US2620602A - Polishing machine - Google Patents

Description

Dec. 9, 1952 c. a. SCHENK POLISHING MACHINE 2 Sl-IEETS-SHEET 1 Filed July 1. 1949 INVENTOR CHARLES q: scum/ c. G. SCHENK POLISHING MACHINE Dec. 9, 1952 2 SI-lEETS-SI-IEET 2 Filed July 1. 1949 721 Sou/2c: 0F

PREssaRE FIG. 2. /0

FIG. 5.

ATTORNEYS Patented Dec. 9, 1952 OFFICE POLISHING MACHINE Charles G. Schenk, New Britain, Conn, assignor 'to The Fafnir Bearin (701111., a corporation g Company, New Britain,

Application July 1, 1949, Serial No. 102,611

'6 Claims. 1

My invention relates to a polishing machine, and inparticular to a machine for automatically finish-polishing race'grooves of the inner rings of. antifriction bearings.

; It is an object to provide: an improved device of the character indicated;

It another object to provide a'm-achine for simultaneously polishing. a plurality of antifric- ,tiombearing race grooves at onetime.

It. is a further object to provide an improved finish-polishingmachine, wherein an automatical-1y performed polishing operation may consistently and uniformly finish-polish a plurality of successively chucked and a plurality of simultaneously chucked: pieces of work.

It is also an object to provide an improved ,automatic polishing machine wherein th cycle of operation may be reduced to a minimum.

It is still. another object to provide an improved machine of the character indicated wherein an accurately controlled. rough-polishing operation and. an accurately controlled finish-polishing op- ,eration may be automatically performed on the same work in a single cycle of operation.

' Other objects: and various further features of the invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said. drawings, which show, for illustrative purposes only, a preferred formof the invention:

Fig. 1-. is a plan view of a machine incorporatmg features of the invention and shown with certain parts broken. away and in section, the mechanism. being; in the polishing position;

Fig.2 is. asectional view taken more or: less in the planes of the line 2-2 of Fig. 1 and showing a side. elevation of a subassembly of themachine of. Fig. 1, parts of the mechanism being retracted away from thepolishing position;

Fig. 3 is aview in side elevation of a part of the mechanism of Fig. 1;

Fig. 4 isan enlarged fragmentary view in partial section of chucking means in the machine otFig. 1; and

Fig. 5' is an electric-wirmg diagram schematically illustrating an interconnection of elements inthe machine of Fig. I.

Briefly stated, my invention in a preferred'iorm contemplates an improved means for bringing a polishing belt into operating. relation with an artitle to be polished. The article to be polished may be revolubly mounted on a spindle which may rotate at relatively high speed, while the polishing belt may be driven at a relatively low speed; In the form to be described, I provide means whereby a plurality of polishingoper tions may besimultaneously performed with uniform accuracy. My machine may be automatic in its operation and may be readily adapted to or set up" for the roughpolishing and/or for' the d'isplaceable relatively 2 finish polishingof a number of difierenttypes and sizes of articles to be polished.- In theform to be described, abrasivemay be uniformly applied to the polishing means and the timing for such application may be closely controlled Referring to the drawings, my invention is shown in application to an automatic polishing machine for finish-polishing the ball-race grooves it of a plurality of rings ll, which may be the inner rings of antif'ri'ction bearings.v The rings Il may be mounted in end-to-endi axial adjacency for rotation with a spindle l2, shown supported in spaced. pillow blocks 1 3. The spindle 12 may be driven at relatively high speed by a motor'M: connected. as by a belt 15 between. puI' leys lit-I l. The polishing. means for the race grooves 0 may be a single length. of belting or. cordv laid In multiple loops between a plurality of drivepulleys or sheaves, [Sand av plurality of idler pulleys or sheaves 91, but in the formshown I employia separate polishing. belt or cord .29 stretched between each pair of pulleys l 8l=9. The polishing belts- Zll may obtain their drive from the same drive means as the spindle l2,'but, in the form shown, I have employed a second. motor 21 with suitable reduction-gearing means. 2'2-to drive the drivesheaves l8.

In accordance with the invention, the polishing belt or belts It may be automatically advanced to and retracted from a polishing" engagemem with the work .ll supported on the spindlefil; and, in the form. shown,v I achieve this relative movement by mountingithe entire assembly of polishing means within one framework, which is movable relatively to the framework which suppurtsthe spindle 2|: and its drivemeans'; Thus, the spindle l2 and the motor" l"4 may be relatively fixedly mounted upon a base member or frame 23, while thepolishing assembly may be mounted upon a frame-plate member 24 that is to the frame 23". Also in accordance with a feature of theinvention', Iprovide means for angular adjustment of the inclination of that partof' the polishing belt-or belts 20 which is to en'gage the-work.

