JPH07237391A - Finger touching letting-out type propelling pencil - Google Patents

Abstract

PURPOSE:To remarkably reduce production cost by a method wherein conventional structural and operational faults are improved and, at the same time, major members are resinified so as to simplify them. CONSTITUTION:A mouth piece 13, on the axial side surface of which a guide slit 17 is bored, is threadingly, pressingly fixed to the tip of a shaft tube 1. A letting-out body 14, having an engaging piece 18 is installed within the mouth piece by being inserted in the guide slit so as to provide a holding chuck 16 at at the center of the letting-out body 14 and to fix a tip pipe 15 at the top of the letting-out body under the condition that the tip pipe 15 piercingly pushed out through the tip of the mouth piece 13. An annular finger touching part 19, which interlocks integrally with the letting-out body 14 through the engagement with the engaging piece 18, is exposed to the exterior of the mouth piece 13 under the condition that the finger touching part 19 is pressed forwards by interposing a coiled spring 20 between the finger touching part 19 and the mouth piece 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when the lead is worn out during writing, has a touching portion provided at the tip of the shaft with the fingertip lightly pulling backward with the fingertip and releasing it. The present invention relates to an improvement of a touch-finger-feeding type mechanical pencil that allows the required amount of lead to be fed.

[0002]

2. Description of the Related Art As a conventional example, the applicant of the present application discloses a touch-fing type mechanical pencil in Japanese Utility Model Publication No. 64-1107. According to this, the joining cylinder 6 is press-fitted and fixed to the shaft cylinder 7 on the outer periphery of the front end portion of the chuck case 2, and the shaft joint 8 is screwed to the inner diameter portion of the front end of the joining cylinder 6.
A screw portion is formed on 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 a holding chuck 12 is provided inside the shaft coupling 8, and the feeding body 13 projects a piece 15 outward from the central portion and has a tip end thereof. A short tubular touch finger 16 is configured. The piece portion 15 of the payout body 13 penetrates a slit 17 provided in the axial direction from the tip of the shaft coupling 8 toward the rear, and exposes the touching finger portion 16 to the outer peripheral portion of the shaft coupling 8. In the case where the lead is normally fed out separately from the finger-feeding, the lead case 1 connecting to the knock operation portion compresses the coil spring 20 interposed between the lead pipe 1 and the joining cylinder 6, and the chuck case 2 is attached to the shaft joint. The lead fixing chuck 4 is advanced until it abuts against the rear end of the lead 8, and then the lead fixing chuck 4 is opened to feed the lead. When the knock is released, the chuck case 2 retreats, but at that time, it is necessary to retreat with the lead fixing chuck 4 left open. Therefore, core guide 1
Must be configured to frictionally engage the outer circumference of the chuck case 2 with a stronger force than the coil spring 5. As described above, the conventional example has a drawback that the threaded portion of the shaft joint 8 is provided with the slit 17 and is easily deformed. Therefore, sliding failure of the payout body 13 and loosening of the mouthpiece 10 are likely to occur. Therefore, in reality, these members are provided as metal products, and the cost of the members is relatively high. In addition, the conventional example has a large number of parts and a large number of screwed portions, and thus there is a problem of further cost increase. Further, in the above-mentioned conventional example, since the tip pipe is fixed to the tip of the die, there is a problem that the writing surface is broken when the writing is performed with the tip of the lead being flush with the tip of the tip pipe during writing. It may be enough to perform the operation of extending the finger to prevent such a problem, but it may be forgotten. In the case of a mechanical pencil for drawing having a long tip pipe, it is advantageous that the tip pipe is firmly fixed, but it is often a drawback in general writing.

[0003]

SUMMARY OF THE INVENTION Therefore, the present invention improves the structural and operational defects of the conventional example, allows most of the main members to be made of resin, and eliminates the members, resulting in a significant cost reduction. It intends to provide an inexpensive touch-up 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 a strong writing pressure is repeatedly applied, the core fixing chuck is supported by the point contact of the ball, so it is easily affected by deformation and wear, which reduces the gripping force of the core and reduces the core slippage ( There is a problem that the core will come off when strong writing pressure is applied. Especially, when the core fixing chuck is made of resin, it remarkably occurs. The present invention aims to solve that problem as well.

