US2067068A

US2067068A - Calculator

Info

Publication number: US2067068A
Application number: US698595A
Authority: US
Inventors: Taylor John Leonard
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-11-18
Filing date: 1933-11-18
Publication date: 1937-01-05
Anticipated expiration: 1954-01-05

Description

INVENTOR.

J. L. TAYLOR Jan. 5, 1937.

CALCULATOR Filed Nov, 1B, 1935 4 Sheets-Sheet l J. L j TAYLOR Jan.5,1937.

CALCULATOR Filed Nov. 18, 1933 4 Sheets-Sheet 2 THIS STATONARY DIAL IS Fig. 8 l

Jan. 5, 1937.

J. L. TAYLOR 2,067,068

CALCULATOR Filed Nov. 18, 195s 4 Sheets-Sheet 3 Jan. 5, 1937. i TAYLQR 2,067,068

CALCULATOR Filed Nov. 18, 1955 4 Sheets-Sheet 4 Patented Janj. 5,4 1937 UNITED STATES PATENT` OFFICE 'l Claims.

This invention relates to calculating devices, and an object thereof is to generally improve the construction and operation of devices of this class.`

A further object is to provide a novel method4 oi performing calculations.

A further object is to provide improved apparatus for performing such calculations.

A further object is to provide such an appara- 1o tus involving generally a. plurality of relatively movable scales.

A further object is to provide such an apparatus in which movements of a machine concerning which the calculations are to be madewill,

l at least in part, operate the apparatus to periorm the calculations.

`A further object is to provide a calculator particularly for use in balancing operations.

` A further object is to provide a calculator zo which, given the moment of a force, will calculate the force necessary to produce an' equivalent moment with various convenient lever arms. PA furtherl object is to provide such a device which will express this result in terms. of drill depths necessary to remove an amount of material equivalent to the weight determined.

A further object is to provide a device which will lcalculate drill depths necessary to remove desired amounts of material. 30 A further 'object is to provide such a device which will take into account the conical point of a drill in making such calculations.

A further object is to provide such a devicev which will calculate ounces of @material causing 35 a moment previously indicated in inch ounces. Further objects vand advantages'-wi1l be apparent from the fo1lowing, pecincation and accompanying drawings in w ch:

Fig. 1 isa plan view Ici? a typical installation 40 of my calculating device on a balancing machine. Fig. 2 is a vertical central sectional view of the .same showing the lmanner of actuating the calculating mechanism. v

Fig. 3 is a vertical sectional view of the calcunning mechanism taken on the une :+4 or Figs. 2 and 4.

Fig. 4 is a vertical sectional view on the line.A

4-4 0f Fig. 3.

'50 Fig. 5 is a front elevation certain dials and other parts indicated in Fig. 3.

6- is a sc'tionn view similar to Fig. a showing a modified form of the device.

' Fig. 'l-is a sectional view onthe line 1-1 of 55 Fig.' 6. g Y

(Cl. 23S- 61) culating and indicating directly the amount of material to be removed to balance the piece. Thisgparticular embodiment is to be understood as illustrative merely, and it is to be understood also that nothing in this specification is to be taken in other than an exemplary sense, that other applications of the device are contemplated,

l and Athat the protection afforded by any patent into which this application may mature is not to be taken as limited by the .disclosure of the. de-

scription or drawings, or in fact in any manner except as dened in the annexed4 claims.

The calculating device itself is generically desv9,5

lgnated by vnumeral I, and as shown in the figures it is fixed with the movable carriage 2 of the balancing machine in a position to be readilyl manipulated and read. The balancing machine itself forming the subject matter of a co-pend 30 ing application to Taylor Serial No. 645,675, led December 5, 1932, it will not be described in the present application furthervthan to say that a base 3 4is arranged for mounting upon an ordinary drill press and carries the movable carriage 2 having a fulcrum member 4 on which is balanced a cradle vmember 5 arranged for tilting movement in all directionsl- The machine is arranged with fulcrum 4 directly under the drill spindle, the article to be balanced, or work piece P' being temporarily fixed with this cradle by j appropriate a means whereupon any unbalanee thereof, (the piece P being fixed with its desired .center of mass on the axis of the fulcrum 4) will cause tilting of the `cradle 5, the direction being indicated by a universal level 6.' The heavy portion of the work piece is then swung to a point opposite-a beam 1, and a weight 8 is moved out to a point where the cradle is again indicated by level 8 to be in substantially perfectI balance. 50 A suitable scale then indicates from the position of the weight 8 on the beam 1 the moment of the unbalanced weight in the work piece P. The carriage 2 is now moved out by appropriate' means such as a screw having suitable eon- 55 the amount of drilling necessary, at the point arbitrarily decided upon as suitable, to destroy the moment of the unbalanced force and render the piece in exact balance. This is done by movement of one or more of a plurality of relatively movable dials, the movement thereof being effected either manually or by suitable means such as a cable or other flexible member i3 running from the interior of calculator over a pulley suitably journaled and supported on carriage 2. The cable is fixed, through an adjustable eye bolt I2, with an upstanding flange |3 of base 3 by means of suitable means such as lock nuts |4-|4, through the manipulation of which the relation between base 3 and the internal mechanismof calculator I may be adjusted.

