US2174665A

US2174665A - Balancing machine

Info

Publication number: US2174665A
Application number: US77542A
Authority: US
Inventors: Stanley D Livingston
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-02-27
Filing date: 1936-05-02
Publication date: 1939-10-03
Anticipated expiration: 1956-10-03

Description

. Oct-3,1939. v s. D LIVINGSTON 4,

BALANCING MACHINE Original Filed Feb. 27, 1930' 4 Sheets-Sheet 1 v INVENTOR Y 5' i 1 ATTORNEY as v 3: gnm am s. D. LlVlNGSTON 2,174,665

BALANCING MACHINE Gen 3, 1939.

Original Fild Feb. 27, 1930 4 Sheets-Sheet 2 INVENTOR d ,9

' 2- 7 ATTORNEY 5 3, 1939- v s. D. LIVINGS-TON 2, 174,665

BALANC ING MACHINE Original Filed Feb. 27, 950 4 Sfiegts-Sheet s INVENOR TTO Get. 3,. 1939.

- BALANCING MACHINE br i mal Filed Feb. 27, 1930 4 sh et -sheet 4 INVENTOR "t. 3 BY 5. ATTORNE s. D. LIVINGSTON 2,174,665 7 Patented Oct. 3 1939 UNITED STATES PATENT OFFICE nsmome mourns Stanley 1). Livingston, Freeport, N. Y. Original application February 2'1, 1930, Serial Divided and this'applicatlon May a 2. 1930, Serial No. 17.542

10 Claims. (01. 73-51) 'This invention relates to a machine for obtaining facts quantitatively determinative of the mass change necessary' in a body to balance it while rotating.

Vibration in a machine is often caused by an unbalance in a rotor therein. This unbalance is due to unequilibrated centrifugal forces generated in the rotor. The unbalanced centrifugal force may act only radially from the axisof rotation and substantially uniformly along that axis. This condition is known as pure static un-= balance. latory motion ofthe axis of rotation of the rotor to a new position parallel to its initial position.

' The unbalanced centrifugal forces may,act only at a rightangle to a longitudinal line drawn through the center'of mass of the body, and'be equal in opposite directions, that is, additive in eflect, on both sides oi the center. This unbalance is known as pure dynamic unbalance. Pure dynamic unbalance causes a pivoting of the axis of rotation upon an axis at a right angle thereto and positioned intermediate the ends of the body.

A body rotatable upon a longitudinal axis is perhaps seldom encountered which is in unbalance due to either pure static or pure dynamic unbalance. If the major efiect of the unbalance makes it appear as though the body were statically unbalanced there is almost always an effeet which makes it appear that the body is dynamically unbalanced. This probably generally arises from the fact that the mass causing what appears to be a major effect of static unbalance does notlie exactly in the transverse plane of the center of gravity or mass of the body. When the major eflect is as though the body were dynamically unbalanced there is also. generally an effect which makes it appear that the bodyis statically unbalanced. This generally arises from the fact that the unbalanced centrifugal forces are not exactly equal and opposite on both sides of the axis of rotation. This excess of mass on one sideof the axis of rotation Pure static unbalance causes a transan axis at aright balance has perhaps, unfortunately, become known as dynamic unbalance.

The word alpha as used in this specification,

-defines that component of unbalance in a body which tends to make the body oscillate only about 6 an axis parallel to its axis of rotation when rotated about its longitudinal aids and so supported thatit may oscillate as a whole, which oscillation is caused by a static unbalance.

-The word beta as used in this specification, v10 defines that component of unbalance in a body which tends to make the body oscillate only about angle to its axis of rotation when rotated about its longitudinal axis andso supported. that it may oscillate as a whole, which 15 oscillation may be caused either -by a static or a dynamic unbalance or by a combination of both.

Alpha. and beta components together define the tendency other than the actual axis of rotation.

Magnitudes corresponding to these two difi'er- 4 out tendencies completely define values of masses which must be added to the body to completely correct the tendencies.

Correction for unbalance requires subjection ofthe rotor to tests which indicate the necessary I mass change in the rotor.

A principal object of applicant's invention is the provision of a machine by which the magnitude of the alpha component and the magnitude of the beta component, may be ascertained by tests applied to the rotor, and then may be assigned, as a matter of computation, to'such positions on the rotor thatreither one ii actually ap-. 86

plied would not interfere with the inherent unbalance in the rotor due -to the other.

Another object of the invention is the provision of a machine-bywhich magnitudes, one representing the alpha component the other the beta 40 component, are obtained which are assigned, as

' a matter of computation, in such a way, that the computation of the magnitude of a single mass change as a resultant in a given plane is facilitated,

A further object of the invention is to provide machine whereby magnitudes are obtained whereby'the computation to assign the proper position of portions of the alpha magnitude and portions of beta magnitude is simplified.

A further obiect oi the invention is the provision of a'machine by which the general unbalance may be ascertained as two numerical quantities,

one of which may be considered alpha unbalance,

' that is, one component of unbalance; and the '55 of a body tov rotate about an 20.

sion of a machine which preferably,

2 other may be considered as beta unbalance, that is, another component of unbalance. A furtherv object of the invention or-mechanical manipulation to separate the efcorrections fects ofthe two kinds of unbalance.

Other objects and advantages of the invention will appear as the description of a particular physical embodiment of machine proceeds, and the novel features of the invention will beparticularly pointed out in the appended claims.

