High performance support-separator for communications cables

[0001] This application is a continuation in part of and Applicants hereby claim priority under all rights to which they are entitled under 35 U.S.C. Section 120 based upon the U.S. application Ser. No. 09/939,375 now U.S. Pat. No. 6,639,152 filed on Aug. 25, 2001 and based on a 35 U.S.C. § 371 filing of PCT/USS02/13831 application filed on May 1, 2002 which designates the United States as the receiving office.

[0002] This invention relates to high performance multi-media communications cables utilizing paired or unpaired electrical conductors or optical fibers. More particularly, it relates to cables having a central core defining singular or plural individual pair channels. The communications cables have interior core support-separators that define a clearance through which conductors or optical fibers may be disposed.

[0003] Many communication systems utilize high performance cables normally having four pairs or more that typically consist of two twisted pairs transmitting data and two receiving data as well as the possibility of four or more pairs multiplexing in both directions. A twisted pair is a pair of conductors twisted about each oilier. A transmitting twisted pair and a receiving twisted pair often form a subgroup in a cable having four twisted pairs. High-speed data communications media in current usage includes pairs of wire twisted together to form a balanced transmission line. Optical fiber cables may include such twisted pairs or replace them altogether with optical transmission media (fiber optics).

[0004] When twisted pairs are closely placed, such as in a communications cable, electrical energy may be transferred from one pair of a cable to another. Energy transferred between conductor pairs is undesirable and referred to as crosstalk. The Telecommunications Industry Association and Electronics Industry Association have defined standards for crosstalk, including TIA/EIA-568A. The International Electrotechnical Commission has also defined standards for data communication cable crosstalk, including ISO/IEC 11801. One high-performance standard for 100 MHz cable is ISO/IEC 11801, Category 5. Additionally, more stringent standards are being implemented for higher frequency cables including Category 6 and Category 7, which includes frequencies of 200 and 600 MHz, respectively. Industry standards cable specifications and known commercially available products are listed in Table 1.

[0005]

TABLE 1
INDUSTRY STANDARD CABLE SPECIFICATIONS
			ANIXTER	ANIXTER
		TIA CAT 6	XP6	XP7
ALL DATA AT		DRAFT 10	R3.00XP	R3.00XP
100 MHz	TIA CAT 5e	11/15/01	11/00	11/00
MAX TEST	100 MHz	250 MHz	250 MHz	350 MHz
FREQUENCY
ATTENTUATION	22.0 db	19.8 db	21.7 db	19.7 db
POWER SUM	32.3 db	42.3 db	34.3 db	44.3 db
NEXT
ACR	13.3 db	24.5 db
POWER SUM	10.3 db	22.5 db	12.6 db	23.6 db
ACR
POWER SUM	20.8 db	24.8 db	23.8 db	25.8 db
ELFEXT
RETURN LOSS	20.1 db	20.1 db	21.5 db	22.5 db

[0006]

TABLE 2
CLASSES OF REACTION TO FIRE PERFORMANCE
FOR POWER, CONTROL AND COMMUNICATION
CABLES(*)
Class	Test method(s)	Classification criteria(1)	Additional classification
AC	EN ISO 1716	PCS ≦ 2.0 MJ.kg−1(2)
BC	EN 50266-2-x(3)	FS ≦ 2.0 m; and	Smoke production(5) and Flaming
	And	THR1200s ≦ 30 MJ; and	droplets/particles(7);
		Peak RHR ≦ 60 kW; and	Acidity/Corrosivity(8)
		FIGRA ≦ 150 W.s−1
	EN 50265-2-1	H ≦ 425 mm
CC	EN 50266-2-y(4)	FS ≦ 2.0 m; and	Smoke production(6) and Flaming
	And	THR600s ≦ 15 MJ; and	droplets/particles(7);
		Peak RHR ≦ 60 kW; and	Acidity/Corrosivity(8)
		FIGRA ≦ 150 W.s−1
	EN 50265-2-1	H ≦ 425 mm
DC	EN 50266-2-y(4)	FS ≦ 2.5 m; and	Smoke production(6) and Flaming
	And	THR600s ≦ 35 MJ; and	droplets/particles(7);
		Peak RHR ≦ 200 kW; and	Acidity/Corrosivity(8)
		FIGRA ≦ 250 W.s−1
	EN 50265-2-1	H ≦ 425 mm
EC	EN 50265-2-1	H ≦ 425 mm	Flaming droplets/particles(7);
			Acidity/Corrosivity(8)
FC	No performance determined
(1)Symbols used: PCS—gross calorific potential; FS—flame spread; THR—total heat release, RHR—rate of heat release; FIGRA—fire growth rate; TSP—total smoke production; SPR—smoke production rate; H—flame spread.
(2)Mineral insulated cables without a polymeric sheath, as defined in HD 50 386, are deemed to satisfy the Class AC requirement without the need for testing.
(3)EN 50266-2-4 modified on the basis of FIPEC scenario 2 and to include heat release and smoke measurements.
(4)EN 50266-2-4 modified to include heat release and smoke measurements.
(5)EN 50266-2-x: s1 = TSP ≦ 100 m2 and Peak SPR ≦ 0.25 m2/s; s2 = TSP ≦ 200 m2 and Peak SPR ≦ 0.5 m2/s; s3 = not s1 or s2.
(6)EN 50266-2-y: s1 = TSP ≦ 50 m2 and Peak SPR ≦ 0.25 m2/s; s2 = TSP ≦ 100 m2 and Peak SPR ≦ 0.5 m2/s; s3 = not s1 or s2.
(7)EN 50265-2-1 (mod.): d0 = No flaming droplets/particles; d1 = No flaming droplets/particles persisting longer than x s; d2 = not d0 or d1.
(8)EN 50267-2-3: a1 = conductivity < 2.5 μS/mm and pH > 4.3; a2 = conductivity < 10 μS/mm and pH > 4.3; a3 = not a1 or a2. No declaration = No Performance Determined.
(*)This Classification table applies to power, control and communication cables designed for use in buildings and other civil engineering works, with a voltage rating up to 1000 V for alternating current and 1500 V for direct current. It does not cover control and power circuits covered under the Machinery Directive 98/37/EC or lifts Directive 95/16/EC

[0007] In conventional cable, each twisted pair of conductors for a cable has a specified distance between twists along the longitudinal direction. That distance is referred to as the pair lay. When adjacent twisted pairs have the same pair lay and/or twist direction, they tend to lie within a cable more closely spaced than when they have different pair lays and/or twist direction. Such close spacing increases the amount of undesirable cross-talk that occurs. Therefore, in many conventional cables, each twisted pair within the cable has a unique pair lay in order to increase the spacing between pairs and thereby to reduce the cross-talk between twisted pairs of a cable. Twist direction may also be varied. Along with varying pair lays and twist directions, individual solid metal or woven metal air shields can be used to electro-magnetically isolate pairs from each other or isolate the pairs from the cable jacket.

[0008] Shielded cable, although exhibiting better cross-talk isolation, is more difficult, time consuming and costly to manufacture, install, and terminate. Individually shielded pairs must generally be terminated using special tools, devices and techniques adapted for the job, also increasing cost and difficulty.

[0009] One popular cable type meeting the above specifications is Unshielded Twisted Pair (UTP) cable. Because it does not include shielded pairs, UTP is preferred by installers and others associated with wiring building premises, as it is easily installed and terminated. However, UTP fails to achieve superior cross-talk isolation such as required by the evolving higher frequency standards for data and other state of the art transmission cable systems, even when varying pair lays are used.

