US2123443A - Balancing machine - Google Patents

Description

July 12, 1938. J. L. TAYLOR 2,123,443

BALANCINGMACHINE Filed Nov. s, 1955 e'sheets-sneet 1 Filed Nov. s; 1935 9 Shgets-Sheet 2 July 12, 1938. v J.'L.-TAYLCIJR 32,123,443

BALANCINGT MACHINE Filed Nov. 3, 1935' 9 Sheets-Sheet s ll lll- INVENTOR.

July 12, 1938. 1L. TAYLOR 2,123,443

' BALANCING MACHINE Filed ov; :5, 1935 9 Sheets-Sheet 4 INVENTOR.

July 12, 1938. J. TAYLOR I ,443

BALANCINGT MACHINE I Filed Nov. s, 1935 9 sheets-sheets NVENTOR.

J. L. TAYLOR B1.LAIICINC1. MACHINE Filed Nov. 3, 1933 July 12, 1938.

9 Sheets-Sheet 6 IQeP.

FIG. 2.4.

Jufly l2, 1%.. J. L..TAYLOR 2,123,443 I V BALANCING MACHINE Filed Nbv. a, 1925 9 Sheets-Sheet 7 VENTOR.

July 12:, 1938. x J. 1.. TAYLOR BALANCING: MACHINE Filed Nov.' 3, 1

9 Sheds-Sheet a IIIIIIIIIIIIMII July 12, 1938 J. L. TAYLOR BALANCING: MACHINE Filed Nov. a, 1955 9 Sheets-Sheet 9 W I g z Patented July -12, 1938 PATENT OFFICE BALANCING MACHINE John Leonard Taylor, Milwaukee, Wis.; Grace Brindley Taylor, executrix of said John Leonard Taylor, deceased Application November 3, 1933, Serial No. 696,559

13 Claims.

The present invention relates to balancing mechanism for rotative bodies, and an object of the invention is to generally improve the construction and operation of such mechanism.

A further object is to provide novel mechanism for balancing rotative bodies.

Further objects are to provide the following:

Mechanism for performing dynamic balancing including a bearing arranged to support a work piece substantially rigidly, but to permit slight deformation or deflection under centrifugal forces developed by rotation of unbalanced weight in a an electric circuit, and indicating means coni nected with said circuit and responsive to said circuit controlling means;

Such a machine having a plurality of such bearings spaced at desired points in the length of a work piece, and indicating means responsive to the circuit controlling means in said bearings;

Indicating meansfor indicating the position of a work piece when movement of the movable portion of one of said bearings takesplace, including a rotative member operating synchronously with said work piece, and means for illuminating said member periodically in accordance with movements of said movable portion;

Such indicating means including a dial rotating synchronously with the work piece and an index arranged to be fixed relatively to the dial at the instant deflection takes place in the work piece;

Mechanism for automatically compensating for lag occurring in the above outlined indicating means;

The combination of mechanism as outlined above with mechanism for correcting the unbalance of a work piece without removing it from the testing apparatus;

Mechanism for performing certain calculations requiredin determining the amount of unbalance in a work piece.

A a face-plate construction indicated in Fig. 1.

these objects are illustrated in the annexed drawings in which:

Fig. 1 is a front elevation of an illustrative machine arranged for the practice of the invention, parts being broken away for a better showing of 5 certain other parts.

Fig. 2 is an enlarged sectional elevation of the same machine taken on the line 2-2 of Fig. 1, parts being broken away.

Fig. 3 is a horizontal sectional View taken sub- 1 stahtially on the line 3-3 of Fig. 1 and enlarged.

Fig. 4-is an enlarged detail of certain mechanism indicated in Fig.1.

Fig.5 is an enlarged detail partly in section of I 15 Fig. dis a vertical sectional view taken onthe 'line 6--6 of Figs. 1 and 3, with certain parts in full. i

Fig. 'Zis an enlargedsectional detail of mechanism indicated in Fig. 2, taken on theline 'l--'I of Fig. 2.

Fig. 8 is a vertical sectional view of the same .taken on the line 8-8 of Fig. '7.

Fig. 9 is a sectional view on the line 99 of Fig. 8.

Fig. 10 is a sectional view on the line Iii-40 of Fig. 8.

Fig. 11 is a sectional view on the line i |-l l of Fig. 8.

Fig. 12 is an enlarged front elevation of a bearing element indicated in Fig. 1.

Fig. 13 is an enlarged vertical axial sectional view of mechanism indicated in Fig.

Fig. 13a is a sectional view taken on the line l3a-l3a of Fig. 13.

Fig. 14 is a plan View of a portion of the structure shown in Fig-13.

Fig. 15 is a sectional view taken on the line l5l5 'of Fig. 13.

Fig. 16 is an enlarged detail of a portion of Fig. 13 showing a different adjustment of the parts. I

Fig. 17 is an enlarged detail of a pivot construction shown in Fig. 13.

Fig. 18 is an enlarged front elevation of an 5 indicator shown in Fig.1, parts being broken away.

Fig. 19 is a vertical sectional view of the same.

Fig. 20 is a diagram of the electrical connec tions used with this indicator.

Fig. 21 is an enlarged front elevation of a different type of indicator which may be used with the machine, parts being broken away to show' the interior.

Fig.'22 is a vertical sectional view of the same. 55

Fig. 23 is a sectional view on the line 2323 of Fig. 21.

Fig. 24 is a diagram of the electrical connections used with this indicator.

Fig. 25 is a vertical axial sectional view of another type of indicator which may be used with the machine.

Fig. 26 is an exploded view of certain parts indicated in Fig. 25.

Fig. 27 is a front elevation of the structure shown in Fig. 25.

Fig. 28 is a diagram of the electrical connections used with this type of indicator.

Fig. 29 is a vertical sectional view of the machine taken on the line 29-28 of Fig. 1.

Fig. 29a is a vertical elevation showing detail arrangement of dial indicator.

Fig. 30 is a vertical sectional view of a modified form of indicating means for the machine.

Fig. 31 is a front elevation of the same in partial section along the line 3l-3I of Fig. 30.

Fig. 32 is a front elevation of the dial portion of the device with parts broken away to show the underlying construction.

Fig. 33 is a detail showing a modification of certain mechanismindicated in Fig. 30.

, Similar reference characters have been applied to the same parts throughout the drawings and the following specification.

It is well known that rotative parts, particularly such as are characterized by considerable length, unless accurately balanced substantially continuously throughout such length, are subiect to distortion under the centrifugal effects of unbalanced weight when rotated at high speed. Such a piece may be perfectly statically balanced, and perfectly dynamically balanced in the ordinary manner, and still contain unbalanced weight such as will produce such stresses and distortion when the piece is placed in service.

The present invention operates by rotating the piece under conditions approximating those under which it operates in service, and determining, from the distortions which take place, the locations and magnitudes of the unbalanced weights in the piece, whereupon they can be eliminated and the tendency toward distortion destroyed.

