Patent ID: 7731286
Filing Date: 2010-06-08
Classification: A47C

Abstract:
1. A backrest assembly comprising: a backrest board having a top end and a bottom end; a backrest frame having a top end and a lower end; and a buffering resilient device, with the backrest board pivotally attached to the backrest frame at the top ends, with the bottom end of the backrest board and the lower end of the backrest frame connected by the buffering resilient device, wherein the buffering resilient device has: two brackets made of resilient material and secured between the backrest frame and the backrest board; a transversal adjusting rod rotatably penetrating the two brackets and having an obround-shaped shaft with first and second ends, and a driving nub formed at the first end of the obround-shaped shaft; and a rotating tube with an obround-shaped passage snugly sleeving the transversal adjusting rod between the two brackets, with the rotating tube driven by the transversal adjusting rod, with the two brackets being deformed by the obround-shaped shaft with rotation of the transversal adjusting rod to change resiliency of the two brackets.