JPS6288983A - Timepiece with twilight display - Google Patents

Abstract

PURPOSE:To provide a twilight display function to a timepiece by displaying a sun position on a display plate which makes one turn in one sidereal day and displaying the horizontal and twilight threshold line on a dial or windshield disposed in superposition on the display plate. CONSTITUTION:A constellation display window 6b and a twilight discrimination window 6c for seeing through of a constellation display plate 2 are provided. The 1st constellation display part 7 is constituted of the constellation display window 6b, the twilight discrimination window 6c and the constellation display plate 2. The window 6c is enclosed of an arc 6g, an arc 6h and an arc-shaped curve 6i indicating the astronomical twilight threshold line, and is so constituted as to indicate the state in which it is not twilight by the sun if the sun position corresponding to the date on the ecliptic 2b drawn on the display plate 2 disposed in superposition under the dial 6 is within the window 6c, the daytime state if said position is within the window 6b, and the state under the twilight if the position is concealed under the dial 6. The twilight state is thus exactly discriminated by the simple wheel train constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a timepiece with a twilight display function.

[Conventional technology]

Even when the sun is setting, the so-called astronomical twilight, in which the sky is not completely dark due to sunlight reflected and scattered by the Earth's upper atmosphere, is not suitable for observing dark celestial bodies. However, during the normal twilight period, which corresponds to just after sunset or just before sunrise, when the sky is relatively bright, some outdoor activities are possible without special lighting.

If a watch were equipped with the above-mentioned function to determine the twilight state as an additional function, it would be very convenient not only for astronomical observation but also for everyday life. There wasn't.

[Problem that the invention seeks to solve]

The brightest planet can be seen when the sun sets 6.5 degrees below the horizon, and when it reaches 186 degrees below the horizon, the sky becomes completely dark. With the above state as a boundary condition, the period when the sun is between the horizon and 6.5 degrees below the horizon is called normal twilight, and the period when the sun is between the horizon and 18 degrees below the horizon is called astronomical twilight. Without knowing the exact positional relationship between the sun and the sun, it is impossible to identify the twilight state. To determine whether or not it is twilight, you need the latitude of the point, the local sidereal time, and the accurate position of the sun on the celestial sphere (right ascension and declination). The speed of the sun's movement is not constant because the Earth's orbit is elliptical, and the ecliptic intersects the celestial equator at an angle of about 23.5 degrees, and the sun's declination also changes seasonally. Simply displaying the hand with constant movement of once a day does not allow accurate display of the sun's position on the celestial sphere, and therefore also makes it impossible to accurately determine the twilight state. An object of the present invention is to provide a timepiece having a function of accurately determining the above-mentioned twilight state with a simple wheel train configuration.

[Means for solving problems]

The present invention was made in order to solve the above problems, and the hour hand which holds the hour hand is connected to the hour hand through an adjustment wheel to
Using a watch with a rotating display board, the position of the sun is substantially displayed on the display board by printing or the like, and the horizon and the twilight limit line are displayed on the dial or windshield placed over the display board. is displayed with a hole or printed, and the twilight state can be detected with a simple gear train configuration by the overlapping state of the sun position displayed on the display board and the horizon and twilight limit line provided on the dial or windshield. It is possible to obtain a watch with a twilight display that allows accurate discrimination.

〔Example〕

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

FIG. 1 is a plan view of a twilight display timepiece having a constellation display function according to the present invention, FIG. 2 is a sectional view showing the main parts of the gear train mechanism of the timepiece shown in FIG. 1. FIG. 4 is a plan view of a constellation display board that displays the sun position and constellations of the clock in FIG. 1. FIG. FIG. 2 is a bottom view of the timepiece shown in the figure, viewed from the back cover side.

