초록 ▼

The manhole has a frame 1 with a flange 4 to be embedded in the road and a movable cover 2 to fit in the cylindrical wall 3 of the frame. On its inside the wall 3 has three support surfaces 9 each downwardly sloping at an angle ab9 the frame has three undercut surfaces 11 extending radially. On its

The manhole has a frame 1 with a flange 4 to be embedded in the road and a movable cover 2 to fit in the cylindrical wall 3 of the frame. On its inside the wall 3 has three support surfaces 9 each downwardly sloping at an angle ab9 the frame has three undercut surfaces 11 extending radially. On its underside the cover 2 has six surfaces 14, 15. When the cover is on the frame three surfaces 14 are parallel to the corresponding surfaces 9 and the three surfaces 15 are parallel to the corresponding surfaces 11. The surfaces 9, 11 on the frame abut the surfaces 14, 15 by which the cover is held against rocking.

대표청구항 ▼

A manhole, comprising: a frame (1; 22) embedded into a surface covering, said frame having on its periphery three first support surfaces (9; 42; 42A) with a double slope extending downwardly in a circumferential direction and downwardly in a radial direction toward a center axis (X－X) of said frame,

A manhole, comprising: a frame (1; 22) embedded into a surface covering, said frame having on its periphery three first support surfaces (9; 42; 42A) with a double slope extending downwardly in a circumferential direction and downwardly in a radial direction toward a center axis (X－X) of said frame, and, between these three surfaces, said frame having three second support surfaces (11; 43; 43); a movable cover (2; 21) insertable into said frame, said cover having six surfaces (14, 15; 31, 32, 31A, 32) complimentary to said six surfaces of said frame which engage with said six surfaces of the frame when said cover is inserted into said frame.