In balancing with the disclosed apparatus the work piece is supported at a plurality of axially spaced points and maintained substantially positively in alignment at each of said points while it is rotated at a speed preferably in the neighborhood of that at which it will be run in service, although any speed high enough to develop substantial centrifugal forces in the piece would serve the purpose, and there is no objection to speeds higher than the service speeds so long as they are within the capacity of the apparatus used. The piece is not allowed to vibrate substantially as a whole, contrary to the usual practice in dynamic balancing, but is held in alignment by substantial pressure at each of the spaced points, and while the piece is rotating the pressure is reduced at these points, one at a time, so that the piece may distort at each point. The position of the piece at which distortion takes place is observed by any suitable mechanism, and the pressure necessary at each point to prevent the distortion is noted. From these data in conjunction with the known speed of rotatioh of the work piece the value of the unbalanced weights or heavy spots in the piece may be readily calculated, as well as the amount of material to be removed at each determined location in order to put the piece in what might be termed continuous dynamic balance.

If the piece has been previously balanced by supporting it at its ends, assuming it to be rigid, and correcting it until there is no tendency to displacement of the ends, the piece may be said in one sense to be dynamically balanced, but the piece is not rigid, and there will still exist heavy spots which are axially spaced from each other, but so located angularly that they balance each other statically or dynamically when the piece is tested as above at moderate speeds. At high speeds, however, they do not balance each other since because of their axial displacement, they cause a distortion or "whip of the shaft which renders further testing by the outlined method impossible. The piece is accordingly not balanced, and when so distorted will cause serious vibration and wear on its bearings, and other well known undesirable results. By utilizing such distortions to locate these axially spaced heavy spots, they can be discovered and eliminated, whereupon the piece will be in a true state of dynamic balance, and will have superior operating characteristics heretofore unknown.

As seen in the drawings the present mechanism includes a bed or base generically designated by numeral I, Figs. 1 and 2, carrying a tail-stock 2, and a head-stock 3, the part to be tested, in the present instance indicated as a crank-shaft 4, being supported from base I between head-stock 3 and tail-stock 2 in a plurality of bearing units generically designated by numeral 5. Each of the bearing elements supports in the present instance one of the journals of the shaft 4 through a plurality of rolls 6, I, and 8, rolls 6 and I being substantially rigidly fixed in position, and roll 8 being capable of movement radially of the shaft journal 9. This move-.

ment of roll 8 is suitably resisted, and actuates, through intervening mechanism described below, an electrical contacting mechanism generically designated by numeral ill, the resulting impulses affecting an indicating device generically designated by numeral II, which serves to indicate the angular position of the shaft or work piece at the instant that distortion of the piece causing movement of roll 8 takes place. The amount of. resistance opposed to movement of roll 8 may be regulated by means of a cap, grip, or the like i2 which may be provided with graduations for directly indicating the force exerted. Rotation may be imparted to the work piece through head-stock 3 from a motor l3, and current may be supplied for the operation of indicator H by means of a generator ll also driven from motor l3. The speed of rotation of the work piece is indicated at a suitable tachometer or other speed indicating device l5.

The specific details of the mechanism may be varied to a considerable extent, but for purposes of illustration a complete operative structure has been disclosed which will be completely described. It is to be understood, however, that nothing in the specific embodiment shown and described is intended to limit the protection solicited, and that the invention is not limited in any'manner except as defined by the subjoined claims.

As illustrated in Figs. 1 and 2, base I comprises a boxlike structure suitably ribbed for stiffness and stability, and provided with openings l8 for access'to the interior thereof, and having a bracket H for supporting motor I! and generator 35 the like 3636.

l4. The base is provided with guideportions l8 and I9 running lengthwise thereof, and ribs or shelf portions 20 and 2| extend forwardly and rearwardly respectively immediately below the 5 guides. The guides are for the purpose of guiding tail-stock 2 and bearings 5 to various positions on the base to accommodate work pieces of diiferent sizes, the guides in the present in;- stance being of dove-tail cross section as shown in Fig. 2 to interlock with suitable portions of the other elements.

The clamping. means used on the tail-stock is identical with that used on the several bearing elements 5, so a description of the bearing 15 clamps will suflicefor all. As seen in Fig; 2,

the bearing elements have downwardly projecting portions or feet 22 and 23, having downwardly extending members 24 and 25 respectively, these members being provided with angu- 20 lar guiding surfaces 26 and 21 cooperating with complementary surfaces on guides l8 and I9.

.jIhe surfaces are maintained in their correct relation by clamping elements 28 and 29 urged into position by bolts or the like 30 and 3| against angular surfaces 32 and 33 respectively on guides I8 and IS, the clamps also engaging surfaces 34 and 35o'n portions 22 and 23 so as to urge the bearing member 5 firmly down on the guides l8 and I!) when bolts 38 and 3| are tightened.

A similar arrangement may be used if desired to fasten head-stock 3 down on the base, but, since it is not necessary to change the position of the head-stock, it may if desired be bolted permanently to the The machine is'preferably arranged for the accommodation of a variety of sizes and types of work pieces, the tail-stock2 being movable,

and the bearing members 5 being movable, and 40 removable; so that as many bearings may be used-as there are journals on the work piece,

the remaining bearings being removed and stored.

The particular form of guides l8 and i9 facilitates removal and replacement of the bearing 45 members, since, when the clamps 28 and 29 are loosened, the bearing members can be lifted directly off the base I with only a slight backward movement necessitated by the slope of the surfaces 26 and 21. In the testing of cylin- 50 drical or other objects, having no well defined journals as many bearings as prove to be necessary or desirable may be applied at various points along the length of the piece. Examples of such wvork pieces would include drive shafts, calendar 55 rolls, and certain types of rotors for. electrical machinery.

Provision is made for convenience in setting up a work piece to be tested. Movable rolls 8 are carried through intermediate elements de- 60 scribed below by brackets 31 which may swing about suitable pivots to permit the work piece to be placed in position as in a lathe between centers 38, on tail- stock 2, and 39, (Fig. 3) on head-stock 3. Rolls 6, 1, and 8 are then ad- .65 vanced into contacting relation to the work piece 70 if desired as above outlined after which the rolls 8 are withdrawn and the piece lifted out of the machine. Asimilar piece may then be placed in the machine, and rolls 8 engaged with it without the necessity for going through the center- 75 ing process again.

base by means of bolts or- It is to be noted that the supporting means carrying rolls 1 are disposed slightly forwardly of a vertical radius of journal 9. The work pieceis therefore stably supported in the machine even when rolls 8 are withdrawn, since the tendency is for it to move rearwardly against rolls 6. This feature facilitates the removal of material from the piece as described below, since the rolls 6 and 1 are'rigidly supported, and the support of the work-piece against. the cutting reactions is furnished by these. rolls, and not by the yielding rolls 8, the piece being rigidly supported on rolls 6 and 1 without dependence on roll 8.

Tail-stock 2 may be of any suitable or desired type, but in the present instance it has a body portion 40 provided with a screw actuated or other suitable ram or plunger 4| carrying abovementioned center 38, the body being provided with suitable means such as a lever 42 for clamping the plunger in desired positions.

Center 38 is provided with a small flat surface at its tip as shown in Fig. 4, and after the work piece is suitably supported in bearings 5, the

' ing plunger 4| is operated from a hand wheel or the like 44.

' Head-stock 3 as particularly shown in Figs. 1 and 3 includes a housing or body portion 45 within which is suitably journaled a spindle generically designated by numeral 46, and in the present instance formedin two telescoping sections 41, and 48, the spindle being 'driven' from motor l3 by means of a belt 49, in the present instance of V-type, operating on a cone pulley 58; on motor l3, and driving the spindle by'means of a cone pulley 5!. By placing the belt on'one or another of the various sized sheaves comprising the cones, various speeds may be obtained. in

the spindle 46, and motor l3 may be of a variable speed type if desired to obtain still other variations of the speed in the spindle although ordinarily the variation provided in the pulleys should be sufficient.

