Improved double-layer manhole cover

• Main Author: LIN QIANGQIANG
• Format: Patent
• Language: English
• Published: 22.07.2015
• Subjects: EMBANKMENTS; EXCAVATIONS; FIXED CONSTRUCTIONS; FOUNDATIONS; HYDRAULIC ENGINEERING; SOIL SHIFTING; UNDERGROUND OR UNDERWATER STRUCTURES

The utility model discloses an improved double-layer manhole cover which comprises an outer ring, a first cover and a second cover. The first cover and the second cover are movably arranged in the outer ring, the first cover is positioned above the second cover, limiting lugs are convexly arranged on the inner side wall of the outer ring and are positioned on the upper side of the second cover, penetrating notches are concavely arranged at the outer edge of the second cover, and the limiting lugs can penetrate the penetrating notches. The improved double-layer manhole cover has the advantages that the penetrating notches and the limiting lugs need to be aligned with one another at first when the second cover is about to be mounted, then the second cover can be arranged on a second convex ring and then can rotate, accordingly, the limiting lugs are staggered from the penetrating notches and are positioned at the outer edge of the second cover, limiting effects can be realized for the second cover, the second cover and the outer ring are high in close fit degree, the second cover can be prevented from being washed away by underground sewage, and problems that underground sewage gushes out of the ground, surrounding environments are affected and certain potential safety hazards exist due to the fact that the traditional second cover is easy to wash away by the underground sewage can be solved.