Patent attributes
A chair has a seat 1 and a backrest 2 and the backrest 2 is allowed to be tilted backward by elastic deformation of right and left back frame devices 4. The right and left back frame devices 4 each are composed of two unit frames 43 and 44. The back frame device 4 has a main portion 4a which are disposed outside the right and left sides of the seat 1, upper inward portions 43a and 44a which are connected to an upper rear end of the main portion 4a, lower inward portions 43b and 44b which go under the seat 1 from a lower end portion of the main portion 4a, and forward end portions 43c and 44c which are integrally connected to the lower inward portions 43b and 44b. The forward end portions 43c and 44c are fixed to the base 7. The back frame device 4 can be largely elastically deformed with the combination of a characteristic in which the back frame device is long, a characteristic in which the back frame device has the lower inward portions 43b and 44b, and a characteristic in which the back frame device has the forward end portions 43c and 44c. Accordingly, the backrest 2 can be tilted backward at a large angle.
