US2761255A - Polishing machine - Google Patents

Description

Sept. 1956 IEPACKOR 2,761,255

POLISHiNG MACHINE Filed 001,. 2, 1953 8 Sheets-Sheet 4 21/ f2? Vania?" .FM/L LDACKOE:

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Sept. 4, 1956 E. DACKOR POLISHING MACHINE 8 Sheets-Sheet 5 Filed Oct. 2, 1953 [Hz En [27F ZM/L DA 0260B Sept. 4, 1956 a DACKOR POLISHING mums 8 Sheets-Sheet 6 Filed Oct. 2 1953 km. m 9mm MQQ Sept. 4, 1956 E. DACKOR 2,761,255

' POLISHING MACHINE Filed Oct. z, 1953 a Sheets-Sheet a F fi b m H fi n A w E D 3N V. u n M u. fr H. 4 Q a w l M l w w Mn. NR. 7 l A NE maw w Illl III I J m; m Ex p I swwmw if K m3 M ow 8 MG v \w% 3w NW w N v w MN MNMN w m an R6 u. I? Sm. WWW l a owh m @NE pieces.

.a multiplicity of workpi'e ces simultaneously mounted on a turret-type rotary mechanism.

,toprovigle a new and improvedtturret typepolishing .chine wherein a number of workpieces ,suchas t bine 2,761,255 POLISHING MAcuiNr;

Emil 'Daclror, Euclid, Ohio, assignor to Thompson Products,:Inc., Cleveland, Ohio, aIcorporation .of Ohio Application Octoher 2, 1953, Serial No, 3 83,8519 12 Claims. (81 51-151) The present invention relates to a polishing machine.

and more particularly relates to a machine Operable to eiiiciently, economically and rapidly polish a workpiece such as a turbine 'blade or bucket or vane or the likehaving oppositely disposed complex arcua te surfaces which may be of airfoil configuration or the like.

plurality of polishing units are mounted on a rotatable turret and each carries a separate workpiece for simultaneously polishing the surfaces of a plurality of work- At an operator station which is a preselected position about the rotatable turret, a finished and polished workpiece is ejected or released :f rom each successive polishing unit and a new workpiece to bepolished inserted into, each successive unit for polishing.

A Before the system of the above-mentioned patent was developed, polishing of such complex arcuate sur faceson oppositely disposed faces of a workpiece suchas tufbine blades, buckets or vanes was effected by ha lidl olishi ng "methods which necessarily involved long and tedious arid.

@XPfinsive working and provided no assurance of-iiniforrnity of the finished workpieces. The system the aforementioned patent resolved that V c vided a machine readily operable to economically polish i ue td ity of poli machinealso included a plural tern of the present invention, however, provides (an .1

e re is i st n e h n sm e e t e sys e 59 th ehsve-ms e Pat n It there fore, an important feature of the present-inentiq to pr v d a ne n imPmWdpd h n mai ings- Y it, ,is another important feature of the present invention ta hes of n 9 blade ha i ns t rtiuss r tqmnle ar s s a e m be reli h -susta n ewnomically and simultaneously.

-Another ,object and feature of the,presen t inver tion is .to provide a polishing system ,for a-workpiecesuch asga turbine blade wherein the workpiece oscillated between aupair. of relatively stationarypolishis reciprocatedtand ing members by a workpiece holding memben andcoperating device. I

Still another object of the present invention is to provide a polishing mechanism of the horigontally rotatable turret-type wherein a number of polishing units are carried one turrettype drive mechanism and carrying ne'ch- States Patent reeling mechanism and polishing Patented Sept. 4, 1956 anism and wherein the drive mechanism and carrying mechanism is new andimproved.

improved power take oIf system.

Still another object of the present invention is to provide a system of the class described wherein each polishing unit is provided with a pair of polishing belts each trained over a polishing pressure pad carriedby an improved pad-carrying mechanism.

Still another object of the present invention is to provide each of the polishing units with a new and improved pad operator mechanism and a new and improved work clamping jaw operator mechanism.

Still another object of the present invention is to provideeach of the polishing units with an improved independent jaw-operating mechanism and independent p a d operator mechanism. li l A still further object of the presentinvention is to provide each of the polishing units with a shock mounting operator system for [each of the pa dfcarrying mechanisms. l i A still further object of the present inventionis 10 provide each ofthe polishing units withadiniproved polishinghelt reeling mechanism.

" Yet another object of the present invention is to pro- 1 i PE PI WS vide each ofthe polishing units with a raw rele e m sha m A still f nrther object of the present invention is to provide a new and improved polishing helt lockin g mechanism Still another object of the video. now and improved P e ent wsnfien i torred s r n operat n rnechanism for both reciprocatingdand oscillating tlie workpiece.

Still another object of the present invention is to provide a new and improved cam and follower system for opei'atinga polishing machine of the class described in a new and improved manner. V I

.Still other objects, features and advantages of the present invention will readily present themselves .totho se skilled in the art from the foregoing andltfrom the following detailed description and from the accompanying sheets ,of drawings illustrating a preferred embodiment of the present invention and forming an integral pa rt of this Specification, in whichlike referencetnumerals,refer to like parts, and in which: q i

Figure 1 is a top plan View, partially in diagrammatic illustration, illustrating a preferred emnqdnnent of the present invention;

Figure 2 is apartial sectional view of the system of Figure 1 is taken along the line I I--II of Figure I Figure Bis a side elevational view of a single polishing unit embodying the principles of the present invention as viewed along the line lIIf-lll of Figure 1 Figure 4 is a front elevational viewofa single polishing unit embodyingnthe principles of the present inventiongas viewed along the line IV- -IV of Figure 1;

Figure 5 is a top plan view, partially in section, of the cam and cam follower system and polishinggpad. carrying and operatormechanism as viewed along the line "V -V of Figure 3;

Eigure 6 is an enlarged front elevationaltview of the pad operator mechanismtaken'along the line VlI-VI of Figure 3;

Figure 7 is an enlarged front elevational view of the work-carrying ram and jaw and oscillator mechanism taken along the line VII-VII of Figure-3;

Figure 8 is a sectionalview of aportion of the .jaw release mechanism taken along the line .VIII*VIII of Figure Figure 9 is a bottom plan view of the jaw mechanism and workpiece holder oscillating mechanism of this embodiment of the present invention taken along the line IX-IX of Figure 7.

There is illustrated in Figure 1, partially in diagrammatic illustration, a top plan View of a machine, indicated generally at l, embodying the principles of the present invention. The machine 1 is preferably a turrettype machine carrying a number of polishing units 2a, 2b, 2c, 2d and 2e. The number of these units on the machine 1 is not critical and may be as large a number as desired. The machine 1 of the present invention has been i1- lustrated with five such units generally identified by the numeral 2, mounted on a pentagonal turret head 3 for substantially horizontal rotation about the center of the machine. The rotating head or turret table 3, of course, need not necessarily be pentagonal but it is preferred that the turret table 3 have a regular configuration which may be round or have any number of sides preferably corresponding to the number of polishing units such as the units 2a, 2b, 2c, 2d and 2e supported thereon and rotated thereby about the center of the polishing machine.

The turret mechanism 3 includes a turret table-type device 301 which is carried by a supporting unit 302 to rotate the polishing units about the center of the machine and over a preferably substantially circular coolant tank 4. The coolant tank 41, as illustrated, has a bottom wall 401 with an outside diameter suflicient to extend substantially to the radial extremity of the units 2 and there has an upturned flange or peripheral side wall 402. The tank structure 4 may, of course, have any desired configuration and construction but the above is preferred when employing a coolant with the system of this invention.

