JP4995710B2 - mechanical pencil - Google Patents

Description

  The present invention relates to a mechanical pencil capable of rotating a writing core (replacement core) using writing pressure.

  When writing with a mechanical pencil, in general, the shaft tube is often used in a state slightly inclined with respect to the writing surface without being used in a state orthogonal to the writing surface (paper surface). In the case of writing with the shaft cylinder tilted in this way, the writing core becomes unevenly worn (decreased) as the writing progresses, so that a phenomenon occurs in which the drawn line becomes thicker than at the beginning of writing. Further, not only the thickness of the drawn line changes, but also the contact area of the writing core with respect to the writing surface changes, so that a phenomenon occurs in which the density of the drawn line changes as the writing progresses (the drawn line becomes thinner).

  In order to avoid the above-mentioned problem, if writing is performed while rotating the shaft cylinder, the sharp side of the writing core is written in contact with the paper surface sequentially, so that the drawn line becomes thicker according to the writing as described above. You can avoid problems such as. However, if it is attempted to write while rotating the shaft cylinder, the troublesome operation of holding the shaft cylinder as the writing progresses is required, and the writing efficiency is significantly reduced.

  In this case, when the outer casing of the shaft cylinder is formed in a cylindrical shape, it is not impossible to write while holding the shaft cylinder and rotating sequentially, but the outer casing is not cylindrical but has a protrusion on the middle. In the case of the attached design or the side knock type mechanical pencil, it is difficult to rewrite and write the shaft cylinder so as to sequentially rotate as described above.

Therefore, in order to solve the problems as described above, the chuck that grips the writing core is configured to retract by receiving the writing pressure, and the writing core is rotated together with the chuck by using the retracting operation. Patent Documents 1 and 2 disclose mechanical pencils having a mechanism.
Japanese Patent No. 3882272 Japanese Patent No. 3885315

  By the way, according to the mechanical pencils disclosed in Patent Documents 1 and 2 described above, the vertical protrusions and the vertical grooves are alternately arranged in the shaft tube, and the cam portion having the inclined surface so as to straddle them is annular. Is formed. Further, a rotor having protrusions intermittently formed in the circumferential direction is accommodated in the shaft cylinder. Then, the rotor is pushed up by largely retreating the writing core, and the protrusion of the rotor rides on the vertical protrusion formed on the cam portion in the shaft cylinder, and falls into the adjacent vertical groove through the inclined surface. The rotator is rotated by use, and the writing core is rotationally driven in conjunction with the rotation of the rotator.

  According to the mechanical pencil described above, when the rotor is rotated, a large retraction stroke of the writing core necessary for the rotor-side protrusion to get over the vertical protrusion formed in the shaft cylinder is required. For this reason, when the lead is partially reduced by writing, the rotor-side protrusion is moved into the shaft cylinder by applying a pressure higher than the normal writing pressure to the writing core and moving the rotor back in the shaft cylinder. A special operation is required to get over the formed vertical projections. Since this operation needs to be performed relatively frequently every time the lead is removed, there remains a problem of reducing the efficiency of writing.

  Therefore, in order to solve the problems of the mechanical pencils disclosed in Patent Documents 1 and 2 described above, the applicant of the present application slightly moves back and forwards the writing core accompanying writing (this is also referred to as cushioning operation in the following). .), A mechanical pencil that drives the writing core to rotate is filed as Japanese Patent Application No. 2006-156252.

  In the mechanical pencil according to the application, first and second cam surfaces are formed on each end surface of the rotor formed in a cylindrical shape, and the first cam surface is caused by a retreating operation of the rotor by writing pressure. Are brought into contact with and meshed with the first fixed cam surface. The second cam surface is brought into contact with and meshed with the second fixed cam surface by the forward movement of the rotor by releasing the writing pressure.

  In this case, as the rotor moves backward and forward, the rotor-side cam is sequentially meshed with the next cam tooth on the fixed side that is shifted by a half pitch with respect to one tooth of the cam, and the rotor rotates in one direction. The rotating operation is transmitted to the writing core via a chuck for gripping the writing core.