To provide for promptlystopping the'rotation of the parts when desired pulley 5| serves also the purpose of a brakedrum, having an internal braking surface or bore 52 with which cooperates a brake shoe of suitable type 53 provided with friction material 54 and anchored on a stud or the like 55 fixedwith casing 45. The shoe may be expanded by operation of a handlever or the like 56 extending forwardly into a convenient position, and actuating through a shaft 51 journaled in a bearing 58 on housing 45 a cam 59 acting on the shoe in any suitable or well known manner when the shaft is turned by actuation of the lever 56.

Shaft portion 4'! is suitably journaled at one end in a bearing 60 fixed with housing 45, and at its other end it is supported in the bore. of porwith bearing 61 while the driving connectionbetween the shaft portions is maintained. Portion 48 is prevented from moving axially in one direction in bearing portion 6| by a collar 63,

tion 48 which is in the form of a sleeve jour-. v

and in the other direction by a flange 64. Flange 64 also provides an abutment for a face plate 65 which may be threaded on the shaft portion in the manner common in machines of this type, the face plate being provided with a borefor the reception of center 39 and with means for driving the work piece.

In the present instance the face plate is provided with a plurality of pins 66--66, spaced to enter bolt holes or the like customarily found in work pieces bf the typedisclosed, the pins being fixed in the face plate as more particularly shown in Fig. 5, and provided with sleeves or bushings of yieldable material such for example as rubber 61-61. The bushings permit slight misalignment of the face plate and work piece without causing any binding of the working parts such as would affect the accuracy of the readings. To prevent axial movement of the work piece toward the face plate bushings 61 are provided with fianges or the like 68, the piece when being tested being supported in the several bearings and floating between ball 43 and flanges 68.

Other types of drive are contemplated, and will be required for different work pieces, but their form and character will depend upon the individual types of work piece upon which the machine is to operate. When a work piece is tested requiring a different form of drive from that shown, the face plate 65 may be unscrewed and another fitting of suitable type substituted.

For axially moving portion bearing 6| is provided with a rack portion 69 traveling in the present instance in a slot 18 in guide 62, the rack being actuated by a sector 1| pivoted on a pin 12 or the like carried by a portion 19 of guide 62, the sector having a lever 14 fixed therewith and extended to a point within convenient reach of an operator. Swinging of the lever from side to side accordingly causes in and out movement of bearings 6| and spindle portion 48 together with its attached face plate 65 or other fitting. A spring 15 disposed between lever 14 and an anchorage 16 on head stock 45 serves to urge the lever yieldingly to the right as seen in Fig. 3, and prevent undesired retraction of spindle portion 48. The retracting feature of spindle portion 48 is useful in that it permits the ready removal of the center 39 after the work piece is set up in bearings 5, and subsequently it permits the entering and withdrawal of pins 66 as new pieces are placed in the machine for testing.

Spindle portion 41 has a spiral or other suitable gear 11 fixed therewith which drives a gear 18 fixed on a shaft 19 extending, diagonally upward to drive the indicating device II as more particularly shown in Fig. 6. A gear 88 engages gear 11 below shaft 41, the gear being fixed on a shaft 8| journaled in a bearing 82 suitably supported in housing 45, the shaft being prevented from moving axially by engagement of gear 88 and a collar 83 with the ends of bearing 82. A coupling element 84 of any suitable type conn cts shaft 8| with the operative element of a flexible shaft 85 of suitable or well known type of which the outside casing only is shown, the shaft extending to above mentioned tachometer I in familiar manner. This type of drive permits convenient location of the instrument without the necessity for alignment of driving shafts, and permits also removal of the instrument if desired for access to other parts of the apparatus, A removable bottom plate 86 permits access to the interior of housing 45 for assembly or inspection.

Continuing with the purely mechanical phases of the apparatus, each of bearings 5, includes a frame or body portion 81, Fig. 2, which as above described is fixed with guides I8 and I9 by suitable clamping means above described, the frame acting'to support the various elements carrying rolls 6, 1, and 8. Rolls 6 and 1 are journaled on pins or the like 88, each fixed in a bifurcated member 89 more particularly shown in Figs. 7 to 11 inclusive, the member comprising a fiat bar slotted for most of its length so as to provide lengthwise portions or legs 98 and 9| connected by a web 92, as clearly shown in Figs. 8 and 9, web 92 having forwardly projecting ears 93 and .94 carrying above mentioned pin 88, the pin being retained in aligned bores in the cars by a pin 95 or the like, as shown in Fig. 7. Member 89 is slidable in a hub or clamp portion 96 fixed with frame portion 81 and may be clamped therein to preserve a fixed relation to a work piece. To provide for ready and accurate longitudinal adjustment of member 89, a screw 91 is provided extending lengthwise between members 98 and 9I, the screw having a collar 98 fixed therewith as for example by means of a pin 99 engaging opposed transverse slots in the members, whereby longitudinal movement of the screw will cause similar movement of the member 89. The screw engages within the hub 96 in the present instance a pair of half-nuts I88 and I8I of a cross section of a part of a circle and constituted to fit within a cylindrical bore I82 in hub 96 and against the sides of member 89, the half-nuts having inwardly extending threaded portions I83 and I84 extending into the space between members 98 and 9| and Into engagement with the threads of screw 91. Half-nuts I88 and I8I are retained in the bore I82 by means of set screws or the like I85 and I86, threaded into the sides of hub 96 and entering suitable bores in the halfnuts. Rotation of the screw will accordingly cause longitudinal movement of member 89. Screw 91 maybe rotated by means of a knob, grip, or the like I81, and a lock nut I88 may be provided engageable with the ends of members 98 and 9| to maintain any desired adjustment of the screw.

Hub portion 96 is slotted at I89, and provided with upstanding ears H8 and II I through which extends a bolt or the like I I2. The bolt in the present instance is threaded in ear I I I, and may be rotated by a lever II3'fixed therewith by suitable means such as a pin II4, tightening of the bolt compressing the hub 96 and clamping the half-nuts and members 98 and 9| securely together within the hub.

A duplicate of member 89 and its associated parts is located in an upwardly extending position in the lower middle portion of frame 81 for supporting roll 1 for carrying the weight of the part of the work piece concerning the particular bearing element, and it is received in a boss or hub portion I I5, Fig. 2 depending from the frame and slotted at II6 to permit compressing by a bolt I I2 for clamping the member 89 in the manner outlined above.

As shown in Fig. 2, boss II5 supports member 89 carrying roll 1 in a position slightly inclined rearwardly toward the axis of the work piece, whereby the work piece is stably supported on rolls 1 and 6 even when rolls 8 are removed from contact with it. As a result of this disposition of rolls 6 and 1, a downward thrust, as from a cutter, will have no component in the direction of roll 8, and the yielding characteristic of this roll will accordingly have no undesirable efi'ect on the support of the work piece for cutting.