To achieve advancing and retracting sliding movement, the frame 2E may be-slidabl y guided between dovetail. rails or guides 25 which: may be formed inor secured toamounting or base-plate member 26 In order ta -permit the desiredangular adjustment, the: base plate 26' may in turn be transversely slotted; as at 2"! at the locationsr for securing: the base plate 26-, asv by means of tighten ingbolts 28;. For a purpose which: will later be clear, I also prefer that thebase plate 26- shall be longitudinally adjustable with respect to the axis: of spindle t2,- and I: have thereforeinoluded longitudinal guide means 29' as a part of the main supporting framework 23.

Advancing. andaretracting movement ot the tion by means of a solenoid polishing assembly may be governed by a fluidpressure operated means in the form of a doubleacting cylinder 35, shown mounted on a bracket 3| carried by the longitudinally and angularly adjustable base plate 25. The actuating means 30 is shown to include a stem 32 locked to the carriage 24 for the polishing means.

As explained, all polishing means in the form shown is carried by the carriage 24. The idler pulleys or sheaves [9 may, therefore, be supported by bracket means 33 vertically adjustably mounted, as at 34 (Fig. 2), on a bracket 35 carried by or forming part of the displaceable carriage 24. The sheaves 19 may be of a plurality appropriate to the number of race grooves Hi to be polished, and, therefore, the mounting stud or arbor 36 on the bracket 33 may be of a length to accommodate a desired number and spacing of sheaves IS. A readily accessible securing nut 31 may permit removal and substitution of idler sheaves 19. In like manner, the drive shaft 38 to be driven by the reduction-gear means 22 may also be of sufficient length to accommodate a desired number and spacing of sheaves l8, and the assembly of these drive sheaves [8 may be secured by a readily accessible nut 39. In order that all belts 20 shall perform uniform polishing operations on the various race grooves II], I provide belt-tensioning means for each belt 25, and means for equalizing the tensioning forces applied to each belt 20. The various tensioning means may all be supported by a bracket 43 adjustably mounted on the bracket 33, and each tensioning system may utilize an idler roller 4! supported by the stem of a fluid-pressure actuated means 52. The various fluid-pressure actuated means may all be manifolded, as at 43, and the pressure within the manifold may be maintained, as by connection at 44 to a source of fluid pressure. In the form shown, the various fluidpressure actuators 42 for the belt-tensioning means are longitudinally adjustable, as in slots 45. along the bracket 40, in order that the tensioning elements may be positioned in true-running relation with the particular belt 20 to be fltensioned, as will be clear.

In accordance with a further feature of the invention, I provide means for application of abrasive to the belt or belts 20 as desired, and the application to all belts 20 may be uniform. The application means may comprise a longiitudinally extending wetting roller 41 rotatably supported between spaced arms 48 of a rockable assembly, pivoted as at 49 to the frame 24. The roller 41 may be partially immersed in a reservoir or pan containing a solution or suspension of abrasive. The supporting yoke 48 for the roller v l'l may be normally spring-urged (as by a tension spring 5| acting on a crank 52) in a downward direction, that is, in a direction away from contact with the belts 20. However, upon actua- 53, a crank extension 54 of the yoke 48 may be displaced to set the wetting roller 41 in abrasive-applying contact with the belts 20. In the form shown, the armature of solenoid 53 is connected by two links to the crank arm 54, and the upper link 55 may be adjustably secured, as by tightening a nut 55, in order to provide a selected application force for the roller 41 against the belts 23.

In order that the cycle of operations of my machine may be reduced to a minimum, I provide braking means for quickly arresting rotation of the spindle l2 upon completion of a polishing operation.- Such braking means may be solenoid actuated, and in the form shown I have employed internally expanding brake shoes 58 within the drive pulley i6 (see Fig. 3). The brake shoes 58 may each carry actuating pins 59 normally urged toward each other by means of a spring 60 and positioned to be spread apart and into braking contact with the pulley l5 upon actuation of a solenoid 6|. The armature of solenoid 5| may lift a cam or wedge member 52 to spread the shoes 58, as will be clear.