Suitable mechanism is provided for relieving fulcrum 4 of the drilling stresses and other weight when actual balancing is not being done, in the.

present instance a lever l5 actuating a member I6 which acts through suitable cam surfaces I1 and shims I8 to raise bar members i9, vertically slidable in guides 20, and arranged when raised to engage the work piece at either side of cradle 5 to raise the work piece, and to relieve the cradle of unnecessary stress and wear. Suitable mechanism generically designated by numeral 2| is provided to lock the cradle in level position during periods when it is not in use, and to center it accurately on fulcrum 4, and screw members or the like 22, 23, and 24 are provided in the cradle to provide for balancing it before a load is applied. Shims 25 may be interposed between bars I9 and the work piece if desirable.

The calculator itself, as shown particularly in Figs. 3, 4, and 5, comprises generally a pair of

dials

28 and 21, circular in the present instance for convenience and compactness, the dials being enclosed with their operating mechanism in a housing or casing 28 supported on a bracket portion 23 and having a transparent closure 30 to permit observation of the dials while protecting them .from dirt and the like. Dial 26 has a plurality of circular scales thereon corresponding respectively to differentdrill sizes, while dial 21 is provided with similar scales indicating in the present instance moments for diiferent materials. In the embodiment of these figures the dial 21 is movable and it is actuated through the following mechanism. Cable I 0 in the present instance actuates a sheave 3| which carries slidably fixed therewith a cam following member generically designated by numeral 32, the follower cooperating with a cam 33 fixed relatively to casing 28. Follower32.actuates in the present instance through a cord, cable or other flexible member 34 a sheave 35 which actuates dial 21 through a shaft 36 and appropriate connections. The contour chosen for cam 33 accordingly determines the character of movement of dial 21,

which may be any type necessary to perform the4 desired calculations. A pointer or index 31 may be provided to assist in matching the readings vof the two dials, and in the present instance it is carried by a knob 38 by which it may be moved todesired positions.

.glass and housing, for obvious purposes. A

gasket 43 is disposed between knob 38 and closure to exclude dirt while permitting rotation of the knob and pointer.

Sheave as seen in Fig. 3 is iixed with a sleeve or hub portion 44 which is journaled on above mentioned shaft 36, the shaft being supported 'from the housing as willpresently appear. The

sheave is rotated in one direction as indicated in Fig. 4 by a pull on cable l0, while it is urged in the other direction by a spiral spring 45, the spring being fixed at its inner end with a pin or the like 46 fixed with sheave 3| and suitably fixed with housing 28 at its outer end with a pin 41. The spring is in the present instance guided about a plurality of pins 4B arranged to prevent encroachment of the spring upon the region adjacent to the middle portion of sheave 3|. Any other suitable means for yieldingly opposing the rotation of sheave 3| may be employed within the contemplation of the invention.

