US2260860A - Apparatus for handling strands - Google Patents

Description

och 1941- E; EQNEWTON ETI'AL APPARATUS FOR HANDLING STRANDS Original Filed May- 21, 1938 3 Sheets-Sheet 1 ll/ll I.M\ Wk V I l r s N r r w -|ldl R OEL R 0 TH E 0 w 7 V r N T w E 5 E A WNP Mu Q I A R 5..., e. V 8 nfii m it 3 \l.... T "111%: TI an I: L: R if a i n 3313333 a n .::::::I ll ECEEECE J Cd. 28, 1941. E. E. NEWTON ETAL 5 APPARATUS FOR HANDLING STRANDS original FiledMay 21, 1938 5 Sheets-Sheet 2 e 74 7k 7s FIG. 4-

v INVENI'ORS E E. NEWTON C A PEACHE'V F. RJPEEVA'U' ATTORNEY 1941- E. E. NEWTON r-rrm.

APPARATUS FOR HANDLING STRANDS Original Filed May 21, 1938 3 Sheets-Sheet 3 INVENI'ORS 5.5. NEWTON C-A. PEA CHE) FIR. REEVELY ITTORNEY fron.

Patented Oct. 28, 1941 1,260,860 APPARATUS FOR HANDLING STRANDS Edwin E. Newton, Montreal. Quebec, Cyril A. Peachey, Ville La Salle, Quebec, and Frederick R. Beevely, St. Lambert, Quebec, Canada, assignors to Western Electric Company, Incorporated, New York, N. Y., a' corporation of New York Original application MayZl, 1938, Serial No;

Divided and this application September- 15, 1939, Serial No. 295,024:

4 Claims. ((11. 91-55) This invention relates to an apparatus for han dling strands, and more particularly to an apparatus for coating strands, especially electrical conductors, with viscous liquid or plastically pasty materials.

Insulating sheathings on electrical conductors are made, at the present time, in a multitude of ways, some of which include th application to a bare or previously variously sheathed strand of hardenablematerials applied in liquid, semiliquid, or pasty form and subsequently hardened. Thus materials in the nature of paint, enamel, varnish, or waxes, asphalts, parafllns and the like dissolved in volatile vehicles, artificial resins hardenable by polymerization induced by heat, and other analogous materials are used for one or another specific purpose. In many such instances a solvent or vehicle is used which is volatilized to be subsequently recovered; and a considerable part oithe cost of the coating operation may arise out of the volume of material to be recovered for subsequent re-use. Hence it is desirable and may be vitally important to apply the raw sheathing or sheath treating ma- ,terial in a condition approaching dryness as nearly as may be practicable, i. e. as a liquid of high viscosity or even a smoothly plastic paste, in order that the volume of vehicle or solvent circulated in the process, or perhaps wasted, may be kept low.

An object of the present invention is to provide an apparatus simple, rapid and reliable in operation, for forming and hardening a coating of material, such as described above upon a strand, in which the material may be of a viscous or stiflly liquid nature or even a plastic paste, and in which the material may be applied thickly and yet hardened uniformly.

With the above and other objectsin view, the invention in one form may be embodied in an apparatus comprising an applicator head with a chamber having a strand inlet member and a wiping die strand outlet member, and means to supply coating material in viscous or pasty form under pressure to the chamber, together with means to subject the coated strand emerging from the chamber to be preliminarily dried or hardened at room temperature and subsequently subjected to being dried at a suitable elevated temperature, thus to avoidformation at once upon the raw sheath of an outer skin which wou retard or even prevent escape of vehicle he inner layers. a 0 her objects and features of the invention will appear from the following detailed description of one embodiment thereof in an apparatus for applying a viscous mixture of cellulose acetate in an acetone vehicle to a textile covered electrical conductor strand, taken in connection with the accompanying drawings in which the same reference numerals are applied to identical parts in the several figures and in which- Fig. 1 is a view in side elevation of the apparatus with a portion of. one wall broken away;

Fig. 2 is a view of the apparatus in plan;

Fig. 3 is a. sectional view on the'line 3-3 of F g. 1;

'- Fig. 4 is a diagram of the path of a strand. through the apparatus;

Fig. 5 is an enlarged detached view partly in section of a prelerred form of one of the twin material applicator heads;

Fig- 6 is a similar view of a. applicator head;

Fig. 7 is a fragmentary view similar to Fig. 1 of a modified form of apparatus;

Fig. 8 is an enlarged detached view in section of the die of Fig. 5;

Fig. 9 is a similar end view thereof;

Fig. 10 is an enlarged view in side elevation of the pressure rolls at the right hand end of Fig.