  According to the above-described configuration, it is possible to sequentially rotate the writing core by setting the retreating amount (cushion movement amount) of the core accompanying writing to about 0.05 to 0.5 mm. It is possible to provide a mechanical pencil excellent in practicality that does not reduce the efficiency.

  By the way, in the mechanical pencil having the above-described configuration, the first and second rotors on the rotor side are in the middle of the retreating operation of the rotor by the writing pressure and in the middle of the advancing operation of the rotor by the release of the writing pressure. A moment occurs when the cams are separated from the first and second fixed cams and the rotor becomes free in the rotational direction.

  Therefore, at this moment, the inventor may experience a rotational operation failure of the rotor due to a slight external force or vibration, that is, a state where the cam teeth on the rotor side do not get on the next cam teeth on the fixed side shifted by a half pitch. These results are confirmed in the prototype and verification results. Therefore, it is also expected that the writing core will be unable to rotate due to the above-described phenomenon continuing.

  The present invention has been made by paying attention to the above-mentioned problems inherent in mechanical pencils that use a cushioning action to rotate the writing core, and reliably drives the writing core to rotate using the cushioning action described above. It is an object of the present invention to provide a mechanical pencil with excellent operation reliability.

  The mechanical pencil according to the present invention, which has been made to solve the above-described problems, extends the writing core forward by releasing and gripping the writing core by the back and forth movement of the chuck disposed in the shaft cylinder. The chuck is held in the shaft cylinder so as to be rotatable around the shaft core in a state where the chuck is gripped, and the chuck by the writing pressure of the writing core is held. A mechanical pencil that is configured to transmit a rotational movement of the rotor to the writing core via the chuck. The rotational movement surface of the component housed in the shaft cylinder that is rotationally driven in conjunction with the rotation of the rotor or the rotor, and the rotational movement surface of the component are arranged opposite to the rotational movement surface. Adhesion medium between the fixed member is interposed a has a feature in that the viscous resistance in the rotational direction of the rotor by the adhesive medium is applied.

  In this case, as the adhesive medium, an adhesive grease is preferably used.

  And the preferable form of the said rotational drive mechanism is that the rotor which comprises this is formed in an annular | circular shape, and the 1st and 2nd cam surface is each formed in the one end surface and other end surface of the axial direction, First and second fixed cam surfaces disposed on the shaft cylinder side so as to face the first and second cam surfaces are provided, and the annular movement is caused by the retreating operation of the chuck by the writing pressure. The first cam surface of the rotor is brought into contact with and meshed with the first fixed cam surface, and the second cam surface of the annular rotor becomes the second fixed cam surface by releasing the writing pressure. And the second cam surface on the rotor side and the second cam surface in a state where the first cam surface on the rotor side meshes with the first fixed cam surface. The fixed cam surface of the cam The second cam surface on the rotor side is engaged with the second fixed cam surface and the first cam surface on the rotor side and the first One fixed cam surface is set so as to have a half-phase shift with respect to one tooth of the cam in the axial direction.

  In this case, there is provided a spring member that urges the second cam surface of the annular rotor to come into contact with the second fixed cam surface in a state in which the writing pressure is released. It is desirable that

  Further, in addition to the above-described configuration, a torque canceller is interposed between the rear end portion of the rotor and the spring member, and is formed in a cylindrical shape to generate slip between the rear end portion of the rotor. Preferably, the rotor is configured to prevent the rotational motion of the rotor from being transmitted to the spring member.

  In this case, in one preferable embodiment, a cam forming member that forms the first or second fixed cam surface is used as the fixing member, and the rotation moving surface of the rotor is opposed to the rotation moving surface. An adhesive medium is interposed between the cam forming members arranged in the manner described above.

  According to the above-described mechanical pencil according to the present invention, the rotor is reciprocated in the axial direction and driven to rotate by receiving the writing pressure, and the rotational movement of the rotor is transmitted to the writing core via the chuck. Therefore, it is possible to prevent the writing core from being unevenly worn as the writing progresses, and it is possible to solve the problem that the thickness of the drawn line and the darkness of the drawn line change greatly.

