US1084254A - Interest-computing machine. - Google Patents

Description

J. A. GASHBL. INTEREST COMPUTING MACHINE. APPLIOATION PIL'ED MAYZ, 1912y Patented Jan. 13, 1914,

2 SHEETS-SHEET l.

lill-1:21

IETEREST COMPUTING MACHINE.

IOATIR FILED MYZ, 1912.

Patented Jan 13, 1914.

2 BHEETS-BHEET 2.

ma MW M JOHN A. CASHEL, OF WORTHINGTON, MINNESOTA.

INTEREST-COMPTING MACHINE.

Specicatlon of Letters Patent.

Patented J an. 13, 1914.

Application filed May 2, 1912. Serial No. 694,613.

To all 'whom it may concern.'

Be it vknown that I, JOHN A. CAsHEL, a citizen of the United States, residing at lVorthington, in the county of Nobles and State of hfli'nnesota, have invented certain new and useful Improvements in Interest- ComputingMachines, of which the following is a specification.

My invention relatesto computing machines, and particularly to those which are used in the calculation or computation of interest, annuities, etc.

The main object of my invention is to provide `a computing machine of simple construction, by which interest upon different amounts vat different rates may be quickly and accurately determined.

AI further object of the invention is to provide a machine of this character in which a plurality of sets of related calculating tables are so arranged 4as to permit of adjustment within a suitable casing or carrier to a position where they may be exposed to View, so that the operator may move to proper position the table which he desires to use, while the others remain concealed in order to prevent confusion.

The nature and scope of my invention will be more fully understood from the following description, taken in connection with the accompanyingr drawings, in whichl`igure 1 is a front elevation of a com puting machine embodying my invention; Fig. 2 'is an end elevation of the same; Fig. 3 `is a vertical section on the line 3 3 of Fig. l; Fig. 4 is a fragmentary sectional View of the right hand portion of the machine, showing the manner of mounting the interest rolls and the mechanism for rotating them; Fig. 5 is ,a detail sectional view of the time indicator shown at the lefthand side of Fig. l; Fig. 6 is an enlarged perspective view of one of the finders; and Fig. 7 is a side elevation of one of the interest-table rolls.

My interest-computing machine com prises a plurality of interest table prisms or cylinders 1, having pivot pins 2, upon either end journaled in disks 4, carried by a central shaft 5, which is journaled in the end walls of a casing 6. One end of the shaft is provided with a hand-wheel. 7, by which the disks may be rotated, and the pivot-pins 2' carry pinions 9, which intermesh, so that a gear-wheel l2, normally spring-pressed outwardly, may be pushed" into mesh with any adjacent `pinion when the entire series of prisms may be rotated axially by means of the thumb-piece 14. The prisms or cylinders 1, thus have a planetary movement,- that is to say, each is rotatable upon its own axis and bodily around the common central axis.

There are vpreferably .thirty-one prisms, one 'for each day of the month, and each prism is provided with a plurality of faces carrying respectivel series of gures indicating the interest or a certain number of days for varying amounts. In Fig. 7, I have shown three faces of a hexagonal prism showing the interestfor twenty-five days at 4, 5, and 6 per cent., respectively, upon amounts ranging from one hundred to nine hundred dollars. If desired, the rate per day for each amount may also be indicated in each space.

Above the skeleton day-cylinder above described, I may provide a corresponding skeleton cylinder having twelve interestbearing prisms for the different months.v

The manner of mounting and operating these prisms is exactly similar to that previously described in regard to the day cylinder, and I have indicated the corresponding parts by the same reference numerals primed. A third multiple-prism cylinder to indicate the interest for a series of years may be placed above the monthly cylinder if desired.

The method of operating the portion of my machine above described for the purpose of determining the interest for any amount will now be understood.

