Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS1422944 A
Publication typeGrant
Publication dateJul 18, 1922
Filing dateJan 3, 1920
Publication numberUS 1422944 A, US 1422944A, US-A-1422944, US1422944 A, US1422944A
InventorsS. Edmondson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Calcttlatob
US 1422944 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

H. S. EDMONDSON.

CALCULATOR.

APPL|CATl0N.FlLED JAN.3, 1920'.

1,422,944, Patented July 18, 1922.

3 SHEETSSHEET I.

[72116 mtor H. S. EDMONDSON.

CALCULATOR. APPLlCATlON FILED JAN.3,1920.

1 ,422,94&. ate ted 111y 18, 1922.

3 SHEETSSHEET 2.

[Z Sffdmazads 07a H. S. EDMONDSON.

CALCULATOR.

APPLlCATlON FILED JAN-3,1920.

UNITED STATES PATENT OFFICE.

CALCULATOR.

Specification of Letters Patent.

Patented July 18, 1922.

Application filed January 3, 1920. Serial No. 349,242.

This invention relates to calculating devices and more particularly to devices for adding and subtracting quantities and generally the invention has as its object to provide a simple and inexpensive device for this purpose which will be of a compact nature and therefore adapted for ordinary desk use or even capable of being carried about in ones pocket, and which device may be readily manipulated to obtain the results required, in an expeditious manner. Another object of the invention is to provide a device of the class described devoid of complicated parts which would be liable to become disa-rranged or broken and which device may be instantly adapted for addition or for subtraction without any complicated adjustment of parts.

In the accompanying drawings Figure 1 is a perspective view of one form of the invention;

Fig. 2 is a bottom end view thereof;

Fig. 3 is a vertical sectional view on the line 3-3 of Fig. 1;

Fig. 4 is a perspective view of one of the number strips of this form of the invention;

Fig. 5 is a perspective view illustrating a modification of the form shown in Fig. 1;

Fig. 6 is a transverse sectional view on the line 6 6 of Fig. 5;

Fig. 7 is a plan view of one of the number strips in its incomplete form;

Fig. 8 is a' perspective view of the completed number strip, another portion of the structure being illustrated in perspective and in section;

Fig. 9 is a front elevation illustrating another modification of the invention; v

Fig. 10 is a vertical longitudinal sectional view therethrough;

Fig. 11 is a front elevation of a portion of the compensating means employed in connection with this form of the invention;

Fig. 12 is a perspective view of a portion of one of the number bars;

Fig. 13 is a fragmentary perspective view illustrating a portion of the compensating means shown in Fig. 11;

Fig. 14 is a view similar to Fig. 10 illustrating another modified form of the invention;

Fig. 15 is a detail vertical longitudinal sectional view illustrating a modified form of the structure shown in Fig. 5 of the drawings.

Figs. 1 to 4 inclusive illustrate the invention in its simplest form and this form will first be described and I will then describe the various modifications of which the invention is susceptible. In these figures the numeral 1 indicates in general the base of the device, which may be of any suitable material and one face of which is formed with ,a longitudinally extending series of relatively shallow 'grooves indicated by the. numeral 2 and clearly shown in Fig. 2 of the drawings. To this face of the base there is applied a cover sheet or plate indicated by the numeral 3 which may be of any material suitable for the purpose. When this sheet isapplied to the face of the base 1,

