CN113646852B - Low cost extrudable separator made from slit tape - Google Patents

Abstract

A dielectric isolator for twisted pair cables includes a body formed as an elongated strip having a top surface, a bottom surface, a first side edge, and a second side edge. A first groove is formed in the first side edge and extends at least half way toward the center of the isolator. A second groove is formed in the second side edge and extends at least half way toward the center of the isolator. During the manufacture of the cable, the first wedge and the second wedge open the first and second grooves. The first twisted pair and the second twisted pair are inserted into the opened first slot and the second slot respectively. The third and fourth twisted pairs reside on the top and bottom surfaces respectively. Isolators offer the cost and reel storage savings of flat separator tape while providing the internal crosstalk performance of an isolator.

Description

Low-cost extrudable isolators made from slit tape

Technical field

The present invention relates to a twisted pair cable used for the communication of high speed signals, such as a local area network (LAN) cable. More particularly, the present invention relates to a twisted pair cable having an isolator between the twisted pairs within the cable, wherein the isolator separates each twisted pair from the other twisted pairs of the cable, and wherein the isolator is initially formed as a relatively flat member, such as a strip with slits in its thickness.

Background technique

With the massively increasing use of computers for homes and offices, there has developed a need for cables that can be used to connect peripheral equipment to computers and for connecting multiple computers and peripheral equipment into public networks. Today's computers and peripherals operate at ever-increasing data transfer rates. Accordingly, there is a continuing need to develop cables that can operate substantially error-free at higher bit rates by meeting various elevated operating performance standards, such as when the cables are used in high cable density applications such as , such as the reduction of internal and external crosstalk when routing next to other cables).

Figures 1 and 2 show a typical shielded twisted pair cable 1 and wires for four twisted pairs (first twisted pair A, second twisted pair B, third twisted pair C and fourth twisted pair The twisting scheme used in line D). Dielectric isolator 3 separates twisted pair A from twisted pairs B, C and D, twisted pair B from twisted pairs C and D, and also separates twisted pair C from twisted pair D. Separator 3 can also be thought of as a trough, star separator or plus sign separator.

Twisted pairs A, B, C and D may be twisted in combination with isolator 3 in the direction of arrow 5 (eg, opposite to the twisting direction of twisted pairs A, B, C and D) to form a stranded core. The stranded core is surrounded by a shield 7 . The shielding layer 7 may be formed of a conductive foil, and the edges of the foil may partially overlap at area 9 . The dielectric outer sheath 11 then surrounds the shielding layer 7 .

Each twisted pair A, B, C and D consists of two insulated conductors. Specifically, the first twisted pair A includes a first insulated conductor 13 and a second insulated conductor 15 . The second twisted pair B includes a third insulated conductor 17 and a fourth insulated conductor 19 . The third twisted pair C includes a fifth insulated conductor 21 and a sixth insulated conductor 23 . The fourth twisted pair D includes a seventh insulated conductor 25 and an eighth insulated conductor 27 .

Each twisted pair A, B, C, and D is formed by continuously twisting its two insulated conductors around each other. For the first twisted pair A, the first conductor 13 and the second conductor 15 are completely twisted to each other by three hundred and sixty degrees (a) at a first spacing w along the length of the cable 1 . For the second twisted pair B, the third conductor 17 and the fourth conductor 19 are completely twisted three hundred and sixty degrees to each other at a second spacing x along the length of the cable 1 (b). For the third twisted pair C, the fifth conductor 21 and the sixth conductor 23 are completely twisted to each other by three hundred and sixty degrees (c) at a third spacing y along the length of the cable 1 . For the fourth twisted pair D, the seventh conductor 25 and the eighth conductor 27 are completely twisted to each other by three hundred and sixty degrees (d) at a fourth spacing z along the length of the cable 1 .

Each twisted pair in twisted pairs A, B, C, and D has fixed twist pitches w, x, y, and z respectively. Each of the lay lengths w, x, y, and z is different from the lay lengths of other twisted pairs. As is known in the art, such an arrangement helps to reduce crosstalk between the twisted pairs within the cable 1, which crosstalk is known as internal crosstalk. In one embodiment of the prior art, each of twisted pairs A, B, C, and D has a unique fixed lay pitch that is slightly greater or less than 0.500 inches. Table 1 below summarizes the lay length ranges for twisted pairs A, B, C, and D.

Table 1

twisted pair Strand length Minimum lay length Maximum strand length A 0.440 0.430 0.450 B 0.410 0.400 0.420 C 0.596 0.580 0.610 D 0.670 0.650 0.690

Contents of the invention

The Applicant has recognized that the isolator 3 is a relatively expensive element of the cable core. Furthermore, the separator 3 is an extruded element with four protruding fins and does not wrap well on the reel, for example there are many air gaps in the rolled separator 3. Therefore, a shorter length of isolator 3 can be wound onto a reel of a given size.

Extruded flat divider strips are relatively cheaper than plus sign spacers3. Also, the extruded flat divider tape wraps nicely on the spool with much less air gaps. Therefore, significantly longer flat separator strips can exist on a reel of the same given size.

However, there are significant disadvantages to flat divider strips. Flat separator strips separate only two twisted pairs in a twisted pair from two other twisted pairs, such as twisted pairs A and C from twisted pairs B and D. Therefore, flat separator strips are inferior at reducing internal crosstalk compared to isolator 3 in Figures 1 and 2.

