JP3146926U - Circular protractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw a regular polygon or a circle in a free size by work, drawing, carpentry, dressmaking, dressmaking, patchwork, hobby, etc., and to measure or mark the center of a regular polygon or a circle Providing a protractor that anyone can easily do.
SOLUTION: A plurality of regular polygons are drawn on a circular protractor, a small hole is made at each vertex of the plurality of regular polygons, and a plurality of concentric circumferential lines and a plurality of radial scale lines are formed from the center of the circular protractor. The circular protractor is characterized in that a small hole is provided at each intersection of the center of the circular protractor and the circumferential line on the 0 degree line.
[Selection] Figure 1

Description

  The present invention is for anyone who can draw regular polygons in any size, such as work, drawings, carpentry, dressmaking, dressmaking, patchwork, hobbies, etc. But it's about a circular protractor to make it easy.

  Traditionally, when trying to draw a regular polygon or a circle, the angle was calculated, and then using a protractor or a compass, it took a lot of time, and the distance to the center of the circle was measured and marked. The diameter was measured, the radius was calculated, and a compass was used.

Therefore, there were the following problems.
(B) It was difficult to mark the center of the regular polygon or circle being drawn, and to measure the diameter and radius to the center.
(B) When drawing a regular polygon, it took time and effort to calculate the angle, mark with a protractor, measure the diameter and radius, and then use a compass.
In order to solve the above-mentioned problems, the present invention provides a concentric circumferential line that is radially spaced from the center of the circular protractor at equal intervals. It is a circular protractor with a known radius.

  A plurality of regular polygons starting from an equilateral triangle are drawn on the main body, and a small hole is made at the intersection of the circumference line concentric with the vertex of the regular polygon. You can draw a regular polygon easily by connecting with.

  The angle of one side of the regular polygon can be determined by starting the vertices of a plurality of regular polygons starting from the regular triangle from 0 degrees.

  In addition, a regular polygon of any size can be drawn by marking the same distance on the line of each vertex hole of the regular polygon and the center hole.

  A plurality of regular polygons are drawn on the circular protractor, and a small hole is made at each vertex of the plurality of regular polygons. Each vertex of the regular polygon starts from 0 degree, and a plurality of concentric circumferential lines and a plurality of radial scale lines are provided from the center of the circular protractor. A small hole was provided at each intersection of the center of the circular protractor and the circumferential line on the 0 degree line. A circular protractor characterized by the above.

  If you apply the circular protractor and move it up, down, left, or right, you can see the center and the radius distance to the center. It is also possible to mark the small hole in the center, and if you mark the small hole at each vertex of the regular polygon and connect it with a line without using the angle calculation and compass, it is easy for anyone to freely A regular polygon can be drawn. You can also write a circle by fixing the central small hole, putting a pencil or ballpoint pen into the small circular hole, and rotating it.

  Compact and compact, it takes up little space and is easy to carry, making it ideal for outdoor workplaces, leisure and hobbies.

Embodiments of the present invention will be described below.
(A) Concentric circumferential lines (3-7) (39-42) are provided from the center of the circular protractor body (1) of FIG. 1 at a radial interval of 5 mm from the radial scale lines (8-15) of FIG.
(B) The circular protractor body (1) of FIG. 1 has a circular small hole (34 to 34) in FIG. 4 at the intersection of the central small hole (2) of FIG. 3 and the circumferential lines (39 to 42, 7) on the 0 degree line. 38).
(C) A plurality of polygons starting from an equilateral triangle are drawn on the circular protractor body (1) of FIG. 1 starting from 0 degree of FIG. 4, and the circumference lines (3 to 6) are concentric with each vertex. Small holes (16 to 33) are provided at the intersections.
(2) The material of the circular protractor body (1) in FIG. 1 is metal, transparent synthetic resin, and recycled plastic bottles are also good considering the environmental problem. Each small hole has a diameter of 0 that allows the tip of a sharp pen or ballpoint pen to enter. About 5 to 2 mm is good.
(E) The circular lines (3 to 7) and (39 to 42) concentric with the radial scale lines (8 to 15) of the circular protractor body (1) in FIG. Enter the number of distances.
The present invention has the structure as described above. When this is used, the protractor body (1) of FIG. 1 is applied to a circular or regular polygonal object, moved up and down, left and right, and its circumference and vertex are shown. The center of the circle or regular polygon can be found by aligning the radial scale line (8-15) from the center of 3 and the circumferential lines (3-7) (39-42) concentric with the distance from the center. 3 can be marked in the central small hole (2) in FIG.

  Hold the center small hole (2) in FIG. 3 of the circular protractor body (1) in FIG. 1 with a pencil or ballpoint pen, etc., and the small circular holes (34 to 38) in FIG. By drawing a pencil, ballpoint pen, etc. in the holes (16, 19, 23, 28) and rotating, the same circle as the concentric circumferential lines (3-7) (39-42) can be drawn at a radius of 5 mm. it can.

  When writing an equilateral triangle from the polygon drawn on the circular protractor body (1) of FIG. 1, the equilateral triangle vertex hole (16, 17, 18) of FIG. Mark the holes (19-22), regular pentagons with regular pentagonal small holes (23-27) in FIG. 4, regular hexagons with regular hexagonal small holes (28-33) in FIG. If you connect it with a line, you can draw the regular polygon you like.

  Also, select the regular polygon you like, mark the regular polygonal apex holes with a pencil or ballpoint pen in the same way, and mark the center small hole (2) in Fig. 3 with the same distance on the line If you mark and connect with lines, you can draw a regular polygon of any size.

Plan view of the present invention Cross section of the present invention The top view which shows the principal part of this invention The top view which shows the principal part of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circular protractor main body 2 Center small hole 3-7, 39-42 Circumferential line 8-15 Radial scale line 16-18 Equilateral triangle apex small hole 19-22 Regular tetragonal apex small hole 23-27 Regular pentagonal apex small hole 28- 33 Regular hexagonal small hole 34-38 Circumferential hole

Claims (3)

  A circular protractor characterized in that a plurality of regular polygons are drawn concentrically at the center of the disk, and a small hole is provided at the intersection of each vertex of the regular polygons and a plurality of circumferential lines.   The circular protractor according to claim 1, wherein a plurality of scale lines are provided radially from the center.   3. A circular protractor according to claim 1, wherein a small hole is provided at each intersection with a circumferential line on the same radial line as the center.

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