The movements measured in the machine are very small, and it isaccordingly important to preserve insofar as possible perfectly round faces on the rolls 6 and 1. To prevent damage of the rollsor the work pieces from impacts arising as the pieces are being placed in the machine, rests II1 are provided adjacent rolls 1 and the pieces when first placed in the machine can be placed on these rests which will take the shock if the pieces are not placed in position as gently as they should be, and it is contemplated that the rests may be formed of a material which is sufliciently softer than that of the work pieces that any damage such as denting of the surface will take place on the rest, and not on the work piece. The piece after being placed on rests II 1 may be moved into engagement with rolls 6 and 1, and rolls 8 brought into position without danger of further damage. Rests II1 are provided with downwardly projecting bifurcated portions II8 which in the present instance are identical with portion 89 above described, adjustment of the rests to the proper heights relative to rolls 1 being effected by a grip H9, and the adjustment maintained by a, lock nut I20 in the manner described for members 89. Other expedients may be utilized for obtaining this adjustment, and it is not essential to the invention that the adjusting means of the rolls 6 and 1 and rest II1 be identical, although it is preferable, for convenience in manufacture.

As above explained, roll 8 is carried by mechanism including a bracket 31 which is pivoted on a pin I2I extending in the present instance between webs I22 and I23 extending forwardly on frame 81, as particularly shown in Figs. 2 and 12, the bracket having a seating surface I24 contacting a complementary surface on the frame when the bracket is in its uppermost position, corresponding to the operative position of roll 8. Bracket 31 has an enlarged portion I25 at its upper end which is slotted to receive a shank portion I26 constituting part of above mentioned contact mechanism I0. A cap or clamp member I21 may be forced into clamping relation to shank I28 by means of screws I28--I28 to rigidly maintain the shank in desiredadjusted positions relative to bracket 31. A quick-acting clamp element is provided for maintaining surface I 24 of bracket 31 seated against its complementary surface on frame 81 comprising in the present instance a bifurcated lever I29 including bracket 31 between its arms, and pivoted to the bracket by means of a pin I30 or the like, the arm having cam portions I 3I and I32 exteriorly thereof engaging respectively cam portions I33 and I34 extending toward the arm I29 from webs I22 and I23, the complementary cam surfaces urging the bracket forcibly against its seating surface on the frame when the arm I29 is swung downwardly. A rod I35 may be run through suitable bores in the outer ends of adjacent arms I29 if desired so that several arms may be operated simultaneously, and one or more of the arms may be provided with set screws such as I36 which may v be tightened to prevent displacement of the rods. To provide an adjustment to permit simultaneous taking up of the arms I29 the pins I30 are made with an eccentric middle or journal portion I 31 as more particularly shown in Fig. 13a. Rotative adjustment of the pins will accordingly change the adjustment 'of the cams I3I and I32 independently of those of other bearings connected by rod I35. Other expedients are contemplated for quickly clamping and unclampin-g brackets 31 as within the realm of the invention, the disclosed structure serving the purpose of allowing rapid opening and closing of the bearings for quickly placing in position work pieces to be tested. As the bearing members are changed in position, the rod I35 slides freely through the bores in arms I29, and if any of the bearings are to be removed or replaced, the rod is first removed from, the arms, and after the desired change has been made the rod is replaced.

The construction of contact mechanism I is shown in Fig. 13. Shank I26 has a longitudinal guiding bore I38 in which is slidably guided a plunger I39 which is preferably made as light as possible by boring out as shown at I40, the plunger carrying at its lower end a transverse web I4I having ears I42 and I43, Fig. 14, carrying roll 8 between them by means of a pin I44 on which the roll is journaled. Pin I44 may be fixed in position by any suitable means such as a pin I45. Web MI is spaced a small amount from the end of shank I26 to provide a clearance I46 to permit movement of plunger I39, but the clearance is preferably of an amount corresponding to a maximum desirable movement of the plunger so that deflections. of the work piece which cause movement of the roll 8 and its connected parts will be positively limited by the amount of the clearance.

The outward movement of the plunger is limited by a pin I 41 fixed transversely of plunger I39 and received in a slot I48 which is of sumcient extent to permit the desired movement, the slot preferably'exerting a guiding action to main= tain roll 8 in a plane substantially parallel to anydiameter of the journal being tested. Pin I41 may be prevented from moving axially in plunger I39 by any suitable means such for example as a set screw I 49.

Movement of plunger I39 caused by deflections of the work piece is resisted by a compression spring I 50 also guided in bore I38, the spring being urged into contact with theend of the plunger by means of a threaded rod II engaged in a threaded bushing I52 fixedfor example by a set screw I53 in a hub or barrel portion I54 of a cover member I55 which is fixed on a housing I56 by suitable means such as screws I51. Rotation of the rod will accordingly change the degree of compression of the spring, and'consequently the amount of pressure necessary to produce movement of plunger I39, and such rotation may be effected by means of above mentioned grip or cap member I2. The cap and barrel I54 are preferably graduated as above mentioned and as shown in Fig. 2 so that any desired pressure may be immediately developed in spring I50. To compensate for variations in springs I50 as manufactured, and for providing various ranges of pressure in the same structure, spacers such as I58 are preferably inserted in bore I38 between spring I50 and rod I5I, the spacers furnishing a means of changing the compression in the spring for any given setting of the cap I2.

Movement of plunger I 39 is caused to control an electric circuit, as briefly outlined above, and for this purpose pin I41 has threaded thereto, or otherwise fixed therewith an actuating rod I59 extending upwardly through a bore I60 in shank I26 and having apointed end portion I6I engaging one or another of suitable sockets IBIa and Hill), Figs. 16 and 1'1, disposed on opposite sides of sockets I63a, mentioned below, in a contact lever element generically designated by numeral I62 composed in the present instance of two sections I63 and I64 riveted or otherwise -flxed together, but insulated from each other by tains mechanical contact between section I63 and rod I59, and owing to the construction employed the lever arm between the fulcrum represented by screws I66 and I61 and the point of contact of rod I59 may be made very short. Very slight movements of rod I59 are therefore multiplied at the free end of lever I62 to appreciable amounts.

The reason for providing two sockets I6Ia and I6Ib is to make possible the use of the contacting mechanism with various types of indicating mechanism described below, certain'of which operates to better advantage with the contacts normally closed and opening upon deflection of the work piece, and certain of which requires the contacts to be normally open and to close upon deflection of the work piece. With rod I59 in socket I6Ia, as shown in Fig. 1'1, and spring I68 acting downwardly, the first situation is established, and with the rod in socket I8Ib as shown in Fig. 16, and the spring acting upwardly, the second situation is established. The flexibility of rod I59 and the size of bore I69 are such as to permit the slight misalignment of rod I59 which occurs when it is changed from one socket to the other, the distance between the two being very slight, and shown much exaggerated in the drawings.

Other bearing constructions are contemplated for the lever arm, those shown being chosen as illustrative merely. The outer ends of screws I66 and I61 are in the present instance arranged to be covered by the edges of cover plates I69 and I18, which are arranged to close in the open sides of housing I56, being held in place by screws or the like such as I1I.