[0010] Some cables have used supports in connection with twisted pairs. These cables, however, suggest using a standard “X”, or “+” shaped support, hereinafter both referred to as the “X” support. Protrusions may extend from the standard “X” support. The protrusions of these prior inventions have exhibited substantially parallel sides.

[0011] The document, U.S. Pat. No. 3,819,443, hereby incorporated by reference, describes a shielding member comprising laminated strips of metal and plastics material that are cut, bent, and assembled together to define radial branches on said member. It also describes a cable including a set of conductors arranged in pairs, said shielding member and an insulative outer sheath around the set of conductors. In this cable the shielding member with the radial branches compartmentalizes the interior of the cable. The various pairs of the cable are therefore separated from each other, but each is only partially shielded, which is not so effective as shielding around each pair and is not always satisfactory.

[0012] The solution to the problem of twisted pairs lying too closely together within a cable is embodied in three U.S. Pat. No. 6,150,612 to Prestolite, U.S. Pat. No. 5,952,615 to Filotex, and U.S. Pat. No. 5,969,295 to CommScope incorporated by reference herein, as well as an earlier similar design of a cable manufactured by Belden Wire & Cable Company as product number 1711A. The prongs or splines in the Belden cable provide superior crush resistance to the protrusions of the standard “X” support. The superior crush resistance better preserves the geometry of the pairs relatives to each other and of the pairs relative to the other parts of the cables such as the shield. In addition, the prongs or splines in this invention preferably have a pointed or slightly rounded apex top which easily accommodates an overall shield. These cables include four or more twisted pair media radially disposed about a “+”-shaped core. Each twisted pair nests between two fins of the “+”-shaped core, being separated from adjacent twisted pairs by the core. This helps reduce and stabilize crosstalk between the twisted pair media. U.S. Pat. No. 5,789,711 to Belden describes a “star” separator that accomplishes much of what has been described above and is also herein incorporated by reference.

[0013] However, these core types can add substantial cost to the cable, as well as excess material mass which forms a potential fire hazard, as explained below, while achieving a crosstalk reduction of typically 3 dB or more. This crosstalk value is based on a cable comprised of a fluorinated ethylene-propylene (FEP) conductors with PVC jackets as well as cables constructed of FEP jackets with FEP insulated conductors. Cables where no separation between pairs exist will exhibit smaller cross-talk values. When pairs are allowed to shift based on “free space” within the confines of the cable jacket, the fact that the pairs may “float” within a free space can reduce overall attenuation values due to the ability to use a larger conductor to maintain 100 ohm impedance. The trade-off with allowing the pairs to float is that the pair of conductors tend to separate slightly and randomly. This undesirable separation contributes to increased structural return loss (SRL) and more variation in impedance. One method to overcome this undesirable trait is to twist the conductor pairs with a very tight lay. This method has been proven impractical because such tight lays are expensive and greatly limits the cable manufacturer's throughput and overall production yield. An improvement included by the present invention to structural return loss and improved attenuation is to provide grooves within channels for conductor pairs such that the pairs are fixedly adhered to the walls of these grooves or at least forced within a confined space to prevent floating simply by geometric configuration. This configuration is both described herewithin and referenced in U.S. patent application Ser. No. 09/939,375, filed Aug. 25, 2001. A “rifling” or “ladder-like” separator design also contributes to improved attenuation, power sum NEXT (near end cross talk), power sum ACR (attenuation cross-talk ratio) and ELFEXT (equal level far end cross-talk) by providing for better control of spacing of the pairs, adding more air-space, and allowing for “pair-twinning” at different lengths. Additional benefits include reduction of the overall material mass required for conventional spacers, which contributes to flame and smoke reduction.

[0014] In building designs, many precautions are taken to resist the spread of flame and the generation of and spread of smoke throughout a building in case of an outbreak of fire. Clearly, the cable is designed to protect against loss of life and also minimize the costs of a fire due to the destruction of electrical and other equipment. Therefore, wires and cables for building installations are required to comply with the various flammability requirements of the National Electrical Code (NEC) in the U.S. as well as International Electrotechnical Commission (EIC) and/or the Canadian Electrical Code (CEC).

[0015] Cables intended for installation in the air handling spaces (i.e. plenums, ducts, etc.) of buildings are specifically required by NEC/CEC/IEC to pass the flame test specified by Underwriters Laboratories Inc. (UL), UL-910, or its Canadian Standards Association (CSA) equivalent, the FT6. The UL-910 and the FT6 represent the top of the fire rating hierarchy established by the NEC and CEC respectively. Also important are the UL 1666 Riser test and the IEC 60332-3C and D flammability criteria. Cables possessing these ratings, generically known as “plenum” or “plenum rated” or “riser” or “riser rated”, may be substituted for cables having a lower rating (i.e. CMR, CM, CMX, FT4, FTI or their equivalents), while lower rated cables may not be used where plenum or riser rated cables are required.

[0016] Cables conforming to NEC/CEC/IEC requirements are characterized as possessing superior resistance to ignitability, greater resistant to contribute to flame spread and generate lower levels of smoke during fires than cables having lower fire ratings. Often these properties can be anticipated by the use of measuring a Limiting Oxygen Index (LOI) for specific materials used to construct the cable. Conventional designs of data grade telecommunication cable for installations in plenum chambers have a low smoke generating jacket material, e.g. of a specially filled PVC formulation or a fluoropolymer material, surrounding a core of twisted conductor pairs, each conductor individually insulated with a fluorinated insulation layer. Cable produced as described above satisfies recognized plenum test requirements such as the “peak smoke” and “average smoke” requirements of the Underwriters Laboratories, Inc., UL910 Steiner tunnel test and/or Canadian Standards Association CSA-FT6 (Plenum Flame Test) while also achieving desired electrical performance in accordance with EIA/TIA-568A for high frequency signal transmission.

[0017] While the above described conventional cable, including the Belden 1711A cable design, due in part to their use of fluorinated polymers, meets all of the above design criteria, the use of fluorinated polymers is extremely expensive and may account for up to 60% of the cost of a cable designed for plenum usage. A solid core of these communications cables contributes a large volume of fuel to a potential cable fire. Forming the core of a fire resistant material, such as with FEP (fluorinated ethylene-propylene), is very costly due to the volume of material used in the core, but it should help reduce flame spread over the 20 minute test period. Reducing the mass of material by redesigning the core and separators within the core is another method of reducing fuel and thereby reducing smoke generation and flame spread. For the commercial market in Europe, low smoke fire retardant polyolefin materials have been developed that will pass the EN (European Norm) 502666-Z-X Class B relative to flame spread, total heat release, related heat release, and fire growth rate. Prior to this inventive development, standard cable constructions requiring the use of the aforementioned expensive fluorinated polymers, such as FEP, would be needed to pass this rigorous test. Using low smoke fire retardant polyolefins for specially designed separators used in cables that meet the more stringent electrical requirements for Categories 6 and 7 and also pass the new norm for flammability and smoke generation is a further subject of this invention.

[0018] Solid flame retardant/smoke suppressed polyolefins may also be used in connection with fluorinated polymers. Commercially available solid flame retardant/smoke suppressed polyolefin compounds all possess dielectric properties inferior to that of FEP and similar fluorinated polymers. In addition, they also exhibit inferior resistance to burning and generally produce more smoke than FEP under burning conditions. A combination of the two different polymer types can reduce costs while minimally sacrificing physio-chemical properties. An additional method that has been used to improve both electrical and flammability properties includes the irradiation of certain polymers that lend themselves to crosslinking. Certain polyolefins are currently in development that have proven capable of replacing fluoropolymers for passing these same stringent smoke and flammability tests for cable separators, also known as “cross-webs”. Additional advantages with the polyolefins are reduction in cost and toxicity effects as measured during and after combustion.