In the figure, 1 is a clock with a twilight display, 2 is a constellation display board, and 6 is a clock with a twilight display.
is the hour hand that displays the time, 4 is the minute hand, and 5 is the second hand. Reference numeral 6 denotes a dial plate, which has a 12-hour scale 6a at a position corresponding to the hour hand B, and a constellation display window 6 for seeing through the constellation display board 2.
b and a twilight identification window 6C are provided, and the first constellation display section 7 is constituted by the constellation display window 6b, the twilight identification window 6C, and the constellation display board 2. In the first constellation display section 7, the constellation display window 6b is formed by an arc 6d indicating the declination +35°, which is the northern limit of the constellation display in the first constellation display section 7, and an arc-shaped curve indicating the horizon 6e at 35° north latitude. On the dial 6 surrounded by a curved line showing the horizon 6e, NE and E indicating directions are displayed.

S E, S, SW, W, NW letters 6f are drawn.

The constellation display board 2 shows a declination of -55,6' south of the zenith at 35° north latitude, taking into account horizontal refraction of 0.6° due to atmospheric differences.
The main bright stars 2a, the ecliptic 2b, and the Milky Way 2c are drawn from the rotation center of the constellation display board 2 to +35'' at equal declination intervals toward the outer circumference. has numbers 2d from O to 23 indicating the time of right ascension on the outer periphery, and dashed lines at 36 locations on the ecliptic 2b indicating the sun's position at noon on the 1st, 11th, and 21st of each month (at the time of the Japanese symbol) on average. Furthermore, within the cut 2e, near the position of the 1st of each month, month numbers 2f from 1 to 12 indicating the corresponding month are drawn, and the dial 6 is displayed in the south-central direction. The sidereal time can be determined by reading the right ascension value corresponding to the 12 o'clock position mark 6a', and the position of the sun on the celestial sphere can also be determined by reading the position of the sun on the ecliptic 2d corresponding to the month and day. has been done.

The twilight identification window 6C includes an arc 6g indicating a declination of +35°, an arc 6h indicating a declination of -55,6°, and an arc-shaped curve 61 indicating the astronomical twilight limit line with a zenith distance of 108° at 35° north latitude.
If the sun position corresponding to the month and day on the ecliptic 2b drawn on the constellation display board 2, which is surrounded by It is configured so that if twilight is not occurring, if it is within the constellation display window 6b, it is daytime, and if it is hidden under the dial 6, it is twilight. 8 is a second constellation display section drawn on the camera back 9, and the second constellation display section 8 has a declination +35 which is not displayed on the first constellation display section 7 in the center.
The main bright stars 9a and the Milky Way 9b from ° to the celestial north pole are drawn with the celestial north pole at equal intervals in declination, and numbers from O to 21 indicating the time of right ascension are written inside the outer periphery. They are drawn at 45° intervals on the right ascension display section 9c, and the first constellation display section 7
It is configured so that the arrangement of the northern constellations can be known by rotating and viewing the twilight display clock 1 so that the right ascension numeral 9c corresponding to the sidereal time read at the top is on the top. A month/day scale 9d is engraved on the part to correspond to the right ascension numeral 9c, indicating the sidereal time at noon of the average year at the time and longitude lines of the Japanese mark (135 east longitudes).

Next, the wheel train of the timepiece of this embodiment will be explained.

In the figure, 10 is the fourth wheel to which the second hand 5 is attached, 11 is the center wheel to which the minute hand 4 is attached, and 12 is the hour wheel to which the hour hand 6 is attached. 1
6 is the Hinura car, the center car is 110 minutes, the kana 11a and the hour wheel 12.
The hour wheel 12 is meshed with the cylindrical gear 12a of the cylindrical gear 1.
2a and an hour wheel pinion 12b.

Further, 14 is an adjustment wheel, which includes an adjustment gear 14a and an adjustment wheel pinion 14.
The adjustment gear 1 is constructed of an adjustment wheel pin 16 fixed to the main plate 15Vc, is vertically held by the back plate 17, and meshes with the hour wheel pinion 12b.
4a and the adjustment wheel pinion 14b that meshes with the constellation gear 18 is provided with a slip function portion 14c that slips under a load of a predetermined torque or more.

The constellation gear 18 has the constellation display plate 2 fixed to its side end and is loosely engaged with the hour wheel 12, and is connected to the back plate 17 and the constellation display plate dust 1.
It is sandwiched between 9 and 9 including tarte oysters.