Cam follower 32 in the present instance comprises a roller 49 journaled on a pin 50 which is fixed With a member 5|. Member 5| is disposed in slidable relation with sheave 3l, and is so maintained by a slide member 52 as more particularly shown in Fig. 9, the members having interlocking portions 53 and 54 which'prevent separation of member 5| from sheave 3| while permitting sliding movement thereof in the direction of member 52. Member 52 is fixed with the sheave by suitable means such as screws 55. Cable 34 is suitably fixed with member 5|, as by introducing it into a bore in the member and fastening it in any well known manner at 56. It then extends in a direction substantially parallel to the direction of movement of member 5|, and around sheave 35, being fastened at its other end to a coil spring 51. which for convenience and to secure extra length and exibility is in the present instance passed around a pulley 58 journaled on a pin or the like 59 xed with sheave 3|, the spring thus being doubled on itself, and fastened at Aits end remote from cable 34 to a pin or the like 60, also fixed with sheave 3|. To provide for a positive mathematically accurate drive for sheave 35, cable 34 is permanently fixed therewith at 6| by any suitable means, in the present instance the cable being sharply bent or kinked by passing through a pair of closely spaced holes in the periphery of the sheave. Sliding movement of the member 5| will thus cause rotation of sheave 35 relatively to sheave 3|, the direction and amount thereof being determined by the contour of cam 33, the pull of spring 51 on cable 34 maintaining roller 49 continuously against the surface of the cam. i

Cam 33 is stationary in the present instance, being supported vby or from aplate or closure 62 fixed in housing 28 and carrying dial 26, the plate being arranged in a bore 83 in the housing and maintained therein by any suitable means such for example as screws 64. Cam 33 is fixed with plate 62 in the present instance by screws 65.

Shaft 36 is suitably journaled at one end in sleeve or bushing 66 which is fixed in a bore 61 in housing 28, the other end being supported in a bushing 68 which is in turn supported in aligned bores in plate 62 land cam 33. Sheave 35 is suitably fixed with shaft 36 as by means of a key 89, and dial 21 may beiixed therewith in various relations by the following means:

A bushing 18 is journaled on the exterior of sleeve 68, and is fixed with dial 21 by means of a flange 1I, the bushing extending forwardly beyond the front margin of sleeve 88 and embracing a reduced portion 12 of shaft 36.` For readily' turning the bushing 18 a knob 13 is slidably journaled on extension 12 and connectedwith the bushing by suitable means such as keys 14 fixed. with the bushing and engaging keyways 15 in the knob. A lock nut 16 is threaded on the extension 12 of shaft 36 and has a hub portion 11 extending in thepresent instance into a recess 16 in knob 13, the nut seating in the bottom of the recess when tightened, and forcing it and bushing 18 to the right as seen in Fig. 3. The bushing seats against the shoulder formed between the extension 12 and the remainder of the shaft, and is clamped therewithso as to respond accurately to movements of the mechanism. By loosening lock nut 16 dial 21 may be manually adj-usted from knob 13, the dial then being locked with the shaft by-tightening the nut again, for operation through the mechanism.

In order to insure a positive drive to sheave 3i,

. cable l is xed with the sheave as shown in Fig. 4, at 18, the cable being in the present instance bent sharply or kinked by-passing into and out of closely spaced holes in the periphery of the`sheave, and fastened at its end if desired by any suitable means. Obviously other means than cables and sheaves could be used within the contemplation of the invention to secure rotative from linear movement and it is understood that any such well known means may be resorted to without departing from the scope and spirit of the invention. Furthermore it isl contemplated that actuating mechanism may be omitted under certain conditions and the dials operated entirely by hand without departing from the invention.

Pointer 31 may be rotated by knob 38. which as shown is journaled on the exterior of bushing 18. As seen in Fig. 5, the pointer in the present instance is of a substantially transparent substance, so that the scales thereunder are always entirely visible, the pointer having a hair line 88 marked thereon by means of which the scales may be readily compared and read, although of i course any pointer which would permit comparison of the cooperating scales would fall "within the scope of the present disclosure.

In considering the operation of the device it will be understood that, given the moment of the unbalanced weight present in the workpiece P, and the radius on which it .is found, both of which values are readily determined by the balancing machine "above described, it would be possible to determine mathematically, after choosing a suitable place to drill, the weight of material which should be removed at that point to equal the moment ofthe unbalanced weight, and accordingly to accurately balance the piece. The unknown volume of material equivalent to this weight could then be determined by dividing this result by the weight, of a unit volume, for example a cubic inch of the material of the work piece. A convenient size of drill could then be chosen and the depth necessary to remove this volume of material could be determined' by nguring the cross sectional area of the drill and dividing the volume above determined by this area. A suitable correction would have to be made for the conical or point portion of the drill, which would give a non-uniform variation to the depth determined for uniformly varying volumes up to the.

point where the conical portion is entirely within \the work piece, after which the volume of the point would have to be added in each case to the uniformly varying depth determined for the cylindrical portion of the drill. These calculations would be time consuming, and fraught with the possibility of error, and the use of the present calculator accordingly constitutes a material advance in the art, since it positively and immediately performs these calculations and permits direct reading of the desired result, namely the depth to be drilled, without calculations on the part of the operator and without errors which would be apt to enter into such calculations.