[0019] A high performance communications data cable utilizing twisted pair technology must meet exacting specification with regard to data speed, electrical,as well as flammability and smoke characteristics. The electrical characteristics include specifically the ability to control impedance, near-end cross-talk (NEXT), ACR (attenuation cross-talk ratio) and shield transfer impedance. A method used for twisted pair data cables that has been tried to meet the electrical characteristics, such as controlled NEXT, is by utilizing individually shielded twisted pairs (ISTP). These shields insulate each pair from NEXT. Data cables have also used very complex lay techniques to cancel E and B (electric and magnetic fields) to control NEXT. In addition, previously manufactured data cables have been designed to meet ACR requirements by utilizing very low dielectric constant insulation materials. Use of the above techniques to control electrical characteristics have inherent problems that have lead to various cable methods and designs to overcome these problems.

[0020] Recently, the development of “high-end” electrical properties for Category 6 and 7 cables has increased the need to determine and include power sum NEXT (near end crosstalk) and power sum ELFEXT (equal level far end crosstalk) considerations along with attenuation, impedance, and ACR values. These developments have necessitated the development of more highly evolved separators that can provide offsetting of the electrical conductor pairs so that the lessor performing electrical pairs can be further separated from other pairs within the overall cable construction.

[0021] Recent and proposed cable standards are increasing cable maximum frequencies from 100–200 MHz to 250–700 Mhz. The maximum upper frequency of a cable is that frequency at which the ACR (attenuation/cross-talk ratio) is essentially equal to 1. Since attenuation increases with frequency and cross-talk decreases with frequency, the cable designer must be innovative in designing a cable with sufficiently high cross-talk. This is especially true since many conventional design concepts, fillers, and spacers may not provide sufficient cross-talk at the higher frequencies.

[0022] Current separator designs must also meet the UL 910 flame and smoke criteria using both fluorinated and non-fluorinated jackets as well as fluorinated and non-fluorinated insulation materials for the conductors of these cable constructions. In Europe, the trend continues to be use of halogen free insulation for all components, which also must meet stringent flammability regulations.

[0023] Individual shielding is costly and complex to process. Individual shielding is highly susceptible to geometric instability during processing and use. In addition, the ground plane of individual shields, 360° in ISTP's—individually shielded twisted pairs is also an expensive process. Lay techniques and the associated multi-shaped anvils of the present invention to achieve such lay geometries are also complex, costly and susceptible to instability during processing and use. Another problem with many data cables is their susceptibility to deformation during manufacture and use. Deformation of the cable geometry, such as the shield, also potentially severely reduces the electrical and optical consistency.

[0024] Optical fiber cables exhibits a separate set of needs that include weight reduction (of the overall cable), optical functionality without change in optical properties and mechanical integrity to prevent damage to glass fibers. For multi-media cable, i.e. cable that contains both metal conductors and optical fibers, the set of criteria is often incompatible. The use of the present invention, however, renders these often divergent set of criteria compatible. Specifically, optical fibers must have sufficient volume in which the buffering and jacketing plenum materials (FEP and the like) covering the inner glass fibers can expand and contract over a broad temperature range without restriction, for example −40 C. to 80 C. experienced during shipping. It has been shown by Grune, et. al., among others, that cyclical compression and expansion directly contacting the buffered glass fiber causes excess attenuation light loss (as measured in dB) in the glass fiber. The design of the present invention allows for designation and placement of optical fibers in clearance channels provided by the support-separator, having multi-anvil shaped profiles. It would also be possible to place both glass fiber and metal conductors in the same designated clearance channel if such a design is required. In either case the forced spacing and separation from the cable jacket (or absence of a cable jacket) would eliminate the undesirable set of cyclical forces that cause excess attenuation light loss. In addition, fragile optical fibers are susceptible to mechanical damage without crush resistant members (in addition to conventional jacketing). The present invention also addresses this problem.

[0025] The need to improve the cable and cable separator design, reduce costs, and improve both flammability and electrical properties continues to exist.

[0026] This invention provides a lower cost communications cable exhibiting improved electrical, flammability, and optionally, optical properties. The cable has an interior support extending along the longitudinal length of the communications cable. The interior support has a central region extending along the longitudinal length of the interior support. In the preferred configuration, the cable includes a geometrically symmetrical core support-separator with a plurality of either solid or foamed anvil-shaped, rifled and ladder sections that extend radially outward from the central region along the longitudinal or axial length of the cable's central region. The core support-separator is optionally foamed and has an optional hollow center. Each section that is anvil-shaped is adjacent to each other with a minimum of two adjacent anvil-shaped sections or a singular anvil shape that extends along the central core. The rifled separator profiles with ladder-like “step-sections” are similar to standard “X” supports with the major difference that they include rifled ladder-like step sections along the radially extending portions of the “X”.

[0027] These various shaped sections of the core support-separator may be helixed as the core extends along the length of the communications cable. Each of the adjacent shaped sections defines a clearance which extends along the longitudinal length of the multi-anvil shaped core support-separator. The clearance provides a channel for each of the conductors/optical fibers or conductor pairs used within the cable. The clearance channels formed by the various shaped core support-separators extend along the same length of the central portion. The channels are either semi-circular, fully circular, or stepped in a circular-like manner shaped cross-section with completely closed surfaces in the radial direction toward the center portion of the core and optionally opened or closed surfaces at the outer radial portion of the same core. Adjacent channels are separated from each other to provide a chamber for at least a pair of conductors or an optical fiber or optical fibers.

[0028] The various shaped core support-separators of this invention provides a superior crush resistance to the protrusions of the standard “X” or other similar supports. A superior crush resistance is obtained by the arch-like design for the anvil-shaped separators that provide clearance channels for additional support to the outer section of the cable. The various shaped cores better preserves the geometry of the pairs relative to each other and of the pairs relative to the other parts of the cables, such as the possible use of a shield or optical fibers. The anvil-shape provides an exterior surface that essentially establishes the desired roundness for cable manufacturers. The exterior roundness ensures ease of die development and eventual extrusion. The rounded surface of the core also allows for easy accommodation of an overall external shield.

[0029] The rifled shape separators with ladder-like sections provide similar crush resistance to the standard “X” supports with the additional feature that the center portion of the separator may have solid sections that can be adjusted in step-like increments such that conductor spacing can be controlled with a degree of precision. Specifically, the conductors can be set apart so that individual or sets of pairs can be spaced closer or farther from one another, allowing for better power sum values of equal level far end and near end crosstalk. This “offsetting” between conductor pairs in a logical, methodological pattern to optimize electrical properties is an additional benefit associated with the rifled shaped separators with ladder-like sections.

[0030] According to one embodiment, the cable includes a plurality of transmission media with metal and/or optical conductors that are individually disposed; and an optional outer jacket maintaining the plurality of data transmission media in proper position with respect to the core. The core is comprised of a support-separator having a multi-anvil shaped profile that defines a clearance to maintain a spacing between transmission media or transmission media pairs in the finished cable. The core may be formed of a conductive or insulative material to further reduce cross-talk, impedance and attenuation.

[0031] Accordingly, the present invention provides for a communications cable, with a multi-anvil shaped support-separator, that meets the exacting specifications of high performance data cables and/or fiber optics or the possibility of including both transmission media in one cable, has a superior resistance to deformation during manufacturing and use, allows for control of near-end cross-talk, controls electrical instability due to shielding, is capable of 200 and 600 MHz (Categories 6 and 7) transmission with a positive attenuation to cross-talk ratio (ACR ratio) of typically 3 to 10 dB.

