US1460469A - Computing machine - Google Patents

Description

. y 3, 1923. L Z-60,459

L L. ANSART COMPUTING MACHINE Filed Jan. 25 1921 Patented July 3, 1923.

UNITED STATES A were PATENT FFIc LOUIS L. ANSART, OF NEW YORK, N. Y., ASSlIGNOR TO UNDERWOOD COMPUTING MACHINE COMPANY, OF NEW YORK, 'N. Y., A CORPORATION OF NEW YORK.

oomru'rrne MACHINE.

Application filed. January 25, 1921. Serial No. 439,723.

To all whom it may concern:

Be itiknown that I, LoUIs L. ANsARr, a citizen of the United States, residin in borough of the Bronx, in the county oi the Bronx,city and State of New York, have invented certain newand useful Improvements in "Computing Machines, of which the following is a specification.

This invention relates to improvements in computing machines capable of efiecting algebraic computations, and of indicating the correct results whether positive or negative, and is in the nature of an improvement on the application of Louis E. Giles,'Serial :No. 392,96et, filed June 30, 1920 (now Patent No. 1,414,355, dated May 2, 1922).

In the machine disclosed in said application the opening in the casing must be wide enough to expose three rows of figures, and when the shutter .is in its normal position, there is exposed, in addition to the row of positive digits from which the correct reading of positive results may be obtained, a row of negative digits at one side thereof. Also, when the'shutter is positioned to give the correct reading of the negative result, such result must be read from two rows of negative digits on opposite sides on the row of positive digits and certain digits in the row of positivedigits will always beexposed. Obviously, the showing of unnecessary digits both when reading positive results .or negative results and the necessity for reading negative results from two rows, give rise to an undesirable condition, in that there is a tendency to confuse the operator in reading such results. It should be understood that such machines may be modified to enable reading of negative results from one row, and to necessitate the reading of positive results from two rows.

An object of the present invention is to provide means whereby upon changing from a positive to a negative result, or vice versa, the result may be read from a single row of digits without shifting 'theunits wheel to run in the fugitive unit.

Another object of the invention is to ob tain a totalizer or register in which both positive and negative'results may be read from the same row of digits.

Another object of the invention is to pro vide a totalizer and shutter such that the latter may be utilized to .point out in a row of positive and negative digits in the numeral wheels the positive digits from which the corresponding positive result is to be read or the negative digits from which a negative result is to be read.

A. further object-of the invention consists in so arranging the positive and negative digits on the numeral-wheels, and providing a shutter of such shape that, when'theshutter is positioned for reading a positive result, all of the negative digits will be obsoured, and that, when the shutteris properly positioned for reading a negative result, all of the digits except those from which the correct negative result is read will be obscured.

in. carrying out theinvention, the nu- Inerals from which positive results may be read, called. positive digits, and the digits from which negative results may be read, called negative digits, may be arranged in three different sets,'peripherally of each of the numeral-wheels, one of said sets being of one kind oi digits and the other two of the other kind of digits. These digits may also be arranged in rows of three across the periphery, the two digits of the same kind in each row being complements to the base nine and ten. respectively, of the digit of the other kind in said row. Provision may also be made of means for directing attention to row of digits extending across all of the numeral-wheels trorn'which both positive and negative results may be readwithout shifting the units wheel in order to run in the fugitive unit.

in case the single digit of one kind in each row of three extending across the periphery of a numeral or number-wheel is a positive digit, positive results or the complements of negative results may always be read from the positive digits in the row above referred to. and negative results may I be read from certain negative digits in said row. in order to facilitate the reading of such positive and negative results, provision may be made of a shutter, which, in its normal position, leaves exposed all of the positive digits and covers or obscures all of the negative digits in said row, from which readings are to be taken,.and which, in case of a negative result,- when properly positioned in accordance with the position of the last significant digit in the complement of said negative result, will expose only the negative digits, from which the correct nega wheel.

tive result may be read, and will cover or obscure all of the positive digits and all of the erroneous negative digits. Preferably,

the positive and negative digits are of characteristic appearance, so that they may be easily distinguished from each other, but

thisdifi'erence in appearance is not essential in view of the fact that the shutter will al ways conceal all of; the erroneous digits.

