| 摘要 |
PROBLEM TO BE SOLVED: To provide a manhole cover preventing noises caused by sounding of the manhole cover generating on running of vehicles and also preventing the cover from firmly sticking to the closely adhered face of the cover and the support frame so as not to be opened. SOLUTION: A protection material 3 is provided at the inner peripheral face 2c of the outer peripheral face 1b of the manhole cover body 1a having the peripheral face 1b formed on the tapered slant face forming a small diameter gradually from the upper end of a flange to the lower end or the inner peripheral face 2c of the support frame 2. Hence, the protection material 3 functions as a buffer material interposed between the outer peripheral face 1b of the flange of the manhole cover body 1a and the support frame 2 and also it functions as a separator to prevent the outer peripheral face 1b and the support frame 2 from sticking together due to their rust. COPYRIGHT: (C)2005,JPO&NCIPI
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