Applicants have invented a new isolator that can be extruded as a flat strip with slits formed in its thickness. Alternatively, the new isolator can be extruded as a flat strip, and a cutting operation can be used to create slits in the thickness of the strip. In a preferred embodiment, two slits are formed in the thickness of the new isolator, one on each lateral side of the new isolator. The new separator can be wound on a reel in the same way as traditional flat separator tape. Therefore, compared to the old isolator 3 of Figures 1-2, the new isolator does not include much air within the winding on the reel, and a longer new isolator can be wound on the same given size reel.

As the cable is manufactured, new isolators are fed from reels to the cable assembly area. In the cable assembly area, the wedge opens the slit. The first twisted pair is inserted into the first wedge in the open wedge, the second twisted pair is inserted into the second slit in the open slit, and the third twisted pair is placed in the new isolation on top of the isolator, and the fourth twisted pair is placed underneath the new isolator. Next, an optional shield or core cladding surrounds the cable core, and finally the outer sheath is extruded onto the cable core.

The present invention provides cost savings and storage savings of flat separator strips while providing the internal crosstalk performance of the isolator 3.

These and other objects are accomplished by an isolator for twisted pair cables, the isolator comprising a body formed as an elongated strip having a top surface and a bottom surface, wherein a gap between the top surface and the bottom surface is The distance defines the thickness of the isolator; a first side edge and a second side edge formed on the body, wherein the first side edge and the second side edge are a distance defining a width of the isolator; a first groove formed in the first side edge and extending into the body in the direction of the width of the isolator; and A second groove is formed in the second side edge and extends into the body in the direction of the width of the isolator.

Furthermore, these and other objects are accomplished by a method of forming a twisted pair cable, the method comprising: providing an isolator, the isolator including: a body formed as an elongated strip having a top surface and a bottom surface, wherein the top surface The distance between the isolator and the bottom surface defines the thickness of the isolator; a first side edge and a second side edge formed on the body, wherein the first side edge and the second side edge are a distance defining a width of the spacer; a first groove formed in the first side edge and extending into the body in the direction of the width of the spacer; and a second groove, the second groove formed in the second side edge and extending into the body in the direction of the width of the isolator; feeding the first twisted pair, the second twisted pair, the third twisted pair and the fourth twisted pair to the cable assembly area ; Feed the isolator to the cable assembly area; As the isolator passes through the cable assembly area, insert the first wedge into the first slot and open the first slot; As the isolator passes through the cable assembly area, insert the second wedge into the second slot and open the second slot; place the first twisted pair into the open first slot of the isolator; place the second twisted pair adjacent to the top surface of the isolator; place the third twisted pair into the open second slot of the isolator; positioning the fourth twisted pair adjacent the bottom surface of the isolator; and extruding the outer jacket over the isolator and the first twisted pair, the second twisted pair, the third twisted pair Three twisted pairs and a fourth twisted pair.

Furthermore, these and other objects are accomplished by a cable including: a first conductor; a first insulating material surrounding the first conductor to form a first insulated conductor; a second conductor; and a second insulating material surrounding the first conductor. the second conductor to form a second insulated conductor, wherein the first insulated conductor and the second insulated conductor are twisted with each other to form a first twisted pair; a third conductor; a third insulating material surrounding the third conductor to form a third insulated conductor; a fourth conductor; and a fourth insulating material surrounding the fourth conductor to form a fourth insulated conductor, wherein the third insulated conductor and the fourth insulated conductor are twisted with each other to form a second a twisted pair; a fifth conductor; a fifth insulating material surrounding the fifth conductor to form a fifth insulated conductor; a sixth conductor; and a sixth insulating material surrounding the sixth conductor to form a sixth insulated conductor , wherein the fifth insulated conductor and the sixth insulated conductor are twisted with each other to form a third twisted pair; a seventh conductor; a seventh insulating material surrounding the seventh conductor to form a seventh insulated conductor; eight conductors; and an eighth insulating material surrounding the eighth conductor to form an eighth insulated conductor, wherein the seventh insulated conductor and the eighth insulated conductor are twisted with each other to form a fourth twisted pair; isolator , which separates the first twisted pair from the second twisted pair, the third twisted pair and the fourth twisted pair, and separates the second twisted pair from the third twisted pair and the fourth twisted pair. a fourth twisted pair, and further separating the third twisted pair from the fourth twisted pair, wherein the isolator has a closed first notch formed on a top surface thereof and the first twisted pairs adjacent the top surface, and a closed second slot on a bottom surface thereof and the third twisted pair adjacent the bottom surface; and a jacket surrounding the isolator, the third twisted pair One pair, second pair, third pair and fourth pair.

Further scope of applicability of the invention will become apparent from the detailed description given below. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only because various changes and modifications are susceptible to various changes and modifications in light of this detailed description, which are within the spirit and scope of the invention. This will become clear to those skilled in the art.