[0032] Moreover, the present invention provides a separator so that the jacket material (which normally has inferior electrical properties as compared with the conductor material) is actually pushed away from the electrical conductor, thus acting to again improve electrical performance (ACR, etc.) over the life of the use of the cable. The anvil-shaped separator, by simple geometric considerations is also superior to the “X” type separator in that it increases the physical distance between the conductor pairs within the same cable configuration, as shown in FIGS. 2 and 3.

[0033] Additionally, it has been known that the conductor pair may actually have physical or chemical bonds that allow for the pair to remain intimately bound along the length of the cavity in which they lie. The present invention describes a means by which the conductor pairs are adhered to or forced along the cavity walls by the use of grooves. This again increases the distance, thereby increasing the volume of air or other dielectrically superior medium between conductors in separate cavities. As discussed above, spacing between pairs, spacing away from jackets, and balanced spacing all have an effect on final electrical cable performance.

[0034] It is an object of the invention to provide a data/multi-media cable that has a specially designed interior support that accommodates conductors with a variety of AWG's, impedances, improved crush resistance, controlled NEXT, controlled electrical instability due to shielding, increased breaking strength, and allows the conductors, such as twisted pairs, to be spaced in a manner to achieve positive ACR ratios.

[0035] It is still another object of the invention to provide a cable that does not require individual shielding and that allows for the precise spacing of conductors such as twisted pairs and/or fiber optics with relative ease. In the present invention, the cable would include individual glass fibers as well as conventional metal conductors as the transmission medium that would be either together or separated in clearance channel chambers provided by the anvil-shaped sections of the core support-separator.

[0036] Another embodiment of the invention includes having a multi-anvil shaped core support-separator with a central region that is either solid or partially solid. This includes the use of a foamed core and/or the use of a hollow center of the core, which in both cases significantly reduces the material required along the length of the finished cable. The effect of foaming and/or producing a support-separator with a hollow center portion should result in improved flammability of the overall cable by reducing the amount of material available as fuel for the UL 910 test, improved electrical properties for the individual non-optical conductors, and reduction of weight of the overall cable.

[0037] Another embodiment includes fully opened surface sections defining the core clearance channels which extend along the longitudinal length of the multi-anvil shaped core support-separator. This clearance provides half-circular channel walls for each of the conductors/optical fibers or conductor pairs used within the cable. A second version of this embodiment includes a semi-closed or semi-opened surface section defining the same core clearance channel walls. These channel walls would be semi-circular to the point that at least 200 degrees of the potential 360 degree wall enclosure exists. Typically, these channels walls would include and opening of 0.005 inches to 0.011 inches wide. A third version of this embodiment includes either a fully closed channel or an almost fully closed channel of the anvil-shaped core support-separator such that this version could include the use of a “flap-top” initially providing an opening for insertion of conductors or fibers and thereafter providing a covering for these same conductors or fibers in the same channel. The flap-top closure can be accomplished by a number of manufacturing methods including heat sealing during extrusion of the finished cable product. Other methods include a press-fit design, taping of the full assembly, or even a thin skin extrusion that would cover a portion of the multi-anvil shaped separator. All such designs could be substituted either in-lieu of a separate cable jacket or with a cable jacket, depending on the final property requirements.

[0038] Yet another embodiment of the invention allows for interior corrugated clearance channels provided by the anvil-shaped sections of the core support-separator. This corrugated internal section has internal axial grooves that allow for separation of conductor pairs from each other or even separation of single conductors from each other as well as separation of optical conductors from conventional metal conductors. Alternatively, the edges of said grooves may allow for separation thus providing a method for uniformly locating or spacing the conductor pairs with respect to the channel walls instead of allowing for random floating of the conductor pairs.

[0039] Each groove can accommodate at least one twisted pair. In some instances, it may be beneficial to keep the two conductors in intimate contact with each other by providing grooves that ensure that the pairs are forced to contact a portion of the wall of the clearance channels. The interior support provides needed structural stability during manufacture and use. The grooves also improve NEXT control by allowing for the easy spacing of the twisted pairs. The easy spacing lessens the need for complex and hard to control lay procedures and individual shielding. Other significant advantageous results such as: improved impedance determination because of the ability to precisely place twisted pairs: the ability to meet a positive ACR value from twisted pair to twisted pair with a cable that is no larger than an ISTP cable; and an interior support which allows for a variety of twisted pair and optical fiber dimensions.

[0040] Yet another related embodiment includes the use of an exterior corrugated or convoluted design such that the outer surface of the support-separator has external radial grooves along the longitudinal length of the cable. This exterior surface can itself function as a jacket if the fully closed anvil-shaped version of the invention as described above is utilized. Additionally, the jacket may have a corrugated, smooth or ribbed surface depending on the nature of the installation requirements. In raceways or plenum areas that are new and no previous wire or cable has been installed, the use of corrugated surfaces can enhance flex and bending mechanical strength. For other installations, a smooth surface reduces the possibility of high friction when pulling cable into areas where it may contact surfaces other than the raceway or plenum. Mechanical integrity using an outer jacket such as depicted in FIGS. 2a, 2b, or 2c may be essential for installation purposes.

[0041] Alternatively, depending on manufacturing capabilities, the use of a tape or polymeric binding sheet may be necessary in lieu of extruded thermoplastic jacketing. Taping or other means may provide special properties of the cable construction such as reduced halogen content or cost and such a construction is found in FIG. 2c.

[0042] Yet another related embodiment includes the use of a strength member together with, but outside of the multi-anvil shaped core support-separator running parallel in the longitudinal direction along the length of the communications cable. In a related embodiment, the strength member could be the core support-separator itself, or in an additional related embodiment, the strength member could be inserted in the hollow center-portion of the core.

[0043] According to another embodiment of the invention, the multi-anvil shaped core support-separator optionally includes a slotted section allowing for insertion of an earthing wire to ensure proper and sufficient electrical grounding preventing electrical drift.

[0044] It is possible to leave the multi-anvil shaped separator cavities empty in that the separator itself or within a jacket would be pulled into place and left for future “blown fiber” or other conductors along the length using compressed air or similar techniques such as use of a pulling tape or the like

[0045] Additional embodiments to the invention include the use of rifled shape separators with ladder-like sections to provide similar crush resistance to the standard “X” supports. These rifled sections, however, have the additional feature that the center portion of the separator may include solid sections that can be adjusted in step-like increments such that conductor spacing can be controlled with a degree of precision. Specifically, the conductors can be set apart so that individual pairs or sets of pairs can be spaced closer or farther from one another, allowing for better power sum values of equal level far end and near end cross-talk. This “offsetting” between conductor pairs in a logical, methodological pattern to optimize electrical properties, is an additional benefit associated with the rifled shaped separators with ladder-like sections.

[0046] It is to be understood that each of the embodiments above could include a flame-retarded, smoke suppressant version and that each could include the use of recycled or reground thermoplastics in an amount up to 100%.

[0047] A method of producing the communications cable, introducing any of the multi-shaped core separators as described above, into the cable assembly, is described as first passing a plurality of transmission media and a core through a first die which aligns the plurality of transmission media with surface features of the core and prevents or intentionally allows twisting motion of the core. Next, the method bunches the aligned plurality of transmission media and core using a second die which forces each of the plurality of the transmission media into contact with the surface features of the core which maintain a spatial relationship between each of plurality of transmission media. Finally, the bunched plurality of transmission media and core are optionally twisted to close the cable, and the closed cable optionally jacketed.

[0048] Other desired embodiments, results, and novel features of the present invention will become more apparent from the following drawings and detailed description and the accompanying claims.

[0089] The following description will further help to explain the inventive features of the cable and the interior support portion of the cable.

