JP3162327U - mechanical pencil - Google Patents

Abstract

In a mechanical pencil having an automatic feeding mechanism, a cartridge-type mechanical pencil is provided which can easily replenish a core without removing a base provided at the tip of a main body. An automatic feeding mechanism is provided at the tip of a cartridge-type cylindrical main body. A tail plug 15 is detachably attached to the rear part of the main body. The tail plug 15 is formed with a pressing shaft 18 that can be inserted into the main body 2, and a concave portion 19 into which the core 4 enters is formed at the tip of the pressing shaft 18. To replenish the lead 4, the tail plug 15 is removed, the lead 4 is put into the main body 2, and then the tail plug 15 is fitted into the rear part of the main body 2. At this time, the core 4 is pushed by the pressing shaft 18 in a state where the rear end enters the recess 19, enters the automatic feeding mechanism, and protrudes from the front end of the main body. [Selection] Figure 4

Description

  The present invention relates to a mechanical pencil in which a lead is automatically drawn out with writing.

  An automatic feeding type mechanical pencil that automatically feeds a lead is known (for example, see Patent Document 1). These mechanical pencils are usually formed in a pencil shape, and a base (taper) is provided so as to be removable from the shaft tube, and an automatic feeding mechanism for automatically feeding a lead into the base is incorporated. And when replenishing the core, remove the base from the shaft tube, insert the core into the rear end of the automatic feeding mechanism part by hand from the rear end of the base, and push in until the core comes out from the front end of the base, At this time, it was necessary to push in with care so that the lead did not come out too much. In this way, the core is held by hand and fed to the automatic feeding mechanism, so if you hold the core several times or if it comes out of the tip of the base, fold the core by hand I had to adjust it.

  Further, since the base must be removed as described above, the entire shape cannot be formed into a cartridge type in which the tip portion corresponding to the base cannot be removed like the cartridge type refill of a ballpoint pen. It was difficult to use for a knock-type writing instrument.

Japanese Utility Model Publication No. 04-44389 (column 4, lines 9 to 12, FIG. 1)

  The problem to be solved by the present invention is that in a mechanical pencil that can automatically feed the lead when the lead is worn by writing, a new lead can be supplied to the automatic feeding mechanism without removing the base from the shaft tube. To provide a mechanical pencil that can be formed into a cartridge shape.

  According to the present invention, an automatic feeding mechanism that automatically feeds the lead with writing is provided at the front end of the cylindrical main body, and a tail plug is detachably fitted to the rear end of the main body. A mechanical pencil provided with a pressing shaft having a recess formed in the tail plug so as to be insertable into the main body and into which the rear end of the core enters, is provided.

  In the mechanical pencil of the present invention, the interval between the concave portion of the pressing shaft of the tail plug and the tip of the automatic feeding mechanism is formed to be equal to the length of the core when the tail plug is fitted to the main body. A mechanical pencil is provided.

  The present invention is configured as described above, and is provided with an automatic feeding mechanism at the front end of a cylindrical main body that automatically feeds the lead with writing, and a tail plug can be attached to and detached from the rear end of the main body. Since the press shaft having a recess formed so as to be inserted into the main body and into which the rear end of the core enters the tip plug is provided in the tail plug, in order to supply a new core into the automatic feeding mechanism, Remove the tail plug and insert the core into the main body, then insert the tail plug's pressing shaft into the main body, and fit the tail plug into the rear of the main body, the rear end of the core enters the recess of the pressing shaft, The core is pushed forward by the pressing shaft and advanced, and the tip is inserted into the automatic feeding mechanism and can be protruded from the tip of the automatic feeding mechanism. In this way, it is possible to replenish without holding one core by hand. When the lead is moved by the pressing shaft, the lead is not likely to be inclined in a state where the rear end is held in the concave portion, and is not broken because it is pushed straight. In addition, since it is only necessary to provide the tail plug at the rear part of the main body, there is no need to form a base detachably on the front part of the main body as in the conventional case, and the cartridge type refill structure with the front part formed in a sealed manner. If it is used for a writing instrument having a conventional knock mechanism, it can be used as a cartridge-type writing instrument in the same way as a ballpoint pen refill.

The half sectional view showing one example of the mechanical pencil of the present invention. Explanatory drawing in the case of replenishing a lead. Explanatory drawing of the state where the lead fell into the writing instrument body. The state which attaches a tail plug to a writing instrument main body is shown, (A) is the state which inserted the press shaft in the main body, (B) is each explanatory drawing of the state which fully fitted the tail plug in the main body. Sectional drawing which shows the Example which incorporated the cartridge type mechanical pencil in the axial cylinder which has a knock mechanism. FIG. 6 is a partial cross-sectional view showing another embodiment.

  FIG. 1 shows an embodiment of a cartridge-type mechanical pencil 1 according to the present invention. A tapered member 3 is provided at the tip of a cylindrical cartridge-type main body 2, and a core 4 is provided in the tapered member 3. An automatic feeding mechanism that automatically feeds forward is incorporated. Although the automatic feeding mechanism can be variously configured, the automatic feeding mechanism of the embodiment shown in the figure has a configuration substantially similar to the configuration described in Patent Document 1. That is, a slider 6 urged forward (in the distal direction) by a spring 5 is inserted at the tip of the taper member 3 so as to be movable back and forth, and a breaker that elastically temporarily holds the core 4 in the slider. An elastic member 7 such as rubber is provided. A chuck member 8 is provided to face the rear end of the slider 6 so as to be movable back and forth, and is urged backward (rear end direction) by the spring 5.

