US2048886A - Insulated conductor and method and means for producing same - Google Patents

Description

J. w. OLSON July 28, 1935,

INSULATED CONDUCTOR AND METHOD AND MEANS FOR PRODUCING SAME Filed Nov. 14, 19,35 2 Sheets-Sheet 1 fo/v/v OLSO/V.

ATTORNEY! J. W. OLSON July 28, 1936.

INSULATED CONDUCTOR AND METHOD AND MEANS FOR PRODUCING SAME Filed Nov. 14, 1935 2 Sheets-Sheet 2 INVENTOR. k/OH/V W Owe/v ATTORNEYS Patented July 28, 1936 UNITED STATES I 2.048.888 msum'rsnconnuc'roa AND mrrnon AND MEAN S FOB.

John W. Olson,

PRODUCING SAME Hastings-upon-Hudson, N. Y., as-

signor to Anaconda Wire & Cable Company,

New York. N. Y.,

a corporation of Delaware Application November 14, 1935, Serial No. 49,689

8Clalms.

This invention relates to electric conductors of the type referred to by those skilled in the art as weatherproof wireand to certain improvements in method and means of producing the same. The

5 improved method contemplates advancing a bare conductor, such as a single wire or stranded wires while completely enclosing it in a very loosely fitting jacket of fibrous material, such as one or more overlapping strips of paper, while twisting 10 the fibrous covering in a manner which will tight-' ly enclose the conductor and in finally forming an exterior covering of interconnected strands or threads over the fibrous jacket to complete the assembly.

The invention also comprises a novel combination of interdependent cooperating parts hereinafter more fully described in detail for carrying out the method disclosed. The accompanying drawings illustrate improved method, apparatus 20 and the resulting improved product.

In the drawings- Fig. 1 is a. side elevation illustrating the improved mechanism for carrying out the method; Fig. 2 is a detail of a portion of the assembly 5 shown in Fig. 1; Fig. 3 is a detail of a guide plate suitable for use in the assembly shown inFig. 1; Fig. 4 illustrates a second form of guide plate; Fig. 5 shows a third variation of the same plate; Fig: 6 discloses a fourth design for the guide 30 plate; Fig. 7 is an elevation of the folding tube;

Fig. 8 is a top view of the folding tube; Fig. 9 illustrates the finished product.

Referring in detail to the drawings, l represents a reel carrying a supply of wire 2 which is to 35 be covered. Movement of the wire may be secured by a capstan 3 mounted, in this case,- in an over-' head position on the axle 5. The covered conductor is taken up on the reel 4. When, paper is to ,be used as thefibrous covering, it is most conveniently supplied in the form of rolls 6, which are mounted on appropriate brackets 1 so that the material can be drawn ofi' as needed. In order to prevent the supply of paper from unrolling more rapidly than it is needed, brakes 8 bearing on the 45 outer surfaces of the rolls may be provided to retard their motion.

After leaving the rolls, the paper is drawn through the guide'plate 9 which is arranged to bring the strips in proper position relative to one 50 another as well as to bend the material prior to thetime it passes through the folding tube in. The form of the guide plate will vary according to the number of p p r strips employed, and to a large extent, the advantages of this method are 55 bound up in this number and its design.

In the preferred form, two strips of fibrous mav terial are used. This gives the degree of flexibility necessary if the covering is to be distorted without rupture. A plate 90. is illustrated in Fig.

i 3 and the large degree of overlap secured by this arrangement may be clearly seen by the position of the slots 22 through which the strips are fed. For example, it the strips used are each four inches in width, the overlap at each end should be approximately two inches. It is not essential that the opposite edges of a strip be either adjacent to the conductor or directly under the braid, as a plate of slightly different design 9b may be made up as illustrated in Fig. 4. This method of application is not limited to two strips, however, as the plate 90 shown in Fig. will accommodate a single strip, if this is desired. Or a plate 9d shown in Fig. 6 may be used, if three strips are employed. It will, of course, be understood that appropriate variations will be made in the number of rolls and roll carriers depending on the number of strips employed. v

After having been positioned by the guide plate, the strips pass to the folding tube III. This member serves two purposes, first it flattens the large tube of paper into a single plane so that it is ready for twisting and secondly, it maintains the conductor or wire in the center of the paper so that the covering of paper will be substantially equal on all sides, while retaining a maximum degree of overlap. The form of the folding tube is illustrated in Fig. 7 and it will be seen of the tube along the center line has been flared out to form an enclosed section II designed for the accommodation of the wire. This construction, which maintains the position of the wire in the center of the paper is clearly illustrated by Fig. 8, which is a top plan view of the tube.

A smoothing die I2 presses the paper into a uniform circular cross-section as the wire and paper are advanced through it.