Thus in the embodiment illustrated, it is only necessary to run the carriage 2 out to a convenient point to drill, read on the scale on dial 21 corresponding to the material of the work piece, the moment of unbalance as determined by the weight k8, and read opposite this value on the scale on dial 26 corresponding to the size of drill selected, the depth necessary for that size drill to remove the unbalanced weight. The dial 21 will I have moved a distance determined by the movement of carriage 2 and the contour of cam 33, which takes into account the difference in weight required at different distances from the center.

to equal a given moment, and the other factors in the several calculations are accounted for in the spacing of the various scale divisions. In the embodiment shown in Fig. the materials are designated on the pointer 31 over their respective scales as shown, while the drill sizes are also marked on the pointer over their respective scales.

The invention is not limited to the specific spacing or arrangement of scales herein shown, but embraces other arrangements wherein the general idea may be applicable.

For checking the accuracy of the apparatus, an index point 8| is provided on dial 21, which is arranged to register with a similar point 82 on dial 26 at such time, as the fulcrum l is directly under Athe drill spindle, andas La further check, a pointer 83 Fig. 1 is fixed with base 3 and has an index 8l arranged to register witha mark 85 on a suitable portion of carriage 2. The

points 8l and 82 should register at the same time as index 84 and mark 85, and once base 3 is accurately located on the drill press it is unnecessary to check with the drill spindle when it is desired to check the balancing machine, but merely to locate the carriage by

points

84 and 85, and note whether 8| and 82 correspond. If there has been any Wear or elongation of the cables, correction can be made by nuts i4 and l5, or by shifting dial 21 relatively to shaft 36 in the manner above explained.

. Various modifications of 4the above structure might be made within the scope of the present invention, and as a typical example the dial shown in Fig. 8 is included. In this arrangement the outer dial is identical Iwith, dial 26 of Fig. 5, and itis accordingly designated by the same reference character. 'I'here are, however, a plurality of inner dials. Thus a dial 86 is movable from mechanismoperated from movement of carriage 2 and represents density or materials. Adjacent 75 to this is a dial 81 which represents moments in a manner similar to dial 21 above, and may be set by hand and locked with dial 88 in any desired relation, and adjacent to dial 81 is a dial 88 which is also arranged to be set by hand.

In this embodiment the manipulation is similar to that of the arrangement just described except that the dial 81 is first adjusted so that an index point 89 is opposite the weight per unit volume of the material being balanced as represented on dial 86, the reading then being taken between the scale on the moment indicating dial 01 and one of those on dial 26. The arrangement of Fig. 8 is in general more adaptable for relatively large work pieces, and dial 88 is for use where the size or other characteristics of a piece makes desirable the drilling of severaln holes rather than a single one. The desired number of holes on dial 88 is set opposite the moment as read on dial 81 and the depth of any one hole is then read opposite the l of dial 88 on dial 26. The moment as read on dial 81 may be converted into weight by letting dial 88 represent the radius A of the work piece at which point it may be desired to add material, as would be required for example on the light side of a fan. Dial 88 carries a scale 86a corresponding to that on dial 81 for use when automatic operation is not desired.

In the present instance in order to give the apparatus a greater range of movement, partic ularly for use with relatively large work pieces, the embodiment of Fig. 8 is provided with a somewhat different arrangement of driving mechanism than that previously described. As seen in Figs. 6 and 7 the cable I0 engages a sheave which is provided with a plurality of grooves 9| or otherwise arranged so that the cable may take a plurality of turns around the sheave, and thereby have a greater range of movement than would be possible with a single turn. Sheave 90 drives, through a reduction gear generically designated by numeral 92, a shaft 93 which in turn rotates a carrier plate 94 carrying a cam follower generically designated by numeral cooperating with a cam 96 and operating through a. cable 91 to drive a sheave 98 fixed with a shaft 99. Shaft 99 drives dial 86 through appropriate connections described below.

