CN2293793Y

CN2293793Y - Vernier protractor

Info

Publication number: CN2293793Y
Application number: CN 97203849
Authority: CN
Inventors: 李传安
Original assignee: 成谢锋
Priority date: 1997-01-11
Filing date: 1997-01-11
Publication date: 1998-10-07
Anticipated expiration: 2007-01-11

Abstract

The utility model discloses a vernier protractor which is a measuring tool which can be used for accurately measuring angles and radians. An ordinary protractor can only be used for accurately measuring to the bit of 'a degree '. The utility model is mainly composed of two parts of an angular measurement scale disk and a vernier. The vernier is made into a fan shape and the radius of the vernier is slightly smaller than the radius of the scale position of the angular measurement scale disk. The center of a circle of the vernier is superposed with the center of a circle of the angular measurement scale disk. A thin shaft is penetrated through each center of a circle and is sued for fixing the vernier and the angular measurement scale disk. The vernier can be appressed with the plane of the angular measurement scale disk and is rotated around a fixed shaft. The working principle of the vernier is used for accurately measuring to the bit of 'a fractile'. The utility model has the advantages of simple manufacturing process, convenient use and wide use and is an advanced tool for study and measurement.

Description

Vernier protractor

The utility model is a kind of can taking measurement of an angle more accurately and the survey instrument of radian.

In people's work and study, the usual amounts hornwork takes measurement of an angle, radian, but the scale division value of general quantity hornwork is 1 degree, can only accurately survey read " degree " this, can only estimate and read spending following numerical value.The utility model utilizes the principle of work of vernier, can survey more accurately and read " branch " this position.

The utility model mainly is made up of angulation dial and vernier two parts.It is fan-shaped that vernier becomes, and its radius is slightly less than the radius at angulation dial scale place.The center of circle of vernier overlaps with the garden heart of angulation dial, and a thin axle passes the garden heart the two is fixed, and vernier can be close to the plane of angulation dial around this stationary shaft rotation.Angular readings is to be showed by the arc distance between vernier 0 degree line and the angulation dial 0 degree line.

The utility model in constructional principal feature is: establish the arc length that M represents a lattice on the angulation dial, N represents the arc length of a lattice on the vernier, the arc length of P lattice is to equate with the arc length of (P-1) individual lattice on the angulation dial on the vernier, PN=(P-1) M is promptly arranged, δ N=M-N=1/P.Facts have proved, be good between P=10～60.When P=10, the arc length of 10 lattices equals the arc length of 9 degree on the angulation dial, δ N=0.1 degree on the vernier.When vernier 0 degree line overlaps with angulation dial 0 degree line, article one scale mark of article one scale mark and angulation dial differs 0.1 degree on the vernier, the second scale mark of second scale mark and angulation dial differs 0.2 degree on the vernier, by parity of reasoning, and Here it is, and the utility model utilizes vernier to improve the theoretical foundation that precision is read in survey.When being angle of 20.5 degree when taking measurement of an angle, 0 degree line of angulation dial overlaps with a limit at this angle, 0 degree line of vernier overlaps with another limit at this angle, reading integer-bit from vernier 0 position of degree line on the angulation dial is 20 degree, again from the numerical value below the vernier degree of reading, this moment, the 5th line of vernier overlapped fully with certain bar line of angulation dial, so reading is 0.5 degree, this angle angle is the 20+0.5=20.50 degree like this.When P=60, the measured number of degrees directly are what how much to be spent divide, and have given prominence to=60 minutes system of 1 degree relation.

The utility model plastics manufacturing, technology is simple, and is easy to use extensive, is fit to make the instrument that measure of learning is used.

Accompanying drawing has provided embodiment of the present utility model.

Vernier protractor structural representation as shown.

Wherein: 1 angulation dial.2 angulation dial scales.3 verniers.4 vernier graduations.5 stationary shaft.

In the drawings, the center of circle of vernier 3 overlaps with the garden heart of angulation dial 1, and the two axle 5 that is fixed is fixing, but vernier 3 can be close to the plane of angulation dial 1 around stationary shaft 5 rotations.Angulation dial scale 2 is scribed by the scale of standard volume hornwork.Vernier graduation 4 is by P=60, the M=1 degree, and the formula of N=(P-1) M/P is determined.

Claims

1. vernier protractor is a kind of can taking measurement of an angle more accurately and the survey instrument of radian, it is characterized in that: vernier protractor is made up of angulation dial and vernier two parts, it is fan-shaped that vernier becomes, its radius is slightly less than the radius at angulation dial scale place, the center of circle of vernier overlaps with the garden heart of angulation dial, one thin axle passes the garden heart the two is fixed, and vernier can be close to the plane of angulation dial around this stationary shaft rotation.