Patent attributes
A backrest includes: a back support having a top end portion provided with a pivot shaft that has two opposite end portions; a backrest cushion having a rear wall formed with two threaded holes; a coupling cover having an open end, covering the pivot shaft, and having a back wall that is formed with two counter bores; two screw bolts extending respectively through the counter bores and engaging threadedly and respectively the threaded holes to permit abutment of the open end of the coupling cover against the rear wall of the backrest cushion; and two pivoting members, each having a pivot sleeve sleeved rotatably on a respective end portion of the pivot shaft, and a linkage extending from the pivot sleeve and coupled to a respective one of the screw bolts.
