JPH0436310Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention allows the lead to be automatically fed out by the length worn out by drawing. To provide a drawing head for a drafting machine that automatically follows a spare lead when the lead being used for drawing is worn out and can always draw with a constant writing pressure.

[Conventional technology]

Conventionally, as a drawing head for a drafting machine, in which the lead is automatically fed out by the distance worn by drawing, and the lead is automatically followed by a spare lead,
No. 59-93396, which uses a compression spring (the invention's invention) to transmit pressure between the clamping body that holds the core (the invention's chuck) and the core guide tube (the invention's core guide). When the spring at It was closed by rolling elements (balls in the present invention) that rotated while sliding along the tapered surface in the present invention, and held the core immovable.

[Problem that the invention attempts to solve]

The drawing head of a drafting machine can be a felt-tip pen or
There are ballpoint pen bodies, sharp pencil bodies, etc., and since these can be exchanged at will for drawing, the normal writing pressure is around 60g, and the maximum writing pressure that uses a sharp pencil body is 150g to 200g. Ta. If the writing pressure is increased more than that, the tip of the felt-tip pen will be damaged or the structure will become complicated. Therefore, in the above-mentioned Japanese Patent Application Laid-open No. 59-93396, (1) the rolling elements rotate and retreat while sliding, so the resistance generated on the rolling elements is large and the compression spring becomes strong. Therefore, when the lead is pressed against the paper surface during drawing, the force generated by the pressure spring is less than the elastic force of the compression spring, resulting in a thin and unclear handwriting.

(2) Since the amount of axial rearward movement of the clamping body is distributed over both the sliding distance of the rolling elements and the distance in which the clamping body closes, the clamping body moves from the time the core guide tube is pressed against the surface of the paper. The retraction distance of the lead guide tube until it closes and holds the lead is large, and the loss of time when writing by moving the drawing head of the drafting machine up and down becomes very large.

[Means for solving problems]

The present invention solves the above problems, and includes:
The first hole 1A located in the front part of the shaft cylinder 1, the contents of which will be explained below using FIG. 1 corresponding to the embodiment.
The outer flange 2A of the core guide tool 2 is built in so as to be slidable in the axial direction, and the inner tube part 2C of the core guide tool 2 has a built-in core holder 4 that holds the core 3 with an appropriate force.
Furthermore, the outer flange 5A of the fastener 5 is inserted into the second hole 1B of the shaft cylinder 1.
is built in so as to be freely slidable in the axial direction, and a writing pressure spring 6 having an elastic force corresponding to the writing pressure is tensioned between the rear end of the outer flange 5A of the fastener 5 and the inner stage 1C of the shaft tube 1. The outer flange 5A of the fastener 5 is in contact with the inner flange 1D of the shaft cylinder 1. Moreover, the core guide tool 2 and the spring receiver 7
A spring 8 is provided between the spring receiver 7 and the tapered surface 5B of the fastener 5, which narrows toward the rear in the axial direction, and a ball 10 is provided with an appropriate gap. The ball 1
0 is rotatably attached to a concave portion 9A formed on the head of the chuck 9, and the chuck 9 normally expands due to its own elasticity so that the core 3 can freely pass through the chuck 9. Furthermore, the barrel 1 is attached to a pen holder 11, and the head body 13, which moves the pen holder 11 up and down with respect to the paper surface 12 using an electromagnet, is configured to move parallel to the paper surface 12 while being slightly away from it.

[Effect]

From the state shown in Figure 1, move the pen holder 11 to the paper surface 12.
The tip of the core guide tool 2 is brought into contact with the surface 12 of the paper. Then, the rear end 7B of the spring receiver 7 comes into contact with the ball 10 via the spring 8. The ball 10 retreats along the tapered surface 5B of the fastener 5, and the chuck 9 with the ball 10 positioned in the concave portion 9A also retreats, but at this time the ball 10
The chuck 9 is closed by the wedge action between the chuck 9 and the tapered surface 5B of the fastener 5, and the chuck 9 is strongly held against the rear in the axial direction. Therefore, if the head main body 13 is moved parallel to the paper surface 12 in this state, writing is performed. Then, place the pen holder 11 on the paper surface 12.
If it is moved further upward, the state shown in FIG. 1 is restored and writing is completed. At this time, if the lead 3 becomes short due to wear, a spare lead 3 falls from the rear of the chuck 9 and comes into contact with the rear end of the shortened lead 3, and the next lead 3 automatically follows. be done.