Fig. 11 is a similar view thereof in .end elevation;

Fig. 12 is a similar view thereof in plan; and

Fig. 13 is a further enlarged, partial sectional view of the contact of two of the pressure rolls of Fig. 11. v

The apparatus herein disclosed comprises, roughly, means to apply a viscous or pasty material to a strand combined with means to harden the applied material on the strand, the two being so constructed and arranged that the process modified form of of hardening begins immediately the coating is applied with a step of preliminarily hardening at room temperature and subsequent further treatment at an elevated temperature.

The heart of the paste applying means is a twin applicator device best shown in Fig. 5 and tends taperingly into the chamber as at 28. Another plug 21. (Fig. 5) or I21 (Fig. 6) is mounted in the front wall of the chamber and has housed completely therein a wiper die member 28. This member 28 is a body of soft vulcanized rubber or similar material and is given any convenient shape. The particular member 28 illustrated is an ordinary soft rubber bottle stopper of suitable size. The plug 21 or I21 is recessed to receive and support member 28 which is held in place in the plug by any suitable means such as the removable retainer 38. The plug 21 or I21- and retainer 38 are axially bored to pass the strand IS with liberal clearance for both the strand and its raw coating. The die member 28 is formed with an axial bore of such size as to pass the strand l9 bearing a raw coating of predetermined desired thickness; and the meme ber 28 acts to wipe off any superfluous thickness of coating.

The above description of the applicator applies equally to the showing of either Fig. 5 or Fig. 6 and is completely descriptive of the structure disclosed in Fig. 6, in which the recess of the plug I2! is of the same shape as the member 28. The plug 21 in Fig. 5 is originally made identically like the plug I21, but the walls of the recess therein are modified by having flutings or grooves 29 formed longitudinally therein.

The structure and function of these applicators per se and apart from their general combination in the structure and function oi. the apparatus as a whole are no part of the present invention, being disclosed and claimed in copending application Serial No. 209,395, filed May 21, 1938, by one of the present inventors. Also the process for the carrying on of which the present invention was made, is no part of the present invention, being disclosed and claimed in copending application Serial No. 209,396, filed May 21, 1938, by the present inventors and of which application the present application isa division.

An object of this arrangement is to permit the coating material under pressure to have access to the exterior of the soft member 28 to insure a uniform wiping effect.

The twin applicators 28 may conveniently be supported, as shown, upon the upper end of a vertical feed pipe 31 which serves to bring coating material to the chambers 22 as well as to support the twin applicators. A valve 32 mounted in the feed pipe serves to control the flow of coating material from a supply tank 33 through the pipe to the applicators. A supply of some inert gas, nitrogen, carbon dioxide or other similar gas according to the nature of the coating material, under pressure is fed into the upper part of the tank 33, preferably above the level of the coating material therein, through a pipe 34 from a suitable supply 35 of the compressed gas. If desired an indicating-pressure gage 38 may be mounted at any convenient place and connected by a pipe 31 to the pipe 34. For many materials, coating material supply means as thus far described is satisfactory. For others it may be desirable to provide agitating means such as a stirrer 38. As such devicesare familiar in many suitable forms and their structure and operation are irrelevant to the present invention, no further.description is deemed necessary here. Such an arrangement will also enable the material to be compounded directly in thetank 33 if desired.

Immediately behind the pipe 3| and its sup ported applicators 28 is the entrance to the sheath hardening section of the apparatus. This comprises fundamentally a series of three horizontal, elongated chambers, positioned for convenience one above the other. The first, uppermost chamber 48 opens at its forward end directly opposite to and immediately behind the outlets of the two wiper dies 28 and their re- ;tainers 38. The rear end of the chamber 48 opens into a short vertical passageway 4| within which are mounted two coaxially spaced guide sheaves 43 and 44, over which coated strand from the applicators 28 after passing through the chamber .48 passes down and around another pair of guide sheaves 45 and 48 located in the lower portion of the passage 4|. The chamber 48 is laterally completely enclosed, but its forward end is open to the outer air, and its rear end is completely open into the passageway 4| and so to the open air, since the passageway 4| has no wall on the side toward the beholder in Fig. 1. Air is drawn from the chamber 48, at some point between its ends, bya blower 4'I driven by a motor 48 and is exhausted through a pipe 48, preferably to some solvent recovery means not shown. Fresh air at room temperature then enters the chamber through its open ends.

