JP4565729B2 - mechanical pencil - Google Patents

Description

[0001]
[Industrial application fields]
The present invention is configured such that the core is gripped and written by the chuck provided in the shaft cylinder, the core is fed out from the tip of the tip portion with a small stroke of the chuck, and the core is accommodated in the tip portion with a large stroke. It relates to the improvement of mechanical pencils.
[0002]
[Prior art]
Conventionally, this type of mechanical pencil is connected to the core case connected to the chuck, and the knock part protrudes from the rear end of the shaft. The knock part is moved by a small stroke to engage the chuck with the first fastening ring. The lead is protruded from the shaft tip, and the shaft is moved with a large stroke so that the chuck is engaged with the second fastening ring and retracted, and the lead is stored from the shaft tip. That is, the above stroke difference is made with care, and there is a problem that the lead is stored when it is desired to feed the lead.
In order to discriminate between the small stroke and the large stroke, there is also known one provided with a stroke display on the knocking portion or the like, but this relies on moderate or manual, and the inconvenience difference has not been eliminated.
[0003]
In order to solve the above problems, the chuck connected to the core case in the shaft cylinder is urged toward the retracting side by a spring, and when the chuck is engaged with the first fastening ring, the core is gripped and the chuck is The lead is released when it moves forward and disengages from the tightening ring, and when the chuck is further advanced, the tip of the chuck is engaged with the second fastening ring positioned inside the tip of the shaft to grip the lead. In the mechanical pencil constructed so that it can be retracted as it is, the rear end of the knock portion protruding from the rear end of the rear shaft is moved in the axial direction, and the chuck is disengaged from the first fastening ring and the core is fed out from the shaft tip. In addition, the shaft cylinder is configured to be rotatably connected to the front shaft and the rear shaft, and when the rear shaft is rotated with respect to the front shaft by forming a cam portion between the core case and the rear shaft, Engage the tip of the chuck with the tightening ring 2 That was to house than Jikusaki is known.
Although this method makes it possible to discriminate between small strokes and large strokes by adjusting the amount of time and the amount of time, and the problem of malfunction has been solved, there is a new problem that the operability is troublesome.
[0004]
[Problems to be solved by the invention]
It is possible to provide a mechanical pencil that is easy to distinguish between a small stroke and a large stroke and has good operability at low cost.
[0005]
[Means for Solving the Problems]
The present invention has the following configuration in order to achieve the above-described problems. The mechanical pencil according to claim 1 is configured such that the chuck connected to the core case in the shaft cylinder is biased toward the drawing side by a spring, and the chuck is held when the chuck is engaged with the first fastening ring. The lead is released when it is moved forward and removed from the tightening ring, and further when the chuck is advanced and the tip of the chuck is engaged with the second fastening ring within the tip provided at the front end of the shaft cylinder. In a mechanical pencil that is gripped and configured to be retractable in its core gripping state, a knock portion provided at the rear end of the core case is retracted forward with respect to the shaft tube, and the chuck is first tightened. The core is extended from the tip of the tip by engaging and disengaging from the ring, and the damper is actuated immediately before the tip of the chuck engages with the second fastening ring, and the knock force increases rapidly. Ahead Inner stage but the core that protrudes from the tip of the snout portion so as to accommodate in the snout portion disengaged, and the projection provided on the front outer circumference of the lead case, the slide cylinder is fitted from the front of the lead case A step where the rear end of the slide cylinder is locked to the protrusion of the core case with the spring for the damper springing between, and the front end of the slide cylinder is provided on the shaft cylinder along with the core case. It is characterized in that only the lead case moves forward and the damper is actuated when it comes into contact with the part.
[0006]
A mechanical pencil according to a second aspect of the present invention is the mechanical pencil according to the first aspect, wherein a protrusion provided on the front outer periphery of the core case and a slide cylinder fitted to the core case from the front thereof. The rear end of the slide cylinder is locked to the protrusion of the core case with the spring for the damper springing between the inner stage and the front end of the slide cylinder to the shaft cylinder. At the time of contact with the provided step, only the lead case moves forward and the damper is activated.
[0007]
【Example】
1 to 3 show an embodiment of the present invention.
The shaft tube 1 is a tube body having a screw portion on the outer periphery of the tip, and the front end portion 2 is screwed to the screw portion, and the front outer periphery of the shaft tube 1 held at the time of writing and the rear outer periphery of the front end portion. A grip 11 made of rubber or thermoplastic elastomer is provided.
[0008]
The chuck 3 is disposed in the inner hole of the front end portion of the shaft cylinder 1 with the first fastening ring 5 fitted on the outer periphery of the core gripping portion at the front end, and the rear end of the chuck 3 is in the core case within the shaft cylinder 1. 4, a spring 8 is laid between the front step portion 1a of the shaft tube and a step portion 4a provided on the rear outer peripheral portion as appropriate from the front end of the core case 4, so that the chuck 3 is attached to the shaft tube 1. It is energized on the pull-in side.
[0009]
The tip portion 2 has a tip pipe portion 2a (a pipe that is integral with the tip portion or a separate pipe may be attached) through which the lead is inserted, and a holding chuck 2b that frictionally holds the lead at the tip of the inner diameter portion ( A rubber holding chuck may be attached or formed integrally with the resin tip, and a second fastening ring 7 is fitted behind the second fastening ring 7, and the second fastening ring 7 is predetermined. A step ring where the front end of the second tightening ring 7 abuts and a stop ring 6 where the rear end of the second tightening ring 7 abuts are fixed so as to be able to move back and forth at intervals of. (In the case of a resin-made mouth part, it can be formed as an integral protrusion.) The first fastening ring 5 moves back and forth within a range in contact with the rear end of the retaining ring 6 of the mouth part 2. To do. The interval is a main factor for determining the lead feeding amount. (If there is no stop ring, a stepped part is formed.)
[0010]
Also, a damper spring 10 is repelled between the protrusion 4b provided on the front outer periphery of the core case 4 and the inner stage 9a of the slide cylinder 9 fitted on the outer periphery of the core case 4 from the front. In this state, the rear end of the slide cylinder 9 is locked to the protrusion 4 b of the core case 4.
[0011]
As shown in the figure, the slide cylinder 9 is a cylinder having an inner step 9a at the front end of the inner hole, and a slit portion 9b opened at the rear end is formed on the side of the cylinder. The slit portion 9b is formed with a tapered portion 9d that narrows toward the front, a step portion 9c is formed at the front end of the tapered portion 9d, and a rectangular hole portion 9e whose front end is closed is further formed in front of the step portion 9c. Formed. Moreover, although the slit part 9b is provided in two places on balance, it may be one place or three places.
The protrusion 4b provided in the core case 4 is shaped to be fitted into the slit 9b, and the protrusion 4b elastically expands the tapered portion 9d to protrude from the front surface of the step portion 9d. 4b is locked, and the slide cylinder 9 can be retracted with respect to the core case 4 at an interval at which the protrusion 4b contacts the front end of the hole 9e. The means for locking the slide cylinder to the core case is not limited to the above embodiment.
[0012]
Further, an eraser mounting base 4c is integrally provided at the rear end of the core case 4, the eraser 13 is fastened to the inner hole portion thereof, the cap 12 is fitted to the outer peripheral portion, and the rear end portion thereof is a knock portion. Has been made.
[0013]
[Action]
The configuration of the present invention is as described above. The chuck 3 grips the core when engaged with the first fastening ring 5, knocks the rear end of the cap 12, and the first fastening together with the chuck 3. The core moves forward until the ring advances and the first tightening ring 5 abuts the rear end of the stop ring 6 to prevent advancement. Moreover, the gripping of the lead is released by releasing the tightening of the chuck 3. The lead is gradually drawn out by repeating the above-mentioned knock forward and reverse by knock release.
[0014]
Further, when the tip of the chuck is engaged with the second fastening ring 7 in the tip provided at the front end of the shaft cylinder 1 by moving the chuck 3 forward, the core is gripped, and the core gripping state is maintained to move backward. By doing so, the core which protruded from the front-end | tip of the front-end | tip pipe 2a of a front-end | tip part is accommodated. Further, immediately before the tip of the chuck 3 is engaged with the second fastening ring 7, the front end of the slide cylinder 9 that has advanced with the core case 4 comes into contact with the rear stage portion 1 b provided on the shaft cylinder 1 to prevent the advancement. Since the damper spring 10 is compressed (damper is actuated) and the knocking force is rapidly increased, the difference between the knocking action when the lead is extended and the knocking action when the lead is accommodated can be easily grasped. (By the way, the knocking force when the lead is extended is approximately 4.41N, and the knocking force for accommodating the lead is approximately 10.79N.)
[0015]
【The invention's effect】
The configuration and operation of the present invention are as described above, and it is easy to distinguish between a small stroke and a large stroke, and this type of conventional mechanical pencil knocks out the stroke difference of the chuck for feeding the lead and receiving the lead. Since this is done by adjusting and adjusting the part, the problem of unintentionally extending the lead is solved.
Further, the stroke difference for feeding the lead and receiving the lead can be achieved by clarifying the difference in the knocking force with a simple structure, and a mechanical pencil with good operability can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a longitudinal half sectional view of a mechanical pencil according to an embodiment of the present invention.
FIG. 2 is a half sectional view showing a lead case of the mechanical pencil.
FIG. 3 is a half sectional view of a slide cylinder which is the gist of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft cylinder 1a Front part 1b Rear part 2 Tip part 2a Tip pipe part 2b Holding chuck 3 Chuck 4 Core case 4a Step part 4b Projection part 4c Eraser mounting base 5 First fastening ring 6 Stop ring 7 Second fastening ring 8 Spring 9 Slide cylinder 9a Inner step 9b Slit portion 9c Taper portion 9d Step portion 9e Hole portion 10 Damper spring 11 Grip 12 Cap 13 Eraser