the grooves 2 will be closed at their front sides so as to form closed channels in which the number strips are to be slidably housed as will be presently explained. The sheet or face plate 3 is formed about midway with transverse series of openings two of which are indicated by the numeral 4 and the remaining ones by the numeral 5." The open-- ings 4 are intended to display numbers borne by the number strips and representing the oddcents in the result or total, and the openings 5 are designed to expose to View the numbers upon the respective number strips which indicate the total number of dollars. The face plate 3 is further formed in its portion between the series of openings 4 and 5 and the lower end of the device, with a transverse series of longitudinally extending slots severally indicated by the numerals 6, 7, 8, 9, 10 and 11. With the exception of the slot 11, the said slots are each widened at the upper "and lower-ends as indicated respectively by the numerals 12 and 13, this increase in width of the slots being in the direction of the left 'hand side of the device and resulting in the formation of shoulders 14. and 15 located respectively near the upper and lower ends of the respective slots. As a matter of convenience in describing the devlce and the manner in which the same 1s manlpulated in making calculations, the upper end wall of each slot' the numeral 18 and the same may be ofcar board, metal,-or any other material suitablefor the purpose, and is formed in its opposite longitudinal edges with series of notches 1-9. The strip is of dimensions to fit slidably in the respective groove 2 provided for its reception, and the said strips are so fitted as clearly shown in Figs. 2 and 3. The face of the strip has one-half of its length of one color and the other half preferably of a contrasting or distinguishing color and the purpose of this arrangement will presently be pointed out. Upon the said face of the strip there is printed a series 20 of numbers ranging from one to nine with a zero at each end of the series. These numbers are arranged consecutively in ascending order in the direction of the upper extremity of the stripand are all located .upon that portion of the face of the strip which is printed in a contrasting color and which portion of the 'face is indicated by the numeral 21. The strips 18 are of such length that when slid into their respective channels, their upper ends will abut against the closed upper ends of the channels and their lower ends will terminate substantially flush with the open lower end of the channels. Thus when the device is not in use the strips will all be completely housed and there will be no likelihood of the breaking off of any of the strips. Also the engagement of the upper ends of the strips against the upper end walls of the channels serves to limit the upper sliding movement of the strips in the channels, and their downward sliding movement is limited by striking up from each strip at or adjacent its upper end, for example that portion of the strip which bears the zero at the upper end of the series of numbers 20, a tongue which is indicated by the numeral 22 and which has its free end projecting in the direction of the lower end of the strip. Due to the provision of this tongue, when the strip is slid downwardly until the said zero upon the tongue is exposed in the respective one of the openings 4: or 5, as the case may be, the ton e wlll s rin into engagement in the opening and t e ree end of the tongue, will engage against the lower wall of the said opening for the urpose stated. Of course, should it be desired to for any purpose remove any ofthe strips, it would only be necessary to.

gue 22 so asto' press inwardly upon the ton cause the same to occupy the same plane as the remainder of the strip whereupon the stri could be slid downwardly without inter erence.

It willbe observed b reference to Fig. 1 of the drawings that w en the strips are in place the notches '19 will'be exposed to view in the respective slots 6, 7, 8, 9, 10 or 11 as the case may be, certain of the notches appearing also in the widened portions 12 and 13 of the slots. More specifically the notches at the left hand side of each strip will be exposed to view in a respective one of the slots for the entire length of the slot and certain of the notches at the right hand side of the stri will be exposed to view through the wi ened portions 12 and 13 of the next slot to the right. The numbers upon the number strips will, of course, be successively exposed through the openings 4 or 5 as the case may be as the respective strips are slid within their channels. The columns of numerals 23 and 24 are printed upon the plate or .sheet 3 at the right hand side of the several slots 6, 7, 8, 9, 10 and 11 the numerals 23 ranging in numerical order from l'to 9 inelusive from the lower end of each column to the upper end thereof and being printed in relatlvely large type, and the numerals 24 being arranged in numerical order ranging from 1 to 9 inclusive and from the upper end of each column to the lower end thereof. The numerals of the column are so spaced that they will be located opposite the notches in the respective number strip 18 when any one notch of the strip is opposite an one numeral of the respective column. Ihe numerals 23 are to be employed in adding, and the numerals 2a in subtract- 111 Tn the use of this form of the invention, a pencil point or any suitable pointed implement isemployed for shifting the slide. It is thought that the operation will best be understood by a specific example: As a matter of convenience in describing the use of the device, the number strips which are related to the slots 6, 7, 8, 9, 10 and 11, are indicated respectively by the numerals 6 7, 8*, 9"-, 10, and 11 Let it be assumec for example that it is desired to find the sum of the quantities $1.86, $7.34 and $2.15. The pencil point or the point of any other implement employed is first placed within that one of the notches in the strip 8 which is opposite the'numeral 1 in the corresponding column 23, and the strip is slid downwardly until the pencil oint strikes the lower end wall 17 of. the slbt 8. The pencil point is next placed in the notch in the strip 7 -which' is opposite the number 8 in thecorresponding column 23, and this strip is likewise slid downwardly until the pencil point contacts the end wall 17 of the slot 7. Next the pencil point is placed in the strip 6 opposite the number 6 in the corresponding column 23 and this strip is moved downwardly until the point of the pencil is stopped by the end wall of the slot 6. At this point it will be understood that the number 1 will be visible through the right hand opening 5 and the numbers Sand 6 through the openings 4. The pencil point is next placed in the notch in the strip 8 opposite the numeral 7 of the column 23 and is moved downwardly until stopped by the end of the slot 8. Then the point is placed in the notch in the strip 7 opposite the number 3 in the corresponding column 23 but as this notch is located within the bounds of the portion 21 of the strip, the strip is moved upwardly instead of downwardly until the pencil point strikes the upper end wall 16 of the slot 7 whereupon the oint is shifted along said wall to the le t, being thus brought into en agement in that one of the notches 19 in t e right hand end of the strip 8 which is substantially in registration with the said end wall of the slot, after which the pencil point is moved downwardly until it strikes the shoulder 14 within the said slot 7. Next the pencil point is engaged in the notch in the strip 6"* opposite the number 4 in the corresponding column 23 and it is moved downwardly until arrested by the lower endwall of the slot 6. The pencil point is now returned to the slot 8 and is engaged in the notch in the strip 8 opposite the number 2 in the corresponding column 23 but as this notch is located within the bounds of the portion 21 of the strip, the pencil point must be moved upwardly to correspondingly move the strip and until it strikes the end wall 16 of the said slot 8 whereupon it is moved to the left as previously described, and after entering the notch in the strip 9*, is moved downwardly until it strikes the shoulder 14 within the slot 8. The pencil point is next engaged in the notch in the strip 7 opposite the number 1 in the column 23 and is moved downwardly to the bottom end wall 17 of said slot. Finally the pencil point is en aged in the notch in the strip 6 opposite t e numher 5 in the corresponding column 23 and the pencil point is moved upwardly in the manner previously explained until it reaches the upper end of the slot 6 whereupon the pencil point is shifted to the left along said upper end until engaging with a notch 19 in strip 7 and finally drawn downwardly until striking shoulder 14. The total $11.35 will now appear in the openings 5 and 4.

