JPS6021275Y2 - Shape pencil - Google Patents

Description

[Detailed description of the invention] This invention relates to a mechanical pencil in which the lead is drawn out by pressing the tip of the lead with a force greater than the writing pressure.

Conventional mechanical pencils available on the market include rotary mechanical pencils that feed out the lead by rotating the shaft, and knock-type mechanical pencils that move the chuck forward and feed out the lead by knocking on a knob protruding from the rear end of the shaft. However, with rotary mechanical pencils, you have to turn the shaft with both hands to feed out the lead, and with knock-type mechanical pencils, you have to change hands and knock on the knob to draw out the lead, which is very inconvenient. It was efficiency.

An application similar to this invention is JP-A-52-8681.
9 and JP-A-53-145734, but JP-A-52-8681 is provided with an enlargement mechanism that allows the sliding tube and the lead holder to retreat beyond the retraction distance of the lead. JP-A-53-145734 discloses a delay mechanism in which the core sliding tube and the clamping mechanism move back by the same distance, and only one of the sliding tube and the clamping mechanism moves forward first and returns to its original state. This is completely different from the structure of the present invention in which a cam is provided to retract the lead holding mechanism consisting of the chuck, fastener, and connector more than the retraction of the lead.

This device eliminates the above-mentioned conventional drawbacks. When the tip of the waist core is pressed and retreated, the core holder moves the core forward with slight frictional resistance in the middle piece, but holds it backward with strong force. By providing this, the middle piece fixed to the lead protection tube moves back together with the lead, and the cam that rotates when the middle piece abuts moves the lead holding mechanism back more than the distance that the lead retreated, so that the lead remains constant. The purpose is to provide a mechanical pencil that is dispensed in small amounts.

The structure of this invention will be explained based on the drawings. As shown in FIGS. 1 and 2, a rear ball 2 is rotatably fitted into a ball holding hole provided in a head 1A of a chuck 1.

A chuck spring 4 with a very weak elastic force is provided between the rear outer stage 1B of the chuck 1 and the rear inner stage 3A of the fastener 3, and the rear ball 2 is brought into contact with the tapered surface 3B of the fastener 3. When the chuck 1 is closed, the core 5 moves forward in the chuck 1 with slight frictional resistance, but is strongly held in the rear by a wedge force.

The outer flange 3C of the fastener 3 is loosely fitted into the groove 6A of the connector 6, and the front end 6B of the connector 6 has an open hole 6C with a larger diameter than the core 5 in the center.
The core holding mechanism is constructed by the following.

A front portion 7A of the core tank 7, which is vertically divided into several parts and configured to have elasticity, is fitted onto the cylindrical portion 3D of the fastener 3.
The frictional resistance between the core tank 7 and the fastener 3 is the chuck spring 4.
The elastic force is stronger than that of the

Furthermore, an outer spring 8 is constructed between the inner part 6D of the connector 6 and the front end of the core tank 7, and the elastic force of the outer spring 8 is constructed to be stronger than the frictional resistance between the core tank 7 and the fastener 3. Therefore, the outer flange 7B of the core tank 7 is in contact with the rear inner flange 6E of the connector 6.

At this time, the rear part of the chuck 1 projects slightly rearward from the fastener 3 and is provided with an appropriate clearance from the interior 7C of the core tank 7.

A writing pressure spring 10 having an arbitrarily determined elastic force is provided between the rear end of the connector 6 and the interior 9A of the shaft 9,
The outer leg 6F of the connector 6 has a cap 11 screwed onto the front part of the shaft 9.
It is in contact with the rear end 11A of.

On the other hand, a middle piece 13 is fixed to the rear part of the core protection tube 12, and a lead holder 14 divided into several parts is loosely fitted into the middle piece 13.

Furthermore, a core holder is provided between the middle piece 13 and the core holder 14.
A spring 15 is provided, and the front ball 16 provided in the ball holding portion of the core holder 14 comes into contact with the tapered portion 13A of the middle piece 13 so as to gradually close toward the rear in the axial direction. The lead 5 is configured to move forward within the lead holder 14 with slight frictional resistance, but to be strongly held in the rear by a wedge force.

