Magnetic type circle-drawing precision instrument

Abstract

The invention relates to the technical field of teaching appliances, in particular to a magnetic type circle-drawing precision instrument. The magnetic type circle-drawing precision instrument comprises a center body and a radius measuring scale. The center body is provided with a plane capable of being in touch with a plate body, a cavity provide with a magnetic body is arranged on the center body, a circle center positioning mechanism is arranged at the center position of the center body, the circle center positioning mechanism is used for arranging a pen for drawing a circle center, a scaleplate with a 360-degree angle is fixed to the center body, the radius measuring scale freely rotates around the center line of the center body, and a connecting unit provided with a circle-drawing pen for drawing an arc line is arranged at one end of the radius measuring scale. The magnetic type circle-drawing precision instrument is absorbed on a blackboard by using magnetism, the circle centerposition is marked, circles with any accurate radius length can be drawn through scales on the radius measuring scale, arcs with any angle can be measured and cut by the radius measuring scale by combining with angle indexes, the operation is convenient, and the accurate and distinct circles can be rapidly drawn.

Description

technical field [0001] The invention relates to the technical field of teaching appliances, in particular to a magnetic suction type circle drawing precision instrument. Background technique [0002] Existing teaching aids for drawing pictures on a blackboard are usually compasses. The gauge body of the compasses mainly consists of two gauge rods. The upper end of the rod is hinged, and the lower end can be separated or closed at will to adjust the size of the radius of the arc drawn. In daily teaching use, there are many deficiencies in existing teaching aid compasses: [0003] 1. There is no length scale, and the radius length of the drawn circle cannot be displayed. If you want to draw a circle with a given radius, you must use a scale; [0004] 2. There is no angle scale, and it is impossible to draw, measure, and intercept arcs at any angle; [0005] 3. The rubber cone of the compass does not fix the center of the circle firmly, and it is easy to shift when drawing a...

AI Technical Summary

Problems solved by technology

[0003] 1. There is no length scale, and the radius length of the drawn circle cannot be displayed. If you want to draw a circle with a given radius, you must use a scale;

[0004] 2. There is no angle scale, and it is impossible to draw, measure, and intercept arcs at any angle;

[0005] 3. The rubber cone of the compass does not fix the center of the circle firmly, and it is easy to shift when drawing a circle, especially on a relatively smooth whiteboard. It is often necessary to hold the rubber cone with one hand to prevent displacement, and the other hand Turn the animation circle by hand, and the speed of drawing the circle is slow, and it is difficult to operate with one hand

Because the center of the circle is not fixed firmly, it is easy to shift and cannot use force, which often causes the handwriting of the drawn circle to be thinner and lighter, and not clear enough;

[0006] 4. The installation of the chalk is troublesome, and the length of the chalk becomes shorter after use, so it is difficult to adjust the length of the chalk;

[0007] The above-mentioned defects will cause the compass to greatly reduce the teaching quality and efficiency in actual use. In view of the above-mentioned defects, it is urgent to provide a circle-drawing instrument that can quickly and accurately draw circles or arcs at any angle, so as to improve the drawing efficiency of the painter. To improve teaching quality and efficiency

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