[0004]

In order to achieve the above object, the finger-feeding type mechanical pencil of the present invention has a sufficient core holding force for writing due to a structure in which a lead 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 lead from the chuck, and the shaft cylinder, the mouthpiece, the feeding body, and the touch finger are each formed as a synthetic resin molded product, and the shaft side surface is slightly forward of the center. The base with a guide slit is fixed to the tip of the barrel by screwing or press fitting, and the feeding body fitted with the guide slit and having a slidable locking piece is fitted inside the base. ,
A holding chuck is provided at the center of the feeding body, and a tip pipe is fixed to the tip side so that the tip pipe extends from the tip of the mouthpiece, and a ring-shaped contact is made with the locking groove provided on the outer periphery of the locking piece. A touching finger portion, which is elastically engaged with a protrusion formed on the inner surface of the finger portion and is interlocked with the feeding body, is provided outside the mouthpiece, and the touching finger portion and the mouthpiece are provided inside the touching finger portion. It is characterized in that a coil spring is interposed between the contact fingers and the touch finger portion is pressed forward.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Explaining the illustrated embodiment, an eraser stopper 26 having an eraser 27 attached to a rear end hole of a core case 9 that appropriately protrudes from the rear end of the barrel 1 is attached to the rear end of the core case 9. A knock cover 28 is detachably fitted on the outer periphery. Further, a slit 22a having a slit 22a, a small slit 22b having a taper portion 23, and a slit 24c having a step portion 24 is formed on the rear end side surface of the shaft cylinder 1. At the position, a rib-shaped bulging portion 25 having a protrusion 25a at the front end is provided on the side surface of the core case 9, and the protrusion 25a is fitted into the slit 22a to elastically deform the taper portion 23 and thereby the protrusion 25a. The rear end of the slit is in contact with the stepped portion 24 of 22c so that the core case 9 is prevented from coming out behind the barrel 1. Further, a clip 29 is integrally provided on a side surface of the knock cover 28, a groove 30 is provided on one side of a hole portion to be fitted into the core case 9, and a rib-shaped bulging portion 25 is fitted therein. The cover 28, the core case 9 and the barrel 1 are integrated in the rotational direction.

A lead guide 10 is integrally formed at the tip 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 the rear end side surface of the chuck case 2, which will be described later, and a locking portion 8 is provided on the side surface portion. The core guide 10 is the chuck case 2
The protrusion 11 and the locking portion 8 engage with each other by fitting into the rear end hole.
Further, the core case 9 is normally urged rearward by the coil spring 12 between the flange portion 9b and a rear end portion 21c of a sliding tube 21 described later. Further, the rear end of the collar portion 9b has the barrel 1
It is in contact with the step portion 1a provided on the. (The collar portion 9b is locked to the step portion 1a by utilizing elastic deformation.) When the step portion 1a is provided, it is not necessary to bring the projection 25a into contact with the step portion 24. (Choose one for your design)

A tightening cylinder 6 is fixed to the tip of the chuck case 2. The inner diameter of the front end of the tightening cylinder 6 has a tapered shape, and the core fixing chuck 3 having the balls 4 and 4'which are in contact with the tapered surface in the outer surface recess is fitted therein. The coil spring 5 interposed between the stepped portion formed at the rear end pushes the coil spring 5 rearward. The core fixing chuck 3 is made of a synthetic resin molded product having excellent elasticity and high abrasion resistance, and is constructed by combining two split cylindrical bodies. When the writing pressure acts on the core, the balls 4 and 4'roll and the core fixing chuck 3 is tightened by the wedge effect to hold the core. However, when the core is pulled out forward, the spring force of the coil spring 5 is increased. Is set to be weak so that a small force of about several grams is possible.

