| 摘要 |
PROBLEM TO BE SOLVED: To provide an angle adjusting device of a backrest capable of securing excellent stability and simpleness of operation.SOLUTION: A first gear 1 has a first shaft part 11 connected to a backrest 6. A first tooth face 14 is arranged in a first side face 16 of the first shaft part 11 and a first housing part 15 with a concave shape is formed in a center of the first tooth face 14. A second gear 2 has a second shaft part 21 connected to a seat part 7. A second tooth face 24 capable of meshing with the first tooth face 14 is arranged in a second side face 27 facing the first tooth face 14 of the second shaft part 21 and a second housing part 25 with a concave shape is formed in a center of the second tooth face 24. An elastic body 3 is arranged in the first housing part 15 and the second housing part 25. An angle adjusting device 10 of a backrest 6 can fix an angle of the backrest by meshing the first tooth face 14 and the second tooth face 24 with each other and adjusting the angle of the backrest by canceling the meshing. |