Preferably, for a reason to be brought out tive digit will appear in the middle, the negative digit, complementary thereof to the base 10- appearing to the left thereof, and the negative digit, complementary to the base 9, appearing to the right thereof. The arrangement of the negative dig1ts,'w1th reference to the positive digits, may be re versed, relative to the arrangement just described, and still other arrangements of the digits in each row-of three may be made.

Obviously, with a proper organization 01' the machine, oneset of negative digits and two "of positive digits may be used on each Positive and negative results may beread directly from the number-wheels without the use of a shutter, the correct positive result being always readable directly from the-positive digits in case of the preferred arrangedigits complementary to the base 10. of the remaining digits of said complement. In

order to facilitate the reading of such re g the computing wheels and the shutter."

sults, however, provision may be made of a shutteror reading gage having a set of digit-exposin openings, suitably spaced so that, when-t e shutterv is properly 1 positioned, only .the positive digits may-be exposed therethrough, and having a second set of digit exposi-ng openingsfsimilarly spaced, the openings of the two sets being so positioned, with reference to each other, that, when the openings of the first set are positionedto expose the complements t0 the base 9 of the positive digits in the. row from which readings are to be taken, the openings of the second set, which are to the right of those of the first set, will expose negative digits complementary to the base 10? ofthe corresponding positive digits in the reading row. It should be understood that, with the digits'arranged in the preferred form on the numeralswheels, the open-- i'ngs at the adjacent ends of thetwo sets in the shutter will come together, and the length of the shutter will be'l'ess than that I required in case the arrangement is the re verse of the preferred form. It should also computing wheel. *IIlBIli? of the digits on the numeral-wheels, and the correct negative result'may be read be understood that use may be made of a reading gage adapted merely to point out,

-when properly positioned, the digits to be l on. a large scale,showing a positive num-.

and the reading gage, or shutter. in its normal position to enable reading of the posi tive result. u

F igure-3 is a view similar to Figure 2, but showing a negative .number registered upon the computingwheels, the last significant figure of the complement of the negative number being on the units wheel and the shutter positioned accordingl Figuie 4 is a view similar. to Figure 3, showing a negative number registered upon the computing wheels, and the reading gage for the'shutter positioned properly, the position of the'shutter' being determined by the last significant figure of the complement of the negative result, which in this figure is on a computing" wheel other than the units her-registered upon the computing wheels,

Figure 5 is a fragmentary perspective view of the shutter, parts of which are broken away. v

Figure 6 is a 'd'ev'elop'ed'view of the periphery of one of the numeral-wheels used in connection with the present invention.

Figure 7 is a fragmentary sectional side view of that part of the d'evice shown in,

Figure 1 bringing out'the relationship of Figure 8 is a perspective 'view of one of the computing wheels, showinga notch extending across the periphery thereof.

.Figure9 is a developed view of the periphlery of a computing or numeral-wheel of a modified form, the digits on each side of a central digit being reversed with reference to the position of the same digits, as-shown in Figure 6. 3

The Underwood bookkeeping machine, to

which this invention is applied, includes a typewriter-frame 10, a computer casing 11, typewriter keys includin numeral-keys 12,

'and numeral-wheels 13, t e latter being revolubly mounted in the casing 11 and actuable for addition or subtraction by computing mechanism including pinions 14 having one-Way connections with said numeralwheels, one form of such mechanism being disclosed in the patent toIHans Hanson, No. 1,278,812, granted Septei'nber 10, 1918.

The positive and negative digits are pref erably shown on the number-wheels, as usual, in black and red, resnectivel'y, and are indicated on the drawings by means of solid and open figures, respectively. In the pre- .ferred arrangement, shown in Figure 6,

the positive digits are arranged in one direction around the periphery, and the nega- 'tive digits are arranged in the opposite didigits are on separate strips, it will be a comparatively simple matter to change from the arrangement shown in Figure 6 to that shown in Figure 9. I

Machines of this character are used only.

