201131233 六、發明說明： 【發明所屬之技術領域】 本發明是有關：將光纖收納於槽芯（slot core )，並 以護套披覆的光纖纜線及光纖取出方法，特別是用來在執 行中間跨接（Mid-Span )時，不會傷及槽溝內的光纖，且 容易執行光纖之切入（Cut in )作業的技術。 【先前技術】 光纖纜線，一般是由具有「將光纖收納於內部」之槽 溝的槽芯、及披覆於該槽芯周圍的護套所構成（請參考專 利文獻1 )。 當執行「在纜線的途中，撕開護套並取出經收納於槽 溝內之光纖」的作業，也就是指中間跨接作業（Mid-Span Access )時，是利用刀子之類的切開工具，在「護套之特 定領域兩端的2個位置」中的一個位置，沿著纜線的外周 方向切出缺口後，沿著纜線長度方向使刀子進入護套，再 藉由於另一個位置沿著纜線的外周方向切出缺口，進而切 開該護套。在此之後，取下護套，從槽芯的槽溝將光纖朝 外部取出。 〔專利文獻1〕日本實開平6 - 50009號公報 【發明內容】 〔發明欲解決之課題〕 前述護套的撕開作業，由於是利用刀子切開護套，因 -5- 201131233 此必須仔細注意，以避免刀子進入槽芯的開口部，而傷及 收納於槽溝內的光纖。 有鑑於此，本發明的目的是提供一種：中間跨接時不 會傷及槽溝內的光纖，且任何人都能簡單地執行光纖之切 入作業的光纖纜線、及光纖取出方法。 〔解決課題之手段〕 本發明的第1態樣爲光纖纜線，其要旨在於：具備光 纖；和具有「收納並保持前述光纖之槽溝」的槽芯；及「 包含前述槽溝的開口部，而披覆槽芯整體」的護套，前述 護套是形成：具有以相同的中心點作爲中心之外徑與內徑 的表層，前述護套包含：與前述槽芯的前述開口部相對向 的第1護套部位；及作爲前述第1護套部位以外之部位所形 成的第2護套部位，前述第1護套部位是較前述第2護套部 位更厚。 前述第1護套部位，亦可較前述第2護套部位更朝向外 側，而突出於徑方向。 前述第1護套部位，亦可具有前述開口部之寬度以上 的寬度。 前述第1護套部位，亦可從前述開口部朝向前述槽溝 內而突出。 前述第1護套部位，亦可具有與前述開口部的寬度相 等的寬度。 前述第2護套部位，亦可具有：被設在前述光纖纜線 ⑧ -6- 201131233 的長度方向上，且用來表示「將前述光纖從前述槽 部取出用」之切入位置的標誌。 本發明的第2態樣，是從下述的光纖纜線取出 方法，該光纖纜線具有：光纖；和具有「將前述光 於其中的溝槽」的槽芯；及「包含前述槽溝的開口 披覆槽芯整體」的護套，前述護套是形成：具有以 中心點作爲中心之外徑與內徑的表層，前述護套包 前述槽芯的前述開口部相對向的第1護套部位；及 述第1護套部位以外之部位所形成的第2護套部位， 1護套部位是較前述第2護套部位更厚，其要旨在於 述第2護套部位’使切開工具的切刃進入至「到達_ 護套部位之內表面」的位置爲止，並在維持著該切 置的狀態下，沿著光纖纜線的外周方向切出缺口。 〔發明的效果〕 在本發明的光纖纜線中’由於護套是形成「具 同的中心點作爲中心之外徑與內徑」的表層，因此 遍及全周地形成一致的護套厚度。接著，在本發明 纜線中’由於「與槽芯的開口部相對向」的第1護 是較第2護套部位更厚，因此在中間跨接作業時， 刀子等切開工具的切刃，進入至到達「與前述開口 向之護套部位以外」的護套部位的內表面爲止，並 的外周方向切出缺口，由於在第1護套部位處切刃 達護套的內表面’因此切刃進入槽芯的開口部且不 溝朝外 光纖的 纖收納 部，而 相同的 含：與 作爲前 前述第 :在前 &述第2 刃之位 有以相 可大致 的光纖 套部位 只要使 部相對 在纜線 不會到 會傷及 201131233 光纖，可執行光纖的切入作業。 根據本發明的光纖取出方法，只要在對應於「取出光 纖之部位」的第2護套部位，使切開工具的切刃進入至「 到達其內表面」的位置爲止，並在維持著該切刃位置的狀 態下，沿著纜線的外周方向切出缺口，由於在第1護套部 位處切刃不會到達護套的內表面，因此切刃進入槽芯的開 口部不會傷及光纖，任何人都能簡單地執行光纖的切入作 業。 【實施方式】 以下，參考圖面，詳細地說明採用本發明的具體實施 形態。 「第1實施形態」 第1圖是顯示第1實施形態的光纖纜線，其中（A )爲 該光纖纜線的剖面圖，（B)是從設有「用來表示切入該 光纖纜線之位置」的標誌的那一側（第1圖（A )的箭號A 方向）觀視光纖纜線的圖，第2圖是顯示第1實施形態之光 纖纜線的中間跨接作業，其中（A )是顯示利用刀子對護 套施以環形切割之態樣的程序圖，（B )是顯示沿著標誌 以刀子將護套朝纜線長度方向切開之態樣的程序圖。 第1實施形態的光纖纜線1，如第1圖（A )所示，是由 以下所形成：將光纖2收納於槽溝3內並加以保持的槽芯4 ;及包含該槽溝3的開口部5，而將槽芯4整體予以披覆的 -8 - ⑧ 201131233 護套6。 光纖2可採用：光纖素線、光纖芯線、光纖帶芯線等 。光纖素線是指：在光纖上披覆著紫外線硬化樹脂的線材 。光纖芯線是指：在光纖上披覆塑膠樹脂，使其直徑較光 纖素線更大的線材。光纖帶芯線是指：平行地排列數條光 纖素線，並以紫外線硬化樹脂加以披覆的線材。在第1圖 (A)中，是採用光纖帶芯線，並將複數條該光纖帶芯線 (1 〇條）收納於槽溝3內。光纖2與槽溝3之間，可以夾介 著干涉材、或亦可具有空隙。 槽芯4，是將光纖2收納於內部並加以保持的保持構件 ’且具有「在從光纖纜線1的中心點C處偏移的位置，具有 中心點而形成圓弧」的槽溝3。該槽芯4是由壓出成形所， 在其長度方向上形成「垂直剖面呈現C形剖面的形狀」。 該槽芯4的厚度並不一致，是從形成有開口部5的部位，朝 向「與該開口部5相反側」的部位緩緩地增加。相反地說 ，槽芯4的厚度，是從與槽溝3底部對應的部位，朝形成有 開口部5的部位緩緩地減少。 此外’爲了抑制「因爲在鋪設有光纖纜線1的場所所 承受的熱之類的影響」，以致護套6形成熱收縮而使該光 纖纜線本身產生變形的情形，乃在槽芯4埋入有2個抗張力 體7。抗張力體7，譬如是由鋼線或F R P等的線材所形成。 護套6被形成爲：具有以相同的中心點（光纖纜線1的 中心點C )作爲中心的外徑與內徑的表層。該護套6是藉由 壓出成形所形成’該壓出成形是形成：以聚乙烯樹脂披覆 -9 * 201131233 「收納著光纖2的槽芯4」的整個周圍。在成形時，添加「 用來避免聚乙烯樹脂進入槽溝3內」包覆帶（圖示省略） 以封住前述開口部5。 如上述所形成的護套6，除了與「前述槽芯4的前述開 口部5」相對向的部位以外，所有部位的厚度均大致形成 —致。一致的厚度，當然是指相同尺寸的厚度，其中也包 含所謂「製造上的尺寸誤差」。但是，在本實施形態中， 與「前述槽芯4的前述開口部5」相對向的護套部位（第1 護套部位）6A，是較去除該部位以外的其他護套部位（第 2護套部位）6B更厚。 換一個方式說明，護套6之中，只有與「槽芯4的開口 部5」相對向的護套部位6A，突起成較「具有大致一致厚 度的其他護套部位6B」更厚的凸條。換言之，與該槽芯4 的開口部5相對向的護套部位6 A，相對於其他的護套部位 6B，是朝向纜線外側突出於徑方向而使其厚度變厚、且沿 著纜線長度方向而形成。 護套部位6A，具有較「前述槽芯4的前述開口部5」的 寬度W1更寬的寬度W2。因此，與槽芯4的開口部5相對向 的護套部位6 A，形成覆蓋該開口部5的前方。護套部位6 A ，雖然至少較「未與開口部5相對向的護套部位6B」更厚 即可，但倘若太厚將導致纘線外徑變大’故其上限値（指 厚度的上限）是由纜線外徑所決定。 此外，在前述護套6的外表面6 a設有標誌8 ’該標誌8 是用來表示「當利用刀子在護套6的長度方向上切出缺口 ⑧ -10- 201131233 ，將光纖2從槽溝3朝外部取出時」的切入位置。前述標誌 8被設在：與前述槽芯4的開口部5相對向之護套部位6A以 外的部位。在第1圖中，標誌8是設在前述開口部5之相反 側的護套部位6 B。該標誌8被設成「沿著光纖纜線1的長度 方向形成直線」的線，且形成：譬如能以不同於護套6的 顏色來加以辨識。 在如上述方式所構成的光纖纜線1中，當執行「在纜 線的途中撕開護套6，而取出已收納於槽溝3內的光纖2」 的作業，也就是指中間跨接作業（光纖取出作業），則如 第2圖（A)所示，是利用切開工具，也就是指刀子9，在 護套6之特定領域兩端的2處位置中的一處位置，沿著纜線 的外周方向切出缺口。刀子9之切刃最初切入的位置，是 設有標誌8的位置。此外，刀子9的切入深度，是從護套6 的外表面6a到達內表面6b的位置（到達槽芯4的位置）。 當「將刀子9設定於該切入深度位置，並在維持該位置的 狀態下’使刀子9繞著纜線周方向迴旋時」之刀子前端的 切入軌跡1 〇，是以第2圖（A )中的虛線表示。而切口 1丨的 切入深度’能以切開工具來調整維持其切刃深度。 與前述槽芯4的開口部5相對向的護套部位6A，由於較 其他的護套部位6B更厚，因此刀子9的切刃無法到達內表 面6b。