CN103129261A - Multipurpose compass - Google Patents

Abstract

The invention relates to a multipurpose compass which comprises a compass body and an angle gauge. A rotating shaft center of the compass body is fixed with a zero of the angle gauge, and a straight scale is connected with a side edge of the angle gauge. Circle drawing auxiliary scales are arranged on the inner side of angle scales of the edge of the angle gauge. The outer edge of the circle drawing auxiliary scales is about 3-4 cm far from the rotating shaft center. A pen wall and a supporting wall of the compass are rectangle, and the lengths of the pen wall and the supporting wall of the compass are 8-10 cm. The multipurpose compass is an improvement of a traditional compass, and meanwhile has the functions of drawing circles with set semi-diameters, measuring angels and segments and drawing angles the like.

Description

Napier's compasses

Technical field

The present invention relates to a kind of study article, relate in particular to a kind of compasses.

Background technology

Compasses are student's requisite study articles in learning process, and a variety of compasses are arranged now on the market, and their purposes also has the purposes such as picture straight line except drawing circle.But generally we are using compasses to draw bowlder, need first to determine distance between two pin of compasses as radius of a circle with ruler, then begin the picture circle.The circular error that draws like this is larger, may affect student's study schedule.In addition, when the student took measurement of an angle at the use amount hornwork, the length of two rays at angle sometimes can be very short, could accurately measure angle by extending ray, and is cumbersome like this.

Summary of the invention

For the above-mentioned problem that can not accurately draw circle and measuring angle, the invention provides a kind of Napier's compasses.

A kind of Napier's compasses comprise compasses and protractor, and " 0 " point of the spindle central of described compasses and protractor is fixed together; Be connected with a ruler on the side of described protractor, the angle index inboard at protractor edge is provided with picture circle subscale mark, draws the outward flange of circle subscale mark apart from spindle central 3～4cm; A wall of described compasses and supporting walls are all rectangular shapes, and length is all 8～10cm.

Compared with prior art, the invention provides a kind of insulation leakproof glass holder, have following beneficial effect:

1. the design of ruler makes the student need not be with in addition the ruler just can slotted line segment length and setting-out again;

2. drawing the circle subscale mark can help the student to draw accurately the circle of radii fixus;

3. compasses pen wall and the supporting walls of rectangular shape, when taking measurement of an angle or draw certain angle, can overlap with two rays of angle, is convenient for measuring or setting-out.

4. the present invention has simultaneously picture and determines the circle of radius, measuring angle, amount line segment and draw the function such as angle, is fit to the student and uses.

Description of drawings

Fig. 1 is the schematic diagrames of Napier's compasses of the present invention when using as compasses.

The schematic diagram of Fig. 2 when to be Napier's compasses of the present invention use as protractor and ruler.

In figure: 1, compasses, 2, protractor, 3, ruler, 4, angle index, 5, draw the circle subscale mark, 6, a wall, 7, supporting walls.

The specific embodiment

Embodiment 1

The present embodiment provides a kind of Napier's compasses, comprises compasses 1 and protractor 2, and " 0 " point of the spindle central of described compasses 1 and protractor 2 is fixed together; Be connected with a ruler 3 on the side of described protractor 2, angle index 4 inboards at protractor 2 edges are provided with picture circle subscale mark 5, draw the outward flange of circle subscale mark 5 apart from spindle central 3cm; A wall 6 of described compasses 1 and supporting walls 7 are all rectangular shapes, and length is all 9cm.

Be the bowlder of 3cm when needing the picture radius, establishing the auxiliary length of picture circle is x, according to equation 3 ∕ 9 ﹦ x ∕ 3, tries to achieve x ﹦ 1.The scale " 1 " of again picture on supporting walls 7 and the left side being justified on subscale mark 5 aligns, and a wall 6 aligns with the scale " 1 " that the picture on the right is justified on subscale mark 5, begins the picture circle, and this moment, the gained radius of circle was 3cm.

Use the present invention to draw circle simple and convenient, and the circle that draws is more accurate.

Embodiment 2

The present embodiment provides a kind of Napier's compasses, comprises compasses 1 and protractor 2, and " 0 " point of the spindle central of described compasses 1 and protractor 2 is fixed together; Be connected with a ruler 3 on the side of described protractor 2, angle index 4 inboards at protractor 2 edges are provided with picture circle subscale mark 5, draw the outward flange of circle subscale mark 5 apart from spindle central 4cm; A wall 6 of described compasses 1 and supporting walls 7 are all rectangular shapes, and length is all 10cm.

When needs take measurement of an angle, protractor 2 one sides in protractor 2 belows, are overlapped spindle central with the summit at angle, a ray at angle all overlaps with the inner side edge of a wall 6, the base of protractor 2, another ray overlaps with the inner side edge of supporting walls 7, reads angle from angle index 4 and gets final product.

When to need angle of picture be the angle of 60 °, the inner side edge of a wall 6 is all overlapped with the base of protractor 2, the inner side edge of supporting walls 7 rotates to 60 ° of angle index 4 and locates, draw two lines along the inner side edge of a wall 6 and the inner side edge of supporting walls 7 respectively with pen, extend these two lines with ruler 3 again and obtain intersection point, just can draw angle and be the angle of 60 °.

In addition to the implementation, the present invention can also have other embodiments.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection domain of requirement of the present invention.

Claims (1)

1. Napier's compasses, comprise compasses (1) and protractor (2), it is characterized in that: " 0 " point of the spindle central of described compasses (1) and protractor (2) is fixed together; Be connected with a ruler (3) on the side of described protractor (2), angle index (4) inboard at protractor (2) edge is provided with picture circle subscale mark (5), draws the outward flange of circle subscale mark (5) apart from spindle central 3～4cm; A wall (6) and the supporting walls (7) of described compasses (1) are all rectangular shapes, and length is all 8～10cm.

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