Description of the drawings

The invention will be more fully understood from the accompanying drawings, which are given by way of illustration only and are therefore not limiting of the invention, and from the detailed description given below, and in which:

Figure 1 is a perspective view of a shielded twisted pair cable according to the prior art;

Figure 2 is a cross-sectional view taken along line II--II in Figure 1;

3 is a block diagram of a reel of an isolator fed to a cable assembly unit according to a first embodiment of the present invention;

Figure 4 is a cross-sectional view of the isolator taken along line IV--IV in Figure 3;

Figure 5 is a cross-sectional view of the isolator of Figure 4 after passing through the cable assembly unit;

Figure 6 is a block diagram of a machine for producing twisted pair cables using the isolator of Figures 3-5;

Figure 6A is a close-up perspective view of the interaction of the first wedge and the second wedge with the isolator of Figures 3-5;

Figure 7 is a cross-sectional view of a second embodiment of an isolator similar to Figure 3;

Figure 8 is a cross-sectional view of the isolator of Figure 7 after passing through the cable assembly unit;

Figure 9 is a cross-sectional view of a third embodiment of an isolator similar to Figure 3;

Figure 10 is a cross-sectional view of the isolator of Figure 9 after passing through the cable assembly unit;

Figure 11 is a cross-sectional view of a fourth embodiment of an isolator similar to Figure 3;

Figure 12 is a cross-sectional view of the isolator of Figure 11 after passing through the cable assembly unit;

Figure 13 is a cross-sectional view of a twisted pair cable having the isolator of Figures 11-12;

Figure 14 is a block diagram of a machine for producing sheets of isolator according to Figures 11-12;

Figure 15 is a close-up view of the circled portion XV of Figure 14 showing details of the extrusion die; and

16 is a perspective view of a portion of a sheet of isolator produced from section XV of the extrusion die illustrated in FIG. 15 .

Detailed ways

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey to those skilled in the art Convey the scope of the invention.

Similar reference numbers always refer to similar components. In the drawings, the thickness of certain lines, layers, parts, elements or features may be exaggerated for clarity. Unless otherwise stated, dashed lines illustrate optional features or operations.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will also be understood that terms such as those defined in commonly used dictionaries should be construed to have meanings consistent with their meanings in the context of the specification and the relevant technical field, and should not be idealized unless expressly so defined herein. Explained in a technical or overly formal manner. Well-known functions or constructions may not be described in detail for the sake of brevity and/or clarity.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms "comprising" and/or "comprising" when used in this specification specify the presence of stated features, integers, steps, operations, elements and/or parts but do not exclude one or more other features , the existence or attachment of integers, steps, operations, elements, parts and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as "between X and Y" and "between about X and Y" should be construed to include X and Y. As used herein, a phrase such as "between about X and Y" means "between about X and about Y." As used herein, a phrase such as "from about X to Y" means "from about X to about Y."

It will be understood that when an element is referred to as being "on," "attached to," "connected to" another element, "coupled to" another element, "contacting" another element, etc. The element can be directly on, attached to, connected to, coupled to, or contacting another element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on," "directly attached to," "directly connected to" another element, "directly coupled to" or "directly in contact with" another element, ” another component, there is no intervening component. Those skilled in the art will also understand that references to a structure or feature that is disposed "adjacent" to another feature may have portions that overlap or underlie the adjacent feature.

For ease of description, spatially relative terms such as "below", "below", "lower", "above", "upper", "lateral", "left", "right", etc. may be used herein. Used to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in a Figure. It will be understood that the spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the relative spatially relative descriptors used herein interpreted accordingly.

Figure 3 is a block diagram of the spool or reel 31 of the winding isolator 33A according to the first embodiment of the present invention. The isolator 33A is fed to the cable assembly area 35 and may pass over one or more powered or idler wheels or rollers 37 . More description of the cable assembly area 35 will be given with respect to FIG. 6 .

FIG. 4 is a cross-sectional view of the isolator 33A taken along line IV--IV in FIG. 3 . Isolator 33A includes a body 39 formed as an elongated strip having a top surface 41 and a bottom surface 43 . The first distance D1 exists between the top surface 41 and the bottom surface 43 and defines the thickness of the isolator 33A. A first side edge 45 and a second side edge 47 are formed on the main body 39 . The second distance D2 exists between the first side edge 45 and the second side edge 47 and defines the width of the spacer 33A.

A first groove 49 is formed in the first side edge 45 . The first groove 49 extends into the main body 39 in the width direction of the spacer 33A. More specifically, the first groove 49 extends parallel to the top surface 41 and the bottom surface 43 toward the center 53 of the isolator 33A. The center 53 extends along the central or longitudinal axis of the isolator 33A, which runs along the length of the isolator 33A. The first slot 49 extends into the body 39 at least half way to the center 53 of the isolator 33A, such as more than 75% of the way to the center 53, such as about 85% of the way to the center 53, and along Isolator 33A extends the entire length. The first slot 49 creates a first leg 55 and a second leg 57 .

A second groove 51 is formed in the second side edge 47 . The second groove 51 extends into the body 39 in the width direction of the spacer 33A. More specifically, the second groove 51 extends parallel to the top surface 41 and the bottom surface 43 toward the center 53 of the isolator 33A. The second slot 51 extends into the body 39 at least half way to the center 53 of the isolator 33A, such as more than 75% of the way to the center 53, such as about 85% of the way to the center 53, and along Isolator 33A extends the entire length. The second groove 51 creates a third leg 59 and a fourth leg 61 .

In the preferred embodiment, body 39 is formed from a dielectric material. For example, body 39 may be formed from solid or foamed polyethylene or solid or foamed fluorinated ethylene propylene (FEP), where "foamed" means purposefully incorporating air bubbles such as Gas bubbles such as these are introduced into the material to lower the overall dielectric constant of isolator 33A. Of course, other materials may be suitable for the body 39 of the isolator 33A.

In a preferred embodiment, the thickness represented by distance Dl is between 9 and 18 mils, such as between 10 and 15 mils, or about 12 mils. The width represented by distance D2 is between 90 and 130 mils, such as between 100 and 120 mils, or approximately 110 mils.