The second, intermediate chamber 58, may be located most conveniently immediately below and parallel to the chamber 48. The chamber 58 is preferably substantially completely enclosed on all four sides and both ends, except for apertures in its floor near .each end communicating with the chamber 88 below. As these apertures are merely means for air to be circulated as later described from the heated chamber 88 through the chamber 58, and hence their size and shape are not material, there appears to be no need to describe them more in detail. The rear end wall next to the sheaves 45 and 48 is provided with small apertures, preferably barely large enough to allow strand from the sheaves 45 and 48 to pass through without harmful friction and enter the chamber 58.

Multi-grooved strand guide rollers 5| and 52 are positioned transversely across the chamber 58 near its respective ends, and strand entering the chamber from the sheaves 48 and 48 passes in a plurality of continuous loops over these rollers as hereinafter described. "he forward end wall of the chamber 58 hasa small aperture to allow the strand, at one point in it; travel, to pass out of the chamber and over a gun sheave I3 into one of the applicators 28. Te floor of the chamber 58 is also perforated at one place to allow the strand to pass out of the chamber there and to a take-up mechanism to be de-- scribed later.

A long baille 53, running lengthwise of the chamber 58 from near the rear side of the roller 5| to near the forward side of the roller 52, divides the chamber-over most of its length into parallel, upper and lower passageways through which the coated strand may pass to and fro between the rollers SI and 52.

. venient source not shown, is located in this chamber to heat a current of air or other drying medium passing thereover through the chamber so. as may be drawn into the chamber "at one end from the chamber 50 and forced into the chamber 50 at its other end by any suitable means such as a blower fan 62 driven by a motor 63. This circulating air is then warmed by the elements II. A proportion of the air thus circuwould be the case if an equally o equivalently lated may be bled of! through a pipe 64, which Y may conveniently communicate with the pipe 48'.

In the apparatus disclosed the air thus lost is replaced by leakage into the chamber through the various small apertures noted and also through the unsealed joints of its walls, although, if desired, an appropriate aperture may be provided for this purpose.

Strand to be coated is drawn from a supply reel III over a tensioning roller II' and a guide sheave l2 and passes thence through the farthat (Fig. 1) of the twin applicators 20. In the chamber 22 of the applicator, the strand passes through amass of viscously liquid or plastically pasty coating material supplied to the chamber from the tank 33 under pressure provided by g the compressed gas in the supply 35. The pres-,

sure of the material in the chamber 22 is con-' trolled by the valve 32. How far the process of coating by which the strand emerges from the applicator with a sheath of raw coating material,

may be termed an extrusion process or how far it is merely a matter of adhesion of the coating material to the strand it is diiilcult to say. The pressure is ordinarily held at such a point that,

in spite of the form of the nose 26 and of the drag of the strand through the bore 25, a certain amount ofthe coating material is forced out through the bore and accumulates on the front face of the plug 24, to be periodically removed. At the same time the pressure is held below the point at which the coating material would be forced through the bore of the member 28 in excess of the amount desired as a coating on the strand.

thick coating of the customary thiz 'liquid preparation were used and it were attem zed to harden it to the same consistency by heated air. I

From the sheave 43, the strand passes under the sheave l5 and thence into the chamberthrough which it passes without ontact with any solid object until it passes up over the roller 5|. Thence it travels to and fro in 2e chamber Bl around the rollers II and 52 such a number of times as is found to be necessary or desirable to harden the coating to the intended c egree. The strand then passes out of the chamter 50 at its front end, over the sheave I3 and ihrough the second applicator 20 .(the. nearest or a in Fig. 1) wliiere a second coating of pasty ma erial is appl ed.

In passing around the rollers 5i a1 :1 52 as described, the partly dried or hardened coat has its remaining volatile matter driven cut and removed by the hot air circulated through the dryterior. Hence when the strand emerges from they chamber 50 it has a relatively thick uniform sheath which is substantially dry of solvent throughout its thickness.