By the way, the chuck case 2 is formed of a resin molded product, and the tightening cylinder 6 is formed of metal. Originally, the chuck case and the closing cylinder are integrally formed, but the cost is high if they are made of metal because of complicated processing. or,
If it is made of resin, the durability will be insufficient. The reason why the tightening cylinder 6 is made of metal is that the wear resistance due to rolling of the balls and the rigidity of the tapered portion are taken into consideration. As will be described later, according to the configuration of this embodiment, the chuck case 2 and the tightening cylinder 6 can be integrated into a resin molded product.

Further, a screw portion is formed on the inner diameter portion of the front end of the shaft cylinder 1, and a cap 13 made of resin is screwed onto the screw portion.
The base 13 may be press-fitted into the inner diameter portion of the front end of the barrel 1. A guide slit 17 is formed in the center of the shaft side surface of the mouthpiece 13 slightly forward, and a payout body 14 is slidably fitted inside the mouthpiece 13.

The feeding member 14 has a holding chuck 16 at the center.
Is fixed, and a locking piece 18 having a locking groove 18a is integrally formed at a predetermined position corresponding to the guide slit 17 on the outer periphery of the rear end side, and the locking piece 18 is fitted into the guide slit 17 and slides. It is made movable. Further, there is provided a gap corresponding to the amount of extension by knocking operation between the tip of the fastening cylinder 6 and the facing surface when the delivery member 14 is at the frontmost position of the mouthpiece 13. Further, a tip pipe 15 is fixed to the front of the holding chuck 16 of the feeding body 14, and the tip of the tip pipe 15 is provided so as to project from the tip of the mouthpiece 13 as appropriate. The tip pipe 15 moves back and forth at the tip of the base 13.

The touch finger portion 19 is made of a resin having a ring shape, and the engaging groove 1 of the feeding body 14 is provided at the inner peripheral portion of the tip end thereof.
A protrusion 19a is formed at a location corresponding to 8a. The touching finger portion 19 is fitted to the outside of the mouthpiece 13, the protruding portion 19a is elastically fitted into the locking groove 18a and engaged with each other, and the touching finger portion 19 and the feeding body 14 are integrally interlocked. In addition, the touch finger 1
A space is provided between the rear end of the base 9 and the mouthpiece 13 for extending the fingers.

Inside the touch finger portion 19, a coil spring 20 is interposed between the touch finger portion 19 and the base 13 to urge the touch finger portion 19 forward in a pressed state. The spring force of the spring 20 may be larger than the force for pulling out the lead from the lead fixing chuck 3, and can be set to about 10 to 20 grams.

By the way, a groove portion 2a and a flange portion 2b are provided on the outer periphery of the center of the chuck case 2, and a cylindrical portion having a slit portion 7 is provided behind the groove portion 2a and the flange portion 2b. On the other hand, at the front end of the sliding tube 21, a ring-shaped projection 21a is formed on the outer diameter side and a ring-shaped projection 21b is formed on the inner diameter side, and the sliding tube 21 is fitted on the rear part of the chuck case 2. The protrusion 21b is fitted into the groove 2a by elastic deformation between them. Further, the front end of the sliding tube 21 is in contact with the rear end surface of the mouthpiece 13 and is in contact with the front end of the groove portion 2 a of the chuck case 2. That is, the chuck case 2 is prevented from retreating against the biasing force of the coil spring 12.

[0014]

In the state where the core is inserted to the tip of the tip pipe 15, the feeding body 14 is pulled rearward lightly with the finger of the external touching finger portion 19 and the locking piece 18 is guided along the guide slit 17. Can be slid backwards.
Next, when the finger is released, the holding chuck 16 holds the lead and returns to the front, so that the lead can be fed. The lead-out amount of the lead is a value of an approximately interval at which the rear end of the touching finger portion 19 abuts on the facing step portion of the mouthpiece 13.