I have explained that my machine is applicable to the simultaneous finish polishing of a desired plurality and spacing of inner race grooves, such as the grooves 15 of inner bearing rings H. The supporting means for such a plurality of rings may include a chuck which may permit fast loading and unloading of unfinished and finished parts. In Fig. i, it will be seen that such chucking means may include a mandrel 65 upon which the pieces of work H are to be supported. The mandrel 65 may include an enlarged base or flanged portion 55 to be secured, as by bolts 61, to a flanged member 68 which may be threaded on the end of the spindle l2. A chucking stem 59 may be longitudinally slidable within the mandrel 55 and be normally urged to the right (in the sense of Fig. l) by spring means 10 within the flanged member 53. Spring action may be adjustably selected by means of a nut ll threaded on the end of the stem 59 to receive abutment of the spring 15. The outer exposed end of stem 69 may be recessed to receive a C-washer 12, to be urged by spring 15 into compressional abutment with the work sample at the outer end of the mandrel 65.

In an unchucking operation, an actuating rod i3 may be shifted by a manually actuated system including a crank '55 operating an eccentric 15. The eccentric may be connected to a crank 15, pivoted as at H to the frame 23, and the crank it, when actuated clockwise in the sense of Fig. 1, may longitudinally displace the actuating rod 13 against the action of spring 10. In order to provide minimum wear between the crank 16 and the actuating rod 13 (which may rotate with the spindle I2), I provide antifriction thrustbearing means 68 at the point of engagement between crank it and the actuator means 13. A turnbuckle 79 between the eccentric I5 and the crank i5 may serve for adjustment of the described chucking means, so as to provide a desired throw of the actuating rod 13 for each throw of eccentric 15. It will be clear that when the eccentric T5 is thrown in an unclutching operation, the stem 59 may be projected outwardly so as to free the C-washer 12 from abutment with the outer work sample H. The G- washer may then be manually removed so as to free all the Work samples.

A better understanding of my machine may be had from a description of a typical cycle of operation, utilizing electrically interlocked controls, as shown schematically in Fig. 5. In the arrangement of Fig. 5, all relays and solenoids, and both motors 15-2! are connected to the same source of electrical supply. In particular, a double-pole switch may apply line voltage across the normally open contacts of motorstarting relays 358! in readiness for a relayoperated starting of the motors; likewise, a double-pole switch 88 may supply line voltage for operation of the various relays and solenoids. It will be noted, however, that when the switch 38 is thrown, brake solenoid Si is the only solenoid to be energized so that, in the starting position theipolishing carriage. 24: retracted),v the. brake 58 is set against the? drum of? pulley It. to holct the spindle 1'2 at rest.

In the: system of. control: shown, Iv employ two: time-delay relays 88-439 first, to permit-selected determination of the period during which abra- SW6 should: be: appliedto the. polishing means (rough. polishing): and, second: to determine the period. of. subsequent pol-ishingrwithout abrasive (finish polishing) Both relays 89-9.9- are shown to include normally closed contacts, that is,. con tacts which will remain closed and which will not: beop'ened until after the lapse. of the selected time-,fo1loWin-g. an energizing of the delay mechanism; Such delay relays are well known in the art and, therefore, will not be; illustrated or de-- scribed mdetail herein. It will be noted: that when the main switch 88 is closed, the brake solenoid't-l isenergized. by way of the normallyclosed contacts of delay relay 9i and by way of a double-pole double-throw relay 9L which relay- Stlrw-ill' be in the. dropped. or lower position before the cycle of operation is initiated.

To initiate the cycle of operation, the starter button 92-: of a start-stop assembly 23 may be" pushed. to close a circuit to the delay relays 89-49; thereby initiating the selected timing intervals for each of these relays 39-bit; at. the same time the coil of the double-pole doublethrow relay- 91 may be energized to operate the st'artingrelays 86-81 for both motors Hi -21 and to energize the solenoid 94,. which may position the selector valve refer an advancing move ment N of the advancing-and-retracting means 31-4-2 A push of the starter button 92 may thusefifeot'ively simultaneously commence rotation of the; spindle I 2 andof the polishing means ill-"while dropping out the brake solenoid 6| in order to release the brake. At the same time, the polishing. carriage 24 may be projected into working position. I

Now, when the double 'pole double-throw relay al; was energized to establish connections in the up-positi'on,v line voltage was also applied across a. normally open limit switch 96 in series. with trie abras'ive-appryin solenoid 53. In Fig. 2, it will be seen that the limit switch '96 may be fixedly mounted upon the polishing base plate 26, and its follower roller 91" may be poised to intercept a part. of. the polishing carriage or a part carried thereby as said carriage is forwardly projected into work position. In the form shown, the follower roller 91 for the limit switch 36 may be depressed as it rides under the bottom of the abrasive-solution reservoir 50, as will be clear.