  In addition, the rotational movement surface of the component housed in the shaft cylinder that is rotationally driven in conjunction with the rotation of the rotor or the rotor, and a fixing member that is disposed to face the rotational movement surface In the meantime, since an adhesive medium represented by adhesive grease is interposed, viscous resistance is applied in the rotation direction of the rotor, so that the moment when the rotor becomes free in the rotation direction. In this case, it is possible to effectively prevent the rotor from rotating poorly due to a slight external force or vibration.

  Accordingly, it is possible to provide a mechanical pencil that can reliably execute the rotation operation of the writing core in conjunction with the writing operation.

  Hereinafter, a mechanical pencil according to the present invention will be described based on an embodiment shown in the drawings. 1 and 2 show a front half of a mechanical pencil that occupies the main part of the present invention. FIG. 1 is a perspective view showing the main part in a cutaway manner, and FIG. 2 shows a left half. It is the side view shown in the cross-sectional state.

  Reference numeral 1 indicates a shaft cylinder constituting the outline thereof, and reference numeral 2 indicates a tip portion attached to a tip end portion of the shaft cylinder 1. A cylindrical core case 3 is coaxially accommodated in the central portion of the shaft cylinder 1, and a chuck 4 is connected to the tip of the core case 3. The chuck 4 has a through hole 4a formed along its axis, and its tip is divided in three directions, and the divided tip is loosely fitted in a fastener 5 formed in a ring shape. It is installed in this way. The ring-shaped fastener 5 is attached to the inner surface of the tip of the rotor 6 formed in a cylindrical shape so as to cover the periphery of the chuck 4.

  A tip pipe 7 is arranged so as to protrude from the tip portion 2, and a base end portion of the tip pipe 7 is fitted to an inner surface of a tip portion of a support member 8 as an intermediate member located in the tip portion 2. Has been. The support member 8 is formed in a stepped shape in which a cylindrical portion is continuous so that the base end portion (rear end portion) side has a large diameter, and the inner surface of the base end portion is the tip of the rotor 6 described above. It is fitted to the peripheral side. A rubber holding chuck 9 having a through hole 9 a formed in the shaft core portion is accommodated on the inner peripheral surface of the support member 8 that supports the tip pipe 7.

  With the configuration described above, a straight core insertion hole reaching the tip pipe 7 through the through hole 4 a formed in the chuck 4 from the core case 3 and the through hole 9 a formed in the shaft core of the holding chuck 9. A writing core (replacement core) (not shown) is inserted into the linear core insertion hole. A coiled return spring 10 is disposed in the space between the rotor 6 and the chuck 4 described above. One end (rear end) of the return spring 10 is in contact with the end surface of the core case 3, and the other end (front end) of the return spring 10 is in contact with an annular end surface formed in the rotor 6. It is housed in the state. Therefore, the chuck 4 in the rotor 6 is urged in the backward direction by the action of the return spring 10.

  In the mechanical pencil shown in the drawing, the core case 3 moves forward in the shaft tube 1 by knocking a knocking portion, which will be described later, disposed at the rear end portion of the shaft tube 1, and the tip of the chuck 4 is tightened. By protruding from the tool 5, the gripping state of the writing core is released. Then, the release of the knocking operation causes the lead case 3 and the chuck 4 to retreat in the shaft cylinder 1 by the action of the return spring 10.

  At this time, the writing core is held in a through hole 9 a formed in the holding chuck 9. In this state, the chuck 4 retreats and the tip portion is accommodated in the fastener 5 so that the writing core is again held. That is, the writing core is released and gripped by the back and forth movement of the chuck 4 by repeating the knocking operation of the knocking portion, and the writing core acts so as to be sequentially advanced forward from the chuck 4.

  The rotor 6 shown in FIG. 1 has a large diameter portion with a thickened central portion in the axial direction, and a first cam surface (hereinafter referred to as a first cam surface) is formed on one end surface (rear end surface) of the large diameter portion. 6a is formed, and a second cam surface (hereinafter also referred to as a second cam) 6b is formed on the other end surface (front end surface) of the large-diameter portion. On the other hand, a cylindrical upper cam forming member 13 is attached to the rear end portion of the rotor 6 in the shaft cylinder 1 so as to cover the rear end portion of the rotor 6. A fixed cam surface (hereinafter also referred to as a first fixed cam surface or a first fixed cam) 13a is formed at the front end portion of the rotor 6 so as to face the first cam surface 6a of the rotor 6. Yes.

