JPH0636890U - Tentacle extension type mechanical pencil - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The cost can be reduced significantly by simplifying the members, core breakage is prevented, and the life of the core gripping function is extended. [Structure] Base 1 having guide slits 15 on the shaft side surface
3 is fixed to the tip of the shaft cylinder 1, and a payout body 16 having a locking piece 19 slidably fitted in the guide slit 15 is provided inside the mouthpiece 13. A holding chuck 18 is provided at the center of the payout body 16, and a ring-shaped touch finger portion 2 that engages with a locking piece 19 on the outside of the mouthpiece 13 to integrally interlock with the payout body 16.
0 is set. Inside the touching part 20, the touching part 20 and the base 1
3 with a coil spring 21 interposed between
0 is pressed forward, and further, the sliding tube 22 is provided behind the chuck case 2 in which the lead fixing chuck 3 is tightened with a ball.
The coil spring 12 is arranged via the so that the chuck case 2 can be retracted when a strong writing pressure is applied to the tip of the core.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 With the present invention, when the core is worn out during writing, the necessary amount can be obtained by adding the operation of gently pulling back with the fingertip to the touch finger provided on the tip of the shaft while maintaining the writing state and releasing it. The present invention relates to the improvement of a mechanical pencil that can be used to extend the lead of a finger.

[0002]

[Prior art]

 As a conventional example, the present applicant has disclosed a finger-feeding type sharp 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, and a cap 10 having a tip pipe 9 fixed thereto is screwed onto the screw portion. 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 portion at its tip. A short tubular touch finger 16 is configured. The piece portion 15 of the feeding body 13 penetrates a slit 17 provided in the axial direction from the front end of the shaft coupling 8 toward the rear, and exposes the touching portion 16 on the outer peripheral portion of the shaft coupling 8. . When the lead is normally fed apart from the touching-out, the lead case 1 connected to the knock operation part compresses the coil spring 20 interposed between the lead tube 1 and the joining cylinder 6, and the chuck case 2 is connected to the shaft joint. 8 is advanced until it abuts against the rear end of the lead 8, 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 while the lead fixing chuck 4 remains open. Therefore, the lead guide 1 needs to be configured to frictionally engage the outer circumference of the chuck case 2 with a force stronger than that of the coil spring 5. As described above, the conventional example has a drawback that the threaded portion of the shaft coupling 8 is easily deformed by providing the slit 17 therein. Therefore, the sliding failure of the payout body 13 and the loosening of the mouthpiece 10 are likely to occur. Therefore, in reality, these parts are made of metal processed products and the cost of parts is relatively high. Further, 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.

[0003]

[Problems to be solved by the device]

 Therefore, the present invention does not provide an inexpensive touch-finger-type mechanical pencil that improves the structural defects of the conventional example, allows most of the main members to be made of resin, and omits the members, resulting in a significant cost reduction. It is what 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 received, the core fixing chuck is liable to be affected by deformation and wear because it is supported by the point contact by the ball, which reduces the grip force of the core and causes the core to slip. 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]

[Means for Solving the Problems]

 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 the structure in which the core-fixing chuck is tightened with a ball, but the core is pulled out from the chuck. It is a sharp pencil that requires only a small amount of force, and the barrel, the die, the feeding body, and the touch finger are each formed as a synthetic resin molded product, and a die with a guide slit drilled slightly in the center of the side of the shaft. Fix the shaft to the tip of the barrel by screwing or press-fitting, and insert the feeding body with the locking piece that fits in the guide slit and is slidable inside the die, and hold the chuck at the center of the feeding body. The ring-shaped touching finger portion that engages with the locking piece and works together with the feeding body is exposed to the outside of the mouthpiece, and is provided inside the touching finger portion between the touching finger portion and the mouthpiece. Intervening coil spring When the touching finger is pressed forward, and the core fixing chuck is tightened with a ball, a coil spring is placed behind the chuck case via a sliding tube, and when a strong writing pressure is applied to the tip of the core. It is characterized in that the chuck case retracts together with the lead fixing chuck.

[0005]

Embodiments To explain the illustrated embodiment, an eraser stopper 27 having an eraser 28 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 29 is detachably fitted on the outer periphery. Further, a slit 23a having a slit 23a, a small slit 23b having a taper portion 24, and a step portion 25 having a step 23 is provided on the rear end side surface of the shaft cylinder 1, At the same position, a rib-shaped bulging portion 26 having a protrusion 26a at the front end is provided on the side surface of the core case 9, and the protrusion 26a is fitted into the slit 23a to elastically deform the taper portion 24 and thereby the protrusion 26a. The rear end of the slit abuts against the stepped portion 25 of 23c so that the lead case 9 is retained behind the barrel 1. Further, a clip 30 is integrally provided on the side surface of the knock cover 29, a groove 31 is provided on one side of a hole to be fitted into the core case 9, and a rib-shaped bulging portion 26 is fitted therein, so that a knock is generated. The cover 29, 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 circumference 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 fitted into the rear end hole of the chuck case 2 so that the protrusion 11 and the locking portion 8 are engaged with each other. The core case 9 is normally urged rearward by a coil spring 12 between a flange portion 9b of the core case 9 and a rear end portion 22c of a sliding tube 22 described later. The rear end of the collar portion 9b is in contact with the step portion 1a provided on the barrel 1. (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 26a into contact with the step portion 25. (Choose one for your design)

