JPH0310193A - Gnomon - Google Patents

Abstract

PURPOSE:To measure correct time along with a simple setting while providing a type able to carry by setting a bearing gauge to a bearing indicating section formed integral on a base to set a bearing of a gnomon accurately. CONSTITUTION:This apparatus is made up of an almost cylindrical display section 2 with a time graduation 202, a shadow bar 3 for making a shadow as arranged almost at the center of the cylinder geometry, a base 5 for holding the shadow bar 3 and the display section 2 and a bearing indicating section 4 formed integral on the base 5. The surface 501 of the base 5 has a latitude/ equation of time correction table 6 in which a correction value is give in a graph to determine Japan standard time and a setting surface 502 is provided on the side opposite to the surface 501 to set a gnomon 1 on the ground. Then, a bearing gauge is set on a bearing indicating section 4 formed integral on the base 5 and a bearing of the gnomon 1 is set accurately. By reading a posi tion of a shadow on the display section 2 made with the shadow bar 3, time can be learned every second.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sundial that can tell the current time based on the position of the shadow of a ridge line that is approximately parallel to the earth's axis.

[Conventional technology]

The idea of trying to determine the current time by using the position of the sun's shadow based on the movement of the sun throughout the day has existed since ancient times.
Even these days, in parks and other places, there are things that draw an arc on the ground and set up a stick to make a cedar tree in the center, and tell the time by the shadow of this stick.

Also, as you can see in parks, etc., you can make a semicircular and cylindrical time display part out of cement, put a stick on the line connecting the centers of the cylindrical flat parts, and then set the time at the position of the shadow created on the cylindrical surface. This is what I am trying to display.

[Problem to be solved by the invention]

The above items are large ones that are installed in parks etc.
Once installed, it will never be moved. Therefore, it depends on which region and where the installation location is installed.
If you calculate the latitude and longitude in advance and set the direction, the position will not change from then on, so you can know the time accurately.

However, if you try to make a tabletop type sundial or a portable one (even if it is slightly thicker than the tabletop type), you will have to reinstall the sundial each time you carry it, and when installing it, you will need to This means that the latitude, longitude, direction, etc. must be reset each time, and a separate device must be prepared for this purpose.

In view of the above-mentioned viewpoints, an object of the present invention is to provide a sundial that is of a portable type, can be easily installed, and can accurately measure time.

[Means to solve the problem]

The gist of the present invention to achieve the above object is to provide a substantially cylindrical display section with a time scale, a cylindrical shadow bar placed at the center of the screen for creating a shadow, and a shadow bar and display section. It consists of a pedestal that holds the pedestal, and a compass arranging section that is integrally formed on the pedestal.It also has a correction function corresponding to latitude and longitude, and also has a display section, pedestal, and compass arrangement section that is integrally formed with the pedestal. The device is characterized in that the arrangement portion is formed so as to be assembled by bending a single plate.

[Effect]

According to the above configuration, a compass is installed in the compass arranging section that is integrally formed on the base to accurately align the direction of the sundial, and the position of the shadow cast by the shadow bar on the display section is read. It allows you to know the time at any given time,
The sundial can be easily installed by the above method no matter where the sundial is carried.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

Figure 1 is a perspective view showing the sundial of the present invention, Figure 2 is a developed view of Figure 1, Figure 3 is a plan view of the display section with the time scale enlarged, and Figure 4 is the declination scale. FIG. 3 is an enlarged plan view of the display section.

1 is a sundial of the present invention. Reference numeral 2 denotes a display section, which will be described in detail later, but has a substantially semi-cylindrical shape, and has a time scale 202 on the circumferential inner surface 201 of the cylindrical surface. Reference numeral 3 denotes a shadow rod, which is fixed by the cylindrical center portions 205, 206 of the cylindrical planes 203, 204 of the display section 2 and a holding hole 504 of the pedestal, which will be described later. There is a shadow piece 60 approximately on the display part 2 of the shadow stick 6.
1 is fixed. 4 is a direction indicator, with N (north) on the cedar bar 6 side on a straight line from the shadow bar 6, and S (north) on the side opposite to the shadow bar 3.
South) forms (Yo 5), W (west), E ( at right angles to N-8).
It has an orientation display section 401 in which "East" is written. Reference numeral 5 denotes a pedestal that holds the display section 2 and shadow bar 3 and integrates the direction indicating section 4. On the surface 501 of the pedestal 50, a longitude and equation of time correction table 6, which is a graph of correction values for determining Japan Standard Time, is written, and on the opposite side from the surface 501, a table 6 for setting the sundial 1 on the ground is written. It has an installation surface 502. The sundial 1 shown in FIG. 1 is adjusted to a latitude of 35°N so that it can be used in Tokyo.