  Further, although not shown in FIG. 1 and shown in FIG. 2, a cylindrical lower cam forming member 14 is formed on the shaft cylinder 1 side so as to face the second cam surface 6 b of the rotor 6. A fixed cam surface (hereinafter also referred to as a second fixed cam surface or a second fixed cam) 14a is formed at the rear end portion in the axial direction. The relationship between the first and second cam surfaces 6a, 6b formed on the rotor 6, the first fixed cam surface 13a, and the second fixed cam surface 14a and their mutual actions are as follows. This will be described in detail later with reference to FIGS.

  FIG. 3 shows the mechanical pencil shown in FIGS. 1 and 2 up to the rear, and the representative parts shown in FIGS. 1 and 2 are denoted by the same reference numerals. As shown in FIG. 3, a cylindrical stopper 16 is fitted to the inner surface of the rear end of the upper cam forming member 13 formed in a cylindrical shape, and is formed in a cylindrical shape with the front end portion of the stopper 16. A coil-shaped spring member 18 is mounted between the torque canceller 17 that is movable in the axial direction.

  The spring member 18 acts to urge the torque canceller 17 forward, and the rotor 6 is configured to be pushed forward by being pushed by the torque canceller 17 receiving the urging force.

  According to the configuration described above, the rotor 6 is housed in the shaft cylinder 1 so as to be rotatable around the shaft core together with the chuck 4 while the chuck 4 grips the writing core. When the mechanical pencil is not used (in a case other than the writing state), the rotor 6 is biased forward via the torque canceller 17 by the action of the spring member 18, and FIGS. It will be in the state shown in.

  On the other hand, when a mechanical pencil is used, that is, when a writing pressure is applied to a writing core (not shown) protruding from the tip pipe 7, the chuck 4 moves backward against the urging force of the spring member 18. Accordingly, the rotor 6 also moves backward in the axial direction. Therefore, the first cam surface 6a formed on the rotor 6 shown in FIG. 1 and FIG. 2 is joined to the first fixed cam surface 13a to be engaged.

  4 (A) to 4 (C) and FIGS. 5 (D) and 5 (E) explain the basic operation of the rotation drive mechanism for rotating the rotor 6 by the above-described operation in order. 4 and 5, reference numeral 6 schematically shows the above-described rotor, and one end surface (the upper surface in the drawing) is continuously serrated along the circumferential direction. The first cam surface 6a is formed in an annular shape. Similarly, a second cam surface 6b that is continuously serrated along the circumferential direction is formed in an annular shape on the other end surface of the rotor 6 (the lower surface in the figure).

  On the other hand, as shown in FIGS. 4 and 5, the first fixed cam surface 13 a that is continuously serrated along the circumferential direction is also formed on the annular end surface of the upper cam forming member 13. A second fixed cam surface 14 a that is continuously serrated along the circumferential direction is also formed on the annular end surface of the lower cam forming member 14.

  The first cam surface 6 a, the second cam surface 6 b formed on the rotor, the first fixed cam surface 13 a formed on the upper cam forming member 13, and the second cam formed on the lower cam forming member 14. The cam surfaces formed in a sawtooth shape along the circumferential direction of the fixed cam surface 14a are formed so that their pitches are substantially the same. In FIG. 4 and FIG. 5, the circles drawn at the center of the rotor 6 indicate the rotational movement amount of the rotor 6.

  FIG. 4A shows the relationship among the upper cam forming member 13, the rotor 6, and the lower cam forming member 14 when the mechanical pencil is not used (in a case other than the writing state). In this state, the second cam surface 6b formed on the rotor 6 is located on the second fixed cam surface 14a side of the lower cam forming member 14 attached to the shaft cylinder 1, and the spring member 18 shown in FIG. It is contacted by the urging force. At this time, the first cam surface 6a on the rotor 6 side and the first fixed cam surface 13a are set so as to have a half-phase (half-pitch) offset with respect to one tooth of the cam in the axial direction. ing.

