| 摘要 |
PURPOSE:To facilitate a work to branch an optical fiber to the outside of a manhole at a late date by disposing an auxiliary connection box, connected to a main connection box, in a manhole. CONSTITUTION:An optical fiber main line 4 embedded in a ground is laid in a manner to cross a position closer to the bottom of a manhole 1, a straight cylindrical main connection box is disposed on the main line 4, and is connected to an auxiliary connection box 5 through a short branch line 7 pulled out from a main connection box 2. As noted above, the branch line 7 is previously pulled out from the main connection box 2 to the interior of the manhole 1 and wired to the auxiliary connection box 5. Therefore, when external branch lines 8 and 9 are needed at a late data. only the auxiliary connection box 5 is opened without touching the main connection box 2, and a branch work can be carried out. Namely, a connector 26 is also mounted on each optical fiber core of the branch line 7 and removably connected to a connectors 22 of the external branch lines 8 and 9 through respective connector adapters 27. |
