JP5193176B2 - mechanical pencil - Google Patents

Description

  The present invention relates to a mechanical pencil that can rotate the tip of a core worn with writing.

  With writing, the tip of the lead wears diagonally, and the thickness of the written line changes. In order to avoid such a phenomenon, it is only necessary to change the direction of the writing tip of the core by changing the shaft tube, but it is troublesome because the shaft tube must be regripped each time. Therefore, a mechanical pencil is known in which the tip of the core can be rotated without changing the shaft cylinder (see, for example, Patent Document 1). The mechanical pencil described in Patent Document 1 is configured so that the writing core can be released and gripped by the longitudinal movement of the chuck unit disposed in the shaft cylinder, and the writing core can be fed forward. The chuck unit is held in the shaft cylinder so as to be rotatable around the shaft core while holding the writing core, and the chuck unit is retracted by the writing pressure of the writing core. In accordance with the operation, a rotation drive mechanism for rotating the rotor is provided, and the rotation movement of the rotor is transmitted to the writing core via the chuck unit.

  That is, the mechanical pencil is configured such that the chuck unit is moved backward by the writing pressure without rotating the shaft cylinder, and the chuck unit is rotated in the shaft cylinder via the rotation drive mechanism. Since the lead case storing the lead is connected to the chuck unit, in order to rotate the chuck unit, the lead case must also be rotated within the shaft tube. For this reason, it is necessary to provide a rotation mechanism such as a chuck unit in the shaft cylinder and to provide a torque canceller or the like so as not to transmit the rotational force to the spring member or the like, which complicates the configuration.

  As described above, the conventionally known lead rotation type mechanical pencil is a mechanism that rotates the chuck unit holding the lead and the lead case (core tank) to which the chuck unit is attached within the shaft cylinder. The configuration is complicated. On the other hand, a mechanical pencil has been proposed in which the lead support portion and the hand support portion are separated so that the lead support portion rotates in one direction with respect to the hand support portion (see, for example, Patent Document 2). However, with this mechanical pencil, the structure of the core support part is unknown, and a straight member that is provided with sawtooth teeth on the upper surface of the lower stopper formed on the core support part and engages with the teeth at the tip of the hand support part A member with a tip is fixed, and each time the stopper is moved up and down by these members, the stopper is rotated in one direction. There is no certainty. Therefore, I don't know if this mechanical pencil was implemented.

Japanese Patent No. 4240417 (Claim 1, paragraph 0048, paragraph 0049, paragraph 0066, FIG. 1) Japanese Utility Model Publication No. 54-25339 (claims for utility model registration, Fig. 2 and Fig. 3)

  The problem to be solved by the present invention is that the core can be rotated without changing the shaft cylinder or rotating the chuck unit within the shaft cylinder, and the core can be easily used almost using the mechanism of the conventional mechanical pencil. It is to provide a mechanical pencil that can be rotated.

  According to the present invention, it has a cylindrical holding cylinder that is held when writing, and a mechanical pencil body that is configured to extend the core from the tip of the shaft cylinder, and the mechanical pencil body can be moved in the front-rear direction. And inserted into the holding cylinder so as to be rotatable in the circumferential direction, a front gear having forward teeth and a rear gear having rear teeth are formed on the inner surface of the holding cylinder, and the mechanical pencil body is disposed on the outer periphery of the mechanical pencil body. A front fixed gear having teeth that engage with the front gear when retreating and a rear fixed gear having teeth that engage with the rear gear when the mechanical pencil main body moves forward, and the sharpening when the pen pressure is applied. When the pencil body is allowed to move backward and the writing pressure is lost, the mechanical pencil body is moved forward so that the rear gear and the rear fixed gear are engaged with each other. A pen pressure spring that biases the sill body is provided, and the phases of the teeth of the front gear and the front fixed gear and the phases of the teeth of the rear gear and the rear fixed gear are rotated so that the mechanical pencil body rotates when the mechanical body moves back and forth. A mechanical pencil provided in a shifted manner is provided to solve the above-mentioned problems.

  Moreover, according to this invention, the said mechanical pencil which provided the grip and the main body cover in the outer periphery of the axial cylinder of a mechanical pencil main body as said holding | maintenance cylinder is provided.

