April 15, 1947. E, HILL 2,418,933 NAWIGATIONAL CALCULATING INSTRUMENT Filed Nov. 24, 1945 2 Sheets-Sheet

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ATTOINEY Patented Apr. 15, 1947 2,418,933

UNITED STATES ATENT OFFICE 2,418,933 NAWGASIONAL CA, CULATING NSTRUMENT Ebeneger Hill, Stanford, Conn. Applieation November 24, 1945, Serial No. 630,617 3 Caials. (C. 235-78) 2 The present invention relates to calculating in distance, either expressed in degrees and min. Struments and more particularly to a calculat utes, or in hours and minutes, of a Selected body ing instrument adapted to solve problems of inn away from a given meridian at a given time. I portance in navigation. navigation this quantity is referred to as 't.' In my Patent No. 2,404,709 issued July 23, 1946, The final answer to the calculations is the same of which the present application is a continua Whether the Nautical or the Air Almanac S tion-in-part, a calculating instrument is described used. and claimed by which various navigation problers In the device of my Patent No. 2,404,709, the can be calculated mechanically. By that, instru determination of the hour age is effected i. ment, if any one of the factors, such as date, tine 10 hours and minutes and also in degrees and raisi by chronometer, longitude, name of star, or hour tates; in the device of the present invention the angle of a Star, or of any other body, is unknown answer is determined with equal facility azadi and the other factors are known, the unknown. Sinuitaineously both in terms of arc and in tei"Ins factor can be calculated accurately and guickly. of time. Navigators either at Sea, or in the air depend In the simpler form of the present invention the either on the Nautical Almanac or the Air Al data employed is derived from the Air Algaria.c manac, for the data, from which these coinpu which, as previously stated, is expressed in terns tations are derived. The two almanacs, however, of arc. The answer, however, is given both in differ since the Nautical Almanac gives its data: teins of arc and in tellins of title: in other Words, in terms of time and in arc which, however, is 20 there is an automatic conversion fron ters of subject to many corrections, whereas the Air arc to terins of time in the result attailed. Almanac gives its data in terms of arc with all in the more complete form the data, eiiployed corrections having been made for every ten min may be derived either from the Nautical Almanac utes of each day of the year. or the Air Almanac and, regardless of which data, The instrument of my said cope:ding applica is used, the result obtained by use of this institu tion is more Suitable for use with the data, derived rent will be expressed simultaneously both in from the Nautical Arnainac than it is with the terms of arc and in terms of time. data derived from the Air Almanac, arid, while it, The invention will be more fully understood can be used with the latter, there is much more from the drawings in which Fig. 1 is a form of likelihood of confusion due to the necessity of the invention adapted for use with data delived converting from terms of arc to terms of time. from the Air Almanac; Fig. 2 is a fragmentary It is an object of the present invention to pro sectional elevation of Fig. 1 taken aiding the vide a calculating instrument of the general type ineridian line of the handle of Fig. 1; iig. 3 is 2, disclosed in my said copending application but form of the invention adapted for use either Wit. adapted for use specifically with the Air Almanac. data, derived from the Nautical Almanac or data, However, with this device the same difficulty will derived fron the Air Amanac; and Fig. 4. is a present itself if it is employed with the Sautical fragmentary sectional elevation of Fig. 3 taken Almanac, in which case it would be necessary to along the meridian line of the handie of that convert from terms of time to terras of arc. figure. Accordingly, it is a further object of the present 40 Referring now to Fig. 1, it will be seen that thie2 invention to provide a combination instiuinent, disks are pivotally mounted so as to be rotatakle which is adaptable for use with either the Air relatively to each other. The top disk i is the Almanac or the Nautical Anana C and Without longitude disk having degrees indicated on the the necessity of converting terms. For instance, margin thereof running fron Zero, indicated o: the most important coinputation constantly used the latter G, which stands for Greenwich, Colin in navigation is the determination of the local terclockwise to 180 and clockwise to 130, in?ii hour angle of a star or the sun, moon or planet cating degrees of longitude east, and west. E. e that is, the hour angle of a particular body