, for computations in which the results lie suiiiciently within the range of the register that no digit of the result will be registered on the wheelof highest denomination, this wheel serving only to indicate whether the result is positive or negative, being moved backward and forward only one step, to show a positive 0 through the sightopening 16, thereby indicating a positive result, or to'show a positive 9 through said sight-opening, thereby indicating a negative result. In case the positive O lies at the sight-opening, the' positive result may be read from the positive digits on the numeral-Wheels, and, in case a positive 9 lies at the sight-opening, the number read from the positive digits will be the complement of the correct negative result, which may be read by means of the negative digits complementary, to the base 9, to'the positive digits until thelast significant digit of the positive digits is reached, and then by reading the negative digits which are comple mentary, to the base 10, to the remaining positive digits. It will be evident that the left-hand negative digit on the numeralwheel of highest denomination and the right hand negative digit on the numeral-wheel of lowest denomination will never be used,

. vision is made of a shutter or reading-gage 17, by which attention may be called to the proper positive digits, giving a correct'positive result,or to the proper negative digits from which a correct negative result may be read. As herein disclosed, the shutter or gage is provided at its left with a series of openings 18, so spaced that, when the shutter is placed with one of the openings over a digit on one or" said numeral-wheels,-

the other openings will be positioned over corresponding digits on the other numeral-- wheels. For example, as shown in Figure 2, when the shutter is in its normal position, the positive digits on the various numeral wheels will be displayed through the sightopenings 18, and all of the negative: digits will be covered or obscured. The shiitter is also provided with a second series of openings 19, having the same spacing as those of the firstset, and so positioned relatively to the first series that the adjacent end openings of the two series will come together and form one opening 20 of double width,

In case the numeral-wheels are turned to show at the sight-opening, as in Figure 2, a positive 0 .on the numeral-wheel of highest denomination, it will be understood that theresult of the computation is positive and the result %7640 will be read from the notch 22, positive results may be readthrough the set of openings 19.

Vfhen the numeral-wheels are brought to the position shown 1n Figure 3. in any manner, as, for example, by subtracting 309614 I from the positive number 2476420, shown in Figure 2, the appearance of the positive 9 of the numeral-wheel of highest denomination will indicate that the resultis negative. In order to read such negative result, the shutter 17 is moved to the 1th to bring the solid portion at the right of the sight-opening 20 over the last significant digit, which, in this case. is the digit 67* on the numeral-wheel of lowest denomina tion.

may then be read through said shutter. in

connection with setting the shutter to read a negative result, the typist has onlv to bear in mind one commonly accepted definition of a significant digit. namely, that it is one of the numerals from 1 to 9, inclusive.

it the numeral-wheels are then brought to the position shown in Figure 4,.as, for example, by subtracting (336026 from the result shown in Figure 3, the shutter is moved farther to the left than for reading in Figure 3, the last significant positive digit in this case being on the fourth wheel from the right of the register. With the shutterso positioned, v the correct negative result The correct negative result 61974:

' sary to cover the positive 698000 may be read through the shutter. It should'be understood that after taking a reading, the shutter 17, if displaced from its normal position taking said reading,

should be restored thereto as soon as the act of reading is completed. be "slidably mounted, in grooves in guideblocks 23, fastened to the casing 11 by means of screws 24; and the restoration of theshutter to its normal position, after taking a negative reading, may be effected bymeans of a spring '25, attached at one end to a lug Qfifixed on the shutter, and at the other end to a fixed part of the machine. In

order that the shutter, inits movement to -the left from its normal position, may be stopped at the proper position-to give the v\r"" =urect negative reading, provision may be 'iiade of 'a' lug or projection 27, adapted toenter grooves 28 in the right-hand numeral-wheels when such wheels arepositioned to show a positive'0 at the'sightopening. As indicated in Figure 3, the lug -27 prevents the shutter from being moved farther to the left in Figure 3. than is neces- 6 appea ring on the numerahw-heel of lowest denomination; said lug serving to engage the fourth-numeral-wheel when the numeral-wheels are positioned, as shown'in Figure 4e. to-cause the. portion of the shutter immediately to theright of the double opening to cover the positive digit on said fourth wheel from the right. The ends of the grooves 28 in the various numeral-wheels may be beveled, .so as to facilitate the entrance of the lug 27- therein, when the numeral-wheels are slightly displaced from their proper positions.

