International chronometer

Dec. 30, 1941

2,268,239

A. M. BRAATEN

INTERNATIONAL CHRONOMETER

Filed Feb. 23, 1938 2 Sheets-Sheet 1

<img file="US2268239A_D0001.tif" />

<img file="US2268239A_D0002.tif" />

BY

<img file="US2268239A_D0003.tif" />

INVENTOR.

M. BRAATEN attorney.

Dec. 30, 1941.

A. M. BRAATEN

INTERNATIONAL CHRONOMETER Filed Feb. 23, 1938

2,268,239

Sheets-Sheet 2

<img file="US2268239A_D0004.tif" />

<img file="US2268239A_D0005.tif" />

<img file="US2268239A_D0006.tif" />

<img file="US2268239A_D0007.tif" />

INVENTOR.

BY

ATTORNEY.

Patented Dec. 30, 1941

2,268,239

UNITED STATES PATENT OFFICE

2,268,239

INTERNATIONAL CHRONOMETER

Arthur M. Braaten, Riverhead, N. Y., assignor to Radio Corporation of America, a corporation of Delaware

Application February 23,1938, Serial No. 191,864 (CL 58—43) curate and useful means of determining the time In any part of the world.

The present Invention may best be described by reference to the accompanying drawings, which shows one specific embodiment of the same.

Referring now to the drawings, Fig. 1 is a front elevation showing the chronometer face;

Fig. 2 Is a section taken on line 2—2 of ng. 1;

Fig. 3 is a partial front elevation showing another embodiment;

ng. 4 is a partial section of ng. 3;

Fig. 5 is a partial section of a further embodiment;

ng. 6 is a detail section showing a modification of Figs. 4 and 5; and ng. 7 is a detail section showing another modification of Figs. 4 and 5.

Referring now to ngs. 1 and 2 of the drawings, i is a stationary, twenty-four hour time dial and Is to be used in connection with a timepiece having a twenty-four hour movement. This dial is suitably marked to indicate the hours 1 to 12 a. m. and also 1 to 12 p. m. Extending over to the face of dial I are hour hand 4 and minute hand 5. The li tter hand extends slightly beyond the hour hand. Both hands are operated by any suitable time clock mechanism 6. Hands 4 and 5 are arranged to Indicate on dial I the local time

Located within dial I is a ring-like disc or annulus 2 which may be rotated about an axis passing through its center, by any suitable manual means, such as for example, a finger engaging

Greenwich mean time and is arranged so that it can be manually set to show the G. Μ. T. corresponding to the local time at any given place. _ Within the center of the chronometer there is with hour hand 4 and is equipped with a disclike clamp or friction clutch 8 which, by means of a plurality of spring members 9, applies through a plurality of fingers 10 friction, so as

- - ” The lower end of fingers 10 are retained in place by means of nuts II. A depressed finger engaging portion 7 α is provided preferably on the outside of dial 3, so as to allow its being set manually in any desired position with respect to hour hand 4. The face of dial 3 is laid out in sections corresponding to the international time zones, each section covering fifteen degrees of longitude. In the center of the disc 3, sections are marked in

Claims.

This invention relates to the art of reckoning time and deals more specifically with a chronome? ter or international time clock which gives the standard time in any part of the world. The dial and the mechanism of the clock are so arranged as to show directly standard time and Greenwich mean time in any part of the world, and also the local time of the place at which the clock is located.

An object of this invention is to simplify and improve chronometers, so that in addition to the local time, a direct reading of standard time and Greenwich mean time in any part of the world may be readily obtained.

Another object of this Invention is to provide an Improved chronometer with a twenty-four hour movement and to associate therewith a rotating geographical scale and a rotatable scale indicating Greenwich mean time.

Because of the rotation of the earth on its 20 axis from west to east, sunrise takes place at any given point earlier than at a place to the west of that point. This means that all places east of a given meridian are ahead in time, while those west are behind. Since the earth makes 25 one complete rotation in twenty-four hours, it takes exactly one hour for the sun to make a transit across the space between the meridians ^{by fiiteen degrees} to ------------------------------longitude. By international agreement, the world ³⁰ at any place at which the timepiece is to be used has been divided into time zones, each fifteen I ........ ’ degrees of longitude in width. The time in each zone is the same as that of the meridian passing through Its center, and the times in adjacent ______________ zones differ by one hour. All time is reckoned ³⁵ depressed portion 7. Ring 2 is marked to show from the prime meridian of Greenwich, the time ' on that meridian being termed Greenwich mean time, or G. Μ. T. Most of the countries of the world follow the international time system, but --------------- -------a few use the local time of some important city. ⁴⁰ located a movable disc 3 which normally travels

Heretofore, in order to determine the time at ^J ' any place in relation to the time at any other place, it has been necessary to consult tables or make use of conversion charts. This procedure 45 _to engaae’thPunXidX «7X1 Γ is both inconvenient and unsatisfactory, because -- di 1 3.

of the time required in making the conversions and the great possibility of making errors. Since it is desirable to be able to determine accurately the time in any part of the world with the least 50 amount of effort, the present invention was brought forth to give this time directly from the dial, thus doing away with the necessity of using tables and conversion charts. It is therefore an ____ _______ „ ________ „_xc ,_n object of this invention to provide a more ac- 55 the degrees'longitude, ^''and'irest “f*Green^

