JPH045349Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention allows the lead to be automatically fed out by the length of the lead that has been worn out by writing, and if the lead being used for writing wears out, a spare lead is automatically provided. This invention relates to a self-feeding mechanical pencil that follows.

[Conventional technology]

Conventionally, there is Japanese Patent Application Laid-Open No. 59-93397, which is an automatic mechanical pencil in which the lead is automatically fed out by the length worn out by writing, and the lead is automatically followed by a spare lead. A compression spring (spring in this invention) for pressure transmission is formed between the clamping body (chuck in this invention) that holds the lead and the lead guide tube (lead guide pipe in this invention), and when starting to write, ,
The axial rearward force of the core guide tube that is in contact with the paper surface is transmitted to the clamping body through the compression spring, and the clamping body rotates while sliding along a sliding conical surface (tapered surface in the present invention). It was closed by rolling elements (balls in the present invention) that held the core immovable.

[Problem that the invention attempts to solve]

Therefore, in the conventional system, (1) the rolling elements rotate and retreat while sliding;
The resistance generated in the rolling elements increases, and therefore the compression spring must be strengthened, so the force of the core guide tube that comes into contact with the paper surface when writing is strong, resulting in poor writing quality and the risk of damaging the paper. It was hot.

(2) Since the amount of rearward movement of the clamping body in the axial direction is distributed over both the sliding distance of the rolling elements and the distance of the rolling elements closing, the clamping body moves from the time the core guide tube is pressed against the paper surface. The retraction distance of the lead guide tube until it is closed to hold the lead is large, making it extremely difficult to write.

[Means for solving problems]

The present invention solves the above problems, and includes:
To explain using FIG. 1 corresponding to the embodiment, a cap 2 is screwed onto a shaft tube 1, and a core 4 is appropriately fitted into a core guide pipe 3 that is loosely fitted into the cap 2 so as to be slidable in the axial direction. It has a built-in core holder 5 that is held with the force of. A spring 7 is provided between the rear end 3A of the core guide pipe 3 and the inner stage 6A of the spring receiver 6, and the outer stage 3B of the core guide pipe 3 is connected to the front end inner flange 6 of the spring receiver 6.
It comes into contact with B. A ball 10, which is rotatably attached to a concave portion 9B provided in a head portion 9A of the chuck 9, is positioned with a slight gap between the spring receiver 6 and the tapered surface 1A of the shaft cylinder 1. Normally, the chuck 9 expands due to its own elasticity so that the core 4 can freely pass through the chuck 9.

[Effect]

Next, the operation of the present invention will be explained. When writing is performed from the state shown in FIG. 1, the lead guide pipe 3 is pushed back by the paper surface 14 and the spring receiver 6
Touches 0. Then, the ball 10 retreats along the tapered surface 1A of the shaft tube 1, and the chuck 9, which has positioned the ball 10 in the concave portion 9B of the head 9A, also retreats, but at this time, the ball 10 and the tapered surface of the shaft tube 1 The chuck 9 is closed by the wedge action with the chuck 1A, and the core 4 is strongly held against the rear in the axial direction, resulting in the state shown in FIG. If writing is performed in this state, the lead guide pipe 3 will retreat as the lead 4 wears out, allowing smooth writing. When you finish writing and move the tip of the lead guide pipe 3 away from the paper surface 14, the spring 7 expands and the lead guide pipe 3 moves forward.
The lead 4 held by the lead holder 5 with an appropriate force also slides forward within the chuck 9. Then, the outer stage 3B of the core guide pipe 3 comes into contact with the front inner flange 6B of the spring receiver 6, and the ball 10 is released from the restriction between the spring receiver 6 and the tapered surface 1A of the shaft cylinder 1.
The tapered surface 1 of the shaft cylinder 1 due to the expanding force of the chuck 9
Moving axially forward along A, the chuck 9 expands to release the core 4. At this time, if the lead 4 wears out due to writing and becomes short, a spare lead 4 falls into the chuck 9 due to its own weight and automatically follows.

