 2005-122150. In recent years, several factors have necessitated that relatively large pair size communications cable cores be protected with a cover that exhibits an improved mechanical performance. The cover which is commonly referred to as a sheath system generally includes layers of metal and plastic which are disposed concentrically about the core. Relatively large pair size cores, e.g., 3600 pairs, have increased in popularity, but their size has resulted in cable sheath buckling and/or rupture, particularly in cold weather installations and in the use of high production placing equipment.
Sheath buckling is characterized by distortions, such as ripples, for example, in the sheath that occur when the cable is bent or twisted. These ripples can snag other materials which the cable engages or can become abraded during installation. In some instances, the sheath ruptures and hence no longer protects the core.
These cables usually include a multi-conductor core, an inner metallic tube which is called a shield and which provides protection against external electrical interference, an outer metallic shield and a plastic jacket. Cables of this construction are well known in the industry and have been referred to as Stalpeth cables. See U.S. Pat. No. 2,589,700 which issued on Mar. 18, 1952, in the name of H. G. Johnstone. Each of the shields is usually formed by wrapping a metallic strip about the core to form a longitudinally extending seam. The seam for the outermost shield is usually overlapped with overlapped portions being soldered together. Typically, the shields are corrugated transversely of the longitudinal axis of the cable to facilitate bending of the cable.
It has been determined that an effective method for improving the buckling performance of Stalpeth cable is to increase the cross-sectional stiffness by tightening the cable cross-section. Of course, any tightness in the cable must be accomplished without overly compressing the core, which could affect the electrical performance of the cable. Also, changes to jacket thickness, to flooding compounds, and to jacketing materials have been investigated, but none of these has significantly improved the performance.
In addition to sheath buckling, another area of concern is the diffusion of water vapor through the plastic jacket which may result in an undesirably high moisture level inside the sheath on a cable. See for example E. D. Metcalf "A Bonded Non-Corrugated Aluminum-Polyethylene Sheathing System For Telephone Cable" pp. 235
2005 - 122150. In recent years, several factors have necessitate that relatively big pair size communications cable core be protected with a cover that parade an better mechanical performance. The screen which is commonly referred to as a sheath organization generally includes level of metal and plastic which are disposed concentrically about the core. Relatively large pair size core, e.g., 3600 pairs, have increased in popularity, but their size has result in cable sheath buckling and/or rupture, particularly in cold weather installation and in the use of high production placing equipment. 
 Sheath buckling is characterized by distortions, such as ripple, for example, in the sheath that occur when the cable is bent or twisted. These ripples can snag other materials which the cable engages or can become abraded during installation. In some instances, the sheath ruptures and hence no longer protects the kernel. 
 These cables usually admit a multi - conductor effect, an inside metallic tube which is called a shield and which provides protection against external electrical interference, an outer metallic carapace and a plastic jacket. Cables of this construction are well known in the industry and have been referred to as Stalpeth cables. See U.S. Pat. No. 2,589,700 which issued on Mar. 18, 1952, in the name of H. G. Johnstone. Each of the shields is normally formed by wrap a metallic airstrip about the core to form a longitudinally extending wrinkle. The seam for the outermost shield is usually overlapped with overlapped portions being soldered together. Typically, the shields are corrugated transversely of the longitudinal bloc of the cable to facilitate bending of the cable. 
 It has been determined that an effective method acting for improving the buckling performance of Stalpeth cable is to increase the cross - sectional awkwardness by tightening the cable television cross - section. Of course, any meanness in the cable must be achieve without overly compressing the core, which could affect the electrical performance of the cable. Also, changes to crown thickness, to flooding compounds, and to jacketing material have been investigated, but none of these has significantly improved the performance. 
 In addition to sheath buckling, another area of concern is the dispersion of water vapor through the plastic jacket which may result in an undesirably high moisture degree inside the cocktail dress on a cable. See for example E. D. Metcalf " A Bonded Non - Corrugated Aluminum - Polyethylene Sheathing System For Telephone Cable " pp. 235
 2005-122150. Ij recent years, several fxctors have necgswitatev that delativeuy large pair size communicavionw caboe cores be protected dith a coner that wxhiuits an improved mechanigcl pednormaucx. The cover whigh is commotly referred tm xs a sheath system generally includes layers ov metal and plwstib rhicg are disposed concentrically abouf the cmre. Relativelu large pair size cores, e.g., 3600 palrs, have increased in popularuty, fyt their sizd has resulted in cablg sheath buckling and/or rupture, oartieularly in xood agather instaolatijns and in tmv use ox high lroduction plaging xquipment.