The fundamental discovery, cants machine is that correction for alphanubalance may be so applied that it will have no efiect upon the body, and correction for beta unbalance may be so applied that it will have no effect upon the inherent beta unbalance of .the body to thus practically and conveniently apply those they'must be distributed in at least two transverse planes of the body, one on each side of the vertical plane. containing the axis by which the beta component of unbalance is obtained. The correction for alpha unbalance must be applied all on one side of the longitudinal axis of rotation and distributed between the planes so as to generate centrifugal forces which collectively are equal and opposite to the inherent alpha unbalance and also so as to generate centrifugal forces balanced about the beta axis.- The correction for beta unbalance must be applied on opposite radii from the longitudinal axis of rotation, partly on each side of the vertical plane through the beta axis of a magnitude and position, as regards the beta axis so as to produce a couple of centrifugal forces equal and opposite in effect to the .couple which causes the beta unbalance, and also so as to generate equal and opposite centrifugal forces about the longitudinal axis of rotation. A

Applicant's invention is characterized by a principle which requires restrained oscillation of the rotor on each of two axes. One of the axes is parallel to the axis of rotation of the rotor. Oscillation on this axis ascertains the numerical quantity determinative of the alpha unbalance. The other oscillation axis is at a right angle to the first and lies in a plane transverse to the longitudinal axis of rotation of the rotor. Oscillation on this last mentioned axis ascertains the numerical quantity which is determinative of the beta unbalance of the rotor.

It is to be observed that applicant has not narrowed the specification of the axes, in that, the axis employed to obtain the alpha component has not been specified as necessarilylying in a vertical plane passing through the axis of rotation of the rotor, because such axis may correspond to and take all positions of the generatrix of a right cylinder, the axis ofwhich coincides with the longitudinal axis of rotation of the body; and the axis associated with the beta component has not been specified as necessarily lying in the-vertical plane cutting the longitudinal axis of rotation and midway of the body, because it is evident, that this axis may lie anywhere in any vertical plane, transverse to the axis of rotation of the rotor between the planes of correction.

Applicant's invention is further characterized by a principle which requires that the mass change ascertained from the numerical quantity,

determinative of the alpha unbalance shall be the basis of appli inherent beta unbalance-"of a nd in order distributed or assigned in such manner that the resulting mass change in the rotor=will have no effect upon the beta unbalance already existing therein. This requirement necessitates applying the correction mass for the alpha unbalance all on one side of the longitudinal axis of rotation of the body and in at least two planes, one on each side of the longitudinal center of the body.

It further requires that the amount on one side .of the axis by which the beta magnitude is ascertained shall be proportioned so that it will generate a moment about that axis equal to the moment generated by the amount on the other side and opposite in effect. This requirement of equal moments generally necessitates a knowledge as to the distance of each correction plane from the axis, that is, the axis at a right angle to the longitudinal axis of rotation of the body, upon which the body oscillates when the numerical quantity determinative of the beta unbalance is being ascertained, although it is not to be understood by this statement, that one must necessarily know as a numerical quantity the linear distance of the correction plane from the axis, because by calibrating a given machine employing a given rotor with known unbalance therein a ratio may be ascertained which will equal the ratio of the linear distances, if they were known.

It'is evident, then, that in order not to disturb beta unbalance when correcting for alpha unbalance, the correction mass applied by applicant must be applied all on one side of the longitudinal axis of rotation and in a numerical amount equal to the numerical value of the alpha unbalshoe but in each correction plane inversely as the distance of that correction plane from the axis upon which the body oscillates when the numerical quantity determinative of beta unbalance is ascertained, and so as to generate equal moments about the beta axis.

Applicant's invention further requires that the correction applied for beta unbalance shall be applied to the body in such a way that it will not disturb alpha unbalance. This requires that the mass change necessary for correction for beta unbalance shall be divided between at least two planes one on each side of the beta axis. and the masses 180 degrees apart as regards angular rotation in a'plane transverse to the longitudinal axis of rotation, and positioned so that equal and opposite centrifugal forces about the longitudinal axis of rotation are generated.

Correction for beta unbalance may be made in any two transverse planes of the rotor but if it is not made in the same planes in which the correction for alpha unbalance is made the absolute magnitude must be altered so that it will generate the same moments, as it would have generated if it had been placed in those planes, about a given point, that is, the point of intersection of the longitudinal axis of rotation with the transverse vertical plane passing through the axis upon which the oscillation took place for determining the beta correction, that is, in all cases it must generate a couple of centrifugal forces equal and opposite to the couple of centrifugal forces causing beta unbalance.

If correction for alpha unbalance is to be made in one pair of planes and correction for beta unbalance in another pair of planes the general sum of zero turning moments, about the axis 76 by which: the beta magnitude is ascertained for the body; and the correction for beta unbalance will generate equal centrifugal directed from the longitudinal axis of rotation and separated angularly 180 degrees in a plane transverse to the longitudinal axis of rotation.