Further, the hour wheel 11 is vertically held between a main plate 15 and a back plate 17 along with a dial washer 20 for eliminating the influence of backlash of the wheel train. Reference numeral 21 denotes a correction intermediary wheel, which is composed of a correction intermediary gear 21a that meshes with the constellation gear 18 and a correction intermediary pinion 21b that meshes with the correction wheel 22, and is loosely engaged with a correction intermediary wheel pin 23 fixed to the main plate 15, and is connected to the back plate. 17 holds the vertical position, and the rotational movement from the crown 24 to the correction wheel 22 by the winding stem 25 is not transmitted through idling at the normal position 24a, but is transmitted integrally with the winding stem at the first pull position 24b. Since the engagement with the correction wheel 22 is released in the second pull position 24c, the rotational movement of the crown 24 is transmitted to the correction intermediary wheel 21 via the correction wheel 22 only in the first pull position 24b. It is configured.

Next, the operation will be explained.

The reduction ratio from the fourth wheel 10 to the minute pinion 11a is set to <1/60, as is well known, and from the minute pinion 11a to the minute pinion 13.
By setting the reduction ratio to the hour wheel 12 via the 1/12, the hour wheel 12 rotates once every 12 hours.

One average sidereal day, or the average rotation period of the earth relative to the vernal equinox, is 23 hours, 56 minutes, and 4.091 seconds at average solar time.
In order to match the rotational speed of the constellation display plate 2 to the apparent average motion speed of the stars, the constellation gear 18 is rotated every day (24 hours/2 hours).
3 hours 56 minutes 4.091 seconds) rotation or 1.0027
It is necessary to configure the number of teeth in the gear train from the hour wheel 12 to the constellation gear 18 so that the value is very close to 379 rotations. The combination of the number of teeth with the best approximate accuracy in the range of 12 to 73 teeth is the hour wheel pinion 12b on the drive side and the adjustment pinion 14.
The number of teeth of b is 3N and 61, and the adjustment gear 14 is the driven side.
a and the number of teeth of the constellation gear 18 are 5N and 73 (N is an integer between 4 and 14), and in this case, the constellation gear 18 rotates 1.0027397 times a day, and the annual cumulative error of the constellation display board 2 is This is only a 0.2 degree advance relative to the apparent average motion of the star. The reason why the hour wheel 12 is made of a combination hour wheel composed of the hour wheel pinion 12a and the hour wheel pinion 12b is that the number of teeth of the hour wheel pinion 12b can be selected without being constrained by the meshing conditions with the hour wheel pinion 16. It is from.

Furthermore, by interposing the adjustment wheel 14 between the hour wheel 12 and the constellation gear 18, the direction of rotation of the constellation display plate 2 fixed to the constellation gear 18 is the same clockwise rotation as the hour hand 6 attached to the hour wheel 12. , which corresponds to the rotation condition of the constellation display board 2 in which the declination increases from the rotation center toward the outer circumference.

The operation at the time of initial alignment will be explained below.

First, pull out the crown 24 from the normal position 24a to the second pull position 24c, set the hour hand 3 and minute hand 4 to noon, and then perform longitude and time difference correction. Since the time is early, I set hour hand 3 and minute hand 4 at 11:41 a.m.

Next, read the right ascension value in the right ascension numeral section 9C that corresponds to the month and day scale 9d on the second constellation display section 8. For example, in the case of August 30th, the sidereal time at 135° east longitude and average midday is approximately 10.
It should be 32 minutes past the hour.

Next, pull the crown 24 to the first position, and rotate the crown 24 forward or backward to see the red value of the constellation display plate 2 corresponding to the 12 o'clock position mark 6a' indicating the south-center direction of the dial 6 shown in FIG. is made to match the above value, for example, 10:32 in the case of August 30th.

