CN2844846Y - Apparatus for measuring radius of circular arc - Google Patents

Abstract

The utility model relates to a kind of apparatus for measuring radius of circular arc, comprises protractor, ruler and rotating shaft, offers a center line on ruler; Protractor axle center and ruler zero graduation position link together by rotating shaft, and the datum line of protractor is aimed at the center line of ruler; Magnifier is installed in the position of corresponding amount hornwork scale value on ruler.When using, the user only needs the effect of throughput hornwork and ruler to collect the length of DA, DB, DC and the number of degrees of two angles, then these data is brought into formula

In can draw the length of circular arc radius.The utlity model has advantages such as rational in infrastructure, convenient and practical, that use is extensive, measurement is accurately quick, and save time and operation, can effectively increase work efficiency.

Description

Apparatus for measuring radius of circular arc

Technical field the utility model relates to a kind of survey instrument, the especially a kind of new type measuring instrument that can measure arc radius.

Technical background is when teaching and building, and people often use various survey instruments that structure and figure are measured.But but there is not a kind of survey instrument to measure the radius of circular arc quickly and accurately at present, people must use multiple instrument combined measurement and calculate various data and can draw arc radius, when application operating, bother unusually and have a gross error, make troubles for teaching and work.

The summary of the invention the purpose of this utility model provides a kind of apparatus for measuring radius of circular arc, is used to solve the common survey instrument problem of measurements and calculations arc radius fast.

For achieving the above object, the utility model apparatus for measuring radius of circular arc comprises protractor, ruler and rotating shaft, offers a center line on ruler; Protractor axle center and ruler zero graduation position link together by rotating shaft, and the datum line of protractor is aimed at the center line of ruler; Magnifier is installed in the position of corresponding amount hornwork scale value on ruler.

After adopting said structure, appoint in plane, circular arc place and get 1 D as the measuring center point, the protractor axle center is placed on the D point, rotate whole measuring instrument, make the ruler center line of original state and circular arc that an intersection point A be arranged, the length of reading DA on ruler is " X "; Fix protractor, rotate ruler again, make its center line and circular arc that another intersection point C be arranged, the length of reading DC is " Y "; Measure the angle " ∠ α " of DC and DA with protractor; Rotate ruler once more, make its center line and circular arc that intersection points B be arranged, measure DB length for " Z ", measure the angle ∠ β between the extended line of DB and AD with protractor, bring these data into formula:

$R=\sqrt{\frac{X^2+Y^2-2\mathrm{XYCOS\α}}{4-\{1-{\left[\frac{{2Z}^2+2\mathrm{XZCOS\β}+2\mathrm{XYCOS\α}+2\mathrm{YZCOS}(\mathrm{\α}+\mathrm{\β})}{2\sqrt{[Z^2+Y^2+2\mathrm{YZCOS}(\mathrm{\α}+\mathrm{\β})][X^2+Z^2+2\mathrm{XZCOS\β}]}}\right]}^2\}}}$ In can draw circular arc

The length of radius.

The utility model has the advantages that: rational in infrastructure, convenient and practical, use extensively, measure accurately fast, and save time and operation, can effectively increase work efficiency.

Description of drawings Fig. 1 is the one-piece construction synoptic diagram of the utility model apparatus for measuring radius of circular arc.

Embodiment as shown in Figure 1, the utility model apparatus for measuring radius of circular arc comprises protractor 1, ruler 2 and rotating shaft 3, offers a center line 4 on ruler 2; Protractor 1 axle center and ruler 2 zero graduation positions link together by rotating shaft 3, and the datum line of protractor 1 is aimed at the center line 4 of ruler 2; Magnifier 5 is installed in the position of corresponding amount hornwork 1 scale value on ruler 2.Wherein, general instrument got final product during protractor 1 and ruler 2 adopted and impart knowledge to students.When using, the user only needs the effect of throughput hornwork 1 and ruler 2 to collect the length of DA, DB, DC and the number of degrees of two angles, then these data is brought into the length that can draw the circular arc radius in the formula.

Claims (1)

1, a kind of apparatus for measuring radius of circular arc comprises protractor (1), ruler (2) and rotating shaft (3), it is characterized in that: offer a center line (4) on ruler (2); Protractor (1) axle center and ruler (2) zero graduation position link together by rotating shaft (3), and the datum line of protractor (1) is aimed at the center line (4) of ruler (2); Go up the position of corresponding amount hornwork (1) scale value at ruler (2) magnifier (5) is installed.