The turret mechanism 3 including the turret table structure 3M and the supporting structure 302 may be best understood by reference to Figure 2. As shown in this figure, the polishing unit 2a, along with the other polishing units which are not shown in this figure of the drawings, is supported by the side plate 3% of the rotary section 301 of the turret to which it is secured by any convenient means such as bolts or screws or studs 304. Stand-off spacers 3%, which may be washers or the like, properly space the polishing units, such as the unit Zn, from the side walls of the rotary section Etll of the turret mechanism 3. Individual polishing unit drive motors 2% are secured through base plates or the like 202 to a turret table plate 3% by means of bolts or the like 397. The turret table plate 3% forms the upper face of the rotating section 331 of the turret mechanism 3 and is secured to the side walls 3% by any convenient means such as welding or bolting or riveting or the like, and in this preferred embodiment of the present invention, as illustrated in Figure 2, is secured to the side walls 303 and supported thereon through angle iron members or the like. The rotary turret table section 3% is also provided with a bottom plate 363'? which is secured to the side wall members 3% in a like manner to the manner of securing the table plate 3% to the side walls 393.

In the geometric center of the turret assembly 3 and particularly through the rotary turret section 3631, a space bounded by internal walls 3tl9 is provided for a supporting column 314) which extends from the lower extremity of the base section 302 to the very top of the machine. This column 310 is preferably a hollow one and carries, through the interior thereof, numerous of the electrical power leads and control leads for the mechanism and sys tem of the present invention. in addition, thrust-type roller bearing assemblies 311 and 312 are secured to the column 310 and the upper and lower turret table plates 306 and 308. The thrust bearing assemblies 311 and 312 are preferably roller-type bearings, as illustrated, but: may be any other desired type of thrust bearing, and while they are preferably securely fixed to the upper and lower turret table plates 3% and 308 by machine screws or th like 313, the inner races of the thrust bearings are adjustably secured to the hollow supporting column 310 in any convenient manner such as by positioning nuts or the like 314 threadably engaging the supporting column 310 and positioning the bearing assemblies 311 and 312.

The pedestal or base section 3&2 of the turret assembly includes an appropriate support 320 at the lower extremity thereof for the hollow supporting column 310. The pedestal or base section 302 also houses the rotary power mechanism for rotating the turret assembly about the center of the machine, about the supporting column 310 on the thrust bearings 311 and 312. The rotary power mechanism itself includes a convenient driving machine such as an electric motor 32ft which is fixedly secured by a mounting base member or the like 322 to a cross frame 323 secured at its opposite ends to the side wall 324 which is reinforced by appropriate members 325.

Above the turret rotating drive motor 321 the supporting bracket 323 carries a journal assembly are housing a worm gear or the like 327 and a pinion shaft 328 mounted in appropriate bearings 329. in the region of its lower end, the pinion shaft 328 has an appropriate gear 339 secured thereto to mesh with the worm gear 327. The motor 321 and the worm 327 each carry sprocket wheels 331 and 332, respectively, which are appropriately interconnected by a sprocket chain 333. Rotational power produced at the motor 321, which is preferably an electric motor, imparts rotary motion to the worm gear 327 which in turn drives the gear 33d and the pinion shaft 328. At its upper end the pinion shaft 328 carries a pinion gear which mates with a rim gear 335 or the like. This rim gear is securely fastened to the lower turret plate 3% by any convenient means such as a bolt or machine screw or the like 336 and is concentric with the supporting shaft Bill. Thus, rotatably driving the pinion shaft 325 rotates the pinion gear 334' and thereby drives the gear and the rotary turret head 301, the rotary turret head rotating about the supporting column 3ft on bearings 311 and 312.

Additional supporting structure is provided within the pedestal 302 by a structural plate member 337 which is secured peripherally within the pedestal or base 392 and to the side wall structure 324 thereof carrying a bearing block 338 which supports the column 310 against distortion from the weight load thereon in compression. The structural plate 337 also carries an additional supporting element 339 which operates to support and position tl 1 e journal housing 326 and thereby the pinion shaft 328.

In addition, the hollow supporting column 310, at its upper end, carries an electrical power take-off system 350 for selectively providing electrical power to the motors 201 of the polishing units 2. In high power electrical applications it is preferred to use three phase electric power brought into the system on three leads, not shown. Each of these leads would be brought through the hollow interior of the supporting column 310 and one aiiixed, electrically, to each slip ring or electrical power take-up ring 351, 352 and 353, which are otherwise insulated by ring insulator members 354- from the remainder of the system. A set of three brushes 355, 356 and 357 are supported on a contact-carrying post 353 which is secured to the upper turret table plate 306. The brushes 355, 356 and 357 are, of course, insulated from the carrying post 358.

Since each of the polishing units indicated generally by the numeral 2, is substantially identical to each of the other polishing units, it is necessary to describe only one of the same in detail. The polishing unit 2a will, therefore, be described in detail and this unit 2a is best viewed in full in Figures 3 and 4 of the drawings. As stated hereinabove, Figure 3 is a side elevational view of a single complete polishing unit, the unit 2a, and Figure 4 is a substantially full front elevational view of the same polish ing unit, the unit 2a.

The principal operating portions of the polishing unit r211 are .carried .by a

.- section for. the polishing unit ,pair of pulleys t2ti8and output shaft 210 of :the'motor ztl predominantly in a one indicated generally at 413. .;,-portions 414.facially engage preferably-arerticallytmounted.i-fram or stand 203 which: is secured to :the-iurret .wau 303 .by .the bolts or screws/or studs 304. and spaced v.therefrom .by the .washersorthedike 3,95,;as described above. vAn tupper padmember 204 supports a powendrivenram reciprocating mechanism indicated generally at 4, while a .lower pad member 205, on the mainrframe 1support203 .carries the work holding andram mechanism-indicated ,generally at.5. Aramoscillating mechanism, vindicated generallyat .6, is secured to the upstanding: frame and s upport.2tl3 .below the mower-driven ram reciprocating .system 4 and. laterally immediately adjacenttto the work- ;.holding-mechanism .5 and :the pad member -205.

.In. addition, the PPOrtvmember 203 has .a lower-out- ,wardlytextending flange v12.06 which:operably supports, a ijawn'elease or .work .holder release. operator mechanism 7, .apolishing surface padmember carrying-mechanism 8 .vanda pad member retracting operator zmechanism19.

.A bracer and support membert207 (Eigure 4)- is secured fitothe forward faceofthe upper pad member'204 and .carries .a housing 401-,fr the power-driven reeiproeator 2a. A ,shaft -402 is .journaled in .the housing 401 and in the region of oneend thereof-has a plurality ofpulleys/103, .404 and 405 keyed thereon for rotation therewith, the rotating force to ;be

utransmitted to the shaft 402by the pulleys 404- and. 405.

.Each of the pulleys 404 same diameter and are and .405 are of substantiallythe coupled by belts or the like .406 and .407 to another pair of pulleys 208: and 209twhich-are to bedriven by the polishing unitmotor201. Thislatter 209 v are preferably coupled to the At theother endof the shaft z402-a.crankdisc 408 is keyed. or "otherwise secured sthereto fortrotationrthereguideway409 and is longitudinally bored and threaded for locking acceptance I of t the threaded end i 412 r of a. spindle A pair of separated shoulder opposite sides of the retainer and-spacer block 415 in the region of the head 416 of the spindle413. The spacer and retainer block 415:isi fixedly ,secured in any convenient -way409 nearest the center of the crank:disc 408. The

manner to theend of the crank head end 416 of the crank spindlez4l3 is properly proporationed for manipulation by an. appropriate tool for con- -venient rotation of the crank spindle413and thereby convenient increasing and/ or decreasing of the spacing ofthe cross head 411 fromthe ,centero'f the crank disc 408 along ethe track channel 410 ofthe crank way 409.