By the way, a fastening 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'that contact the tapered surface fitted in the outer concave portion is internally provided. The coil spring 5 is interposed between the stepped portion formed at the rear end and the step portion and is pushed rearward. The core fixing chuck 3 is a synthetic resin molded product having excellent elasticity and strong abrasion resistance, and is constructed by combining two split cylindrical bodies. Also, when writing pressure acts on the core, the balls 4, 4'roll and the core fixing chuck 3 is tightened by the wedge effect to hold the core, but when pulling out the core forward, the spring of the coil spring 5 is By setting the force weakly, it is possible to use a force as small as several grams. By the way, the chuck case 2 is made of a resin molded product, and the tightening cylinder 6 is made of metal. Originally, the chuck case and the tightening cylinder are formed integrally, but the cost is high if they are made of metal due to the complicated processing. 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 taper portion are taken into consideration. As will be described later, according to the configuration of the present invention, the chuck case 2 and the tightening cylinder 6 can be integrated into a resin molded product.

A screw portion is formed on the inner diameter portion of the front end of the shaft cylinder 1, and a resin mouthpiece 13 having a tip pipe 14 fixed thereto is screwed onto the screw portion. The base 13 may be press-fitted into the inner diameter of the front end of the barrel 1. Further, the tip pipe may be integrally formed with the mouthpiece 13. Further, a guide slit 15 is formed in the center of the shaft side surface of the mouthpiece 13 slightly forward, and a payout body 16 is slidably fitted inside the mouthpiece 13. The feeding body 16 is provided with a holding chuck 18 fixed to the center thereof, and a locking piece 19 having a locking groove 19a is integrally formed on the outer periphery of the rear end side at a predetermined position corresponding to the guide slit 15. The locking piece 19 is fitted in the guide slit 15 and is slidable. 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 16 is at the frontmost position of the mouthpiece 13.

Further, the touching finger portion 20 is made of a resin having a ring shape, and a protrusion portion 20a is formed at a position corresponding to the locking groove 19a on the inner peripheral portion of the substantially tip end. The touching finger portion 20 is fitted to the outside of the mouthpiece 13, and the protrusion 20a is elastically fitted into the locking groove 19a and engaged with each other, so that the touching finger portion 20 and the feeding body 16 are integrally linked. Further, there is provided a space between the rear end of the touching finger portion 20 and the mouthpiece 13 for feeding out the touching finger.

In addition, inside the touching finger portion 20, a coil spring 21 is interposed between the touching finger portion 20 and the base 13, and the touching finger portion 20 is biased forward in a pressed state. The spring force of this spring may be larger than the force for pulling out the lead from the lead fixing chuck 3, so it 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 cylinder portion having a slit portion 7 is provided behind it. On the other hand, at the front end of the sliding tube 22, a ring-shaped projection 22a is formed on the outer diameter portion and a ring-shaped projection 22b is formed on the inner diameter portion, and the sliding tube 22 is attached to the rear portion of the chuck case 2. The protrusion 22b is fitted into the groove 2a by mutual elastic deformation. The front end of the sliding tube 22 is in contact with the rear end surface of the mouthpiece 13 and is in contact with the front end of the groove 2a of the chuck case 2. That is, the chuck case 2 is prevented from retreating against the biasing force of the coil spring 12.

[0012]

[Action]

 The feeding body 16 can be slid rearward by pulling the external touching finger portion 20 gently backward with a finger and causing the locking piece 19 to follow the guide slit 15. Then, when the finger is released, the holding chuck 18 holds the lead and returns to the front, so that the lead can be fed out. The amount of extension is the value of the interval at which the rear end of the touching finger portion 20 abuts the stepped portion of the mouthpiece 13 that faces it. When the lead is normally fed out, the rear end of the knock cover 29 may be knocked, and the lead guide 10 at the tip of the lead case 9 connected to the knock cover 29 has the flange 9b and the rear end of the sliding tube 22. 22c, the coil spring 12 interposed between the chuck case 2 and the chuck case 2 is compressed, and the tightening cylinder 6 integrated with the chuck case 2 is moved forward (the protrusion 11 forms the locking portion 8 as shown in FIG. 4). 8b, so that the core guide 10 and the chuck case 2 are interlocked with each other. When the lead projects from the tip pipe 14, the lead advances at the interval at which the tip of the tightening cylinder 6 collides with the step portion 16a of the feeding body 16. In this state, the chuck case 2 is prevented from advancing, 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 to move the lead fixing chuck. The hook 3 is released. (When the lead is not inserted through the lead fixing chuck 3, the lead falls at this time and abuts the holding chuck 18 or abuts on the rear end of the previous lead.) Next, the rear end knock of the knock cover 29 is released. Then, since the rear end of the protrusion 11 contacts the protrusion 8b, the chuck case 2 is retracted together with the lead case 9 while the fixed chuck 3 is opened while the lead is fixed to the holding chuck 18, and the chuck case 2 is retracted. When 2 is prevented from retreating at the front end of the sliding tube 22, only the lead case 9, that is, the lead guide 10 is retracted, and the protrusion 11 again passes over the protrusion 8b and is positioned between the protrusion 8a. By repeating the above, the lead is sequentially drawn out. (The lead advances by repeating the knocking operation even when the lead is in contact with the holding chuck 18 or the rear end of the front lead)

