JP5022280B2 - Writing instrument - Google Patents

Description

  The present invention relates to a writing instrument that has a core protection pipe at the tip, and is drawn into the cylinder when not in use.

Like a mechanical pencil for drafting, a knock-type mechanical pencil provided with a stainless steel core protection pipe at the tip of a shaft cylinder is used to protect a thin core. However, if the lead protection pipe is left protruding from the tip of the shaft cylinder, the pipe may bend and become unusable when the mechanical pencil is dropped, or the pipe may penetrate or break clothing when carried. It was. Therefore, a mechanical pencil that allows the core protection pipe to be housed in the shaft cylinder is also known, but since the knock operation is possible, the knock member may be pushed without knowing and the core may protrude, Sometimes it was dangerous. Also known is a mechanical pencil with a structure in which the lead protection pipe at the front end and the knocking body at the rear end are simultaneously pulled into the shaft cylinder when not in use, and the core protection pipe and the knocking body are projected forward and rearward at the same time when in use However, since a complicated cylindrical cam or the like is required to draw the knock body into the shaft cylinder, the structure becomes complicated and cannot be obtained economically.
Japanese Utility Model Publication No. 61-39597 (claims for utility model registration, FIGS. 1 and 2)

  SUMMARY OF THE INVENTION An object of the present invention is to provide a writing instrument that can accommodate a core protection pipe in a shaft cylinder when not in use, disables a knocking operation, has a simple structure, and is economical.

  According to the present invention, a shaft cylinder, a connector provided with a core protection pipe at the tip thereof so as to be able to move back and forth so as to retract to a position in contact with an inner step formed in the shaft cylinder, and the connector in the retracting direction. A spring for energizing, a core feeding mechanism provided on the connector so as to feed the core from the tip of the core protection pipe by knocking a knock member protruding at the rear end of the shaft cylinder, and movable back and forth on the outer periphery of the shaft cylinder An exterior pipe having a rear end portion that is inserted into and opposed to the knock member, and a push pipe that is connected to the exterior pipe and is inserted into the shaft cylinder so as to be able to contact the rear end of the connector, When the exterior pipe advances, the connector is advanced between the shaft cylinder and the exterior pipe so that the core protection pipe protrudes from the tip of the axle cylinder, and the exterior pipe moves backward to retract the push pipe. The When the core protection pipe is accommodated in the shaft cylinder, the connector is allowed to move backward, and the rear end of the outer pipe moves to a position where the knock member is prevented from knocking. A writing instrument is provided which is provided with a guide member which regulates the retreat position and holds the exterior pipe at the advance position and the retreat position.

  According to the present invention, the guide member is slidably engaged with the groove having a guide groove extending in the longitudinal direction of the shaft tube, a holding groove extending in the circumferential direction at the front and rear ends of the guide groove, and the groove. The groove and the guide protrusion can be provided with either one member on the shaft tube and the other member on the exterior pipe. Furthermore, the above writing instrument is provided in which the groove and the guide projection are formed in the cam pipe and the cam tail plug, the cam pipe is provided in the rear portion of the shaft cylinder, and the cam tail plug is provided in the exterior pipe. The

  The present invention is configured as described above, and includes a shaft tube, a connector having a core protection pipe at the tip provided so as to be able to move back and forth so as to retreat to a position in contact with an inner step portion formed in the shaft tube, and the connector A spring for urging the shaft in the backward direction, a core feeding mechanism provided in the connector so as to feed the core from the tip of the core protection pipe by knocking a knock member protruding to the rear end of the shaft cylinder, and an outer periphery of the shaft cylinder An exterior pipe having a rear end portion that is fitted to be movable back and forth and faces the knock member, and a push pipe that is connected to the exterior pipe and inserted into the shaft cylinder so as to be able to contact the rear end of the connector. The connector is advanced between the shaft cylinder and the exterior pipe so that the core protection pipe protrudes from the tip of the shaft cylinder when the exterior pipe advances, and the exterior pipe is moved backward and pushed. Pa The outer sheath allows the connector to move backward so that the core protecting pipe is housed in the shaft cylinder when the stopper is retracted, and the rear end of the outer pipe moves to a position to prevent knocking of the knock member. A guide member that regulates the forward and backward positions of the pipe and holds the exterior pipe at the forward and backward positions is provided, so that the core protection pipe can be stored or projected only by moving the exterior pipe back and forth. Also, when the exterior pipe is retracted, its rear end moves to a position that prevents the knocking operation of the knocking member, so there is no risk of the knocking member being inadvertently knocked and can be carried safely. It is easy to operate, has a simple structure, and can be obtained economically.

