JPS6347509Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotatable and retractable writing instrument that is convenient to carry and allows the writing part and the knob to be protruded or retracted as necessary by rotating the tip shaft and the cap. Conventionally, this type of writing instrument has a structure in which two cams are assembled to make the writing part and the notch part appear and retract, respectively, as seen in, for example, Japanese Utility Model Application Publication No. 55-115883 and Japanese Utility Model Application Publication No. 55-136587. is adopted. When two cams are used together in this way, it is necessary to adjust the phases of the two cams, which has the disadvantage of complicating the design and making assembly difficult. Therefore, the present invention, firstly, limits the number of cams used as the retracting mechanism to one, eliminates the trouble of adjusting the phase of two cams as in the past, and thus simplifies design and assembly. Second, in this type of sharp pencil, the notch part moves back and forth with respect to the lead pipe, so that the eraser that is generally attached to the inside of the notch part from the lead pipe can be moved. The lead storage space leading to the etc. will expand and contract, and especially if the tip is placed upward, the lead will fall from the lead pipe and the rear end will come into contact with the eraser, etc. When you rotate the cap and move the notch forward, the lead will be pushed forward by the eraser, etc., and if the front end of the lead comes into contact with the rear end of the lead held in the chuck, the lead will move forward. This is intended to solve problems that may occur, such as breakage or prevention of retraction of the notch.

