JPS6039272Y2 - Protractor with angle scale on a straight line - Google Patents

Description

[Detailed description of the invention] This invention relates to a protractor. Focusing on the fact that in the same circle, the size of the circumferential angle and the length of the circumference are directly proportional, the main protractor piece a and the width The protractor pieces are pivoted so that they can slide at the same center O, and the width protractor piece and the subscale piece C are connected to the circular arc part of the width protractor piece and the straight and elongated guide groove d of the main protractor piece. Since the structure is connected by a rack mechanism at each point, if the protractor piece is rotated in the normal and reverse directions at the heir part 6, the vernier piece will slide linearly from side to side within the guide groove in accordance with the movement. If you move or, conversely, slide the width piece from side to side at one end of the width piece, the knob piece opens and closes in a rotational manner.

In addition, in order to eliminate the gap that occurs at the connecting point 8, a constant tensile force is always applied, and the level difference between the main protractor piece and the width protractor piece is eliminated to maintain a horizontal state. Furthermore, the diagram shows that the width protractor piece can be fixed to the angle measurement diameter, e is a rubber string, f is a thread, f' is an arc-shaped curved edge with the center O, and P and Q are either is a screw that fixes the end of the thread like a rubber string, K is a step correction plate, 11 is a long groove, 1
2 is a thumbscrew.

(1) Angle scale 1 and 1' of the main scale of the main protractor piece a
and the interval between the scales 2 of the width protractor piece C are 1 of the circumference of a circle with a radius r centered on the axis O of the circular arc part of the width protractor piece C.
Since the length of a straight line is 1/9 and 1110, respectively, which is equal to the length of /4, the angle scale at 1 and 1' is the number of angles of the central angle, 0°, 10°...90' and 180. °, 170°・
...90° in 10° increments, and the scales are shown as mutually complementary angles, and when one angle is drawn, the sum of that angle and the opposite angle is always the circumferential angle. number of angles of 360°
Therefore, as shown in the figure, the scale can display all the circumferential angles between 0° and 360° in units of 10°.

The number of scale marks of width scale scale 2 is 0.1.2...10 and 1, respectively.
0.9...0, and the upper and lower numbers are displayed as complements of lO, so by reading the main and vernier scales together, it is possible to accurately measure angles in units of 10.

The unit of angle can be made even smaller by dividing the scales of the main scale and vernier scale into even smaller scales, or by moving the vernier scale piece using a mechanism similar to that of a conventional micrometer.

In addition, two gears, large and small, are fixed on the same shaft, and the small gear is connected to the gear on the arc part of the width protractor piece, and the large gear is connected to the rack mechanism of the width protractor piece at 8 points so that they mesh with each other. For example, the interval between the scales can be increased to 1.1' or 2 equal to the value of the ratio of the radii of the large and small gears, so the scales can be easily seen and the accuracy of angle measurement can be increased.

In addition to the pointer 7 that the width piece has, another pointer is attached to another location on the width piece, and a cassette frame is provided at the top of the main protractor piece so as to correspond to this pointer, and each scale plate prepared in advance is attached. By making it possible to insert and replace , it can be used to easily draw various regular polygons, pie charts, etc.

(2) The main protractor piece a of this product has a side 4 parallel to the horizontal base line 10 passing through the center O, and 10 and Za
A protractor piece 6 is connected to the left side of the width protractor piece, which has a side 5 with a waist and a side 4' that is in contact with 4 as the lower edge, and a side 5' that is in line with 5 as the upper edge. Therefore, the pointer 7 indicates the angles of Za', Zβ' as well as ZaXZβ formed by the horizontal base line 10 and the base line 3 of the width protractor piece a. La and Za' can be directly drawn using side 4 and side 4' of the width protractor piece, and similarly Za and Zβ' can be directly drawn using sides 5 and 5'.

Among the four angles indicated by drawn lines, Za and Za are mutually complementary angles, and la and Za' as well as Za and Zβ' each form a circumferential angle whose sum is 3600. .

In order to accurately find the center of the desired angle, two small holes m and n are provided in the main protractor piece a and the width protractor piece as shown in the figure so that they are on a straight line passing through the center O. , o Let n' be n', m' and Q, n' and 0
By connecting the mutually complementary angles indicated by the pointer 7, that is, 1mom=la and lnom'=la, and Za'=Zm'on, whose sum with Za becomes 3600, and Z
This means that the four corners of Zβ'=ZnOm' where the sum with a is the same <360° can be shown as drawn lines.

Since the protractor has a structure coupled with the above-mentioned concept and operates in the same way, the angle scale is easier to see, the angle drawing line is accurate and quick, and the scale is attached on a straight line. , it is possible to arbitrarily divide any angle into equal parts, to draw various regular polygons of any size, and to display angles with radicals as drawing lines.

[Brief explanation of the drawing]

The figures show an example of the present invention. Figure 1 is a front view of the product, Figure 2 is a front view showing the product in use, and Figure 3 is a front view of the back of the product. . In the figure, O is the center of the shaft, a is the main protractor piece, b is the width protractor piece, C is the width piece, d is the guide groove, e is the rubber string, f is the thread, 1
In addition, 1' is the angle scale, 2 is the vernier scale, 3 is the base finger line, and f'
is an arc-shaped curved edge, P is a rubber string fixing screw, Q is a thread fixing screw, 10 is a horizontal base line, 6 is a legitimate piece, 7 is a pointer, 4 and 4'
is a side parallel to the horizontal base line, 5 and 5' are sides forming Za with the horizontal base line, 8 is a contact part of the tooth part, m and n are small holes, and K is a step correction plate.

Claims (1)

[Scope of utility model registration request] Sides 4 and 4' parallel to the base line 10 passing through the center O, and the center O
A main protractor piece a1 having sides 5 and 5' circumscribing the circle of
The sub-protractor piece has three vernier pieces C attached to it, a and b are pivoted so as to be able to slide on the same center, b has a circular arc part and a legitimate child part 6, and C has a circular arc part and a heir part 6. Existing in the elongated guide groove, b
C moves left and right according to the rotation of the circular arc part of C, and the pointer of C, which moves left and right through the mediation of gears, rack mechanisms, or four cables, displays the rotation angle of b and at the same time moves the drawing line side 4.
and 4', as well as 5 and 5', the structure of a protractor with an angle scale on a straight line that allows you to draw the angle as shown.