The core protection tube 12 and the middle piece 13 are slidably loosely fitted into the base 11, and a base spring 18 is provided between the outer flange 13B of the middle piece 13 and the fixed tube 17 fixed to the base 11. The core protection tube 12 is configured to appropriately protrude from the tip 11B of the base 11.

The pin 17B provided on the rear piece 17A of the fixed tube 17 has a locking hole 19B in the bifurcated foot portion 19A of the cam 19.
The cam 19 is rotatably fitted, and the tip of the cam 19 is provided with a pushing part 19C that protrudes rearward, and the lead holder 14, which strongly holds the lead 5 rearward by a wedge force, is retracted together with the lead 5. , the middle piece 13 containing the lead holder 14 and the lead protection tube 12 fixed to the middle piece 13 are moved back.

At the same time, the connector 6, the chuck 1, and the fastener 6, which are members of the core holding mechanism that strongly holds the core, move backward together with the core 5.

When these move back a certain distance, middle piece 13 and cam 1
9 makes contact and rotates the cam 19, and furthermore, the push portion 19C of the cam 19 and the front end 6B of the connector 6 make contact.

When the core 5 is further pressed, the cam 19 is pushed by the middle piece 13 fixed to the core protection tube 12, and the pin 17 of the fixed tube 17 is pushed.
The cam 19 is tilted rearward using B as a fulcrum, and the cam 19 pushes the connecting tool 6, and the lead holding mechanism consisting of the characto fastener 3 and the connecting tool 6 and the lead tank 7 are 1. The chuck 1 slides on the surface of the core 5 and retreats beyond the core 5 and the core protection tube 12.

That is, with respect to the moving distance L□ of the lead 5 and the lead protection tube 12, the lead holding mechanism moves back by a distance h, resulting in the state shown in FIG.

Next, when the pressure on the lead 5 is released, the lead 5, lead protection tube 12, charm fastener 3, connector 6, and lead tank 7 move forward due to the elastic force of the pen pressure spring 10 and the base spring 18. The core protection tube 12 moves forward by a distance of L, whereas the charm fastener 3, coupling tool 6, and core tank 7 move forward by a distance of L2.

Moreover, at this time, since the core 5 is strongly held by the wedge force of the chuck 1, it moves forward together with the chuck 1 -L2
It is extended from the core protection tube 12 by a distance of L1=L3 and returns to the state shown in FIG.

When one lead 5 becomes short due to repeated writing and an attempt is made to use the next lead 5, the fastener 3 and chuck 1 move forward together by pressing the lead tank 7, and the fastener 3 is brought into contact with the front end 6B of the connector 6.

When the core tank 7 is further advanced, the internal structure 7 of the core tank 7
C contacts the rear end IC of the chuck 1, and the chuck 1 expands while moving forward.

Therefore, the lead 5 falls to the rear end of the lead holder 14, resulting in the state shown in FIG. 4.

Next, when the pressure on the core tank 7 is released, the frictional resistance between the core tank 7 and the fastener 3 is stronger than the elastic force of the chuck spring 4, so the chuck 1 retreats in the expanded state.

When the fastener 3 comes into contact with the inner part 6D of the connector 6, the rear end IC of the chuck 1 and the inner part 7C of the core tank 7 are separated.
After being loosely fitted into the head IA of the chuck 1, the ball 2 is attached to the fastener 3.
The outer flange 7B of the core tank 7 abuts against the rear end inner flange 6E of the connector 6.

When the lead tank 7 is pressed again, the lead 5 is drawn out by the moving distance of the fastener 3, and by pressing the lead tank 7 several times, the lead 5 protrudes from the tip of the lead protection tube 12.

FIG. 5 shows another embodiment of this invention, in which a rubber front core holder 20 is built in front of the core holder 114 provided in the middle piece 113, and the front end of the fastener 103 is An expansion pipe 21 having an inner diameter slightly larger than the core diameter is fixed to 103E, and the expansion pipe 21 is configured to protrude forward from the opening hole 106C of the connector 106.

By configuring the mechanical pencil as shown in FIG. 5, when the lead tank 107 is knocked and the chuck 101 is expanded, the lead holder 114 is also pushed out and expanded by the expansion pipe 21, and the next lead is opened. 105 is the front core holder-20
It falls to the rear end and the next core 105 is reliably fed out.