cal Secord or middle disk 2 represents the Star hour culated from the particular ineridia (n at which angle. On this disk Zero is indicated by a Sta. ' the ship or airplane may he at any given time. symbol and it bears marginal graduations repre This hour angle is the angle expressed either in senting degrees from zero to 360 counterclockwise. terms of arc or in ters of time between the The third or bottom disk 3 has three Scales. She meridian of longitude of a given place and the inner scale 3d adjacent to disk 2 is the local hou?" meridian through the given body which is used angle scale and is graduated from Zero, iridicated as a basis of reference. It is, in other words, the by L. H. A., to 2 clockwise, and countercioc 2,418,933 3 4. wise east and west. This is a conversion Scale zero, indicated by the letter 't,' clockwise to 180° from arc to time. The middle Scale 35 on disk 3 and also counterclockwise to 180°. Outside this is the 't' scale and is graduated in degrees from Scale and running around the margin of disk f5 zero, indicated by the letter “t,' to 180 clock is the Greenwich hour angle scale on which Zero wise and 180 counterclockWise east and West. is indicated by the letters G. H. A. This scale The Outer Scale 3c of disk 3 is the Green Wich Carries markings indicating degrees running hour angle scale. This is graduated in degrees fron Zero (G. H. A.) to 360 counterclockwise from zero, indicated by the letters G. E. A., to and is marked in a distinguishing color such as 360 counterclockwise. This letter scale can be red On disk 5 the Zeros of the three scales in used for reading the value of 'i' when it is Over dicated by the black star, letter 't' and letters 180° if desired in some calculations. The ZeroS G. H. A., are in alignment. of all three scales of this disk are in alignment. A handle Similar to the handle above described As shown, the three disks are mounted Con in relation to Fig. 1 extends radially from the centrically and pivotally by the gronmet 4 which pivotal grommet which binds the disks concen also pivotally secures the handle 5. This handle trically across the device. This handle has an is preferably made of transparent material and upper arm 6 which carries a meridian line and consists of an arm 5a, which passes above the extends above all the disks. A lower arm T ex disks and arm 5b whlch goes underneath the tends underneath the disks, both being pivotally disks, both being secured at the center by the Secured at the center of the device by the grom grommet 4 and being united at the outer edges 20 met 8 and at the Outer end by the rivets 9. by the rivets 6. A meridian line On the upper When using the Nautical Almanac, disk 4 hav arm 5a, extends radially over the disks from the ing the red star and red degree indications and central grommet 4 to the outer end of the handle the red Outer Scale G. H. A. are not used. The 5. inner scale of disk 5 identified by the black star There are many problems which can be deter at Zero is used as is scale marked 't' and also mined by the instrument of the invention, a few disks , 2 and 3. of Which are the following: When the Air Almanac is used, disk , the (1) To find the local hour angle of a Star. longitude disk, f4 the red star disk and disk 5 (2) To identify a star observed. are used. On disk 5 the red G. H. A. scale, the 30 “t' scale in black and the black star Scale, con (3) To find the local hour angle of the Sun Or a Vert the arc of 't' into time if desired. planet or the moon. To illustrate the use of the instrument shown In each of the above problems the op&rator of in Fig. 3 when using data from the Nautical the instrument is assumed to be using the Air Almanac: Aimanac and deriving his data, therefrom. 35 Calculate the local hour angle, 't,' of any star However, the form of the device shown in Fig. Ol' planet When the date, longitude and chronon 3 may be used with either the Air Almanac or eter tine and the name of Star or planet are the Nautical Almanac. known. With the date and time by chronometer Referring now to Fig. 3 it will be observed that get the right aScension of the mean Sun and also there are five disks of progressively increasing 40 the right ascension of the star or planet from the diameters concentrically and pivotally mounted Nautical Almanac. so that they rotate freely in relation to each other. The top disk l l is the longitude disk and (1) Place the 'G' of the longitude disk, the top is marked with graduations from Zero, indicated disk, On the chronometer time on the sec by the letter G, counterclockwise to 180° and also 45 ond disk, the Sun disk. from zero G clockwise to 180°. At the 180 grad (2) Rotate both disks, the longitude disk and uation a letter X or other symbol is placed. Next