- Section I64 is provided at its free end with a contact point I12 which is arranged to cooperate with a complementary contact point I13 in the present instance fixed on the end of an adjusting screw I14 threaded in a bushing I15 insulated from housing I56 in any suitable manner as by an insulating bushing I16, a grip I11 permitting adjustment of the screw, and a lock nut I18 acting against the bushing I15 to maintain any desired adjustment. ,Electrical connection to the bushing and accordingly to contact point I13 is made in the present instance through a binding post of conventional or suitable character generally designated by numeral I19 also insulated from housing I56 by an appropriate bushing I88 and washers I8I and I82. Electrical connection may be made to contact point I12 through spring I68 which is connected at its end remote from section I64 with a conventional or suitable binding post I83 which is also insulated from housing I56 by a bushing I84 and washers I85 and I86 Thus if the contacts are to be used as part of a two-wire circuit, connections can be had to the two points independently of the frame of the machine, whereas if a one-wire circuit is to be used it isonly necessary to connect one or the other of the binding posts I19 or I83 with the frame, or omit the insulating washers from one of the posts. It is contemplated that the contacting mechanism will be'used with different types of indicating apparatus requiring both types of circuits, and it is desirable to be able to use the same contactor structure with either type. For use with a one-wire circuit lever I62 might be conveniently made in one piece, or insulation I65 might be omitted, and other such variations will suggest themselves to those skilled in the art, and are contemplated as within the scope of the invention.

For convenience in moving shank I26 in bracket 31 to accommodate journals of diflerent sizes, a screw I81 is provided journaled in a bearing portion I88 extended from shank I26, the screw being prevented from moving axially relatively to the shank by means of a collar I89 received between bearing I88 and a portion of cover member I55. Screw I81 is engaged in a threaded bore in bracket 31 adjacent the slot through which passes shank I26, whereby rotation of the screw will cause movement of the shank at such times as clamp portion I21 is out of clamping engagement therewith, and a lock nut I90 on the screw may be tightened against bracket 31 to maintain various adjustments of the parts. For rotating the screw an extension I9I projects above cover member I55 for the reception of a removable key, crank, or the like I92 which fits thereon and engages a transverse pin I 93 fixed in the extension.

From the above it will be understood that with roll 8 in contact with a work piece supported on rolls 6 and 1 any deformation of the piece will cause movement of roll 8 and plunger I39, the movement being multiplied by lever I62 and making or breaking any circuit that may exist through contacts 112 and I13. Any desired amount of resistance may be offered to such movement by spring I58, and the amount read directly from the graduations on cap I2 and barrel I54. Adjustments may be made also at the contact points by means of screw I14, and the position of the roll 8 may be adjusted by means of screw I81. The maximum possible deformation of the piece is determined by the clearance I46 which is preferablysmall enough to prevent any dangerous distortion, but in practice the spring I58 would normally be tightened to a point where it would prevent movement of the plunger through the whole of the clearance space. From the spring pressure necessary to do this the magnitude of the unbalanced forces in the work piece can be determined as outlined above, and from the position of the piece when its deflection causes movement of the contacts, the angular location of the unbalanced Weight can be determined with one or another .of the following indicating devices.

The device II shown in position on the machine in Fig. 1 is shown in detail in Figs. 18 and 19 and comprises a stroboscopic device in which a disk I94 is driven in synchronism with the work piece 4, and flashes of light from a discharge tube or the like I95 produced upon opening of the contacts I12 and I13 at one of the bearings 5 are observed through an opening I96 in the disk. Since the disk is synchronized with the work piece, as also are the breaks in the circuit caused by the deflections of the piece, the opening appears to remain stationary, and the position which it takes up gives an index of the location 01' the heavy spot in the work piece.

This apparent position may be noted for future reference against a suitably graduated scale I 91.

Disk I94 is driven from above mentioned shaft 19 through a lag compensating mechanism generally denoted by numeral I98, Fig. 6, the disk being fixed with a shaft I99 carried in a bearing 290 supported from a portion of a housing 2M arranged to enclose the indicating mechanism. Shaft I99 is maintained against axial movement by a head portion 292 to which disk I94 is attached by suitable means such for example as rivets 203, and by a collar 204, the head and collar engaging opposite ends of the bearing. Hous- 7 ing I provides an annular rim 205 which projects inwardly to within a short distance of the periphery of disk vI 94, and carries above mentioned scale I91. Rim 205 carries behind disk I94 a translucent member 206 which may be held in place by any suitable means such for example as a flange 291 against which the member is held by a spring wire ring 208. Member 206 will distribute the light from tube I 95 so as to uniformly illuminate the opening I96 and make reading thereof easier. A ring 209 fixed with housing 29I by suitable means such as screws 2H] may be utilized to hold a glass or other transparent closure 2| I which may be spaced from scale I91 and disk I94 by a gasket or other spacing means 2I2, thus excluding dirt, and protecting the operator from any danger due to the rapidly rotating disk.

Tube I95 is excited from a coil 2I3 having primary and secondary windings 2M and 2I5, Fig. 20, of suitable orwell known type, and suitable connections extend from the secondary to the tube, for example, one terminal of secondary M5 is connected to one terminal 2I6 of the tube by means of -a flexible lead 2I1, the lead containing suflicient slack to permit removal of coil 2I3 from housing 20I by removing screws 2 I 8, and being connected to the coil through a quick-detachable plug 2I9 of suitable or well known type.

The other secondary terminal is preferably connected with the coil housing so that the secondary circuit may be completed through the metallic parts of the machine from the other terminal 220 of the discharge tube I95. Current reaches the primarywinding of the coil 213 through a flexible cable 22I containing conductors 222 and 223, Fig. 6, the circuit arrangement being more particularly shown in the wiring diagram Fig. 20.

The circuit illustrated shows a two wire system, and the apparatus has been arranged with this type of circuit in view, but it is to be understood that a one wire system could be used in lieu of that shown with some consequent simplification of the apparatus, one of the wires being replaced by the metal parts of the machine. Since this practice is Well understood in the electrical art, and since the adaptations necessary could readily be performed by one skilled in the art, the disclosure will be confined to the two wire system, but it is to be understood that this is not to be taken as limiting the invention to the details of the circuits disclosed, or in fact in any manner except as defined in the claims. I

As shown in Fig. 20, current may flow from generator I4 through lead 223 for example to the primary coil 2I4 constituting part of coil 2I3,

leaving the primary through lead 222, the current then flowing through a lead 224 extending the length of the base I of the machine. From this lead the current flows through one or another- I12 and I13, screw I14, and returning through one of leads 221-221, a switch 226 and a lead 228 to generator I4. So long as a steady current flows in the above outlined circuit there will be no voltage induced in the secondary 2| 5 of coil 2I3, but if the circuit is broken through separating of contacts I12 and I13 caused by deflections of the work piece or by otherinfluences, a momentary high voltage will be induced in the secondary in familiar manner and a momentary excitation of tube I95 will take place. This will have a definite time relation to the deflection of the work piece, and will serve to momentarily illuminate the opening I96 in disk I94, and since the disk rotates in definite relation to the work piece, and is illuminated once in each revolution thereof, and always at the same point in its revolution, the opening will appear stationary at some definite point in its travel indicative of the position of the heavy spot in the work piece. The apparent location of the opening may be noted, after which'the machine may be quickly stopped by means of brake lever 56, and the work piece rotated by hand or otherwise to the position where the opening I96 is returned to the' position observed when it was rotating, when the work piece will be in the position which it occupied at the instant the deflection took place.

