| 摘要 |
PROBLEM TO BE SOLVED: To improve the outside appearance of a backrest frame by forming the backrest frame like a plate continued from a backrest panel, and to enhance the flexural rigidity of the backrest frame. SOLUTION: Left and right side frames 20a and a lower frame 20b at the lower end of the backrest frame 20 are formed like plates, and outward U-shaped recess grooves 22 as seen from the top to be opened outward and downward U-shaped recess groove 24 as seen from a side to be opened downward are formed in both side frames 20a and 20a and the lower frame 20b respectively. The opposite faces of the recess grooves 22 and 24 are connected to each other with a plurality of flat plate-like ribs 22 and 25 facing in the front/rear directions. COPYRIGHT: (C)2007,JPO&INPIT
|