Finally, pull out the crown 24 again to the second pull position 24c, rotate the crown 24 forward and backward to align the hour hand 3 and minute hand 4, then push in the IJ use 24 to start the second hand 5, and the hour hand 6. , minute hand 4 and second hand 5 to the current time (
(average solar time). For example, as shown in Figure 1, 84
Tokyo at 10:09:39 a.m. on the 30th (longitude correction time difference +1
9 minutes), the local sidereal time after adjustment should be approximately 9 o'clock.

Furthermore, in this embodiment, by using the correction function of the constellation display plate 2 at the first pull position 24b of the crown 24, in the case of the basic latitude (35° north latitude), the current sidereal time in the daytime and the sidereal time in the sunset state are adjusted. If you read the time difference between
Also, if you read the sidereal time difference from the sunrise state to the sunset state, you can read the daylight hours, and after sunset, you can read the time difference between the sidereal time when the sun position passes the horizon 6e and the sidereal time when the sun position passes the twilight limit line 61. The configuration is such that even if the twilight duration time deviates from the above-mentioned degrees Celsius, the hour hand 6, minute hand 4, and second hand 5 can be read without stopping.

In addition, in this example, the latitude used was 35°N, and the celestial sphere was arranged so that the declination of the constellation display board increased from the center of rotation toward the outer periphery, but an idler was installed between the gear train from the hour wheel to the constellation gear. In addition, the direction of rotation of the constellation display board can be made counterclockwise, and the center of rotation of the constellation display board can be set to the north celestial pole. Also, the celestial sphere arrangement conditions of the constellation display board can be changed in specifications at different latitudes including the southern hemisphere. It is clear that the same effect can be obtained by setting the rotational direction conditions, the horizon shape of the dial plate, and the twilight limit line shape so as to match the specifications.

Furthermore, in the embodiment, the sun's position is printed on the constellation display board so that it can be read in correspondence with the month and day, but other methods of actually indicating the position, such as one revolution per day concentric with the hour wheel, etc. If you install a speed guide hand and print line segments connecting the tip of the guide hand and the exact position of the sun on the constellation display board at appropriate intervals,
Even when you don't know the month and day of the day, you can know the sun's position, and if the sun's position corresponding to the month and day is marked on the ecliptic on the constellation display board, you can also read the month and day, so you can use it as an annual calendar. It is also conceivable that the clock can be modified to use a 24-hour clock with an hour hand that rotates once a day. In addition, in this embodiment, since the dial has two large display windows, the constellation display window and the twilight identification window, the exposed area of the constellation display board is large, and a clock with a twilight display function that is beautiful in design can be obtained. .

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a timepiece with a twilight display that can accurately determine the twilight state with a simple wheel train configuration can be obtained, and by providing a slip function section on the adjustment wheel, the time display (average You can also read the twilight duration, sunshine duration, and remaining sunshine duration without stopping the solar time.
It is possible to realize a convenient clock that can be used not only for astronomical observation, but also for outdoor sports such as mountain climbing, and as a time guide for agricultural work, etc., and can be used widely in daily life.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is a plan view of a timepiece with a twilight display, FIG. FIG. 3 is a partial plan view schematically showing the wheel train of the timepiece with a twilight display, FIG. 4 is a plan view of a constellation display board, and FIG. 5 is a bottom view of the timepiece with a twilight display. 2...Constellation display board, 2b...Ecliptic, 2
e・・・・・・Cut indicating the position of the sun on the ecliptic, 2f・
...Indicates the position of the sun at the beginning of the bow month on the ecliptic, letter I, 3...Hour hand, 6
...Dial board, 6c... Twilight identification window, 6
e...Horizon, 61...Twilight limit line,
12... Hour wheel, 14... Adjustment wheel, 18
...Constellation gear. Patent applicant Citizen Watch Co., Ltd., I, 1.7 Usoku @
Figure 1 Figure 3

Claims (1)

[Claims] In a clock having a display plate that rotates once per sidereal day from an hour wheel holding an hour hand via an adjustment wheel, the position of the sun is substantially displayed on the display plate, and the display plate is arranged so as to overlap the display plate. A timepiece with a twilight display characterized by displaying the horizon line and the twilight limit line by holes or printing on the dial or windshield.