. At the same time the correction for alpha. un-

balance will generate a resultant centrifugal force equal and opposite to the unbalanced centrifugal force causing the alpha unbalance and the correction for the beta unbalance will generate centrifugal forces forming forces equal and op posite, that is, forming an algebraic sum of zero with the couple formed by the centrifugal forces causing beta unbalance. A further characteristic of applicant's invention is that a numerical quantity determinative of alpha unbalance may be indicated by a proper machine simultaneously with an indication of a numerical quantity determinative of the correc-" tion to be made for beta unbalance, that is, the oscillation from which the alpha. correction is ascertained, ascertains the numerical quantity determinative of the correction for alpha unbalance, even it simultaneously anoscillation is taking place at an angle thereto which is determinative of the correction to be made beta unbalance and vice versa. No correction whatsoever needs to be made in the correction planes until after the values for all corrections to be made have been ascertained, although if desired, alpha correction may be made and the beta magnitude ascertained. Erom this it follows, that if the corrections have been ascertained for both alpha and for beta unbalance, it willfrequently occur'that the correction for one kind of unbalance may be partially or fully cancelled by correction for the other; consequently both corrections may be efiected by a single addition or subtraction of mass at one point in a particular plane and a single addition or subtraction of mass at a particular point in another plane.

\ As an embodiment of machine, applicant contemplates one in which the axis of oscillation, from which the numerical quantity determinative of the beta unbalance is obtained-will be in a transverse plane between a pair of planes in which correction for both alpha and beta unbalance is to be made. In case there are a plurality of pairs of correction planes, the position of the beta axis would'be between the planes considered as pairs, that is, as many planes on one side as on the other.

The preferred embodiment would have the axis in a median plane to each pair. The ratiohereinbefore mentioned then becomes 1:1, so that after the numerical magnitude for correction for alpha unbalance has been ascertained it may be halved and one half applied in each correction plane, where there is a single pair, and the numerical quantity determinative of correction for beta unbalance may behalved and a halfplaced in each plane. If more than one pair of planes are used in which to makecorrection then the mass may be distributed equally in. an amount determined by dividing the total mass change into as many equal parts as there are correction planes and applying one part in each plane. The correction for beta unbalance will be applied one half on one side of the longitudinal axis of rotation and the other half on the other side-and could be distributed amongst those planes on one side of the median transverse plane in a ratio which would develop therein moments about the center axis used in determining the beta unforces radiallyof the axis.

y 3 balance of the rotor equal numerically to the turning moments generated by the distribution made in the correction planes on the other side The simplest and most convenient and preferred embodiment of amachine, where rotors of substantial length in proportion to their diameter are to be balanced, is to select two correction-planes, position the beta axis midway between those planes and apply correction both for alpha and betaunbalance in these two planes.

As the essential point of novelty in the machine of applicant's invention is directedparticularly to determining the numerical value of corrections to bemade, the transverse planes in which they are to be made, the position of the correction mass in one plane as compared to that in the other, and the position of the alpha correction as regards the beta in a given plane, further data is needed to enable thedetermination of a resultant single mass change a and its exact position in each plane.

The further data needed is the position of the high point" and the angle of lag. These are bothwell known and understood facts and both maybe obtained by means which are old and well known. The high point and the angle of lag having been ascertained, the numerical quantities obtained bythe oscillations caused by alpha unbalance and by beta unbalance are combined therewith as a matterof computation or graphically. The result of the method 0f treatment, whatever it may be, is that, in general, a single mass change for each of the correction planes is ascertained and its exact position in these planes as regards angular rotations about the longitudinal axis and radial distance therefrom. This change, when made, corrects unbalance in the rotor so that the rotor is then balanced both statically and dynamically.

Applicant's machine, as lierein described, serves to determine numerical quantitative values which are usable together with other data such as the position of the high point and the angle of lag of the' high point by which to determine by means of computation -.or graphical-1y, as by a with means to permit oscillation about two axes,

one of which is parallel to the axis of rotation of the body and the other of which is perpendicular to the axis of rotation, the unbalanced -forcespresent in the body may be divided into two components, which are designated as thealpha component and.the beta component respectively, and the .beta component may be caused by a static unbalance or a dynamic undynamic unbalance. The alpha component is that part of the unbalance as a whole which causes the body to oscillate only about the axis parallel to the axis of rotation, and the beta component'is that part of the unbalance as a whole which causes the body to oscillate only balance or a combination of both static and I alpha of Fig. 3, viewed in the about the axis perpendicular to the axis of rotation.

After the magnitudes of the alpha and beta components have been determined and the value.

equal to the mass change that is necessary at each end to produce balance regardless of the means used to determine the necessary correction for unbalance. Therefore, if desired, the

be combined vectorially and a single mass change made on each end that will compensate for both the alhpa and beta components.

. In describing the invention, reference will be had to a particular physical embodiment of the machine and to the .drawings thereof accompanying this specification, wherein like characters of reference designate like parts throughout the several views, and in which:

.Figure 1 is a front elevational view of a device embodying the main principles of applicant's invention; Fig. 2 is a side elevational view of the device as shown by right hand side as shown in Fig. 1; Fig. 3 is a sectional elevational view on the plane indicated by the line III-III, of Fig. 2, viewed in the direction of the arrows at theends of the line; Fig. 4 is atop plan view of the device as shown by Fig. 1; Fig. 5 is a cross-sectional elevational view on the planes indicated by the lines V-V at the ends of the lines; Fig. 6 is a cross-sectional elevational view on the planes indicated by the lines VI-,-V I of Fig. 5, viewed in the direction of the arrows at the ends oi the line; Fig. '7 is a cross-sectional view on the plane indicated by the line VII-VII of Fig. 6, viewed in the direction of the arrows at the ends of the line; Fig. 8 is an electric circuit and device included therein th the invention; Figs. 9 and ing the mathematical relations underlying the inventionpFigs. 11 and 12 are views .of the left hand end and the right hand end respectively of the body shown 'by- Fig. 10 aftercorrection weights have been applied in the manner hereinafter described. I

. Broadly speaking, the particular physical embodiment selected by applicant to illustrate the. principle of his invention, and illustrated in the drawings, includes'1., ,anelectric motor. designated generally by M, well shown in Figs; 3 and 5, for

' driving purposes; a supporting frame designated generally by F, and well shown in Figs. 4 and 1,

The specific embodiment of for supporting a body, B, to be vbalanced while that body isibeing rotated by'the motor, M;

indicating means, I, well shown in Figs. 6 and '1, simultaneously operative for exhibiting the extent of oscillation of frame F about each of two axes when a body to be balanced is supported thereby andis rotated by the motor M.

applicant's invention shown in the drawings provides a suitable case, within which and withoutwhich various members going to make up the device are supported, so that the device is what might be called self-contained.