換言之’護套部位6A，不會被刀子9所貫穿而成爲 連接於護套6的狀態。除此之外的護套部位6B，則是藉由 刀子9而被施以環形切割。藉此，護套6的大部分領域是經 刀子9施以環形切割’而使連接的部位變少。換個角度來 -11 - 201131233 看，除了護套部位6A之外的其他護套部位6B ’是全部被切 離。 接下來，使刀子9沿著前述標誌8進入纜線長度方向’ 而切開護套6(縱向切開）。此時，刀子9的切刃切入直到 抵達前述槽芯4的位置爲止。一旦執行了上述的動作’便 將如第2圖（B )所示，在護套6形成切口 1 1 »接著’沿著 標誌8使刀子9的切刃進入「切入纜線長度方向的終點位置 j ，也就是指另一個位置，再以相同的方式沿著纜線的外 周方向切出缺口。接著，將手放在該切口 11並撕開「經環 形切割之部位」的護套6後，從槽芯4的槽溝3將光纖2朝外 側取出。 根據該第1實施形態的光纖纜線1，由於與槽芯4的開 口部5相對向的護套部位6A較其他的部位6B更厚’因此當 中間跨接作業時，只要使刀子9等切開工具的切刃進入至 :到達「與前述開口部5相對向的護套部位6 A以外」之護 套部位6B的內表面6b的位置爲止，並在纜線的外周方向切 出缺口，由於在護套部位6A處切刃無法到達護套6的內表 面6b，故切刃進入槽芯4的開口部5也不會傷及光纖2’光 纖2的切入作業可容易地執行。 此外，根據第1實施形態的光纖纜線1，由於護套部位 6A具有前述開口部5之寬度W1以上的寬度W2 ’故可防止刀 子9貫穿護套6後從開口部5進入槽溝3內。因此’在利用刀 子9對護套6實施環形切割的場合中，可更進一步避免已收 納於前述槽溝3內的光纖2被刀子9所傷及。 ⑧ -12- 201131233 此外，根據第1實施形態的光纖纜線1，由於 4的開口部5相對向之護套部位6A以外的部位6B， 示「縱向撕開護套6時，刀子9的切入位置」的| 纜線長度方向上，故可將該標誌8作爲導引’只調 沿著該標誌8切入，便可簡單地將護套6縱向撕裂 此外，根據第1實施形態的光纖纜線1 ’護Ϊ 分領域是在僅有護套部位6A連接的狀態下，由7 環形切割。換言之，連接「經環形切割之部位」 少。因此，切開護套6的作業變得容易，可更簡 將光纖2從槽溝3取出的作業。 「第2實施形態」 第3圖是顯示第2實施形態之光纖纜線的剖Ϊ 圖是顯示第2實施形態之光纖纜線的中間跨接作 (A )是顯示以刀子對護套實施環形切割之態樣 ，（B )則是顯示以刀子沿著標誌’將護套朝纜 向切開之態樣的程序圖。 在第2實施形態中，僅針對與第1圖及第2圖戶 實施形態的光纖纜線1不同的部分做說明，並對 分標示相同的圖號，並省略該部分的說明。 第2實施形態的光纖纜線1也與第1實施形態 槽芯4的開口部5相對向的護套部位（第1護套部 是較其他的護套部位（第2護套部位）6B更厚。 套部位6A是從該開口部5朝前述槽溝3內突出。 在與槽芯 將用來表 I誌8設在 ΐ使刀子9 〇 g 6的大部 ]子9施以 的部位變 單地執行 3圖，第4 業，其中 的程序圖 線長度方 斤示之第1 相同的部 相同，與 位）6Α， 但是，護 護套部位 -13- 201131233 6A的厚度，是與第1實施形態中所形成之護套部位6A的厚 度相同的程度。雖然在第1實施形態中，護套部位6A是朝 向光纖纜線1的外側而突出於徑方向，但在第2實施形態中 則與其相反，是朝向光纖纜線1的內側（亦即，朝向纜線 中心C )而突出於徑方向。 護套部位6A，具有與前述槽芯4之開口部5的寬度W1 同等的寬度W3。所謂同等的寬度是指：除了與開口部5相 同的尺寸之外，也包含較開口部5的寬度W1略爲狹小的寬 度。在本實施形態中，護套部位6A最好是具有：可被前述 開口部5所嵌合之程度的寬度。 在第2實施形態的光纖纜線1中，當執行中間跨接作業 時，如第4圖（A)所示，是利用切開工具，也就是指刀子 9，在護套6之特定領域兩端的2個位置中的一個位置，沿 著纜線的外周方向切出缺口。刀子9之切刃最初切入的位 置，是設定爲：設在「前述槽芯4的開口部5之相反側」的 標誌8的位置。此外，刀子9的切入深度，是設成：從護套 6的外表面6a到達內表面6b的位置。使刀子9到達該切入深 度位置，並在維持著該位置的狀態下，使刀子9繞著纜線 周方向迴旋時，刀子前端的切入軌跡10，是以第4圖（A) 中的虛線來表示。 與前述槽芯4的開口部5相對向的護套部位6A，由於較 其他的護套部位6B更厚，因此刀子9的切刃不會到達內表 面6b。因此，在護套部位6A處，刀子9不會貫穿而形成連 接狀態。除該部分以外的護套部位6B，則由刀子9施以環 ⑧ -14- 201131233 形切割。藉此，在護套6的大部分領域中’是經刀子9施以 環形切割，而使連接的部位變少。換個角度來看’除了護 套部位6 A之外的其他護套部位6 B，是全部被切離。 接下來，沿著前述標誌8使刀子9的切刃進入纜線長度 方向，並切開護套6而形成縱向切開。此時’由於在護套6 設有標誌8，因此可藉由使刀子9沿著該標誌8移動’而筆 直地將護套6予以縱向切開。藉此’如第4圖（B)所示’ 在護套6形成切口 11。接著’沿著標誌8’使刀子9的切刃 進入「切入纜線長度方向的終點位置」’也就是指另一個 位置，再以相同的方式沿著纜線的外周方向切出缺口。接 著，將手放在該切口 1 1並撕開「經環形切割之部位」的護 套6後，從槽芯4的槽溝3將光纖2朝外側取出。 根據第2實施形態的光纖纜線1，與第1實施形態相同 ，刀子9的切刃進入槽芯4的開口部5也不會傷及光纖2，能 容易地執行光纖2的切入作業。 此外，根據第2實施形態的光纖纜線1，由於使護套部 位6A從槽芯4的開口部5朝槽溝3內突出，因此在護套6的外 表面6a不會有突起，故無需加大纜線徑。 此外，根據第2實施形態的光纖纜線1，由於護套部位 6A具有與「前述開口部5的寬度W1」同等的寬度W3，故可 防止刀子9貫穿護套6而從開口部5進入槽溝3內。因此，在 利用刀子9對護套6實施環形切割的場合中，可更進一步避 免「已收納於前述槽溝3內的光纖2」被刀子9所傷及的情 形。 -15- 201131233 〔產業上的利用性〕 本發明可利用於下述的光纖纜線，該光纖纜線可用於 :切開護套，並取出被收納於槽芯的光纖。 【圖式簡單說明】 第1圖：是顯示第1實施形態的光纖纜線，其中（A ) 爲該光纖纜線的剖面圖，（B)是從設有「用來表示切入 該光纖纜線之位置」的標誌的那一側（第1圖（A )的箭號 A方向）觀視光纖纜線的圖。 第2圖：是顯示第1實施形態之光纖纜線的中間跨接作 業，其中（A )是顯示利用刀子對護套施以環形切割之態 樣的程序圖，（B )是顯示沿著標誌以刀子將護套朝纜線 長度方向切開之態樣的程序圖。 第3圖：是顯示第2實施形態之光纖纜線的剖面圖。 第4圖：是顯示第2實施形態之光纖纜線的中間跨接作 業，其中（A )是顯示以刀子對護套實施環形切割之態樣 的程序圖，（B )則是顯示以刀子沿著標誌，將護套朝續 線長度方向切開之態樣的程序圖。 明 說 符 件 元 要 主 C :中心點 1 :光纖纜線 2 :光纖 3 :槽溝 ⑧ -16- 201131233 4 :槽芯 5 :開口部 6 :護套 6A :護套部位 6B ’·護套部位 6a :外表面 6b :內表面 7 :抗張力體 8 :標誌 9 ·_刀子 1 0 :切入軌跡 1 1 :切口 -17-201131233 VI. Description of the Invention: [Technical Field] The present invention relates to a fiber optic cable and an optical fiber take-out method for housing an optical fiber in a slot core and sheathed, in particular for performing In the middle of the Mid-Span, the fiber in the groove is not damaged, and the technique of cutting in the fiber is easy to perform. [Prior Art] The optical fiber cable is generally composed of a groove core having a groove in which the optical fiber is housed inside, and a sheath coated around the groove core (refer to Patent Document 1). When performing the operation of "ripping the sheath and taking out the optical fiber accommodated in the groove on the way of the