JPS6345332Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field of industrial application) The present invention relates to a ballpoint pen used in an automatic drawing machine.

(Prior art) Ballpoint pens that perform recording by rolling a ball on a recording paper and transferring ink adhering to the surface of the ball to the recording paper generally have a ball support part, as seen in Japanese Utility Model Publication No. 7499/1983. The edge of the ball is caulked inward to prevent the ball from falling off.

However, since this type of ballpoint pen is mainly designed for writing, it is difficult to hold the pen against the paper.
The exposed surface of the ball is at the center, as shown in Figure 2a, because the edge of the support part is kept at a certain height from the paper surface so that it does not come into contact with the paper surface even when it is tilted around 60 degrees. The opening angle θ′ is over 100°. Therefore, when using this type of ballpoint pen as a recording pen for an automatic drafting machine,
As shown in Figure b, not only is it not possible to provide the ink supply part b near the exposed surface of the ball a, but also a large ink consumption surface c is created at the rear of the rolling direction of the ball a. When the recording direction is abruptly reversed, such as when writing an IC pattern, there is an inconvenience that a line drawing defect called "line break" occurs at the beginning of writing.

(Purpose) The present invention was made in view of the above-mentioned problems, and its purpose is to provide an improved ballpoint pen for automatic drafting machines that causes as few line drawing defects as possible.

(Means for Achieving the Object) That is, the present invention is a ballpoint pen for an automatic drafting machine to achieve the above object, which includes a ball catch and a ball catch at the tip of the shaft main body which is held almost perpendicularly to the surface of the recording paper. A cylindrical part for holding the ball is formed, and at the tip of the cylindrical part, a ball holding edge is formed at a nearly right angle inward so that the exposed surface of the ball is within 80 degrees from the center. A lower ink reservoir is a curved annular corner having a substantially triangular cross section formed between the cylindrical portion and the ball-containing edge.

(Example) The details of the present invention will be explained below based on the illustrated example.

FIG. 1 shows an embodiment of the present invention, in which a bearing body 1, which is held perpendicularly to the recording paper surface S by a clamp member (not shown), has a ball 2 rotatably held at its tip. The holding portion 3 is formed to communicate with the ink chamber 4.

This ball holding part 3 is composed of a catch seat 5 for receiving the ball 2, and a cylindrical part 6 extending from the catch seat 5 toward the tip. By bending the ball in a direction substantially perpendicular to the ball, the ball enclosing edges 7, 7 are formed so that the ball 2 held inside is exposed to the lower surface within a range where the opening angle θ of the center is within 80°. In addition, the annular corner with a triangular cross section formed between the cylindrical part 6 and the catch seat 5 is configured as an upper ink reservoir 8, and the annular corner with a triangular cross section formed between the cylindrical part 6 and the ball enclosing edge 7 is configured as follows. Place the annular corner of the shape into the lower ink pool 9
It is configured as 1, 9r.

Therefore, when the ballpoint pen configured as described above is moved in the direction of the arrow in the figure, the ball 2 carrying ink on its surface exposes as little surface as possible from the ball-wrapping edge 7 and moves toward the recording paper. s, records are written there using ink, and then enters the ball holding section 3 again.

On the other hand, as the ball 2 rotates counterclockwise at this time, the ink on the surface of the ball 2 flows from the ink chamber 4 to the upper ink pool 8 on the upper side in the moving direction.
In addition to being supplied to the lower ink reservoir 9L through
The ink on the surface of the ball 2 that has been scraped off by the tip of the ball-wrapping edge 7 is collected in this lower ink reservoir 9l, so that the surplus of the ink collected in this area is formed into an annular shape having a triangular cross section. The ink flows in an annular manner through the large lower ink reservoir 9l to the lower ink reservoir 9r on the downstream side in the direction of movement, and spreads equally around the entire circumference.

Therefore, the lower ink reservoir 9r on the lower side in the movement direction immediately contacts the surface of the ball 2 that has consumed ink, replenishes it with ink supplied from the upper side, and prepares for the next recording. Even when the direction of recording is suddenly reversed, in addition to the small ink consumption surface c of the ball 2 surface (Fig. 1b), the next recording with ink can be carried out without causing line breakage on the recording paper s. is carried out without any problems.

(Effects) As described above, according to the present invention, by bending the tip of the cylindrical part that holds the ball inward at a substantially right angle, a substantially triangular cross section is formed at the annular corner between the two. Since a large lower ink pool is formed, as the ball rotates, the ink supplied to the upper side in the direction of pen movement is distributed around the entire circumference of the lower ink pool closest to the exposed part of the ball. Ink can be replenished, and inconveniences such as line breakage can be suppressed as much as possible even when the recording direction suddenly changes. At the same time, the ball retaining edge at the tip of the cylindrical part allows the exposed surface of the ball to be By making it as small as possible, the ink consuming surface of the ball surface can be reduced as much as possible, and line breakage that occurs when the recording direction is changed can be eliminated.

[Brief explanation of drawings]

Figures 1a and b are cross-sectional views showing the main parts of a ballpoint pen, which is an embodiment of the present invention, and the exposed surface of the ball. Figures 2a and b are cross-sectional views of a general ballpoint pen and the ball. This shows the exposed surface. DESCRIPTION OF SYMBOLS 1... bearing shaft body, 2... ball, 6... cylindrical part, 7... ball surrounding edge, 8... upper ink reservoir, 9... lower ink reservoir.

Claims (1)

[Scope of utility model registration request] A ball catch and a cylindrical part for holding the ball are formed at the tip of the bearing shaft that is held almost perpendicular to the recording paper surface, and the exposed surface of the ball is located at the tip of the cylindrical part from the center. The ball holding edge is bent inward at a substantially right angle so that the opening angle is within 80°, and the cross section formed between the cylindrical part and the ball holding edge is approximately triangular. A ballpoint pen for automatic drawing machines, characterized in that the annular corner serves as a lower ink reservoir.