Within the case i' andformed, preferably integral with a wall thereof, as: the front wall, are

lugs, as 2 and 2, one of which, 2, is shown in Fig.

5. and both of whichmre-shown in 6. Each and beta components for each end: may

has a substantial right nut i8. The' lower end of the link I,

Fig. 1. viewed from the.

direction of the arrows 23, the shaft'2i is threaded a diagrammatic view'illustrating shown in Fig.

is designated 21, as

vbe balanced. The belt on the side of the motor remote from the connection of the motor supporting arms, 5, a I

bracket I2 is attached in any suitable and appropriate manner as by welding. This bracket angled extension it provided with an aperture ll. The aperture it receives a link i5 threaded throughout and provided with a flanged sleeve it on the upper portion thereof, as viewed in Fig. 5. Between the flange of the sleeve l5 and the extension i3 and surrounding the sleeve and bearing upon thc flange and the extension i3 is a compression spring l1. Below the extension ltis a threaded w as shown in Fig. 5, receives the end of a crank pin l9, which isalso well shown in Fig. 3. Crank pin H, as best shown in .Fig. 3, is part of the crank arm which is, mounted rigidly upon a shaft 2| extending through the side of the casing l and journaled in a bearing 22 formed, preferably, integral with the casing l. The outer end of the shaft 2|, that is, the right hand end as viewed in Fig. 3, is provided with an outstanding arm 23, shown in Fig. 3, and also shownin side elevation in Fig. 2.

24 at the extremity remote from the shaft 2| ture 25 in the end through which the shaft 2i is passed, correspondlngwith. a square portion of the shaft 2! adjacent-the end. Beyond the arm for the reception of a nut --28 which when screwed in place holds the handle member 23 firmly inplace on the shaft 2i.

By the construction just hereinbefore described the handle piece affordsa means by which a manualoperation may be performed to raise or lower the arm 23, as shown crank pin cred. When link I! is raised, the motor M, as

5, is raised, that is, when handle This arm has-a handle piece in Fig.- 2. thereby oscillating shaft 2i and with it the crank 20 and is whereby link i! is raised and low- I piece 24 is raised, the motor M is raised. When handle piece 24 is lowered, link I! is lowered and the flanged sleeve i8 is drawn downwardly with link I5 compressing spring l'l against extension ii of the member I! attached to themotor M and so resiliently pressing the motor M downwardly.

Motor M has an armature, the'shaft of which best shown in Fig. 5. This shaft extends through the side of the casing i, and, within a'pulley and beltguard 28 on the side ofthe casing i, bears a belt pulley 29, as

best shownin Fig. 3. This pulley 29 serves as a driving means for a.,belt 20, as shown in Fig. 3 and Fig. l, employed for driving the body B to 30, as best shown in Fig. 2, passes around. the pulley 2!, then under the body B and in contact therewith, then around a pulley 22 and back to pulley 29.

From the hereinbefore given description it will now be apparent that a body B to be balanced is in a position, as shown in Fig. 2, then if the handle piece 24 is lowered the pulley 29 will contact firmly with the belt 30 driving the same and" Fig. 2. Each of these rods is threaded on each 7 causing a rotative eflort upon the body B or if handle piece 24 is raised, as shown in Fig. 2, then the pulley 291 will not bear sufliclently tightly upon the belt to cause it to be driven and consequently the body B will not have a rotaend for receiving nuts as 35, 36, 31 and 38, as perhaps best shown in Fig. 4. Each rod has the inner raceway of a ball bearing belt pulley, guide or idler mounted thereon, as best shown in Fig. 2, in which the raceway on rbd 34 for idler 3| is designated 33 and the raceway on rod 33 for idler 32 is designated 40. As best shown in Fig. 4, a cross arm 4| is provided apertured on each end for the reception of the

rods

33 and 34. In order to position the cross arm 4| and hold it firmly in place and also position and hold firmly in place the inner races of the ball bearare exactly like those placed about 33, are two short pieces 42 and 43 between the inner race the nuts 36 and 38.

ings 39 and 4!), tubes are placed about the

rods

33 and 34. The tubes placed about rod 34-, which of the ball bearing member and 'two arms 44 and .45 which are aperturedfto receive the rod 34; another tube 46 between the arm 44 and the nut 35; and another tube4'l between the arm 45 and the end of the member 4|. When nuts 35 and 31 are screwed tightly in place on the ends of the rod 34, the arm 4|, the

arms

44 and 45; and the inner ball race '33 are all held firmly in place so 'as to be free from longitudinal movement upon the rod 34. By an identical construction the other end of the member 4| through which rod 33 passes and the inner ball race 40 and

arms

48 and 49 together with the tubes on the rod.33 I

are all held rigidly in place upon screwing on In order to support the body 3 to bebalanced, stretchers '50 and 5|, best shown in Fig.4, are provided. These stretchersextend from side to side of the frame resting upon the tubes surrounding the rods- 33 and 34 and are slidable longitudinal of the tubesS Each is provided with a half round bearing 52 as perhaps best shown in Fig. 2 for the reception of a shaft, as 53 of the body B to be balanced.