  The guide member includes a guide groove extending in the longitudinal direction of the shaft tube, a groove portion having a holding groove extending in the circumferential direction at the front and rear ends of the guide groove, and a guide protrusion that slidably engages with the groove portion. One member of the groove and the guide projection is formed on the cam pipe, and the other member is provided on the cam tail plug. The cam pipe and the cam tail plug thus formed with the guide member are connected to the shaft tube and the exterior pipe. It is easy to manufacture, can be assembled efficiently, and is more economical.

1 to 3 show an embodiment of the writing instrument according to the present invention. The shaft cylinder 1 has an outer taper 2 at the tip, and a soft grip 3 on the outer periphery is formed integrally or separately. A small-diameter portion 5 is formed behind the flange 4 provided in the intermediate portion, and a hard or semi-rigid synthetic resin or metal grip is screwed onto the outer periphery of the small-diameter portion of the shaft tube, The outer taper may be screwed to the tip of the extending grip (not shown). As shown in FIG. 4, a rib portion 6 extending in the longitudinal direction, an inner step portion 7, and a screw portion 8 for screwing the outer taper 2 are provided inside the shaft tube 1.
A receiving groove 10 for locking the cam pipe 9 as shown in FIG. The cam pipe 9 is made of a metal pipe material, and has an elastic claw piece 12 with an engaging edge 11 facing inward so as to engage with the receiving groove 10 and a guide groove 13 extending in the longitudinal direction of the shaft tube. And the groove part 15 which has the holding groove 14 extended in the circumferential direction in the front-back end of this guide groove 13 is formed.

  A substantially cylindrical connector 16 having a sliding groove (not shown) fitted to the rib 6 formed on the outer periphery thereof is guided in the rib 6 and accommodated in the shaft tube 1 so as to be movable in the front-rear direction. The connector 16 is biased by a spring 17 so as to retract to a position where it abuts on the inner step portion 7. An inner taper 19 having a stainless steel core protection pipe 18 at the tip is connected to the front portion of the connector 16 by screwing or the like. The core protection pipe 18 is provided so as to protrude forward from an opening provided at the tip of the outer taper 2, and a core breaker 21 having an appropriate structure for elastically holding the core 20 is provided in the inner taper 19. Yes. The spring 17 for biasing the connector is provided between the outer taper 2 and the inner taper 19. An appropriate lead feeding mechanism is provided in the connector 16 so as to feed the lead 20 from the tip of the lead protection pipe 18 by a knocking operation. The outer taper and the inner taper can be formed of a suitable material such as a synthetic resin or a metal material. However, when both tapers are formed of a metal material, the outer taper and the inner taper are combined on the outer periphery of the inner taper for smooth operation. A resin sleeve may be attached to be inscribed in the outer taper (not shown).

  As the lead feeding mechanism, in the embodiment shown in the figure, a chuck guide 23 is fixed to the front end of a lead tank 22 inserted into the shaft cylinder and is housed in a connector so as to be movable back and forth, and a chuck 25 having a clutch 24 at the tip. Is inserted from the front of the connector and connected to the chuck guide 23, and the chuck guide 23 is urged rearward by a knock spring 26, and the core tank is knocked out to knock out the core so as to feed a known core feeding mechanism. Although it is used, a ball chuck type lead feeding mechanism or the like may be used. A knock member 27 is provided at a position protruding from the shaft cylinder 1 at the rear end of the lead tank 22. In FIG. 1, an eraser holder 28 is attached to the rear end opening of the lead tank 22, an eraser 29 is inserted into the eraser holder 28, and a knock cap 31 with a knock 30 attached to the rear end is attached to the outer surface of the eraser holder 28. Although the knock member 27 is configured to be detachably mounted on the head, other appropriate configurations can be adopted.