cable", that is, when the middle-span access is used, it is a cutting tool such as a knife. At one of the "two positions at both ends of the specific area of the sheath", the notch is cut along the outer circumferential direction of the cable, and the knife is inserted into the sheath along the length of the cable, and by another position along the edge A notch is cut in the outer circumferential direction of the cable, and the sheath is cut. After that, the sheath is removed and the fiber is taken out from the groove of the core. [Patent Document 1] Japanese Unexamined Patent Publication No. Hei No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 6-50009. [Problem to be Solved by the Invention] The tearing operation of the sheath is performed by cutting the sheath with a knife, and it is necessary to pay careful attention to it from -5 to 201131233. The knives are prevented from entering the opening of the slot core, and the optical fibers housed in the slots are damaged. In view of the above, an object of the present invention is to provide an optical fiber cable which does not damage the optical fiber in the groove during intermediate bridging, and which can easily perform the optical fiber cutting operation, and a fiber removing method. [Means for Solving the Problem] A first aspect of the present invention is an optical fiber cable, comprising: an optical fiber; and a groove core having a groove for accommodating and holding the optical fiber; and an opening including the groove a jacket that covers the entire core of the groove, the sheath is formed with a surface layer having an outer diameter and an inner diameter centered on the same center point, and the sheath includes: facing the opening of the groove core The first sheath portion; and the second sheath portion formed as a portion other than the first sheath portion, the first sheath portion is thicker than the second sheath portion. The first sheath portion may protrude outward in the radial direction from the second sheath portion. The first sheath portion may have a width equal to or larger than the width of the opening. The first sheath portion may protrude from the opening toward the groove. The first sheath portion may have a width equal to the width of the opening. The second sheath portion may have a mark that is provided in the longitudinal direction of the optical fiber cable 8 -6 - 201131233 and indicates a cutting position of "the optical fiber is taken out from the groove". According to a second aspect of the present invention, there is provided a fiber optic cable comprising: an optical fiber; and a groove core having a groove for illuminating the light; and "including the groove a sheath that covers the entire groove core, the sheath is formed with a surface layer having an outer diameter and an inner diameter centered on a center point, and the sheath includes a first sheath facing the opening of the groove core a second sheath portion formed by a portion other than the first sheath portion, wherein the sheath portion is thicker than the second sheath portion, and the second sheath portion is intended to be a cutting tool The cutting edge enters the position of "reaching the inner surface of the sheath portion", and the notch is cut along the outer circumferential direction of the optical fiber cable while maintaining the cutting. [Effects of the Invention] In the optical fiber cable of the present invention, since the sheath is a surface layer in which "the outer diameter and the inner diameter of the center point are the same as the center", a uniform sheath thickness is formed over the entire circumference. Next, in the cable of the present invention, the first guard that is "opposite the opening of the groove core" is thicker than the