the Sun disk, together as one until the zero below the disk is the sun disk 2 on which of the Sun disk registers with the right zero is indicated by the conventional Sun Symbol aScension of the mean Sun on the third and graduations indicating time are placed disk, the Aries disk. thereon running counterclockwise from the Zero (3) Holding these three disks as One, put the (sun symbol) to 24, Below the Sun disk f2 is the meridian line of the handle on the right Aries disk 3 on which zero is marked by the ascension of the star or planet, as given Aries sign and the calibrations run counterclock in the Nautical Almanac, on the inner wise from zero to 24. Next below the Aries disk 5 5 Scale of the lowest disk, the black star is a star disk 4 on which are calibrations indi Scale, cating degrees running from Zero, indicated by (4) Rotate the three top disks together as one the star, counterclockwise to 360°. As indicated, until the sign of Aries is under the merid the star representing Zero on disk 4 is shown ian line of the handle. as of a different color from the preceding disks. (5) Holding all disks in this position, rotate the This star as well as the numerals indicating the handle until the meridian line registers calibrations and the scales themselves, for in with the longitude on the top disk. stance, may be red while the other disks may (6) Read the local hour angle, 't,' under the be printed in black. meridian line of the handle on the middle The lowest disk, indicated by the numeral 5, scale of the lowest disk. has three scales, an inner Scale on which Zero is indicated by a star which, in view of the fact This is in degrees east or west from your local that the star symbol on disk 4 may be assumed meridian and is so marked. If an hourly con to be red, will be black the same as disks , 2 version is desired, read the star scale (black), and S. The star scale on disk 5 represents the 70 the inner Scale Of the lowest disk under the me right ascension of a body and is marked With ridian line of the handle. If above 12 hours, calibrations indicating hours and minutes run Subtract this value from 24 hours. This sub ning from Zero indicated by the star clockwise traction can be easily made on the instrument to 24. A middle scale on disk 5 is marked with by holding the handle and four lower disks as graduations indicating degrees running from 75 one and rotating disk if until the G is under 2,418,933 S 6 the meridian line of the handle, then holding () Put; the meridian line of the inandle on the all disks as one, rotate the handle until the Sun G. E. A. on the oute scale of the low meridian line registers with the Symbol X at 180° est, disk E, the red Scale. Or, in the case from G. The hour or arc is then read directly of a pia.net or the 10On, use the G. H. A. Of under the meridian line On disk 5. that body as shown in the Air Almanac, Calculate the lo3al hour angle, 't,' of the Sun. (2) Fut the 'G' of the icingitude disk under When the tine and the date and the iongitude are the neridian line of the handle. known, Rotate the handle until the aeridiar) line With the date and the time by chronoheter, registers with the Cingitude OIn the Op disk get the right ascension of the mean Sun from the O . Nautical Almanae. (4) Read the middle scale “it’ of the lowest disk (1) Place the point diaInetrically opposite 'G' 5 under the meridian line of the handle (180° marked “X”) of the longitude disk for local hour angle of the Sun or other f on the chronometer time on the Sun disk body. The inner scale on disk 5 converts 2. this into time but if over 12 hours, subtract (2) Hold as one disks and 2 and place the it, from 24 hours as above described. The sun symbol of the sun disk on the right Scale “t’ shows whether the hour angle is ascension of the mean Sun on the Aries east of West from your neiridian, disk 3. iron tile foregoing examples the difference in (3) Hold as one disks i , 2 and 3 and place operation when using the Nautical Amanac and the meridian line of the handle on the the Aii Aihanac will be seen. With the data right ascension of the mean Sun again. On from the Nautical and Air Alina lacS. We arrive the Star right ascension Scale of the OWest at the same result for the local hour angle must disk 5, the black star Scale. be the sale no matter which method We use. (4) Rotate the three top disks , 2 and 3, to Other probiens are worked in much the same way. gether as one until the sign of Allies On All of these on the same instrument, that is, the disk 3 is under the meridian line of the One shown in the Fig. 3 With the five disks. handle. Having this described iny invention, what I (5) Holding all disks in this position, rotate the Cain S: handle until the meridian line registel'S 30 i. A