Thus, just. as the. polishing means 26 is about to engage or engages the work II, the solenoid 53 may beenergized so as to apply abrasive to the polishing means 20.

Withv the operations thus far described, it. will be appreciated that both delay periods have commenced to run and that abrasive or rough polishing has. been commenced merely upon depression of the starter button 92. If desired, the starter button may be released and the starting circuit effectivelymaintained closed by means of a holding' coil, but in the form shown, I have employed a second switch 98 having normally open contacts to be closed when the follower roll 99 thereof intercepts the reservoir pan 59 in a projected or advanced or working. position of the polishing means. If it is desired to'have an interval of polishing. without abrasive (finish-polishing in"- terval.) afte'ria given interval of polishing with abrasive (rough-polishing interval), the delay 6f relay-'89 maybe set to operate prior'to operation of. the delay relay 9B. Inthat event, 1. e.. at? the. end of the rough-polishing interval, operation of delay relay 8% may serve to open the contacts thereof and thereby to break the circuit to the abrasive solenoid 53, thus allowing spring. Eat. to retract the abrasive or wetting drum ll from contact with the polishing means 20. It will be.

clear that polishing will then proceed without abrasive.

. After the lapse of. the selectedperiod'of.polishing without abrasive (finish-polishing interval), the delay relay 99 will operate to open its contacts and thereby to interrupt the circuit to the coil of the double-pole double-throw relay 9i. Relay 911' may then substantially immediately drop out. so as to deenergize the motors |.42l and todeenergize the valve-positioning. solenoid 9A. A. spring 95 associated with the solenoid 94 may return the selector valve 95 to a position calling for retraction of the polishing carriage. Concurrently with the deenergizl'ng of the electricmotors l t-21 and when the relay 9| falls to its: down position, the circuit to thebraking solenoid 61 will again be establishedso that thespindle l'2 may be brought to a halt virtually immediately and with the polishing. means 2.!)- out of contact with the work i l. It will be appreciated that when the polishing carriage 213 is retracted, both limit switches 93-98 will be returned to their normally open condition; in the case of: the switch 98-, the opening of' contacts may deenergize both delay relays 89*90, thus permitting return of the contacts thereof to their normally closed state in readiness: foranotherstart button initiated cycle of operation.

If for some reason during the cycle ofoperation it should be desired to stop mymachine, a depression of the stop button I willv immediately serve to break circuits to the: coils of relays 89 --t.l9i-, and it will'be appreciated. thatv the chest of pushing the stop button may be immediately to shut off the motors: l;4-2 1-, to brake the spindle t2, and to return the polishing oarriage 2o to its retracted position, thereby efi'e'c tively'resetting the. complete: mechanism in readiness. for another cycle of. operation,

It will be appreciated that I have described an improved polishing means having'p'articular application to the precision polishing: of ball raceways for antifriction bearings. By providing selectable delays in the relays. 39-40 I may'control the depthof' cut produced during abrasive-polishing; and during non-abrasive; polishing,v and both. these cuts maybe perl ormcd in quick succession with no'loss of time. My machine lends itself to the simultaneous. polishing and to the uniform polishing; of a: number of sizes and types of bearing rings; and by means of the angular adjustment feature described in connection with securing, bolts 28 and slots 27', the polishing means. 20 may eiiectively finish-polish. a number of differ ent raceway curvatures. In: the particular structure to which I have applied my invention: in the productionpolishing of inner-raceway grooves, I have run the polishing belts 20 at a relati'v'ely slow speed (about 36 R. P. M.) while running the spindle 2 at a relatively high speed (about 7000 R. P. M), depending upon the diameter to be polished. I havev set the delay relay 89 to time the application of abrasive solution for the relatively short period of two seconds. and have set the delay relay 90 to time the finish. or nonabrasive polishing operation torun approximately three seconds: thereafterz. A full. polishing cycle for a plurality of rings may thus be completed in substantially less than 10 seconds, as will be clear.

While I have described my invention in detail for the preferred form shown, it will be understood that modification may be made within the scope of the invention as defined in the appended claims.