The illustrated embodiment will be explained in detail below.
The structure and function for chucking and feeding out the lead are the same as those of a general knock-type mechanical pencil, so a description thereof will be omitted and only the gist of the present invention will be explained. First, FIG. 1 shows the state in which the writing instrument is used. A chuck 2 is disposed in the inner hole at the front end of the inner tube screw 1, and the chuck 2 protrudes forward of the inner tube screw 1.
A fastener 3 is fitted to the front end of the chuck 2, and a pipe relay 4 is caulked to the rear end of the chuck 2. A payout spring 5 is interposed between the pipe relay 4 and the inner step of the inner pipe thread 1, and the chuck 2 is normally tightened. pipe relay 4
A core pipe 6 is fixed to the rear end, and the inner pipe thread 1 is fixed to the rear end.
It protrudes from the rear end of the. The inner tube screw 1 has a small threaded portion 7 on the outer surface of the front end, and a mechanism stopper 8 to be described later and a hexagonal cross-section shaft portion 9 for preventing rotation slightly rearward.
Further, it has a large threaded part 11 which is screw-fitted with an outer pipe thread 10, which will be described later, further rearward, and an outer pipe thread stopper part 12 is fitted further rearward to form an inner pipe thread 1.
It has a groove portion 13 that limits the movement range of the groove, and reaches its retraction limit when the groove tip step portion (inner pipe thread stopper portion) 14 abuts against the outer pipe thread stopper portion 12. On the other hand, the inner pipe screw 1 has an elongated hole 15 on its inner surface into which the core pipe 6 is inserted movably in the axial direction, and a sliding piece 16 attached to the rear end of the core pipe 6 at the rear of the elongated hole 15 so as to be non-rotatable and axially movable. A rotation prevention hole (a hole with an octagonal to decagonal cross section) that can be fitted in a direction so as to be movable.
It has 17. The sliding piece 16 has a rotation prevention shaft part 18 having the same cross section as the rotation prevention hole part 17 and fitting in the same place at the front end, and a tip notch 20 of a cylindrical cam 19, which will be described later, on the outer surface near the rear end. A stepped shaft part has a sliding top cam protrusion 21 that removably locks the cam, and further has a core communication hole 23 at the rear end that communicates with the rear end hole 22 of the core pipe 6 inserted inside. It has 24. A core guide pipe 25 is fixed to the outer surface of the stepped shaft portion 24, a ball 26 is inserted into the core guide pipe, and a ball fitting hole 27, a core communication hole 28, and a core guide pipe are provided at the rear end of the core guide pipe. Core guide 3 with a series of holes 29 opened in the center
It is fixed at 0. The ball 26 is freely movable between the rear end of the sliding piece 16 and the ball insertion hole 27 of the core guide 30, and the outer diameter of the ball 26 is set to be slightly larger than the inner diameter of the core communication holes 23 and 28. ing. The rear end surface of the sliding piece 6 has an end portion lower than the center portion so that when the tip shaft 31 is directed downward, the ball 26 does not move to the end portion and block the core communication hole 23 in the center portion. It's so slanted. Further, the core guide 30 is arranged so that the ball 26 falls smoothly into the ball insertion hole 27 and closes the core communication hole 28 when the cap 40 is faced down.
The front end edge of 7 is tapered. Tip shaft 31
A mechanism stop 8 is crimped onto the inner surface of the tip, and an outer mouthpiece 3 is attached to the threaded portion 32 of the mechanism stop 8 that protrudes from the front shaft.
3 is removably attached, and a ring-shaped groove (mechanism retaining ring groove) 35 is provided behind the crimp portion 34 of the mechanism retainer 8 to prevent the outer tube screw 10 from moving in the axial direction, which will be described later. A hexagonal cross-sectional hole 9' is provided at the rear end of the inner surface of the stop 8. The outer tube screw 10 has a structure in which the whole or a part is divided into two parts in the axial direction, or it has a structure in which the whole or a part is divided into two parts and connected by a hinge or the like. It has a cylindrical body. The inner surface of the front end of the outer tube screw 10 has a ring-shaped protrusion 36 that fits into the mechanism retaining ring groove 35,
A large threaded portion 37 that fits with the inner tube thread 1 is provided on the approximately central inner surface, and a ring protrusion (outer tube thread stopper portion) 12 is further provided at the rear. The inner tube screw 1 has an inner cap 38 screwed to its tip small threaded portion 7, and is inserted into the inner hole of the mechanism stopper 8 with its hexagonal cross-section shaft portion 9 fitted into the hexagonal cross-section hole 9'. are doing. The outer tube screw 10 is screwed into the large threaded portion 11 of the inner tube screw 1 that protrudes behind the mechanism stopper 8,
The ring-shaped protrusion 36 is attached to the mechanism retaining ring groove 35.
A spring washer 39 is inserted between the front end surface of the ring-shaped protrusion 3 and the mechanism stopper 8.
6 is brought into contact with the rear wall surface of the mechanism retaining ring groove 35. The rear end of the outer tube screw 10 protrudes somewhat from the rear end of the tip shaft, into which a cap 4, which will be described later, is inserted.
0 is fixed. By the way, the inner tube screw 1 shown in FIG. 1 is shown in the most advanced state with respect to the front shaft 31. That is, the inner cap 38 is prevented from moving forward by abutting against the inner step 41 of the outer cap 33, and this contact prevents the inner cap 38 from wobbling. On the other hand, a cylindrical cam 19 is disposed in the inner hole of the rear half of the cap 40, and the cylindrical cam 19 has a cam slope 42 displaceable in the axial direction at its front end approximately on the circumference.
A notch 20 is provided at the front end of the cam slope 42 to removably engage the cam protrusion 21 of the sliding piece 16, and a guide for the cap 40, which will be described later, is provided on the outer surface. A guide groove 44 is provided in which the protrusion 43 is fitted to prevent rotation, and the rear part of the guide groove is a cylindrical part with a slightly reduced outer diameter. A knock cover 47 is removably attached to the outer surface. The inner hole of the cylindrical cam 19 has a large diameter section from the front end to approximately the rear end of the guide groove 44, and a small diameter section at the rear thereof, and communicates the small diameter section with the eraser fitting hole 46 mentioned above. A core guide spring 48 is provided with a step at the boundary, and has an extremely thin wire diameter and a pitch smaller than the core diameter between the step and the outer step of the sliding piece 16, and has an extremely weak spring force. is interposed. The cap 40 is provided with a guide protrusion 43 on its inner surface, and has a cutout portion 53 on the inner surface of the rear end into which the attachment portion 52 of the clip 51 is inserted.
A cap inner cylinder 54 having a shape is press-fitted and fixed,
The guide protrusion 43 is connected to the guide groove 4 of the cylindrical cam 19.
4 so that the cylindrical cam 19 is movable in the axial direction relative to the cap 40 but not rotatable in the circumferential direction, and the washer 49 and the cylindrical cam 19 are arranged in a state where they are in contact with the front end of the cap inner cylinder 54. The cylindrical cam 19 is biased forward by inserting a knock spring 50 between the outer step and the cam slope 42 of the cylindrical cam 19.
is always in contact with the sliding piece 16. The front end of the cap 40 is fixed to the rear end of the outer tube screw 10 as described above, and the front edge of the cap 40 is attached to the front shaft 31.
It is brought into approximate contact with the rear end edge of.