In addition, if you create a suitable gap between the lead protection tube and the cam and write without the lead protruding beyond the lead protection tube, it can easily be used as an automatic mechanical pencil that feeds out the amount that the lead wears out. be.

In the present invention as explained above, a core holder divided into several parts is loosely fitted into the middle piece, and the lead holder is brought into contact with a part of the taper of the middle piece by the lead holder spring, so that the lead holder does not move forward slightly. It is constructed so that it moves with a strong frictional resistance, but is held in the rear with a strong force, and a cam is rotatably attached to a fixed tube fixed to the base, and by pressing the core, the middle piece is moved backward, and the The center piece rotates the cam to move the lead holding mechanism back more than the lead retreats, producing an excellent effect in which the lead is fed out a fixed amount each time the tip of the lead is pressed.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view showing the mechanical pencil of this invention.
Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, Fig. 3 is a longitudinal sectional view showing the tip of the mechanical pencil of this invention in a pressed state, and Fig. 4 is a lead of the mechanical pencil of this invention. A vertical cross-sectional view showing the tank in a pressed state, and FIG. 5 is a vertical cross-sectional view of main parts showing another embodiment of this invention. 1・101... Chuck, IA... Head of chuck 1, IB... Rear outer stage of chuck 1, IC...... Back of chuck 1 End, 2...
... Rear ball, 3.103... Fastener, 3A...
...Rear inner stage of fastener 3, 3B...Tapered surface of fastener 3, 3C...Outer flange of fastener 3, 3D...
...Cylindrical part of fastener 3, 103E... Fastener 1
Front end of 03, 4...Chuck spring, 5.
105...Core, 6, 106...Connector, 6A...Concave groove of connector 6, 6B...
Front end of connector 6, 6C/106C...Coupler 6
・Opening hole 106, 6D... Internal installation of connector 6,
6E... Rear inner flange of connector 6, 6F...
・External installation of connector 6, 7・107...core tank,
7A...Front part of core tank 7, 7B...
Outer flange of core tank 7, 7C...Inner installation of core tank 7, 8...Outer spring, 9...Shaft, 9
A... Internal installation of shaft 9, 10... Pen pressure spring, 11... Cap, 11A... Rear end of cap 11, IIB... ... Tip of base 11, 1
2...Core protection tube, 13.113...Middle piece, 13A...Taper part of middle piece 13, 13B
・・・・・・Naka piece 13 sototsuba, 14・114・・・・
- Core holder, 15... Core holder spring, 16... Front ball, 17... Fixed tube, 17A... Rear piece of fixed tube 17. , 17B...
... Pin of fixed tube 17, 18 ... Base spring, 19 ... Cam, 19A ... Leg of cam 19, 19B ... Cam 19 locking holes,
19C... Pushing part of cam 19, 20...
Front core holder-21...Expansion pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A lead holding mechanism that moves the lead forward with slight frictional resistance but holds it backward with strong force, using a chuck, fastener,
In a mechanical pencil composed of a connector and a chuck spring, a writing pressure spring is provided between a shaft to which a base is screwed to the front part and a connector loosely fitted in a slidable manner within the shaft, and the writing pressure spring is The connecting tool is brought into contact with the base, the middle piece with the waist core protection tube fixed is slidably and loosely fitted into the base, and the core holder divided into several pieces is loosely fitted into the middle piece,
Furthermore, a lead holder spring is provided between the middle piece and the lead holder, and the lead holder is brought into contact with a part of the tapered part of the middle piece that is inclined so as to gradually close as it goes rearward in the axial direction of the middle piece. It is configured so that it moves forward with little frictional resistance, but is held in the rear with strong force.
A base spring is provided between the center piece and a fixed tube fixed to the base, and a cam is rotatably attached to the fixed tube, and the center piece and cam come into contact from the rotatable connection between the fixed tube and the cam. A mechanical pencil characterized in that the distance from the connecting part of the fixed tube and the cam to the abutting part of the cam and the connecting tool is longer than the distance to the connecting part. 2. A pin is provided on the rear piece of the fixed tube that protrudes rearward, and the locking hole of the bifurcated leg of the cam is rotatably fitted into the pin, and a push part that protrudes rearward is attached to the tip of the cam. A mechanical pencil according to claim 1 of the utility model registration claim, characterized in that the mechanical pencil is provided with: