CN2127913Y - Multi-purpose compasses - Google Patents

Abstract

The utility model relates to a multi-purpose compass used for measuring angles and drawing angles and circles. The multi-purpose compass is composed of two compass legs with circular discs; the two circular discs are concentric circles, wherein, one of the concentric circles is big, and the other is small; the two circular discs can mutually rotate around a circle center; the two compass legs respectively have one edge line passing the circle center. The utility model has the advantages that the multi-purpose compass integrates the functions of protractors and compasses into one body; the multi-purpose compass not only can measure and draw the angles, but also can draw the circles and measure the radiuses of the circles or spheres.

Description

Multi-purpose compasses

The utility model belongs to measurement, drawing instrument.

Prior art is used for draw circles and measures, draws the angle and utilize compasses and protractor to carry out respectively.The problem that exists is the function singleness of compasses and protractor, all can only measure or draw a kind of geometric figure.

The purpose of this utility model is to overcome the problem of the function singleness of compasses and protractor, provides a kind of and can measure, draw the angle can draw round Napier's compasses again.

The total design of the utility model is respectively with two of a compass foot small one and large one concentric discs, two disks can be that rotate mutually in the axle center with the center of circle, a sideline is respectively arranged by the center of circle in two compass foots, on two disks the scale of the angle measured is arranged or measure the scale of distance.

Illustrated in detail below in conjunction with accompanying drawing:

Accompanying drawing 1 structure chart of the present utility model;

Accompanying drawing 2 profilographs of the present utility model;

Accompanying drawing 3 measuring angle scale figure of the present utility model;

Accompanying drawing 4 spans of the present utility model are from scale figure;

Accompanying drawing 5 amount circle of the present utility model or radius of sphericity scale figure.

As shown in Figure 1, ［ 1 ］-big disk, ［ 2 ］-roundel, ［ 3 ］-compass foot that links to each other with big disk ［ 1 ］, ［ 4 ］-and the compass foot that links to each other with roundel ［ 2 ］, the handle of ［ 5 ］-link to each other, the turning cylinder of ［ 6 ］-fixing large and small circle disk center with big disk ［ 1 ］, the sideline of passing through the center of circle of the compass foot that a-links to each other with big disk, the sideline of passing through the center of circle of the compass foot that b-links to each other with roundel.0 ° of graduation mark is arranged on the big disk ［ 1 ］, and per 10 ° of central angles are a long graduation mark, and per 2 ° of central angles are a short graduation mark.0 ° of graduation mark is arranged on the roundel ［ 2 ］, and per 10 ° of central angles are a long graduation mark, and per 2.5 ° of central angles are a short graduation mark.As a, when the b sideline overlaps, 0 ° of graduation mark alignment on big disk ［ 1 ］ and the roundel ［ 2 ］.

As shown in Figure 3, when measuring or drawing the θ angle, 0 ° of graduation mark of roundel is between 8 °～10 ° of big disk, and roundel overlaps with a certain graduation mark of big disk from the 2nd graduation mark of 0 ° of graduation mark, then θ=8 °+0.5 ° * 2=9 °.

Big disk ［ 1 ］, the graduation mark of the distance measured is arranged above the roundel ［ 2 ］.On big disk, make the zero graduation line, Yi Bian serve as to get 60 ° of central angles with the zero graduation line, with these 60 ° of angle 30 five equilibriums.On roundel, make the zero graduation line, Yi Bian serve as to get 20 ° of central angles with the zero graduation line, and with approximate 9 five equilibriums of these 20 ° of central angles.As a, when the b sideline overlaps, the zero graduation line of large and small disk aligns just.

As shown in Figure 4, measure apart from the time, the zero graduation line of roundel refers between the 6th of big disk and the 7th graduation mark, the 7th graduation mark of roundel aligns with a certain graduation mark of big disk, l is the distance of the center of circle to the compasses tiptoe, d is the distance of two compasses tiptoes, then d=0.05l * 6+0.005l * 7=0.335l.If l=10cm is d=3.35cm so.

The utility model has tg θ/2=0.2,0.3,0.5,0.6,1 ... graduation mark

θ1＝2arctg0.2＝22.6°

θ2＝2arctg0.3＝33.4°

θ3＝2arctg0.5＝53.1°

θ4＝2arctg0.6＝62°

θ5＝2arctg1＝90°

The length graduation mark that starts from the center of circle is arranged on a, the b sideline.

When measuring circle or spheroid, with a go to a certain graduation mark positions aligning in tg θ/2 on, will justify or spheroid is placed between two compass foots, tangent with a, b, and two point of contact scales are equated.Write down the reading at point of contact, can predict the circle or the radius of spheroid according to R=Ltg θ/2, L is the reading at point of contact, and R is the radius of circle or spheroid.

Big disk, roundel can be made two blocks of plectanes; Also can make a large circle and a little plectane, the interior circle of large circle and the circumference of little plectane coincide; Also can make a large circle and a small circle ring, the interior circle of large circle and the cylindrical of small circle ring coincide.

The utility model has the advantages that the function with protractor and compasses is integrated in one, both can measure, draw angle, but draw circles again also can be measured circle or radius of sphericity.

Claims (3)

1, a kind of Napier's compasses that are used to measure, draw angle and circle, comprise two compass foots [3], [4], feature of the present utility model is that compass foot [3] is connected with a big disk [1], compass foot [4] is connected with a roundel [2], big disk [1] and roundel [2] have the same center of circle that can rotate around it, sideline a, the b of compass foot [3], [4] be by the center of circle, on big disk [1] and the roundel [2] scale of the angle measured arranged or measure the scale of distance.

2, Napier's compasses according to claim 1 is characterized in that on sideline a, the b of compass foot ［ 3 ］, ［ 4 ］ the length scale that starts from the center of circle being arranged, and tg θ/2 graduation marks are arranged on the big disk ［ 1 ］.

3, according to claim 1 or 2 described Napier's compasses, it is characterized in that there is a handle ［ 5 ］ upper end of great circle ［ 1 ］, big disk ［ 1 ］ and roundel ［ 2 ］ have and are used for fixing turning cylinder ［ 6 ］.

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