As a simple example of the use of the device in subtracting. quantities, let it be assumed that it is desired to subtract $2.57 from $7 .64. The number slides 8 7 and 6* are first so manipulated that they will respectively display the numbers 7, 6 and 4 through the openings 5 and4. The pencil point is then placed in the notch in the strip 7 8 opposite the number 2 in the column 24 as distinguished from the column 23 in the process of addition, and as this notch is within the bounds of the portion 21 of the strip, the pencil point and strip are to be moved upwardly until the point is arrested by the upper end of the slot. The pencil point is next placed in the notch in the strip 7 opposite the number 5 1n the corresponding column 24 and is moved upwardly until arrested by the upper end wall 16 of the slot 7. The pencil point is finally placed in the notch in the strip 6 opposite the number 7 in the corresponding column 24 and as this notch is within the bounds of that portion of the strip below the portion 21, the pencil point and strip are to be moved downwardly until the point is arrested by the lower end of the slot whereupon the point is shifted toward the left along the wall 17 of the slot and in the groove 17 and thence in an upward direction until it strikes the shoulder 15. In this last movementof the pencil point the strip 7 will be moved upwardly one notch. The result, $5.07 will now be displayed through the openings 4 and 5.

In processes of addition, the strips are moved downwardly except when the notches in which the pencil point are to be engaged are located within the bounds of the portions 21 of the strip, but in the process of subtraction, the pencil point is moved up wardly except when engaged in a notch which is located within the bounds of the portion of any strip below the portion 21 whereupon it is moved in a downward direc tion. In other words, the manipulation of the device in adding is the reverse of that in subtracting. In order to guide the pencil point when it is moved laterally along the walls 16 and 17 of the slots 6, 7, 8, 9, 10'

and 11, it is preferable thatthe face of the body 1 be formed with transversely extending grooves 16 and 17 located respectively at the said walls 16 and 17. The foregoing is the general principle of operation followed in all forms of the invention and I will now proceed to a description of that form shown in Figs. 5 to 8 inclusive.