The frame F is supported by the

arms #

34, 45, 43 and 49. These arms as 48 and 43 are really the two legs of a U-shaped member provided with a slot, as 54, as best shown in Fig. 1. Through this slot 54 extends two'

leaf springs

55 and 56. Each spring is bent at a right angle so that a portion thereof, as 51 and 58, lies against the inside of the base of the U-shaped member. Above these turned over portions isa plate, as 59, pressed firmly against the turned over portions 51 and 58 and fastened rigidly in any suitable or appropriate manner as by welding to the

arms

48 and 49. The lower ends of the

spring members

55 and 56 extend down into a slot as 30- in the end of one arm of a two armed lever 6| as shown in Figs. 1 and 2. Two armed lever 3| is rigidly mounted upon the shaft 62 mounted in ball bearings -63 and 64 supported by the case As the frame F is supported at a point approximating its longitudinal center on the symmetri cally formed two armed lever 6|, the frame is free to oscillate in a vertical plane transverse to its length, that is, about the axis of the shaft 62,

greater or lesser oscillation of the plates '15 and of Fig. 4. The frameF is also by reason of being that is, in the direction of the mm as and u' mounted upon the

flat springs

55 and 56, free to in the direction of the arrows 31 and 68 of Fig. 3.-

It is, of course, understood that by the term "free ,to oscillate hereinbefore used is meant free to oscillate'against such restraint as is imposed.

If a body B to be balanced is supported by the stretchers as 50 and 5I and the belt 33 is adjusted under the body as shown and then the belt is caused to bedriven by the motor M the body B ,will rotate about the longitudinal axis. If the body B is statically unbalanced then an oscillation of the frame F will be caused in the direction or the

arrows

55 and 66. If the body is dynamlcally unbalanced then an oscillation of frame F will be caused in the direction of the.

arrows 31 and sat .If both static and dynainic unbalance are present in the body 3 then both oscillations will simultaneously take place.

The extent of oscillation caused by alpha unbalance is restrained by the fiat spring 69, well shown in Figs. 8 and 5.

Spring 83 is attached to shaft 62 in any suitable or appropriate manner as by cap screw 10. The ends of the spring 69 extend in two directions substantially at right angles to shaft 62, as best shown in Fig. 5, and the ends thereof lie adjacentadjusting screws II and 12. By suitably adjusting the screws 1| and 12, a desired tension may be placed upon the spring 53 so that an alpha unbalance in the body B will cause a shaft 62.

The extent of oscillation caused by beta unbalance is restrained by

fiat springs

13 and 14,

shown in cross-section in Fig. 3, and in. side ele vation in Fig. 5 and in end elevation in Fig. 1. The upper spring 13 is clamped between the 16 attachedrto arm 4| and the lower spring It bears upon the top of the right angled arm 71 attached, as by a 'cap screw 18, so as to rotate with and about the longitudinal center line or axis of the shaft 62. The outer ends of the springs as shown in Fig. 5 are held together by adjustable clamps as l9 and. These clamps can be approached nearer together or be separated farther apart thereby increasing or decreasing the reactive power of the springs 13 and I4.

If the frame F is caused to oscillate in the direction of the arrow 63, Fig. '3, that is, about an axis transverse to the longitudinal axis of the body B it is to a certain extent restrained by'the action of springs 13 and I4 as spring 14 will bear upon the right angled arm l1 when the frame F moves in the direction of the arrow 38.

In order to exhibit the amount of oscillation caused by the alpha unbalance. and the amountcaused by the beta unbalance there have been provided an arm 8| extending out from shaft 62 and oscillatable with that shaft and an arm 32 pivoted on a bracket 33" intermediate its length and having one end positioned underneath and in contact withrod 84. The rod 34 is provided with threads on its upper end and screws into a cavity in the arm 4| and is adjustable by the knurled finger piece 85 so that its lower end may be adjusted so as to lie exactly on the longitudinal center line of the shaft 62 when the belt 30is not being driven.

' To the free ends of each of the levers 82' and would be a rather diflicult matter 1 trical contact may be balance in the body B pointers 96 and the arm 94 ration of the contacts ."swingofthearmsasll 8| is attached a thread like member, as 86 and 81, respectively. Each of the thread like members, as 86 and 81, passes several times about a small shaft, as 88 and 89, respectively, best shownin Fig. '1, and the end of each is attached to tension springs, as 99 and 9I, respectively. The shafts 88 and 89 are each suitably mounted for oscillation, as by having their ends formed conical and resting in conical depressions in members such as 92 and 98. Each shaft, as 88 and 89, has arms, as 94 and 95, respectively, extending substantially at a is continued by a pointer, as 96 and 91, respectively, forming a visible indicator.