  An exterior pipe 32 is inserted on the outer periphery of the small diameter portion 5 of the shaft cylinder 1 so as to be movable back and forth, and a rear end portion 33 of the exterior pipe 32 faces the front surface of the knock 30 of the knock member 27. The distance between the rear end 33 of the exterior pipe 32 and the knock 30 is such that the exterior pipe is advanced and the core protection pipe 18 protrudes from the tip of the outer taper 2 to press the knock and perform the core feeding operation. It is formed at an interval that can be. Further, as will be described later, when the exterior pipe is retracted and the core protection pipe is accommodated in the outer taper, the rear end portion 33 is formed in a position close to the knock 30. An appropriate clip may be provided at an appropriate position of the exterior pipe 32 (not shown).

  A push pipe 34 inserted into the shaft tube 1 is connected to the exterior pipe 32 so as to be able to contact the rear end of the connector 16. In the embodiment, the push pipe 34 is connected and fixed in a cam tail plug 35 provided at the rear portion of the exterior pipe 32 by press fitting or the like. As shown in FIG. 6, the cam tail plug 35 has a flange 36 and a threaded portion 37 for screwing the exterior pipe 32 at the rear portion, and the front portion has an outer diameter that can be movably inserted into the cam pipe 9. A guide projection 39 is provided on the outer surface of the insertion portion 38 so as to be slidably engaged with the groove portion 15 formed in the cam pipe 9. Further, the insertion portion 38 is formed to be flexible by forming a slit 40 so as to facilitate assembly when inserted into the cam pipe 9.

  The connector 16 is advanced between the shaft cylinder 1 and the exterior pipe 32 so that the core protection pipe 18 protrudes from the tip of the shaft cylinder 1 via the push pipe 34 when the exterior pipe 32 advances. When the pipe 32 is retracted and the push pipe 34 is retracted, the connector 16 is allowed to move backward so that the core protecting pipe 18 is accommodated in the shaft tube 1 and the rear end portion 33 of the exterior pipe 32 is knocked. A guide member is provided that restricts the forward and backward positions of the outer pipe 32 so as to move to a position that prevents knocking of the member 27, and holds the outer pipe at the forward and backward positions. In the embodiment shown in FIG. 1 and the like, as shown in FIGS. 5 and 6, the guide member is provided with a groove 15 formed in the cam pipe 9 and the cam tail plug 35 so as to be slidably engaged with the groove 15. The forward and backward positions of the exterior pipe 32 are regulated by the length of the guide groove 13 extending in the longitudinal direction of the groove portion 15, and the exterior pipe 32 is surrounded by the forward and backward positions. The exterior pipe 32 is held in that position by rotating in the direction and inserting the guide protrusion 39 into the holding groove 14 extending in the circumferential direction.

  8 and 9 show another embodiment of the guide member. The cam pipe 41 has an elastic claw piece 42 having an engaging edge for engaging with the receiving groove 10 of the shaft tube, and an inwardly projecting guide. A protrusion 43 is provided. The insertion portion 45 of the cam tail plug 44 is provided with a guide groove 46 in which the guide protrusion 43 is slidably engaged, a groove portion 48 having a holding groove 47 and a slit 49, and the rear end of the embodiment shown in FIG. A threaded portion 51 for screwing the flange 50 and the exterior pipe is formed in substantially the same manner. The guide protrusion 43 is slidably engaged with the guide groove 46 extending in the longitudinal direction of the groove portion 48 and the holding groove 47 extending in the circumferential direction from the front and rear ends of the guide groove 46. Similarly to the example, the exterior pipe 32 is restricted in the forward position and the backward position, and is held in that position by rotating in the circumferential direction at the forward position and the backward position.