  FIG. 4B shows an initial state in which the writing pressure is applied to the writing core by using the mechanical pencil. In this case, as described above, the rotor 6 moves with the spring 4 as the chuck 4 moves backward. The member 18 is contracted and retracted in the axial direction. Thereby, the rotor 6 moves to the upper cam forming member 13 attached to the shaft cylinder 1.

  FIG. 4C shows a state in which the writing pressure is applied to the writing core by using the mechanical pencil, and the rotor 6 is in contact with the upper cam forming member 13 and retracted. In this case, the rotor 6 The formed first cam surface 6a meshes with the first fixed cam surface 13a on the upper cam forming member 13 side. Thereby, the rotor 6 receives a rotational drive corresponding to a half phase (half pitch) of one tooth of the first cam surface 6a. In the state shown in FIG. 4C, the second cam surface 6b on the rotor 6 side and the second fixed cam surface 14a are half phase (half pitch) with respect to one tooth of the cam in the axial direction. It is set to be in a shifted relationship.

  Next, FIG. 5D shows an initial state in which writing with the mechanical pencil is finished and the writing pressure on the writing core is released. In this case, the rotor 6 is moved by the action of the spring member 18 described above. Advance in the axial direction. Thereby, the rotor 6 moves to the lower cam forming member 14 side attached to the shaft cylinder 1.

  Further, FIG. 5E shows a state in which the rotor 6 has moved forward by contacting the lower cam forming member 14 due to the action of the spring member 18. In this case, the rotor 6 is formed on the rotor 6. The second cam surface 6b meshes with the second fixed cam surface 14a on the lower cam forming member 14 side. As a result, the rotor 6 is again subjected to rotational driving corresponding to a half phase (half pitch) of one tooth of the second cam surface 6b.

  Therefore, as indicated by a circle drawn at the center of the rotor 6, the rotor 6 receives the first and second cam surfaces 6 a, 6b is rotated corresponding to one tooth (one pitch), and the writing core 10 gripped by the chuck 4 is also rotated in the same manner.

  According to the mechanical pencil having the above-described configuration, the rotor receives a rotational motion corresponding to one tooth of the cam each time by reciprocation of the rotor 6 in the axial direction by writing, and the writing core is sequentially rotated by this repetition. The Therefore, it is possible to prevent the writing core from being unevenly worn as the writing progresses, and it is possible to solve the problem that the thickness of the drawn line and the darkness of the drawn line change greatly.

  Further, according to the mechanical pencil having the above-described configuration, the tip pipe 7 for guiding the writing core disposed so as to protrude from the tip 2 is fitted to the tip of the rotor 6 via the support member 8 functioning as an intermediate member. Therefore, the tip pipe 7 moves in the same direction via the support member 8 as the chuck 4 moves backward and forwards along with the writing operation. Therefore, even if the writing core moves slightly back and forth (cushioning) with the writing operation, the tip pipe that guides the writing core also moves in the same direction, so the relative movement in the axial direction between the tip pipe and the writing core Therefore, the protruding dimension of the writing core from the tip pipe can be kept constant.

  Further, since the tip pipe 7 is coupled to the rotor 6 via the support member 8, when the writing core is subjected to a rotational motion, the tip pipe is similarly subjected to the rotational motion. And the writing core will rotate together.

  Therefore, according to the mechanical pencil having the above-described configuration, it is possible to solve the problem that the protruding dimension of the writing core from the base member or the tip pipe changes each time during writing, and the user feels uncomfortable. Furthermore, it is possible to prevent the occurrence of core breakage due to cutting of the core in the tip pipe due to the change in the writing core protruding dimension from the tip pipe, and to eliminate the problem of contaminating the writing surface by scraping the core. Can do.

  The cylindrical torque canceller 17 that pushes the rotor 6 forward by receiving the biasing force of the coiled spring member 18 is between the front end face of the torque canceller 17 and the rear end face of the rotor 6. By causing a slip, the rotational movement of the rotor 6 caused by the repeated writing action is prevented from being transmitted to the spring member 18.