It is evident that in case of a negative result, such result is read from thenegative digits complementary,.to the base nine, to

the-positive digits appearing at the sightopeiring, until the last. significant positive digit is reached, and then from the negative digits which are complementary, to the base ten, to the remaining positive digits. \Vhcn 'the arrangement of negative digits with reference to the positive digits isthat shown in Figure 6, it will beevident that the digits ;of the higherdenominations in the negative result will be read from the right-hand negative digits" on certain of the numeralwheels, and the remainder of the result will be read'from the left-hand negative digits, thus enabling the use of a shutter in which the adjacent openings :18 and.1 9 of the two sets come together and form an opening of .double' width. In case the arrangement of digits is that shown in Figure 9, it will be evident that'the digits of. higher denominations in a negative result will'be read from the left-hand digits on the numeral-wheels, and that another digit, or' digits, of lower denomination will be read from the right-' The shutter may.

ative digit on the numeral-wheel of lowest hand negative digits, which would necessitate the spacing apart of'the adjacent openings l8 and 19 in theshutter, so that the right-hand open ng 18 would be positioned oppositea negative digit at the leftof one numeral-wheel, and the left-handopening of the set of openings 19'wouldbe posltioned opposite theright-hand negative digit on the numeral-Wheel of next lower denomination. r

It willbe evident, therefore, that a shutter for use'with numeral-wheels having the arrangement shown in Figure 9 would be longer than one for use with numeral-wheels having the arrangement of digits as that shownin Figure 6; and,'furtherm0re, that the sight-opening would have to be of greater'length to expose the right-hand negdenomination.

It would be possible to use the right-hand set of openings 19 to point out the correct fig ures of the positive result and toread the negativeresult by moving the shutter to the right to proper-position for'such reading. It is found, however, that it is much easier to properly-locate the shutterby moving it to the left, as disclosed herein, to the posit'ion'in which the solid portion of the shutt er to the right of the double opening-covers the-last significant positive digit.

Another advantage of the present arrangement resides in the fact that'the proper' 1. In an algebraic computing machine,-in

combination, dials having figures torepresent positivevalues, and other figures to represent negative values, each dial having one set of one kind of figures and two sets of the other: kind, and means whereby attention may'be directed to a row of figures of the first set togive'a correct reading of a. result corresponding to the kind of figures in said set, and whereby attention :maybe directedto a row of figures of the other two sets from which results of the corresponding kind may be read.

" 2. In an algebraic computing machine, in combination, dials, including one for each of a plurality of denominations. as units,

-tens, etc., said dials having both positive and negative figures, each dial having one set of one kindof figures and two sets of the other kind, and means for directing attention to a row of figures. of the first .kind' all from which results of that kind may he read, and for directing attention to a row of figures of the other tWosets from which results of the corresponding kind may he read.

3. In a computing machine, the combination with a set of dials, each having a set or" positive digits arranged around its periphery, a negative digit at one side oi each positive digit and complementary thereto to the base nine', and a negative digit at the opposite side of the positive digit, complementary thereto to the base ten, of a cover for said dials having a sight-opening to enpose a single line of positive and negative digits, to enable-positive results to be read from the positive digits and negative results to be read on some of the dials from the negative digits complementary, to the base nine, to the positive digits at the sightopening, and on the remaining dials from the negative digits complementary, to the base ten, to the associated positive digits 4. In an algebraic computing machine, in combination, a series of dials, each having a-series of positive digits and tvvo series of negative digits, said digits arranged one under another upon said dials, so that, on one side of each positive digit, there is a negativedigit compiementaiy to the base nine, and on the other a negative digit com- I may be read, a positive result or the complement of a negativeresult being read from the positive digits, and, in case of the latter, the correct negative result being read from the negative digits complementary to the base nine until the last significant figure of the complement of the negative resultis reached, and then from the negative digits complementary to the base ten.

5. in an algebraic computing machine, in combination, a series of dials having positive and negative digits thereon, each of said dials having thereon a set of digits of one kind and two sets of digits of the other kind, all of the digits arranged one tollowing another on said dials, so that, on one side of each digit of the first set, there is a di it complementary to the base nine, and on the other a digit complementary to the base ten, and means to indicate a-rovv of digits from which the results of computations may be read, a result of the first kind or the compiement of a result of the second kind being read from'the digits of the first set, and, in the case of the latter, the correct result oi the second kind being read from the digits er the second kind complementary to the base nine until the last significant figure of the complement of the result of the second hind is reached, and then from the digits of the second kind complementary to the base 15631.,

6. In an al ebraic computing machine, the combination Wih dials, each' having thereon positive and negative digits, of a shift-able shutter, so shaped that, when roperly positioned, there Will be exposed t ere through only positive digits, giving a correct reading a positive result or the cornplement or a negative result, and, in the latter case, When moved to another position, While the dials remain in the same positions, there will be exposed therethrough only negative digits giving the proper negative result.

