US2394066A - Apparatus for coating wire - Google Patents

Description

Feb. 5, 1946. H. J. KAUTH APPARATUS FOR COATING WIRE` Filed sep. so, 1942 C V Sheets-Sheet 1 INVENTOR /L/f/v/Qv J Aim/TH TTORNY Per. 5, 1946.

H. J. KAUTH APPARATUS FOR GOATING WRE Filed sept'. so, 1942A s sheets;sneet 2 INVENTOR Feb. 5, 1946. v H. J. KAUTH 2,394,066

' APPARATUS FOR comme WIRE .Filed sept. so, 1942 5 Sheets-Sheet Patentedv Feb.- 5, y19,46A

UNITE-D STATES PATENT or-'Flcs This invention relates to apparatus for coating wire, particularly with enamel. and has for an object the provision of improvements in this art. 1

The method of enameling wire which is com-A monly y employed throughout the industry at present consists in passing the wire a number of times around two sets of vertically spaced sheaves, the lower set being disposed in a pan of enamel; applying a coating of enamel to the wire each time it passes around a lower sheave; and baking the enamel in successive layers -as the wire passes vertically upward vfrom the lower sheaves through a baking oven to the upper sheaves.

it passes therearound to pick up a fresh coat ofl enamel. Even one or more previous layers may be softened during passage through the bath and injured by pressure from the sheaves.

And yet another disadvantage is that it is unhandy, untidy, unsanitary, and possibly un healthy to string up the wires in the conventional the enamel. .j .According to the present 1'5 There-are a number` of disadvantageslin the conventional method and apparatus.'

One disadvantage isthat the rotation of the lower sheaves in the bath of enamel draws air into the bath and reduces the quality of the enamel coating von the wire. When this trouble is suppressed by completely immersing the lower lsheaves in the bath, the large amount oi enamel required proves troublesome. The sheaves need to be relatively large to keep the wire immersed long enough to coat'it properly and to avoid bending` the wire too sharply.

Another disadvantage is that the large quanbut both sets of sheaves are-frun dry. l. e. tree apparatus. The operator is required to put his hands inthe enamel bath to thread the wire around the lower sheaves, and, in addition to soiling the hands, the enamel may injure them by reason of the harmful chemicals contained in is provided in which the;, wireis passed a number of times aroundtwosetsot spaced sheaves,

'jot enamel, and thefenamel is applied to the wire hands.

tity of enamel which must be maintained in the bath, often amounting to as much as fifty gal'- lons, constitutes a serious fire hazard. Certain components of the enamel are very volatile and inflammableand the-bath of` enamel is located under and near the baking oven.

Another disadvantage is that the vbath presentsl a large surface area` to contamination by air and loss by evaporation.

Another disadvantage is thatthe speed oi movement oi the wire is restricted because. if the lower sheaves 'rotate too rapidly, they will increase the turbulence. and air entrapment lin the 4bath of enamel. f

Another disadvantage is that vthe bathz of enamel normally becomes contaminated, as by metal dust or ilakes-from the base wire, and these particles of electricallyconductive material are likely to be lincorporated ineach layer of enameh'thus reducing theinsulating value oi the coating." With a large bath, itis not easy to filter out these harmful suspended particles before they become incorporated in the enamel coatingon the wire.. l

Another disadvantage is that the coatings of V enamel may be improperly applied due to presvsureoithe'lieaves onone naso:

on the straightfspans between sheaves as it ad vances .to the baking oven.

By this arrangement and by the use of a specially designed enamel applicator, c .the enumerated and other disadvantages of the prior practice are avoided. l

A construction in which both sets ofsheaves are run dry permits easyand rapid Stringing oi the wire and avoids soiling or injuring the The enamel applicator provided by this invention furnishes adequate length of contact for proper wetting and adhesion, but .requires only a very small amount of enamel-one .quart being als . lbeneath the oven; and. if a nre should develop, the amount of material is so small as to cause ns-Ifl entirely adequate-and reduces the enamel suriace exposed to air to a negligible area. The fire hazard is thus greatly reduced becausethere is not a large open pan with a heavy vapor output no `serious damage.

There is no mechanical contact at all between the wire and related parts while it is being coated and prior to baking; hence the layer is smooth and the previous layers-are vunin.1ur :11. Moreover, there are no factors which limit the speed of wire-travel, when high speeds are desired 'they may be. utilized.