Returning to the specific details of construction, the whole is enclosed in a housing 28 substantially identical with the housing of Fig. 3, having a similar bracket portion 29, the housing being provided with a transparent closure or glass 30 maintained in place by a ring 39 etc., in a manner similar to the previously described structure. Sheave 90 is journaled on shaft 93 which is supported at one end in a bushing |00 fixed in a suitable bore in a portion of housing 28, and at the other end in a suitable bore in sheave 98. Reduction gear 92 comprises a gear |0| fixed on a hub portion |82 of sheave 90 by suitable means such as a pin |03 and driving a gear |04 fixedl with a shaft |05 which is rotatively supported in a bushing |05 fixed in a bore |01 in housing 28. Shaft |05 has a gear |08 fixed therewith which drives a gear |09 which is fixed with above mentioned shaft 93 by appropriate means such as a key |090. The sizes of the various gears are such in the present instance that shaft 93 is driven at a substantialhr slower rate than sheave 90, and accordingly a much greater travel of the carriage 2 of the machine may be had than in the previously described construction, the scales on the several dials being graduated in keeping with the different rate of travel of the carriage relatively to the dials. Obviously other ratios could be used in the gearing which would increase rather than reduce the travel of the dials if desired. such construction being better adapted for use in balancing small articles or for any purpose where an increase in the rate of the dials is desirable.

Rotation of sheave 90 is opposed by a spiral spring I In which is coiled in the present instance about a series of pins fixed with the sheave. the inner end of the spring being fastened by a pin ||2 to the sheave, while the outer end is fixed with housing 28 by means of a pin ||3. The spring works in a similar manner to spring 45 above described.

Shaft 93 has a flange ||4 which may be fixed with carrier plate 94 by suitable means such as rivets 5, and a bushing IIB may be interposed between sheave 90 and shaft 93 if found desirable.

Follower 95 is similar to above described follower 32 comprising a roller |1 journaled on a pin ||8 fixed with a member |9 which is slidably associated with carrier plate 94, a slide |20 fixed with the plate by screws or the like |2| serving to maintain the member in position. Cable 91 is passed through a suitable bore in member I9 and fastened at |22, the cable passing over sheave 98 and being connected to a spring |23 which passes around a pulley |24 journaled on a pin or the like |25 fixed with carrier plate 94, the spring then passing to a pin |26 also fixed with the plate and being fastened thereto whereby to exert a continuous pull on the cable. Cable 91, where it passes over sheave 98 is positively fixed therewith by any suitablemeans, in the present in` stance by being sharply bent for entering a pair of closely spaced holes at |21, a positive relation being thereby established between follower ||8 and shaft 99, although of course other methods might be used for forming such a positive connection without departing from the present invention.

Shaft 99 is supported for rotation in a bushing |28 carried by cam 96 which is stationary and supported from a dial plate |29 which is supported in housing 28 and carries dial 28. Plate |2 9 is fastened therein by suitable means such as screws |30, while cam 96 is fastened in the present instance to plate |29 by screws |3|. Shaft 93 as shown is separate from shaft 99 and is guided and supported in a suitable bore ln sheave 98.

Shaft 99 has a forwardly extending portion |32 reduced in diameter and carrying a bushing or sleeve |33 which extends rearwardly over bushing |28, clearing the front end thereof and seating .against the shoulder formed between reduced extension |32 and the remainder of shaft 99. Sleeve |33 has a flange portion |34 to which is fixed a disk |35, the peripheral offset side of which constitutes dial 86. Sleeve |33 is connected by means of a key |36 with a knob 'or grip member |31 slidably journaled on extension |32 of shaft 99, and provided with a keyway |38 engaging key |38. Bushing |33 and accordingly dial 86 can thus be turned by manipulating grip |31. A lock nut |39 threaded on extension |32 may be used to force grip |31 and sleeve |33 back against the above mentioned shoulder between shaft 99 and extension |32 to clamp these parts rigidly together whereupon dial 86 is positively driven from the mechanism in housing 28.

being transparent in the present case and having a hair line |50 thereon (Fig. 8) for readily matching the scale divisions. A suitable gasket |5| is provided where knob f49 enters the glass or closure 30 to exclude dirt and the like.

In order to provide a certain amount of frictional resistance to the movementl of certain of the members, a spring |52 seated in a suitable groove in sleeve |40 presses outwardly against the inner surface of sleeve |45, the spring being of non-circular form whereby to press at the same time inwardly against the -groove in sleeve |40.

