| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laying structure or the like of a pit lid, for compatibly reducing weight and increasing strength in a simple structure and preventing floating by buoyancy when a train passes through a pit side. <P>SOLUTION: A pit lid 1 comprises a roughly rectangular planar top plate part 3, a rib provided on a back surface side of the top plate part 3, and handle parts 5 provided on both ends in the width direction, etc. On the side of a back surface 1b of the pit lid 1, a plurality of width direction ribs 7a formed in the width direction of the pit lid 1 and longitudinal direction ribs 7b formed in the longitudinal direction of the pit lid 1 and made roughly orthogonal to the width direction ribs 7a are formed. When a part surrounded by the width direction ribs 7a and the longitudinal direction ribs 7b is turned to a space, the spaces arranged at both end parts in the width direction of the pit lid 1 are turned to spaces 11a opened to the outer side in the width direction of the pit lid 1. That is, the spaces 11a are formed so as to open only on the bottom surface side and one side face side of the pit lid 1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