That form of the invention shown in Figs. 5. to 8 inclusive is very similar in its general construction and operation to the form previously described. In the first described form of the invention, the number strips are slidable and, of course, as any one of the strips is slid downwardly or upwardly, it must project beyond the corresponding end of the base of the device. Furthermore, the base of the device, in that form, must be of a length at least equal to the length of any one of the strips sothat the strips may be housed when the device is not in use. The purpose of the modification shown in Figs. 5 to 8 inclusive is to enable the device to be rendered much more compact without any way limiting its range of usefulness and with this object in view, the base or body of the device, indicated in general by the numeral 25, is formed approximately of half the length of the base in the previously described form of the invention and comprises a block of wood or other suitable material the opposite faces of which are grooved or channeled, as indicated by the numeral 26 providing intervening ribs or guides 27 and the end edges of the block are rounded substantially on the arc of a circle as indicated at 28, these rounded portions constituting continuations of the bottom walls of the grooves 26. Thus the body 25 is formed with a transverse series of channels which longitudinally circumscribe the said body. In this form of the invention the number strips, which are indicated by the numeral 29, are in the nature of continuous bands disposed to ride freely in the respective grooves or channels 26, the bands, of course, extending longitudinally about the said body 25. Thus instead of the substantially rigid sliding number strips of the previously described form, I provide in this modified form number strips in the nature of endless bands, and by this means am enabled to shorten the device substantially by half. Disposed against each end edge of the body 25 is a strip 30, these strips being secured in place in any suitable manner and having their ends flush with the lateral edges of the said body25. A backing sheet 31 is secured to the rear or under face of the assemblage of the body 25 and strips 30, and a face plate or sheet 32 is secured to the front side thereof, this face plate is provided with slots 33 arranged in a transverse series as in the previously described form of the invention and corre-- sponding to the slots 6 to 11 inclusive in the figures illustrating said form. Likewise the face plate 32 is formed with openin s 34 and 35 corresponding respectively to t e openings 4 and 5 in Fig. 1 and through which the totals may be read. I

I In the previously described forms of the invention, where a pencil or similar pointed implement is employed for shifting the number slides, it has been necessary to shift the pencil or other implement to the left and then manipulate the same to actuate that one of the strips immediately to the left of the one previously actuated. However, by the arrangement shown in Figs. 9 to 13 inelusive, this may be automatically accomplished. In these figures the numeral 36 indicates the base of the device which base is provided with grooves in its upper side to receive the number slides or bars indicated in general by the numeral 37. Each of these bars is provided at its forward side 5 i and its lefthand margin with an upstanding flange 38 which is'formed with series of notches 39 and 40. These notches are designed to be engaged by the fingers of the hand in sliding the bars up and down in manipulating the device and the notches of the two series are of different contours so that by the sense of touch one will be apprised of the shape of the notch engaged by the finger. Thus the notches 39 may be approximately semi-circular and the notches 40 may have fiat bottom walls. The notches 39 are defined by and located between rounded upward projections 41, and the notches 40 are defined by and located between sharply ridged projections 42. The groove in which the number slides 37 are slidably fitted are indicated by the numeral 43 and as stated are formed in the upper side of the base 36. In order to retain the bars withinthese grooves, retaining strips 44 are preferably set into the side walls of the grooves as'indicatedby the numeral 45 and project over and in contact or substantially in contact with the upper surface of the body of the respective strip, as clearlyshown in Fig. 12 of the drawings. A cover plate or sheet 46 is applied to the front face of the body 36 at the lower end thereof, and covers the corresponding ends of the grooves, the grooves being partly closed throughout the remainder of their lengths by the strips 44 as shown in the said Fig. 2 and also in Fig. 9. The front faces of the strips 44 bear series of numbers 47 and series of numbers 48 corresponding in all respects to the two series 23 and 24 previously referred to. Each strip 44 at a predetermined point is cut-away to provide a sight opening 49, the totals being visible through these openings and constituting the numbers appearing upon the front face of the number bars 37 and which numbers are indicated by the numeral 50.

.As' previously stated the number bars are to be shifted "by the fingers, and assuming that the notches 39 and 40 are of the contours illustrated in Fig. 12 the user of the sense of touch the direction in which any number bar engaged by the finger is to be shifted and, these bars are shifted in substantially the same manner as described with reference to the form of the invention shown in Fig. 1.

The spring operated compensating means heretofore referred to comprises a frame .51 which is rectangular and'to the opposite ends of which are pivotally connected bars 52, these bars being pivotally connected at thelr opposite ends as at 73 to the opposite lateral edges of the base 36 at predetermined points. By reason of this construction, the frame 51 may be swung to lie either at the upper or at the lower ends of the grooves 130 in which the number bars are slidably mounted. Within the frame there are slidably mounted a number of plungers 53, one

for each of the number bars, and springs 54 are disposed upon "the plungers and bear against a member of the frame and against any suitable stop or shoulder upon the respective plungers.