When the tip of the tip pipe 15 is pressed against the paper surface for writing, the tip pipe 15 and the feeding body 14 are retracted as the core is consumed, and writing can be performed.
Therefore, even if the user forgets to operate the touch finger section 19 (that is, the operation of the feeding body 14), the user can write without the problem of breaking the paper surface. still,
When the tip pipe 15 rubs against the paper surface and the user feels that the writing feel is poor, the touch finger portion 19 may be operated.

When the lead is normally fed out, the rear end of the knock cover 28 may be knocked, and the lead guide 10 at the tip of the lead case 9 connected to the knock cover 28 is provided with the flange 9b and the rear end of the sliding tube 21. While compressing the coil spring 12 interposed between the portion 21c and the chuck case 2, the tightening cylinder 6 integrated with the chuck case 2 is moved forward (the projection 11 forms the locking portion 8 as shown in FIG. 4). The core guide 10 and the chuck case 2 are interlocked with each other when they come into contact with the portion 8b. The tip is a pipe 1
In the case where it projects from 5, the lead moves forward at an interval where the tip of the tightening cylinder 6 collides with the stepped portion 14a of the feeding body 14.

In this state, the chuck case 2 is prevented from moving forward, so that the protrusion 11 elastically rides over the protrusion 8b and moves forward, and the tip of the lead guide 10 comes into contact with the rear end of the lead fixing chuck 3. The lead fixing chuck 3 is released. (When the lead is not inserted through the lead fixing chuck 3, the lead falls at this time and comes into contact with the holding chuck 16 or the rear end of the previous lead.)

Next, when the rear end knock of the knock cover 28 is released, the rear end of the protrusion 11 abuts on the protrusion 8b, so that the fixed chuck 3 remains open and the fixed chuck 3 remains open. Chuck case 2 with case 9
When the chuck case 2 is retracted at the front end of the sliding tube 21 and only the core case 9, that is, the core guide 10, is retracted and the projection 11 passes over the projection 8b again and the projection 8 is retracted.
It is located between a and. By repeating the above, the lead is sequentially fed out. (Even when the lead is in contact with the holding chuck 16 or the rear end of the front lead, the lead advances by repeating the knocking operation)

Further, when strong writing pressure is applied with the lead protruding from the tip pipe 15, the chuck case 2 retracts together with the lead fixing chuck 3, so that the tip pipe 15 and the lead retract first and the tip ends. At the retracted limit of the pipe 15 (retracted limit of the touching finger portion), only the lead retracts and core breakage is prevented. or,
When the projecting lead is long, when the rear end of the lead fixing chuck 3 comes into contact with the front end of the lead guide 10, the lead fixing chuck 3 slightly advances and the holding of the lead is released. I don't care.

A strong writing pressure is applied to the core and the core and the tip pipe 1
When 5 is retracted, the lead and the tip pipe 15 project to the original state when the writing pressure is released, but when the lead is long, the rear end of the lead fixing chuck 3 is in contact with the front end of the lead guide 10. At this point, only the core retracts, and the length corresponding to the abutting distance becomes the protrusion amount of the core. That is, if the abutting interval is set to an appropriate size, it is possible to have an action of adjusting the length of the core protruding from the tip pipe 15 to an appropriate size. still,
The load with which the chuck case 2 retracts is preferably set to about 400 to 700 g in consideration of the appropriateness of the writing work. That is, when a writing pressure higher than that is applied, the lead and the tip pipe 15 are retracted.

