US 1161381 A
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c. H; DUFFY. CALCULATOR.
APPLICATION FILED MARI9. 1915-.4
Patentedv Nov. 23, 1915.
COLUMBIA PLANouR/PH fo., wAsHlNuTuN. D. C.
-U'Nirnn sTATEs" rATENT onirica.
CHARLES HUGH-DUFFY, OF CHEVY CHASE, MARYLAND.
To all 'whom it may concern lBe it known that I, CHARLES HUGH DUFFY, a citizen of the United-States, re-
siding lat Chevy Chase, in the county ofV Montgomery and Statevof Maryland, haveA invented certainrnewand useful Improvements in Calculators; and I do declare the following to be'a full, clear, and eXact devio scription ofthe invention, such as will enable others skilled in the art to which it appertains toY make and use thehsame, reference being had to the accompanying drawings, and 4to the letters and-figuresof ref-v erence markedthereom `which form a part of this specification.
This invention relates-to the class of calculators but more particularly to a device for adding, subtracting, dividing and multiplying two figures, the same'beingk arranged in such manner that the sum, the
' difference, the result` and the quotient of the addition, subtraction, multiplication and division of two numbers will be simultaneously indicated. Y Y c -The invention consists in the arrangement of two disksl pivoted centrally so as to be Y capable. of relative rotation, the under disk having thereon marginal numbers spaced one from the other rand having opposite each marginal number the sums, the differences, the results and the quotients of said number and any other marginal number appearing on the upper disk, the said upper ldisk being provided with marginal numbers VLike numerals of'reference indicate the same parts throughout the three figures.
For a morey ready and simple illustration of this invention the device illustrated in the accompanying drawing has been limited to Figs. l to 5, as the same is clearly sufficient to illustrate the construction and principle ofthe invention `and any additional iigureswould unduly complicate they illusrSpecification of Le'ttersrPatent.
Patented Nov. 23, 1915.
Application filed March 9, 1915.; Serial No. 13,175.
tration,yandj would add nothing to a clear -1 understanding of the invention. it is-.to be clearly understood that the marginal numbers on the disks can run from l to Aanydesired number, the only limit being Although i the size of the disks, and inY practice it is desired to include on the disks marginal numbersrunning higher than those shown lin the accompanying drawing.
Referring to the drawing by reference numerals 1 indicates the device comprising the lower disk 2 and the upper disk 3f pivoted centrally at 4 in the manner as shown in F ig, 3.l The lower disk.2 is preferably largerl in diameter than the upper disk 8, sol that the large Vmarginalnumbers 'may be displayed thereon, although this construction is not entirely essential as the marginal numbers 5 on the lower disk may be placedimmediately around the pivotal point thereof, while the marginal numbers 6 on c theupper disk may be similarly disposed.
Vadjacent the pivotal point.
c In this event thetwo disks 2 and 3 could be of equal diameter. From this it will be understood that the marginal numbers hereinbefore and hereinafter mentioned may be disposed on the disks in the most convenient manner,
so long Aas they are visible and can be brought opposite.
The disk2 having the marginal numbers 5 is preferably provided withk a series yof marks 7 while the upper disk 3 is preferably provided withv a series of marks 8,-
whicli marks on said disks Vshould register in the manner as shown in Fig. l inorder to insure the proper position of the upper disk in relation to the" lower disk when any of the marginal numbers on the said disks are brought opposite to each other for the puri' pose of indicating the sum, the difference, the result and the quotient of the said two numbers, saidseries of numbers being indicated by the numeral 5.
The marginal numbers on. the upper disk are preferably providedwith the usual arithmetical signs .9 and the equal marks 10 and lines 11 passing therefrom to the openings 12 in the disk 3, so that the numbers on the lower disk visible through the openings l2 are quickly connected by the eye with the marginal numbers on the upper disk lin the manner as illustrated in Fig. l.
Having thus described the invention it will be noted `from Fig. l that the openings 12 on the disk 3 are differently located in said disk for each marginal number thereon, said openings on said upper disk corresponding with the numbers appearing on the lower disk which are the sums, the differences, the results and the quotients of any of said marginal numbers on the lower disk with respect to any and all of the said numbers on the said upper disk in such manner that the openings on the said upper disk which are opposite a certain marginal number thereon will always uncover certain numbers on the lower disk arranged at a certain predetermined point on the lower disk, in the manner as will be clearly apparent upon inspection of the accompanying drawing.
I lay no claim whatever to a calculating device in which only a single factor of two given numbers is indicated or uncovered by the calculator, as such a device is not within the spirit of this invention, which is primarily designed as a mathematical educational device wherein a plurality of factors of two given numbers are simultaneously displayed or indicated.
Having thus fully described the invention what I claim as new and desire to secure by Letters Patent of the United States is l. A calculator of the type described including two relatively rotatablel disks centrally pivoted, the lower disk containing a series of marginal numbers, the upper disk containing a series of marginal numbers, the lower disk containing opposite each marginal number thereof the sums, the differences, the products and the quotients of said marginal number with respect to every marginal number appearing on the upper disk, the said upper disk being provided with an opening opposite each marginal number thereon and in line with the numbers on the lower disk constituting the sum, the differ ence, the product and the quotient of said marginal number on the upper disk with respect to a marginal number on the lower disk, to simultaneously indicate the sum, the dilference, the product and the quotient of any two marginal numbers upon a single relative movement 0f the disks, the said opening opposite each marginal number on the upper disk being disposed in a different position from the other openings therein substantially as described and for the purposes set forth.
2. A calculator of the character described including a lower disk having marginal numbers thereon, an upper disk pivoted thereto and having' marginal numbers thereon, the lower disk being provided opposite each marginal number thereon with a plurality of series of numbers, the same being the factors of said marginal number with respect to all of the marginal numbers on the Lipper' disk, the said upper disk being provided with an opening opposite each marginal number thereon and in line with the numbers on the lower disk corresponding with the factors of said marginal number in connection with all of the marginal nun1- bers on the lower disk to simultaneously uncover a number of each plurality of series of numbers on the lower disk opposite a marginal number thereon upon a single relative movement of the disks, the said opening in said upper disk opposite each marginal number thereon being disposed in said upper disk at a diiferent point from the other openings therein substantially as described.
3. A calculator' of the character described including a lower disk and an upper disk pivoted together, each of said disks being provided with marginal numbers adapted t0 be brought opposite to each other upon relative rotation of the said disks, the said lower disk containing opposite each marginal number thereon a plurality of series of numbers, each series of numbers being the results or factors of said marginal number in connection with all of the marginal numbers on the ripper disk, the said upper disk being provided with an opening therein opposite each marginal number thereon to uncover a numer in each of said plurality of series of numbers opposite each of the marginal numbers on said lower disk to simultaneously indicate a plurality of results or factors of any marginal. number on the upper disk in connection with any marginal number on the lower disk upon a single relative movement of the disks, substantially as described and for the purposes set forth.
In testimony whereof, I afx my signature, in presence of two witnesses.
CHARLES HUGH DUFFY. l/Vitnesses:
REID STANTON, MARGARET SHAW.
Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.