| 摘要 |
PROBLEM TO BE SOLVED: To fit cloth in a state where appearance is not deteriorated even if the back of a backrest board is largely exposed to outside. SOLUTION: Cloth 15 is formed in a bag shape so that it completely laps the backrest board 12, and a sealing means such as a fastener 37 is arranged at an opening edge. Holes 15a and 15b from which projections 21 and 27 projectingly provided on the rear side of the backrest board 12 are exposed are disposed in cloth 15. |