navigational calculating in Struisert COIn with the longitude on the top disk . prising five Superposed disks of diameters pro (6) Read the local hour angle, “t, under the gressively is creasing fron top to bottoil, mount neridian line of the handle on the middle ed rotatably in Irelation to each other. On a rotat scale of the lowest disk 5. This is in de abie handle on a corhinor center; Said topra0St grees east or west from your local merid disk being provided With graduations indicating ian. If an hourly conversion is desired 86° of Ogitude east, and West; Said Second and read the black star Scale of the lowest disk third disis being provided with graduations indi 5 under the meridian line of the handle. cating houl's and rinutes fron Zero to 24 coun If above 12 hours, Subtract this from 24 terclock Wise; Said fourtin disk being provided hours in the manner above described. With graduations indicating degrees of arc from To illustrate the use of the Air Allmanac in SOV Zero to 36 counterclockwise, and Said fifth disk ing these same two problems. The date, time of being provided With three concentric Scales hav day and the name of the star are knoWn. Using ing their Zero pointS in alignment, Said in most this data, get the Greenwich hour angle of Aries Scale having graduations indicating hours and from the Air Almanac and also the Sidereal hour niiutes fron Zero to 24 clockwise, Said middle angle of the Star. Scale having graduations indicating degrees from (1) Put the meridian line of the handle on the Zero to 80° clockwise and fron Zer0 O i80 COun G. H. A. Aries on the outer (red) Scale of tier 3ockwise and Said outeriost Scale having the lowest disk 5. graduations indicating degrees of arc fron Zero (2) Put the star symbol of the star disk 4, the to 360 couintercock Wise; and a meridian line red star scale, under the meridian line of radially disposed acroSS Said diskS on Said handle the handle. and rotatable in relation to Said diskS. (3) Put the meridian line of the handle on the 2. A navigational calculating instrument con S. H. A. of the star on the red star disk f4. 5 5 prising a plurality of rotating disks centrally piv (4) Put the “G' of the longitude disk under oted and Superposed and of progressively increas the meridian line of the handle. ing diameter's and a rotatable handle also pivoted (5) Hold all disks firmly and rotate the handle at the connon cerater of Said disks, Said handle until the meridian line registers With the gearing a neridian line extending radially Over local longitude on the top disk . 60 said disks; scales ari'anged circularly on Said (6) Read the middle scale “i' of the iOWest disk disks indicating the necessary faitors for Calcu 5 under the meridian line of the handle. lating navigational problems including 180 de This is the local hour angle of the Star in grees of longitude east, and West, tire by chro degrees east or west of your local meridian. In Ometer encorp2.SSing tWenty-four hours coun If conversion to hours is desired, read the terclockWise, right, aScension of the nean Sun en blask star scale of the inner Scale of this compassing tWenty-four hours counterclockwise, lowest disk 5. If this is Over i2 hourS, right ascension. Of a Star, planet or moon era COn subtract it from 24 houl'S in the nanner passing twenty-four hours clockwise, neridian above described. angle scale indigating 180 degrees of arc east and To find the local hour angle of the Suth Ol' planet O West, Greenwich hour angle scale in degrees of or the moon. The date and the time of day and arc counterclock Wise, and sidereal hor ange the longitude are known. Get from the Air Al Scale in degrees of arc counterclockWise. manac the Greenwich hour angle of the Sun or 3. A navigational calculating instrument cOn the planet or the moon for the date and time of prising three Superposed disks centrally pivoted day. 5 and of progressively increasing diameters from 2,418,933 7 8 top to bottom rotatable about the common cen ter; Said diskS bearing graduations disposed cir REFERENCES CTED cularly thereon and indicating navigational in The following references are of record in the dicia including degrees of longitude east and file of this patent: West, degrees of arc from Zero to 360° in counter clockwise direction, Calibrations in terms of time UNITED STATES PATENTS encompaSSing tWenty-four hours, degrees of arc Number Name Date 180° clockwise and 180° counterclockwise and de 1,145,020 Hill ------July 6, 1915 grees of arc from zero to 360 counterclockwise; 1,207,439 Picolet ------Dec. 5, 1916 and a rotatable meridian line on a handle pivot 10 2394,226 Boldocchi ------Feb. 5, 1946 ed centrally of said disks and extending radially 2,404,709 Hill ------July 23, 1946 aCrOSS Said disks. EBENEZER. H.