The construction last above described is such that an oscillation of shaft 62 causes an oscillation of arm 8I and a movement of thread 81 which being wound about shaft-89 causes that shaft to rotate and the arm 95 and pointer 91 carried thereby to be oscillated. In the same way a vertical oscillation of the left hand end of the frame F, as viewed in Fig. 3, causes the rod 84 to move downwardly and oscillate lever 92 which by reason of being connected with thread 86 causes an oscillation of shaft 88 and the arm 94 and the pointer 96 connected therewith. The

pointers

96 and 91 may be viewed through an aperture in the front of the casingas shown in Fig. 1 and by the extent of their movement so may the value of alpha and beta unto be balanced, be determined.

As the

pointers

96 and 91 will be in a continual state of oscillation when the device is in use for ascertaining the unbalance of a body, it to determine alone the extreme swing 91. To the end of faciliaccurately by the eye. of the-pointers 96 and

tating determining pointers

96 and 91, applicant has provided pivoted sectors, as 98 and 99, adjacent each of the pointers, as 96 and 91, and has graduated the edges of these sectors 98 and- 99 adjacent the. 91, as indicated by Fig. 1 by I99 and Illl. On each of the sectors cooperating electrical contacts as I92 and W9 have been mounted. When a body 3 to be balanced is in motion and is causing an oscillation of arm 99 or arm 96 or both, a button I94 attached to sector 98 is grasped by the fingers and moved so as to bring the end of contact M2 closer and closer to arm 94 until a point is reached where contacting with I92 causes a sepa- I92 and 898. This marks the extreme oscillation of the arm 94 and pointer 91. In the same way the button I is moved until the arm 95 just breaks the electric contact associated therewith. 'The breaking of an'elecv indicated, ,as shownin Fig. 8, wherein a small lamp I96 is shown connected in circuit with the contacts I92 and I-89 and a source of-potential I81. when the proper adjustment of a sector as 98 is made the lamp will be extinguished upon each oscillation of the pointer or arm 94 in the direction towards the contact I92. This contact member I82, of course, must be made of such size that it'will not materially interfere with the free swing of the arm 94, that is, it must be extremely sensitive so asto require but very little appreciable force to operate it.-

After the exact adjustments of the sectors as 98 and 98 are obtained to indicate the extreme and 88 then after the from driving belt 89 by motorMhasbeenfi-eed right angle thereto and each arm the extreme swing of the.

masses causing centrifugal a manipulation of the hand piece 24 the sectors as 98 and 99 will be in such position that the extreme swing of the pointers as 99 and 91 which occurred is indicated by the amount of displacement of the sectors as 98 and 99 from an arbitrary zero position.

Applicant contemplates using a motor M of constant speed. He also contemplates so positioning the body B to be balanced that correction planes I98 and I99 will be positioned one on one side of the median line I I0 and the other on the other side thereof and each at the same distance from the median line and this median and provided with means for altering the mag nitude of the static and beta unbalance may be mounted upon the stretchers 69 and BI and then caused to rotate by depressing the handle piece 84. Readings may then be taken of the displacement of the

sectors

98 and 99 for a wide range of known changes in the magnitude of alpha and beta unbalance in me body of known characteristics and fromthese/readings the device may be calibrated so that upon placing a body asB in the device and rotating it and observing the necessary displacement of

sectors

98 and 99 the numerical magnitude of both alpha and beta unbalance in the body B may be ascertained. By a single mounting of the body or of the arrow's'61 and 88' further contemplates, in a determined as the body or rotor simultaneously oscillates 'with two degrees of freedom about two axes.

The mathematical relations which have to be observed when applying corrections determined by the use of the machine and the general mathematical relations which subsist and which exemplify the principles underlying the invention are illustrated by the diagrams Figs. 9 and 10. Fig. 9 illustrates the general case. Fig. 10 illustrates the special rangement of the specific embodiment shown in the drawings.

In Fig. 9, 3' indicates the unbalanced body; DA designates the beta axis; LA designates the longitudinalaxis, and may also be considered to represent the alpha axis. If the body B and numerical results determinative of both alpha and beta unbalance obtained, then after correction the correction masses will bear proper relation to one another as centrifugal forces. The correction mass CF! considered as a centrifugal force added to thecorrection mass CF: considered as a centrifugal force will equal the original unbalanced alpha centrifugal force, that is,

The moments ,generated by these centrifugal forces about the beta axis will bear the following relation: CF1sX=CF:xY. The above equations illustrate the disposition and relation of the forces which counterced alpha centrifugal force balance the unb is oscillatedair-1,00; a

but do not themselves'create an unbalanced beta force. t I e The masses determined by oscillation applied to body B to compensate beta unbalance are CF; and m. These masses considered as centrifugal forces have a relation which may be expressed by a formula as follows: CF3Xa+CF4Xb=original beta couple unbalance. These masses considered as centrifugal forces also bear the following relation: CFa-,= CF4. The foregoing equations and mathematical relations not only illustrate how correction masses are to be applied but also illustrate the fundamental relations which must subsist, as hereinbefore pointed out, in order that a correction mass ance without generating a beta unbalance and how a beta unbalance correction may be applied without generating an'alpha unbalance.