〔Example〕

FIG. 1 shows an embodiment of this invention, in which an outer flange 2A of a core guide 2 is housed in a first hole 1A located at the front of a shaft cylinder 1 so as to be slidable in the axial direction. An inner tube portion 2C extending axially rearward from the front inner surface 2B of the guide tool 2 has a built-in lead holder 4 that holds the lead 3 with an appropriate force. Furthermore, the first hole 1 of the shaft cylinder 1
The outer flange 5A of the fastener 5 is loosely fitted into the second hole 1B located rearward from A, and a pressure corresponding to the writing pressure is applied between the rear end of the outer flange 5A of the fastener 5 and the inner stage 1C of the barrel 1. A pen pressure spring 6 having an elastic force is stretched, and the outer flange 5A of the fastener 5 is brought into contact with the inner flange 1D of the barrel 1. The inner surface of this fastener 5 is formed with a tapered surface 5B that becomes narrower toward the rear in the axial direction. Moreover, the front inner surface 2B of the core guide 2 and the spring receiver 7
A spring 8 is stretched between the inner collar 7A of the spring receiver 7 and the inner tube part 2C of the core guide tool 2.
It is in contact with the outer stage 2D provided in the. A ball 10 is loosely fitted between the rear end 7B of the spring receiver 7 and the tapered surface 5B of the fastener 5, with a gap allowing the chuck 9 to expand. The chuck 9 is rotatably attached to the provided concave portion 9A, so that the chuck 9 expands by its own elasticity to release the core 3, and the rear end 9B of the chuck 9 is inserted into the small diameter hole 1E of the shaft tube 1. is slidably inserted in the axial direction. A lead storage chamber 1F for storing a spare lead 3 is provided behind the small diameter hole 1E of the shaft tube 1, and a lead 3 is stored in the small diameter hole 1E at the front end of the lead storage chamber 1F.
A funnel-shaped portion 1G is configured to guide the. The outer flange 1H of the barrel 1 is detachably attached to a holding section 11A of a pen holder 11, and the pen holder 11 is attached to the head body 13 so as to be movable up and down relative to the paper surface 12 by an electromagnet.

In order to draw with the drawing head of the drawing machine constructed in this way, the pen holder 11 is lowered toward the paper surface 12 from the state shown in FIG. 1, and the lead guide tool 2 is brought into contact with the paper surface 12. Then, the pressing force of the core guide tool 2 received by the paper surface 12 is transmitted to the spring receiver 7 via the spring 8, and the rear end 7B of the spring receiver 7 comes into contact with the ball 10. Therefore, the ball 10 slides axially rearward along the tapered surface 5B of the fastener 5, and the chuck 9 in which the ball 10 is provided in the recess 9A is closed. Therefore ball 1
0 and the tapered surface 5B of the fastener 5, the chuck 9 holds the lead 3 with a strong force toward the rear in the axial direction.
When the core 3 is lowered toward the paper surface 12, it cannot move forward in the axial direction (the direction in which it descends toward the paper surface 12), and the core 3 is held firmly against the rear in the axial direction. The chuck 9 also cannot move forward in the axial direction and is stopped. Therefore, the paper surface 12, which receives the ball 10 provided in the concave portion 9A of the chuck 9 by the tapered surface 5B, cannot move forward in the axial direction, and only the barrel 1 moves forward in the axial direction while compressing the pen pressure spring 6. Move to
The state shown in FIG. 2 is reached. If the head body 13 is moved parallel to the paper surface 12 in this state, any drawing can be performed.
is compressed, and the fastener 5, chuck 9, and lead 3 move forward in the axial direction. When drawing is completed, the pen holder 11 rises relative to the paper surface 12, the pen pressure spring 6 expands, and the fastener 5 moves forward.・Chick 9・Core 3
Both the core guide tool 2 move forward in the axial direction, and the outer flange 5A of the fastener 5 comes into contact with the inner flange 1D of the shaft cylinder 1. After that, the spring 8 expands, and the core guide tool 2
is further moved forward in the axial direction, but the lead holder 4
Since the wedge action between the ball 10 and the tapered surface 5B of the fastener 5 is released from the axially forward direction, the core 3 held by the core 3 slides inside the chuck 9 and moves forward in the axial direction together with the core guide tool 2. When the outer stage 2D provided on the inner tube portion 2C of the core guide 2 moves and comes into contact with the inner flange 7A of the spring receiver 7, a gap is created between the rear end 7B of the spring receiver 7 and the ball 10. The resulting chuck 9 expands by its own elasticity and returns to the upward position shown in FIG. 1, and the core 3 is automatically fed out by the amount of wear. At this time, when the lead 3 becomes short due to wear and the rear end of the lead 3 is located axially forward of the chuck 9, the spare lead 3 in the lead storage chamber 1F falls due to its own weight and is inserted into the chuck 9. It comes into contact with the rear end of the shortened lead 3, so even if the lead 3 is shortened, the next lead 3 is held by the chuck 9, so drawing is done in the same way as when using one lead 3. be able to.

FIG. 3 shows another embodiment of this invention, in which a naturally stretched spring 8 is provided between the front inner surface 102B of the core guide 102 and the outer stage 107C of the spring receiver 107. Uke 107
The chuck 9 has an expandable gap between the rear end 107B and the tapered surface 5B of the fastener 5, and a ball 10 is loosely fitted therein.

