| 摘要 |
PROBLEM TO BE SOLVED: To provide a grating which makes irregularities for non-slip sufficiently formed by enlarging an area of an upper surface of a bearing bar, which hardly causes the intrusion of dust, pebbles, etc. into a section between the bearing bars, which hardly causes clogging by making the dust, the pebbles, etc. flow out, even on the occurrence of the intrusion of them, and which hardly causes distortion in manufacture by enhancing the rigidity of the bearing bar and making a barycentric position correspond to the vertical center of the bearing bar. SOLUTION: An upper end 11a and a lower side part 11b are formed in such a shape that the thickness t<SB>1</SB>of the upper end 11a and the thickness t<SB>2</SB>of the lower side part 11b are set great and satisfy the inequality: t<SB>1</SB>>t<SB>2</SB>. The upper surface is formed in an irregular shape with serrations. COPYRIGHT: (C)2006,JPO&NCIPI
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