When the cap 40 is rotated clockwise with respect to the front shaft 31, the outer tube screw 10 also rotates integrally with the cap 40, and the inner tube screw 1, which is screwed onto the outer tube screw 10, is prevented from rotating by the mechanical stopper 8. Since it is blocked, move forward, and when the cap 40 is at its limit of clockwise rotation, the inner cap 38
The tip of the outer cap 33 protrudes from the tip opening of the outer cap 33. or,
At this time, as the cap 40 rotates, the cylindrical cam 19
The notch 20 provided at the front end of the cam slope 42 is engaged with the cam protrusion 21 of the sliding piece 16 when the cap 40 is at its right rotation limit. At this time, the cylindrical cam 19 is in the most retracted state with respect to the cap 40, causing the knob cover 47 fitted at its rear end to protrude toward the rear of the cap 40. Therefore, when the knock cover 47 is knocked, the knocking force is transmitted to the chuck 2 via the cylindrical cam 19, the sliding piece 16, the core pipe 6, and the pipe relay 4.
As the axis moves, the lead is drawn out and writing becomes possible.

Next, FIG. 2 shows the writing instrument in an unused state or in a carried state. The cap 40 is rotated to the left rotation limit with respect to the front shaft 31 from the state shown in FIG.
The counterclockwise rotation of the cap 40 causes the inner tube screw 1 to move backward and the inner cap 38 to be inserted into the outer cap 33, and at the same time, the counterclockwise rotation of the cap 40 causes the front end notch 20 of the cam slope 42 of the cylindrical cam 19 to move backward. When the cam protrusion 21 of the sliding piece 16 becomes unlatched, the cam slope 4
2 and the sliding piece 16 slide relative to each other, and the cam slope 42
The rearmost end of the cylindrical cam 19 comes into contact with the sliding piece 16, and as a result, the cylindrical cam 19 advances relative to the cap 40, causing the knob cover 47 fitted to the rear end to be recessed into the inside of the cap.

By the way, by rotating the cap 40 counterclockwise with respect to the front shaft 31 and advancing the cylindrical cam 19, the knob cover 4 is moved forward.
7 into the cap 40 with the tip shaft 31 facing upward, the ball 26 in the lead guide pipe 25 falls into the ball fitting hole 27 of the lead guide 30 and the lead guide 30 This will close the core communication hole 28. Therefore, the core inside the core pipe 6 does not fall backward from the core guide 30, and as the cylindrical cam 19 moves forward, it is pushed forward by an eraser or the like and its front end hits the rear end of the core held in the chuck 2. There is no need for the cores to fit together, and problems such as breakage of the core and the advancement of the cylindrical cam 19, that is, the retraction of the knock cover 47, are eliminated.

In addition, when replenishing the core pipe 6 with the core, the front shaft 3
You should do it with 1 facing down. That is, the ball 26 in the core guide pipe 25 moves toward the end due to the shape of the rear end surface of the sliding piece 16 and opens the core communication hole 23 in the center, so there is no problem in replenishing the core pipe 6 with the core. .