Figure 6 is a block diagram of a machine 63 for producing twisted pair cable 65 using the isolator 33A of Figures 3-5. In addition to the elements of Figure 3, the machine 63 also includes: a first spool 67 containing a first twisted pair A, a second spool 69 containing a second twisted pair B, a third spool containing a third twisted pair C. 71 and a fourth spool 73 containing a fourth twisted pair D.

During the formation of the twisted pair cable 65, the first twisted pair A, the second twisted pair B, the third twisted pair C and the fourth twisted pair D are fed to the cable assembly area 35 together with the isolator 33A. As best seen in the close-up view of Figure 6A, when isolator 33A enters cable assembly area 35, first wedge 75 is inserted into first slot 49 and opens as isolator 33A passes through cable assembly area 35. First slot 49. A separate second wedge 77 is located adjacent the second side edge 47 of the isolator 33A. As the isolator 33A passes through the cable assembly area 35, the second wedge 77 is inserted into the second slot 51 and opens the second slot 51.

Since the first wedge 75 and the second wedge 77 open the first groove 49 and the second groove 51 , the isolator 33A obtains the configuration shown in FIG. 5 . In other words, the portion of the isolator 33A in FIG. 6A to the right (upstream) side of the first wedge 75 and the second wedge 77 has the cross-section of FIG. 4 , and the portion of the isolator 33A in FIG. 6A to the first wedge 75 and the left (downstream) portion of the second wedge 77 has the cross-section of FIG. 5 . When the first wedge 75 and the second wedge 77 open the first slot 49 and the second slot 51, the body 39 of the isolator 33A may undergo permanent elastic deformation such as compression and elongation. In other words, the material forming the body 39 of the spacer 33A has low elasticity and tends to maintain shape deformation, as shown in FIG. 5 .

As best seen in Figure 5, the angle between first leg 55 and second leg 57 is approximately ninety degrees, and the angle between third leg 59 and fourth leg 61 is approximately ninety degrees Spend. Opening the first slot 49 and the second slot 51 results in a first arcuate portion 41A in the top surface 41 such that the angle between the first leg 55 and the third leg 59 is from one hundred eighty degrees to approximately ninety degrees. Furthermore, opening the first slot 49 and the second slot 51 results in a second arcuate portion 43A in the bottom surface 43 such that the angle between the second leg 57 and the fourth leg 61 is from one hundred and eighty degrees to about ninety degrees. Spend.

Within the cable assembly area 35, the first twisted pair A is placed in the open first slot 49, the second twisted pair B is placed adjacent to the top surface 41 in the first arcuate portion 41A, and the third twisted pair C is placed in the open second slot 51, and the fourth twisted pair D is placed adjacent to the bottom surface 43 in the second arcuate portion 43A. Preferably, the cable assembly area 35 applies twisting to the assembled isolator 33A and the first twisted pair A, the second twisted pair B, the third twisted pair C and the fourth twisted pair D to form the twisted core 79 .

The stranded core 79 can be fed to the shielding unit 81 . The shielding layer 7 is fed from the spool 83 into the shielding unit 81 . Within the shielding unit 81 , the shielding layer 7 encloses and surrounds the twisted core 79 . The shielding layer 7 may also include overlapping portions 9 as shown in Figures 1-2 to form a shielded twisted core 85. The shielding layer 7 may be formed by a conductive layer on a non-conductive layer. One suitable material for the conductive layer is aluminum foil, although other materials may be chosen. A suitable material for the non-conductive layer is a polyester film or biaxially oriented polyethylene terephthalate, e.g.

The shielded stranded core 85 is fed into the extruder 87 . In the extruder 87, the outer sheath 11 is extruded over the isolator 33A, the first twisted pair A, the second twisted pair B, the third twisted pair C and the fourth twisted pair D, and the shielding layer 7 to form a twisted pair cable 65. The outer sheath 11 may be made of polyvinyl chloride (PVC), low smoke halogen-free, polyethylene (PE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), ethylene trifluorochloroethylene (ECTFE) or Other foamed or void-free materials commonly used in wiring technology are formed.

The twisted pair cable 65 is typically passed through a cold water bath 88 to cure the outer jacket 11 and then accumulated onto a spool 89 . Except for the first wedge 75 and the second wedge 77 that open the first slot 49 and the second slot 51 , the machinery for manufacturing the twisted pair cable 65 is essentially known in the art.

FIG. 7 is a cross-sectional view of the isolator 33B according to the second embodiment. Isolator 33B includes a body 39B formed as an elongated strip having a top surface 41B and a bottom surface 43B. The first distance D3 exists between the top surface 41B and the bottom surface 43B and defines the thickness of the spacer 33B. The first side edge 45B and the second side edge 47B are formed on the main body 39B. The second distance D4 exists between the first side edge 45B and the second side edge 47B and defines the width of the spacer 33B.

The first groove 49B is formed in the first side edge 45B. The first groove 49B extends into the body 39B in the width direction of the spacer 33B. More specifically, the first groove 49B extends parallel to the top surface 41B and the bottom surface 43B toward the center 53B of the isolator 33B. The first slot 49B extends into the body 39B at least halfway to the center 53B of the isolator 33B, such as more than 75% of the way to the center 53B, such as about 85% of the way to the center 53B, and along Isolator 33B extends the entire length. The first slot 49B creates a first leg 55B and a second leg 57B.