The plungers are preferably rectangular in cross-section as clearly shown in Fig. 13 and the openings through which they are fitted are of similar form so that the plungers will be held from rotation. Projecting laterally toward the left from each plunger is a' resilient arm provided at its extremity at its front and rear sides with fingers 56 which converge toward each other in the direction in which the respective plunger is to be moved against the influence of the spring 54, these fingers at their converging ends being integrally or otherwise connected with the edge of the arm 55 and at their juncture being rounded to form a nose 57 adapting the fingers to readily ride over the projections 41 or 42 as the case may be when the plungers 53 are moved against the tension of the respective'springs 54. One end of each plunger is provided with a finger piece or knob 58 to be enga ed by the end ofthe finger manipulating t e corresponding number bar, the said finger knobs 58 being located in the path of movement of the finger when manipulating the respective bars. It will be observed by reference to Fig. 10 of the drawings that when the frame 51 is in the posi tion shown in full lines in the said figure the ends of the plungers which carry the finger knobs 58 will be presented in the direction of the upward end of the device, the compensating device when in this position being adapted for the process of subtraction. On the other hand when the device is swung over the dotted line position shown in the said Fig. '10 it will be in position for use in the process of addition. ,In the first instance one of the fingers 56 of each of the plungers will rest in engagement in one or another of the notches '39 or'40 as the case may be in the respective number bar,

and in the second instance the other. finger 56 of each plunger will rest in one or an other of the said notches of the respective bar. In any event the fingers are so proportioned that when resting in such engagement with the respective bars, the arms 55 will be sprung slightly upwardly and supported in this position. Of course, the direction in which the arm is sprung will depend upon the position assumed by the compensating device as a whole. The numeral 59 indicates a double faced cam, and one of these cams is provided for each of the plungers and is f rmed or secured upon that wall of the frame 51 next adjacent which the arms 55 of the plungers are located when the plungers are normally retracted bytheir springs 54. As stated, the fingers 56 so engage the bottom walls of the notches 39 and 40 as the case may be as to slightly elevate the respective arms 55. Also as stated the cam 59 is provided with a double face. Therefore whether the compensating device is in the full or the dotted line position in Fig. 10,the movement of the plungers .under the influence of their springs 54 wilLcause the arms 55 to ride up upon the upper faces of their respective cams 59 and as a consequence the finger 56 which is then rearmost, will be so elevated as to clear the projections 41 and 42 and thus the sliding movement of the number bars will not be in any way interfered with. It will now be understood, particularly by reference to Fig. 10 of the drawings, that the frame 51 will limit the movement of thefinger manipulating any one of the bars when the finger is moved in the direction of the said frame. Therefore the plungers are so roportioned that their finger knobs 58 wil be located above the second projection from the one which is at any time in registration with the side of the frame which carries the cams 59. Consequently in shifting any of the bars, should it be required to shift the bar in an upward direction while the compensating device is in the dotted line position shown in Fig. 10, the finger will engage the respective plunger and this plunger will be moved upwardly with the number bar a ainst the tension of the spring 54. As the p unger moves in this manner, the rear finger 56 upon its arm 55 will ride over the projection 41 or 42 which is in its path and which is upon the next adjacent number bar to the left and which will engage behind said projection and thus when the finger is lifted, from the device and from engagement with the plunger and the first mentioned number bar, the said finger 56 will act upon the second mentioned bar to slide the same in a direction opposite that in which the first mentioned bar was moved.

In the first described form of the invention the downward or compensating movement of any number bar was limited by the engagement of the pencil or other point against the corresponding one of the shoulders 14 or 15 as the case might be but Fig. 14 of the drawings illustrates a modification of this arrangement and a structure .in which the fingers alone may be directly employed in manipulating the bar without the resort to the use of a pencil or similar employment. In this figure the movement of the fingers in either direction is limited-by a shoulder 60 and as the finger moves in either direction in manipulating the corresponding bar, and approaches the shoulder 60, it will ride over and depress a relatively weak leaf spring 61 arranged beside each of the number bars, depressing this spring to the dotted line position shown in Fig. 14. After the finger has'passed over this spring and has reached the shoulder 60, it may be shifted to the left and into engagement in a notch in the next adjacent number bar to the left of the one first mentioned, and then moved upwardly or down wardly as the case may be until such movement is arrested by its engagement against the end of the said leaf spring 61 which end of the spring is preferably turned inwardly as at 62 to provide a well defined shoulder or sto element.