The strand then passes through the second applicator, as already described, and the new sheath is dried in the same manner as the first one, the strand passing through the chamber 40,

The raw coated strand leaving this first applicator 20 passes, without contact with any solid object until it reaches the sheave l3, through the cool drying or hardening chamber 40. During this passage a considerable proportion of the volatile .vehicle or solvent in the raw coat is removed by evaporation at the-relatively low temperature in this chamber, without the formation on the coat of a relatively dry superficial skin to retard subsequent removal of residual volatile matter. By the time the strand reaches the sheave 43, the partly'dried sheath has become hard enoughthroughout its thickness to endure being carried around the sheavewithout damage.

Because of the fact that the coating material is thus applied as a relatively thick paste with no i tioned a guide sheave I4. the strand passes over a tension roller I5 and great volume 01. solvent or vehicle, this first coat may be applied in a thickness several times as great as is practicable where the strand is simply passed through a relatively thin liquid bath of raw material. Also it becomes practicable to give this relatively-thick coating suflicient hardness to endure contact with a guide sheave in" the cold preliminary chamber 40 within a reaonable and practicable distance between the applicator and the sheave 43. At the same time, since this is done at relatively low temperature, solvent or vehicle isv removed from the raw sheath substantially throughout its thickness and without the formation of a dry, tough and impervious skin over a still soft interior, which might slip, tear and wrinkle on the strand if it were passed over a sheave, capstan or the like, as

around the sheaves 44 and 46, into the chamber 50 and back and forth around the. rollers 5i and 52. This time the strand emerges from the chamber 50 through the perforation or aperture in its floor, noted above and in which is posi- From this latter sheave thence to a take-up reel 16.

The take-up reel I6 and the roller 52 are both driven by any suitable means, such as the belts indicated in Figs. 1 and 2, from a motor 11.

The roller 52, being driven as described, acts as a capstan to assist in advancingthe strand through the apparatus in addition to the effect of the take-up reel I8. For this reason, the diameter of the roller 52 may preferably be made suiliciently smaller where the first passes of the strand run than where the later passes run to compensate for the sometimes unavoidable elongation of the strand due to the tension needed to advance the strand. For the same reason it may be preferable also to taper the roller 5| correspondingly or even in some cases to replace the roller Si by a plurality of independently rotatable guide sheaves.

The drying eflectiveness of the chamber 40 is dependent partly upon the room temperature speed. In some cases it may be desirabl and even necessary to close even the small gap between the applicators 20 andv the open end of the chamber 40 as shown in Fig. 7, where the ally completely chamber 40 is extended to substantially enclose and contain the twin applicators.

While the apparatus and procedure as thus far described'may be substantiallyentirely satisfactory with some materials and for some purposes, in some instances it may be desirable to effect a greater degree of compactness and smoothness in the applied coating, especially where a porous sheath, e. g. of textile or paper pulp material, on the strand is to be both impregnated and coated. In such a case, means are provided at theend of the first pass of the. strand, through the chamber 40, to compact and smooth the coating.

As herein disclosed, particularly in Figs. to 13 inclusive, such means may comprise a presheat hardenable coating material having no volatilizable material is applied to-a strand, is then aged for a predetermined time at room temperature, and is then hardened at an elevated temperature.

Many such materials in'the raw state comprise ammonia or substance which gives ofl. ammonia.

In such cases the air circulating and supplying means of the apparatus as disclosed may be a coating several or even many times as thick as sure sheave or roller 30 mounted to ride on top of the strand passing overthe topof the sheave cumference oi the strand and leave room over small portions for excess material. I a

A forming sheave, or roller '3 is mounted to be freely rotatable-in a fixed position a little below sheave 43, with its periphery tangent to the path of the strand" from the sheave 43 to the sheave 45, and with its plane at right angles to the common plane or the sheaves .43 and 4L A c'oacting pressure sheave-or roller 84 is mount-' ed, on the other side of the strand I, to be free ly rotatable in a-Ireely pivotable arm 85 supported in any suitable manner on the apparae .latterare shown in Fig. 13.

tus, and a tension spring .6. The peripheries of the sheaves 43 and 84 are grooved in the same manner as'those oi the sheaves 8| and 4; as the Since the contact line of thesheaves SI and 43 passes through the axis of the strand ina diretcion at right-angles to that of the contact line or th sheaves." and 84, the strand is formed and compacted over the that-which may be applied where the raw coating material is in the frequently customary form of a relatively thin and liquid solution. In some instances a satisiactorycoating may be produced with a single applicator, the strand being brought out over the sheave 14 after its first drying instead of being brought out over the sheave I3 to the second applicator, and such coating, in the case of cellulose acetate with an acetone vehicle, may be as thick as one requiring six or. more several applications of a truly liquid solu- 1 I tion. I