The second groove 51B is formed in the second side edge 47B. The second groove 51B extends into the body 39B in the width direction of the spacer 33B. More specifically, the second groove 51B extends parallel to the top surface 41B and the bottom surface 43B toward the center 53B of the isolator 33B. The second slot 51B extends into the body 39B at least halfway to the center 53B of the isolator 33B, such as more than 75% of the way to the center 53B, such as about 85% of the way to the center 53B, and along Isolator 33B extends the entire length. The second slot 51B creates a third leg 59B and a fourth leg 61B.

Distances D3 and D4 may be within approximately the same range as described above for distances D1 and D2, respectively. Furthermore, the material used for body 39B may be the same material used for body 39 . The main difference between the embodiment of FIG. 7 and the embodiment of FIG. 4 is that the top surface 41B is formed by and included between the first flat surface 91 and the second flat surface 93 . The first step between 95. Furthermore, the bottom surface 43B is formed by the third flat surface 97 and the fourth flat surface 99 and includes the second step 101 between the third flat surface 97 and the fourth flat surface 99 .

The first step 95 and the second step 101 provide a natural bending point when the first groove 49B and the second groove 51B are opened by the first wedge 75 and the second wedge 77 . In this way, after the first groove 49 and the second groove 51 are opened, the gradient curves of the first arcuate portion 41A and the second arcuate portion 43A in FIG. 5 tend to bend toward more angles and decrease, as shown in FIG. 8 The ninety degree angles 103 and 105 are shown. However, FIG. 8 still illustrates the elongated deformation in regions 107 and 109 when isolator 33B is opened by first wedge 75 and second wedge 77 . Isolator 33B of Figures 7 and 8 may be used in conjunction with machine 63 of Figure 6 to form twisted pair cable 65B.

FIG. 9 is a cross-sectional view of the isolator 33C according to the third embodiment. Isolator 33C includes a body 39C formed as an elongated strip having a top surface 41C and a bottom surface 43C. The first distance D1 exists between the top surface 41C and the bottom surface 43C and defines the thickness of the spacer 33C. A first side edge 45C and a second side edge 47C are formed on the main body 39C. The second distance D2 exists between the first side edge 45C and the second side edge 47C and defines the width of the spacer 33C.

A first groove 49C is formed in the first side edge 45C. The first groove 49C extends into the main body 39C in the width direction of the spacer 33C. More specifically, the first groove 49C extends parallel to the top surface 41C and the bottom surface 43C toward the center 53C of the isolator 33C. The first slot 49C extends into the body 39C at least halfway to the center 53C of the isolator 33C, such as more than 75% of the way to the center 53C, such as about 85% of the way to the center 53C, and along Isolator 33C extends the entire length. The first slot 49C creates a first leg 55C and a second leg 57C.

The second groove 51C is formed in the second side edge 47C. The second groove 51C extends into the body 39C in the width direction of the spacer 33C. More specifically, the second groove 51C extends parallel to the top surface 41C and the bottom surface 43C toward the center 53C of the isolator 33C. The second slot 51C extends into the body 39C at least half way to the center 53C of the isolator 33C, such as more than 75% of the way to the center 53C, such as about 85% of the way to the center 53C, and along Isolator 33C extends the entire length. The second slot 51C creates a third leg 59C and a fourth leg 61C.

The material used for body 39C may be the same material used for body 39. The main difference between the embodiment of Figure 9 and the embodiment of Figure 4 is that the top surface 41C includes a first recessed region 107 near the midpoint between the first side edge 45C and the second side edge 47C, and the bottom surface 43C includes a second recessed region 109 near the midpoint between first side edge 45C and second side edge 47C.

In the illustrated embodiment, the first recessed area 107 is a first v-notch and the second recessed area 109 is a second v-notch. The first v-shaped notch is formed by the intersection of the first inclined surface 111 and the second inclined surface 113, wherein the first inclined surface 111 and the second inclined surface 113 intersect at an angle of approximately forty-five degrees. The second v-shaped notch is formed by the intersection of the third inclined surface 115 and the fourth inclined surface 117 , where the third inclined surface 115 and the fourth inclined surface 117 intersect at an angle of approximately forty-five degrees.

The first and second v-notches provide a natural bending point when the first and second slots 49C, 51C are opened by the first and second wedges 75, 77. In this way, after the opening of the first groove 49C and the second groove 51C, the elongation and compression of the material forming the body 39C is reduced, as best seen in Figure 10. Isolator 33C of Figures 9 and 10 may be used in conjunction with machine 63 of Figure 6 to form twisted pair cable 65C.

FIG. 11 is a cross-sectional view of the isolator 33D according to the fourth embodiment. Isolator 33D includes a body 39D formed as an elongated strip having a top surface 41D and a bottom surface 43D. The first distance D1 exists between the top surface 41D and the bottom surface 43D and defines the thickness of the isolator 33D. A first side edge 45D and a second side edge 47D are formed on the main body 39D. The second distance D2 exists between the first side edge 45D and the second side edge 47D and defines the width of the spacer 33D.

A first groove 49D is formed in the first side edge 45D. The first groove 49D extends into the main body 39D in the direction of the width of the spacer 33D. More specifically, the first groove 49D extends parallel to the top surface 41D and the bottom surface 43D toward the center 53D of the isolator 33D. The first slot 49D extends into the body 39D at least half way to the center 53D of the isolator 33D, such as more than 75% of the way to the center 53D, such as about 85% of the way to the center 53D, and along The entire length of the isolator 33D extends. The first slot 49D creates a first leg 55D and a second leg 57D.