. The sleeve |45 is'accordingly yieldingly carried by sleeve and not apt to be accidentally displaced from a desired relation with sleeve |40. A similar spring |53 isseated in a groove in sleeve |45 and serves a similar purpose with relation to knob |48. Obviously other means might be employed for detaining these parts in desired positions without departing from the invention.

The mode of operation of the device will be apparent from the foregoing description, the several dials being controlled from the several grips in the manner explained in connection with Fig. 8. Thus diall 86 may be corrected in its relation with the mechanism by loosening nut |39 and turning knob l |31 until the correct position is obtained. The dial may then be clamped-in this relation by tightening nut |38. Dial 81 may be set in relation to dial 88 by loosening nut |43 and operating the dial manually by means of grip |42,

after which the two dials may be locked together by again tightening the nut. Operation of the mechanism then turns both

dials

86 and 81, and movement of dial 88 and pointer 48 may be effected by manipulation of knobs |46 and |49 respectively.

If desired the calculato-r may be simplified by i omitting the driving mechanism and operating the dials by hand through the knobs 13, |43, etc.,

l the correct amount of movement of the scales being determined from the scales themselves.

The scale divisions'on 'dial 21 designated as iron are laid out proportionally to the logarithms of various moments, and those on dial .26 are proportional, except for a correction noted below, to the logarithms of various volumes of cast iron equivalent to weights in ounces corresponding to the moments represented on dial 21 at a lever arm or distance of one inch, and index 82 is placed at the point on dial 26 representing the logarithm of a volume of cast iron which weighs one ounce. If the moment of the unbalanced weight should be for example 5 inchounces, obviously one ounce would need to be removed at a lever arm of 5 inches, or five ounces at a lever arm of one inch to render the work piece incorrect balance. At the point marked by index 82 one ounce is removed by drilling to the depth indicated, and if the moment of five inch-ounces on the iron scale is placed opposite the index it may also represent the lever arm'distance, or five inches, the correct distance for balancing the piece by removing one ounce. Moments and distances may therefore both be read on this scale, and the dial accurately set by hand without resort to mechanism if desired. With the correct setting for dial 21 established in this manner, the drill depth may be read opposite the moment as in the case of the automatically operated embodiment.

Assuming a moment as obtained from the weighing apparatus to be 3v inch-ounces, and a convenient lever arm for drilling to be six inches, the material being cast iron; at a lever arm of ,three inches the amount to be removed would be one ounce as before, represented by the positionof index 82. If a desirable lever arm is six inches; however, the amount to be removed at this distance is less thanl one ounce, or exactly half what it would be at the three inch distance. The weight necessary to be removed is thus inversely proportional to the distance chosen, and it is necessary to divide the amount or weight indicated on scale 26 by the ratio between the lever arm corresponding to an effective weight of one ounce, and the desired lever arm. Such calculations are .readily performed on the illustrated logarithmic scales, and in the present instance the desired lever arm value of 6 would be set opposite the index 82, or one ounce position, and the moment read at 3 on the same scale on which the lever arm was read. The weight to be removed would then be found opposite the 3 on any scale on dial 26, and if the scale was identical with the iron scale, the weight would be .5 ounce, and this amount is indicated on any scale on dial 26, but in terms of drill depths instead of ounces. Taking any convenient drill size, however, Vit will be observed that the depth opposite moment 3 is not exactly half that opposite distance 6 with the above set up, but is slightly more than half. 'I'his seeming inaccuracy is caused by the distortion of the scales on dial 26 above explained to compensate for the volume of the conical portion or point of the drill, which represents a larger proportion of the total volume of the bore at the lesser depths than it does at the greater.v A greater depth of drilling is therefore required to remove half a given volume than half the depth required to remove the whole volume. f

Dial 21 may accordingly be set for any convenient drilling point by merely setting the lever arm represented thereby on the iron scale opposite index 82, and the mechanism for automatic movement thereof eliminated. l

If the material being balanced is not cast iron, the lever arm is set up as before on the iron scale opposite index 82, but the moment is read on the appropriate scale such as stee aluminum etc., and the depth found on dial 26 as in the case of automatic operation, the setting using the iron scale merely duplicating the movement of the dial which would take place automatically upon movement of the carriage ofy the machine in the more complicated models.