second sheath portion. Therefore, when the intermediate bridge is engaged, the cutter cuts the cutting edge of the tool. Entering the inner surface of the sheath portion that reaches the "outside of the sheath portion with the opening", the notch is cut in the outer circumferential direction, and the cutting edge reaches the inner surface of the sheath at the first sheath portion. The blade enters the opening of the groove core and does not groove toward the fiber accommodating portion of the outer fiber, and the same includes: a portion of the fiber ferrule that is substantially similar to the position of the first and the second blade The part of the cable will not damage the 201131233 fiber, and the fiber can be cut in. According to the optical fiber take-out method of the present invention, the cutting edge of the cutting tool is brought to the position of "reaching the inner surface" at the second sheath portion corresponding to the "part of the optical fiber taken out", and the cutting edge is maintained. In the position state, the notch is cut along the outer circumferential direction of the cable, and since the cutting edge does not reach the inner surface of the sheath at the first sheath portion, the cutting edge enters the opening of the groove core without damaging the optical fiber. Anyone can simply perform the fiber-cutting operation. [Embodiment] Hereinafter, a specific embodiment of the present invention will be described in detail with reference to the drawings. "First Embodiment" Fig. 1 is a view showing a fiber optic cable according to a first embodiment, wherein (A) is a cross-sectional view of the optical fiber cable, and (B) is provided with "for indicating the cutting of the optical fiber cable. The side of the mark of the position (the direction of the arrow A of the first figure (A)) is a view of the optical fiber cable, and the second figure shows the intermediate jumper of the optical fiber cable of the first embodiment, wherein A) is a program diagram showing a state in which a circular cut is applied to a sheath by a knife, and (B) is a program diagram showing a state in which a sheath is cut along a length of a cable with a knife along a mark. As shown in FIG. 1(A), the optical fiber cable 1 of the first embodiment is formed by a groove core 4 in which the optical fiber 2 is housed in the groove 3 and held therein, and a groove 3 including the groove 3. The opening portion 5, and the ferrule 4 is entirely covered by the -8 - 8 201131233 sheath 6. The optical fiber 2 can be: an optical fiber wire, an optical fiber core wire, an optical fiber ribbon wire, and the like. The optical fiber line refers to a wire coated with an ultraviolet curing resin on an optical fiber. The optical fiber core refers to a wire that is coated with a plastic resin on the optical fiber to make it larger in diameter than the optical fiber. The optical fiber ribbon is a wire in which a plurality of optical fiber wires are arranged in parallel and covered with an ultraviolet curing resin. In Fig. 1(A), an optical fiber ribbon is used, and a plurality of the optical fiber ribbons (one string) are housed in the groove 3. Between the optical fiber 2 and the groove 3, an interference material may be interposed or a void may be provided. The groove core 4 is a holding member ′ in which the optical fiber 2 is housed and held therein, and has a groove 3 having a center point and a circular arc at a position shifted from the center point C of the optical fiber cable 1. The groove core 4 is formed by extrusion molding, and has a shape in which a vertical cross section exhibits a C-shaped cross section in the longitudinal direction. The thickness of the groove core 4 does not match, and the portion where the opening portion 5 is