  The present invention, as described above, has a cylindrical holding cylinder that is held when writing, and a mechanical pencil body that is configured to extend the core from the tip of the shaft cylinder, and the mechanical pencil body in the front-rear direction. It is inserted into the holding cylinder so as to be movable and rotatable in the circumferential direction, and a front gear having forward teeth and a rear gear having rear teeth are formed on the inner surface of the holding cylinder, and the sharp gear is formed on the outer periphery of the mechanical pencil body. A front fixed gear having teeth that engage with the front gear when the pencil body moves backward and a rear fixed gear having teeth that engage with the rear gear when the mechanical pencil body moves forward and writing pressure is applied. When the mechanical pencil body is allowed to move backward and the writing pressure disappears, the mechanical pencil body is moved forward so that the rear gear and the rear fixed gear are engaged with each other. A pen pressure spring is provided to urge the main body of the pencil, and the phase of the teeth of the front gear and the front fixed gear and the phase of the teeth of the rear gear and the rear fixed gear are rotated so that the mechanical pencil body rotates when the mechanical body moves back and forth. Since the offset is provided, the mechanical pencil main body can be rotated in the holding cylinder when the tip of the lead is brought into contact with or separated from the paper surface during writing, and the lead can be rotated accordingly. In addition, as the mechanical pencil body, the conventional knock mechanical pencil, side knock mechanical pencil, rotary mechanical pencil, and other well-known mechanical mechanical mechanisms can be used as they are. Can be obtained.

  If a grip or a main body cover is provided as the holding cylinder, it is easy to use as a mechanical pencil and the appearance is almost the same as a conventional mechanical pencil. Further, the front fixed gear is formed separately from the shaft cylinder, the mechanical pencil body is inserted into the holding cylinder, and then fitted to the shaft cylinder, and the front fixed gear is fixed by a taper member connected to the shaft cylinder. As a result, assembly is simple and economical.

Sectional drawing which shows one Example of this invention. FIG. 2 is a side view of a part of the mechanical pencil shown in FIG. 1 in a state where writing pressure does not act. FIG. 2 is a side view of a part of the writing state of the mechanical pencil shown in FIG. 1. Sectional drawing which shows a part of shaft cylinder of a mechanical pencil main body. The front fixed gear is shown, (A) is a side view, (B) half sectional view. Side view showing part of the grip in cross section Sectional drawing which shows the other Example of this invention. FIG. 8 is a side view showing a cross section of a part of the mechanical pencil shown in FIG. 7 where no writing pressure is applied. FIG. 8 is a side view of a part of the writing state of the mechanical pencil shown in FIG. 7. The relationship between the front and rear gears of the holding cylinder and the front fixed gear and rear fixed gear of the mechanical pencil body is shown. (A) shows the positional relationship before writing, (B) shows the front gear hits the front fixed gear at the start of writing. The contact state, (C) is an explanatory view when the gear is engaged and rotated by one tooth from the state (B), and (D) is an explanatory view when the writing tip is separated from the paper surface.

  FIG. 1 shows an embodiment of a mechanical pencil of the present invention, which has a mechanical pencil body 1 and a cylindrical holding cylinder 2 held by hand when writing. The mechanical pencil body 1 may be a normal knock mechanical pencil, a side knock mechanical pencil, a rotary feeding mechanical pencil, or any other appropriate mechanism. In the embodiment shown in FIG. 1, a knock mechanical pencil is used. Yes. That is, the mechanical pencil body 1 has a shaft tube 3, a tapered member 4 is connected to the tip of the shaft tube 3, and a clip 5 is provided on the outer periphery. In the shaft cylinder 3, a lead tank 7 for storing the lead 6, a chuck 8 fixed to the tip of the lead tank 7, a clutch 9 for controlling the opening and closing of the chuck 8, a mechanism for pressing the chuck and the like rearwardly. There is a spring 10, and an eraser 11 and a knock cover 12 are attached to the rear end of the lead tank 7. Further, the taper member 4 is provided with an inner step portion 13 that abuts when the clutch 9 advances, and a core holding member 14 such as a breaker rubber or an elastic piece that temporarily holds the fed core. These mechanisms are known mechanisms, and the core 6 can be drawn out from the tip of the taper member 4 and written by knocking the knock cover 12 protruding from the rear end of the shaft tube 3.

