| 摘要 |
PURPOSE:To facilitate inside fitting of a sheet by forming a partial concave portion for inserting a core material at the bottom of a seal groove when an elastic sheet is fitted through a core materaial in a circular seal groove large at the back part thereof on the inner peripheral surface of a valve box. CONSTITUTION:A seal groove 7 large at the back part thereof includes a partial concave portion 8. In case of fitting an elastic sheet 6 in the seal groove 7, first, the sheet 6 is flexibly deformed to be fitted in the seal groove 7 outside of the concave portion 8, and a core material 9 is inserted from the concave portion 8 in such a manner as to form a gap B inthe sheet 6. After both end portions of the core material 9 are located in the concave portion 8, the sheet 6 on the concave portion 8 is fitted in the groove 7. Subsequently, after both end portions of the core material 9 are located at the concave portion 8, the sheet 6 on the concave portion 8 is fitted in the groove 7, and the core material 9 located at the concave portion 8 is pushed into the sheet 6 by a bolt 11 to be fixed, so that the sheet 6 is pressed against an opposing concave portion of the groove 7. |