Any convenient expedients may be used in providing the circuits outlined, and variations or additions known to those skilled in the art may be made, such for example as a condenser 229 connected across primary 2l4. In practice the leads are preferably carried in protecting conduits where possible, as more particularly shown in Fig. 1, leads 222 and 223 being housed in flexible conduit 22 I, and leads 224 and 228 being extended along the front of the machine in a conduit 230, the conduit being provided with outlets 23I-23I of suitable or standard type by which connection may be established with the leads within. Leads 225 and .221 are contained in flexible cables 232-232 which are provided at their ends with terminal plugs 233233 for ready connection with the outlets 23I-23l, and switches 226-226' are interposed in the leads between the plugs and the upper termini of the leads as more particularly shown in Fig. 12. This arrangement permits the locating of bearings 5 wherever desired, after a bearing is placed, its cable 232 being plugged bearing the hands may be moved to the values noted, and observations made at as many of the remaining bearings as desired before the machine is'stopped, after which the work piece may be immediately placed in the position at which deflection took place at any desired .bearing by noting the setting on its dial 234. The speed of rotation at which this deflection took place'may also be read oil the dial, and the force necessary to substantially balancethe deflecting tendency may be read from the position of cap I2. The piece may be marked at each journal with H maintain its position.

above mentioned shaft .19.

this-data, including the location of the excess weight, the necessary calculations made and the appropriate amount of material removed at each location, whereupon the piece will be in substantially perfect balance as outlined above.

It is understood that in apparatus of this nature there is a certain amount of lag in the electrical or other portions of the device, and ,to avoid the necessity for including this in the calculations, above mentioned lag compensator I98 is provided. This device is shown in Fig. 6 and comprises a speed responsive device mounted on The shaft is journaled in a bearing 23! fixed with a portion of housing 45, a closure 238 carrying a second bearing 239, the two bearings engaging the end portions of gear 18 and preventing axial displace ment of the shaft. Shaft 19 has fixed therewith upwardly of bearing 23! a yoke member 240, the

yoke being threaded on the shaft in the present instance and-provided with a lock nut 24! to Yoke 240 has pivoted thereto by means of suitable pins 242-242 arms 243-243 carrying weights or fly-balls 244-244 which tend to swing out from the shaft as rotation takes place. The swinging movement is resisted by links 245-245 pivoted adjacent the weights by means of pins or the like 246-246, the links being pivoted at their other ends to a sleeve 24! slidably keyed to shaft 19, by means of a feather key or the like 248, pins 249-249 serving to connect links 245 with the sleeve. Shaft 19 terminates within sleeve 241, and above mentioned shaft I99 extends downwardly from indicator II into the sleeve and is driven therefrom by means of a pin 25!) fixed in the shaft transversely thereof and engaged in a pair of opposed slots 25!, one of which is shown in Fig. 19. Axial movement of the sleeve is produced by outward movement of weights 244, and this is caused to effect the desired compensation by shaping slots 25! to cause relative rotation of shafts I99 and 19 of an extent determined by the amount of lag observed at various speeds in any convenient manner, as for example when a work piece is tested having a heavy spot of known location. 'Axial movement of sleeve 24'? is resisted by a spring 252 disposed about shaft 19 and compressed by an adjusting nut 253 threaded on the shaft, and by means of which adjustments of the spring force may be accomplished. Through the action of this device the position observed on the indicator I! is always the true position of the work piece obtaining at the instant the'deflection takes place, and not a value which must be corrected to determine the actual position. The compensator may be reached for assembly, adjustment or the like through an opening covered by a closure 254.

In addition to the means just described for indicating the angular position of unbalanced weight in a work piece, other indicating means is contemplated and may be used within the scope of the invention. In Figs. 21 to 24 inclusive a sys tem is shown which among other advantages avoids the-use of high voltage. Referring first to Fig. 24, the system includes a plurality of incandescent lamps 255-2 55, preferably arranged in a ring-shaped group and connected in series with each other by connections 256-256. Current is supplied from generator !4 through a lead 25! at one or more points 258, and divides and flows around the group from each point in two directions as indicated by the arrows, and leaves the group at a plurality of points 259, returning to the generator through a lead 260. The group of lamps is accordingly divided into a plurality of series, and the number of series and the number of lamps in each may be chosen in accordance with the voltage of the generator and the voltage of the lamps it is desired to use. In the working embodiment described below, for example, it is contemplated to use one lamp for each three degrees in the circle, or 120 lamps. These are divided into six series of 20 lamps each, there being three taps corresponding to taps 258 and three corresponding to 259 on the complete ring. With a generator giving 110 volts, this would result in an effective voltage on each lamp of five and one-half volts.

The lamps are arranged to be successively momentarily short circuited whereby, owing to the time lag between beginning of current flow and attainment of normal brilliancy present in incandescent lamps, they will not reach their full brilliancy, but will burn somewhat more dimly than they would if operating on a steady current. The short circuiting means includes a commutator 26!, each of the segments 262 of which is connected with one of the connectors 256 by means of a lead 263. Connecting of any two adjacent segments will thus short circuit the particular lamp, which happens to be between the conductors 263 connected with'the adjacent segments. The connecting may be done by a rotating member 264 driven in synchronism with the work piece and carrying a pair of spaced brushes 265 and 266, insulated from each other,

contacts !12 and H3 are opened by deflection of the work piece or otherwise. Since such opening of the contacts will take place once during each revolution, and always at the same point in each revolution, the short circuit will be constantly broken at the time member 264 is in contact with a certain pair or group of segments in commutator 26!, with the result that the particular lamp or lamps controlled by those segments will not be short circuited, but will receive. a steady uninterrupted supply of current at full voltage. The lag effect will not be present in this lamp, and it will burn with its full brilliancy, standing out from among the dimmer lamps, and marking the location of the work piece at the instant deflection takes place.

It is to be noted that the brilliancy time lag effect in incandescent lamps generally disqualifies them from uses relating to apparatus of the character of this invention, but in this device this lag is taken advantage of in the working of the device, and it is contemplated that the old style carbon filament lamps would be satisfactory in the present indicator, and possibly superior to the tungsten or other more advanced types.

In the working embodiment shown in Figs. 21 to 23, the device is enclosed in a housing 26'! which is supported in the manner of housing 20! from the head-stock, the mechanism being driven from the lag compensator sleeve 24'! in the same manner as indicator II, a shaft 268 carried in a bearing 269 extending to the sleeve and being driven therefrom by a pin 21!]. Shaft 268 extends forwardly in housing 26'! and has fixed therewith the rotating member 264 cooperating with commutator 261, the lamps 255 being supported in a socket carrying member 211, and the readings taken against a scale 212 the graduations of. which approach as nearly as practicable to the lamps 255, as particularly shown in Fig. 21.

commutator 261 comprises in the present instance a plate 213 of insulating material about which a clamping ring 214 clamps a series of segments 215-215, the segments having dovetailed projections 216 which are gripped between the plate and the ring when the latter is forced toward the plate by suitable means such as screws 211, certain of the screws 218 passing through the plate into housing 45 to maintain the plate in position. Segments 215 may be slightly spaced from each other or separated by insulation 219' in the manner well understood in commutator construction. Slip rings 286 and 281 are mounted on the face of disk 213, being held in place by screws or the like such as 282'and 283 respectively, suitably spaced about the lengthpf the rings.