The second groove 51D is formed in the second side edge 47D. The second groove 51D extends into the main body 39D in the direction of the width of the spacer 33D. More specifically, the second groove 51D extends parallel to the top surface 41D and the bottom surface 43D toward the center 53D of the isolator 33D. The second slot 51D extends into the body 39D at least half way to the center 53D of the isolator 33D, such as more than 75% of the way to the center 53D, such as about 85% of the way to the center 53D, and along The entire length of the isolator 33D extends. The second slot 51D creates a third leg 59D and a fourth leg 61D.

The material used for body 39D may be the same material used for body 39. The main differences between the embodiment of Figure 11 and the embodiment of Figure 4 are that the top surface 41D includes a first recessed region 119 near the midpoint between the first side edge 45D and the second side edge 47D, and the bottom surface 43D A second recessed region 121 is included near the midpoint between the first side edge 45D and the second side edge 47D.

In the illustrated embodiment, the first recessed area 119 is a first v-notch and the second recessed area 121 is a second v-notch. The first v-shaped notch is formed by the intersection of a first inclined surface 123 and a second inclined surface 125, where the first inclined surface 123 and the second inclined surface 125 intersect at an angle of approximately ninety degrees. The second v-shaped notch is formed by the intersection of the third inclined surface 127 and the fourth inclined surface 129 , where the third inclined surface 127 and the fourth inclined surface 129 intersect at an angle of approximately ninety degrees.

The first and second v-notches provide a natural bending point when the first and second slots 49D, 51D are opened by the first and second wedges 75, 77. In this way, after the opening of the first groove 49D and the second groove 51D, the elongation and compression of the material forming the body 39D is reduced, as best seen in Figure 12. As also seen in Figure 12, the angle between the first leg 55D and the third leg 59D is approximately ninety degrees, and the angle between the second leg 57D and the fourth leg 61D is approximately ninety degrees . Likewise, the angle between first leg 55D and second leg 57D is approximately ninety degrees, and the angle between third leg 59D and fourth leg 61D is approximately ninety degrees. Isolator 33D of Figures 11 and 12 may be used in conjunction with machine 63 of Figure 6 to form twisted pair cable 65D.

Figure 13 is a cross-sectional view of twisted pair cable 65D. Twisted pair cable 65D includes first twisted pair 131 . The first twisted pair 131 includes a first insulated conductor 135 formed by surrounding a first conductor 135B with a first insulating material 135A and a second insulated conductor 137 formed by surrounding a second conductor 137B with a second insulating material 137A. The first insulated conductor 135 and the second insulated conductor 137 are twisted with each other to form a first twisted pair 131 .

The second twisted pair 139 includes a third insulated conductor 141 formed by surrounding a third conductor with a third insulating material and a fourth insulated conductor 143 formed by surrounding a fourth conductor with a fourth insulating material, wherein the third insulated conductor 141 and the fourth insulated conductor 143 are twisted with each other to form a second twisted pair 139 .

The third twisted pair 145 includes a fifth insulated conductor 147 formed by surrounding a fifth conductor with a fifth insulating material and a sixth insulated conductor 149 formed by surrounding a sixth conductor with a sixth insulating material, wherein the fifth insulated conductor 147 and The sixth insulated conductors 149 are twisted with each other to form a third twisted pair 145 .

The fourth twisted pair 151 includes a seventh insulated conductor 153 formed by surrounding a seventh conductor with a seventh insulating material and an eighth insulated conductor 155 formed by surrounding an eighth conductor with an eighth insulating material, wherein the seventh insulated conductor 153 and The eighth insulated conductors 155 are twisted with each other to form a fourth twisted pair 151 .

The twisting lengths w, x, y, and z of the first twisted pair 131, the second twisted pair 139, the third twisted pair 145, and the fourth twisted pair 151 may be the same as those listed in Table 1 for the pair. Strands A, B, C and D are the same. For example, the first twist length w of the first twisted pair 131 may be shorter than the third twist length y of the third twisted pair 145, and the second twist length x of the second twisted pair 139 may be shorter than the third twist length y. The fourth twist length z of the four twisted pairs 151. It should be noted that other lay lengths than those listed in Table 1 may be employed while practicing the benefits of the present invention.

The first to eighth insulating materials may be formed of flexible plastic materials with flame retardant and smoke suppression properties, such as polymers or foamed polymers commonly used in the wiring field, such as fluorinated ethylene propylene (FEP), polyethylene (PE)) or polypropylene (PP). The radial thickness of the first through eighth insulating materials will typically be greater than seven mils, such as about ten mils or about eleven mils. The first through eighth conductors may be void-free or stranded, and may be formed from a conductive metal or alloy such as copper. In one embodiment, the first through eighth conductors are each approximately twenty-three gauge size void-free copper wire.

Similar to Figure 1, the cable cores of twisted pair cable 65D may be twisted in the direction of arrow 30 to form core strands. In the illustrated embodiment, the direction 30 is opposite to the twist direction of the first twisted pair 131 , the second twisted pair 139 , the third twisted pair 145 and the fourth twisted pair 151 and may provide as The advantages are discussed in US Pat. No. 6,770,819, which is incorporated herein by reference. However, this is not a necessary feature, as the advantages of the invention will still be apparent if the direction 30 of the core strands is the same as the twisting direction of the twisted pairs.