.A connecting rod 420 has one of its ends journaled on the'tcross head assembly 411 and retained thereon by a retainer screw such as a machine screw 421 having an enlarged head section orwasher 422at the hea d to retain the connecting rod 420journaled onto an appropriately .configurated portion of the cross head assembly 411. At its other end the elongated connecting rod 420 is journaled onto an appropriately configurated section of a-second :cross head 430 and retained thereon by a similarly appropriate retainerscrew 431 and washer orthe like 432. This second cross head assembly 430 is provided with 'an' end plate 433 secured to the opposite end thereof from the connecting rod 420 by any convenient means such as 'another machine screw or the like 434 and is thereby constructed to track in an elongated opening 501 in the upper portion of the front face of the work-holding assembly 5. A second spindle rod 502 threadedly engages the cross "head 430 andis also provided with shoulder portions 5'03 ;at;its head end 504 to facially engage a retainer plate 505 1411, etc. and-thatthese two assemblies "work holder support about the axis of the secured .onto'th uppe e d of the wo k-ho dingearria assembly 5 immediatelyover the openingfill.

lttwill be appreciated that this preferred ernbodiment of the present-invention the upper end of the work hol ding assembly ,Sincluding the opening 51and therassooiated crosshead 439 and spindle member-.502, etc. closely ,resemble the crank-way 499 and its associatedcross head a e i t rconne te a pp ey ae and a lowerv ey e end by the connecting rod 420 having 'journaled on the cross head 411 journaled on the cross head 430. Through operationw of thismechanism as the shaft 402 is rotated by thepolishing unit motor 201 the work-holding assembly ;5 ;is reciprocated, the amount of reciprocation, thatis theiam- 'plitude of the reciprocation, is controlled ,by the position of the cross head 411 with respect tothe-centenpfrthe crank disc 4%. This amplitude of reciprocationv is-tadjustably controlled by the spindle .4113. The vertical positioning of the work-holding assembly 5 may be adjusted also in a similar manner by rotatable manipulation ofrthe spindle 502, the head end 504of which is also properly .coniigurated for acceptance of an appropriate :tool.

The work-holding, clamping and release mechanism: 5 which is in-part reciprocated by the mechanismA immediately above described, is supported from the ;pad 205 for pivotal movement with respect thereto (Figures3 and 9.). A work holder track assembly 510 has a; main track {bed member fillprovided with a pair. of rearwardly extending ears 512 and 513 orthe like which arejournaled :ona pivot shaft or pin 516WhiChlS mounted through a -recess;212in the pad blockZllS. The recess 212 extends less thanthefull distance between opposite sidesof :the block 205 thereby leaving pivot ears 213 and 2-14 thereon for acceptanceof the pivot shaft 516. Sleeve members .215 and 2.16 are fitted into appropriate openings in the ears 213and 214 and surround the shaft "516. Thcshaft 5ll6 itselfmay be either secured1to the'pad 205 ,with the release mechanism journaled "thereon or. secured to .the track assembly andijournaled in :the; pad block ears 213 and 214thus permitting pivotaLmovement of the work holder mechanism 5 with respect to the frame pivot shaft 516 without opportunityfor the shaft 516 to become displaced.

This pivotal arrangement for the work holder:mecha nism 5 is provided to permit oscillation of the unit byrthe oscillator mechanism 6 as described indetailbelow. Before examining the oscillator mechanism 6, however, detailed. discussion of the workholder mechanism 5 will be substantially completed, atleast with respect to the reciprocator mechanism 4.

The work holder track assembly 510 which is pivotally =supported onthe pivot shaft or pin 516 is principally constructed fromtthe main track member 511. The main track member 51-1 is substantially channel-shaped'having a central longitudinally extending channel 520 therein bounded on three sides by inner faces of 'themain track element 511. Buffer plates 521 and 522 are secured to the extreme front face of the main track element Sllatid project a short distance laterally over the channel5 20 thus providing a positive track channel in the track assembly 516). Bearing plates 52.3, 524, 525 and 526, which may be constructed of oilless bronzeare secured to the main track member 511 and form a major portion of the raceway therein. The work-holding, clamping and release mechanism 5 also includes the work carriageindb cated generally at 530. This carriageaSSEI istprovided with a housing 531 having a flanged backface, including 1 the 1 laterally extending flanges 532 and 533 which, track within the track-bed assembly 510 and are. reciprocable within the track bed as operated upon by the reciprocator mechanism 4.

As previously pointed out, the reciprocator=mechanisjn -4 acts upon this carriagemechanism 530'th1ough thezsystern above described v to reciprocate the carIiage SSOrmcluding the flanged housing 531 substantially vertically in the track assembly 510 therefor.

Also as stated, the work-holding assembly is pivotally mounted to the frame pad 205 for oscillatory movement of the work holder in conjunction with and in cooperation with reciprocatory movement thereof. This oscillatory movement is provided to the work holder by an oscillator mechanism 6 which is best viewed in Figures 3, 4, 7 and 9. The readers attention, however, is principally directed to Figures 7 and 9 for the best understanding of the oscillator mechanism 6.

A small pulley 463 (Figure 4) which is keyed to the shaft 402 drives a belt or the like 601 which in turn drives an oscillator mechanism drive pulley 662 keyed to an oscillator mechanism shaft 653. The oscillator mechanism shaft 603 is journaled in a journal housing 694- which is secured to a mounting bracket 605 that is adjustably mounted and secured to the main frame stand 263 preferably on a $113.11 pad 218 by any convenient securing means such as machine screws or bolts 666.

Within the journal housing 696 a pair of bearing members 607 of appropriate qualities such as frictionless bearings of the ball type or roller type are secured in place and rotatably support the oscillator mechanism shaft 603. The inner race 6% of one of the bearings 667 is seated against a shoulder portion 669 on the shaft 603 and held in place by a nut 610 threaded onto a small threaded section 611 of the shaft 663 having a smaller diameter than the principal remaining section of the shaft 603. At the other end of the shaft 663 it is still further enlarged and threaded to provide for seating of the inner race of the second bearing 697 and securing of the same to the shaft 603 by an appropriate nut 612. The end of the shaft 603 opposite to the end where the pulley 662 is keyed thereto is still further enlarged as at 613, or if it is found convenient an enlarging member such as the portion 613 may be secured to that end of the shaft 663, and outwardly therefrom there is carried a slightly eccentric portion 614 which may be either an eccentrically machined portion of the shaft 603 or a roller carried and journaled on an eccentrically machined portion of the shaft 663 or a roller carried on an eccentrically machined portion of the enlarging member 613 secured to the shaft 603 as desired or found convenient. In any event, the shaft 603 is provided at one end thereof, the end opposite to the pulley 662, with an eccentric member 614. The eccentricity of the member 614 need not be great and in a preferred embodiment of the present invention the eccentricity may be about @1 of an inch more or less as found convenient. The important feature is that this slight eccentricity provides oscillatory movement to the workpiece to prevent surface polishing along a single path thereon, thus avoiding channeling or grooving due to grit or dirt or the like which may be present on the surfaces of the polishing belt. This subject matter will be further discussed in detail below.

An oscillator block 535 is secured to the side of the main track bed block 511 of the work holder assembly 5 immediately adjacent to the oscillator mechanism 6. This oscillator block 535 is provided with a channel 535 therethrough having a width about the same, or very slightly greater than the diameter of the eccentric roller or the like 614. The eccentric member 61% seats within the channel 535 and upon powered rotation of the shaft 603 horizontally oscillates the work holder assembly and mechanism 5 thereby pivoting the same about the pivot shaft 516. Vertical eccentricity of the member 614 is lost within the channel 535'.

From the above it will be understood that upon energizati'on of the motor 201 and the magnetic clutch or the like 211, if the same is provided to the shaft 216 of the motor 201, the work holder mechanism carriage 530 will be reciprocated by the reciprocator mechanism 4 and the whole work holder assembly 5 will be oscillated by the oscillator mechanism 6 about the pivot pin or shaft 516.

The work holder carriage housing 531 is a substantially hollow member within which it carries a jaw mechanism as best viewed in detail in Figure 7.

A workpiece 10 such as a turbine blade or bucket or vane having a fluid guiding blade section 11 and a base 12 is held between a pair of arms or jaws 536 and 537 having jaw inserts 538 and 539, respectively. These jaws or arms 536 and 537 are journalcd on bearings or the like 540 and 641, respectively, for clamping or releasing rotation of the jaws toward and away from each other at their jaw insert ends. The bearings 54th and 541 need be no more than pivot pins provided in a chuck bracket 542 at its lower extremity. The chuck bracket 542 includes a sleeve section 543 above the jaws 536 and 537 and is there journaled in bearings 544 and 545 the outer races of which are seated against the inner wall of the carriage housing 531 for rotatable mounting of the workpiece clamping jaws. The bearings 544 and 545 are firmly positioned by a bearing spacer 546 positioned therebetween, a bearing retainer ring 547 secured to the lower extremity of the carriage housing 531 and a sleeve member 548 threaded onto the upper end of chuck sleeve 543. A shoulder 549 of the chuck sleeve 543 rests against the lower side of the inner race of the bearings 544 also assisting in holding the bearings in proper position.

A pin or rod 550 is slidably fitted through the chuck sleeve 543 so that a lower tapered end 551 thereof is engageable with arcuate upper ends 552 and 553 of the jaw members 536 and 537, respectively, in camming relation. Immediately above the upper end of the chuck sleeve 543 the pin or rod 550 is provided with a shoulder 554 against which a washer or the like 555 rests. A compression spring or like biasing member 556 rests on the washer 555 and is retained in position about the rod 550 by a spring retaining cup 557 slipped over the upper end of the rod 550 and threaded onto the sleeve 548.

The spring 556 is thus operably disposed to continuously bias the pin or rod 556 in the direction of the jaw members 536 and 537 so that the tapered lower end 551 of the rod 550 is continuously biased against the camming upper ends 552 and 553 of the jaw members thereby biasing the jaw members 536 and 537 into a closed clamping locking relation with the base 12 of the workpiece 10. Raising of the pin 556 through operation of the jaw release operator mechanism 7 operates to release the workpiece 10 from the jaw members 536 and 537 which are biased apart by a spring member or the like 558 seated in small recesses 559 and 56th in the jaw members 536 and 537 intermediately between the jaw inserts 538 and 539 and the pivot pins 546 and 541.

The worloholding mechanism and assembly 5, specifically, and the whole turret-type polishing machine 1, generally, is equipped with a jaw-release mechanism 7 for each of the polishing units. The jaw-release mechansrn 7 for the polishing unit 2a is best illustrated, and may be best understood, in conjunction with Figures 3, 5, 7, 8 and 9. Before undertaking an understanding of the whole jaw-release mechanism and operator mechanism 7, how ever, the reader should first understand the operation of the portion of the jaw-release mechanism which forms a part of the work-holding carriage 530. This portion of the jaw-release mechanism is best viewed in Figures 7, 8 and 9.

A small journal box 56111 is secured to the outer face of the carriage housing 531 and therein carries a jawrelease mechanism shaft 561 journaled in bearings 562 so that the shaft is disposed forwardly of the carriage housing 531 and transversely thereof. At one side of the carriage housing 531 and at one end of the shaft 561 a crank handle extending upwardly and rearwardly in the jaw-lock position is pinned or otherwise fixedly secured to the shaft 561 for positive rotation of the shaft with the crank handle 563. As illustrated in Figure 8 the crank handle 563 fits onto one end of the shaft 561 and is pinned into positive engagement therewith by a pin member 564.

Intermediate the ends of ithe shaft 561 a leveror the .like

5,65is-keyed onto the shaft- 61-for positive rotationtherewith. This lever'.565 has.a bifurcated endportion including arms 566 and 567 which extend around the rod or pin 550 that ,cammingly serves to openor closethe jaws 536 and 537 of the workvholding mechanism. At the upper end of the rod 550rod-raisingnutmembers 568 threadably engage the rod or pin 550 immediately above the area of therod where the arms 566 and 567 of the bifurcated end portion of the lever 565 surround the rod. Thus, it may be seen that rotation of the shaft 561 by manipulation .of the lever handle or crank handle 563 operates to push the ,rod upwardly thereby permitting opening ofthe jaws under the biasing force of the spring .558, thereby releasing and/or ejecting the workpiece 10. 'Renotationvof the shaft561 returning the crank handle '563to its normal position, returns the camming lever 565 toits normal position permitting closure and locking of thejaws 536 and537by action of the biasing spring 556 urgingfthe rod orpin550 downwardly against the arcuate cam endsl52 and 553 of the jaws 536 and 537.

In accordance with the principles of the present invention, the polishing machine 1 is equipped to .release the workpiece held by each of the polishingunits 2a, 2b, 2c,

"2d and"2e as each approaches an operator station which is a preselected position about the general periphery of the machine 1. A preferred embodimentof this mechanismfor automatically releasing or .ejectingthe workpiece isillustrated in conjunction with thepolishing unit 2a in Figures 1, 3 and Sand is indicated generally by the numeral7. A portion of .the workpiece release operator mechanism "7 is duplicated on each ofthe polishing .units of the machine 1 and another portion thereof is secured to the pedestal or base portion 302 of the turret mechanism 3. Specifically, and as shown on the drawings, a workpiece release operator cam '701 is secured to the outer peripheral wall of the pedestal section 302 near the top thereof and in-the vicinity of the operator station in any convenient manner such as by bolts or'screws or the like afiixing the same to an "angle ironsupport orthe like 702. The cam 701 is so contoured as to have maximum radial extension in the vicinity of its leading edge 703 as it isapproached by each polishing unit. Thereafter, for a short distance the cam 701 has a substantially constant radial extension as inithe area 7.04 thereof after which the radialidimension diminishes a preselected amount for a substantially greater arcllength as in the area 705 until the trailing edge offthe cam701'in the vicinity of the end of the operator station. This cam construction may be best observed in Figure 5 in elevation and in Figure 1 in invisible linejillustration.

.By this construction the cam 701 is provided with a .camrningface 706 which controls the operation of the work-release operator mechanism 7. The cam face706 is engagedby a roller'707 which is journaledbetween the armsof a first bifurcated end portion 708 of a substantially centrally journaledlever -709. The lever '709.has

an oifset H shape as edge viewed (Figure 3) and the roller707 is journale'd on a pin or the'like 710 between the arms 711 and712of the end'708thereof. A control supporting post 713 is secured to the flange 206 of the support bracket 203 and oarriesthe lever 709 in a journaled manner thereon.

The other bifurcated end 714 of a second arm of the lever 709 pivota'lly carries a link'715 which is coupled to a second substantially H-shaped lever 720through a universal coupling unit 716.

This second substantially H-shaped lever '720 is centrally journaled on a pin. or shaft or the like721 on the main track member 511 for substantially vertical plane pivotal movement. The universal coupling linkage 716 interconnects "the lower bifurcated arm 722 of the lever "720 and the arm714of thelever 709 such that horizontal "plane pivotal movement of'the lever '709 on the post713 imparts vertical 'planepivotal movement tothe lever 720.

Theiupper bifurcated arm 7239f the lever 7..20,is ,pivorally pinned as at'72.4.to a workyr'elease, operator baf .725. Inthe region of its opposite endfromits connection ,with the lever720, the-Work-release operatorbarilZS ,,is,;pivotallypinned as at726 to :anotherlever727 Which-is also journaled or pinned to themain track memhersllfisat 728 for substantially vertical plane pivotal movement.

The levers 720 and 727 cooperateto supportthe release actuator bar 725 substantially vertically subhthat,a,leading face 730 thereof, the frontedgeof the bar"725,,.1ics in a substantially vertical line and in plane movement relation with a roller or the like 731 ,j-ournaled ,in fthe free end ofthe work-release, actuator handlefor. craiik563. This work-release operator mechanism (FigurejS) 'islso operative that engagement of the roller with the camjface 706 in the region704 of the cam'701 pivots the lever-"709 about the post 713 thereby pulling thelower end722 of the lever 720 (Figure"3) rearwardly pivoting thesame about the pivot 721 and moving the upper Varm723 of the lever720 forwardly and'downwardly. 'Thefllever7'27 follows the movement o'fthe upper arm 723 of the lever 720 throughits positivelinkage therewith via the'bar'725 ing and ejectingihc workpiece 10. Asthe roller'707 rides the camming face'ififi ofthe'cam701 in the region'704 thereof the jaws 536 and 537 are opened to amaximum spacing therebetween thereby permitting theworkpiece 10 to fall freely therefrom. "The radial dimension "of the region704 may, of course, be so controlledth'at'the workpiece '10 will merely be released but will not'fall orbe ejected by virtue of insufficient opening of the jaws'5*36 and 537 to permit such ejection. In this preferred embodiment of the present invention, however,thejaws536 .ancl537 are opened'to eject the workpiecelO when the roller 707 rides the cam in the region704 thereof.

As the polishing unit mechanism 2a continues, iniits movement about the maohine las dr'iven'ibythe-turret mechanism 3, the roller 707 leaves'the region 704 ofthe cam 701 and moves intothe region705 oflesser-radial extensionthereby slightly retracting the release op'erator bar725 and in turn slight retracting the-releaseope'rator handle or crank563 to movethejaws536 and 537slightly closer together. L In this regionof operation-the jaws '536 and 537 are separatedby a distance sufiicienttqperniit free insertionor removal of a-newworkpiece 10. The spacingbetween the jaws'hereis notsufiicientto permit dropping or ejection of the workpiece-10 but "is small enough to support the workpieceltl.

Continued movement 'of thepolishing unit mechanism 2a past the trailing edge of the cam ,701 and out of -the operator station releasesithe release-operator mechanism from the cam 701 therebyretracting the release operator bar 725 completely from the release handle or crank563 thereby permittingthe pin 550to cammingly wedge between the'upper'ends 'of the jaws 536 and 53'7-thus-clamping the workpiece 10 between thejaws. The barlZS is retracted under a biasing force providedby any convenient means such astabiasingtension spring 7'40ihookedto the 'maintrack member 51 1 at one end and tothe' bar725 at its other end.

ative in accordance with the principlesthereof isillustrated in and may be best understood in conjunction with Figures 3, 4, and 6. The lower portion of Figure 3 illustrates the polishing surface mechanism 8 in side view, while the lower portion of Figure 4 illustrates the same in front view and Figure 5 is a top elevational view of a portion thereof. Figure 6 is an enlarged front elevational view of a portion of this mechanism.

The polishing surface mechanism 8 includes a pair of retractable, pivotally mounted, polishing head and reel mechanisms 801 and 802 which are substantially identical to each other and symmetrically arranged to each present a polishing surface to the workpiece 10. A carriage plate 803 secured to the flange portion 2% of the main support bracket 203 and extends substantially across the entire width of the polishing unit 211 supporting the several parts and elements of each of the haivcs 3H and 892 of the polishing surface mechanism 3.

The polishing surface provided on each of the mechanism sections 801 and 802 is provided by training a polishing belt, such as the belts 8M and 805 which may be sandpaper or sanding cloth or emery cloth or the like, over a polishing pad 306 and $67, respectively. The polishing pads 8% and (W7 are preferably constructed from a resilient material such as a rubber-like material and are mounted on pad brackets 8M and 8G9, respectively, for pivotal movement toward and away from each other and the workpiece it). For accomplishment of this pivotal movement the pad brackets 808 and W9 have pivot ears or eyelets 810 and 811, respectively, at their lower ends whereat they are journaled on a pin or shaft 812 which is positioned in line with the workpiece iii and workholding mechanism 5 and secured to the polishing system carriage plate 893.

Since each of the polishing sections 801 and 86 2. are substantially identical in construction and symmetrically assembled, a description of one of the same, tiull, will operate to describe both thereof. For simplicity of ex planation and understanding only the polishing rnechanism section 301 will be referred to for the following detail assembly description.

As stated, the pad bracket ens carries the polishing pad 8% over which the polishing surface belt 3% is trained. The pad bracket 398 also carries a belt clamp 813 including a stationary lower jaw 614 and a retractable jaw 815. The retractable jaw 815 is formed as a bent lever-like construction pivoted substantially centrally on a pin 816 held in the upper reaches of the pad bracket 868. The end of the clamping lever 315 opposite to the actual clamping jaw end thereof carries a cam roller 817 journaled thereon to rollingly engage a polishing belt clamp-release cam surface 813 on a cam block 819 affixed in its position on the supporting structure. Biasing means such as the compression spring 820 biases the pivoted jaw arm into clamping relation over the lower jaw 814 and further biases the cam roller 817 into engagement with the cumming surface $18 of the cam block 819.

The belt-clamping and cam arrangement is so constructed that when the polishing pad bracket 8% is retracted to the position seen therefor in Figure 6, the jaws are separated from each other and from the polishing belt 804 through action of the roller 81! riding on the camming surface 818. With the polishing pad bracket urging the belt 804 into polishing engagement with the workpiece It), the polishing belt clamping mechanism 313 is substantially released from the cam block 819 permitting the spring or the like 820 to urge the jaws of the clamp into clamping relation. This latter position is seen in the general front assembly view of Figure 4.

The polishing belt 804 is supplied from a supply reel or the like 830 positioned over the cam block 819 and supported for unreeling rotation on a reel bracket 3311 at w an upper eye therein as at 832. In the assembly at the upper eye 832 of the reel-supporting bracket 831 the reel 830 is journaled for rotation and provided with a 12 friction dragging brake assembly 833 adjustably controlling the drag on the reel 830 when the belt 804 is pulled therefrom through operation of the hereinafter described automatic belt polishing surface feed mechanism.

A take-up reel 834 is journaled in the carriage plate 8% somewhat below the supply reel 830 and behind the pad carriage bracket 893. The reel 834 is also supplied with a hub braking mechanism 835 which is adjustably controlled and prevents free rotation of the take-up reel 834.

The polishing belt 804 is supplied from the supply reel 33% with its polishing surface facing outwardly and is successively trained over a positioning roller 84f) journaled on a small bracket or the like $41 immediately behind the polishing pad and belt-clamping jaws, between the beltclamping jaws are and 815, over the polishing pad 806 which is resiliently urged outwardly, over a second positioning roller $42 journaled on the bracket 8'38 adjacent one of the pivot ears 8X6 between a pair of feed driving rollers 843 and 344 with the roller 844 controllably rotated by the belt feed mechanism and the roller 843 urging the belt 8% into close engagement with the roller 8% so that rotation of the roller 844 will operate to move the belt 804 longitudinally, and about the hub of the take-up reel 834.

Each of the polishing units, such as the unit 2a, is equipped with an automatic polishing pad and polishing surface retraction mechanism and polishing belt feed mechanism 9 which is operable to retract the polishing pads and pad mounting brackets and to feed a preselected increment of the polishing belt forwardly thereby releasing the workpiece from the polishing unit mechanism 8 and providing a new polishing surface on the belt over the polishing pad at the operator station and at other preselected positions about the periphery of this turret-type polishing machine 1. The pad-retractor and belt-feeding mechanism 9 is somewhat similar to the automatic workpiece release mechanism '7 in that it is provided with a cam 9M, Figures 3 and S, secured to the pedestal section 392 of the turret support and extending peripherally thereabout as seen in invisible line plan View in Figure l. The outer peripheral surface 962 of the earn 981 is the camming surface controlling the operation of the retracting and belt feed mechanism 9 and is engaged by a roller or the like 993 journaled in an arm 904 of a three arm lever indicated generally at 905, Figures 3 and 5. The three arm lever 9% is centrally journaled on a pivot post which for convenience of construction may be a downward extension of the pivot post 713 of the jawrelease mechanism and operator mechanism '7.

The other two arms 9% and 907 of the three arm lever 95. 5 are diametrically opposite in their extension from the hub center of the lever and are linked by adjustable links 9% and 9%, respectively, to other levers in this retraction and belt-feed mechanism.

As was mentioned above, opposite halves 801 and 802 of the pad assembly and polishing surface belt mechanism were substantially identical and therefore only one half, the section Sill, was described in detail in assembly. Similarly, the retraction and belt-feed operator mechanism 9 in addition to that part of the same which was described above, includes substantially identical sections one for each half Sill and 3&2 of the polishing pad and belt system. Therefore, for purposes of simplicity, only one half will be described, and that half will be in conjunction with the section 8%1 described in detail.

The link 9% pivoted for horizontal pivotal movement on the arm 9% of the three arm lever 9% is pinned at its other end to one arm 91.6 of a retraction lever 911 through a pin or the like 912, Figure 5.

The retraction lever 911 is journaled in the horizontal upper flange of the carriage plate 803 for substantially horizontal rotation and at the end of its other arm 912 pivotally carries a universal coupling block 913.

A retractor rod 914 is threadably connected or similarly swivel connector 917 pivotally pinned or the 'like to the universal'couplingblock 913 for limited pivotal movement between the ears on the arm 912 of the lever "911.

The forked coupling member "917 is mounted for substantially vertical pivotalinovement about a substantially horizontal axis. The limiting member 915 is provided witha shoulder orthelike "918 between the arms of the forked member 917 to seat against the bight section 916 when the fork member is pulled to a retracted position thereby to pu'llthe retracting rod914.

Attire other end ofthe retractingrod914 it is pinned "to a small pivot block 920 which is in turn pivotally pinned perpendicularly to the pad carriage 808. Abufifer 'spring92l is carried on the retracting rod'914 between the forked connector member 917 and a spring compression adjusting nut 922 threaded onto the rod 914.

The universal coupling block 913 also carries thereunder a feedrodblock 930 which is secured thereto by any convenient means such as stud and boltor machine screw or the like 931. The block '930 has a passage therethrough, not shown, through which passes a belt feeder rod 931. The passage through the block930is preferably substantially larger than the diameter of the rod "931 and is still further enlarged on opposite faces of the block 930 to seatingly accept substantially spherically " faced abutment washers 932 and 933 on the rod 931. The feeding rod 931 is also threaded for a substantial portion of its length andla pair oflocking nuts934 and 935 "do threadably engage the same and'adjustably retain the spherical faced washer 933 thereon. Behindthe locking nuts934 and 935 the threaded end of the rod 3931is substantiallyfree; at its other endthe rod 931 ispivotally connected to a pivot link936 which isin turn perpendicularly pivotally connected by a pin orthe like to an ear or the like937 on aplate930 which is journaled on'the shaft939 for the feed roller 844. A buffer spring"940 is carriedbetween the second substantially spherical faced seating washer932 and adjusting nut 941 threaded onto the rod931.

The feed roller844 has a serrated disc or wheel or ratchet wheel945' secured thereto for rotation therewith.

The teeth of this ratchet wheel 945 are engagedby a "947' mounted between the pawl 946 and aspring backing member 94% mounted on the plate 933.

A similar construction at the take-up reel '834 includes a plate 950which is journaled about the axis ofthe reel 834 and a serrated disc or ratchet wheel1951lmounted for fixed rotation about the axis of the reel834 together with the reel 834. A pawl member 952 is 'pivotally secured to thelplate 950 and is biased into engagement withthe teeth of the ratchet wheel'951 by a spring or the like953 which also engages a mountingblock or similar device 954 secured to the plate 950. A link955 is pivotally engaged with the plate 938 at one endand 'the'plate950 at the other end.

As previously pointed out, the other section'802 of the polishing surface pad and reeling assembly is identically and oppositely equipped with these above-identified and described retracting and reelinglmembers in proper association. With both of the sections 801 and 802 so equipped and constructed and linked together for equal "and opposite retraction and belt-feeding through engagement with the cam 901 and travel thereacross. Automatic retraction pad members and automatic feeding of new increments of the polishing belt maybe efiected at the operator station and at otherpreselected positions about the periphery of this turret-type polishing machine.

The cam 901 with its camming face 902 is so shaped thatas thepolishing unit 2a approaches the operator station about the machine 1, the roller 903 onthe lever 905 encounters a region 901a of substantially reduced radial 14 extension on the cam 901. The camroller 903 following ,the'surface902 of=theicam901 into the area'901a causes the lever 905 to rotate substantially horizontally about the axis of its supporting post, an extension of the post 713, thereby pulling the, links "908 and 909 inwardly towards the center olthe polishing unitZa under the .force of bias spring 905'.

"pawls 946 and 952 "945and951 operate'to-also rotate those ratchets coun- While the cam roller 903 is riding on the earn 901 at the areathereof whereit is of greatest radial extension, as at With, the polishing pads are positioned in their closed or actual polishing "positions as viewedfrom the top in Figure 5 and from the front in Figure 4. When the cam roller903 is ridingon the face902 of the cam inthe region 9010 thereof, the polishing pads are retracted to the position seen thereforhin Figure 6; movement of the pads from the position ofFigures 4 and 5 to the position ofFigure6 is effected when the cam roller passes from the area 901b' tothe area1901a and each section 801 and802 operates precisely symmetricallylso that only one of the same need be described for clarity.

Continuing now with the operation of this system, the

link'908 having been drawn' towards the center of the polishing unit2a pivots the lever 911 so that the arm 912 thereoflmovesoutwardlyfrom the center of the polishingunit. The arm 912 of the'lever911 moving outwardly draws with it the retracting .rod914 and the belt feeding rod 931. The polishing bracketand its associated parts are drawnbackward or'retracted with the retracting rod 914' and the cam 'roller'817 rolling on the camming surfaceor clamp-release camsurface 818 of the clamp release'cam 819 .opensthegjaws 8l4and 8150f the belt clamp'813.

Atjthe same time, while thebelt feed rod 931 is drawn rearwardly, theplates"938and9'50 are rotated clockwise as viewed in Figure '6. Through this movement of ,the

"plates938 and 950the"pawls"946 and952 are also rotated "tracted from'the workpiece "10 and bothof the belts 804- and 805 are released fromrtheir associated clamps on "the pad carriages808 and "809. At this time the feed mechanism is alsococked for feeding a new increment of thepoliShingbelt to thetpolishing faces of thepads 806 and 807. The belt is fed forwardly and the polishing padsare again urged into polishing engagement withthe 10 as the unit 2a leaves the operator station.

mechanism 5 and a new workpiece Now, as the'unit 2a passes out of the operatorstation the cam*'roller"903 is again urged outwardly ,by an increase-in the radial extension of the cam901 (note in visible dottedhline illustration of'cam 901 in'Figure 71) thereby urging the linkage to the position seen therefor in Figures 4'and 5. 'By effecting this closure of the pads and pad carriage mechanisms, the plates 93 8 and950tare rotated counterclockwise, as viewed in"Figure 6. The engaging the serrated ratchet plates terclockwise thus. rotating belt-driving wheel 844 and take- -up"spool"834in a counterclockwise direction pullingthe belt 804 forwardly by a preselected increment from the supply reel830. The increment .isjpreferably sufficient to present a whole new polishing surface over theface of the resilient pad 806. At the same time that the pad .car-

riages808 and 809 are moved to their polishing positions the jaws 815 and814iof theclarnp 813i areclosedunder theforce of the biasing member 820 and permitted to so 'close by thecam and roller, group 8l9jand 817.

"Toprevent the padsf806 and 807 .frombeingforcedinto too tight an engagement with the work-piece 10, adjustable stop means 850 is provided on the outer face ofithepmain efficiently.

carriage plate 803 between the carriages 808 and 809. The stop means 850 preferably carries a pair of adjusta'oly threaded screw and nut combinations 351 and 852 posttioned as shown in Figures 4 and 6 to butt against the facing edges of the carriages 808 and 809.

Adjustment of the stop means 850 may possibly require the carriages 808 and 809 to stop prior to completed radial outward movement of the roller 903 on the cam 901. The roller 903 is nevertheless permitted full movement since the rods 914 and 031 are loosely shock mounted through their appropriate brackets and continued outward movement of the roller 903 merely urges the block 930 to shock-absorbing engagement with the spring 940 and the forked member 916 into shock-absorbing engagement with the spring 021.

This spring-forcing mean also assists in mantaining the polishing surfaces in resilient engagement with the faces of the workpiece 10, as the workpiece is reciprocated and oscillated as described above; and permits selfequalizing of the pressure of the belts and pads against the surfaces of the workpiece.

In order to insure proper high surface polished finishes to the workpiece 10 which may be a turbine blade or bucket or vane or the like having opposed complex arcuate surfaces, the polishing machine 1 is provided with means to feed new increments of the polishing belts to the polishing pads at preselected points along the periphery of the machine. Therefore, cam 901 is provided with additional area of reduced radial extension at spaced points therealong. The particular number of these areas is not critical, it is preferred that the cam 901 be provided with two such areas 9010 and 901d of short arc length and of a radial dimension substantially identical to the radial dimension of the area 901a. Note Figure 1. As the polishing unit 2a approaches each of the areas 9010 and 9010! individually, the areas 01c and 901d being spaced apart a distance substantially equal to the distance that they are each spaced from the operator station, the belt-feeding and pad-retracting mechanism is operated quickly to retract the pads, feed the belt forwardly by a slight increment, and reclose the pads and the two polishing faces onto the workpiece 10 which may continue to reciprocate and oscillate or which may be stopped by actuation of the magnetic clutch or deenergization of the motor 201 as desired.

It should also be noted from Figures 1 and 5 that at the operator station the reduced radial extension area 901a of the earn 901 is of greater arc length than the arc length of the cam 701 for the work-release operator mechanism and extends in both directions, clockwise and counterclockwise from the end of the cam 701. This dimensioning of these earns is provided so that the workpiece polishing pads and polishing surfaces will be retracted from the workpiece prior to stoppage of movement and/ or release of the workpiece by the workpiece release operator mechanism. In this manner and through combined reciprocation and oscillation of the workpiece, the workpiece is polished to a high surface finish without scratches, mars or flaws thereon.

From the above detailed description of the mechanical construction of this preferred system embodying the principles of the present invention and from the described detailed description of the operational characteristics of portions of the machine individually, it will be understood that the machine 1 for polishing turbine blades or other workpieces is operative to uniformly polish such workpieces rapidly and economically. As the turret of the machine rotates, the work-holding mechanism is reciprocated and oscillated thus reciprocating and oscillating the workpiece thereby avoiding travel of the workpiece through a single defined path. By such reciprocation and oscillation surface mars or scratches due to possible imperfections in the polishing surface itself, or from such other causes as dirt or grit or the like is avoided most In addition, this turret-type machine is opit"? erative to advance new polishing surfaces to the workpiece for polishing the same at a number of points about the periphery of the machine, thereby further insuring high surface polishing.

Further, polishing machines embodying the principles of the present invention, such as the turret-type polishing machine 1, are operative to release and/ or eject the workpiece at any preselected position above the periphery of the machine which position may be considered as a stop station or operator station for the machine. The particular work-holding and ejection mechanism is operative, as described, to eject the workpiece by opening the jaws the necessary spacing therefor and to thereafter close a sufficient distance to permit insertion of a new workpiece and hold the same and to still thereafter clamp the same. The polishing surfaces of this embodiment of the principles of the present invention are retracted from the workpiece before it is released and stopped and are closed upon the new workpiece after it has been clamped for polishing movement.

It will be understood from the foregoing that numerous modifications and variations may be made without departing from the true spirit and scope of the novel concepts of the present invention. 1 therefore do not Wish to be limited to the precise construction shown and described but intend by the appended claims to claim all suchmodifications and variations as fall within the scope of my invention.

I claim as my invention:

l. A polishing machine comprising, a support mechanism, a rotatable member carried by said support mechanism, a plurality of polishing devices secured to said rotatable member and rotatable therewith, cam means secured to said support mechanism, a workpiece holder in each of said polishing devices, workpiece polishing means operably disposed to engage opposite faces of a workpiece held by said holder, means to retract said polishing means from a workpiece, means to release a workpiece from said holder, first cam follower means to actuate said retracting means independent of said release means, and second cam follower means to actuate said release means independent of said retracting means, said cam means and said first and second cam follower means cooperating to actuate said retracting means prior to actuation of said release means.