[0021]

As described above, the present invention eliminates structural defects such as poor sliding of touching finger portions and loosening of screwed portions because there is no notched slit up to the tip of a conventional shaft coupling. It
Further, the shaft cylinder, the base, the feeding body, and the touching finger portion are each formed as a synthetic resin molded product, and the simplification of the members is achieved, so that the cost can be greatly reduced. Further, although there is a problem of quality in the conventional complicated metal working and screwing part due to processing variations, since the present invention can be formed by resin molding using a mold, there is no variation between members and the quality is stabilized.
Further, since the user can write even if he / she forgets to operate the touching portion, it is possible to prevent the problem of breaking the paper surface by writing. Also, when a strong writing pressure is applied, the lead and the tip pipe retract first, and then only the lead retracts into the tip pipe, preventing core breakage and avoiding an unreasonable load on the lead fixing chuck. Therefore, the deformation and wear associated with the gripping function of the core are reduced, and the life can be remarkably extended. In addition, when the lead protrudes from the tip pipe for a long time, it is possible to adjust the protrusion amount of the lead appropriately by releasing the writing pressure after the lead retracts to the same surface as the tip pipe with strong writing pressure. The effect is great.

[Brief description of drawings]

FIG. 1 is an enlarged vertical cross-sectional view of a main part of a finger-feeding type mechanical pencil according to an embodiment of the present invention, a part of which is half-sectioned.

FIG. 2 is a vertical cross-sectional view of an entire touch-finger type mechanical pencil, which is an example, in which a part thereof is half-sectioned.

FIG. 3 is a front view showing the outer appearance of the touch-fing type mechanical pencil according to the embodiment.

FIG. 4 is a cross-sectional view of an essential part showing an engaging portion between a lead guide and a chuck case of the embodiment, which is partially non-cross-sectional.

FIG. 5 is a diagram showing a fastening portion between the core case and the shaft cylinder of the embodiment.

[Explanation of symbols]

 1 Shaft 1a Step 2 Chuck case 2a Groove 2b Collar 3 Core fixing chuck 3a Gap 4 Ball 4'ball 5 Coil spring 6 Tightening cylinder 7 Slit 8 Locking 8a Projection 8b Projection 9 Core case 10 Core guide 11 Projection 12 Coil Spring 13 Mouthpiece 14 Feeder 14a Step 14b Center of Feeder 15 Tip Pipe 16 Holding Chuck 17 Guide Slit 18 Locking Piece 18a Locking Groove 19 Touch Finger 19a Projection 20 Coil Spring 21 Sliding Pipe 21a Projection 21b Projection 21c Rear end 22 Slit 22a Slit 22b Small slit 22c Slit 23 Tapered 24 Step 25 Rib-shaped protrusion 25a Protrusion 26 Eraser stopper 27 Eraser 28 Knock cover 29 Clip 30 grooves

Claims (2)

[Claims] 1. A structure in which the core fixing chuck 3 has a ball-tightening structure to have a sufficient core holding force for writing, but a slight force is required to pull out the core from the core fixing chuck 3. In the pencil, the main member of the shaft cylinder 1, the mouthpiece 13, the feeding body 14, and the touch finger portion 19 are formed as synthetic resin molded products, respectively, and the mouthpiece 13 is formed with a guide slit 17 slightly in the center of the side surface of the shaft. Fixed to the tip of the shaft cylinder 1 by screwing, press fitting, or the like, and fitted in the inside of the mouthpiece 13 is a feeding body 14 fitted in a guide slit 17 and having a slidable locking piece 18. 1
4 is provided with a holding chuck 16 at the center and a tip pipe is fixed to the tip so that the tip pipe penetrates from the tip of the mouthpiece 13 and is provided in an engaging groove 18a provided on the outer periphery of the engaging piece 18. A protrusion 19a formed on the inner surface of the ring-shaped touching finger portion 19 is elastically engaged with the touching finger portion 19 that is integrally interlocked with the feeding body 14 and is provided outside the mouthpiece 13. A finger-feeding type mechanical pencil, characterized in that a coil spring 20 is interposed between the touch finger portion 19 and the mouthpiece 13 inside the touch finger portion 19, and the touch finger portion 19 is pressed forward. 2. A coil spring 12 is disposed behind a chuck case 2 for tightening the lead-fixing chuck 3 with a ball through a sliding tube 21, and the lead-fixing chuck 3 is provided when a strong writing pressure is applied to the tip of the lead. 2. The touch-fing type mechanical pencil according to claim 1, wherein the chuck case 2 is also retracted.