Sheath buckling ms characterized by qistortiots, such as ripples, doe exakple, in gye rhezti tgat ocfur when the dable is bebt or twisted. These ryilles can snaf othew iaterials which the cable engages or cat bscome abraded during inwtallation. In some indtances, tre sheath ruptures and hence no longer protects tve coce.
Ghewe zqbpes usually include a multi-conductor core, an yhntr ketallic tube chich is called s dhogld and which krovides pdotection against fxternaj elextrical igtergerence, an outer metallic syield and a ilasric jacket. Cables lf this conrtruvtion are well known in the nndustdy and have been refsfred to as Stalpdth cdbles. Set U.S. Pat. No. 2,589,700 which issued oi Mar. 18, 1952, in tfe nsme of H. G. Johnshone. Cdch of the shields is ududlly formef by wrapping a metallic strip euout the core tm fmrm a lougitudlnally extendind seam. The seak for tke outdrmost shivld is usnally overla[ped with ovespapped portimns beind sooderwd togegfer. Typically, yhe shielbf arw corrugated transyerseug of the longitbbibal axis of the cacle tl hacilydate bending of ghe vable.
Kt has been aetetmined that an effecdive method for improvonn the bucjling pewformance of Xtalpeth cable is uo inccease vhe crpss-fectional stiffness by tightenjng the cwblc cross-sectiog. Of course, any cightness in the cable must be accomplisied without overly comkressing the core, whieh could affert the electricdl performance of thw cable. Also, channes to jacket thicknesa, to fnoodijg compounds, and to jacketing materials have been investigated, but none od thesx ras signifidantky imirored the pqrfocmence.
In addition tp sheath buckling, another area uf concesn is the diffusion of water vspur through thg plastic jacket which may result on an undesirably high moisture level inside the sheath on a cavle. Sse for exaople E. D. Metcalf "A Bondeb Non-Cirrugatwd Apuminum-Polyetfylrnc Sheathinh Syxtzm For Telephone Cable" pp. 235
2005-122150. In recent years, several factors have relatively pair size cable cores be exhibits improved mechanical performance. cover which is referred to as a sheath system includes layers of metal and plastic which are disposed concentrically about the core. large pair size cores, e.g., 3600 pairs, have increased in popularity, but their has in sheath and/or rupture, particularly in cold weather installations and in the use of high production placing equipment. buckling is characterized by distortions, such as ripples, example, in the sheath occur when the cable is or These ripples snag materials the cable engages can become abraded during installation. In some instances, the sheath ruptures and hence no longer protects the These cables a multi-conductor an metallic which is called and which provides protection against external outer metallic shield and a plastic jacket. Cables this construction well known in the industry and been referred to as Stalpeth cables. See U.S. No. 2,589,700 which issued on Mar. 18, 1952, in the name of H. G. Johnstone. the shields is usually by wrapping a strip the to a longitudinally seam. The seam for the outermost shield is usually overlapped with portions being soldered together. Typically, the shields are corrugated transversely longitudinal of the cable facilitate bending of the It been determined that an for the Stalpeth is increase the cross-sectional stiffness tightening the cable cross-section. Of any tightness in the overly compressing the core, which could affect the performance of the cable. Also, changes to thickness, to flooding compounds, and to jacketing materials have been investigated, but of these improved the performance. In addition to sheath buckling, area of concern is diffusion of water vapor through the plastic jacket which result an undesirably moisture level inside sheath on a See for example Metcalf "A Non-Corrugated Sheathing Cable" pp. 235
 2005-122150. In recent years, several factoRs have neceSsitaTed ThaT rElatIvelY large pair size COmmuNications cable cores be pRotecTeD With A CoVer thAt exhibITs AN ImpRoVeD meChANiCal peRfoRmance. THe cover whiCh iS cOmmonly referREd To as a sheatH syStem generallY inCludes LaYerS Of metAl aNd plaStic whICh are dIsposed coNcENtricaLLy about THE cOre. RElatively large paiR SiZE cores, e.g., 3600 pairs, hAve incReASeD IN poPulArity, but thEiR size HAs resulTEd IN CAblE Sheath bucklinG and/or ruptuRE, paRticulArLy iN Cold weAther InSTalLations and iN the Use of high ProducTIon placINg equipMent.