'I'here is no'undue turbulencein jenwd vduring application; hence the entrapment of air in the enamel coatings is avoided.-

'Ihe enameldurlngapplication to the wire is caused to flow in a direction opposite to the di- ,rection'v oi' travel of the wire, and washes .the

dust from the base wirev at the lower portion'oi the applicator end allows the wire to pass through {rclhly enamel at it! lat invention, apparatus l f 'The Pille! i of contact with the'enamel. This provides posi. tivecliminationoi' any contamination of the enamel nlm by 4electrically conducting metal objects and advantages of the invention may be better understood. from the consideratiOn f an exemplary embodiment which is' shown in the accompanying drawings. wherein:

Fig. i is s side elevation and section, somewhat 7 vdiagraminatic'in nature. oi' enameling apparatus embodying the invention; l Fig. 2 is'a similar front elevation;

Fig. .3 is a front'elevation of theenamei applidevice; y

- is a verticalsection takenon the line f Fig. 3; and

5 is a s-s of ris. 4.

Referring to the sisi from a supply or pay-oil spoolfzt and passes in a plurality of free verticalstrands 2l between a lower set of sheaveszlgfand an upper set of sheaves 23, thence to atake-iup spool 24. A trav-V ersing device offanyfapproved type guides the `wire to the take'p spool. sheaves are dry-running, as distinguished from horizontal section talrenvon theflin'e' l drawings, ai-''w'lre is drawn' `ration esclude Hinge partly or 'wholly transparent to permit and slot connections-facilitate' rapid opening closing of-the cover. The covermay atl-any time .to permit inspectiom'br tion without opening i t. with this construction v thethreadingofthe-"inrets The applicatorl plate is suiiiclently long to per- `mit the strands to be adequately. wettedand coated. A length of from six to twelve inches has been found to work well for all normal conditions and speeds of wire. travel. The width oi the plateis adequate to 'embrace all stran yin' some instances. as forexample when the 'viscosity and vsurface ',tension of the enamel are low, this Wiper is not The wiper is preferably of the positively driven rollltype in which the roll 56 travels in the direction .of movement ofthe wire and picks up excess material 1 the conventional-apparatus in which the lower set runsimmers'ed in a pan of enamel.

- desired. This 'provides additional control of coating thickness and also a means of eliminati without contact'with the Preferably., also the roll runs faster than the -wire travels, but its speed is adiustable to suit lvarious conditions.

A scraper S58 may be employed for removing enamel from the roll and directing itto a return e pipe 51 leading to the wpa/Ehe Wiper 1S 9rdv vJustable in'po'sition solas tov be movednearer the applicator or nearer the oven. as mayj'be ing waviness of theLi'ilm when'the surface tensionof the enamel is high. The length ottime 83 between application of the enamel and applicasupply trough or manifold 34 having channel 4 with the direction of nowiof enamel on the plate.

ducts Il leadingto the upper yends of the vertical face grooves 33. vFor ilne sizes of wire no the wire strands when disposed therein.A '.l'he

lower end of the applicator plate is curved laterboth directions at once. However. thewire prefally away from the strands, as shown at I.. to

llead oi! excess enamel which does not adhere.

to the strands. A collection trough 4l takes-the;- excess material which runs oivthe bottom edge' of the plate.

A supply-pipe tzee'rries ehemerto the upper` trough and a return pipe 43 carries the-ex-f tion of heat to the enamel is important' in preventing waviness ofthe illm.

The' applicatoroperates satisfactorily for either direction of wire movement. elther against or This permits the use of the applicator for strands entering the oven from either direction or from erably travels through the applicator ine. direction opposite to the direction ot flowof enamel therethrough, as described hereinabove. in order that the freshly coated'strand may emerge-from clean enamel, and that all 'metalfdun infinie fresh coat is avoided.