  In each of the above-described embodiments, the groove member and the guide protrusion are formed on the cam pipe and the cam tail plug. However, the guide member can be provided at another appropriate position, for example, the cam pipe and the cam tail plug. The guide member may be formed directly on the shaft tube 1 and the exterior pipe 32 without the above.

  10 to 13 show an embodiment in which a guide member is formed directly on the shaft cylinder 52 and the exterior pipe 53. As shown in FIG. 12, the shaft cylinder 52 has a guide groove 54 extending in the axial direction (longitudinal direction). A groove portion 56 having a holding groove 55 extending in the circumferential direction is formed at both ends of the guide groove 54, and a mountain-shaped small protrusion 57 is provided along the holding groove 55. Unlike the above embodiment, the groove is a recess formed in the outer surface of the shaft tube 52 and does not penetrate to the inner surface of the shaft tube. Further, an inclined surface 58 is formed at the rear end so as to guide the insertion of the guide projection of the exterior pipe, and a slit 59 extending in the longitudinal direction is provided so that it can be bent slightly during insertion. As shown in FIG. 10, a metal presser pipe 60 for reinforcement may be inserted into the inner surface of the rear part.

  As shown in FIG. 13, the exterior pipe 53 is integrally formed with a guide protrusion 61 that is slidably engaged with the groove portion 56 of the shaft cylinder 52 on the inner surface. Further, a small mountain-shaped small protrusion 62 is formed in the longitudinal direction of the guide protrusion 61, and the small protrusion 62 is formed in the holding groove 55 of the shaft cylinder 52 when the guide protrusion 61 enters the holding groove 55. The small projection 57 provided along the frictional friction is applied to give a weak resistance to the movement of the exterior pipe, and its position can be confirmed and locked. As in the above embodiment, the push pipe 34 attached to the cam tail plug 35 extends forward through the inside of the shaft tube.

  Referring to FIG. 11, when the outer pipe 53 is inserted from the rear end of the shaft cylinder 52 and the guide protrusion 61 provided on the outer pipe 53 is engaged with the groove portion 56 provided on the shaft cylinder 52, the above-described implementation is performed. As in the example, when the exterior pipe is moved in the longitudinal direction and the circumferential direction of the shaft tube, the movement can be controlled. In addition, you may make it provide a guide protrusion in the said shaft cylinder, and provide a groove part in an exterior pipe.

  In use, when the exterior pipes 32 and 53 are advanced, the push pipe 34 is advanced to push the connector 16 forward, and the core protection pipe 18 is protruded from the front end opening of the outer taper 2. When the guide protrusion is engaged with the holding groove by rotating in the circumferential direction, the core protection pipe can be held in a protruding state. Therefore, the knock member 27 is knocked and the lead is extended, and can be used in the state shown in FIG.

  Further, when not in use, when the exterior pipes 32, 53 are rotated in the opposite direction from the above-mentioned positions, the guide projections are returned from the holding grooves to the positions corresponding to the guide grooves, and the exterior pipes 32, 53 are retracted. As shown in FIG. 2, the core protection pipe 32 is pushed by the spring 17 and accommodated in the shaft cylinder 1, and the connector 16 hits the inner step portion 7 and is prevented from moving backward. When the exterior pipe is further retracted, the guide protrusion reaches the retracted position of the guide groove, and when the guide protrusion is engaged with the holding groove by rotating in the circumferential direction, the exterior pipes 32 and 53 are retained at the retracted position. . At this position, as shown in FIG. 3, the rear end portion 33 of the exterior pipe has moved to a position close to the front surface of the knock 30 of the knock member 27, so that the knock member 27 cannot be knocked. Therefore, in a non-use state, the core protection pipe 18 can be housed in the shaft tube 1 and the knocking operation of the knock member 27 can be disabled to prevent danger. In order to return from this state to the use state, the exterior pipes 32 and 53 are rotated in the opposite direction from the above-described positions, the guide protrusions are transferred from the holding grooves to the guide grooves, and then the above-described knocking operation is performed. .

