US1203392A - Interest-computing and multiplying machine. - Google Patents

Description

H. H. OLSEN.

INTEREST COMPUTING AND MULTIPLYING MACHINE.

APPLICATION FILED DEC. 7, I9I4 NNW HERMAN H. OLSEN, OF WHITEHALL, MICHIGAN. l

INTEREST-COMPUTING AND MULTIPLYING MACHINE.

Specification of Letters Patent.

Patented oet. 31, 1916.

Application led December 7, 1914. Serial No. 875,872.

To all whom t may concern:

Be it known that I, HERMAN H. OLsEN, a citizen of the United States of America, residing at Whitehall, in the county of Muskegon and State of Michigan, have invented certain new and useful Improvements in Interest-Computing and Multiplyinfr Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled iI the art to `which it appertains to make and use the same.

This invention relates to an interest computing and multiplying device by means of which the interest on any desired sum may be computed at any given rate or per cent., for any particular' length of time, the device also being adapted to be used in finding products resulting from the multiplication of. any selected multiplicand by any multip 1er.

Itis the object and purpose of this invention-to construct a device of this character by meansA of which these several computations may be quickly and easily made and the'result accurately determined, said construction being of` very simple and economical design and very readily and easily operated. Y l

To these ends I have constructed the device shown in the accompanying drawing,

Figure 1 is a plan view of the device; Fig. 2 is a vertical section taken transversely of said device; and'Fig. 3 is a view of a portion of a computing sheet secured to one of the rolls used in the construction of the device.

Like reference characters refer to likel .transparent material, is slidably mounted,

bein retained by clips d against accidental `disp acement. On the underside of the plate a sheet of opaque material is fastened, said sheet having a plurality of rows of openings e which are separated from each other by cut-off partitions g as shown, these rows being located lengthwise ofthe plate and with openings in one row directly below those in the row next above.

'The rows `of openings are shown as vfour in number and immediately below said openings are mounted four rolls having journals extending into and rotatably mounted in the ends I) of the casing, there being provided turn buttons i by means of which the rolls may be manually operated. In the drawing said buttons are indicated at one end of the device but it is apparent they may be placed at either end or at both ends if desired. Each roll h has secured on the outer surface thereof a sheet c which has printed thereon a plurality of numbers at one end indicating a principal on which, an interest is to be computed and thence in horizontal lines indicating the computed interest at the rate of v6% per annum for a plurality of numbers of days. 'In the present construction said days are indicated in horizontal alinement in column Granging from ten days to five hundred and forty days, as will be apparent from reference to Fig. 1. The uppermost roll may be known as the thousands roll including all principals from one thousand to nine thousand, the second roll in similarV manner is the hundreds roll, the' third, the tens roll and the fourth, the units roll. It is of course apparent that additional rolls may be used, for instance, tens of thousands or hundreds of thousands ifneeded. The plate is slidably mounted in the casing and has secured thereto a tab lmiby means of which it may be drawn manually to different positions. Secured also to the underside of the plate c at the lower edge thereof, as shown in Fig. 1, is an opaque stripon which is printed a column of per cents. beginning at 1% and ending at 54%, this column being indicated at B. The principal on which the interest is to be computed will be read downward, that shown in Fig. 1 being 2854 and the principal column is denoted by reference character A. It will, be noted also that on the basis of a 6% computation the vertical column under each multiple of will be the same multiple of the principal indicated at the left hand side of the device as shown in Fig. 1 in the principal column A. For instance, in the vertical column under the number 180, disregarding the decimal point, will be found the figures, 6,000, 2400, 150 and 12, this being three times the numbers disclosed at the` left in Ycolumn A which are respeci tively 2,000, 800, 50 and 4. In the same cipal is 44 divided by 6.

manner under the number 540 the multiple is 9 and under the number 420 the multiple is 7; and if desired fractional multiples may be used as for instance, under the number 80 the multiple will be 14, and so on.

Let it be supposed that the interest on $2,854.00 at 6% per annum for 65 days is to be found. The operationl in such case is to turn the several rolls so that the principal reading downward from the upper roll will appear as 2,000, 800, .50 and 4 on the four rolls. Under the numeral of the days column C we find respectively 20.00, 8.00, .50 and .04, the sum of which is the required interest on the said sum at 6% for 60 days, or $28.54. or the additional 5 days attention should then be directed to the figures appearing under the number 50 in column C, the slide c being moved over to the left far enough that the cut-ofi' partition g will cut off Athe last figure appearing' on each of the rolls under the numeral 50. In this case such numbers are 1.67, .67, .04 and .00, the sum of which added to $28.54 is $30.92 or the required interest. It will be clear `that by operating the slide 'c the interest for any required number of days less than 10 may be obtained by merely cutting off' the last kfigure of the numbers appearing under a number in column C which is ten times the number of days desired.