. It may be noted here that it may be desirable in some instancesto use an'inert gas,- e.' g. nitrogen, carbon dioxide, helium or the like as a volatilizing' agent. In such case the several chambets, modified as shown in Fig. 6. will be made substantially gas tight, and gas to replace that bled oil or carried oil through the pipe .4 will be replaced bygas supplied from the solvent recovery means or any suitable source and intro I proaches complete dryness may be controlled by the temperature in the chamber 50 produced by entire circumference of the applied coating by passing successively through the two pairs of coactin'g rollers.

If it be found desirable, a second set or forming rollers may be similarly associated with the sheaves 44 and 46.

Substantially the same process and apparatus may also be used where the coating material is a preparation in the raw or more or less unpolymerized state of one of the polymerizable oils or artificial resins, e. g. comprising China-wood oil either raw or partly polymerizedor one of the many forms or an aldehyde polymerized or condensed with a phenol type compound. In such a case the hardening of the material results primarily from an atomic or molecular rearrangement'of the substance of the material.

It is found, in some instances of such products, that what maybe termed'an aging step of allowing the material, after being applied and before being I heated to induce, hardening, to rest at room temperature in its finally desired physical the heating elements 6|, or by the total length or the path of the strand inside the chamber 50 or by both.

Sinceit is possible by this method and by such apparatus to employ a thick plastic paste instead of a relatively thin liquid form for the coating material, it is evident that the invention has the further important practical advantage of producing a markedly smaller volume of volatilized vehicle vapors to be treated to recover the vehicle for re-use.

The embodiment of the invention disclosed may clearly be modified and departed from in various ways without departing from the spirit and scope of the invention as defined in and limited solely by the appended claims.

' What is claimed is:

1. An apparatus for coating strands which apparatus comprises an applicator having a chamber through which a strand to be coated may pass, means to supply highly viscous pasty coating material, comprising asolid and r'a solvent,

to the chamber and to maintain the aterial in the chamberunder pressure, means in the chamber to control the thickness of the coating of material on the strand emerging from the chamber, in combination with coating treating means having a first treating chamber through which the raw coated strand passes from the appli--' cator chamber, said treating chamber being of sufiicient length to evaporate a major portion of the solvent, means topass a gaseous treating medium through the first treating chamber at room temperature, a second treating chamber through which the coated strand passes from the first treating chamber, and means to pass a gaseous treating medium through the second treating chamber at a raised temperature, the said second 'treating chamber being of suflicient length to harden the coating.

2. An apparatus for coating strands which apparatus comprises an applicator having a chamber through which a strand to be coated may pass, means to supply highly viscous pasty coating material, comprising a solid and a solvent, to .the chamber and to maintain the material in the chamber under pressm'e, means in the chamber to control the thickness or the coating of material on the strand emerging from the chamber, in combination with coating treating means having a first treating chamber through which the raw coated strand passes from the applicator chamber, said treating chamber being of sumcientlength to evaporate a major portion of the solvent, means to pass a gaseous treating medium through the first treating chamber at room temperature, means to receive the treated strand from the first treating chamber and to compact the coating by pressure, a second treating chamber through which the coated strand passes from the compacting means, and means to pass a gaseous treating medium through the second treating chamber at a raised temperature, the said second treating chamber being of suficient length to harden the coating.

3. In an apparatus for coating strands with highly viscous plastic material, comprising a solid and a solvent, and having means to apply a relatively thick coating of such material to a v strand, coating treating means having a first treating chamber through which the raw coated strand passes from the applicator means, said treating chamber being of sufiicient length, to evaporate a major portion of the solvent, means to pass a gaseous treating medium through the first treating chamber at room,temperature, a second treating chamber through which the coated strand passes from the first treating chamber, and means to pass a gaseous treating medium through the second treating chamber at.

evaporate a major portion of the solvent, means to pass a gaseous treating medium through the first treating chamber at room temperature,

means to receive the treated'strand from the first treating chamber and to compact the coating by pressure, a secondtreating chamber. through which the coated strand passes from the compacting means, and means to pass a gaseous treating medium through the second treating chamber at a raised temperature, the said second treating chamber being of suflicient length to harden the coating.

EWIN E. NEWTON. CYRIL A. PEACHEY. Y FREDERICK R. REEVELY.

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