In- Fig. 10 the subsist withthe preferred special formof the invention as illustrated by the drawings is em ployed. When this special form is usedthe beta axis DA is positioned midway between the correction planes CP and CP', that is, :c=y=,a=b and R=R'.- Under'such conditions calculations and corrections may be made on the basis of weight rather than centrifugal force; W1=Wz and Wa=W4. a

In the particular arrangement shown in the drawings the magnitude or mass change necessary to correct the body B for alpha unbalance would be halved and one half assigned to each correction plane as I08 and I09. The magnitude or mass change necessary to correct for beta unbalance would also be halved and one half placed in the correction plane I08 and the other half placed in the correction plane I09. When making correction for alpha unbalance all of the mass changes would be made on one side of the longitudinal center line and in a line parallel thereto. When making correction for beta unbalance one portion any mass change may be made to correct are two masses in each correction would be placed on one side-oi the longitudinal center line and the other portion on the other side of the longitudinal center line'and on the other side of the transverse axis upon which oscillation takes place to determine the extent of beta unbalance and correction mass in'one plane would be angularly 180 degrees from the position of the correction mass in the other plane, that is, if the beta correction mass were placed in the correction plane I8, in the plane right hand corner of body B as shown in Fig. 10, then the other correction mass for beta unbalance would be placed, in the plane of the paper, in correction plane I09 at the lower left hand corner of the body B as viewed in Fig. 10.

Applicants device does not determine what is technically known as high point" or angle of lag. It merely determines the numerical magnitudes necessary to correct for unbalance. Before for unbalance the high point and angle of lag determined. This may be done by well known and approved methods thoroughly understood by termined the numerical magnitudes ascertained by applicant's device are then distributed in the two correction planes in accordance with the determined high point and angle of lag. As there plane, one for alpha and the other for beta unbalance, it is perfectly feasible before actually applying any correction mass by computation as vectorially, to ascertain a single resultant correction mass for may be applied for alpha unbal-' mathematical relations which of the paper at the upper must be with this resultant in each plane.

By applicants device a single positioning of a body to be balanced is made and after thatpositioning a rotation thereof is caused from which data is secured sumcient to ascertain in connection with the high point ahd angle of lag the necessary mass changes in on thereof in order to balance the body both statically and dynamically and the instrument readings by which. the magnitude is ascertained persist so that they may be read at leisure, as the rotative displacement of are stationary at the time of reading. In order to actually balance a body which is in unbalance it is necessary to determine the high spot, angle of lag, and magnitude of the unbalance.

In order to determine'the high spot, the body is mounted in the frame F just as the body B is mounted. While the body is moving freely about both the alpha and the beta axes, a scribe is placed I confusion with the caused tolightly mark will be made beta unbalance.

alpha high spot and the scribe touch the shaft whereupon a indicative of the high point for In order to determine the angle of lag, it is to be remembered that the body is mounted resiliently, that is with a minimum damping, consequently, the angle of the high spot behind the age of change in speed either above or below the critical or resonant speed. The resonance mentioned above is readily detected by the extreme or maximum vibration which is evidenced when the body is rotated. This may be and usually is observed by the unaided eye. The speed is generally increased until it is greater than the resonant speed and thenthe driving power is shut off and the body allowed to coast to a stop. The going of the body through the critical or resonant speed is tude of vibration.

The magnitude of unbalance is obtained by measuring the linear displacement 'of the rotating two bodies, both of which the body and the posireadily observable by the amplition may be accomplished mathematically from static measurement of the mass of the system and elasticity of the springs or more practically by placing a body in the machine, making high spot and alpha and beta unbalance reading and then known test weights being applied at known points and the reduction in vibration produced by the known weights noted. Since the restraining springs have a, straight line elastic characteristic the calibration curve is a straight line and there fore only two points are necessary to draw the curve.

If a body such as that shown by Fig. is to be balanced and the correction planes are the planes of the ends of the body, the body would be placed in the machine as shown by Figs. 1 to 8 inclusive and rotated and the alpha reading and the beta reading are both 10 cated by the

pointers

96 and 91. The readings are taken above resonance therefore the lag angle is 180 degrees and the highspots are the light spots, the angular location of the high spots would be determined by a scriber as hereinbefore pointed out, the alpha high spot by a scrlber in a horizontal plane and the beta high spot by the scriber in a vertical plane. Since the body was placed in the machine with the beta axis midway between the end planes of the body all of the data is now obtained by which-to balance the body.

In Figs. 11 and ends of the body as shown by Fig. 10 but both ends are viewed from the same end. lnlFig. 11, iii designates the correction weight of five units applied to the left hand of the body shown in Fig. ll), at the alpha high spot, or light spot. In Fig. 12, H3 designates a correction weight of five units applied to the right hand end of the body shown by Fig. 10 at the alpha high spot or light spot.

In Fig. 11, ill designates a beta correction weight the left hand end of .the

of five units applied to body as shown by Fig. or light spot.

The other weight of the beta couple is applied 180 degrees from the weight I It at the other end or right hand end of the body ill and is desi nated M5.

10 at the beta high spot It will be noted that the alpha correctionweights have been so located with respect to the beta axes that the couple created by these weights about the beta axis iszero,therefore the beta component of unbalance in the body has not been disturbed by applying the correction of alpha unbalance. In the same way, the correction for beta-unbalance has been divided between thecorrection planes to produce a balancing couple without introducing any change in the unbalance of the body as respects the alpha axis. Since the body has been balanced for both alpha and beta components and is suspended with two degrees of freedom, it will be in balance when rotated in any type of suspension.