  In other words, the torque canceller 17 formed in a cylindrical shape is interposed between the rotor 6 and the spring member 18 to prevent the rotational motion of the rotor from being transmitted to the spring member. Thus, the problem that the rotating operation of the rotor 6 is obstructed can be solved by causing the spring member 18 to twist back (spring torque).

  Further, in the embodiment shown in the figure, as shown in FIG. 3, an annular concave groove is formed along the peripheral side surface of the torque canceller 17, and a rubber O-ring 19 is fitted therein. The O-ring 19 is formed on the inner peripheral surface of the upper cam forming member 13 when the torque canceller 17 moves backward due to the writing pressure or when the torque canceller 17 moves forward by releasing the writing pressure. It acts to slide and fulfill the function as a damper.

  That is, in the cushioning operation opposed to the urging force of the spring member 18 shown in FIG. 3, there is a problem that the feeling of being “heavy” or “flickering” is attached during writing, and the feeling is poor. Therefore, by arranging the O-ring 19 along the peripheral side surface of the torque canceller 17 as shown in FIG. 3 and utilizing the damper function thereby, the above-described problems can be reduced.

  6 and 7 are enlarged views of the overall configuration and the latter half of the mechanical pencil having the above-described functions, and FIG. 6 is a side view showing the left half in a sectional state. FIG. 7 is an overall cross-sectional view. In FIGS. 6 and 7, representative portions shown in the respective drawings already described are denoted by the same reference numerals.

  As shown in FIGS. 6 and 7, a knock bar 21 formed in a cylindrical shape is accommodated between the shaft tube 1 and the core case 3 on the inner surface of the shaft tube 1 on the rear end side. The knock bar 21 is configured to be urged rearward by a coiled spring member 22 disposed between the front end portion and the rear end portion of the stopper 16 described above. Moreover, the cylindrical part 23a which formed the clip 23 integrally in the rear-end part of the axial cylinder 1 is engage | inserted in the axial cylinder 1, By the step part 23b shown in FIG. 7 formed in this cylindrical part 23a, The knock bar 21 is configured to prevent the knock bar 21 from coming out to the rear end side of the shaft tube 1.

  The rear end portion of the knock bar 21 protrudes slightly rearward from the rear end portion of the cylindrical body portion 23a, and an eraser 24 is accommodated in the inner space of the rear end portion of the knock bar 21. Yes. A knock cover 26 constituting the knock portion so as to cover the eraser 24 is detachably attached so as to cover the outer peripheral surface of the rear end portion of the knock bar 21.

  On the other hand, immediately before the rear end portion of the knock bar 21, a replenishing port 27 for a writing core having a diameter smaller than the inner diameter of the knock bar 21 is formed as shown in FIG. The front end portion of the mouth 27 faces the rear end portion of the lead tank 3 with a slight gap G. That is, in this embodiment, the lead tank 3 is separated at the position of the gap G without being mechanically connected to the knock bar 21.

  In the above configuration, when the knock cover 26 is knocked, the front end portion of the replenishing port 27 hits the rear end portion of the lead tank 3 via the knock bar 21 and acts to push the lead tank 3 forward as it is. To do. As a result, the chuck 4 moves forward as described above and acts so that the writing core is fed out from the tip pipe 7. When the knocking operation is released, the knocking bar 21 is retracted by the action of the spring member 22, and the knocking bar 21 is locked by a step part 23 b formed on the inner surface of the cylindrical part 23 a that supports the clip 23.

  According to the above-described configuration, the gap G is formed between the front end portion of the writing core replenishment port 27 formed on the rear end portion side of the knock bar 21 and the rear end portion of the core tank 3. Even in the backward movement of the chuck 4 and the lead case 3, the rear end portion of the lead case 3 does not collide with the front end portion of the supply port 27. Further, due to the presence of the gap G, the rotation operation of the lead case 3 by the above-described rotation drive mechanism is not transmitted to the knock cover 26 side.

  In other words, even if the knock cover 26 is rotated by a fingertip or the like, the rotation operation is not transmitted to the above-described rotation drive mechanism via the lead case 3, and the knock cover 26 is rotated darkly. It is possible to eliminate the problem that the rotation drive mechanism is disturbed.