In the embodiment of Fig. 8, a similar 'operation is possible, the lever arm being read on scale 86a, and set opposite index 82, after which the moment is read on scale 81, the latter having first been positioned properly relatively to scale B6 for the material being operated upon.

The above being a complete disclosure of an illustrative embodiment of the invention, what is claimed as new, and desired to be secured by Letters Patent of the United States is:

1. In a calculating device the combination of a pair of concentric, circular dials, one of said dials being rotatable relatively to the other, said dials having spaced divisions thereon, the spaces being proportional to varying values to be calculated, means for moving one of said dials including a stationary cam member, a carrier member, and a relatively movable follower member carried by said carrier member, said follower member being arranged to be caused by said cam to slide on said carrier member so 'as to move in an orbit about the axis of said dials, and connections from said follower for rotating said rotatable dial.

2. In a calculating device the combination of a pair of concentric, circular dials, one of said dials being rotatable relatively to the other, said dials having spaced divisions thereon, the spaces being proportional to varying values to be calculated, and mechanism for driving said movable ldial including a rotative driving member supported axially of said dials, a cam follower slidably supported on said driving member, and a cam-fixedly supported axially of said dials and in a position to contact said cam follower, said cam being shaped to guide said follower to slide on said driving member and to move in an orbit about said dials and said driving member, and actuating connections from said follower to said movable dial and arranged to rotate said movable dial.

3. In a calculating device the combinationof a casing, a pair of concentric, circular dials, one of said dials being rotatable relatively to the other, said dials having spaced divisions thereon, the spaces being proportional to varying values to be calculated, a rotative driving member supported in saidcasing axially of said dials, and a rotative carrier member also supported in said casing axially of said dials, speed rate changing means in said casing for driving said-carrier from said driving member at a different speed from said driving member, a cam follower slidably supported on said carrier member, a cam fixedly supported in said casing axially of said dials and in a position to contact said cam follower, said cam being shaped to guide said follower in an orbit about the axis of said dials and said driving member, and actuating connections from said follower to said rotatable dial and arranged to rotate said rotatable dial when said driving member is rotated.

4. In a calculator the combination of a pair of juxtaposed concentric circular scales, a rotative shaft supporting one of said scales, and a rst sheave on said shaft, driving means for said sheave including a second sheave coaxial with said first sheave and axially spaced therefrom, a slidable member supported on said second sheave, a cam fixedly supported adjacent said first sheave, follower means on said slidable member disposed to engage said cam, resilient means supported on said second sheave and operative to maintain said follower means in contact with said cam, and including a flexible member extending from said slidable member to said first sheave and engaging said first sheave.

5. In a calculator drive a rotative shaft, a first sheave on said shaft, driving means for said sheave including a carrier sheave member, and a slidable member supported thereon, means for sliding said slidable member, a cable extending from said slidable member about said sheave, and means for tensioning said cable including a second sheave journaled on said carrier sheave, adjacent an edge thereof, and a tension spring fixed to said cable, running over said second sheave, and having an end portion anchored to said carrier sheave at a point spaced from said second sheave.

6. In a calculator for actuation by movements of a balancing machine the combination of a stationary dial, and a movable dial, a rotative shaft connected to move said movable dial, and a first sheave on said shaft, driving means for said sheave including a second sheave coaxial with said rst sheave, and axially spaced therefrom, a slidable member supported on said second sheave, a cam fixedly supported adjacent said first sheave, follower means on said slidable member disposed to engage said cam, resilient means supported on said second sheave and arranged to maintain said follower means in contact with said cam and including a cable connected with said slidable mem,- ber and engaging said first sheave, and a cable engaged with said second sheave and leading to said balancing machine for actuating said calculator.

7. In a calculator drive a driven shaft, and a housing in which said shaft is journaled, a first sheave fixed on said shaft, a second sheave journaled on said shaft, a cam follower slidably carried by said second sheave, and arranged for sliding movement relatively thereto in a direction parallel to a radius of said sheave, a cable running oiI of said first sheave in a direction parallel to a radius of said first sheave and fastened to said cam follower, means for resiliently urging said first sheave in a direction to tension said cable, and a stationary cam positioned to contact said cam follower and to shift it on said second sheave for modifying the movement imparted to said first sheave by said second sheave, and means for rotating said second sheave.

JOHN' L. TAYLOR.