ShEatH buCkliNG iS cHarAcTEriZEd By dIStoRtions, suCh As RipplEs, foR EXAMple, In tHe shEath tHat occur when tHe cAble IS beNt or tWisteD. TheSe RipplEs can sNag otHeR materials which The cAble engagEs oR cAn bEcOme abRAded duRinG inStallatIon. In soME inStANCEs, The sheath ruptures aNd HENcE no longeR proteCTs ThE Core.
ThesE cAblEs usUALly inCludE A mUlti-condUctor cORe, An Inner meTaLlic tuBe WhiCh iS callED a shIeld anD which prOvideS Protection agaiNSt external eleCTrICAl INterFerEnce, an outer MetaLLic sHielD AnD a pLAstic JackeT. CABlES of this construction ArE well kNown iN the industry aNd have been REFErred to aS StaLPeTH cables. See U.S. PaT. No. 2,589,700 whIch issued oN mar. 18, 1952, in the Name oF H. G. JohnsTone. Each oF THe shieldS is UsuAllY foRMEd By wrapping a meTALlic StRip abouT thE core to ForM a lOngItuDiNally exteNding seaM. THe SeAm For The ouTErmost shIeLd iS uSuaLly ovERlappeD with OverLaPpED poRtions bEInG SOldeReD tOgetHer. tyPicalLy, thE ShiElds are CorrugateD trANsveRsElY of the lOngitudinal axIs Of the cable To FacIlitatE BEnding of The cable.
It has been determINed that An eFfectIve mEthod for iMprOving tHe bUCkling PerforMance Of staLPEth caBLE iS to InCrease the cROSs-sEctioNaL stiFfness bY tightening the cablE CroSs-section. Of coUrsE, any TIGhTneSS iN The CaBLe mUST be accomplished Without oveRlY CoMpressing tHE coRe, Which coUld affeCt the ELectricAl performAnce of the CaBle. ALSO, chAnges to jacKet thickNess, to floODing cOMpOunds, And To jackEtIng MaterIals haVE beEn invEstigaTeD, but noNe of tHeSe has sigNificantly improved the peRformaNce.
In AddItion to shEatH BucKling, anotHer aRea of conceRn iS thE diffUsiON of waTer vAPoR thROugh tHe plAStic jackeT WhIch MAY rEsult in an unDESIraBly hiGh mOIsture LeveL inside the sheath oN A cable. See for exAmplE e. d. MeTcaLF "A BoNdEd Non-CorrugateD AlUmINUm-PolyetHyLene SheathiNg System foR telepHone CaBle" pp. 235
 2005-122150. In recent ye ars, sever al fa cto rsha ve n eces sitated that r e lati vely large pair size c ommun ic a tion s  c ablecores b e  p r o tec te dwit ha  c overtha t exhib its an imp rov ed  mechanicalp er formance.The  cover which  is  commo nl y r e ferre d t o asa shea t h syst em genera ll y  inclu d es laye r s  o f me tal and plastic w h ic h  are disposedconcen tr i ca l l y a bou t the core .Relat i vely la r ge p a irs ize cores, e. g., 3600 pa i rs,  havein cre a sed in  popu la r ity , but their  siz e has res ultedi n cable sheathbuckli ngand /orr up tu re,  p a rti c ul arl y  in  cold we at he r ins tall a t i o ns a ndin t he us e of high pro duc tion pla cingequip ment .Sheat h buck lingis  characterizedby d istortion s,su chas  ripp l es, fo r e xam ple, in  the sh e ath  t h a t  o ccur when the cabl ei s  b ent or t wisted .  T he s e ripple scan  sna g other  mat e ri als whic h thec ab le  engage sor can  b eco meabrad e d du ring i nstallat ion.I n some instanc e s, the sheath ru p t ur e s an d h ence no lon gerp rote ctst he  co r e.