formed gradually increases toward the portion "opposite the opening portion 5". On the other hand, the thickness of the groove core 4 is gradually reduced from the portion corresponding to the bottom portion of the groove 3 toward the portion where the opening portion 5 is formed. In addition, in order to suppress "the influence of heat due to the place where the optical fiber cable 1 is placed", the sheath 6 is thermally contracted to deform the optical fiber cable itself, and is buried in the core 4 There are 2 tensile strength bodies 7 in. The tensile body 7, for example, is formed of a wire such as a steel wire or F R P. The sheath 6 is formed to have a surface layer having an outer diameter and an inner diameter centered on the same center point (the center point C of the optical fiber cable 1). The sheath 6 is formed by extrusion molding. The extrusion molding is formed by coating a polyethylene resin -9 * 201131233 "the core 4 in which the optical fiber 2 is housed". At the time of molding, a cover tape (not shown) for "avoiding the polyethylene resin from entering the groove 3" is added to seal the opening portion 5. The sheath 6 formed as described above is formed substantially in the thickness of all the portions except for the portion facing the "opening portion 5 of the groove core 4". A uniform thickness, of course, refers to the thickness of the same size, which also includes the so-called "size error in manufacturing". However, in the present embodiment, the sheath portion (first sheath portion) 6A facing the "opening portion 5 of the groove core 4" is a sheath portion other than the portion to be removed (the second guard) The sleeve part) 6B is thicker. Alternatively, in the sheath 6, only the sheath portion 6A facing the "opening portion 5" of the groove core 4 is protruded into a thicker ridge than the "other sheath portion 6B having a substantially uniform thickness". . In other words, the sheath portion 6 A facing the opening portion 5 of the groove core 4 protrudes from the outer side of the cable in the radial direction with respect to the other sheath portion 6B to have a thick thickness and along the cable. Formed in the length direction. The sheath portion 6A has a width W2 that is wider than the width W1 of the "opening portion 5 of the groove core 4". Therefore, the sheath portion 6A facing the opening portion 5 of the groove core 4 is formed to cover the front side of the opening portion 5. The sheath portion 6 A may be at least thicker than the "sheath portion 6B that is not opposed to the opening portion 5", but if it is too thick, the outer diameter of the twisted wire becomes large, so the upper limit 値 (the upper limit of the thickness) ) is determined by the outer diameter of the cable. Further, the outer surface 6a of the sheath 6 is provided with a mark 8' which is used to indicate "when the gap is cut in the longitudinal direction of the sheath 6 by a knife 8-10-201131233, the optical fiber 2 is removed from the groove The cutting position when the groove 3 is taken out to the outside. The mark 8 is provided at a portion other than the sheath portion 6A facing the opening 5 of the groove core 4. In Fig. 1, the mark 8 is a sheath portion 6 B provided on the opposite side of the opening 5. The mark 8 is set to a line "forming a straight line along the length of the optical fiber cable 1" and formed such that it can be distinguished by a color different from the sheath 6. In the optical fiber cable 1 configured as described above, when the operation of "pulling the sheath 6 in the middle of the cable and taking out the optical fiber 2 accommodated in the groove 3" is performed, that is, the intermediate jumper operation is performed. (Optical fiber take-out operation), as shown in Fig. 