US2620769A - Means for handling and varnishing electrical windings - Google Patents

Description

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l MEANS FOB HANDLING ANDv VARNISHING ELECTRICAL WINDINGS Filed Oct. 30', 1948 7 Sheets-Sheet 2 A "l l l lNvENToR NATHANIEL B. ORNlTz Dec- 9, 1952 N. B. onNnz 2,620,769

MEANS lFOR HANDLING AND VARNISHING ELECTR IC AL WINDINGS Filed oct. :5o. 1948 7 sheets-sheet 5 INVENTOR NATHANu-:L B. ORNlTz Dec. 9, 1952 N. B. oRNn'z 2,320,769

MEANS FOR HANDLING AND vARNIsHING ELECTRICAL wINoINGs Filed Oct. 30, 1948 7 Sheets-Sheet 4 INVENTOR Dec. 9, 1952 MEANS FOR HANDLING AND VARNISHING ELECTRICAL WINDINGS Filed 0017. 50.' 1948 7 Sheets-Sheet 5 INVENToR NAIHANIEL B. ORNITZ Dec. 9, 1952 N. B. oRNlTz MEANS FOR HANDLING AND VARNISHING ELECTRICAL WINDINGS '7 Sheets-Sheet 6 Filed 001,. 30. 1948 l Ey. J0.

INVENTOR NATHANIEL B. ORNITZ Dec. 9, 1952 N. B. oRNlTz 2,620,769

MEANS FOR HANDLING AND VARNISHING ELECTRICAL WINDINGS Filed Oct. 50. 1948 7 Sheets-Sheet '7 INVENTOR NATHANlEL. B. ORNl-rz l j inf, may f1/u QD 4775749,"

Patented Dec. 9, 1952 MEANS FOR HANDLING AND VARNISHINGV ELECTRICAL WINDINGS Nathaniel B. Ornitz, Pittsburgh, Pa., assignor to Blaw-Knox Company, Pittsburgh, Pas a.. corporation. ofNcw Jersey- Application October 30, 19.48', Serial No.A 57,492

3 Claims.

Thisl invention relates toA a system for quickly andj efliciently carrying out the heating, impregnation and drying of' elec-trical windings. More particularly, this invention pertains toa machine assembly and operational steps for varnishing rotors, stators and the like on a production line basis.

This invention is advantageously employed in carrying out a varnishing process such as that shown in United States Patent No. 2,411,180 or inthe' United States Patent No. 2,417,538. As used in this specification, the terms impregnated and' impregnation refer to the eifects of the immersion in the varnish to` which the windings in question are subjected.

Ina prior practice of varnishing electrical windings, it was customary first to heat a batch of such windings in an oven in which the atmosphere was heated and circulated in a general fashion. The windings were then removed and immersed in a dip tank containing varnish at a lower temperature with machined faces in some casesprotected byr plastic coatings to. prevent varnish from adhering thereto. In dipping armatures particularly, the winding was usually immersed that radial distance inward from the outer periphery whichI upon rotation would impregnate the coil portions of the winding without touching partsv such as an armature shaft at a greater distance-from the periphery. The windings were removed from the dip tank and heated to drive olf any remaining volatile material and to dry the: varnishbase material.

It wasv observed that such heating was inefficient in transferring heat to the windings, was not controllable with any satisfactory degree of precision, didY not result in uniform heating of the entire batch or necessarily of each winding in the batch, and did not raise the windings to the desired temperature in the time which could beV allotted in commercial practice to the heating operation. Moreover, if all of the batch were remcvedfrom the oven in order to begin heating a new' batch, progressive atmospheric cooling occurred as the' heated windings awaited their turn at the dipping tank. Even though the temperature and composition of the varnish solution in the dip tank were frequently checked, as cooler and cooler windings in the heated batch were immersed somewhat uneveny impregnation would result. As a. consequence, a relatively greater amount of.' varnish base material was required to insure meeting specifications, with greater likelihocdf. of. building up a. gummy deposit. In addition. there were no fast, accurate handling means,

particularly with the-heavier' pieces, for trans- Z. ferring the windings from the oven or controlling the depth of their immersionwith precision.

The foregoing difliculties and disadvantages inherent in such a prior practice are overcome by the employment of this invention.

Thus, in this invention, the heating and impregnation. of electrical windings is carried out on a production line basis by progressively heating them in step-by-stepv fashion toa predetermined temperatureat conveyor stations inan oven provided with cooperating directed blasts. or streams of aheated atmosphere which playover the articles at thosey stations. When. uniformly heated, such windings are successively presented to a manipulator station where each is speedily gripped and transported without substantial loss of heat to an adj acent dip-tank having a constant level body or pool ofi varnish therein. This; varnish solution ismaintained underl substantially constant temperature and composition condi'- tions suited to the particular character of impregnation to be performed. Therey the winding is dipped until all of its desired portionsare impregnated. Then it is quickly remo-ved by the manipulatorand deposited' on a conveyor platform farther along the direction cf progression of the articles. The windings are carried forward again on the second conveyor in step-by-step fashion through an oven and dried by similarly directed streams of' a heated atmosphere. Means are provided for closing the ovens during the dwell of the conveyors when the windings are on station and for subjecting the windings to heating and dippingv in asingle synchronized machine assembly until the desired varnishing of the windings has been achieved.

Other objects and advantages of this invention will be apparent from a consideration of the fol-1 lowing description and of the drawings, which are illustrative only,l in which,-

Figure 1 is a view inside elevation of avmachine assembly made in accordance with this invention;

Figure 2 is a plan view of the apparatus shown in Figure 1 Figure Bis an end view of the apparatus shown in Figure l;

Figure 4 is a vertical section taken from the exhaust side of one end of an oven and its adjacent manipulator;

Figure 5 isv a view in side elevationA taken from the pressurey side of the adjacentl ends with the vestibule casings removed, of twoadjacent ovens andthemanipulator interposed therebetween;

Figure 6 is a side` view of one end of an oyen show-ing the, door actuating. mechanism;

manipulative portion of the manipulator shown a Y in Figure 9;

Figure 1l is an end view of the gripping member assembly of the manipulator;

Figure 12 is a vertical section taken on line XII- XII of Figure 11;

Figure 13 is a schematic wiring diagram for use with the machine assembly shown in Figure l;

Figure 14 is a view in elevation of a form of Y nozzle used in ovens made in accordance with this invention;

Figure 15 is a cross-sectional view taken on line XV-XV of Figure 14; and

Figure 16 is a cross-sectional view of another form of nozzle used in this invention as shown in Figure 4.

Y General construction and operation In a preferred embodiment of the invention, windings are successively placed on a conveyor I at station A. These windings are moved in step-by-step fashion through a tunnel-like passage of an oven I I, stopping in the course of their progression therethrough respectively at stations B to J, inclusive. Doors I2 automatically open before movement of conveyor III commences and automatically close when such movement is about arrested so that the windings are in a closed oven while at rest at each station of their progress therein. A heated atmosphere, usually air, is directed laterally across oven I I in continuous blasts through pressure orices fitted with suitable nozzles to convey heat primarily to the windings in respective axial alignment with the streams. Exhaust vestibules I 4 on the opposite side of oven II act to recirculate the heated atmosphere through turboblowers I to the oven. In addition, a countercurrent ow of the heated atmosphere passes longitudinally through the oven from the vicinity of station J to the vicinity of station B. The windings are thereby heated to atemperature somewhat higher than the desired predetermined final temperature and initially reach such temperature at an intermediate station such as station H. The continued heating and soaking at stations I and J results in each winding reaching station K in a substantially uniformly heated condition throughout its mass by an efficient use of the heating atmosphere. Furthermore, each winding successively presented at station K is at substantially the same temperature as the preceding winding, regardless of whether it is of a different character or size.

Each winding on station K is picked up by a manipulator I8 which travels on a way I9 and is so arranged that station K projects and overlaps the adjacent end of the path of travel of manipulator I8. The character of manipulator I8 makes it capable of handling stators, armatures and other forms of windings, which after being gripped are transferred to station L and dipped in the constant level constant temperature pool of varnish solution in dip tank 2l). The winding is usually lowered with accuracy and sureness to a predetermined radial distance inward from the outer periphery thereof. Then it is rotated and automatically at a preselected rate to evenly immerse all portions of the windand oven II.

. results.

ing requiring it. Because of the freedom and facility with which the manipulators such as manipulator I8 move and operate, each winding reaching station K or a similar station can be transferred and treated at the next station before there has been any material loss of the heat which it received in the preceding oven. Since the temperature and composition of the contents of the dip tanks are maintained substantially constant, uniform impregnation of the windings When this invention is used Yto apply different varnish, the winding and dip tank temperatures and related factors must be correspondingly altered and correlated.

Upon impregnation of each winding at station L, it is removed and deposited by manipulator I8 at station M on a conveyor 2|, freeing manipulator I8 for return to station K to pick up the next succeeding winding as it is presented. Station M on conveyor 2l is also adjacent tank 23 but on the advance side thereof and overlaps the path of travel of manipulator I8. The dwell or rest interval between movements Aof the conveyors Ii) and 2| is preferably of sumcient duration to enable a winding to be taken from station K, treated at station L and deposited at station M and to enable manipulator I8 to be returned to station K just about the time such succeed- Y ing winding is there presented. The same relation would also obtain between stations W, X and Y. The movements of all the conveyors and oven doors are coordinated and preferably occur at the same time, although for special purposes it may be desirable to run one conveyor and its related oven doors in predetermined but differing relation to another.

'Soon after the winding has been deposited at station M and while manipulator I8 is returning to station K, doors I2 on oven II and the doors on the other ovens begin to go up and near the top of their travel the next incremental step of the respective conveyors begins. It ends at the next station or index position of the respective conveyors just about the time the doors are beginning to close. In this way, the windings are progressively and successively moved in a production line from heating zone to heating zone with impregnation between such zones so that the entire benet of the temperature differentials between windings and varnish bath is preserved.

The drying baking sections comprising conveyors 2I and 24 and ovens 23 `and 25, are similar in structure and operation to conveyor IG Likewise, the manipulator and way serving station X are similar in structure and operation to manipulator I8 and way I9. Each winding progresses therethrough station by station until it arrives lat station II, thoroughly and uniformly impregnated, dried and baked, and ready to be removed.

The heated atmosphere is supplied in the preferred embodiment by a central, recirculating heater 21 fired by oil or other fuel, connected to ovens II, 23 and 25. The ovens thus receive air or other atmosphere suitable to special purposes heated to the same predetermined degree, although it is entirely possible to have a heated atmosphere either of the same or different character andv temperature independently supplied to each of the ovens. Moreover, although the ducts from heater 21 provide a longitudinal flow of atmosphere through the ovens counter to the'direction of movement of the conveyors, in addiytion to 'the cross blasts, separate heaters for each oven or even forfeach blower' I5. caribe arranged ported by shafts 3:3 journal-ed' inpillow' blocks 1 at each end of' Ia conveyor table 4l). These sprockets ofwhicl'iV there. are two in spaced; relation on each shaft 33 engage the journals of rollers 3.05 at the respective endsl thereof". A sprocket wheel 3l!v is keyed at' one end of one of the shafts 3'3 and is driven by chaingand gear 35;.. Gear 35' is keyedto shaft 3T yand receives its motive powerY from anY electric motor 38' through a .gear reducer' 3Q'. Y .Motor 38 is subject ltothe control of' the limit switches and cams shown in. Figure 13 so. that each movement of belt. 3i) is' for the. preselected lineardistance between stations.

Conveyor Le is supported on tableau over the top surface 4I of' which the belt' 3B' travels between track. angles. returning beneath said surfaceA where the returning reach is supported on idler rollers 4 I Thesides of table III)Y `arelagsfed to the 'oor by panels, d'2' to` prevent. loss of heat. Aliandhole. 421' therein provides access toeach roller M. Oven II' is positioned over table lll, its sideextensions Illa and belt 30 and covers the greater portion` thereofVv intermediate their extreme ends. This oyen` comprises ya series of heating.. chambers, each openingv into onev another in` endwise. fashion to yform a continuous tunnel-like passage, the intermittently moving floor. o f which. is the upper reach, of belt. 3B. These. chambers are three in number and respectively include stations B?, C and D; stations E, F and G; Vand stationsl-Lwand- J The structural frame of ,oven II comprises a series of vertical end members 43 and. intermediate vertical frame members. 44. Horizontal structural mem.- bers4'5- are. welded or riveted` to members d and 44 at. suitable intervals along the length of the oven, Yto complete. the. rectangular structure. suitably insulated panels 41 close. the. tops of 4all oli' the chambers in oven I-I. Insulated panels 50 close. the sides of.- the chambers by beingv bolted to the vertical frame members, The space between the lower ends. of panels and. the sides of` the. upper reach of belt 39. is. closed by side extensions4 l la.. Panels. 5.0. also support the casings. for pressure-vestibules 5iy and. suction or exhaust vestibules I-ty yaixed thereto, there being a. pair. of such vestibules for each chamber in eachoven.. asshown in Figure 2. The. upper end of each vestibule 5I' narrows. into `a duct which is joined'. with acorresponding opening in apressure. duct 521 leading. from the pressure side of a blowerY l5. Exhaust vestibules. I4 are. connected to the intake ofy blowers. I5.. by ducts. 53.. These blowers I5-are of standard designv and are operated by electric motor 5d. acting through gear reducers. 55- Through each panel 5.14 onY the pressure orblast side. of oven. Il. there area series oi three.A orifices 55'.V The distance between the centers of the orifices in a.r single chamber and between the adjacent orices of adjacent chambers is the same and corresponds to the preselected linear-distancewhich conveyor I- travels between. each rest interval. Hence; byl placing an electrical winding with its center above the index: position Yon conveyor Il) at station.A .ini a cradle 51,; -at-eachstation within oyen .HT cach 6 Winding so placed: will be.- substantially centered relative an. orifice. 56. Cradles 51 are usually shortV lengths of channel iron, the anges of which are suciently deep to hold the winding upf: fromthe web of the channel so that the heated atmosphere in the ovens will reach substantially the; entire winding. They are positioned on the flat bed of; conveyor I El by reference to an index: mark made on slats 3l or by experience 0 in accorda-nce with the spacing between the` orices 551 A'. laterally directed continuous4 blast of heated atmosphere is obtained by the use of orices- 56 squarely against. and along the axis of the windings during the time-particularly thatfsuchwind.- ings. are atthe: stations within the-oven I I. For additional= directional restriction of` the. blast, short honeycomb nozzles 58. 'and lattice nozzles 55 may be used as sho-wn in Figure 4; Nozzles 58 comprise a bundle of axially disposed short lengths of pipe ll-ing someof theorices 55. In nozzles 59, the vertical louversy in the lattice are deected slightly toward the` center of the` oven.

The: laterally directed streams. of heated atmosphere. exhaust through the vestibules. I4, whence the mass of atmosphere returns tothe blowers- I-5 for recirculation. There is intermingling of the various streams and any longitudinal current of atmosphere some of which also passes out. of oven II through exhaust line I1. The panels 50 comprising the inner side of the vestibules I4 haveV orifices 6I therein, generally corresponding in size and arranged opposite to the orices 56. If larger exhaust passages are desired, the enti-reinner side of each vestibule I4 may be opened through its panel 50 into direct communication with the interior of oven I I. The heated atmosphere is preferably heated air which may be humidied, ltered or otherwise treated and which may also be used to carry some protective or benecial ingredient if desired. Normally, the only air which needs to `be added to the Vrecirculating mass will be the make-up due to any air lost each time the doors of the oven are opened and to air bled oii to the outside for reasons of safety. Less air will pass out when the oven doors are open if no longitudinal' current olf' air is provided and' in some cases partial baffles" may be used to minimize any loss. The heater 2'! supo-lies' air heated to a predetermined temperature through line 62 and pressure header 83 by principally recirculating air drawn into exhaust header 56 and by circulating any new or make-up air ywhich also generally enters through the oven doors,l when they are open. Pressure lfieaderI 63j communicates with the delivery end of the respective ovens through lines I6, $4 and 65, respectively while exhaust header or manifold 66 communicates respectively with the ovens through lines I'I,.6I and 58. This effects a countercurrent axial now of air through the ovens although the headers may be arrangedv for some purposes to give concurrent axial, flow. Any such ilow is in. addition to the directed cross. blasts through the pressure oriiices. The axial now while not necessary in all cases for eicient use of this invention, does provide, particularly with larger electrical windings, a .means of overcoming any tendency of the windings to reach a higher temperature' on the end or side nearer the pressure vestibules duringtravel on thev conveyors. An exhaustfan 69 connected to. header 65 maintains suction for the axial recirculation and for-fresh intake.

S'paced outwardly from each of the end vertical structural members 43 and substantially parallel thereto is a strip I connected to members 43 by brackets 1I. Strips 10 with the respective members 43 form a pair of parallel vertical guide grooves at each end of oven II for rollers 'I9 of doors I2. Each insulated door |2 is hung on two endless chains l2, one at each side of each door, respectively connected to the top and bottom thereof as shown in Figure 6. Each pair of chains 72 is suspended from sprockets 'I3 supported on shafts 'I3' journaled in pillow block bearings attached to frame members 43. The lower end of chains I2 passes around sprockets '|4 respectively. Hence, rotation of sprockets 'I3 and 'i4 in one direction or the other correspondingly raises and lowers the doors I2 to the limits of their movement. The construction and operation of the doors on ovens 23 and 25 are the same.

The four edges of each door I2 are formed from angle bars I8 supporting rollers I9 at the top and bottom of each door on each side for engagement with the aforesaid guide grooves. A metal guard 8| is provided for the rea-r of members 43 to cover some of the exposed portion of the chains 12. As the doors respectively open and close, rollers 79 also engage the limit switches .illustrated in Figure 13.

A brake-type reversing motor 83 when actuated operates a driving gear 84 through a gear reducer 85. Driving gear 84 in turn rotates a driven gear 86 through chain 81 thereby turning shaft 88 and sprockets 'I4 to raise or lower the doors I2 automatically and in synchronism with conveyor I0, and with the operations and movements of the remaining sections of the assembly.

Electrical circuit diagram A suitable electrical circuit for the operation of a machine made in accordance with this invention is illustrated in Figure 13. Modifications of this circuit are matters within the skill of the electrical art and may include control buttons to prepare the circuit and to stop all movement of the doors or conveyor in any or all of the ovens at the behest of any attendant at any position along the machine. In addition, in normal operation all of the ovens and conveyors in a single assembly will be interlocked and function at the same time and in the same manner, or in such relative and sequential operation as may be preselected.

In Figure 13 doors such as doors I2 of the preheating oven II shown in Figure l with its conveyor 30, are shown in outline. Essentially, substantially constant speed motor 98 actuatesY a constant speed timing camY |00 through a suitable transmission 99 to periodically and momentarily close a starting switch I0 I. Thereupon relay contactors I02u and |03u are energized closing the four sets of terminals shown for each. These contactors are sealed in respectively through normally closed limit switches 90 and 9|. Limit switch 9| has a lower set of terminals which are normally open. The two intermediate sets of terminals of each contactor close the circuit to the brake-type reversing motors 83 operating on the S-phase current from lines A, B and C. These motors operate the respective pairs of sprockets I4 in the direction which will raise doors I2. As soon as doors I2 begin to go up limit switches 92 return to their normally closed position. l

Just before doors I2 reach the upper limit of their travel, they respectively strike limit switches 93 which are normally open and in series. Immediately a circuit is set up through the lowermost pair of terminals of relay contactors |02u and I03u, normally closed limit switch 94 and relay contactor |04. The energization of relay contactor |04 starts the single phase motor 38 which drives conveyor belt 30 through gear reducer 39 and sprockets 32. Motor 38 is then sealed in through limit switch 95 which was open when conveyor 30 was at index or rest position but which limit switch presently closes when it engages the cam rise of cam 91. A second cam 96 operates on the same shaft as cam 91 and has a dropped or dwell cam portion slightly in advance of the dropped or dwell cam portion of cam 91. These cams are rotated at a preselected and integrated rate of rotation by motor 38 through a suitable transmission. The same results may be obtained by using laterally extending overlapping shoes on the conveyor instead of cams to actuate limit switches 94 and 95.

The continued raising of doors I2 causes them to strike limit switches and 9| soon after the engagement with limit switches 93, breaking the normally closed circuits through limit switches 90 and 9| and deenergizing relay contactors VI02u and |03u, stopping both motors 83. Motor 38 continues to operate meanwhile until the predetermined length of travel of conveyor 30 to its next station or indexed portion is completed.

Just before the completion of travel of conveyor 30 in each of its incremental movements, limit switch 94 is opened by cam 96 and thus deenergizes the coil in relay contactor |04 causing it to drop breaking the upper two sets of contacts and remaking the lowermost. The making of the lowermost contact of relay contactor |04 energizes a circuit from line A through the lower set of poles of limit switch 9| made when the ad- -jacent door I2 reached its upper limit, to the coils of relay contactors |02d and I03d severally connected through limit switches 92`which are normally closed, to line B. The energizing of contactors I02d and 03d, which are sealed in through the uppermost pair of contacts, restarts motors 83 in the opposite direction to lower doors I 2. About that time, limit switch 95 is opened by cam 91 stopping motor 38 and conveyor 30.

As doors I2 reach their bottom limit of movement they strike and open limit switches 92, thereby deenergizing relay contactors |0211 and I03d and stopping motors 83. This cycle is periodically repeated due to the continuing rotation of timing cam |00. The use of additional such timing cams on the same shaft with cam |00 0r on separate shafts synchronized with cam |00 will provide for identical movement or such other synchronized relation among all the ovens andv conveyors in the machine of this invention as may be desired. Other circuit arrangements adapted for elective interlocking or individual control of the respective ovens and conveyors may readily be included. An emergency switch |05, of which there may be one or more at each end of each oven as well as on a central or remote panel is provided to stop all movements at any stage in case of need.

Transfer and dipping mechanism The transfer and dipping mechanism comprises the manipulators and ways such as manipulator I8 operable on its way or track I9 in combination with the ovens |I and 23 to successively pick up and dip electrical windings from oven II before aecomo there has been Yany time 'for them rto 'lose any u substantial portion of -their heat, and then to deposit them fon 'conveyor '2| successively without any further substantial loss V'of heat due to A hood can be placed over the `manipulators *and their tracks between the associated Vovens to -collect and exhaust such volatile vapors.

'Way -I9 comprises a'horizontal -slab ||f9 to one side and xparallel to 'the axis =of movement of conveyors I and 2I, having ya rack supported along the -upper longitudinal medianlir-ie thereof. Laterally extending flanges ||f2 are .integral `with slab |||-0 and engage 'the rol-1ers -I I3 to support manipulator If'Il as `it `moves back and forth on track I9. Slab III) in turn is supported -on and afxed 7to channel beams I4 forming va hollow beam having a central longitudinal passage ||5. Beams I-'I4 are welded -or bolted-to laterally -ex tending Ygirders |16. These girders in turn are fastened to ibase plates |'|1 Imounted von -grooved rollers -'||-'8 which-rollen tracksections fl-I. Stops |270 'limi-t the 'lateral movement of 'rollers |-"|-8 -and consequently of `manipulator t8 `'and `its track I 9.

Lateral g-irders H16 are spaced `to Aspan -dip vtank 250 'and its attendant equipment. Support *is afforded the -girders i'IfI-I at the rear ends thereof by plates |2| mounted `on grooved rollers |l2-'2 which roll =on track -sections |23.

The two Loutermost girders ||f6 have `bea-rings |24 thereon rotatably supportingathreaded shaft |25. One-end of each shaft |25carriesa sprocket |26 keyed thereto. Anfendless sprocket -c'hain @l2-1 engages other sprockets |26 journal-led on rstub shafts ft2-8 in passage ||f5 `in such fashion that almost all of chain |21 is within the passage. Intermediate the innermost -'girders IIB the lower anges `of channels `IM are-separated suiiiciently to permit vchain :l2-1 to yengage ja sprocket rgea-r `F29 keyed toshaft 29" Awhich is Vjournaled in bearing |31). Bearing |38 is fadjustabl-y affixed to the underside of Achannels 3| |11 by threaded :studs 13|. By 4adjustment of bearing |130, chain |21 "can be kept taut. fSlide plates @|32 with suitably vdepressed ends support-ably guide the lower half ofv chain |21 during movement thereof. 'The forward 'end of shaft' |259 is machine finished in a conventional polygonal form for l'engagemez-it with a corresponding `'opening l-in the end A'of turning handle |33.

JA threaded follower NAf-engages the threads of each shaft' |25. `Since follower |134 is bolted to an'upstanding bracket |35 fastenedto the-floor., movement rof handle |33 results inthe 'transverse movement of vgirders '|I-6, manipulator 'I'S and track `H! in ya direction `depending -upon the direction of rotation of handle |33'. In this way, the machine of `this invention `is 4ableto vhandle agreater diversity-of sizes'a-nd typesof electrical windings including stators lwith hollow centers and armatures having Aboth symmetrical and asymmetrical shafts. Thus in Figure 9,#mani-pulator I8 isgripping a large armature :|536 shown in :chainline outline. In-.the i-usual handling of various stators, the manipulator would have sufficient .scope lif its vertical center line -ooincided with'position'B'.

Manipulator l"|"8 vhas a ibase `p'lateorcarriage |40 with .depending iianges I 4| which `overlie nanges- LIZ of -slab Illu. L-Ro'llers ||3 are rotatably 'supported von stud shafts affixed to 'the inside of nanges I4-I in and closely engage the upper and lower horizontal surfaces of -anges `|-|2 to provide substantially free rolling relation between manipulator I8 and its track i9. The construction andoperation of the manipulator and wayat station vX are identical to manipulator 48 and way `|'9.

Two spaced ver-tical ways 4'|42 are .aiixedito fearriage 'IMI Yand lreceive added rigidity from bracket members |43. Ways |42 are capped 'by aplate |44 which 1in turn supports a `double-acting hydraulic cylinder |135.

A -pinion 4gear |546 iskeyed to -a shaft N1 jou-.rnaled in brackets 1| 3 v.and rotated lby La hand wheel IS. vPinion gear |46 engages rack III so thatthe turning of hand wheel |48 moves carriage |40 along track I?! .in the one ydirection l or the other.

A crosshead Iwengages and is adapted to move.

vertically lin the vertical Way-s M2. This crossback sides to slidably engage the inner edgesof the ways |512 and -a l'barrel 152. Amandrel-shatt |53 is lin turn s'lidably -bu-t not rotatably lvsupportedv in barrel 4|52 `for :movement trai-isverse Sto the direction lof 'mo-vement of the :conveyor-s. Along .the top ,of shaft 153 at lthe front thereof a rack |56 is mountedfand projects iinto a correspondingrecessin the uppermost portion o'f barrel |52. Rack |54 .is engaged by -a pinion lgear 455 turnedzby a 4handle |56 supported-onabracket |51 aixed to crosshead Ill-9. 'When handle `'|515 .is turned, shaft 1153 moves through crosshead |149 transversely of track t9.

Shaft .|53 has a hollow -bore land Yrotatably rvsupports therein a cylindrical spindle |58. 'Thematerial and machining of the bore through shaft |53 and-of the exterior of spindle .|258 is such as to provide easy operation. Asprocket gear |59 is keyed to the frontend -o-f yspindle |58, the hub of which gear with -ange |60 vat the rear of spindle |58 `causes the spindle to follow any transverse movement lof shaft |53. "Sprocket |59 -is actuated .by chain |559 through a driving fgear sprocket -Itl aiiixed to the shaft of anhydra-ulic motor ISI. This motor is mountedon-adepending apron -I 62 carried by the-frontofshaf-t L'I 53. A metal `protecting guard |63 -encloses the upper portion of sprocket 159. Sprocket |59 is held against spindle |58 yby-a nut -I 64.

A ychuck |65 is bolted to flange -IG at rthe rear end vof lspindle |158 and is rotatable therewith. The rearward face of-chuck yI 65 hasslotted recesses ISS in which gripping members "|61 :in the form of bent levers Yare pivot-ed Von bearings |68. Levers +61 have outwardly extending arms |69, the tips of which `carry friction plates |10 for gripping 'action upon `outward movement of the arms and friction plates IH upon Yinward movement of the arms 'towardithe axis of chuck T65. These friction plates lare vmade `of 'brass or of strong non-metallic, non-markinggmaterial; 'They are pivoted to Ythe 'forked ends :|12 of arms |69 as shown in Figures 11 and 12. Intermediate the ends of levers |61 Yare projections '|13 by means of which arms itt "are Ajointly given their synchronized inward or outward gripping movement.

A shaft |14 extends through a borealongthe |11 in chuck |65. 'Thrust bearings 1| .18 and 419 bear against 4the respective sides of projections |13. The other side of bearings |18 is abutted by an enlarged end |16 of shaft |14. Bearing |19 is held by a washer |86 and nut I 8| on the threaded end of a stud |82 screwed into end |16 of shaft |14 Hence, when hand wheel |15 is turned, shaft |14 and stud |82 moving together either close arms |69 by moving forwardly or spread arms |69 by moving rearwardly. The threaded portion |16 on shaft |14 is of suflcient length to allow for adequate movement cf arms |69 for the variety of work to be done.

Between the vertical ways |42 there is a bifurcated cantilever support |83 which has integral bent portions |84 thereon bolted to flanges |56 of crosshead |49. The outermost end of the support |83 meets and is joined to an I-beam type of trolley rail |85, extending horizontally and rearwardly of the machine transverse to the track |9. A closed loop sling |86 in turn is supported by rigid straps |81 depending from the shafts of rollers |88 respectively engaging the lower flanges of beam |85. The lower end of the trolley sling |86 is recessed to accommodatetwo oppositely disposed and closely positioned supporting rollers |89 which rotatably support any member, such as an armature shaft as shown in Figure 9. A rod |90 is hooked at its rearward end to sling |86 and is slidably guided by strap |9| so that upon pulling forward end |92 thereof, trolley sling |86 is positioned to accommodate varying types and sizes of windings. When processing conventional stators, sling |66 is pushed to its rearmost position and is not used.

A lower ball socket block |93 is fastened to the top surface of barrel |52. An upper block |64 is bolted to block |93 after being assembled with the ball bearing |95 integral with the lower end of a piston rod |96. Piston rod |96 passes through an opening plate |44 and through a suitable packing gland |91 at the lower end of cylinder |145, terminating inpiston |98. Ports |99 and 266 are provided in cylinder |45 on opposite sides of piston |98 to lower crosshead |49 and attendant parts when hydraulic fluid enters through port |99 and to raise them when hydraulic fluid enters ports 260. A conventional manually operated hydraulic valve connected by flexible hosing controls admission to and exhaust from each of the ports and secures a steady and accurate elevation or lowering of arms |69 to that vertical position in which crosshead |49 is to be held by setting the said hydraulic valve. A conventional hydraulic valve is also used for starting, operating and shutting offhydraulic motor |6| to which it is connected by flexible hose.

Dip tank is supported on the floor on legs 26|. Varnish fills tank 26 and preferably is held at constant level and substantially at constant temperature and of constant composition. By controlling the rate of recirculation of varnish solution from a storage tank 263 by means of a pump 264, some varnish in tank 26 will overow into basin 265 whence it returns through line 206 to storage tank 263. Such overflow maintains a constant level. The solution in tank 263 is cooled by cold water cooling coils to the predetermined temperature it should have before being returned to tank 26 through line 261. The tank assembly at station X is the same as that at station L which has just been described.

Because of the three dimensional translatory movement available to arms |69 because of their mounting in manipulator |8, a wide range of different sizes and types of electrical windings can readily be handled and accurately dipped to any chosen radial distances extending inwardly toward their centers and for preselected periods at chosen rates of rotation. Upon completion of the rotation necessary to impregnate all parts of the winding held by arms |69 at vthe time being, crosshead |49 is raised, hand wheel |48 is actuated to advance the winding to the next station, station M, handle |56 is turned to effect transverse movement of the winding until properly positioned over a cradle, crosshead |49 is lowered to deposit the winding on the cradle, and hand wheel |15 is Yturned to disengage levers |69. Rotation of handle |56 theniwithdraws the mandrel and gripping members from the vicinity of the winding so that the manipulator can be returned immediately to station K to be ready when the next winding comes out of oven In one operation of a machine made in accordance with this invention armatures and stators for unit horsepower motors are heated and varnished.

Operation of an illustrative embodiment In one embodiment, which is mentioned soley for purposes of illustration and without the scope of the invention being limited thereto, the machine is built for a linear travel of the conveyors in each incremental step of about 20", at a rate of speed of about 30' per minute. The dwell or rest interval between each such movement is three minutes so that a winding is in each oven about 27 minutes. All ovens and conveyors in the machine operate in unison.

Heated air is passed through the pressure orices at a linear velocity of approximately 3600 feet per minute and no forced axial flow of air is used. This air is heated to about 1000- degrees F. independently in this case by electrical means connected to each of the chambers. All ovens, conveyors and air circulation equipment are lagged to prevent loss of heat.

By the seventh station, coresponding to station I-I in oven the windings initially reach a temperature of about 340 degrees F. and at station K they optimally have a temperature throughout of about 320 degrees F. A loss of about 30 degrees F occurs as a consequence of the immersion in the dip tank 26 from whence the winding is quickly transferred to and put on the next conveyor for progression through the drying and subsequent sections.

In the dip tank the varnish is held substantially to a constant composition and at a constant temperature of about 100 degrees F. in this illustration. Other types of varnish and compositions would require corresponding adjustments in the temperature and composition relations between the varnish and the temperature of the windings presented thereto. The windings as a consequence are efficiently and uniformly preheated, impregnated and dried resulting in a completely standardized specification product.

Although a preferred embodiment and practice of the invention have been described, it will be recognized that modifications thereof may be -made within the scope of the appended claims.

I claim:

1. Apparatus for preparing electrical windings for varnishing, comprising in combination, an endless belt flat bed conveyor, a drive for moving said conveyor in one direction in step by step fashion, an oven having a passage therethrough, said conveyor substantially constituting a moving oor for said oven, doors at the ends of said oven. synchronizing means for opening and closing said doors and moving said conveyor while said doors are substantially open, laterally directed interior orifices along at least one side of said oven, said orices being spaced apart substantially the same distance that said conveyor advances at each step, blower means for supplying heated air to said orifices, and means for heating said air to a predetermined temperature, whereby heated windings ready for further handling are successively presented at a substantially uniform temperature and condition by said conveyor.

2. Apparatus for preparing electrical windings for varnishing, comprising in combination, a at bed conveyor, a drive for moving said conveyor in one direction in step by step fashion, said steps being of equal length with equal time intervals between successive steps, an oven having a passage therethrough, said conveyor substantially constituting a moving oor for said oven and extending beyond the ends thereof, doors at the ends of said oven, synchronizing means for opening and closing said doors and substantially completing the movement of said conveyor while said doors are open, laterally directed interior orifices along at least one side of said oven, said orifices being spaced apart in a direction parallel to said conveyor substantially the same distance that said conveyor advances at each step, nozzles associated with said orifices for increasing the lateral direction thereof, means for supplying air to said orifices at a predetermined temperature and velocity, inlet and outlet ducts adjacent opposite ends of said oven, and means for circulating heated air through said ducts, whereby windings are successively and uniformly heated to a predetermined temperature by lateral and axial convection and then successively presented by said conveyor for further handling.

3. Apparatus for transporting and impregnat- -ing heated electrical windings with varnish, comprising in combination, a manipulator for handling said windings. a track on which said manpulator travels in rolling engagement, rack and pinion means for moving said manipulator along said track, a crosshead on said manipulator, an hydraulic cylinder to raise and lower said crosshead, a mandrel shaft carried in a bore in said crosshead in slidable engagement therewith and substantially transverse to said track, a spindle journaled in said shaft in rotatable engagement therewith, a chuck rigidly connected to the rearward end of said spindle, gripping members pivotally connected to said chuck and adapted to be jointly operated for gripping action by movement respectively toward and away from the axis of said spindle, means for rotating said spindle, and a dip tank adjacent said track within reach of said gripping members, whereby heated windings of different sizes and configurations positioned laterally of said track at one end may be picked up by said manipulator and transported to a dip tank for immersion to a predetermined radial distance from their outer periphery. rotated while so immersed and removed without substantial loss of heat due to atmospheric coolmg.

NATI-IANIEL B. ORNITZ.

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

UNITED STATES PATENTS Number Name Date 595,808 Goff Dec. 21, 1897 856,996 Custer etal June 11, 1907 877,037 Bernard Jan. 2l, 1908 1,274,830 Wood Aug. 6, 1918 1,314,889 Megan Sept. 2, 1919 1,689,062 Titchener Oct. 23, 1928 2,249,521 Graham et al July 15, 1941 2,334,854 Zademach Nov. 23, 1943 2,362,653 McGovern s Nov. 14, 1944 2,469,123 Martin May 3, 1949

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