US1288448A - Mechanical calculator. - Google Patents

Description

J. B. SKEEN.

MECHANICAL CALCULATOR.

APPLICATION FILED 0CT.25.1915.

Patented Dec 17,1918.

2 SHEETS-SHEET I.

JESSE 13. SKEEN, OF LOS ANGELES, CALIFORNIA.

MECHANICAL CALCULATOR.

Specification of Letters Patent.

Patented Dec. 17, 1918.

Application filed October 25, 1915. Serial N 0. 57,703.

To all whom it may concern Be it known that I, Jnssn B. SHEEN, a citizen of the United States, residing at the city of Los Angeles, in the county of Los Angelcs and State of California, have invented new and useful Improvements in Mechanical Calculators of which the follow ing is a specification.

My invention relates to the mechanical manipulation of tables for facilitating and expediting arithmetical calculations such as computing contents of triangular solids,

computing wages, interest, trigonometrical problems and other like calculations.

I have illustrated my device in the accompanying drawings as applied to computing the contents of triangular solids and WM describe it as so applied.

In the drawings:

Figure 1 is an end elevation, partly broken away, of my calculator.

Fig. 2 is a top plan of Fig. 1 with parts in section.

Fig. 3 is an enlarged sectional detail on the line 3-3 of Fig. 1.

Fig. 4: is a bottom plan of a portion of Fig.

Fig. 5 is a top plan of Fig. 3, with a part broken away.

Fig. 6 is a-fragment of the table used in computing the contents of triangular solids.

While different tables may be mounted on the cylinder of this device, this description will be confined to the use of an earth work table, a fragment of which is shown in Fig. 6, consisting of calculated volumes of triangular sections fifty feet long, having bases varying from one-tenth of a foot to onehundred feet and any given altitude, it being understood however, that the principle underlying the use of the earth work table applies to the manipulation of other tables. The different tables would be arranged on the cylinder in the form best suited to perform their functions, with a possible variation in the number of keys on the index dial.

In the drawings 10 is a base plate on which are mounted standard 11 and end plate 12. A shaft 13 is revolubly mounted in said standard and plate. A table cylin der 14, preferably hollow, is secured upon and carried by said shaft. On the periphery of the cylinder is mounted table 15 which is used in calculating the contents of triangu lar solids as in earth work calculations in railroad work. Ciroumferentially the table is arranged for calculations up to twenty feet, which may be used as either base or altitude. In the illustration it is the base, and each foot is subdivided into tenths. Each tenth of foot has a line of longitudi nal computations correctly worked out representing either base or altitude. In this illustration it represents altitude. Each longitudinal line of computations is divided into groups of nine members so that in the present illustration we have a table composed of five groups and in each group there are nine circumferential columns of two hundred numbers.

The first group runs from 0.1 to 20 feet. The second group runs from 20.1 feet to 4-0 feet. The third group runs from 40.1 feet to feet. The fourth group runs from 60.1

to 80 feet. The fifth group runs from 80.1

to 100 feet. Additional groups can be added by lengthening the cylinder.

The first circumferential column is an indeX column. The circumferential column numbers of the second and subsequent columns are found by multiplying the several numbers of the first or index column by the quotient of twenty-five divided by twentyseven, but as this quotient is an interminable decimal I only use the first two figures there of and when the decimals to the right of the hundredths place exceed five I drop the decimals to the right of the hundredth place and add one to the hundredths figure.

On shaft 13 is secured a bevel gear 16 which meshes with a bevel gear 17 on shaft 18. On the other end of shaft 18 is a bevel gear 19 which meshes with bevel gear 20 on shaft 21. Shaft 18 is mounted in bearings 22 and 23 secured to end plate 12. Shaft 21 is mounted in bearings 24: also secured to end plate 12. A portion of end plate 12 is bent over as best shown in Figs. 1 and 3 and shaft 21 also passes through this part. A detent plate 25 best shown in Figs. 3 and 4 is secured to the bent over portion of plate 12 by rivet 26.

Shaft 21 has a head 21- which passes through the detent plate thereby keeping the plate from rotating on rivet 26. In the outer end of the detent plate are ten notches numbered from 0 to 9 and indicated by the numeral 27. These notches are engaged as desired by a detent 28 which is held by spring 29 in engagement with the detent plate at any desired notch. Detent 28 is carried by the handle 30 of what may be ranged 011 a circle and are held out of engagement with the tenth plate by springs, one of which 35, is shown in Fig. 3. Marked on the face of the index dial are the respective numbers of these pins which numbering runs from one to twenty as best shown in Fig. 2. The numbers could be placed on the heads of the pins. The index dial is rigidly attached to the head of shaft- 21 by rivets 36 so that said shaft will rotate when said dial is rotated. Cylinder 14 and gears 16 and 17 are inclosed in a casing 37 which is fastened to the base plate. This casing has a longitudinal sight aperture 38 which is covered by a transparent sight strip 39, preferably of glass, which has a sight line 40 running longitudinally thereof and group lines running transversely thereof. Indexes for the different groups are placed on the glass just above the sight line.

In the use of my device suppose I wish to know the cubic contents of earth work in a triangular section with a base of nineteen and nine-tenths feet and one foot altitude. I first turn the tenth plate to the position that the detent engages the notch marked 9. I then turn the index dial by means of the stop pin marked 19 and when said stop pin comes over the detent plate I apply a pressure on the top of the pin so that when the pin registers with the stop hole 33 the pin will enter it and stop the further movement of the index dial.

The movement of the index dial has caused through the connected shafts and gears the revolution of cylinder 14: to bring the longitudinal line of figures which give the desired answer at rest below the sight line on the sight glass. I then look at the first number of the group index marked 0.1 to 20 and read opposite 19.9 of the index column 18.3t3 cubic yards as my answer. If the base had been 99.9 feet instead of 19.9 feet and the altitude 9 feet instead of one foot'I would have looked in the last column of the group 80.1 to 100 opposite 19.9 of the index column and would have read 832.50 cubic yards as my answer.

By using other tables with suitable indexes on cylinder 14 and suitably spaced stop pins on the index dial my mechanism can be used for a large number of arithmetical calculations, the principle of operation being a revolving cylinder carrying the table; an index dial workably connected to the cylinder so that each revolution of the index dial will cause one revolution of the table cylinder; and suitable stop mechanism by which the index dial may be stopped at any point of its revolution at a given point and when so stopped a specific portion of the table cylinder will appear at a given point. The point at which the index dial stops will cause the stoppage of the table cylinder at the desired point to furnish the information wanted.

Having described my invention what I claim is:

A mechanical calculator comprising a base plate; a movable chart, bearing tables revolubly mounted on said base plate; a tenth plate having a stop hole therein adjustably mounted on said base plate; an index dial revolubly mounted on said base plate; an

operative connection between said cylinder and dial; and stop pins mounted on said dial,

7 said pins being adapted when pressure is applied thereto to enter the stop hole and prevent further rotation of said dial whereby the table cylinder is stopped in a predetermined position.

In-witness that I claim the foregoing I have hereunto subscribed my name.

JEssE B. SKEEN.

Copies 01' this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, no."

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