The present invention first involves inserting an inner tube screw that is integrated with a writing part that has a built-in chuck mechanism into the inner diameter part of an outer tube screw that is rotatably built in with respect to the tip shaft. On the other hand, the writing part is configured to be able to protrude and be stored, a sliding piece having a cam protrusion is provided at the rear end of the core pipe connected to the chuck, and a cylindrical cam having a cam slope is provided opposite to the sliding piece. The cap is constructed integrally with the notch portion, and is configured to be movable in the axial direction integrally with the rotation of the cap, which is connected to the outer tube screw, and the notch portion is configured to be movable in the axial direction by the action of the cylindrical cam. However, since the writing part is made to appear and disappear by mutual rotation of the outer tube screw and the inner tube screw, and the use of the cam is limited to one, the phase of the two cams can be adjusted as in the above-mentioned known example. This eliminates the trouble of doing so, simplifies design and assembly, and thus achieves the first objective. Next, the present invention connects a core guide pipe to the rear part of the sliding piece provided at the rear end of the core pipe, and then fixes the core guide to the rear end, and connects the core pipe to the center of the rear end of the sliding piece. The center of the core guide is provided with a core communication hole communicating with the inner hole of the cylindrical cam behind it, and a ball fitting hole is provided in the center of the core guide pipe. Insert a ball with a diameter larger than the inner diameter so that it can freely move, and align the rear end of the sliding piece so that the end is in the center so that the ball does not block the core communication hole of the sliding piece when the tip shaft is directed downward. The shape is lower than that of the cap, and the front edge of the ball insertion hole is tapered so that when the cap is turned downward, the ball falls into the ball insertion hole of the core guide and closes the core communication hole. As a result, the lead communication hole of the lead guide is blocked by the ball and the lead is prevented from falling from the lead pipe, especially when the tip of the lead is facing upward. There is no longer a lead that is pushed forward and moved, and therefore, the lead held in the chuck as in the conventional example above moves forward and collides with the lead behind it, resulting in breakage of the lead and sinking of the notch. This has the effect of avoiding troubles such as being blocked, thereby achieving the above second objective.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention.
The figure is a sectional view showing a state in which the writing part is protruded.
The figure is a sectional view showing a state in which the writing part is stored. 1...Inner tube screw, 2...chuck, 3...fastener, 4
...pipe relay, 5...feeding spring, 6...
Core pipe, 7...Small screw part, 8...Mechanism stop, 9...Hexagonal cross-section shaft part, 9'...Hexagonal cross-section hole, 10...Outer pipe thread, 11...Large thread part, 12...Outer pipe thread stopper part, 13 ...Groove portion, 14...Inner tube screw stopper portion, 15...Elongated hole, 16...Sliding piece, 17...Turn-stop hole, 18...Turn-stop shaft, 19...Cylindrical cam,
20... Notch, 21... Cam protrusion, 22... Rear end hole,
23... Core communication hole, 24... Stepped shaft portion, 25... Core guide pipe, 26... Ball, 27... Ball fitting hole, 28... Core communication hole, 29... Core guide hole, 30...
Core guide, 31... Tip shaft, 32... Threaded part, 33... Outer mouthpiece, 34... Crimping part, 35... Mechanism retaining ring groove part, 36... Ring-shaped protrusion, 37... Large screw part, 38
...Inner cap, 39...Spring washer, 40...
Cap, 41...inner diameter step, 42...cam slope, 4
3... Guide protrusion, 44... Guide groove, 45... Eraser, 46... Eraser fitting hole, 47... Knock cover, 48... Core guide spring, 49... Washer, 5
0...knot spring, 51...clip, 52...
Mounting part, 53...cut window part, 54...cap inner cylinder.

Claims (1)

[Scope of utility model registration request] A writing section with a built-in chuck mechanism and an integrated inner tube screw are inserted into the inner diameter of the outer tube screw, which is rotatable with respect to the tip shaft, and the writing section protrudes from the tip shaft by mutual rotation. , a sliding piece having a cam protrusion is provided at the rear end of the core pipe connected to the chuck, and a cylindrical cam having a cam slope facing the sliding piece is integrated with the knob part. A cap connected to the outer tube screw is configured to move integrally in the axial direction with respect to rotation, and a core guide pipe is connected to the rear part of the sliding piece, and further a rear end thereof is configured. A core guide is fixed to the rear end of the sliding piece, and the center of the rear end of the sliding piece has a core communication hole that communicates with the core pipe, and the center of the core guide has a core communication hole that communicates with the inner hole of the cylindrical cam behind it. Each ball insertion hole is provided, and a ball with a diameter larger than the inner diameter of each core communication hole is inserted into the core guide pipe so that it can freely move. In order to prevent the hole from being blocked, the rear end surface of the sliding piece is shaped so that the end is lower than the center, and when the cap is faced down, the ball falls into the ball insertion hole of the core guide, allowing the core to communicate. A rotating storage type writing instrument characterized in that the front end edge of the ball insertion hole is tapered so as to close the hole.