To provide a constitution capable of strengthening swallowing of rainwater, and capable of reducing the dropping quantity of an object wheel, in a grating cover formed in a constitution having risk of causing the object wheel largely drop in an opening part forming clearance of a main bar wider than a width of the object wheel traveling on the clearance.
This grating cover has a guide member 21 having a water introducing surface 21a inclined larger than a flowing water gradient of a flowing water surface. An interval between a side bar 24 positioned on the upstream side in the flowing direction and the most upstream crossbar 16a positioned on its just downstream side, is set larger than an ordinary pitch between the respective crossbars. An inclination of this water introducing surface 21a is set smaller than an inclination of a virtual tangent F on the upper end of the side bar 24 when a virtual circle E having the same diameter as the object wheel A is supported at two points on the upper end of the side bar 24 and the upper end of the most upstream crossbar 16a.
WATANABE KENJI
MORIYA TORU
| JP2004124690A | 2004-04-22 | |||
| JPS6289388U | 1987-06-08 |
| WO2005071174A1 | 2005-08-04 |
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