The isolator 33D separates the first twisted pair 131 from the second twisted pair 139, the third twisted pair 145 and the fourth twisted pair 151, and separates the second twisted pair 139 from the third twisted pair. 145 is separated from the fourth twisted pair 151, and the third twisted pair 145 is also separated from the fourth twisted pair 151. The isolator 33D has a closed first notch formed on its top surface 41D, and the first twisted pair 131 abuts the top surface 41D. Isolator 33D also has a closed second notch on its bottom surface 43D, and third twisted pair 145 adjoins bottom surface 43D. The second twisted pair 139 resides in the open fourth slot 51D, and the fourth twisted pair 151 resides in the open first slot 49D.

The shielding layer 7 surrounds the isolator 33D and the first, second, third and fourth twisted pairs 131 , 139 , 145 and 151 . The outer sheath 11 surrounds the shield 7 , the isolator 33D and the first, second, third, fourth and fourth twisted pairs 131 , 139 , 145 and 151 . In all embodiments, the shield 7 is optional and/or can be removed, especially if the cable is employed in an environment where alien crosstalk is not an issue, e.g. the cable is not in contact with other sources or cables that emit or are susceptible to EMF Adjacent. Alien crosstalk performance in twisted pair cables as described above can be enhanced by employing a striped jacket, as shown in U.S. Patent 5,796,046 and published U.S. Application 2005/0133246, both of which are incorporated by reference. Enter this article. Alien crosstalk performance may be further enhanced by employing strand modulation and/or core-strand modulation, as shown in assignee's U.S. Patent 6,875,928, which is incorporated herein by reference.

Figure 14 is a block diagram of one potential embodiment of a machine 161 for producing the sheet 163 of the isolator 33D according to Figures 11-12. Machine 161 is an extruder 169 and receives pellets 165 from a hopper 167 . Pellets may be formed from polyethylene or fluorinated ethylene propylene (FEP) or other such materials. Extruder 169 heats pellets 165 into a slurry. The slurry can be extruded through the extrusion die 171 in a void-free form or together with a blowing agent. The sheet 163 of the separator 33D may pass through one or more powered or idle rollers 162 and then be accumulated onto a spool 164. Of course, the sheets 163 of the isolator 33D preferably pass through a cooling device, like the water bath 88 of Figure 6, before being stored on the reel 164. Apart from the construction of the extrusion die 171, the construction of the machine 161 is essentially consistent with known machines for producing sheets of isolator "strips".

Figure 15 is a close-up view of the circled portion XV of Figure 14 showing details of the extrusion die 171. The extrusion die has complementary features to produce the features of isolator 33D of Figures 11-12. For example, extrusion die 171 has "reverse" or complementary protrusions to create first and second grooves 49D, 51D, first leg 55D, second leg 57D, third leg 59D and fourth leg 61D. , as well as the first concave area 119 and the second concave area 121 . In practice, the sheet 163 of isolators 33D may include twenty to twenty-five isolators 33D arranged side by side.

FIG. 16 is a perspective view of a portion of sheet 163 of isolator 33D produced from section XV of extrusion die 171 . The portion shown of the sheet 163 of isolators 33D includes three isolators 33D, as well as portions of separators 33B on each side of the left and right sides. Arrow 173 indicates the point at which sheet 163 of spacer 33D is cut to form individual spacers 33D. Cutting is typically performed by a blade or laser as the sheet is driven through it and the individual separators 33D are accumulated on a separator reel 31 as shown in Figures 3 and 6 for shipment to the customer, e.g. Cable manufacturer. As mentioned previously, except for the shape of the extrusion die 171 , the extrusion and cutting process can be performed in the same manner as previously performed for the manufacture of the separator strips. Additionally, the extrusion die 171 is replaced with a flat sheet extrusion die and all features of the isolator 33D (first It would be possible to cut grooves 49D and second grooves 51D as well as first and second recessed areas 119 and 121) into the spacer 33D.

While the invention has been described, it will obviously be possible to vary the invention in various ways. Such changes are not to be considered a departure from the spirit and scope of the invention, and all such modifications which will be apparent to those skilled in the art are intended to be included within the scope of the following claims.

Claims (20)

1. An isolator for a twisted pair cable comprising:

a body extruded as a flat ribbon having a top surface and a bottom surface, wherein a distance between the top surface and the bottom surface defines a thickness of the body;

a first side edge and a second side edge formed on the body, wherein a distance between the first side edge and the second side edge defines a width of the body;

a deformable first slot formed in the first side edge and extending into the body in the direction of the width of the body; and

a deformable second slot formed in the second side edge and extending into the body in the direction of the width of the body.

2. The isolator of claim 1, wherein the first groove extends parallel to the top and bottom surfaces toward a center of the isolator, and wherein the second groove extends parallel to the top and bottom surfaces toward the center of the isolator.

3. The isolator of claim 2, wherein the first groove extends into the body at least half way to the center of the isolator, and wherein the second groove extends into the body at least half way to the center of the isolator.

4. The isolator of claim 1, wherein the body is formed of a dielectric material.

5. The separator of claim 4, wherein the dielectric material is void-free or foamed polyethylene or void-free or foamed Fluorinated Ethylene Propylene (FEP).

6. The separator of any of claims 1, 2, 3, 4, or 5, wherein the thickness of the body is between 9 and 18 mils.

7. The separator of any of claims 1, 2, 3, 4, or 5, wherein the width of the body is between 90 and 130 mils.

8. The isolator of any one of claims 1, 2, 3, 4, or 5, wherein the top surface includes a first recessed area proximate a midpoint between the first side edge and the second side edge, and wherein the bottom surface includes a second recessed area proximate a midpoint between the first side edge and the second side edge.

9. The isolator according to claim 8, wherein said first recessed area is a first v-shaped notch, and wherein said second recessed area is a second v-shaped notch.