FIG. 2 shows a developed view of FIG. 1, but to be more precise, it is a developed view in which not only the longitude graph can be corrected, but also the latitude can be corrected.

The sundial 1 will be explained in more detail with reference to FIG.

The display unit 2 has a time scale 202 from 6h to 18h, and the numbers are graduated so that the solar time with the meridian at 12 o'clock is measured. Also, several lines are drawn parallel to the longitudinal direction of the display section 2, and these lines are called declination lines 208, allowing the user to know the position of the sun depending on the season. Declination line 208 is -23.5° to +23.5° from above
', and the center line is the celestial equator line 2.
07, and at the time of the vernal or autumnal equinox, the shadow of the sun almost coincides with this line. The line at -23.5° is called the winter solstice line 209, and the sun's shadow falls at this position during the winter solstice.

The line at +23.5' is called the summer solstice line 210, and the sun's shadow points to this position during the summer solstice. In addition, the longitudinal end of the display section 2 is called a latitude line, and the line of intersection with the horizon is 25°N to 4° so that the position of the cut curve can be changed depending on the latitude of the area.
Scales up to 5"N are attached to both ends. Latitude lines 212 and 216 are also attached to the cylindrical planes 203 and 204, respectively, and the cylindrical planes 206 and 204 are aligned with the latitude line 211 of the display section 2. The latitude lines 212 and 216 are also cut out to form a latitude adjustment mechanism.Furthermore, the installation surface 502 of the pedestal 5 also has latitude lines 25°N to 45°N.
is listed, and the installation surface 5 depends on the latitude of the area.
This is one of the latitude adjustment mechanisms that can change the shape of 02.

Next, on the front surface 501 of the pedestal 5, correction values for determining Japan Standard Time are graphed, forming a longitude and equation of time correction table 6 in which curves corresponding to longitudes are drawn. The horizontal axis of the longitude and equation of time correction table 6 shows the name of the calendar month (January, February, etc.), and the vertical axis shows the longitude, and a curve that can be corrected in minutes according to the longitude is displayed. has been done. The longitudes displayed are from 125°E to 145°E. As long as the latitude and longitude are within the latitude and longitude ranges of this embodiment, the sundial of the present invention can be used all over Japan, and the Japan Standard Time in that area can be known.

Next, the azimuth display section 401 of the azimuth indicator 4 has a declination display section 402 indicating the declination of the earth's magnetic field. Eight poles are now required.

In addition, the three black circle parts 214 and 215 shown in FIG.
．． 504 is a hole for holding the shadow rod 6. Further, 217.51]5 is the glueing process when assembling the sundial in the perspective view of FIG. Furthermore, for the perspective view of the sundial shown in Figure 1, as shown in Figure 2, a developed view is drawn on a single board, and the outer periphery is cut out while being careful not to separate it.
By assembling using glue 217 and 505 and attaching the shadow rod 6, the sundial 1 as shown in the perspective view is completed.

Next, a method of reading time using the sundial 1 will be explained.

First, cut out the outline of a sundial from a piece of board shown in Figure 2, and cut it out to match the latitude of the area where each latitude line 211, 212, 216, 502 will be attached: 139° 4440°.
9 E (former Tokyo Observatory in Azabudai, Minato-ku), so all lines of latitude are cut at 35°N.

Note that the latitude lines 211 at both ends of the display section 20 are preferably not straight lines but approximate sine curves whose inflection points are intersections with the celestial equator line 207.

Now, by assembling this, the sundial 1 shown in FIG. 1 is obtained.The first method of installing the sundial 1 is to sect a compass to the compass display section 401 of the compass indicator section 4. and the magnetic N
If you set sundial 1 so that it is on the line of the local geomagnetic declination (Tokyo is 6° 24.18W, so the guideline is 6° 30 westward) in the direction that the polar needle is pointing, you can now see the sundial. Set 1 is completed.

Next, regarding how to read the time, Figure 3 shows a time scale with 12 o'clock on the meridian, allowing you to read the solar time.

When sunlight hits the shadow bar 6, the shadow of this shadow bar 6 appears on the display section 2.
It can be formed on the circumferential inner surface 201 of. Since a time scale 202 is attached to the circumferential inner surface 201, the shadow 602, which is the visible solar time at that time, can be read as 13:20 from the number on the time scale 202 to know the time. Since this time is in diachronic time, Japan Standard Time can be determined using the longitude and equation of time correction table 6. Next, this method will be explained.

Longitude and equation of time correction table 6 shows equation of time and Japan standard time longitude,
Contains both the longitude difference with ii (135°E),
Just one graph can be used all over Japan. It is assumed that the shadow 602 that corresponds to the visual interval shown in FIG. 3 is 13:20. If the longitude of Tokyo is 139°44 and the current calendar is the first day of June, then the line drawn from the longitude of about 140°E in the longitude and equation of time correction table 6 and the beginning of JUN (June) on the month display. Find the intersection between the intersection point and the curve on the graph. In this embodiment, it is approximately -20 minutes, so it is sufficient to add 120 minutes to the sun's visible time.