Member 264 in the present instance is formed of insulating material, and is'slotted at 284 and provided with a, clamping screw or the like 285 by means of which the member can be rigidly secured on the shaft in any desired relation thereto. The member carries above mentioned "brushes 265 and 266, the brushes being disposed in the present instance in substantially radial slots such as 286 formed in the end of themember and spaced the desired distance from each other, preferably the center-to-center distanceof the segments 215. Brush 265 is fixed on a fiat spring 281 which maintains the brush in its slot and yieldingly presses it against the inner surface of the commutator 261, the spring also being fixed with member 264 by screws or the like 288, and extending toward shaft 268 and having a portion pressing on a brush 289 slidablein ,a suitable bore in member 264 substantially parallel to shaft 268, and pressing the brush into contact with slip ring 286. In a similar manner a spring 296, also fixed with member 264 presses brush 266 against commutator 261 and connects with and presses a brush 291 against slip ring 281. Connection may accordingly be established with rotating brushes 265 and 266 by merely connecting with slip ringsw 286 and 281.

Socket carrying member 211 comprises an annulus of suitable insulating material seated in housing 261 against a shoulder 292, the annulus having a forwardly projecting rim 293 against which dial 212 is secured for example by screws such as 294. Socket member 211 is provided adjacent its periphery with a series of bores 295-295, Fig. 23 for the lamps 255, each bore being provided with a threaded'bushing 296. after the manner of a conventional lamp socket, and each' bushing has a finger 291 fixed therewith andextencling into a position behind and approximately axially of the bore of its next adjacent bushing. Each bushing therefore constitutes an individual lamp socket with the help of the finger fixed with the next adjacent bushing, and when the bushings are filled with lamps as shown in Fig. 23, the lamps are connected in series without resort to other connections. This arrangement is of course for use with lamps of the screw base type and constitutes a means for holding the lamps and establishing 'the desired connections in a simple and convenient manner. Other expedients are contemplated as equivalent and if it is desired to use other types of lamps adaptations therefor may be made by those skilled in the art within the province of the invention.

In the illustrated structure wherever it'is desired to establish connections with the series between the lamps as shown in the diagram it is conveniently done by connecting a conductor with one of the fingers 291 as by soldering or the like. Thus conductors 298-298 are so connected with each of the fingers 291 and each conductor is also connected with one of the segments 21 5, adjacent fingers 291 being connected with adjacent segments'preferably by soldering or the like so that the act of connecting adjacent segments will short circuit one of the lamps 255 for the purpose above explained.

Current is supplied to the lamps by means of leads 251 and .266, which are enclosed in a flexible cable 299, similar to above described cable 221, the leads coming directly from generator 14 through appropriate conduits as shown in Figs. 22, and 1. In order to avoid the necessity for an excessively high voltage in generator 14, the group of lamps is divided in the present instance into a plurality of series, leads 251 and266 being connected respectively to conductors 366 and 361, disposed around the interior of the housing adjacent to fingers 291,-and constituting feeders for the series of lamps. Feeder 366 has a plurality of branches 362, in the present instance three, connected'as above noted with fingers 291 at equal angular intervals about the group, while feeder 361 has similar branches 303 also connected with fingers 291 at points midway between branches 362. This arrangement divides the lamps into six independent series, and gives convenient values the scope of the invention.

Leads 224 and 228 in this embodiment are extended from conduit 236 through conduit 299 and connected respectively with slip rings 286 and 281. The action of contact points 112 and 113 accordingly determines when the electrical connection between brushes 265 and 266 will be interrupted, and the position of the member 264 at the time this connection is broken will determine which of the lamps 255 will receive a continuous supply of current and therefore burn at full brilliancy.

Shaft 268 carries a pointer or the like 364 which is utilized after the machine is stopped to permit returning the work piece to the positions observed by means of the lamps, and if desired a manually movable index 365 may be provided to assist in the observation of the angle indicated by the lamps that are bright- The housing may be closed by a glass or other transparent member 366 held in place by a ring 361 secured on the housing by suitable means such as screws 368, the glass seating in the present'instanceagainst a liner 369 slidable in housing 261 and bearing against socket member 211. This furnishes a convenient means 6 would facilitate determining the mid-point of the bright portion of the group, which would be' the desired reading. Such an index might be applied to the indicator disclosed in Figs. 18 and 19 within the scope of the invention.

Other means are contemplated for indicating the angular location of the work piece at the instant of deflection, and an illustrative example of another type of indicator is shown in Figs. 25, 26, 27, and 28. In this arrangement a pointer is fixed at the instant of deflection of the work piece with a shaft portion which is rotating in synchronism with the work piece, the shaft portion being then stopped, the relation of the pointer therewith read, and the shaft reengaged with the mechanism for another reading.

As seen in Fig. 25, a shaft portion 3I3 is driven from sleeve 241 of lag compensator I98, the shaft being provided with a pin 3I4 engaged in a slot 3I5 shaped to provide the desired correction for lag as explained in connection with the above described indicators, shaft 3I3 driving, through a jaw-clutch generically designated by numeral 3 I6 a shaft portion 3", the shaft portion having an internal tapered seat-3I8 within which a complementary tapered element or bell 3I9 may be seated by means of an impulse from an electromagnet 320, the bell element carrying a pointer or index 32I indicating against a scale 322 rotating with portion 3 I I.

Shaft portion 3I3 is carried in a suitable bearing 323 suitably retained in a partition or the like 324 constituting part of a head-stock similar to head-stock 3, by suitable means such as a ring 325 held by screws or other suitable means 326; the shaft being also maintainedin alignment by its sliding engagement in sleeve 241. Shaft 3I3 terminates at its left end as seen in Fig. 25 in a head 321 forming part of the clutch 3I6. Shaft portion 311 has a reduced pilot portion 328 extending into a suitable bore in portion 3I3, through which portion 3I1 receives support from bearing 323, the pilot portion serving to further assist in aligning portion 3I3. A clutch member 329 is slidably keyed on portion 3I1 and forced into yielding engagement with head 321 by means of a spring 330, and head 321 is provided with a groove or channel 33I Fig. 26"'of a 'wide V shaped cross section, the channel being transverse to the axis of the clutch member but displaced from the axis as shown. Channel 33I is engaged by a rib 332 of complementary cross section and position on clutch member 329, through which the clutch member and its connected parts are driven from shaft 3I3.

Owing to the radial displacement from the axis .of the clutch member and shaft, the rib and groove will fail to register in any but one position, and as a result, shaft portion 3I1 will always be engaged in the same angular relation with shaft portion 3I3 when the clutch is engaged. If shaft portion 3I3 is rapidly rotating when the clutch is allowed to engage there will be no shock, but rib 332 will fail to enter groove 33I under the urge of spring 330, sliding on the surface 333 of the Head 321 until clutch member 329 has attained substantially the same speed as the head 321,

when the rib will engage the groove and a posi tive connection will be established. Clutch member 329 is provided with an annular groove 334 engaged by a pin or the like 335 carried by an arm 336 fixed on a shaft 331 journaled in a bearing 333 carried by a wall of a housing 339 forming part of the above mentioned head-stock, the shaft extending outside of the housing and having fixed therewith a lever 340 provided with a pad or grip 34I for manual manipulation. Depressing of lever 340 will stop shaft portion 3I1 and permit reading of the dial 322, and releasing it will permit reengagement of clutch 3I6 preparatory to another reading.