Although I have particularly described the principle of operation nevertheless, I desire to have it understood that the particular physical embodiment selected is merely illustrative and does not exhaust the pus--v sible physical embodiments of the idea of means underlying my invention or the physical embodiments by which my invention may be practiced.-

This application is a division of my copending units on the scaleas indi 12 are shown two views of the and construction of a particular physical embodiment of my invention,"

shaft mounted for oscillation;

. awaees application Serial No. 431,719,- filed February 2'7,

1. In a balancing machine, in combination: a

shaft mounted foroscillation; resilient means restraining oscillation of the shaft; a frame supported by the shaft; resilient means between the frame and the shaft allowing oscillation of the frame about an axis at a right angle to the axis of the shaft; a third resilient means uniforml restraining the last mentioned oscillation of the frame in any oscillated positionof the shaft; a member attached to the frame and terminating at the longitudinal center line of the shaft prolonged when the frame is at rest in uno'scilla'ted position; means actuated by said last named member for indicating the extent of oscillation of the frame; a member attached to the shaft;

- means actuated by said last named member for indicating the extent of oscillation of the shaft; and means for supporting on the frame a body to be balanced and rotating it whereby oscillations of the shaft and the frame will be caused and the extent of such oscillations are usable in calculating the masschanges necessary to balance the body.

2. In an indicator for a balancing machine, in combination: a. first pivoted pointer; a second pivoted pointer; means for pivoting each pointer in-one direction by oscillations caused by the rotation of an unbalanced rotating body; means for returning each pointer to initial positions; a pivoted sector adjacent each pointer, shiftable over substantially the arc of movement of the adjacent pointer; a set of cooperating electrical contacts on each sector, each set having an arm lying in the path of movement of a pointer when a sector is properly adjusted; electrical circuits for each set including an electrically energizable device and a source of energy whereby when the polinters are oscillated and the. sectors are proper y erated toinfluence the electrically energizable lation of the pointers is ascertained.

3. In a balancing machine, in combination: means for rotating a body to be.balanced; a frame for supporting thebody to be balanced whileit is rotating; means allowing the frame to oscillate restrainedly simultaneously on two axes one at a right angle to the other, one axis being between and at known distances from at least two correction planes of the body; means simultaneously acting for indicating the extent of movement on each axis whereby data usable in correcting the body for unbalance is obtained.-

4. In a balancing machine, in combination: a shaft mounted for restrained oscillation; a frame supported by the shaft; means for supporting a body to be balanced for rotation on the frame; means for driving the body; means allowing the frame to oscillate restrainedly with the oscillation of the shaft on an axis at aright angle to the axis of the shaft, said last mentioned axis positioned between and at known distances from at least two correction planes of the body; means for simultaneously determining the extent of oscillation of the shaft and the oscillation of the frame at a right angle to the axis thereof when the body is rotated whereby data usable in correcting the body for unbalance is obtained.

5. In a balancing machine, in combination: a

adjusted the cooperating contacts are op-' simultaneously I I a frame supported by the shaft; means for supporting and rotating a body to be balanced on the frame; means connecting the shaft and the frame whereby the frame may oscillate about an axis at a right angle to the axis to the shaft, said last mentioned" axis being between and at known distances from at least two correction planes of the body; resilient means for restraining the said oscillation of the frame; means attached to the shaft and oscillatable therewith for bearing against the said resilient means whereby the said resilient means is tensioned uniformly for all positions of the said shaft.

6. In a balancing machine, in combination: a motor; means for rotating a body to be balanced driven by the motor; a frame for supporting the body to be balanced while it is rotating; means allowing the frame to oscillate restrainedly simultaneously on two axes one at a right angle to the other, one of said axes being between and at known distances from at least two correction planes of the body; means simultaneously acting for indicating the extent of movement on each axis whereby data usable in correcting the body for unbalance is obtained.

7 -7. In a balancing machine, in combination: a housing; orificed lugs attached to the housing;

. pins, one passing through an orifice of each lug;

supporting arms, each supporting arm formed with an orifice at one end and a plurality of spaced orificed lugs at the other end, each supporting arm being pivoted on one of the said pins; a motor provided with lugs matching the lugs of the arms and orifices for fastening thereto by screw-like'means and screw-like means for such attachment; a bracket attached to the motor; a link resiliently attached to the bracket; a crank connected to the link; and means for operating the crank whereby the motor is oscillated; a belt pulley driven by the motor; a belt driven by the belt pulley; a frame having two degrees of free-- dom and provided with means for supporting a body to be balanced; and means for-guiding the belt in contact with the body to be balanced whereby the body to be balanced is rotated.

'8. In a balancingmachine, in combination:

; means for rotating a body to be balanced; a frame for supporting the body to be balanced while it is rotating; means allowing the'frame to oscillate restrainedly simultaneously on two axes one at a right angle to the other, and one axis between and at known distances from at least twocorrect ion planes ,of the body; means simulta- 4 neously acting for indicating the extent of movement on eachaxis whereby data usable in correcting the body for unbalance is obtained.

9. In a balancing machine, in combination: means for rotating a body to be balanced; a frame for supporting the body to be balanced while it is rotating; means-allowing the frame to oscillate restrainedly simultaneously on two axes, one at a right angle to the other. one of said axes being between two arbitrary planes of the body within which correction for unbalance is to bemade and at known distancestherefrom; and means simultaneously acting for indicating the extent of movement on each axis whereby data usable in correcting the body for unbalance is'obtained.

10. In a balancing machine, in combination: means for rotating a body to be balanced; a frame for supporting the body to be balanced while it is rotated; means allowing the frame to oscillate restrainedly simultaneously on two axes, one at a right angle to the other, one axis being between and at known distances from at least two correction planes of the body; means manually controllable for indicating the extent of movement on each axis whereby data useable in correcting the body'for unbalance is obtained.

STANLEY n. LIVINGSTON.