11in an algebraic computing machine, the combin qtion Wi' dials, each having thereonpositive ano negative digits, of a shittabie shutter, having in alignment, t sversely of the dials, digit-exposing o enings, so arranged when the shutter properly positioned, here will be exposed therethrough positive digits, givin a cor ct rea ng of a positive result or too com- 6 7 element or atter case,

result, and, in the i to another position, the erethrough only the nega n the proper negative resu t,

8 In an algebraic computing machine, the co inati n W dials, each having thereon positive and negative digits, of

manually-operable snuttenso shaped that, when properly positioned, attention wiil he directed to positive digits in a certain row, gl ing a correct reading of a positive result or toe complement of a negative result, and, in the latter case, when moved to another I position, attention will be directed to negative digits in said row, giving the propernegative result.

9. In an algebraic computing machine, the combination with dials, each ha thereon positive and negative digits, 0: means directing attention to-a single row of positive and negative digits on said dials, and a shutter shiftable transversely of the dials, and so shaped that, when properly positioned, attention will be directed to positive digits in said row, giving a correct reading of a positive result or the complement of a negative result, and, in the latter a case, when moved to another position, a tention will be directed to negative digits in said row, giving the proper negative result.

10. combination, a set of dials, each having set positive digits arranged one direction. and two sets of negative digits arranged in the opposite direction, so that the digits will lie in rows of three across the dial, the two negative digits in any row being on opposite sides of the positive digit and complementary thereto to the base nine to the base ten, respectively, a shiftable {shutter having two sets of openings in alignment, the openings of each set being spaced being on opposite sides of the positive digit so that correspondingly positioned digits on the difi'erent dials may be exposed there through simultaneously, said sets of openings being so positionedthat the. adjacent openingsof thetwo sets merge, forming a central opening of double width, and a handle for saidshutter attached thereto at a point opposite the middle-of the doublewidth opening 11. In com mation, a set of dials, each having a set of positive digits arranged in one direction, and two sets of negative di its;

arranged in the opposite direction so t at the digits will lie in rows of three across the dial, the two negative digits in any row and complementary thereto to the base nine and to the base ten, respectively,a shutter having two sets of openings in alignment,

the openings of each set bein spaced so that correspondingly positioned digits on the different dials may be exposed therethrough simultaneously, said sets of. openings being so positioned that the adjacentopenings of the two sets'merge, formin a central open-' ing of doublewidth, a ban le for said shut- 'ter attached thereto at a point opposite the middle of the double-width opening, and a casing for said dials having a sight-opening of sufiicient length to expose all digits in the reading row, except the left-hand negative digit on the extreme left-hand dial, and the ri ht-hand negative digit on the extreme rightand dial, said casing having a notch at each end of saidsight-opening to receive said handle. a

12. In combination, a set of dials, each having a set of positive digits arranged in one direction, and two sets of negative digits arran ed in the opposite direction so that the digits will lie in rows vof three across the dial, the two negative digits in any row being on opposite sides of the positivedigit and complementary thereto to the base nine' and to the base ten, respectively, ashiftable shutter having two sets of openings in alignment, the openings of each set being spaced so that correspondingly positioned digits on the different dials may be exposed therethrough simultaneously, .said

thereona set of positive digits and two sets of negative digits, of a shutter shiftable transversely of the dials along a certain row of digits thereon, and so shaped that, when properly positioned, the positive digits in said rowwill be exposed to give the correct reading of a positive result and all the negative digits in, said row, covered or obscured, and, in case of. a negative result,

when properly positioned, negative digits partly from one set thereof and partly from the other will be exposed to give the correct reading of the negative result, and concomitantly all of the positive digits in saidv row and all the erroneous negative digits in said rowwillbe covered or o'bscured.

14. A reading-gage for use in an adding and subtracting machine, having dials with positive and, negative digits thereon, each dial having a set of'digits'o'f one kind and two sets of digits of the other kind, said digits arranged one under another,-and, each digit of the first set having in line therewith, across'the dial, a'digit of one of the other sets which is a complement thereofto the base nine and a digit of the remain-' ing set which is a complement thereobto the base ten, said gage adapted to overlie one row of digits on said dials, and, when properly positioned, to obscure in' said rowall of the digits of the two sets of the same kind, so that the correct reading of a result' of the first kind may be read from,

digits of the first set, positioned in said row, and, in case of a result of the other kind, to obscure in said row all digitsof the first set and all erroneous digits of the other two sets.