〔Example〕

FIG. 1 shows an embodiment of this invention, in which a base 2 is screwed onto the front part of a shaft cylinder 1, and a core guide pipe 3 is loosely fitted into the base 2 so as to be slidable in the axial direction. . The lead guide pipe 3 has a built-in lead holder 5 that holds the lead 4 with an appropriate force. Rear end 3A of core guide pipe 3 and inner stage 6A of spring receiver 6
A spring 7 is stretched between the outer stage 3B of the core guide pipe 3 and the inner flange 6 of the front end of the spring receiver 6.
It is in contact with B. Further, a stopper 8 is fixed to the rear inner surface of the cap 2 to prevent the spring receiver 6 from falling off. Rear end 6 of spring receiver 6
A ball 10 is loosely fitted between C and the tapered surface 1A of the shaft cylinder 1, which becomes narrower toward the rear in the axial direction, with a gap allowing the chuck 9 to expand. 9 is rotatably attached to a recessed portion 9B provided in the head 9A. The chuck 9 expands by its own elasticity to open the core 4, and the rear part 9C of the chuck 9 is slidably inserted in the axial direction into the small diameter hole 1B that communicates with the rear from the tapered surface 1A of the shaft tube 1. be done. Behind the small diameter hole 1B of the shaft tube 1 is a lead storage chamber 1C for storing a spare lead 4.
The front end surface 1D of the lead storage chamber 1C is configured in a funnel shape to guide the lead 4 into the narrow hole 1B.
Further, an eraser case 12, which is externally fitted onto the eraser 11, is fitted into the rear inner side 1E of the barrel 1, and the lead storage chamber 1C is closed. Rear outer 1F of shaft tube 1
A knob 13 is fitted over the eraser 11 to form a self-feeding sharp pencil.

To write with the self-feeding sharp pencil configured in this way, when the lead 4 and the lead guide pipe 3 are pressed against the paper surface 14, the lead 4 and the lead guide pipe 3 are moved back, but at this time, the lead guide pipe 3 The retreat of the spring is transmitted to the spring receiver 6 via the spring 7, and the spring receiver 6 is also moved backward. Then, the rear end 6C of the spring receiver 6 is connected to the ball 1.
0, and the ball 10 retreats along the tapered surface 1A of the shaft cylinder 1. The ball 10 is placed in the concave portion 9B.
The chuck 9 provided on the shaft is closed while retracting due to the wedge action of the ball 10 and the tapered surface 1A of the shaft tube 1, and strongly holds the core 4 against backward movement in the axial direction. When writing is performed in this state, the lead guide pipe 3 moves backward against the elastic force of the spring 7 as the lead 4 wears out, resulting in the state shown in FIG. 2. Then, finish writing and use the lead 4 and lead guide pipe 3.
When is separated from the paper surface 14, the lead guide pipe 3 is moved forward by the elastic force of the spring 7, but since the lead 4 is held by the lead holder 5 built into the lead guide pipe 3, it is pulled forward. Moreover, the core 4 has a ball 1 for forward movement in the axial direction.
0 and the tapered surface 1A of the shaft tube 1 do not work, so the core guide pipe 3 moves forward. If the elastic force of the spring 7 is set to be weaker than the holding force of the lead holder 5, the lead 4 pulled out by the lead holder 5 will be drawn out more reliably. The outer stage 3B of the core guide pipe 3 is the spring receiver 6.
When it comes into contact with the front inner flange 6B of the spring receiver 6
The rear end 6C separates from the ball 10, and the chuck 9 expands by its own elasticity while moving the ball 10 forward along the tapered surface 1A of the shaft cylinder 1, returning to the state shown in FIG. If this writing operation is repeated, the lead 4 will be shortened due to friction, and when the shortened rear end of the lead 4 is located in front of the chuck 9, the tip should be placed downward for writing in the normal state shown in Figure 1. If you point it,
The spare lead 4 falls into the chuck 9 due to its own weight and comes into contact with the shortened rear end of the lead 4. If writing is performed in this state, the chuck 9 is closed and the spare lead 4 is held, so even the shortened lead 4 can be used for writing without moving back.

