| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a new manhole capable of improving rattling of a manhole cover and operability in cover opening work, and manufacturing at low cost without using a new mold or largely altering a conventional manufacturing process. <P>SOLUTION: A manhole includes a disc-shaped manhole cover 3 and a receiving frame 2 with a cylindrical part 2b supporting the manhole 3 on an inner peripheral surface. On an outer peripheral surface of the manhole cover 3, a tapered surface 3e with a diameter gradually decreased from an upper surface side to a rear surface side is formed, while on the inner peripheral surface of the cylindrical part 2b, another tapered surface 2g with a diameter gradually decreased from an upper end side of the cylindrical part 2b to a lower end side is formed corresponding to the tapered surface 3e. A resin layer 5 made of fluorocarbon resin is formed on at least any part of where the tapered surface 3e and the other tapered surface 2g are joined. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