  As shown in FIG. 4, a step portion 15 is provided on the outer surface of the shaft cylinder 3, and a rear fixed gear 16 having forward teeth is formed on the outer peripheral surface in front of the step portion 15. A shaft cylinder in front of 16 is formed with a small diameter, and a positioning groove 17 that opens forward and extends in the axial direction is formed at the front end of the small diameter portion. A screw portion 18 is formed in front of the small diameter portion, and the taper member 4 is screwed. Then, before the taper member 4 is screwed, a front fixed gear 19 as shown in FIG. This front fixed gear 19 has teeth facing rearward, and a projection 20 is formed on the inner surface. By engaging the projection 20 with the positioning groove 17, the front fixed gear 19 is positioned so as not to rotate. Is fixed to the shaft tube 3.

  The mechanical pencil body 1 is inserted into the holding cylinder 2, can move in the front-rear direction within the holding cylinder 2, and can rotate. The holding cylinder 2 is positioned at least at a portion surrounding the rear fixed gear 16 and the front fixed gear 19 of the shaft cylinder. In the embodiment shown in FIGS. 1 to 3, the holding cylinder 2 is provided with an appropriate length that can be used as the grip 21. A spring receiving portion 22 is formed on the inner surface of the holding cylinder, and a rear gear 23 having rearward teeth to be engaged with the rear fixed gear 16 is provided on the rear surface of the receiving portion. A front gear 24 having forward teeth to be engaged with the front fixed gear 19 is formed on the end surface of the enlarged diameter portion in front of the receiving portion.

  Between the holding cylinder 3 and the mechanical pencil body 1, the mechanical pencil body 1 is moved forward (the holding cylinder is moved backward) to a position where the rear end of the holding cylinder 2 comes into contact with the step portion 15 of the mechanical pencil body 1. The holding cylinder 2 meshes with the rear gear 23 and the rear fixed gear 16 and allows the mechanical pencil body 1 to move backward (the holding cylinder moves forward) to mesh the front gear 24 with the front fixed gear 19. A writing pressure spring 25 for urging the mechanical pencil body 1 is provided. In the embodiment shown in FIG. 1, the writing pressure spring 25 is inserted between the receiving portion 22 and the protrusion 20 of the front fixed gear 19, but may be provided at other appropriate portions.

  The holding cylinder 2 can be formed to an appropriate length as described above, and is formed to be longer than the grip 21 shown in FIG. You can also FIG. 7 shows an embodiment in which a main body cover 26 is provided on the outer periphery of the shaft cylinder 3. The main body cover 26 is provided with a clip 27, and the main body cover 26 is applied to a step portion 28 provided at the rear of the shaft cylinder. It touches. The other configuration is the same as that of the embodiment shown in FIG.

  The teeth provided on the front gear 24, the front fixed gear 19, the rear gear 23, and the rear fixed gear 16 are provided in a mountain shape whose tips are inclined in the circumferential direction so that a rotational force is generated during meshing. When the mechanical pencil main body 1 moves back and forth and the front gear 24 and the front fixed gear 19 mesh with each other, or when the rear gear 23 and the rear fixed gear 16 mesh with each other, the mechanical pencil main body 1 rotates so as to rotate. The phase of the teeth of the gear 19 is shifted from the phase of the teeth of the rear gear 23 and the rear fixed gear 16.

  The relative movement of the gear will be described with reference to FIG. 10. FIG. 10A shows a state where the rear gear 23 of the holding cylinder 2 and the rear fixed gear 16 of the mechanical pencil body 1 are engaged with each other. (B) is a state in which the holding cylinder 2 moves to the left in the figure (the mechanical pencil body moves to the right) and the front gear 24 of the holding cylinder 2 and the front fixed gear 19 are in contact with each other. When the holding cylinder 2 further moves left in the drawing from the state of (B), the front gear 24 and the front fixed gear 19 of the holding cylinder 2 are engaged with each other, as shown in FIG. Since the phase of the teeth of the front fixed gear 19 is shifted from the phase of the teeth of the rear gear 23 and the rear fixed gear 16, the front fixed gear 19 is rotated by the front gear 24 of the holding cylinder 2. When the holding cylinder 2 moves rightward (the mechanical pencil body moves leftward) in the figure from the state shown in FIG. 10C, the front gear 24 moves away from the front fixed gear 19 as shown in FIG. The gear 23 meshes with the rear fixed gear 16 and returns to the state shown in FIG. Also at this time, the rear fixed gear 16 is rotated by the rear gear 23 due to the phase shift of the teeth.