To find the amount for any number of days, the skeleton cylinder is first turned by means of the hand-wheel 7, until the proper day-prism is in alinement with the sightslot 15, extending across the front of the casing, which is indicated by the pointer 17, standing opposite the corresponding numeral on the face of the hand-Wheel 7. The cylinder is held in any set positionby the dog 37, which rides over the toothed locking wheel 36, The thumb-knob14 is then pushed inwardly until the spur-gear 12 is in mesh with the adjacent pinion 9, after which the series of prisms may be rotated in unison about their axes, until the face bearing the series of interest computations for the desired .rate per cent. is opposite the sight-slot.l Extendinv longitudinally of the slot is a series of numbers, from one hundred to nine hundred, which indicate the principal amounts corresponding with the adjacent interest computations. If desired, an indicator 20, having a magnifying lens 21, shown in detail in Fig. 6, may be mounted upon a guide-rod 23, and adapted to be slid over the res which are to be read. To further facllitate the rzpid calculation of interest between certain ates, I provide a coplerating set of disks bearin upon their peri eries numbers correspon ing respective y to the number of days lin a year and to the number of months, with subdivisions for the days of each month. These two disks 25, 26, are mounted upon the axle 28, the former loose thereon and the latter splined thereto. The loose disk 25 carries upon its peri hery the 365 subdivisions, and is normal y in zero position, being returned after each operation by -means of a torsional spring 29.

The complete operation of m machine will be clear from the foregoing escription.

Let it be desired to determine the interest upon five hundred dollars at five per cent., from March 14th until April 8th. The disk 26 is first rotated by means of the thumbknob 30, until the date March 14th appears in the sight-slot or window 32; then.- by pressing inwardly upon the knob, the notches or serratio 33, upon the adjacent edges of the diskslllsii and 26, are engaged. Now upon turning the\locked disks until the date April 8th, appears behind window 32,

the numeral 25, indicating the number of days between the two dates, will appear at the window upon the disk 25. As soon as pressure upon the knob 30 is released, the spring-operated disk 25 will be disengaged from the disk 26 and will return to zero position,l suitable stops 3 4 being provided to limit the movement. lslaving thus de-- termined the number of days between the required dates, the main skeleton cylinder is rotated by means of the wheel 7 until the 25th day prism is opposite the sight-slot 15. After rotating the prisms upon their axes by means of the gear 12, as previously described, until the 5 per'ce'nt. face is visible in the slot,l5, the indicator 2Q is; slid along the lr'odf23 until itis opposite'the sum `500 and the adjacent iiiterest'amofunt may then be read directly as $1.74. y These manipulations can be made very rapidl and the simplicity of the machine Will e appreciated by bankers and others who are required to determine uickly and in rapid succession the interest etween certain dates upon varying amounts. at different rates.

I have described in detail the specific consfruction illustrated in the accompanying drawings, for the purpose of disclosing an embodiment of my invention, but I am aware that various changes may be made therein without departingl from the scope of m claims or the spirit of my invention.

1. In an interest-computing machine, comprising a revoluble disk having upon its periphery a series of numerals arranged in arithmetical progression from unity upward, a spring normally causing said dlsk to assume a zero osition when unrestrained, a second revoluble disk coaxial with said first disk and having upon its eriphery successive series of numerals indicating the days of each month, means for rotatin said second disk independently ofthe rst-named disk, means for permittin one disk to be moved toward the other dis and means for causing a locking engagement therebetween, said spring operating to release said en agement when the parts are unrestrained, t ereby permitting the first-named disk to return to zero position.

2. An interest-computin machine comprising a casing having a sight-slot therein, a revoluble frame journaled in said casing, an annular series of revoluble cylinders journaled in said frame and rovided with intermeshing pinions, each o said c linders having inscribed thereon a plura ity of series of numerals indicating amounts of interest on sums varying progressively, each series being at a different rate, and the interest amounts upon adjacent cylinders differingby 4a unit period. of time, and a spurgear slidably mounted in thevcasing and normally out of engagement with said pinions, 'but adapted to be moved into mesh with any adjacent pinion of the series, whereby the desired series of numbers may he brought beneath said sight-slot.

Y. n .testimony whereof I ailix my signature inpresence of two wltnesses.

y JoHN A. CAsHEL. Witnesses:

HENRY NYs'rRoM,

ERNEST THOMPSON.

O opiel of thin patent may be obtained for ve cents each, 'by addressing the Commissioner of Patents, Washington, D. C.

Images