  The chuck member 8 is configured by combining a plurality of independent pieces, and is inserted into a clutch ring 9 whose diameter is increased from the rear to the front, and a ball 10 is interposed between the clutch ring 9 and the chuck member 8. ing. With this configuration, when the core 4 is temporarily held by the elastic member 7 of the slider 6 and moves forward together with the slider by the action of the spring 5, the chuck member 8 slightly moves to a position corresponding to the large diameter portion of the clutch ring and the core 4 However, when the lead 4 moves backward, the chuck member 8 returns to the position corresponding to the small-diameter portion to grip the lead and prevent the backward movement. The holding cylinder 11 of the clutch ring 9 has a protrusion 12 for preventing the chuck member 8 from falling off on the inner surface, the front part is attached to the taper member 3, and the main body 2 is attached to the rear part. The main body 2 and the taper member 3 are fixedly connected via the cylinder 11. A cylindrical guide pipe 14 is sandwiched between the rear end of the holding cylinder 11 and the inward protrusion 13 formed on the inner surface of the main body 2 to guide the insertion of the core 4.

  A tail plug 15 is detachably fitted in the rear part of the main body 2. The tail plug 15 has a head 16 having substantially the same diameter as the main body 2 and a pressing shaft 18 that extends forward from the head via a step portion 17 and can be inserted into the main body 2. A concave portion 19 into which the rear end of the core 4 enters is formed at the tip of the pressing shaft 18, and the concave portion 19 is formed in a substantially conical shape so that the core 4 can be held at the central portion of the main body 2. The distance between the recess 19 of the pressing shaft 18 and the tip of the automatic feeding mechanism provided on the taper member 3, that is, the tip of the protruding slider 5 in FIG. In the state, it is formed to be substantially equal to the length of the core 4.

  In order to replenish the core 4 into the main body 2 with the above configuration, the tail plug 15 is first removed from the main body 2 and the core 4 is put into the main body 2 as shown in FIG. Then, as shown in FIG. 3, the core 4 falls halfway in the main body 2, and the front end hits the rear end of the chuck member 8.

  Next, as shown in FIG. 4, the pressing shaft 18 of the tail plug 15 is inserted into the main body 2 and the rear end of the core 4 is inserted into the recess 19 (A in FIG. 4). In this state, the lead 4 is held in an upright state. Therefore, if the tail plug 15 is further pushed into the main body 2, the lead 4 is pushed into the chuck member 8 while being pushed by the pressing shaft 18 to advance the chuck member 8 and is tapered. The tail plug 15 stops when it reaches the leading end of the member, and the stepped portion 17 hits the rear end of the main body 2 (FIG. B). In this way, the lead 4 can be replenished without taking the trouble of inserting the lead directly into the chuck member.

  With the above configuration, the mechanical pencil of the present invention does not have to be configured so that the front portion of the main body is detachable, so that the whole can be formed into a thin cartridge type like a ballpoint pen refill. Therefore, it can be used for a knock-type writing instrument as shown in FIG. This writing instrument has a base 21 at the tip of the shaft tube 20, a grip 22 is provided on the outer surface of the shaft tube 20, and a knock-type delivery mechanism is provided at the rear. This delivery mechanism is a known mechanism, and has a fixed cam cylinder 24 that has a fixed cam on the inner surface of the cylindrical portion 23 and is inserted and fixed from the rear end of the shaft cylinder 20, and an inner side of the fixed cam cylinder 24. A knock shaft 25 to be inserted and a rotating cam cylinder 26 that rotates by the action of the fixed cam by the knock operation of the knock shaft 25 and moves in the front-rear direction are provided.

  The cartridge-type mechanical pencil 1 is accommodated in the shaft cylinder 20 and is urged rearward by a spring 27, and the tail plug 15 is in contact with the front end of the rotating cam cylinder 26. When the knock shaft 25 is knocked, the rotating cam cylinder 26 moves back and forth, and the tip of the cartridge type mechanical pencil 1 protrudes from the tip of the base 21 or can be used in a known manner. The shock absorbing spring is weaker than the spring 27 between the tail plug 15 of the cartridge-type mechanical pencil and the rotary cam cylinder 26 of the delivery mechanism, and weak enough to contact the rotary cam cylinder 26 in the written state. If 28 is provided (see FIG. 6), the impact and vibration received by the cartridge-type mechanical pencil can be reduced so that the lead is not automatically drawn out. The cartridge type mechanical pencil can be formed in various shapes other than the cartridge type, and may be formed in a pencil type.

DESCRIPTION OF SYMBOLS 1 Cartridge-type mechanical pencil 2 Main body 4 Core 15 Tail plug 18 Pressing shaft 19 Recess

Claims (5)

  An automatic feeding mechanism that automatically feeds the lead with writing is provided at the front of the cylindrical main body, and a tail plug is detachably fitted to the rear end of the main body, and the main body is attached to the tail plug. A mechanical pencil provided with a pressing shaft which is formed so as to be insertable therein and has a recess into which the rear end of the core enters.   2. The mechanical pencil according to claim 1, wherein the distance between the concave portion of the pressing shaft of the tail plug and the tip of the automatic feeding mechanism is formed to be equal to the length of the core when the tail plug is fitted to the main body. .   The mechanical pencil according to claim 1 or 2, wherein the recess is formed in a conical shape.   The mechanical pencil according to any one of claims 1 to 3, wherein the main body is formed in a cartridge type.   The cartridge-type mechanical pencil is housed in a barrel having a knock-type delivery mechanism at the rear, and is biased toward the delivery mechanism by a spring provided at the front, and between the delivery mechanism and the tail plug of the cartridge-type mechanical pencil. The mechanical pencil according to claim 4, wherein a shock absorbing spring weaker than the spring is provided.

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