JPH10897A - Flat compass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw a circle by using a plate of transparent plastic, acryl or the like, forming two circular freely rotating disks inside, also forming a number of holes in respective rotating disks, inserting a lead of a pencil on one of the holes, pressing a fixed plate by a human left hand and rotating the rotating disks. SOLUTION: A fixed plate formed of a transparent flat plate and a large smoothly rotating disk are provided. A number of holes of diameter of 0.6mm are opened on the large rotating disk. Also a smoothly rotating small rotating disk is provided. A number of holes of diameter of 0.6mm are opened in the small rotating disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The flat compass of the present invention is made of a plate made of a material such as transparent plastic or acrylic. It has two circular rotating disks inside. Each rotating disk has a number of holes about 0.6 mm in diameter. Place the flat compass on the paper,
Insert a pencil (or mechanical pencil) into one of the holes, hold down the fixing plate with your left hand, and rotate the rotating disk to draw a circle. (For right-handed people). The large rotating plate is used for drawing a circle with a radius of 1.5 cm to a radius of 3.5 cm. Assuming a large rotating plate with a radius of 1.5
If you try to draw a circle less than a centimeter, the disk will not rotate easily. Circles with a radius of 1.5 cm or less are drawn using a small rotating disk. The rotating disk has a hole for inserting a pencil lead (a mechanical pencil is also acceptable). This hole has four types of holes from the classification on the arrangement. I will explain them. Type 1 A hole radiated from the center as shown in (4) of FIG. This is a hole for drawing a circle with a fixed radius. For example, if you want to draw a circle having a radius of 2.5 cm, insert the lead of a pencil into the hole marked 2.5 and rotate it. Type 2 Curved holes shown in (5) of (Fig. 6). This is a hole for drawing a circle through the designated point on the paper. The usage is to align the center of the drawing with the center of the rotating disk of the flat compass, then rotate the rotating disk with your finger to find a hole where the specified point matches the hole in the rotating plate, and insert a pencil The drawing is performed by inserting a core and rotating a rotating disk. Type 3 A hole shown in (6) of FIG. 6. Printing is performed as R. The usage of this hole is as follows. This is used, for example, when drawing a bisector of a corner. After drawing one circle from the center point of the corner to be bisected, draw an arc from the intersection with both sides. At this time, the two arcs need to have the same radius, but when you draw one and then the other, you may forget which hole you used. At this time, the use of the hole (6) will not be forgotten. Type 4 (FIG. 6) is shown in (7). These holes are used when drawing a circle with a radius that exceeds the radius that can be drawn with the large rotating plate. The usage is to hold the rotating disk with a finger and insert a pencil into the holes in the row of (7) to draw a circle. (FIG. 9) is an example of use of drawing a circle using the large rotating disk side. The same applies to drawing a circle using the small rotating disk side. For convenience of use, a protractor was provided on the upper part of the fixed plate, and ruler scales were provided on the left, right, and lower sides.

[0002]

2. Description of the Related Art Conventionally, when drawing a circle on paper, a needle-type compass has been used exclusively. The needle type compass has the following disadvantages. 1 When the balance between the force of the stylus and the force of the pencil was lost, the needles were lifted up and the drawing sometimes failed. Due to the nature of using two needles, a needle hole was made in the drawing paper. 3. When drawing a circle with a fixed radius, it was necessary to measure the dimensions from the ruler. Working with a compass with four hands was sometimes dangerous. 5 The operation of the screw to adjust the opening degree of the compass was troublesome.

[0003]

Since the flat compass does not use a needle, it can smoothly draw a circle without forming a needle hole in the paper and without causing the needle to float. It is safe because no needle is used. Even when drawing a circle having a fixed radius, a ruler for measuring the size is not required. Also, since it has no mechanical parts, it is not necessary to adjust with a screw and it is easy to handle. The present invention has been invented in order to meet the above demands.

[0004]

The configuration will be described. See FIG. (1) is a fixed plate made of a flat plate made of a transparent material. (2) is a large rotating disk which rotates smoothly. The large rotating disk has many holes with a diameter of 0.6 mm. (3) The small rotating disk rotates smoothly. The small rotating disk has many holes with a diameter of 0.6 mm.

[0005]

When the fixing plate is pressed with a finger, the lead of a pencil is inserted into a hole formed in the rotating disk, and then rotated, a circle can be drawn on the paper. In addition, pressing the rotating disk with a finger, inserting a pencil lead into a hole formed in the fixing plate, and rotating the disk, a circle can be drawn.

[0006]

EXAMPLE A protractor was attached to the upper part of a fixed plate, and a ruler scale was provided around the device for convenience in use. However, removing the ruler scale, the protractor, and the protractor scale around the fixed plate does not change the compass function for drawing a circle. Even if a small rotating disk is not used and only a large rotating disk is used as a fixed plate, the compass function for drawing a circle remains unchanged. In this case, the minimum radius value of the circle that can be drawn is large. The function of drawing a circle does not change in the following cases. The material from which the fixed and rotating disks are made. Size of fixed plate and rotating disk. The shape, number, arrangement and diameter of the holes drilled in the fixed plate and the rotating disk. A structure in which the fixed plate supports the rotating disk.

[0007]

Since the flat compass is made of a resilient transparent material, a circle can be drawn clearly even if the drawing paper is slightly uneven. In particular, when drawing a circle having a fixed radius, it is convenient because there is no need to measure the dimensions.

[Brief description of the drawings]

FIG. 1 is a front view, a bottom view, and a right side view of a scale 1: 1. The back view is omitted because it does not have any letter printing and the front view is completely inverted. The left side view is omitted because it is the same as the right side view. The plan view is omitted because it is the same as the back view.

FIG. 2 is a front view showing a printed surface. No printing is done on the back side.

FIG. 3 is a diagram showing component names.

FIG. 4 is a sectional view of a hole of a large rotary plate into which a pencil lead is inserted. The same applies to the one opened on the small rotating plate.

FIG. 5 is a sectional view of a portion where a fixed plate supports a large and small rotating disk. The central part is omitted because it is longer.

FIG. 6 is a diagram showing different types of holes.

FIG. 7 is a diagram for drawing a circle using a hole on a large rotating disk.

FIG. 8 is a diagram for drawing a circle using a hole on a small rotating disk.

FIG. 9 is a diagram in which a large rotating disk is fixed and the fixed plate is rotated to draw a circle.

[Explanation of symbols]

1 is a fixed plate, 2 is a large rotating disk, 3 is a small rotating disk, and 4 is a classification by hole type. A row of holes drilled radially from the center. 5 is a classification by hole type, which is a row of holes formed in a curved shape. 6 is a classification by hole type, fixed size holes. Reference numeral 7 denotes a classification by hole type, in which a row of holes is drawn by rotating a fixing plate.

Claims (1)

[Claims] 1. A compass that has a rotating disk in the center of a plate made of a transparent material, and inserts a pencil (or a mechanical pencil) into a hole formed in the rotating disk and rotates to draw a circle on paper.