15. A reading-gage for use in an addin and subtracting machine, having dials wit digits arranged one under another thereon, each dial bearing positive and negative digits thereon and having a series of one kind and also a series of the other kind on each side of the first series,'t he digit on one side of each digit of the middle series being a complement thereof to the base nine, and the digit on the other side beingv a'complement thereof to the base ten, said gage having a row of single-digit-exposing openings, spaced "so asto expose only digits of corresponding series on the different dials, and a second row of similar and similarlyspaced openings in alignment with the first,-

at one end thereof, the two series of openings being so positioned relatively to each other that, when both are partly in use,

ios

digits which are complementary to the base nine of the middle digits will be exposed on certain dials through the left-hand series of openings, and the digits which are complementary to the base ten relative to the middle digits may beseen through the open-' ings of the right-hand row, all the erroneous digits being obscured.

16. A denominational element for an arranged in transverse rows tive and negative digits thereon, a set of digits of one kind being arranged in order around the periphery thereof,-and two, sets of the other kind of digits arranged in the opposite direction, so that the digits will be f three, and the two digits of the same ind in each transverse row will be complementary, to the base nine and to the base ten, respectively, to the digit of the first set.

17. A numeral-wheel for use in an algebraic computing machine, having a set .of positive digitsarranged in order therearound-in one direction, and twosets of negative digits arranged in order thereon in theopposite direction, so that in line with each positive digit there will be two negative digits, one complementary thereto to the base nine and the other to the base ten.

18. In an algebraic computing machine,

the combination with dials, each having thereon positive and negative digits, of a shiftable shutter so shaped that when in its normal right-hand position attention will be called to positive digits in a certain row,

, giving a correct readin'gof a positive result or the complement of a negative result, and in the latter case, when moved to another position, attention willbe called to negative digits in said row, giving the proper negative result, and means to sto the leftward movement of the shutter W en it has reached the proper position for reading the negative result.

19. In an algebraic computing machine,"

the combination with numeral-wheels, each having thereon positive and negative digits, of a manually-operable shutter so' shaped that when in its normal right-hand'position attention, will be called to positive digits in a certain row,giving a correct reading of a positive result or the complement of a negative result, and in the latter case, when moved to another position, attention will be called to negative digits in said row, giving the proper'negative result, means to.

stop the eftward movement of the shutter when it has reached the proper position for reading the negative result, and means normally urging said shutter to its right-hand position.

20. In combination, a set of dials, each having a set of positive digits arranged in one directionand two sets of negative digits arranged inthe opposite direction, so that the digits will lie in rows of three across the dial, the two negative digits in any row being on opposite sides of the positive digit and complementary thereto to the base nine and to the base ten, respectively, and a shiftable shutter having two sets of openings in alignment,-the openings of each set being spaced so that correspondingly positioned digit-s on the different dials may be exposed therethrough simultaneously, said sets of openings being so positioned that the adjacent openings of'the two sets merge, forming a central opening of double width.

21. In combination, a set of dials, each having a set of positive digits arranged in one direction and two sets of negative digits arranged in the opposite direction so that the digits'will lie in rows of three across the dial, the two negative digits in any row being on opposite sides of the positive digit and complementary thereto to the base nine and to the base ten, respectively, a shutter having. two sets of openings in alignment, the openings of each set being spaced so that correspondingly positioned digits on the difierent dials may be exposed therethrough simultaneously, said sets of openings being so positioned that the adjacent openings of the two sets merge, forming a central opening of double width, and a casing for said dials having a sight-opening of sufficient length to expose all digits in the reading row, except the lefthand negative digit on the extreme left-hand dial, and the right-hand negative digit on the extreme right-hand dial, said casing having a notch at each end of said sight-opening and said shutter having locating means to engage said notches 22. In combination, a set of dials, each having a set of positive digits arranged in .one direction and two sets of negative digits able shutter having two sets of openings in alignment, the openings of each set bein spaced so that correspondingly positioned digits on the different dials may be exposed therethrough simultaneously, said sets of openings beingso positioned that the adjacent openings of the'two sets mer e, form ing a central opening of double width, and

a lug on said shutter adapted to enter grooves in said dials when the latter are positioned with the positive zeros thereon in the reading line.

LOUIS ANSART.

Witnesses:

CATHERINE A. NEWELL, JENNIE P. THoRNn,

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