2(A), is a cutting tool, that is, a knife 9, at one of two positions at both ends of a specific field of the sheath 6, along the cable Cut the gap in the outer circumferential direction. The position where the cutting edge of the knife 9 is initially cut is the position where the mark 8 is provided. Further, the cutting depth of the knife 9 is a position from the outer surface 6a of the sheath 6 to the inner surface 6b (a position reaching the groove core 4). When the knife 9 is set at the plunging depth position and the knives 9 are rotated around the cable in the state where the knives 9 are maintained, the trajectory 1 刀 of the front end of the knives is shown in Fig. 2 (A). The dotted line in the middle. The plunging depth of the slit 1' can be adjusted by the cutting tool to maintain the depth of the cutting edge. Since the sheath portion 6A facing the opening 5 of the groove core 4 is thicker than the other sheath portions 6B, the cutting edge of the blade 9 cannot reach the inner surface 6b. In other words, the sheath portion 6A is not connected to the blade 9 and is connected to the sheath 6. The sheath portion 6B other than this is subjected to a circular cut by the knife 9. Thereby, most of the area of the sheath 6 is such that the knife 9 is subjected to a circular cut' to reduce the number of joints. From another angle -11 - 201131233, it is seen that all the sheath portions 6B' except the sheath portion 6A are all cut away. Next, the knife 9 is caused to enter the cable length direction ' along the aforementioned mark 8 to cut the sheath 6 (longitudinal slit). At this time, the cutting edge of the knife 9 is cut until the position of the groove core 4 is reached. Once the above-described action is performed, a slit 1 1 is formed in the sheath 6 as shown in Fig. 2 (B). Then, along the mark 8, the cutting edge of the knife 9 is brought into the end position of the length of the cut cable. j, that is, another position, and then the notch is cut in the same manner along the outer circumferential direction of the cable. Then, after placing the hand on the slit 11 and tearing off the sheath 6 of the "circularly cut portion", The optical fiber 2 is taken out from the groove 3 of the slot core 4 to the outside. According to the optical fiber cable 1 of the first embodiment, the sheath portion 6A facing the opening portion 5 of the slot core 4 is thicker than the other portions 6B. Therefore, when the intermediate jumper is engaged, the knife 9 or the like is cut. The cutting edge of the tool enters the position of the inner surface 6b of the sheath portion 6B which is "other than the sheath portion 6A facing the opening portion 5", and cuts a notch in the outer circumferential direction of the cable. Since the cutting edge at the sheath portion 6A cannot reach the inner surface 6b of the sheath 6, the cutting edge entering the opening portion 5 of the groove core 4 does not damage the optical fiber 2', and the cutting operation of the optical fiber 2 can be easily performed. Further, according to the optical fiber cable 1 of the first embodiment, since the sheath portion 6A has the width W2 of the width W1 or more of the opening 5, it is possible to prevent the knife 9 from penetrating the sheath 6 and entering the groove 3 from the opening 5. . Therefore, in the case where the sheath 6 is subjected to the annular cutting by the knife 9, the optical fiber 2 received in the groove 3 can be further prevented from being damaged by the knife 9. In the optical fiber cable 1 according to the first embodiment, when the opening 5 of the fourth portion is opposed to the portion 6B other than the sheath portion 6A, "the cutting of the knife 9 is performed when the sheath 6 is longitudinally torn. The position of the cable