The foregoing is the operation where the interest is at the rate of 6% per annum. Suppose however, it is desired to find the interest at a different rat-e forinstance, at 44% per annum. In this case it is necessary to interpolate a new principal which at 6% per annum will have the same interest computation as the given principal at 44%. This interpolation is made in the following manner: Let the principal be 62,854, the rate 44% and the time 100 days.

The first operation then is to pass to the per cent. column B to the position occupied by 44% and it will be noted that above such position, disregarding the decimal point,

reading downward, are the figures 1500, 600, 37 and 3, the sum of which is 2,140. These figures, it will be noted, bear the same ratio to those over the six per cent. character as does 44 to 6, and the interest on the sum thereof at six per cent. accordingly, is the same as the interest 0n 2,854 at four and onehalf per cent. for any given time. Or as will later appear, the multiplier byv which 2854 is multiplied to obtain the new prin- This is the new principal which should be used in place of $2,854,

l the rolls being operated so that 2,000 shall appear on the thousands roll, one hundred on the hundreds roll, 40 on the tens roll, with no figuresshowing on the units roll. Then by passing over to the figures appearf ing under 100 days will be found the interest on the sums2,000, 100 and 40 which added together will give the interest for 100 days at 44% on $2,854. The saine operation may lie-gone through with to determine the interest at any other desired rate for any other number of days. I have used a certain principal, namely $2,854, merely as a matter of examplebut any principal from $1.00 to $9,999.00 may be used.

It is of course apparent that the interpolated principal may at some times be more than 9,999. For example suppose that it should be 23,421. With four rolls only as in the device shown, it would be necessary to use the first four figures of this sum or 2,342 as the principal obtaining the interest on this sum at the desired rate for the required number of days and multiplying it by 10 and afterward adding the interest on the $1.00 additional at the given rate for the required number of days. Of course as heretofore noted the mechanism is not limited to the four rolls but may have additional rolls if desired, to take care of such contingencies.

Thefollowing illustration will show how the device may be used in the process of multiplying. The multiplicand is 2,854 which is to be multiplied by 623. For this multiplication the first operation is to pass to the numeral180 which is three times 60 in column C and add up the figures appearing underneath, disregarding the decimal point, the sum ,of which will be 8,562 which may be marked down in any convenient manner. This multiplies the selected multiplicand by the units digit 3. To multiply by 2 the tens digit the figures under the 120 numeral which is two times 60 are added together amounting to 5,708 to which an 0 is added making 57,080 by reason of the fact that the multiplicand is being multiplied by 20 instead of- 2l as in 623 the 2 occupies tens place; and finally to multiply by the 6 the figures under the 360 day numeral which isy six times 60 are added together amounting to 17,124 to which two 00s are added as the 6 is in. hundreds place making 1,712,400, then by adding together 8,562, 57,080 and 1,712,400 the vproduct will be obtained being 1,778,042. In the saine way multiplication by any of the fractional multipliers shown in the column indicated asr Multiplier column may be had to determine the product of any selected multiplicand by said fractional multiplier.

Various changes in minor detail of construction may be resorted to without departing from my invention which is adapted to be used in the manners indicated and in other ways not specifically described.` The claims define the invention and all modifications falling within their scope are to be considered as comprehended withinl the invention.

1. In a device of the character described, a casing, a closure mounted at the upper side thereof and having a plurality of rows of transparent sections therein, a roll rota-` tably mounted below each row of transparent sections, each roll having thereon a plurality of rows of computations of interest on a pluraiityof principals for different times at a given rate, saldv computations being adapted to show through the transparent sections of the closure, a column having represented therein the numbers of days for the said computations located at one side of the casing and with said numbers in operative alinement with the computations corresponding thereto and a .column at the opposite side of the casing secured to the slide containing a plurality of per cents.,

each being one tenth of the respective number of days in the days column directly opposite at the opposite side of the casing.

In a device of the character described, a casing, a closure mounted at the upper side thereof and having a plurality of rows of transparent sections therein, a roll rotatably mounted below each roW of transparent sections, each roll having thereon a plurality of rows of computations of interest on a vplurality of principals for different times at a given rate, said computations being adapted to show through the transparent sections of the closure, and a column having represented therein the numbers of days for the said computations located at one side of the casing and with, said numbers in operative alinement with the computations corresponding thereto, and a second column similai-1y located at; the vopposite side of the casing denoting a plurality of per cents., each per cent. being one tenth of the corresponding numbers of, days in the first column. Y

In testlmony whereof I affix my signature 1n presence of two Witnesses. y

HERMAN H. oLs'EN.

Witnesses c ALBERT MICKELSON, J oHN HAVERKATE.

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