[0090] FIG. 1a is a top-right view of one embodiment of this invention. The shown embodiment has an interior support shown as an anvil-shaped separator (110). The interior support anvil-shaped separator, shown in more detail in FIGS. 3 and 4, runs along the longitudinal length on the cable. The interior support anvil-shaped separator, hereinafter, in the detailed description, referred to as the “anvil-shaped separator”, has a central region (112) extending along the longitudinal length of the cable. The center region includes a cavity that runs the length of the separator in which a strength member (114) may be inserted. Channels 120, 122, 124, and 126 extend along the length of the anvil-shaped separator and provide compartments for conductors (130).

[0091] A strength member may be added to the cable. The strength member (114) in the shown embodiment is located in the central region of the anvil-shaped separator. The strength member runs the longitudinal length of the anvil-shaped separator. The strength member is a solid polyethylene or other suitable plastic, textile (nylon, aramid, etc.), fiberglass flexible or rigid (FGE rod), or metallic material.

[0092] Conductors, such as the shown insulated twisted pairs, (130) are disposed in each channel. The pairs run the longitudinal length of the anvil-shaped separator. While this embodiment depicts one twisted pair per channel, there may be more than one pair per channel. The twisted pairs are insulated with a suitable polymer, copolymer, or dual extruded foamed insulation with solid skin surface. The conductors are those normally used for optical or conventional data transmission. The twisted pairs may be bonded such that the insulation of each conductor is physically or chemically bound in an adhesive fashion, or an external film could be wrapped around each conductor pair to provide the same effect. Although the embodiment utilizes twisted pairs, one could utilize various types of insulated conductors within the anvil-shaped separator channels or cavities.

[0093] FIG. 1b is another embodiment that includes grooves on either the exterior surface of the separator or within the channels of the separator or both. The interior grooves within the channels of this embodiment are specifically designed so that at least a single conductor of a conductor pair can be forced along the inner wall of the groove, thereby allowing for specific spacing that improves electrical properties associated with the conductor or conductor pair. A cross section of this separator with channeled grooves is shown and discussed in a later figure.

[0094] FIG. 1c is yet another related embodiment that includes the use of an exterior corrugated design (160) such that the outer surface of the support-separator has external radial grooves along the longitudinal length of the cable. This exterior surface can itself function as a jacket if the fully closed anvil-shaped version of the invention as described above is utilized. Optionally, this corrugated version of FIG. 1c may also include the channeled grooves shown in FIG. 1b.

[0095] A metal drain wire may be inserted into a specially designated slot (140). The drain wire functions as a ground or earthing wire. It also serves to reduce material content and maybe applicable to each anvil-type separator.

[0096] The anvil-shaped separator may be cabled with a helixed configuration. The helically twisted portions in turn define helically twisted conductor receiving grooves within the channels that accommodate the twisted pairs or individual optical fibers.

[0097] The cable (200), as shown in FIG. 2a is a high performance cable capable of greater than 600 MHz and easily reaching 2 Ghz or greater. The cable has an optional outer jacket (210) that can be a thermoplastic, polyvinyl chloride, a fluoropolymer or a polyolefin, or a thermoset, with or without halogen free material as required by flammability, smoke generation, corrosivity, or toxicity, and electrical specifications as detailed above. Additionally, the jacket may be either corrugated (220) as in FIG. 2b or smooth/ribbed (210) depending on the nature of the installation requirements. Mechanical integrity using an outer jacket such as depicted in FIGS. 2a and 2b, may be essential for installation purposes.

[0098] FIG. 2b is another embodiment that includes grooves along the interior channels of the separator. The interior grooves within the channels of this embodiment are also specifically designed so that at least a single conductor of a conductor pair can be forced along the inner wall of the groove, thereby allowing for specific spacing that improves electrical properties associated with the conductor or conductor pair.

[0099] Over the anvil shaped separator optional polymer binder sheet or tape or sheets or tapes (230) that may be non-wovens such as polyimide, polyether-imide, mica, or other fire retardant inorganic tapes may be used as shown in FIG. 2c for circuit integrity cable. The binder is wrapped around the anvil shaped separator to enclose the twisted pairs or optical fiber bundles. The binder or tape itself maybe a laminated aluminum shield or the aluminum shield may also be included under the polymer binder sheet. The electromagnetic interference and radio frequency (EMI-RFI) shield is a tape with a foil or metal surface facing towards the interior of the jacket that protects the signals carried by the twisted pairs or fiber cables from electromagnetic or radio frequency distortion. The shield may be composed of a foil and has a belt-like shield that can be forced into a round, smooth shape during manufacture. This taped embodiment with shield may be utilized to control electrical properties with extreme precision. This shielded version is capable of at least 1 Ghz or higher frequency signal propagation. Each of the individual conductor pairs may themselves be individually shielded. A metal drain wire (240) may be inserted into a specially designated slot that then can be subsequently wrapped around the shield. The drain wire within the slot runs the length of the cable. The drain wire functions as a ground or earthing wire.

[0100] Use of the term “cable covering” refers to a means to insulate and protect the cable. The cable covering being exterior to said anvil member and insulated conductors disposed in grooves provided within the clearance channels. These grooves within clearance channels allow for proper insertion of conductors. Recent developments in communications cabling has shown that improvements in electrical properties can be accomplished if “worst” pair conductors are spaced such that they are physically further removed from other “worst pair” conductors. “Worst pair” refers to two conductors that are physically matched and can be helically twisted around each other such that electrical properties such as attenuation, crosstalk, and impedance properties are least favorable in comparison with other similarly paired conductors. Inevitably, during cable manufacture, at least one set of paired conductors exhibit these “worst pair” parameters and a major attribute of this invention is to space these “worst pairs” far from the better electrical transmission performing pairs. Parallel pair conductors with individual shielding can also be used to achieve the present invention.

[0101] The outer jacket, shield, drain spiral and binder described in the shown embodiment provide an example of an acceptable cable covering. The cable covering, however, may simply include an outer jacket or may include just the exterior surface (corrugated or convoluted with ribbed or smooth surfaces) of the anvil shaped interior support member.

[0102] The cable covering may also include a gel filler to fill the void space (250) between the interior support, twisted pairs and a portion of the cable covering.

[0103] The clearance channels formed by the anvil shaped interior support member of the present inventive cable design allows for precise support and placement of the twisted pairs, individual conductors, and optical fibers. The anvil shaped separator will accommodate twisted pairs of varying AWG's and therefore of varying electrical impedance. The unique circular shape of the separator provides a geometry that does not easily crush and allows for maintenance of a cable appearing round in final construction.

[0104] The crush resistance of the inventive separator helps preserve the spacing of the twisted pairs, and control twisted pair geometry relative to other cable components. Further, adding a helical twist allows for improving overall electrical performance design capability while preserving the desired geometry.

[0105] The optional strength member located in the central region of the anvil shaped separator allows for the displacement of stress loads away from the pairs.