It is thus seen thatthe'present apparatu'sprovides animprovement in vthe application of .enamel to wires` which avoids afgreat many of the serioueobieetions to enst-ing practices. and in auf.

cess enamel to la reservoir or sump 44 'of a pump u. The pumpis preferably disposed within the sump M and the lattenis removablefor reillling. Thesump'may' be of any desired size but' preferably isfof small' capacity, say about'a quart, it being a-feature :o f this invention th a t the apparatus may be. operated satisfactorily dition provide advantages in speed, sai-'emana saniv 'tary'conditions which could-notb'e! 'attained -mldrtheexisting practices. The novel m cation tiled Whilev onei -;tne inventionl'hss stood that the invention-my variously 'emenamel may befkept=tf-any desired temperature v by pplopriatem'ean's, such as aheater at the sump or a heaterIi-on the back M the ppm otorplate.. Y

and' It' preferably have. flexible' sections 'orioints at the applicatorf plate to permit thelatter to'jbe'swung on-fits'v hinges' Il. ,when the strehqe-heve-beeh properly'positioned adjacent the applicator plate. fthe exposed 'side eiosea by o eaves-n tolxep'aownfevspo- 75 bodied within thelimlts'fof theprior the scope otthe subiolnedclaimsf I'claim as inyinvention;

1. Wire coating @pointuscomprising lr eombination, aplate provided with a .f'shllow open menthe wire tobecoated, means for supplying iiquid 'coating-material storie ehu or the rossore vtiovv to thefothe'r end, means for moving a wire ei'rione face vthereof larger .throughlthe-coatlng'lmaterial in the 'passage to' 'wire'.v and`means' for hardening the coatlng on the wire.

2. wiretoetinc n bol and herein .is the subject matter o! aI nu bination, aplate having in one face thereof a plurality of vertically disposed open longitudinal passages larger than the wire to be coated, said passages being fdeiined solely by the said plate,

means for supplying liquid coating material to the upper ends of the'passages to ow downward to the lower ends, means for moving a plurality of wire strands through the.. coating material in said passages to. coat the strands, and means forv hardening the coating material on'the wire.

3; Wire coating apparatus comprising in combination, spaced sheaves supporting a wire strand freely between them, means for applying an excess of a coating oi.' liquid material tosaid free strand as it travels between the sheaves in such manner that the strand moves out of the coatgroove for supplying coating material to the up- -per end thereof, said plate .being curved away from the path of the wire strands at its lower end to draw off excess coating material which does not adhere to the wire strands as a coating zone through freshclean materialwhereby l the coat on the wire is kept free from metal dust or the like which may be accumulated in the ma;l terial from the wire, means for withdrawing the:

excess coating material from the wire,.meansJ for continuously filtering the excess coatingl material which carries the suspended metal dust and returning it tothe coating zone, and means for hardening the coating'material von the stran between sheaves. Af 4. Wire coating apparatus comprising in combination, upper and lower sets of` sheaves-.supporting a plurality of upwardly moving wire strands freely' between them, av plate provided ing, and means to remove' and return the excess coating material to the manifold.

'7. Wire coating apparatus vcomprising in combination, upper and lower sets of dry-running sheaves supporting a plurality o1, V.wire strands- I freely between them, an applicator'plate mounted adjacent said strands by 'a hinge connection permitting it to be swung away from the strands, said plate being provided with a plurality of oversized vertical grooves, a trough. at rthe upper end of.' said plate provided with holes leading toeach 25;'fverti'cal groove to supply coating material thereto, a supply pipe for said troughi at the hinge line of the plate, said plate being curved away from :the strands at its 'lowerend to draw oil excess with a like number oilshall'owv vertical grooves' larger than the wire in which said strands move, means for supplyingicating material to the'upper Vends o! the grooves in excess of that Awhich the wires will take as a coatingmeans for removing from the lower ends of the grooves the excess coating material which is not taken' up by the strands. and means for hardening the coating material on the strands before they reach the upper sheaves. I y .f I Y i 5. Wire coating apparatus comprising an yapplicator plate provided inl one facethereof with a shallow strand groove larger than the wire. one

endof said 'groove being higher than the other 'coating material, a trough to receive said excess coating material, a cover for enclosing said strands when in saidgrooves, a wiper roll near the strands .running in the direction of their movement for v removing excess Icoating material adhering to saidstrands, meansdor removing and -.col1ecting excess coating material from said roll,

- an oven' for baking the remaining coating on said` tree strands, means or returning' al1 excess coating material to a sump, a pump 'for forcing coating materialback to the upper trough, means including a cup embracing the pump for supplying make-up coating material to the system, and

end, a trough for supplying coating material to 5 the upper end o! `said groove, said plate being a filter inthe circulatorysystem for continuous'- ly cleaning A turned to the upper trough.

the coating material before it is ref imNnY l

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