JPH03396Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a tool that easily and beautifully draws black dots or small-diameter black circles that are often drawn on drawings of machines, bridges, buildings, etc. be.

(Prior art) Conventionally, to draw a sunspot, a pencil with a sharp tip is drawn using a Helly hand, and to draw a black circle, a small hand is drawn, or a compass or a perforated plastic plate is used. After drawing a circle, I filled in the inside of the circle.

(Problems to be Solved by the Present Invention) However, when drawing black dots freehand, each drawn dot may have shading, or the dots may become short lines, making them unsightly, and their positions may be inaccurate.
When drawing a black circle, the size and shape of the drawn small circles are irregular and unsightly, and when using a compass, etc., it is time consuming and troublesome.

(Means for Solving the Problems) The present invention is to provide a pencil with an inclined lead-feeding pencil by drilling an oblique long hole at a key point in the shaft so that it can slide freely into an outer cylinder that is shorter than the overall length of the pencil. The pencil is fitted in such a way that both the upper and lower ends thereof protrude, and a guide pin protruding inward from the outer cylinder is engaged with the slanted elongated hole to hold the outer cylinder with a spring inside the outer cylinder. The above-mentioned problem is solved by biasing the core in the direction opposite to the core.

(Function) When the tool of the present invention is held perpendicular to the surface of the paper and its outer periphery is pushed down, the lead of the built-in lock-type lead-feeding pencil presses against the surface of the paper with a constant spring pressure. Rotate.

Therefore, if the tip of the lead is made sharp, a black dot with a constant density can be accurately drawn without becoming a short line, and if the tip of the lead is made flat, a black dot with a constant density and the same diameter as the lead can be drawn. You can easily draw a beautiful black circle, and if you move the lead away from the paper surface, the tool will be ready to draw the next black circle etc. due to the bias of the spring.
It will return automatically.

Moreover, the darkness of the black dots and black circles can be freely adjusted by changing the hardness of the core or the strength of the spring, and the diameter of the black circles can be freely adjusted by changing the diameter of the core.

(Example) The drawing shows an example of the tool of the present invention, in which 1 is a known lock-type lead-feeding pencil (hereinafter simply referred to as a pencil), 2 is the shaft, 3 is the lead, and 4 is the shaft at the bottom. 2, the inner cylinder whose upper part protrudes upward to the state shown in the drawing by the urging of a compression spring (not shown) installed inside the shaft part 2; 5 is its cap; when the cap 5 is pressed; As a result, the core 3 is fed out.

A pair of oblique elongated holes 6 are bored at key points of the shaft portion 2, and are slanted downward to the left and are symmetrical with respect to each other.

This pencil 1 is slidably fitted from below into an outer cylinder 7 which is a downward facing bottomed cylinder, with the lower part protruding from the outer cylinder 7 and the inner cylinder 4 passing through the bottom of the outer cylinder 7. .

Each of the inclined elongated holes 6 of the pencil 1 is engaged with the inner ends of guide pins 8 which protrude in the centripetal direction from both ends of the lower part of the outer cylinder 7 in the diametrical direction.

A coiled compression spring 9 surrounding the inner tube 4 is wound between the shaft portion 2 of the pencil 1 and the bottom of the outer tube 7.
As shown in the figure, the outer cylinder 7 is normally located at the upper limit where the guide pin 8 comes into contact with the upper end of the oblique elongated hole 6 due to the bias of the spring 9.

As shown in FIG. 2, the tool of the present invention having the above-mentioned structure is held at right angles to the paper 10, and the tip of the sharpened core 3 is lightly brought into contact with a predetermined location on the paper 10, and then the spring 9 Push down the outer cylinder 7 against the force.

Then, the pencil 1, whose inclined elongated hole 6 engages with the descending guide pin 8, rotates until the guide pin 8 reaches the lower end of the inclined elongated hole 6, so that the lead 3, under the pressure of the spring 9, Rotating while being in pressure contact with the paper 10,
Draw a sunspot.

Furthermore, when the tip of the lead 3 is made flat, a black dot with the same diameter as the lead 3 can be drawn.

(Effects of the present invention) According to the tool of the present invention, the pressing force of the core 3 against the paper 10 is determined by the strength of the spring 9, the rotation angle is determined by the oblique elongated hole 6, and the tool is operated. Since it is unrelated to force, the density of a drawn black dot or black circle is always constant.

Furthermore, when drawing a black dot or black circle, the lead 3 does not shift laterally and become a short line, and the shape is always constant and beautiful.

Moreover, the darkness of the black dots and black circles can be arbitrarily adjusted depending on the hardness of the lead 3 and the strength of the spring 9, and the diameter of the black circle can be arbitrarily adjusted by changing the diameter of the lead 3, making the drawing operation extremely simple.

[Brief explanation of the drawing]

Figure 1 is a central vertical sectional front view of the device of the present invention;
The figure is a central longitudinal sectional front view of the tool of the present invention when the black dots have been drawn. 1...Pencil, 2...Shaft, 3...Lead, 4...Inner tube, 5...Cap, 6...Slanted long hole, 7...Outer tube, 8...Guide pin, 9...Compression Spring, 10...
Paper.

Claims (1)

[Scope of utility model registration request] A slanted elongated hole is bored at a key point in the shaft of a pencil with a retractable lead, and the pencil is fitted into the outer cylinder, which is shorter than the total length of the pencil, so that it can slide freely and both upper and lower ends protrude; A guide pin protruding inward from the outer cylinder is engaged with an oblique oblong hole, and a spring built into the outer cylinder urges the outer cylinder in the opposite direction to the lead of the pencil. Filling tools such as black circles.