[0106] FIG. 3a is a horizontal cross-section of a preferred embodiment of the anvil-shaped separator. The anvil-shaped separator can be typically approximately 0.210 inches in diameter. It includes four channels (300, 302, 304, and 306) that are typically approximately 0.0638 to 0.0828 inches in diameter. The channel centers are 90 degrees apart relative to the center of the separator. Each channel is typically approximately 0.005 inches from the channel across from it, and each channel is approximately 0.005–0.011 inches apart from its two nearest-neighboring channels at their closest proximity. Inserted in the channels is one set of twisted pairs (310, 312, 314, and 316) with the option for adding twisted pairs to each channel denoted by dashed circles. In a preferred embodiment, each channel has typically a 0.037-inch opening along its radial edge that allows for the insertion of the twisted pairs. This embodiment also includes a cavity in the center of the anvil-shaped separator for a strength member (320). Additionally, there is a slot for a drain or earthing wire (330). The exploded view of FIG. 3a also indicates the use of an interior slotted rifled section or sections (332) that allows for less bulk material based on overall depth of the slots of the rifled section, improves electrical characteristics as described above regarding worst pair conductors (allowing for more air around each insulated conductor or pair), and physically binds the pairs together so that each pair has semi-permanently fixed position. As shown in the other exploded view (334), the individual conductor may compress against the solid or foamed slotted rifled surface to ensure the semi-permanently fixed position.

[0107] FIG. 3b is another embodiment of the anvil-shaped separator. The anvil-shaped separator includes a single flap-top (340, 342, 344, and 346) that is initially in an open position to allow the twisted pairs to be inserted into the channels. In FIG. 3c the flap-tops are in the closed position (350, 352, 354, and 356) where the flap-top fits into a recessed portion of the separator for closure. The flap-tops are self-sealing when heat and/or pressure is applied, such that elements within the channels can no longer be removed from the separator and such that the channels containing the twisted pairs are enclosed. The flap-top is shown in more detail in FIG. 3d.

[0108] FIG. 3e is another embodiment of the anvil-shaped separator. The anvil-shaped separator includes a single flap-top (380, 382, 384, and 386) that is depicted in the closed position. When in the closed-position, the flap-top overlaps the outer portion of the separator. The amount of overlap required will depend on several design and manufacturing factors and the shown embodiment is only intended as one example of the overlap required. The flap-tops are self-sealing when heat and/or pressure is applied, such that the elements within the channels can no longer be removed or displaced from the separator and such that the channels containing twisted pairs are enclosed. The flap-top is shown in more detail in FIG. 3f.

[0109] Another embodiment of FIG. 3 includes all of the aforementioned features of FIG. 3 without the drain wire or drain wire slot, but may include the center hole for strength members. Use of a center hole is also important in that it reduces the mass required for the spacing. It has been shown and reported in prior art journals and publications that the total mass of the organic components of the cable is directly proportional to flame spread and smoke generation. As mass is reduced, the probability that the cable will pass more stringent flame testing (such as U.L. 910/NFPA 262/IEC 60332-3B₁/IEC 60332-3B₂ as previously described) significantly increases.

[0110] A further embodiment of FIG. 3 includes all the aforementioned features of FIG. 3 without the center hole for strength members and without the drain wire or drain wire slot.

[0111] FIG. 4a is a horizontal cross-section of a preferred embodiment of the anvil-shaped separator that is identical to FIG. 3b but has a pair of overlapping section instead of the single overlapping section of FIG. 3b and may include optional “stepped” or “rifled” grooves that exist along the inner circumference of the clearance channels. These grooves can be larger in diameter than pictured and used to improve spacing of the “worst pair” conductors as described earlier. These rifled clearance channels can be used to “squeeze” the conductors or conductor pairs into the interstitial openings creating a more permanent positioning that will enhance the electrical characteristics of the final cable assembly. If properly positioned during the “twinning” and subsequent forming of the cable, the forced positioning of the conductors in the rifled sections will improve signal performance. The anvil-shaped separator includes double flap-tops (440,442, 444, and 446) that are initially in an open position to allow the twisted pairs to be inserted into the channels. In FIG. 4b (exploded view FIG. 4c) the flap-tops are in the closed position (450, 452, 454, and 456). The flap-tops are again self-sealing in the presence of heat and/or pressure and the channels containing the twisted pairs are subsequently enclosed. The flap top is shown in more detail in FIG. 4c. Another embodiment of FIG. 4 includes all of the aforementioned features of FIG. 4 without the drain wire or drain wire slot, but includes the center hole for strength members. A further embodiment of FIG. 4 includes all the aforementioned features of FIG. 4 without the center hole for strength members and without the drain wire or drain wire slot.

[0112] FIG. 3d depicts the single flap-top in enlarged detail, and FIG. 4c depicts the double flap-top in enlarged detail. The single flap-tops (360 and 390) and the double flap-top (410) enclose the wires or cables within channels created by the separator. During manufacturing, the flap-top is in the opened position and closes as either pressure or heat or both are applied (normally through a circular cavity during extrusion). Optionally, a second heating die may be used to ensure closure of the flap-top after initial extrusion of the separator or cable during manufacture. Another possibility is the use of a simple metal ring placed in a proper location that forces the flap-top down during final separator or cable assembly once the conductors have been properly inserted into the channels. The metal ring may be heated to induce proper closure. Other techniques may also be employed as the manufacturing process will vary based on separator and cable requirements (i.e. no. of conductors required, use of grounding wire, aligrinent within the channels, etc.). In one embodiment the single flap-top (360) is secured to a recessed portion of one side of an opening of the cavity of the separator (365), and closure occurs when the unsecured, physically free end is adjoined to and adhered with the other end of the outer surface of the channel wall. In another embodiment the single flap-top (390) is secured by overlapping and adhering the unsecured end to the outer surface of the separator (395), thereby, enclosing the channel. The double-flap top arrangement requires that both flap-top ends physically meet and eventually touch to secure enclosure of the existing cavity (460) formed by the separator (470).

[0113] FIG. 5 is a cross-section of another embodiment of the flap-top anvil-shaped separator. Each channel is enclosed by double flaps that can be sealed via heat and/or pressure (510, 512, 514, and 516). Each channel contains at least one fiber (520, 522, 524, and 526) that runs the length of the cable. More than one fiber may be included in each channel if necessary. The separator also includes a slot for a drain or earthing wire (530). For applications such as multimedia cables, the application may have one or more twisted pair, one or more fiber optic conductors, or coaxial cables within the clearance channels of the anvil separators.

[0114] FIG. 6 is a cross-section of a cable that contains four anvil-shaped separators (600, 602, 604, and 606) within a larger anvil-shaped separator (610). The larger separator contains a cavity in the center of the separator for a strength member (620). Each of the smaller separators contained within the larger anvil-shaped separator has four channels (630, 632, 634, and 636). As shown, each of these channels contains a twisted pair within this embodiment (640, 642, 644, and 646). This embodiment allows for a total of sixteen twisted pairs to be included in one cable.

[0115] FIG. 7a is a cross-section of a cable that contains six symmetrical rifled cross separators (700, 701, 702,703, 704, 705) within a larger anvil shaped separator (710). The larger separator contains a optional hollow cavity in the center of the separator for an optional strength member (720). Each of the smaller separators contained within the larger anvil-shaped separator has four channels (730, 732, 734, and 736). Within each of these channels is one twisted pair (740, 742, 744, and 746). This embodiment allows twenty four twisted pairs to be included in one cable.

[0116] FIG. 7b are cross-sections of a cable that contains rifled six anvil-shaped separators (750, 751, 752, 753, 754, and 755) within a larger anvil-shaped separator (710). The larger separator contains an optional hollow cavity in the center of the separator for a either a strength member or an additional conductor pair (725) which is accessed via a slit (726) which can be forced opened during manufacture. Each of the smaller separators contained within the larger anvil-shaped separator has four smooth or rifled channels (780, 782, 784, and 786). Within each of these channels is one twisted pair (760, 762, 764, and 766). This embodiment allows twenty four twisted pairs to be included in one cable. Feature (750) is an optional wired slot for a drain wire with or without a shield.

