outer diameter portion and a ring-shaped protrusion 22b is formed at an inner diameter portion at a front end of the slide case 22. The slide tube 22 is fitted to a rear portion of the chuck case 2 so that the protrusion 22b is formed into a groove 2a. Are fitted to each other by mutual elastic deformation. The front end of the slide tube 22 is in contact with the rear end surface of the base 13 and the chuck case 2
In contact with the front end of the groove 2a. That is, the chuck case 2 is prevented from retreating against the urging force of the coil spring 12.

[0012]

The dispensing body 16 can be slid rearward by pulling it lightly rearward with the external touch finger portion 20 and moving the locking piece 19 along the guide slit 15.
Next, when the finger is released, the holding chuck 18 holds the lead and returns forward, so that the lead can be extended. The extension amount is a value of an interval at which the rear end of the touch finger portion 20 comes into contact with the step portion of the base 13 facing the same. When the lead is normally extended, the rear end of the knock cover 29 may be knocked. The lead guide 10 at the front end of the lead case 9 connected to the knock cover 29 is provided with the flange 9b and the rear end 22c of the slide tube 22. The compression cylinder 6 integrated with the chuck case 2 is advanced while compressing the coil spring 12 interposed between the protrusions 1 and 2 (as shown in FIG.
1 contacts the projection 8b constituting the locking portion 8, so that the core guide 10 and the chuck case 2 are interlocked.) The front end thereof abuts against the step 16a of the feeding member 16 facing the same. When the wick protrudes from the tip pipe 14, the wick advances at an interval at which the tip of the tightening cylinder 6 abuts the step 16 a of the feeding body 16. In this state, the forward movement of the chuck case 2 is prevented, so that the protrusion 11 elastically moves over the protrusion 8b and moves forward. 3 is released. (In a state where the lead does not pass through the lead fixing chuck 3, the lead falls at this time and abuts on the holding chuck 18 or abuts on the rear end of the previous lead.) Then, the rear end knock of the knock cover 29 is released. Since the rear end of the projection 11 comes into contact with the projection 8b, the chuck case 2 retreats together with the core case 9 while the fixed chuck 3 is opened with the core fixed to the holding chuck 18, and the chuck case 2 is moved. When the sliding tube 22 is prevented from retreating at the front end, only the lead case 9, ie, the lead guide 10, is retracted, and the protrusion 11 climbs over the protrusion 8b again and is located between the protrusion 8a. By repeating the above, the core is sequentially drawn out. (Even when the lead is in contact with the holding chuck 18 or the rear end of the preceding lead, the lead advances by repeating the knocking operation.)

When a strong writing pressure is applied while the lead projects from the tip pipe 14, the chuck case 2 retreats together with the lead fixing chuck 3, so that the lead retreats to prevent the lead from breaking. Further, when the rear end of the core fixing chuck 3 abuts on the front end of the core guide 10, the core fixing chuck 3 slightly advances to release the gripping of the core, so that the core fixing chuck 3 is not forced. When the lead is retracted by a strong writing pressure, when the writing pressure is released, the lead protrudes from the distal end pipe 14 to the original state, but the rear end of the lead fixing chuck 3 contacts the front end of the lead guide 10. Then, the return amount of the core corresponding to the contact interval is obtained. Therefore, when the core projects long and the core retreats to the same plane as the distal end pipe 14, the protrusion amount is adjusted to the same value as the contact interval. That is, if the contact interval is appropriately set, the length of the core projecting from the distal end pipe 14 can be adjusted to an appropriate size. It is desirable that the load at which the chuck case 2 retreats is set to about 400 to 700 g from the viewpoint of writing work. In other words, when the pen pressure is further applied, the core protruding from the tip pipe 14 retreats (submerges in the core pipe).

[0014]

[Effects of the Invention] The present invention is as described above. Since there is no notched slit to the end of the conventional shaft coupling, structural defects such as poor sliding of the touch finger portion and loosening of the screw portion are eliminated. You.
Further, the shaft cylinder, the base, the feed-out body, and the touch finger portion are each formed as a synthetic resin molded product, and the members are simplified, so that a significant cost reduction can be achieved. In addition, although there is a problem of quality due to processing variations in conventional complicated metal processing and screwed portions, in the present application, since it can be formed by resin molding using a metal mold, there is no variation between members and the effect of stabilizing quality is also exhibited.
In addition, when strong writing pressure is applied, the core retracts into the tip pipe, preventing the core from breaking.Also, no excessive load is applied to the core fixing chuck, so deformation and wear related to the core gripping function are reduced. As a result, the life can be significantly extended. Also, if the core protrudes long from the tip pipe,
When the lead is retracted to the same plane as the front end pipe with strong writing pressure, releasing the writing pressure makes it possible to adjust the amount of projection of the lead to an appropriate value.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a stylus protruding mechanical pencil according to an embodiment of the present invention, with a part thereof being half-sectioned;

FIG. 2 is an overall vertical sectional view of a stylus extending mechanical pencil according to an embodiment of the present invention;

FIG. 3 is a front view showing an external appearance of a stylus extension type mechanical pencil which is an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part showing an engagement portion between the lead guide and the chuck case of the present invention.

FIG. 5 is a view showing a fastening portion between the lead case and the shaft cylinder according to the present invention;

[Explanation of symbols]

 Reference Signs List 1 shaft cylinder 1a stepped portion 2 chuck case 2a groove portion 2b flange portion 3 core fixing chuck 3a gap 4 ball 4 ｀ ball 5 coil spring 6 tightening cylinder 7 slit portion 8 locking portion 8a projection 8b projection 9 core case 10 core guide DESCRIPTION OF SYMBOLS 11 Projection part 12 Coil spring 13 Cap 14 Tip pipe 15 Guide slit 16 Feeding body 16a Step 17 Central part of feeding body 18 Holding chuck 19 Locking piece 19a Locking groove 20 Touch finger part 20a Projection 21 Coil spring 22 Sliding Pipe 22a Projection 22b Projection 22c Rear end 23 Slit 23a Slit 23b Small slit filter 23c Slit 24 Tapered 25 Step 26 Rib-shaped bulge 26a Projection 27 Eraser stopper 28 Eraser 29 Knock cover 30 Clip 31 grooves

Claims (1)

(57) [Scope of request for utility model registration] 1. A structure in which a core fixing chuck 3 is tightened with a ball to have a sufficient core holding force for writing, but a sharp force that requires only a small force to pull the core out of the core fixing chuck 3. In the pencil, the main members of the barrel 1, the base 13, the feeding body 16, and the touch finger portion 20 are each formed as a synthetic resin molded product, and the base 13 in which the guide slit 15 is formed slightly in front of the center of the side surface of the shaft. A feeding body 16 having a locking piece 19 which is fixed to the tip of the barrel 1 by screwing or press fitting or the like and which is slidably fitted into the guide slit 15 by being fitted into the base 13 is fitted. 1
6, a holding chuck 18 is provided at the center of the
A ring-shaped touch finger portion 20 which is engaged with the feeding member 16 and is integrally formed with the extension member 16 is provided to be exposed to the outside of the base 13, and inside the touch finger portion 20, the contact between the touch finger portion 20 and the base 13 is provided. The contact portion 20 is pressed forward with a coil spring 21 interposed therebetween, and the coil spring 12 is disposed via a sliding tube 22 behind the chuck case 2 in which the core fixing chuck 3 is tightened with a ball. A stylus extension type pencil, wherein the chuck case 2 is retracted together with the core fixing chuck 3 when a strong writing pressure is applied to the tip of the core.