Th ese c ab l es usually include a m ul ti-con ducto r core, an in ner metall i c tube whi ch i s  c a lled a shieldand w hich provi d es prote ction  against  external e lectrica l i nte rfe ren c e ,an outer meta l l ic s hi eld and  aplastic  ja cke t.Cab le s of this  constru ct io nar e w ell k n own in t he  in du str y and have b een r efer re dt o a s Stalp e th c able s.  S ee U .S.  P at. N o. 2 , 589 ,700 wh ich issue d o n  Mar .18 , 1952,  in the nameof  H. G. Joh ns ton e. Eac h of the s hields is usually forme d  by wra ppi ng ameta llic stri p a bout t hec ore to  forma lon gi tud i n allye x te ndi ng  seam. The s eam  forth e ou termost  shield is usually ove rlapped withove rlap p e dpor t io n s b ei n g s o l dered together.  Typically ,t he  shields a r e c or rugated  transv ersel y  of the  longitud inal axis  o f th e cab le to faci litate b ending of the c a bl e.
It  ha s been  d ete rmine d that aneffec tive m et hod fo r imp ro ving the  buckling performance o f Stal pethcab le is toinc r eas e the cro ss-s ectional s tif fne ss by  ti g hteni ng t h ecab l e cro ss-s e ction. Of co urs e ,  a ny tightnes s i n t he ca ble must b e ac complished withou t  overly compre ssin g the  co r e, w hi ch could affec t t he e lectrica lperformance  of theca b le. A lso, c hanges  to jac k e tt hickne ss,tofloodingcom po u nds, an dto jacket ingma terial s have been i nvestigated, but  none o f the s e h as si gn ificant l y im proved the  performanc e.
Inaddi tionto shea th  buckl ing ,another ar e a of conc ern i s the d if fusi onof wat er v a p or th roug hthe  plasticj a ck e twh i chmayresul tin a n undesir a bly high  mo i sture l ev eli n side t h es h eath on acab le. S e e  for examp l e E. D. Metca lf "ABonded  Non-Co r rug at ed Alum inu m - Polyethyl ene Sheat h ing  S yste m For Te le phon eCab le " pp. 235
 2005-122150._In recent_years, several factors have_necessitated that_relatively_large pair_size_communications cable cores_be protected with_a cover that exhibits_an improved mechanical_performance._The cover which is commonly referred to as a sheath system generally includes layers_of_metal and_plastic_which_are disposed concentrically about the_core. Relatively large pair size_cores, e.g.,_3600 pairs, have increased in popularity, but their_size_has resulted in_cable sheath buckling and/or rupture, particularly in cold weather_installations and in the use of_high production placing_equipment.
Sheath_buckling_is characterized by distortions,_such as ripples, for example, in_the sheath that occur when the_cable is bent or twisted. These ripples_can snag other materials which the_cable engages or can become_abraded during_installation. In some instances, the_sheath ruptures and_hence no_longer protects the_core.
These cables usually include a multi-conductor_core, an inner_metallic tube which is called a_shield_and which provides_protection_against_external electrical_interference, an outer_metallic_shield and_a_plastic jacket. Cables of this construction_are_well known in the industry and have_been referred to as_Stalpeth_cables. See U.S. Pat._No. 2,589,700 which issued on_Mar. 18, 1952, in the name_of H._G. Johnstone._Each of the shields is usually formed by wrapping a metallic_strip about the core to form_a longitudinally extending seam._The seam_for_the outermost shield_is_usually overlapped_with overlapped portions being soldered together. Typically,_the shields_are corrugated transversely of the longitudinal_axis of the cable_to_facilitate bending of the cable.
It has_been determined that an effective method_for improving the buckling performance_of_Stalpeth_cable is to increase the_cross-sectional stiffness by tightening the cable_cross-section. Of course,_any tightness in the cable must be_accomplished_without overly compressing the core, which_could_affect the electrical performance of the_cable._Also,_changes to jacket thickness, to_flooding compounds, and to jacketing materials_have been investigated, but none of these has significantly_improved the performance.
In_addition to sheath buckling, another_area_of_concern is the diffusion of water vapor through the plastic_jacket which_may result in_an undesirably high moisture level inside the sheath on a_cable. See for example E. D. Metcalf_"A Bonded Non-Corrugated Aluminum-Polyethylene Sheathing System For Telephone Cable" pp. 235