[0117] FIGS. 8a and 8b depict a cross-section and additional embodiment of an anvil-shaped separator which has been substantially trimmed such that the each edged end of each anvil is removed (800 and 802) to reduce weight resulting in enlarged channel openings (804). FIG. 8b depicts the cross-section with optional drain wires within each solid and trimmed anvil section (810, 812, 814, and 816) as well as optional rifled slots within each clearance channel and optional asymmetric conductor pair offset due to the skewed elongated axis.

[0118] FIG. 9 is a cross-section and additional embodiment of a separator where the dual lobed ends of the anvil are minimized (900 and 902) such that an even further reduction in weight, enlarged channel openings (904) and enlarged channel girth are provided. FIG. 9 includes earthing or drain wire slots (910, 912, 914, and 916).

[0119] FIG. 10 is a cross-sectional end view of a large cable spacer separator that itself separates six (6) anvil shaped separators as described in detail and shown in FIGS. 1 and 2 and very similar to the design shown as FIGS. 7(a) and 7(b). This separator has an optional center (1000) orifice that allows for reduction of mass and thereby reduction of flame spread and smoke generation in, for example UL 910/NFPA 262/IEC 60332-3B₁/ IEC 60332-3B₂ and associated flame testing as previously described. The entire center section (with the center 1000 orifice or without it) could be either solid or foamed or a combination using a skinned solid surface over a foamed core. This design allows for six solid anvil shaped cores (1001) with four clearance channels for conductor pairs. In addition, the large cable spacer separator includes six special “Y” shaped channel spacings (1002–1007) at the outer edges that allow for a fifth conductor pair within these channels. The fifth conductor pairs (1008) are optional in that some or none of the “Y” shaped channel spacings (1002–1007) may be filled. Each of the solid anvil cores (1001) also may optionally contain a center orifice (1009). Each of the conductors consist of an inner solid metal portion (1011, 1015, 1018, and 1021) and an outer insulation (1010, 1014, 1017, and 1020) covering the solid metal portion of the conductors or conductor pairs that are held within each of the four clearance channels (1012, 1016, 1019, and 1022) formed by the six anvil shaped separators cores (1001). In addition to the clearance channels (1012) provided for the conductors or conductor pairs, there all exists an optional specially designed slot (1013) for a metal drain wire that provides proper grounding or earthing of the conductors within the cable for instances where an aluminum mylar shield may be used.

[0120] FIG. 11 is a cross-sectional view of a optionally skewed or asymmetrical “maltese cross-type” cable spacer separator. It is skewed in the sense that along one axis of symmetry in a two-dimensional plane, the tip-to-tip length is longer than along the other. This spacer provides two relatively larger width blunt tipped ends (1100) and two relatively smaller width tipped blunt ends (1102). The distance between a larger width blunt end tip and a smaller width blunt end tip along the longer axis of symmetry provides two skewed channels (1104) for “worst” pair conductors. These pairs are the ones determined to have the least desirable electrical properties and thus are intentionally spaced further apart from each other. The better performing electrical pairs are contained in two skewed channels (1106) formed between a larger width blunt end tip (1100) and a smaller width blunt end tip (1102) along the shorter axis of symmetry. In this manner the “worst pair” channels (1104) are adjacent to the “better pair” channels (1106) so that the influence of the poorest electrical performing conductors or conductor pairs (1110) are insulated from another poorest or poorer performing electrical pair (1110). Best or better conductor pairs (1112) would be provided in the better pair channels. As previously alluded to, distance, and the presence of air are the two controllable parameters used in the present invention to reduce electrical property deterioration due to “worst pair”—“worst pair” interaction. A center (optional) orifice (1108) is also provided which would allow for reduction of weight of material and better flammability and smoke generation properties as previously described.

[0121] FIG. 12 is a cross-sectional view of an optionally skewed “maltese cross-type” cable spacer separator with “rifled” sections along the outer perimeter of the spacer separator. It optionally skewed in the sense that along one axis of symmetry in a two-dimensional plane, the tip-to-tip length is longer than along the other. This spacer provides four equi-widthed blunt tipped ends (1200).The rifled sections as shown in FIG. 12b contain interstitial stepped optionally rifled spacers (1201) extending from near the blunt tipped ends toward channels (1205) formed for single or paired conductors that are provided such that the conductor or conductor pairs will be “squeezed” into a portion of the rifled section where some traction or friction within these interstitial stepped spacer rifled sections will control spacing and movement during the entire cabling operation. In this manner, again “worst pair” spacing can be achieved. A center (optional) orifice (1204) is also provided which would allow for reduction of weight of material and better flammability and smoke generation properties as previously described.

[0122] FIG. 13 A is a cross-sectional view of a diamond shaped cable spacer separator that is solid (1300) and provides for four semi-circular channels (1310) formed by curved surfaces of the diamond shaped spacer for conductors. The solid diamond shaped spacer has curved ends that converge at each of four tips (1320) which designate the beginning or ending of the channels. Individual conductors (1325) would be preferably placed in each of the channels for pair separator. Alternatively, conductor pairs could also be separated using this design and technique.

[0123] FIG. 13 B is a cross-sectional view of a diamond shaped cable spacer separator that has a hollowed center circular orifice section (1330) and provides for four semi-circular channels (1310) formed by curved surfaces of the diamond shaped spacer for conductors. The solid diamond shaped spacer has curved ends that converge at each of four tips (1320) which designate the beginning or ending of the channels. Individual conductors would be preferably placed in each of the channels for pair separator. Alternatively, conductor pairs could also be separated using this design and technique.

[0124] FIG. 13 C is a cross-sectional view of a diamond shaped cable spacer separator that has two triangular hollowed center sections, one of which is an upright equilateral triangular hollowed orifice (1340) and the other of which is a downward-facing equilateral triangular orifice (1345) and provides for four semi-circular channels (1310) formed by curved surfaces of the diamond shaped spacer for conductors. The solid diamond shaped spacer has curved ends that converge at each of four tips (1320) which designate the beginning or ending of the channels. Individual conductors would be preferably placed in each of the channels for pair separator. Alternatively, conductor pairs could also be separated using this design and technique.

[0125] FIG. 13 D is a cross-sectional view of a diamond shaped cable spacer separator that has a diamond shaped hollowed center orifice section (1350) and provides for four semi-circular channels (1310) formed by curved surfaces of the diamond shaped spacer for conductors. The solid diamond shaped spacer has curved ends that converge at each of four tips (1320) which designate the beginning or ending of the channels. Individual conductors would be preferably placed in each of the channels for pair separator. Alternatively, conductor pairs could also be separated using this design and technique.

[0126] FIG. 14 is a cross-sectional view of a pendulum-like shaped cable spacer separator with a circular-disc like pendant portion (1400) that is either in the center of the pendulum-like shaped separator or is optionally skewed to an elongated rectangular shaped end (1410). This separator does not form specific channels for conductors or conductor pairs, however the circular-disc like portion (1400) provides a device which allows for proper spacing of better or worse performing electrical pairs by placing this circular-disc in a specific location. The circular-disc (1400) includes an optional center hollow orifice portion (1420), again to reduce material loading which should enable certain cable constructions to pass stringent flame and smoke test requirements.

[0127] FIG. 15 is a cross-sectional view of a pendulum-like shaped cable spacer separator with an elliptical-disc like pendant portion (1500) that is either in the center of the pendulum-like shaped separator or is optionally skewed to an elongated rectangularly shaped end (1510). This separator also does not form specific channels for conductors or conductor pairs, however the elliptical-disc like portion (1500) provides a device which allows for proper spacing of better or worse performing electrical pairs by placing this elliptical-disc in a specific location. The elliptical-disc (1500) includes an optional center hollow orifice portion (1520), again to reduce material loading which should enable certain cable constructions to pass stringent flame and smoke test requirements.

