Double-lid waterproof device for manhole

Abstract

Abstract PURPOSE: To prevent the invasion of water, earth and sand without fail and eliminate the play of an iron lid, by securing a waterproof film to an installed manhole frame with a packing rubber and an annular rubber. CONSTITUTION: The packing rubber 4 is fitted to the edge of the installed manhole frame 3. The waterproof film 2 is coated over the packing rubber. The periphery of the film 2 is tightened to the packing rubber 4 by the annular rubber 5. Then, the iron lid 1 is placed on the frame 3. A waterproof function is fulfilled and the invasion of earth and sand is prevented by the interaction of contraction of the packing rubber 4 with the tightening by the annular rubber 5 without using any waterproof rubber ring between the iron lid 1 and the frame 3. Moreover, the play of the iron lid due to the waterproof rubber ring is eliminated COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Koichi Kuratani

Bibliographic Details