  Further, by forming the gap G as described above, even when the knock cover 26 protruding from the rear end portion of the shaft cylinder is in contact with something, the rotation driving mechanism for rotating the writing core is used. The problem of stopping the function can be solved.

  By the way, in the mechanical pencil having the above-described configuration, as already described, in the middle of the retreating operation of the rotor 6 by the writing pressure and in the middle of the advancing operation of the rotor 6 by releasing the writing pressure, the rotor side When the first and second cams 6a and 6b are separated from the first and second fixed cams 13a and 14a, the rotor 6 becomes free in the rotational direction.

  Therefore, at the moment when the gear becomes free, the rotor rotates poorly due to a slight external force, vibration, or the like, that is, the cam teeth on the rotor 6 side do not get on the next cam teeth on the fixed side shifted by a half pitch. It has been confirmed that it is expected that the writing core will be unable to rotate as the above-mentioned phenomenon continues continuously.

  FIG. 8 shows an example of countermeasures for solving the above-mentioned problem. FIG. 8 shows an enlarged cross-sectional view of the portion A in FIG. 6 already described, and the same portions are denoted by the same reference numerals. Yes. In addition, in FIG. 8, description of the axial cylinder 1 which comprises an outline is abbreviate | omitted.

  That is, as shown in FIG. 8, the rotor 6 has a rotational movement surface (cylindrical outer peripheral surface) 6A on the rear end side thereof rotatably supported by the upper cam forming member 13 formed in a cylindrical shape, An adhesive medium 20 typified by adhesive grease is interposed between the rotational movement surface 6A of the rotor 6 and the upper cam forming member 13 as a fixing member arranged to face the rotational movement surface. ing. That is, the adhesive grease 20 is substantially applied to the rotational movement surface 6A of the rotor 6.

  In this embodiment, the upper cam forming member 13 is formed with a plurality of window-like spaces along the circumferential direction by the notches 13A, and is formed by the notches 13A. A part of the rotational movement surface 6A of the rotor 6 is exposed in the window-shaped space.

  The window-shaped space formed by the notch 13A can be used to inject the adhesive grease 20 between the rotational movement surface 6A of the rotor 6 and the upper cam forming member 13. In addition, the window-shaped space portion also functions to serve as a grease reservoir capable of accumulating excess grease.

  According to the configuration described above, the adhesive grease 20 is interposed between the rotational movement surface 6A of the rotor 6 and the upper cam forming member 13 disposed to face the rotational movement surface. The adhesive grease 20 acts to provide viscous resistance in the rotation direction of the rotor 6. In this case, as the adhesive grease used in the above-described embodiment, it is desirable to use a grease having a consistency of 100 to 400. As the adhesive grease, for example, trade name of Shin-Etsu Chemical Co., Ltd. “Shin-Etsu Silicone Grease” product numbers: G330 to 334, G340 to 342, G351 to 353, and G631 to 633 can be suitably used.

  Thus, as described above, at the moment when the rotor 6 becomes free in the rotation direction, the rotor 6 is held by the adhesive grease 20 even when, for example, vibration is received. Further, when the first or second cam of the rotor 6 meshes with the first or second fixed cam, the rotation is not hindered.

  Therefore, according to the mechanical pencil described above, the degree of rotation failure of the rotor due to external force or vibration can be greatly reduced, and this type of mechanical pencil that uses the cushion action to rotate the writing core. The reliability of the operation can be improved.

  In the embodiment described above, adhesive grease is interposed between the rotational movement surface 6A on the rear end side of the rotor 6 and the upper cam forming member 13, For example, as shown in FIG. 8, even if the adhesive grease is interposed between the rotational movement surface 6B on the front end side of the rotor 6 and the lower cam forming member 14, the same effect is obtained. be able to. Furthermore, the adhesiveness between the rotational movement surface of the component housed in the shaft cylinder that is rotationally driven in conjunction with the rotation of the rotor, and the fixed member that is disposed to face the rotational movement surface Similar effects can be obtained by interposing a medium.