is in the longitudinal direction of the cable, so that the marker 8 can be used as a guide to cut along the mark 8 to simply tear the sheath 6 longitudinally. Further, the optical fiber cable according to the first embodiment Line 1 'The Guardian's sub-area is cut by 7 rings in a state where only the sheath portion 6A is connected. In other words, there is less connection to the "ring cut". Therefore, the work of cutting the sheath 6 becomes easy, and the work of taking out the optical fiber 2 from the groove 3 can be simplified. Fig. 3 is a cross-sectional view showing the optical fiber cable of the second embodiment. Fig. 3 is a cross-sectional view showing the intermediate cable (A) of the optical fiber cable according to the second embodiment. In the case of cutting, (B) is a program diagram showing the aspect of cutting the sheath toward the cable along the mark 'with the knife'. In the second embodiment, only the portions different from those of the optical fiber cable 1 of the first embodiment and the second embodiment will be described, and the same reference numerals will be given to the same reference numerals, and the description of the portions will be omitted. The optical fiber cable 1 of the second embodiment also faces the sheath portion of the opening 5 of the slot core 4 of the first embodiment (the first sheath portion is more than the other sheath portion (second sheath portion) 6B). The sleeve portion 6A protrudes from the opening portion 5 toward the inside of the groove 3. In the portion where the groove core is used to apply the table 9 to the large portion 9 of the knife 9 〇g 6 Execute 3 maps, 4th industry, where the length of the program line is the same as the first part of the same, and the position is 6Α, but the thickness of the sheath part-13-201131233 6A is the first The thickness of the sheath portion 6A formed in the embodiment is the same. In the first embodiment, the sheath portion 6A protrudes in the radial direction toward the outer side of the optical fiber cable 1, but in the second embodiment, it faces the inner side of the optical fiber cable 1 (i.e., the orientation). The cable center C) protrudes in the radial direction. The sheath portion 6A has a width W3 equivalent to the width W1 of the opening 5 of the groove core 4. The equivalent width means that the width W1 of the opening portion 5 is slightly narrower than the size of the opening portion 5. In the present embodiment, the sheath portion 6A preferably has a width that can be fitted to the opening portion 5. In the optical fiber cable 1 of the second embodiment, when the intermediate jumper operation is performed, as shown in Fig. 4(A), the slitting tool, that is, the knife 9, is used at both ends of the specific region of the sheath 6. One of the two positions cuts the notch along the outer circumferential direction of the cable. The position at which the cutting edge of the blade 9 is initially cut is set to the position of the mark 8 provided on the "opposite side of the opening 5 of the groove core 4". Further, the cutting depth of the knife 9 is set to a position from the outer surface 6a of the sheath 6 to the inner surface 6b. When the knife 9 is brought to the cutting depth position and the knife 9 is rotated around the cable circumferential direction while maintaining the position, the cutting path 10 of the front end of the knife is indicated by the broken line in Fig. 4(A). Said. Since the sheath portion 6A facing the opening portion 5 of the groove core 4 is thicker than the other sheath portions 6B, the cutting edge of the blade 9 does not reach the inner surface 6b. Therefore, at the sheath portion 6A, the knife 9 does not penetrate to form a connected state. The sheath portion 6B other than this portion