'1 hat form of the invention shown in Fig. 15 of the drawings is similar in many respects to the form shown in Figs. 5 to 8 inclusive and in the said figure the numeral 63 indicates the body of the device corresponding to the body 25, and the numeral 64 indicates one of the number strips corresponding to the strips 29. In this form of the invention, however, these strips are passed over rollers 65 arranged at the ends of the body 63 instead of being passed over the rounded shoulders 28. The face of the body in this form of the invention is covered by a face plate or sheet 66 corresponding to the sheet 32 heretofore described, and abacking plate 6'7v is secured upon the opposite face of the body and is recessed or grooved longitudinally as indicated by the numeral 68 so as to form oppositely located shoulders 69. A small lug or block 70 is secured upon each of the strips 64: and this element of each strip serves to limit the movement of the strip by coming into engagement with the shoulders 69.

Having thus described the invention, what is claimed as new is:

1. In a device of the class described, a housing having sight openings on its face, number members slidably carried by said housing and movable past the sight openings and bearing quantities arranged in numerical order, the housing having slots and bearing aseries of numerical order besi e each slot, the said members and said slots being equal in number to said sight openings, the said members having common means presented beneath said slots to provide for movement of the members in opposite directions, the end walls of said slots being adapted to limit .the movement of the medium employed for moving tion.

2. In housing number housing the said members in either direca device of the class described, a having sight 0 enings on its face, members slida ly carried by the and movable past said sight openuantities arranged in ings and bearing quantities arranged in numerical order, the housing having slots equal in number to said sight openings and said members and bearing a series of quantities arranged in numerical order beside each slot, the said members having common means presented beneath said slots to provide for movement of the members in opposite directions, the endwalls-of said slots being adapted to limit the movement of the medium employed for moving said members in either direction, and'shoulders on said housing to project into each of said slots for limiting the movement in either direction of the medium employed for a distance equal to that required to effect a change from one number to the next adj acent number exposed through the respective sight openings. 1

3. In a device of the class described, a housing having'sight openings on its face and formed with an equal number of slots bearing relation to the sight openings and widened at each end, a number strip for each opening mounted upon said base and slidable past the respective sight opening, each strip having notches of uniform shape in both side edges thereof and having a series of numbers thereon arranged in numerical order and definitely located with relation to said notches, the opposing notched edges of two adjacent strips being exposed within the widened ends of each of said slots.

4. In a device of the class described, a housing having sight openings on its face and formed with an equal number of slots bearing relation to the sight openings and widened at each end, a number strip in the form of an endless band for each opening mounted upon the housing slidable past the respective sight opening, each strip having notches of uniform shape in both side edges and having a series of numbers thereon arranged in numerical order and definitely located with relation to the notches, the opposing notched edges of two adjacent strips being exposed within the widened ends of each of said slots, and a shoulder on said base projecting into each slot near both ends thereof for limiting the move ment of an implement engaging a selected notch in one of said strips and moving in the direction of one of said ends and thence laterally into engagement with one of the notches in the next adjacent strip in the same slot and finally moving in the reverse direction to that of starting.

In testimony whereof I affix my signature.

' HARVEY S. EDMONDSQN. [L.s.]

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2863664 *Apr 29, 1955Dec 9, 1958Jones Lloyd TGame
US2950048 *Jan 6, 1954Aug 23, 1960 Computer for verifying numbers
US2983447 *Sep 24, 1953May 9, 1961Faber Castell A WSlide rule and adding device combination
US2988273 *Sep 6, 1957Jun 13, 1961William Feddick EarlCounter device
US3005586 *Oct 30, 1958Oct 24, 1961 Calculating device
US3114504 *Oct 9, 1961Dec 17, 1963 Percentage calculator
US3416485 *Sep 8, 1966Dec 17, 1968Chester W. PhillipsScoring aid
US3604620 *Apr 23, 1969Sep 14, 1971Rodney S RakesCalculator for different numerical bases
US4056359 *Aug 14, 1975Nov 1, 1977American Home Products CorporationProfile recognition apparatus for identifying bacteria
DE745510C *Sep 8, 1933May 5, 1944 Rechenvorrichtung für Addition und Subtraktion
Classifications
U.S. Classification235/69, 285/69, 235/71.00R
Cooperative ClassificationG06G1/04