  As described above, the mechanical pencil body 1 rotates in the holding cylinder 2 due to the meshing of the front and rear gears. Therefore, when writing, the pencil tip is applied to the mechanical pencil body 1 by applying the tip of the core to the paper surface, and the mechanical pencil. When the main body 1 is moved backward (the holding cylinder is moved forward), the front gear 24 and the front fixed gear 19 of the holding cylinder 2 are engaged with each other, so that the mechanical pencil main body 1 can be rotated as described above to rotate the core 6 ( 3 and 9). At this time, a gap 29 is formed between the rear gear 23 and the rear fixed gear 16 and between the rear end of the holding cylinder 2 and the step portion 15. When the tip of the lead is separated from the paper surface, the writing pressure disappears, and the pencil body 1 moves forward (the holding cylinder moves backward) by the writing pressure spring 25, and the front gear 24 of the holding cylinder 2 moves away from the front fixed gear 19. Since the rear gear 23 and the rear fixed gear 16 of the mechanical pencil body 1 mesh with each other, the mechanical pencil body can be rotated as described above to rotate the core (FIGS. 2 and 8). At this time, the relative movement between the holding cylinder and the mechanical pencil body 1 is stopped by the rear end of the holding cylinder 2 coming into contact with the step portion 15, and a gap 29 is formed between the front gear 24 and the front fixed gear 16. It is formed. Thus, the core 6 can be rotated without rotating the grip 21 or the main body cover 26 by bringing the core into contact with or away from the paper surface.

DESCRIPTION OF SYMBOLS 1 Mechanical pencil main body 2 Holding cylinder 3 Shaft cylinder 15 Step part 16 Rear fixed gear 19 Front fixed gear 21 Grip 23 Rear gear 24 Front gear 25 Writing pressure spring 26 Main body cover

Claims (6)

  It has a cylindrical holding cylinder that is held when writing and a mechanical pencil body that is configured to extend the core from the tip of the shaft cylinder. The mechanical pencil body can be moved in the front-rear direction and rotated in the circumferential direction. The front gear having a forward tooth and a rear gear having a rear tooth are formed on the inner surface of the holding cylinder, and the front gear is retracted on the outer periphery of the mechanical pencil body. A front fixed gear having teeth that engage with the back and a rear fixed gear having teeth that engage with the rear gear when the mechanical pencil body moves forward, and the mechanical pencil body moves backward when writing pressure is applied. When the writing pressure disappears, the mechanical pencil body is moved forward to urge the holding cylinder and mechanical pencil body to engage the rear gear and the rear fixed gear. And the phase of the teeth of the front gear and the front fixed gear is shifted from the phase of the teeth of the rear gear and the rear fixed gear so that the mechanical pencil body rotates when the mechanical pencil body moves back and forth. Mechanical pencil characterized by that.   The mechanical pencil according to claim 1, wherein the holding cylinder is a grip fitted to a shaft cylinder of a mechanical pencil body.   The mechanical pencil according to claim 2, wherein a step portion is formed on an outer periphery of the mechanical pencil body, and a rear end of the grip is provided so as to be able to contact the step portion.   The mechanical pencil according to claim 1, wherein the holding cylinder is a main body cover having a length extending along a shaft cylinder of the mechanical pencil main body.   The mechanical pencil according to claim 4, wherein a step portion is formed on an outer periphery of the mechanical pencil body, and a rear end of the main body cover is provided so as to be able to contact the step portion.   A rear fixed gear that has a knock type mechanical pencil body that is configured to extend the core from the tip of the shaft cylinder by knocking operation, has a stepped portion on the outer periphery of the shaft cylinder of the mechanical pencil body, and has forward teeth in front of it. Forming a positioning groove at the tip of the shaft tube, fitting a front fixed gear having teeth on the rear side of the shaft tube, and engaging a protrusion formed on the inner surface of the front fixed gear with the positioning groove. The front fixed gear is fixed to the outer periphery of the shaft cylinder in a non-rotatable state, and the holding cylinder held around the rear fixed gear and the front fixed gear is held in front of the stepped portion, A front gear having forward teeth to be engaged with the front fixed gear and a rear gear having rear teeth to be engaged with the rear fixed gear are formed on the inner surface of the holding cylinder, and when the writing pressure is applied, The mechanical pencil body is retracted. When the pencil pressure disappears, a pen pressure spring is provided to bias the holding cylinder and the mechanical pencil body so that the mechanical pencil body moves forward and meshes the rear gear and the rear fixed gear. A mechanical pencil characterized in that the phase of the teeth of the front gear and the front fixed gear is shifted from the phase of the teeth of the rear gear and the rear fixed gear so that the mechanical pencil body rotates when moving back and forth.

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