FIG. 3 shows another embodiment of this invention, in which a naturally stretched spring 7 is loosely fitted between the outer flange 103C of the core guide pipe 103 and the spring receiver 106. Between the rear end 106C of the spring receiver 106 and the tapered surface 1A of the shaft cylinder 1, which narrows toward the rear in the axial direction, there is a gap through which the chuck 9 can be expanded, and the ball 10 can play. The ball 10 is inserted into the recess 9B of the head 9A.
The chuck 9, which is rotatably attached to the chuck 9, expands due to its own elasticity and releases the core 4.

In the above-mentioned embodiment, a tapered surface that acts as a wedge with the ball is provided on the shaft cylinder, but the tapered surface does not necessarily have to be provided on the shaft cylinder.
As shown in the figure, the shaft cylinder 10 is slidable in the axial direction.
A tapered surface 1 is attached to a fastener 16 built in the pen pressure spring 15 and biased forward in the axial direction.
6A, there is no problem, and in this case, when more force than necessary is applied to the lead 4 and the lead guide pipe 103, the writing pressure spring 15 is compressed and can retreat.

[Effect of idea]

As explained above, in the present invention, a spring is provided between the core guide pipe and the spring receiver, and a ball is provided between the spring receiver and the tapered surface of the shaft cylinder or a fastener built in the shaft cylinder. There are some features.

This weakens the elastic force of the spring that presses the lead guide pipe against the paper surface when writing, so the frictional resistance between the lead guide pipe and the paper surface is small and the writing quality is good, and the ball instantly moves between the ball and the tapered surface. Because of the wedge effect, the retraction distance of the lead and lead guide pipe at the beginning of writing is small, allowing for very comfortable writing.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the self-feeding sharp pencil of the present invention, Fig. 2 is a longitudinal cross-sectional view showing the writing state of Fig. 1, and Figs. 3 and 4 are other embodiments of the invention. FIG. 1,101...Shaft tube, 1A...Tapered surface of shaft tube 1, 1B...Small diameter hole of shaft tube 1, 1C...Shaft tube 1
Core storage chamber, 1D...front end surface of shaft tube 1, 1E...
Rear inner side of shaft tube 1, 1F...rear outside of shaft tube 1,
2...Base, 3,103...Core guide pipe, 3
A... Rear end of the core guide pipe 3, 3B... Outer stage of the core guide pipe 3, 103C... Outer flange of the core guide pipe 103, 4... Core, 5... Core holder,
6,106...Spring receiver, 6A...Inner stage of spring receiver 6, 6B...Front end inner flange of spring receiver 6, 6C, 106C...Spring receiver 6,106
rear end, 7...spring, 8...stopper,
9...chuck, 9A...head of chuck 9, 9
B...Concave portion of chuck 9, 9C...chuck 9
Rear part, 10...Ball, 11...Eraser, 1
2... Eraser case, 13... Knob, 14...
Paper surface, 15... Pen pressure spring, 16... Fastener,
16A...Tapered surface of fastener 16.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cap connected to a shaft tube, a core guide pipe built into the cap so as to be slidable in the axial direction, and a core guide pipe built into the core guide pipe to move the core with appropriate force. A lead holder held by a lead holder, a ball located in a recess provided in the head of the chuck, and a ball that can come into contact with the shaft cylinder or a fastener built in the shaft cylinder and moves axially rearward. Accordingly, in an automatic dispensing sharp pencil consisting of a narrowed tapered surface, a spring is provided between the lead guide pipe and a built-in spring holder that is slidable in the axial direction within the mouthpiece, and the chuck expands. A self-feeding sharp pencil characterized in that a ball is provided between the spring holder and the tapered surface with a possible clearance. (2) The spring 7 is stretched between the rear end 3A of the core guide pipe 3 and the inner stage 6A of the spring receiver 6, and the outer stage 3B of the core guide pipe 3 is applied to the front inner collar 6B of the spring receiver 6. The self-dispensing mechanical pencil according to claim 1 of the claimed utility model registration, characterized in that the pencils are in contact with each other. (3) Core guide pipe 103 and spring receiver 106
1. The automatic dispensing type sharp pencil according to claim 1, characterized in that a spring 7 which is stretched in a natural state is provided between the two.