is cut by the knife 9 by a ring 8 - 14 - 201131233. Thereby, in most areas of the sheath 6, 'the ring is cut by the knife 9, and the number of joints is reduced. From another point of view, the other sheath portions 6 B except the sheath portion 6 A are all cut away. Next, the cutting edge of the knife 9 is brought into the cable length direction along the aforementioned mark 8, and the sheath 6 is cut to form a longitudinal slit. At this time, since the flag 8 is provided on the sheath 6, the sheath 6 can be straightly cut longitudinally by moving the knife 9 along the mark 8. Thereby, the slit 11 is formed in the sheath 6 as shown in Fig. 4(B). Then, the cutting edge of the knife 9 is brought along the mark 8' into the "end position in the longitudinal direction of the cut-in cable", that is, the other position, and the notch is cut in the same manner along the outer circumferential direction of the cable. Then, by placing the hand on the slit 1 1 and tearing off the sheath 6 of the "circularly cut portion", the optical fiber 2 is taken out from the groove 3 of the core 4 to the outside. According to the optical fiber cable 1 of the second embodiment, as in the first embodiment, the cutting edge of the blade 9 enters the opening 5 of the slot core 4 without damaging the optical fiber 2, and the cutting operation of the optical fiber 2 can be easily performed. Further, according to the optical fiber cable 1 of the second embodiment, since the sheath portion 6A protrudes from the opening portion 5 of the groove core 4 into the groove 3, there is no protrusion on the outer surface 6a of the sheath 6, so that it is not necessary Increase the cable diameter. Further, according to the optical fiber cable 1 of the second embodiment, since the sheath portion 6A has a width W3 equivalent to the "width W1 of the opening portion 5", it is possible to prevent the knife 9 from penetrating the sheath 6 and entering the groove from the opening portion 5. Inside the ditch 3. Therefore, in the case where the sheath 6 is subjected to the annular cutting by the knives 9, the case where the "optical fiber 2 accommodated in the groove 3" is damaged by the blade 9 can be further prevented. -15-201131233 [Industrial Applicability] The present invention can be applied to an optical fiber cable which can be used for cutting a sheath and taking out an optical fiber accommodated in the slot core. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a fiber optic cable of a first embodiment, wherein (A) is a sectional view of the optical fiber cable, and (B) is provided with "used to indicate that the optical fiber cable is cut into The side of the mark of the position (the arrow A direction of Fig. 1 (A)) is a view of the optical fiber cable. Fig. 2 is a view showing the intermediate jumper of the optical fiber cable of the first embodiment, wherein (A) is a program diagram showing a state in which a sheath is cut by a knife, and (B) is a display along the mark. A program diagram in which the sheath is cut toward the length of the cable with a knife. Fig. 3 is a cross-sectional view showing the optical fiber cable of the second embodiment. Fig. 4 is a view showing the intermediate jumper of the optical fiber cable of the second embodiment, wherein (A) is a program diagram showing a state in which a knife is subjected to a circular cut by a knife, and (B) is a knife edge along the display. A program diagram showing the pattern of the sheath being cut toward the length of the continuous line. The main element is C: Center point 1: Fiber optic cable 2: Fiber 3: Groove 8 -16- 201131233 4: Groove core 5: Opening 6: Sheath 6A: Sheath 6B '· Sheath 6a: outer surface 6b: inner surface 7: tensile body 8: mark 9 · _ knife 1 0 : cut into track 1 1 : cut -17-