I claim:

1. In a polishing machine of the character indicated, a frame, a spindle journalled for rotation on a fixed axis on said frame and including means for revolubly supporting an article to be polished, a slide guided on said frame for sliding movement generally radially of said spindle axis, polishingbelt means carried by said slide and including spaced pulleys on parallel axes substantially parallel to said spindle axis, said pulley axes being differently spaced from the plane of guided movement of said slide so that a belt stretched over said pulleys may present a free span to work supported on said spindle when said slide is advanced toward said spindle, advancing-and-retracting means for actuating said belt means into and out of polishing engagement with the article to be polished, drive means for said spindle and for said polishing-belt means, abrasive-applying means carried by said slide and independently actuable into and out of abrasive-applying relation with said polishing-belt means, and timing means effective while said slide is in a work-engaging position to hold said abrasive-applying means in abrasive-applying position for a first interval and to hold said abrasive-applying means out of abrasive-applying relation with said polishlug-belt means during a second interval, whereby said polishing-belt means may perform both rough-polishing and finish-polishing operations on the work.

2. A polishing machine according to claim 1, in which means including an element to be actuated upon a movement of said advancing-and-retracting means renders said drive means ineffective to rotate said spindle upon a retraction of said slide.

3. A polishing machine according to claim 1, in which braking means for said spindle includes an actuating element poised to interception of said slide upon a retraction of said slide.

4. In a polishing machine of the character indicated, a frame, a spindle journalled on a fixed axis on said frame and including means for revolubly supporting an article to be polished, guide means on said frame and extending generally parallel to said spindle axis. polishing means guided by said guide means and including belt means spanning spaced pulleys, said belt means being sufliciently elevated with respect to said guide means and. said spindle axis that a free length of the belt is poised for polishing contact with the article to be polished, drive means for said spindle and for said polishing means and connected to produce simultaneous relative movements of said polishing means and of the article to be polished at the location of polishing contact, advancing-and-retracting means for actuating said slide to move the free length of said belt means generally radially towards and away from polishing engagement, abrasive-applying means for said polishing means and including a H member actuable independently of said advancing-and-retracting means, disconnecting means for disconnecting said drive means from said spindle, brake means for braking said spindle, and timing means including an element positioned for actuation upon a movement of said advancingand-retracting means to apply said abrasiveapplying means to said polishing means for a first selected timing interval and to retract said abrasive-applying means from said polishing means for a second timin interval and to retract said advancing-and-retracting means upon completion of said second timing interval, said disconnecting means and said brake means bein operative upon conclusion of said second timing interval.

5. A polishing machine according to claim 4, in which said polishing means includes a first plurality of pulleys on a first axis substantially parallel to said spindle axis, and a second plurality of pulleys spaced from said first plurality on an axis parallel to the axis of said first plurality, belt means spanning said pulleys, whereby between each corresponding pair of pulleys on said pulley axes there may be a first free belt span for polishing contact with the article to be polished and a second free belt span, and fluid-pressure preloaded tensioners for each such second belt span, said tensioners being in fluid communication with each other, whereby all belt tensioners may be uniformly preloaded so that a plurality of concurrent polishing operations may be uniformly performed.

6. In a polishing machine of the character indicated, a spindle with means for revolubly supporting an inner bearing ring with a concave race groove to be polished, polishing means including mounting means supporting spaced pulleys on parallel axes that are substantially parallel to the axis of said spindle, and a belt supported by said pulleys for polishing contact of one span thereof with the bearing race groove to be polished, means for moving said mounting means generally radially toward and away from said spindle, abrasive-applying means actuable into and out of abrasive-applying relation with said polishing means, and angular-adjustment means effective between said spindle and said polishing means, whereby the axes of said spindle and of said polishing means may be inclined relatively to each other to produce a polishing contact of said belt with the bearing-race groove at an angle to the radial plane of symmetry of the race groove.

CHARLES G. SCHENK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 605,283 Holland June 7, 1898 675,209 Godfrey May 28, 1901 790,705 Schrader May 23, 1905 1,246,958 Lindsey Nov. 20, 1917 1,475,741 Brown Nov. 27, 1923 1,488,457 Crisp Mar. 25, 1924 1,559,643 Powell Nov. 3, 1925 1,877,572 Harrison et al Sept. 13, 1932 2,119,862 Keller June 7, 1938 2,241,568 Yetter May 13, 1941 2,283,792 Cole May 19, 1942 2,337,776 Scott Dec. 28, 1943 2,341,442 Hulbert et al Feb. 8, 1944 2,386,850 Gaudreau et al Oct. 16, 1945 2,445,391 Elmes et al. July 20, 1948 2,479,536 Elmes Aug. 16, 1949 2,489,811 Perkins Nov. 29, 1949

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