[0128] FIG. 16 is a cross-sectional view of a pendulum-like shaped cable spacer separator with a diamond-disc pendant portion (1600) that is either in the center of the pendulum-like shaped separator or is optionally skewed to an elongated rectangularly shaped end (1610). This separator forms more specific channels for conductors or conductor pairs (1625) than that of FIGS. 14 and 15, and the diamond-disc like portion (1600) additionally provides a device which allows for proper spacing of better or worse performing electrical pairs by placing this diamond-disc in a specific location. The diamond-disc (1600) includes an optional center hollow orifice portion (1620), again to reduce material loading which should enable certain cable constructions to pass stringent flame and smoke test requirements. The design and function of the separator of FIG. 16 is similar to that shown in FIGS. 13 A–13 D with the additional feature of the horizontal separator bar that restricts movement of the conductors in the vertical direction during cabling and subsequent handling.

[0129] FIG. 17 is a cross-sectional view of a pendulum-like, dual-lobed shaped cable spacer separator with a diamond-shaped pendant portion in the center that can be optionally skewed to one end and with lobed end portions (1700). Channels for conductors (1725) are formed by curved elongated rectangular portions (1710) of the dual-lobed pendulum-like shaped separator.). This separator forms more specific channels for conductors or conductor pairs (1725) than that of FIGS. 14 and 15, similar to that of FIG. 16, and the diamond-shaped pendant portion additionally provides a device which allows for proper spacing of better or worse performing electrical pairs by placing this diamond-shaped pendant in a specific location. The diamond-shaped pendant section includes an optional center hollow orifice portion (1720), again to reduce material loading which should enable certain cable constructions to pass stringent flame and smoke test requirements.

[0130] FIG. 18 is a cross-sectional view of a rifled and symmetrically balanced cross cable spacer separator (1800) that is comprised optionally of a solid, foamed or soliwd skin over a foamed core as described earlier in the present specification and again for FIG. 18. The rifled cross separator also is comprised of four “tipped” ends that have key-like features (1810). The rifled cross separator provides clearance channels for conductors or conductor pairs that may or may not be separately insulated (1825) where each conductor or conductor pair includes an outer insulation material (1830) and an inner section portion of the conductor (1835). As for most of the prior separator constructions, a hollow orifice in the center (1820) is optional again for the purpose of material reduction loading.

[0131] FIG. 19 is a cross-sectional view of a dual drill-bit shaped cable spacer separator (1900) or “mirrored battleship” shape that is comprised optionally of a solid, foamed or solid skin over a foamed core as described earlier. If one were to split this separator along its central horizontal axis, the top and bottom portions would be mirrored images of each other in that the bottom portion would appear as a reflection of the top portion in much the way a battleship would be reflected by floating in a still body of water. Along the top portion of the separator, there is an ascending stepped section (1905) upon which exists a key-like shaped section (1910) that includes a double key-way inward protruding portion (1911) and a double key-way outward protruding portion (1912) of the separator. Along the bottom portion of the separator, there is a symmetrical (with the top portion) descending stepped section (1905) which includes the same shaped key-like section (1910) with inward protruding portions (1911) and outward protruding portions (1912) that exist under the bottom stepped section (1905).

[0132] This separator again provides at least a four quadrant set of clearance channels for conductors or conductor pairs with an optional outer film (1930) and with conductors that have both an outer insulation material (1940) and an inner conductor material (1945) for each individual conductor or conductor pair. There is a center hollow portion (1910) as part of the stepped (1905) portion that is also shaped in a circular fashion to again achieve material reduction for cost, flammability and smoke generation benefits.

[0133] FIG. 20 is a cross-sectional view of a “staggered rifled cross” shaped cable spacer separator (2000) that is comprised optionally of a solid, foamed or solid skin over a foamed core. As in the spacer of FIG. 20, there is at least one upward protruding sections (2005) near the center portion of the staggered rifled cross separator along the lateral or horizontal direction that are longer than such subsequent upward protruding sections in the same direction. There is also at least one laterally protruding section (2006) near the center portion of the staggered rifled cross separator along the lateral or horizontal direction that is longer than any subsequent laterally protruding section in the same direction. In addition, there are inwardly intruding sections near the center portion of the spacer (2007) along the vertical and lateral or horizontal directions of the separator as well as laterally protruding sections (as many as four) (2008) that may exist near the center portion of the staggered rifled cross separator. Inwardly intruding sections are also located near the tipped portions of the separator (2009)—as many as four may exist. At the same tipped end portion, there may be inverted ends (2010). This entire geometry is configured to ensure that “worst pair” electrical conductors are spaced in a staggered arrangement to ensure that little or no influence or synergism can occur between the electrically worst two pairs or electrically worst individual conductors. The rifled arrangement allows for squeezing the conductors into the interstices of each of four quadrants with optional outer jacket or film insulation (2030) for the conductor pairs which include an outer insulation section (2040) and an inner conductor section (2045). The central portion of the separator may also include a hollow orifice (2120).

[0134] FIG. 21 A is a cross-sectional view of an asymmetric cross, where each of four quadrants formed by the cross to make clearance channels are formed by either vertical or horizontal sections along an axis of the cross with varying widths. Here, the left side horizontal member (2110) is narrower in width than that of the right side horizontal member (2120). Similarly, the vertical member (2130) extending in an upward direction is narrower in width than that of the other vertical member (2140). FIG. 21 B is completely analogous to FIG. 21 A except that the asymmetric cross in this cross-sectional view includes rifled or “saw-blade” like members as shown previously. In this figure, section (2150) is narrower than section (2160) along the horizontal axis, and section (2170) is narrower than section (2180). The “teeth” of the saw-blade are described in detail with FIG. 22 below.

[0135] FIG. 22 is a cross-sectional view of a saw-blade type separator (2200) that may be, in fact, a semi-rigid thermoplastic or thermoset film with “serrated” or rifled section along the top and bottom portions of the horizontal axis. The teeth that form serrated edges may be shaped in several ways, two of which are shown in the expanded view of the same figure. Along either the top or bottom portion of the separator blunt undulating sections may be used (2210) or other shapes such as the “u” or “v” grooved sections (2220). It should be understood that the teeth may be used in any combination desired, based on the need of the cable manufacturer.

[0136] FIG. 23 A is a cross-sectional view of a symmetrical “Z” or angle-iron shaped type separator (2300) that also may be a semi-rigid thermoplastic or thermoset film. As shown, the separator is symmetric in that both horizontal sections (2310) and (2320) are of the same length and evenly spaced apart by the central vertical section (2330). The separator could also be asymmetric in that either of the horizontal sections could be extended or shortened with respect to one another. Also, the vertical section length could be adjusted as needed for electrical specification requirements. This separator is provided primarily for 2 conductor pair (2340) to be inserted in the clearance channels provided. FIG. 23 B is also a symmetrical “Z” or angle-iron shaped type separator with the addition, in this cross-sectional view, of rifled or “saw-blade” like members as shown previously. In this figure, sections (2350) and (2360) along the horizontal axis can be the same length or arbitrarily different lengths—resulting in an asymmetric shape. The central vertical section (2370) and associated saw-blade like teeth can also be lengthened or shortened as necessary. The “teeth” of the saw-blade are described in detail in FIG. 22 and the same blunt undulating, “u” or “v” shaped grooves can be used for this separator as well. This separator is provided primarily for 2 conductor pair (2380) to be inserted in the clearance channels provided.

[0137] It will, of course, be appreciated that the embodiment which has just been described has been given simply by the way of illustration, and the invention is not limited to the precise embodiments described herein; various changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.