A snug fit between the paper jacket and the conductor is secured by rotatingthe entire paper supply assembly comprising the supply rolls 6, the guide plate 9, the folding tube in and the smoothing die l2. By this operation, the paper is drawn down upon the wire and not merely pressed into 'position. So that the assembly may be freely romounted on a turntable H which rotates upon a ball bearing l5. Any appropriate motor or other source of power may be used to actuate the mechanism for application of tated, the base I3 is the paper, for example, through the medium of a belt l6 or through suitable gearing to the braider drive.

The braiding mechanism is of conventional design and the usual essential parts, such as carriers ll, spools l8, and horn gears l9 will be recognized in the drawings. The braided cover is formed from a multiplicity of strands 2| and serves to retain the fibrous jacket inplace both while in service and during subsequent handling consequent to manufacture and installation.

The mechanism described is peculiarly well suited for carrying out my improved method of that a portion incorporating the fibrous material about the conductor as the latter is advanced. From the detailed disclosure, it will be apparent that as the conductor is advanced longitudinally, the strips of fibrous material, such as paper or the like are fed in a generally longitudinal direction, that is in the same direction as that in which the conductor to be covered is advancing. The thus 1on gitudinally advancing strips are flexed transversely of their width and are positioned relatively to one another in an overlapping relationship. At the same time, these strips are being rotated with respect to the advancing conductor and the net result of this flexing, overlapping, advancing and rotating motion is to simultaneously crumple and interconnect the plurality oi. fibrous strips while at the same time twisting and compacting them around the conductor.

The resultant product of this method, therefore, comprises a conductor, either solid or stranded, a layer of closely fitting fibrous material helically twisted about the axis of the conductor and an outer-jacket oi braided strands or threads. The arrangement of the component parts is illustrated in Fig. 9, inwhich the conductor 2, twisted fibrous insulation 23 and braid 20 are indicated.

up in the form of a strip is adaptable to the purposes of this invention. Felt or fabric may be mentioned by way of illustration.

The use of paper as the body of insulation has been suggested prior to this time, but in all cases the material has been applied as a relatively narrow strip wound about the conductor. As compared with the product of this invention, the paper applied in the old manner lacks flexibility and presents a relatively short path to the conductor between openings in the solid dielectric even when a considerable degree of overlap has been employed between successive layers.

Furthermore, while a decrease in the width of strip employed will increase the flexibility oi the cover, the length of path through openings is correspondingly shortened. Conversely, higher dielectric strength is gained only at the expense of flexibility.

As comparedto an insulating covering which comprises a substantially uncompacted bulky filler such as cotton sliver under a braid, the method herein described offers two distinct advantages, namely, a marked increase in the dielectric value of the material immediately surrounding the conductor and secondly, the assurance that the conductor will be surrounded by a concentric layer of insulation. The latter condition is extremely diflicult to achieve when the fillers possess only a slight degree of mechanicalstrength, or are applied with little or no overlap by conventional methods.

While I have described quite precisely the preferred construction of the improved conductor and the steps followed in its method of produc tion as well as celtain specific'means for carrying out the method steps, it is to be understood that the drawings and description are to be interpreted in an illustrative rather than a limiting sense since various modifications may be made within the spirit and scope of the invention em-. 6 braced by the appended claims.

What I claim is:

i. In the manufacture 0! electric conductors. the method which comprises advancing the conductor in the direction 0! its longitudinal axis, si- 10 multaneously feeding a plurality of strips in the general direction 0! the advancing conductor while bending each of the strips individually around the conductor and positiomng them in overlapping relationship to one another and dur- 15 ing such bending of the strips rotating them about the axis oi. the advancing conductor so as to crumple or twist the overlapped strips around the conductor.

' 2. In the manufacture of electric conductors, the method which comprises advancing the conductor in the direction of its longitudinal axis. simultaneously feeding a plurality of strips in the general direction of the .advancing conductor while bending each of the strips individually 25 around the conductor and positioning them in overlapping relationship to one another and during such bending of the strips rotating them about the axis or the advancing conductor so as to crumple or twist the overlappedstrips around so the conductor and forming an outer covering of interconnected thread-like strands about such twisted strips.

' 3. An article of manufacture substantially as described comprising a conducting wire enclosed in a covering including a plurality of nested U shaped strips or fibrous material which progress helically aroundthe wire.

4. An article-of manufacture substantially as described comprising a conducting wire enclosed 40 in a covering including a plurality of nested U- shaped strips 0! fibrous material which progress helically around the wire and a Jacket 0! interconnected textiie strands embracing the nated strips.

, 5. An article oi'manuiacture comprising a conducting wire enclosed in a layer of insulation comprising a plurality of fibrous strips each having longitudinal iolds, said strips being disposed in interlocking nested relation and being helically twisted together around the conductor wire.

6. An article of manufacture comprising a conducting wire enclosed in a layer of insulation comprising a plurality or fibrous strips each having longitudinal folds, said strips being disposed in interlocking nested relation and being helically twisted together around the conductor wire and a jacket of interconnected textile strands embracing the assemblage.

John W. onsou. 5-?

Images