Indexer

Abstract

The features of this protractor are as follows (1) and (2): (1) In the front view, the outer periphery of the full circle is marked clockwise with an angle scale ranging from 0° to 360°, and in order to make the 1° markings easier to see and measure, the 5° markings are made longer than the other marks every 10°, and a stepped scale is formed with the 1° markings being the shortest and the 2° markings and subsequent marks successively longer until the 10° markings are the longest. Of the stepped scales, the 2° markings, 4° markings, 6° markings, and 8° markings at each of the 10° markings are filled in with circles larger than the width of the markings to form easy-to-see circular scales. In addition, the numbers "0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350" are displayed for each 10° scale unit, with a light red band behind them to make the numbers easier to read. Furthermore, the top of each half (5°) of each 10° scale unit is filled in with a red inverted triangle to form easily identifiable inverted triangular scale marks. (2) In the rear view, the outer periphery of the full circle is marked counterclockwise with an angle scale ranging from 0° to 360°. To make the 1° markings easier to see and measure, the 5° markings are made longer than the other markings, and a stepped scale is formed in succession, with the 1° markings being the shortest and the 2° markings and subsequent marks successively longer until the 10° markings are the longest. Of the stepped scales, the 2° markings, 4° markings, 6° markings, and 8° markings in each of the 10° markings are filled in with a circle at the top, larger than the width of each marking, to form easy-to-see circular scales. In addition, the numbers "0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350" are displayed for each 10° scale unit, and a light blue band is displayed behind them to make the numbers easier to read.In addition, the top of each half (5°) scale marking for each 10° scale unit is filled in red to form an inverted triangle-shaped scale marking that is easy to identify.

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