That is, 13:20 - 20 minutes = 13:00, and it can be easily determined that the current Japan Standard Time is 13:00. You can also use this in reverse.

For example, the current Japan Standard Time is known from a clock, and the visible solar time is determined from the longitude and equation of time correction table 6.

If we adopt the above example, the current Japan Standard Time is 13:00, and from the longitude and equation of time correction table 6, the corrected value is calculated from the longitude and month of the area (in the example, 139°44E in Tokyo is assumed to be the first day of June). - Find 20 minutes. Subtracting this from Japan Standard Time to find the solar time: 13:00 - (-20 minutes) = 13:20
minutes.

Once the visible solar time is determined, by setting the shadow of the shadow bar 6 to 13:20, the accurate direction in that area can be known from the direction display section 401 that is pointing at that time. That is, the sundial 1 can also be used as a compass.

Next, another function of the sundial 1 of this embodiment is the function of knowing the declination of the sun. This will be explained with reference to FIG.

The display unit 2 shows the declination line 208 from -23.5° to +23.5°.
The range of ° is indicated.

Check which declination line the shadow 603 of the shadow piece 601 of the shadow bar 6 lies on. In Figure 4, it is above +22°, which means that the sun is currently at a declination of +22°, indicating that the summer solstice will soon occur.

By the way, when there is a shadow 606 at the position Oo of the declination line 208, it indicates that the sun is on the celestial equator line 207,
Seasonally, this can be seen to coincide with either the vernal or autumnal equinox. Also, when the sun is above +23.5' of the declination line 208, the sun is at its most northerly position with respect to the earth, indicating the seasonal solstice, and -
When it is 23.5 degrees above the Earth, the sun is at its most southerly position relative to the Earth, which indicates the winter solstice.

In this way, the sun's declination can be determined from the declination line 208 and the shadow 306, and from this the sundial can also be used to determine seasonal changes.

Furthermore, if the sundial of the present application is calibrated based on a combination of the equation of time and changes in the sun's declination, it can be divided into either the seasons from the summer solstice to the winter solstice, or the five seasons from the winter solstice to the summer solstice. If you know, you can make a standard time sundial that can read Japan Standard Time directly. In this case, the time scale will be approximately in the shape of an elongated figure 8, but in order to make it easier to read, projection scales may be provided separately for each of the above two conditions. If you make it from paper, you can create an easy-to-read standard time sundial that can be used all year round by putting the above two conditions on both sides and assembling it in the opposite way.

Furthermore, as a way of marking the scale to correct the equation of time, it is also possible to set a date scale in the longitudinal direction of the shadow bar so that the standard time can be read at the corresponding month and day.

With this application example, a sidereal time and sundial using the sun can also be created.

〔Effect of the invention〕

As described above, the sundial of the present invention is capable of not only knowing the visible solar time of the area, but also being able to know the visible solar time and Japan Standard Time using a correction table, and also has an azimuth indicator. Because it is a small portable type, it is possible to set the sundial accurately, and by adding a latitude adjustment mechanism, it is possible to set the sundial more accurately and also to know the declination of the sun.

Furthermore, the sundial of the present invention can be easily assembled from two sheets of board material, and is particularly effective when used for educational purposes.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the sundial of the present invention, Fig. 2 is a developed view of Fig. 1, Fig. 3 is a plan view of the display section with the time scale enlarged, and Fig. 4 is an enlarged display of declination. A plan view of the section is shown. 1...Sundial, 2...Display section, 6...Shadow bar, 4...Direction indicator 1.5...Pedestal , 201
...Inner circumferential surface, 202...Time scale, 203.204...Cylindrical plane, 207...
...Celestial equator line, 208...Decline, 2.09...Winter solstice line, 210...Summer solstice line, 211.212.213.502...・Latitude line,
601... Shadow piece, 401... Direction display section, 402... Declination angle display section, 502... Installation surface, 6... Latitude and equation of time correction table. Figure ■ Figure Figure 302 Aya 303 Cedar

Claims (3)

[Claims] (1) In a sundial that measures time at the position of the shadow of a ridge line approximately parallel to the earth's axis, there is a display section with a time scale and a substantially cylindrical shape, and a display section located approximately in the center of the cylindrical shape of the display section. A sundial comprising: a shadow rod for creating a shadow; a pedestal for holding the shadow rod and the display section; and a compass arranging section integrally formed with the pedestal. (2) The sundial according to claim 1, characterized in that it has a correction function corresponding to the latitude and longitude of each location. (3) The sundial according to claim 1, wherein the display section, the pedestal, and the compass arranging section are drawn on a single plate and assembled by bending the plate.