  In the above description, an example of using an adhesive grease as an adhesive medium is shown, but instead of this, an adhesive medium such as castor oil or other high-viscosity oil, liquid rubber, low molecular weight resin, or clay is used. It can also be used.

It is the perspective view which fractured | ruptured and showed a part of front half part of the mechanical pencil concerning this invention. It is the side view which showed a part in the state of a section similarly. It is the side view which showed the part shown to near rear part about the same mechanical pencil in the cross-sectional state. FIG. 4 is a schematic diagram for explaining the rotational driving action of the rotor mounted on the embodiment shown in FIGS. 1 to 3 in order. FIG. 5 is a schematic diagram for explaining the rotational driving action of the rotor following FIG. 4. It is the side view which showed a part of whole structure in embodiment shown in FIGS. 1-3 in the cross-sectional state. It is sectional drawing which expanded and showed the latter half part similarly. It is sectional drawing which expanded and showed the A section in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Mouth part 3 Core case 4 Chuck 5 Fastener 6 Rotor 6a 1st cam surface 6b 2nd cam surface 6c Display part 6A Rotation movement surface 6B Rotation movement surface 7 Tip pipe 8 Support member 9 Holding chuck 10 Return spring 13 Upper cam forming member 13a First fixed cam surface 13A Notch portion 14 Lower cam forming member 14a Second fixed cam surface 16 Stopper 17 Torque canceller 18 Spring member 19 O-ring 20 Adhesive grease (adhesive medium)
21 knock bar 22 spring member 23 clip 26 knock cover

Claims (6)

The writing core is released and gripped by the back and forth movement of the chuck disposed in the shaft cylinder, so that the writing core can be fed forward, and the chuck holds the writing core. Rotation that is held in the shaft cylinder so as to be rotatable about the shaft core, and that rotates the rotor by retreating and moving forward of the rotor through the chuck by the writing pressure of the writing core. A mechanical pencil comprising a drive mechanism and configured to transmit the rotational movement of the rotor to the writing core via the chuck;
Between the rotational movement surface of the component housed in the shaft cylinder that is rotationally driven in conjunction with the rotation of the rotor or the rotor, and a fixed member disposed opposite to the rotational movement surface A mechanical pencil characterized in that an adhesive medium is interposed and a viscous resistance is imparted in the rotational direction of the rotor by the adhesive medium.   The mechanical pencil according to claim 1, wherein the adhesive medium is an adhesive grease. The rotor constituting the rotation drive mechanism is formed in an annular shape, and first and second cam surfaces are formed on one end surface and the other end surface in the axial direction, respectively, and the first and second cams are formed. First and second fixed cam surfaces disposed on the shaft tube side so as to face each other,
Due to the retraction operation of the chuck by the writing pressure, the first cam surface in the annular rotor is brought into contact with and meshed with the first fixed cam surface, and the release in the writing pressure releases the chuck in the annular rotor. A second cam surface is configured to abut against and mesh with the second fixed cam surface;
In a state where the first cam surface on the rotor side is engaged with the first fixed cam surface, the second cam surface on the rotor side and the second fixed cam surface are in the axial direction. The second cam surface on the rotor side is engaged with the second fixed cam surface and the first cam surface on the rotor side and the first 3. The mechanical pencil according to claim 1, wherein the fixed cam surface of 1 is set to have a half-phase shifted relationship with respect to one tooth of the cam in the axial direction.   A spring member that urges the second cam surface of the annular rotor to engage with the second fixed cam surface in a state where the writing pressure is released; The mechanical pencil according to claim 3.   Between the rear end portion of the rotor and the spring member, a torque canceller that is formed in a cylindrical shape and generates slip between the rear end portion of the rotor is interposed, and the rotational movement of the rotor is performed. The mechanical pencil according to claim 4, wherein the mechanical pencil is configured to prevent transmission to the spring member.   A cam forming member that forms the first or second fixed cam surface is used as the fixing member, and the rotational movement surface of the rotor and the cam forming member arranged to face the rotational movement surface The mechanical pencil according to any one of claims 3 to 5, wherein an adhesive medium is interposed therebetween.

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