4 and 5 show another embodiment of this invention, in which a thin tube portion 202E is protruded from the tip of the core guide 202, and the head body 13 is
A stopper 14 that can come into contact with the front outer stage 202F of the lead guide 202 is provided at the front of the stopper 14 and the front of the lead guide 202 when the pen holder 11 is raised from the paper surface 12 as shown in FIG. Although it is separated from the outer stage 202F, the pen holder 1
1 is lowered relative to the paper surface 12, the front outer stage 202F of the core guide tool 202 comes into contact with the stopper 14 as shown in FIG.
The tip 202G of No. 2 is slightly away from the paper surface 12. Therefore, the paper surface 12 is not torn by the core guide tool 202, and the paper surface 12 and the core guide tool 20 are not damaged.
Since the distance between the lead 2 and the tip 202G is extremely small, there is no fear that the lead 3 will be damaged.

[Effect of idea]

As explained above, the present invention provides a spring between the core guide tool and the spring receiver, and a ball with a gap between the spring receiver and the tapered surface of the fastener that allows the chuck to expand. . Another feature is that a pen pressure spring is stretched between the fastener and the barrel.

This allows you to always draw with a constant writing pressure, and the elastic force of the writing pressure spring that is canceled out by the spring is reduced, allowing you to draw with strong writing pressure, resulting in clear handwriting.
Furthermore, it becomes possible to press the ball against the tapered surface of the fastener by reversing the core guide by a slight force and by a very short distance, thereby achieving the effect of reliably holding the core. Furthermore, compared to the drawing head of a drawing machine in which a conventional spare lead automatically follows, there is less time loss in up and down movements and the drawing time can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the drawing head of the drawing machine of this invention, Fig. 2 is a longitudinal sectional view showing the writing state of the drawing head of the drawing machine of Fig. 1, and Figs. 3 and 4 are FIG. 5 is a longitudinal sectional view showing another embodiment of the drawing head of the drawing machine of this invention, and FIG. 5 is a longitudinal sectional view showing the writing state of the drawing head of the drawing machine of FIG. 1... shaft cylinder, 1A... first hole of shaft cylinder 1, 1B...
...Second hole of barrel 1, 1C...Inner stage of barrel 1, 1D
...Inner flange of shaft cylinder 1, 1E...Small diameter hole of shaft cylinder 1, 1
F... Core storage chamber of the barrel 1, 1G... Funnel-shaped part of the barrel 1, 1H... Outer flange of the barrel 1, 2, 102, 2
02... Core guide tool, 2A... Outer flange of core guide tool 2,
2B, 102B...Front inner surface of the core guide tool 2, 102, 2C...Inner tube part of the core guide tool 2, 2D...Outer stage of the core guide tool 2, 202E...Thin tube part of the core guide tool 202, 202F...Front outer stage of the core guide tool 202,
200G... Tip of the core guide tool 202, 3... Core,
4... Core holder, 5... Fastener, 5A... Fastener 5
outer flange, 5B...tapered surface of fastener 5, 6...pen pressure spring, 7,107...spring holder, 7
A...Inner flange of spring receiver 7, 7B, 107B...
...Spring receiver 7, rear end of 107, 107C...
Outer stage of spring receiver 107, 8...spring,
9...chuck, 9A...recessed part of chuck 9,
9B... Rear part of chuck 9, 10... Ball, 1
1...Pen holder, 11A...Pen holder 1
1 holding portion, 12...paper surface, 13...head body, 14...stopper.

Claims (1)

[Scope of utility model registration request] In the drawing head, which performs drawing by moving parallel to the paper surface and descending toward the paper surface,
A shaft cylinder housing a plurality of cores in the rear part, a core guide attached to the front part of the shaft cylinder so as to be slidable in the axial direction,
A lead holder built into the lead guide to hold the lead with an appropriate force, a fastener built into the barrel and biased axially forward by a pen pressure spring, and a clamp that slides axially inside the barrel. Equipped with a freely built-in spring holder, a spring installed between the lead guide and the spring holder and with a weaker elastic force than the writing pressure spring, and a ball located in the recessed part of the chuck, the chuck expands. By providing a ball between the spring holder and the tapered surface of the fastener with a possible gap, the drawing head of the drawing machine rises and the core guide is fixed at the paper surface or at a constant height above the paper surface. When separated from the stopper, the chuck expands and the lead can fall into the chuck under its own weight.
In addition, when the drawing head of the drawing machine is lowered and the core guide is in contact with the paper surface or the stopper and slightly retreated, the ball is pressed against the tapered surface of the fastener by the elastic force of the spring and is moved inward. Also, a drawing head for a drafting machine, characterized in that the chuck is pressed closed by a ball to strongly hold the lead.