Shaft portion 3I1 is provided with a keyway 342, and is enlarged at 343, providing a shoulder 344 against which spring 330 bears. Enlarged portion 343 has a bore 345 in which is disposed a sleeve portion 346 carrying above mentioned seat 3I8. The sleeve may be threaded into the bore at 341 or otherwise suitably fixed therein, and provided with a head or flange 348 serving to retain a suitable bearing 349 preferably of an anti-friction type in position on the portion 343. Bearing 349 is carried in a partition 350, and retained therein by means of a plate 35I held by screws or the like 352. Bearing 349 serves to support shaft portion 343 and dial 322, and with bearing 323 maintains the parts in position against the thrust of spring 330. This construction is satisfactory particularly since the spring 339 is fairly light, but other well known or suitable arrangements might be adopted within the scope of the invention in which the spring thrust is not transmitted to the bearing supporting the mechanism. Dial 322 is fixed with head 348 by suitable means such as screws 353.

Bell member 3I9 has a neck portion 354 journaled on a pin or rod 355 projecting into sleeve 346, the neck portion carrying an armature member 356 disposed within the field of magnet 320, and pointer 32I is preferably fixed with the armature and extends beyond the periphery of dial 322 in the present instance so as to contact, at such times as bell 3I9 is disengaged from seat 3I8, a pin or the like 351 fixed with a portion of partition 350. Pointer 32I is preferably provided with an indicating point 358 spaced from pin 351 toward the axis of dial 322 for convenience in reading against dial 322, and pin 351 may be provided if desired with an indicating point 359.

After engagement of hell 3I9 with seat 3I8, pointer 32I will occupy some definite relation to dial 322, and after these indications have been read and noted for all the journals on the work piece, the piece may be stopped, and rotated by hand or otherwise with clutch 3I6 engaged until the various values are indicated against point 359 when the piece will be known to be in the position in. which deflection took place at the particular journal for which the particular value was noted.

Magnet 320 includes a core 360 on which is disposed a coil 36I, the coil being connected with other portions of the operating circuit by leads 362 and 363 enclosed in a flexible sheath 364. Core 360 is secured in a suitable bore in a bracket 365 secured to portion 339 by screws or the like 366, the core having a nut 361 thereon for clamping it in the bracket. .Pin 355 is slidable in a suitable bore axially of core 360 as shown and has an enlargement 368 arranged to encounter armature 356 when the pin is moved to the right as shown in Fig. 25, for the purpose of dislodging bell 3I9 from seat 3! after a reading has been secured. A knob or the like 369 is fixed with rod 355 for convenient manipulation thereof.

For use with this type of indicator the contact elements I12 and I 13 are arranged in the Open. circuit" position as above explained and shown in Fig. 16, and the connections are as indicated in the wiring diagram Fig. 28. Starting with generator I4 the circuit leads for example armature 356, and stick bell 3I9 in tapered seat 3I8, thereby locking pointer 32l in the relation with dial 322 corresponding to the position of the work piece at the instant of deflection, pointer 32! moving to the left out of engagement with pin 351 upon movement of armature 358.

Whatever lag is present in the mechanism is compensated by retarding dial 322 relatively to the work piece by means of. device I98 above described, slot 315 being contoured as necessary to suit the characteristics of the mechanism as determined by experiment with a weighted work piece or otherwise;

In addition to providing means in the machine for determining the location and amount of unbalanced weight in a work piece means is provided for correcting .the unbalance by removing material from the work piece while it is still in the machine, it being then possible to re-test the piece after the correction has been made. The particular arrangement ofthe supports 89 makes this readily possible, the work piece being firmly supported at closely spaced points.

Various apparatus might be utilized for this purpose, but in thepresent instance a milling head of suitable or well known type is used which may carry a suitable tool such as a milling cutter, drill, grinding wheel or the like, and which may be moved into position to operate on various desired parts of the work piece. As shown particularly in Fig. 29, the mechanism used in the present instance includes a channel member 31l fixed with the rear wall of base I by bolts or the like 312, the member being provided with suitable guides 313 and 314 on which is slidably mounted a column or support member 315, extendingaupwardly and provided with spaced guides 316 and 311 against which is slidably mounted a carriage 318. Carriage 318 has an arm 319 projecting forwardly over the machine and having spaced guides 388 and 38l on which is slidably mounted a carrier 382' which carries a spindle carrying head 383 in the present instance angularlyadjustable about an axis transverse to that of the work piece. 'Head 383 carries a tool spindle 384 on which may be fixed a cutter of a type to suit the work in hand. Since the particular construction of the milling machine portion of the apparatus is not a part of the present invention, and since the details of such apparatus are generally well known, the gearing, power trains, clamping mechanism, etc. are not shown in de tail, and do not need to be completely described for a full understanding of the invention.

Sufficient to say, gibs 385 and 386 are provided .for securing proper running fits between guides 313 and 318 and the adjacent portions of column 315, a screw 381 or the like extends through the column between the guides and may be engaged by suitable mechanism not shown for sliding the column along the member 31!, and a screw 388 is arranged for raising and lowering carriage 318.

A shaft389 projects from the forward end of arm 319 and is squared for the reception of a crank or the like of familiar type, not shown, the shaft having suitable connections for rotating and the carriage may be clamped in adjusted position by means of bolts 398-398. Carriage 318 carries a motor or other power source 3!", a transmission means 392, a rate changer 393 and certain other apparatus which will be described presently. Power is transmitted to head 383 by means of a shaft 394.

(Farrier 382 may be clamped in adjusted position by suitable mechanism actuated by handles 395-395, and head 383 may be clamped by means of a handle 396. A shaft 391 projects from the forward portion of arm 319 and is squared for the reception of a crank or the like of. familiar type, not shown, there being suitable connections within the arm and column for sliding the column by means of screw 381, and a shaft 398 of similar character projects from the arm and has suitable connections for sliding carrier 382 along arm 319. Spindle 384 may be fed up or down through suitable mechanism of well known type by means of a hand wheel 399. It may accordingly be brought to bear upon any desired portion of a work piece and at any angle required by the previously determined location of the unbalanced weight.

For convenience in accurately determining the depth which a cutter has reached a dial indicator is provided as follows: Spindle 384 is carried in a long quill 399a extending upwardly from the head 383, and a dial indicator of suitable or well known type 399?), Fig. 29a, is adjustably fixed therewith by means of an extension 3990 clamped therearound by suitable means such as a thumbscrew 39911. The indicator has in the present instance a hand 399e, a. counter 399i, and a stem 3999, the latter positioned to contact a pad 399h on head 383 through which the indicator mechanism is actuated by movement of the quill 399a. The cutter or drill may accordingly be set in contact with the work, after which extension 3980' may be clamped in a convenient position on quill 399a, the progress of. the cutter into the work then being accurately indicated on the indicator 39%. Other means might be utilized for supporting the indicator in proper relation to the spindle, and any such are contemplated within.

the scope of the annexed claims.

For accurately determining the actual amount of material removed from a work piece weighing means is provided. A suitable cutter 488, with spindle 384, is enclosed in a box or chamber 48! which is connected by means of a flexible or other suitable conduit 482 with the .intake 483 of a suction fan or the like 484 driven in the present instance by a shaft 485 from a suitable portion of transmission 392. Substantially all the material removed in the form of chips by cutter 488 is picked up by the current of air running through the box MI and conduit 482, and discharged from the fan through a pipe 488 into an extractor of centrifugal or other suitable type 481, from which it drops onto a pan 488 suspended by chains or the like 489 from an arm 8 of. a scale mechanism of suitable type enclosed in a housing 4i i, the weight being indicated on a dial 2. Since movement of the chips through the system is very rapid, the chips accumulate on pan 488 substan-

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