10. The isolator of claim 9, wherein the first v-notch is formed by a first angled surface intersecting a second angled surface, and wherein the first angled surface meets the second angled surface at an angle of approximately ninety degrees, and wherein the second v-notch is formed by a third angled surface intersecting a fourth angled surface, and wherein the third angled surface meets the fourth angled surface at an angle of approximately ninety degrees.

11. The isolator of any one of claims 1, 2, 3, 4, or 5, wherein the top surface is formed from first and second planar surfaces and a first step between the first and second planar surfaces, and wherein the bottom surface is formed from third and fourth planar surfaces and a second step between the third and fourth planar surfaces.

12. A method of forming a twisted pair cable, comprising:

providing an isolator, the isolator comprising:

A body extruded as a flat ribbon having a top surface and a bottom surface, wherein a distance between the top surface and the bottom surface defines a thickness of the body;

a first side edge and a second side edge formed on the body, wherein a distance between the first side edge and the second side edge defines a width of the body;

a first slot formed in the first side edge and extending into the main body in the direction of the width of the main body; and

a second groove formed in the second side edge and extending into the main body in the direction of the width of the main body;

feeding the first twisted pair, the second twisted pair, the third twisted pair, and the fourth twisted pair to a cable assembly area;

feeding the isolator to the cable assembly area;

inserting a first wedge into the first groove and opening the first groove as the isolator enters the cable assembly area, thereby causing deformation of the flat ribbon;

inserting a second wedge into the second groove and opening the second groove as the isolator enters the cable assembly area, thereby causing deformation of the flat ribbon;

Placing the first twisted pair into an open first slot of the separator;

placing the second twisted pair adjacent to the top surface of the isolator;

placing the third twisted pair into an open second slot of the separator;

placing the fourth twisted pair adjacent to the bottom surface of the separator; and

extruding an outer jacket over the separator and the first twisted pair, the second twisted pair, the third twisted pair, and the fourth twisted pair.

13. The method of claim 12, further comprising:

core twist is applied to the separator and the first, second, third and fourth twisted pairs prior to the extruding step.

14. The method of claim 12, further comprising:

the separator and the first, second, third and fourth twisted pairs are surrounded by a shielding layer prior to the extruding step.

15. The method of claim 12, further comprising:

imparting core twist to the separator and the first, second, third and fourth twisted pairs; and

The separator and the first, second, third and fourth twisted pairs are surrounded by a shielding layer prior to the extruding step.

16. A cable, comprising:

a first conductor; a first insulating material surrounding the first conductor to form a first insulating conductor; a second conductor; and a second insulating material surrounding the second conductor to form a second insulated conductor, wherein the first and second insulated conductors are twisted with each other to form a first twisted pair;

a third conductor; a third insulating material surrounding the third conductor to form a third insulated conductor; a fourth conductor; and a fourth insulating material surrounding the fourth conductor to form a fourth insulated conductor, wherein the third and fourth insulated conductors are stranded with each other to form a second twisted pair;

a fifth conductor; a fifth insulating material surrounding the fifth conductor to form a fifth insulated conductor; a sixth conductor; and a sixth insulating material surrounding the sixth conductor to form a sixth insulated conductor, wherein the fifth insulated conductor and the sixth insulated conductor are twisted with each other to form a third twisted pair;

A seventh conductor; a seventh insulating material surrounding the seventh conductor to form a seventh insulating conductor; an eighth conductor; and an eighth insulating material surrounding the eighth conductor to form an eighth insulated conductor, wherein the seventh insulated conductor and the eighth insulated conductor are twisted with each other to form a fourth twisted pair;

an isolator separating the first twisted pair from the second twisted pair, the third twisted pair and the fourth twisted pair, separating the second twisted pair from the third twisted pair and the fourth twisted pair, and also separating the third twisted pair from the fourth twisted pair, wherein the isolator comprises:

a body extruded as a flat ribbon having a top surface and a bottom surface, wherein a distance between the top surface and the bottom surface defines a thickness of the body;

a first side edge and a second side edge formed on the body, wherein a distance between the first side edge and the second side edge defines a width of the body;

a deformable first slot formed in the first side edge and extending into the body in the direction of the width of the body; and

A deformable second slot formed in the second side edge and extending into the body in the direction of the width of the body, wherein the separator has a closed first notch formed on the top surface thereof and the first twisted pair is adjacent the top surface, and the separator has a closed second notch on the bottom surface thereof and the third twisted pair is adjacent the bottom surface; and

a jacket surrounding the separator, the first twisted pair, the second twisted pair, the third twisted pair, and the fourth twisted pair.

17. The cable of claim 16, wherein the closed first notch is formed by an abutment of a first inclined surface in the top surface with a second inclined surface in the top surface, and wherein the closed second notch is formed by an abutment of a third inclined surface in the bottom surface with a fourth inclined surface in the bottom surface.

18. The cable of claim 16, further comprising:

a shielding layer, wherein the shielding layer surrounds the separator and the first, second, third, and fourth twisted pairs, and the shielding layer resides within the jacket.

19. The cable of claim 16, wherein the separator and the first, second, third, and fourth twisted pairs have core twist within an outer jacket.

20. The cable of claim 16, further comprising:

a shielding layer, wherein the shielding layer surrounds the separator and the first, second, third, and fourth twisted pairs, and the shielding layer resides within the jacket, and wherein the separator and the first, second, third, and fourth twisted pairs have core twist within the shielding layer.