Patent ID: 6193315
Filing Date: 2001-02-27
Classification: A47C

Abstract:
A backrest and a chair, wherein the chair comprises a seat, a support for the seat and the backrest above the seat, the seat having a rear side; the backrest is adjustable both as to its height and its angle of tilt with respect to the seat of the chair and is detachable from the seat, the backrest comprising:a main base body including a seat part which is attachable to the seat of the chair and an upstanding part at the rear side of the seat;a main backrest including upstanding arms spaced a distance apart, and a backrest part supported on the arms;an arm holder comprised of a support which is held at the upstanding part of the main base body of the backrest and is comprised of an axis extending horizontally and oriented for enabling the backrest to pivot toward and away from the seat around the axis; the arm holder including an arm sliding part which slidably engages the arms of the backrest;an arm holding plate positionable at the side of the arms away from the arm holding member and including side flanges slidingly contacting the arms of the backrest; an opening through the arm holding plate;an arm fixing screw which extends through the arm holder and through the opening in the arm holding plate, an arm fixing nut screwed on to the arm fixing screw from the outside the arm holding plate for securing the arm holding plate against the arms of the backrest, whereby when the arm fixing nut is loosened, the arm of the backrest may be moved to raise and lower the backrest, and when the arm fixing nut is tightened on the arm fixing screw, the backrest is set in height;a front and back motion adjusting screw, the arm holder having a threaded opening therein for receiving the front and back motion adjusting screw so that the extent to which the adjusting screw may project from the arm holder toward the seat is adjustable;a contact part on the adjusting screw and the adjusting screw and its contact part being positioned for engaging the upstanding part of the main base body at the contact part, such that the rotation of the adjusting screw with respect to the arm holder adjusts the tilting of the arm holder with respect to the seat and thereby adjusts the tilt of the backrest with respect to the seat by pivoting the arm holder and the backrest around the axis of the arm holder.