Abstract: There is noticed a dynamic frame of the chair, which comprises a seat holder (1), to which a swivel sleeve (3) is demountably attached from one side, into which a spherical head (41) of a spherical thread swivel (4) with a threaded end piece (42) is tightly seated, to which a nut (7) is demountably attached and to which a silent block bushing (2) is demountably attached from the other side, to which an annular locking ring (6) with four locking undercuts (61) and four locking noses (62) is demountably attached from one side and a frame sleeve (5) with a sliding hole (53) and four sleeve noses (51) and four sleeve reinforcement pieces (52) is detachably fastened from the other side.