1 is a sectional view showing a working state according to an embodiment of the present invention. Sectional drawing in the middle of accommodating a core protection pipe. Sectional drawing of a storage state. A shaft cylinder is shown, A is a top view, B is sectional drawing. A cam pipe is shown, A is a top view, B is a front view, C is sectional drawing, D is a development view of a cam part. A cam tail plug is shown, A is a plan view, B is a front view, and C is a cross-sectional view. The explanatory view showing the structure where the push pipe was press-fitted into the cam tail plug. Another embodiment of the cam pipe is shown, in which A is a plan view, B is a sectional view, and C is a longitudinal sectional view of a guide projection portion. The other example of a cam tail plug is shown, A is a top view, B is a front view, C is sectional drawing, D is a development view of a cam part. FIG. 6 is a partial cross-sectional view showing another embodiment. Explanatory drawing which shows operation | movement of the guide member of the Example shown in FIG. A part of shaft cylinder of the Example shown in FIG. 10 is shown, A is a top view, B is a front view, C is sectional drawing. 10 shows a part of the exterior pipe of the embodiment shown in FIG. 10, A is a cross-sectional view, B is a cross-sectional view showing a guide protrusion, and C is an enlarged view of a small protrusion.

Explanation of symbols

1, 52 Shaft cylinder 2 Outer taper 7 Inner step portion 9, 41 Cam pipe 13, 46, 54 Guide groove 14, 47, 55 Holding groove 15, 48, 56 Groove portion 16 Connector 17 Spring 18 Core protection pipe 19 Inner taper 22 Core tank 27 Knock members 32, 53 Exterior pipe 34 Push pipes 35, 44 Cam tail plugs 39, 43, 61 Guide protrusions

Claims (5)

  A shaft cylinder, a connector provided with a core protection pipe at the tip so as to move back and forth so as to retreat to a position in contact with an inner step formed in the shaft cylinder, and a spring for urging the connector in the retraction direction; A core feeding mechanism provided in the connector so as to feed the core from the tip of the core protection pipe by knocking a knock member protruding at the rear end of the shaft cylinder, and the knock inserted into the outer periphery of the shaft cylinder so as to be movable back and forth. An exterior pipe having a rear end facing the member, and a push pipe connected to the exterior pipe and inserted into the shaft cylinder so as to be able to contact the rear end of the connector, and between the shaft cylinder and the exterior pipe When the outer pipe advances, the connector is advanced through the push pipe so that the core protective pipe protrudes from the tip of the shaft. When the outer pipe moves backward and the push pipe moves backward, the core protection pad The forward and backward positions of the outer pipe are adjusted so that the connector is allowed to move backward so that the screw is housed in the shaft cylinder, and the rear end of the outer pipe moves to a position that prevents knocking of the knock member. A writing instrument, characterized in that a guide member is provided that regulates and holds the exterior pipe in that position in the forward and backward positions.   The guide member includes a guide groove extending in the longitudinal direction of the shaft tube, a groove portion having a holding groove extending in the circumferential direction at the front and rear ends of the guide groove, and a guide protrusion that slidably engages with the groove portion, 2. The writing instrument according to claim 1, wherein any one of the groove portion and the guide protrusion is provided on the shaft tube, and the other member is provided on the exterior pipe.   The shaft cylinder includes a cam pipe at a rear portion, the exterior pipe includes a cam tail plug at a rear portion, the groove portion is formed in the cam pipe, and the guide protrusion is provided in the cam tail plug. The writing instrument according to 2.   The shaft cylinder includes a cam pipe at a rear portion, the exterior pipe includes a cam tail plug at a rear portion, the guide projection is formed on the cam pipe, and the groove portion is provided on the cam tail plug. The writing instrument according to 2.   3. The writing instrument according to claim 2, wherein a small projection capable of frictionally engaging is formed on the shaft tube and the exterior pipe so as to give resistance to movement of the exterior pipe when the guide projection enters the holding groove. .

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