Claims (1)

The chuck connected to the core case in the shaft cylinder is urged toward the retracting side by a spring, and when the chuck is engaged with the first tightening ring, the core is gripped, and the chuck is moved forward to be detached from the tightening ring. Sometimes the lead is released, the chuck is advanced further, and the lead is gripped when the tip of the chuck is engaged with the second fastening ring in the tip provided at the front end of the shaft cylinder, and the lead can be retracted in the state of gripping the lead. In the mechanical pencil configured as follows, the knock portion provided at the rear end of the lead case is moved forward and backward with respect to the shaft cylinder, and the chuck is disengaged from the first tightening ring to be released from the front end of the tip portion. The core is extended and immediately before the tip of the chuck engages with the second tightening ring, the damper is actuated to rapidly increase the knocking force, and the tip of the chuck is engaged with and disengaged from the second tightening ring. Protruding Were to be accommodated in the snout portion, and the projection provided on the front outer circumference of the lead case, a spring for a damper is resiliently between the inner step of the slide cylinder is fitted from the front of the lead case In this state, the rear end of the slide cylinder is locked to the protrusion of the lead case, and when the front end of the slide cylinder comes into contact with the step provided on the shaft cylinder, only the lead case moves forward. The mechanical pencil is constructed so that the damper operates .

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