2. A polishing machine comprising, a support mechanism, a rotatable member carried by said support mechanism, a plurality of polishing devices secured to said rotatable member and rotatable therewith, cam means secured to said support mechanism, a workpiece holder in each of said polishing devices, mechanism to reciprocate said holder, mechanism to oscillate said holder, workpiece polishing means operably disposed to engage opposite faces of a workpiece held by said holder, means to retract said polishing means from a workpiece, means to release a workpiece from said holder, first cam follower means to actuate said retracting means independent of said release means, and second cam follower means to actuate said release means independent of said retracting means, said cam means and said first and second cam follower means cooperating to actuate said retracting means prior to actuation of said release means.

3. A polishing machine comprising, a support mechanism, a rotatable member carried by said support mechanism, a plurality of polishing devices secured to said r0- tatable member and rotatable therewith, cam means secured to said support mechanism, a workpiece holder in each of said polishing devices, a pair of resilient pad members, a separate polishing belt trained over each pad member to provide polishing surfaces contiguous with said pad members, a supply reel for each belt, -a take-up reel for each belt, means to periodically advance said belts over said pad members by an increment sufiicient to supply a fresh polish-ing surface thereover, means to retract said polishing surfaces away from a workpiece in for active said holder, means to release a workpiece from said workpiece holder, first cam follower means to actuate said retracting means independent of said release means, and second cam follower means to actuate said release means independent of said retracting means, said cam means and said first and second cam follower means cooperating to actuate said retracting means prior to actuation of said release means.

4. A polishing machine comprising, a support mechanism, a rotatable member carried by said support mechanism, a plurality of polishing devices secured to said rotatable member and rotatable therewith, cam means se cured to said support mechanism, a workpiece holder in each of said polishing devices, opposed resilient polishing pad members on opposite sides of said holder, a separate polishing belt trained over each pad member for presenting a pair of opposed polishing surfaces, a supply reel for each belt, a take up reel for each belt, means to periodically advance said belt including a ratchet and pawl assembly arranged to drive said take-up reel, means to retract said polishing surfaces from .a workpiece carried by said holder, means to release a workpiece from said holder, first cam follower means to actuate said retracting means independent of said release means, and second cam follower means to actuate said release means independent of said retracting means, said cam means and said first and second icam follower means cooperating to actuate said retracting means prior to actuation of said release means.

5. A polishing mechanism for polishing opposed surfaces of a workpiece comprising, a workpiece carrying mechanism, means to simultaneously impart both reciprocatory motion and oscillatory motion to said carrying mechanism, resilient polishing pad member disposed on opposite sides of a workpiece in said carrying mechanism polishing belts trained over said pad members respectively polishing by the portions thereof contiguous pad members thereby forming polishing surfaces, and means to periodically advance said belts past said pad members by increments sufiicient to position a new polishing portion of the belt thereover.

6. A polishing mechanism for polishing opposed surfaces of an elongated workpiece comprising, a workpiece carrying mechanism including a track member, a ram member slidably arranged and guided in the track member, mechanism to reciprocate said ram member in the track member, further mechanism to transversely oscillate said track member and said ram member, a pair of resilient polishing pad members, a polishing belt trained over each of said pad members for active polishing by the portion thereof contiguous with said pad members, a polishing belt supply reel, a polishing belt take up reel, and means to periodically advance said belts past said pad members by an increment sufficient to train a new polishing portion of said belt over said pad member, said means to periodically advance said belt including a ratchet and pawl assembly arranged to drive said take-up reel by a preselected increment.

7. In a polishing mechanism operable to polish oppositely disposed complex arcuate surfaces of a workpiece, in combination, a pair of oppositely disposed polishing belts, work-holder means having a releasable jaw mechanism arranged to position a workpiece between said polishing belts, mechanism to reciprocate said workholder means, means to oscillate said work-holder means, a jaw release mechanism, a polishing belt retracting mechanism operable independently of said jaw release mechanism, and means to actuate said belt retracting mechanism prior to actuation of said jaw release mechanism to retract the polishing belts from the workpiece prior to release of a workpiece from the jaw mechanism.

8. In a polishing mechanism operable to polish oppositely disposed complex arcuate surface of a workpiece, in combination, a pair of oppositely disposed polishing belts,

with said jaw mechanism arranged to position a workpiece between said polishing belts, mechanism to reciprocate said jaw mechanism, means to oscillate said jaw mechanism, a jaw release mechanism, a belt retracting mechanism operable independently of said jaw release mechanism, means to actuate said belt retracting mechanism prior to actuation of said jaw release mechanism to release a workpiece therefrom and to operate said jaw release mechanism to grip a workpiece prior to return of the retracting mechanism into position to engage the workpiece with the polishing belts.

9. A turret type polishing machine which comprises a rotatable support, a plurality of polishing units mounted circumferentially around said support, stationary cams disposed around said support, cam followers on each of said polishing units coacting with said cams, workpiece holders on each of said polishing units, a prime mover on each of said polishing units to actuate said holders, opposed polishing belts on each unit, means for pressing said belts against opposite faces of a workpiece carried by said holder on each unit, means for retracting said polishing belts from said workpiece, means for opening and closing said workpiece holder, and said cam followers coacting with said cams to control said means as the rotatable support advances the units around the cam.

10. An automatic polishing machine which comprises a rotatable support, a plurality of polishing units mounted circumferentially around said support, circumferential stationary cams around said support adjacent the polishing unit on the support, a workpiece holder on each unit, opposed polishing means on opposite sides of a workpiece held by said holder, means for opening and closing the holder, means for opening and closing the polishing means, and cam followers on said units coacting with said cams to control said opening and closing means at preselected positions around the work holder.

11. An automatic turret type polishing machine which comprises a carrier rotatable about a vertical axis, a plurality of polishing units mounted on said carrier circumferentially thereof, stationary cams disposed around said vertical axes adjacent said polishing units, each polishing unit having workpiece carrying jaws and opposed polishing belts for acting on opposite surfaces of a workpiece carried by said jaws, means for moving said belt toward and away from a workpiece carried by the jaws, cam follower means coacting with said cams as the units rotate around the vertical axis on the support for first retracting said polishing means, then advancing said polishing belts and thence closing said retracting means against the workpiece and additional cam follower means coacting with said cams for first opening the jaws to discharge a workpiece, thence partially closing said jaws to permit insertion of a new workpiece and thence completely closing said jaws to clamp the workpiece.

12. A polishing machine which comprises a rotatable support mechanism, a plurality of polishing units positioned circumferentially about said support mechanism and carried on said support mechanism, stationary cam means circumferentially fixed to said support mechanism, each of said polishing units including a pair of oppositely disposed polishing means, work holding means arranged to position a workpiece between said polishing means, a work holding release mechanism, means to retract said pair of oppositely disposed polishing means from the workpiece, a polishing surface on each of said oppositely disposed polishing means, means to renew said polishing surface, cam follower means coacting with said means to retract said polishing means and said cam means to retract said polishing means at preselected positions about said support mechanism and further cam follower means coacting with said cam means to coact with said means to renew said polishing surfaces at predetermined positions circumferentially about said support mechanism.

(References on following page) 19 References Cited in the file of this patent UNITED STATES PATENTS Re. 16,141 McDonough Aug. 11, 1925 676,700 Roper June 18, 1901 1,459,085 Black June 19, 1923 1,490,631 Newkirk, et a1 Apr. 15, 1924 29 .7 Raule' Apr. 25, 1933 Moon June 1, 1937 Hamilton July 12, 1938 Indge Nov. 4, 1941 Whitehead Feb. 15, 1949 Dackor et a1 Feb. 7, 1951

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