Further, when a strong writing pressure is applied with the lead protruding from the tip pipe 14, the chuck case 2 retracts together with the lead fixing chuck 3, so that the lead retracts to prevent core breakage. Further, 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. Also, when the lead retreats due to a strong writing pressure, the lead projects from the tip pipe 14 to its original state when the writing pressure is released, but the rear end of the lead fixing chuck 3 is in contact with the front end of the lead guide 10. Then, the amount of return of the core corresponds to the contact interval. Therefore, when the core projects long and the core retreats to the same plane as the tip pipe 14, the projection amount is adjusted to be approximately the same value as the above-mentioned contacting interval. That is, it is possible to provide the function of adjusting the length of the core protruding from the tip pipe 14 to an appropriate size by setting the contacting interval to an appropriate size. The load with which the chuck case 2 retracts is preferably set to about 400 to 700 g in consideration of proper writing work. That is, when a writing pressure higher than that is applied, the lead protruding from the tip pipe 14 is retracted (immersed in the lead pipe).

[0014]

[Effect of device]

 The present invention is as described above, and since there is no slit notched to the tip of the conventional shaft coupling, structural defects such as poor sliding of the finger and loosening of the screwed portion are eliminated. In addition, since the barrel, the base, the feeding body, and the touch finger are each formed as a synthetic resin molded product and the members are simplified, it is possible to significantly reduce the cost. In addition, although there is a problem of quality in the conventional complicated metal processing and screwed parts due to variations in processing, in the present application, since it can be formed by resin molding with a mold, there is no variation between members and there is an effect that quality is stabilized. To play. Also, when a strong writing pressure is applied, the core retracts into the tip pipe, preventing core breakage, and because an unreasonable load is not applied to the core fixing chuck, there is no deformation or wear associated with the core gripping function. It can be reduced and the life can be remarkably extended. Also, if 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 a vertical cross-sectional view of a finger-feeding type mechanical pencil according to an embodiment of the present invention, in which a part thereof is half-sectioned.

FIG. 2 is a vertical cross-sectional view of an entire touch-fing mechanical pencil according to an embodiment of the present invention, a part of which is faced with a judgment.

FIG. 3 is a front view showing the external appearance of a finger-feeding type mechanical pencil according to an embodiment of the present invention.

FIG. 4 is a perspective sectional view of an essential part showing an engaging portion between a lead guide and a chuck case of the present invention.

FIG. 5 is a view showing a fastening portion between the core case and the barrel of the present invention.

[Explanation of symbols]

 1 Shaft cylinder 1a Step 2 Chuck case 2a Groove 2b Collar 3 Core fixed 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 Base 14 Tip Pipe 15 Guide Slit 16 Feeding Body 16a Stepped Part 17 Center of Feeding Body 18 Holding Chuck 19 Locking Piece 19a Locking Groove 20 Touch Finger 20a Projection 21 Coil Spring 22 Sliding Pipe 22a Projection 22b Projection 22c Rear end 23 Slit 23a Slit 23b Small slit 23c Slit 24 24 Tapered 25 Step 26 26 Rib-shaped protrusion 26a Projection 27 Eraser stopper 28 Eraser 29 Knock cover 30 Clip 31 groove

Claims (1)

[Scope of utility model registration request] 1. A sharp holder which has a sufficient core holding force for writing due to the structure in which the lead fixing chuck 3 is tightened with a ball, but requires only a small force to pull out the lead from the lead fixing chuck 3. In the pencil, the main body of the shaft cylinder 1, the mouthpiece 13, the feeding body 16, and the touch finger portion 20 are formed as synthetic resin molded products, respectively, and the mouthpiece 13 is formed with a guide slit 15 at 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 payout body 16 fitted with a guide slit 15 and having a slidable locking piece 19. 1
The holding chuck 18 is provided at the center of the locking member 6 and the locking piece 1
A ring-shaped touching finger portion 20 that engages with the feeding member 16 and is integrally exposed to the outside of the mouthpiece 13 is provided inside the touching finger portion 20. A coil spring 21 is interposed between the contact fingers 20 so as to be pressed forward, and the coil spring 12 is attached via a slide tube 22 to the rear of the chuck case 2 for tightening the core fixing chuck 3 with a ball. The chuck case 2 is arranged together with the lead fixing chuck 3 when a strong writing pressure is applied to the tip of the lead.
A touch-fing type mechanical pencil, which is characterized in that it is configured to retract.