2,268,239 being the same all over the world. At the same time it is 1:00 a. m. in Alaska, noon in middle Europe, 4:30 p. m. in India, 8:00 p. m. in Japan, 8:30 p. m. in central Australia, and 10:30 p. m. in New Zealand. While it is 11:30 p. m. of a certain day in British Samoa, it is 10:30 p. m. of the new day in New Zealand as the international date line is situated between these two countries. This is because Samoa lies between the 180th meridian and midnight on the clock dial. In crossing the 180th meridian, the international date line, from east longitude to west longitude, a day is lost; in crossing from the opposite direction, a day is gained. When the midnight line is passed by the pointer on the dial, there is, of course, also a change in the date. In going around the dial clockwise, it is one date from the 180th meridian to midnight, and another date, or the following day, for the rest of the way around the dial.

Furthermore, in Fig. 1 of the drawings, only one-hour divisions are shown on disc I. It should be understood, however, that divisions of one minute could be used on the dial. Of course, on a larger disc 3, more countries could be indicated in the various zones. Countries differing from standard time could be indicated thus “Algeria, —9 minutes.” If it were desired to indicate only the more important countries in the various zones, the clock could be arranged to indicate the time in all countries as follows. The Hydrographic Office of the United States Navy publishes a map showing the time zones in colors. All countries in the same zone using standard time are uniform in color.- Those countries using local time are colored differently and the amount of departure from standard time is indicated with the name of. the country. The various sections on disc 3 of the present invention could be colored to correspond to the time zones on the map which they represent. It can be seen that this would make an exceedingly useful

While only one embodiment of this invention has been described; it· is to be distinctly under10

3a wich, of the meridians of the time zones. In each section are indicated the principal country, or countries, of the corresponding time zone. Since some countries use a time which differs from standard time by one-half hour, these countries are indicated on the movable disc 3 as being small sections formed from an equal portion of each of two adjacent standard time hour sec· tions. For protection against dust, moisture, etc. the entire mechanism is preferably enclosed with- , in a suitable casing 12 with a glass face 13.

The embodiment shown by Figs. 3 and 4 is in general similar to Figs. 1 and 2, except that dial 3 is positively secured to the hour hand 4 by means of a threaded pin .14 and washer 15, the dial 3 having located on its surface twenty-four holes equally spaced in the center of each hour section to receive pin 14. This arrangement does away with the friction drive or clutch 8 and its. associated elements 9, 10, II. Ring 2 is supported by means of a plurality of equally spaced posts 16 which support a track 17. The underside of ring 2 has spring clips 18 that grip in frictional engagement track 17, ring I being fixed to the casing 12b by any suitable means.

The other embodiment shown by Fig. 5 is similar to Fig. 4, except that the rings I and 2 are reversed in position, that is, ring 2α is outside and ring la inside, a plurality of spacers 20 and 21 securing ring la to case 12α by means of screws 22 and 23. Post 16α is supported by a strip 24.

The modifications to the dials shown by Figs. 6 and 7 comprise a one piece disc 25 pivoted to the hub of clock mechanism 6 to which a ringlike dial 2b is secured for rotation and retained by any suitable means, such as a lip 26, cut and bent over from the metal of disc 25. The cuter rim portion of disc 25 and dial 2b is marked and functions similar to members I and 2, respec- 40 tively, of Fig. 1. Fig. 7 shows a ring-like dial 2c located at the outside rim portion of a member 25α and secured thereto by a screw 27. The dial 25α is provided with twenty-four holes located in the center of each hour section for securing dial 2c and member 25α in a desired position. Just within the inside diameter of ring-like dial 2c, disc 25α has a step-like raised portion to provide a dial surface which will lie in the same plane as the surface of dial 2c. The raised portion I c of member 25α and ring-like dial 2c is marked and functions similar to members I and 2, respectively, of Fig. 1.

The operation of the device is as follows:

The clock is first set so as to indicate on dial I the local time of the place at which it is to be used. Then disc 2 is turned until the hands also indicate the G. Μ. T. of said place, at which setting it is allowed to remain. Now, disc 3 is rotated until the time zone corresponding to the _ location of the clock is opposite the local time reading. It is then maintained at this setting and travels with the hour hand. The clock will now correctly indicate the following: local time of the place at which it is located, the G. Μ. T. corresponding to this local tune (which is, of course, the same for the whole world), and the ——,— .,.-.—_ —.._ standard time of any country using standard means to move said third, dial, 'said third dial artime. The extreme usefulness of such a device ........,., .

will be readily apparent.

The drawing, as shown by Fig. 1, has been laid ,------...--------- __ ____ _ _ out to show how the elock dial would be set for third dials to indicate a desired time on said any location using Eastern Standard Time. stationary dial.

When it is 6:00 a. in. in New York, the corre- 2. A chronometer adapted· to indicate the spending G. Μ. T. is 11:00, the G. Μ. T. of course 75 standard and Greenwich mean time of different arrangement.

stood that it will not be limited to the type shown, but should only be limited to such limitations as are clearly imposed in the appended claims.