Abstract: A hinge joint which can be installed, for example, between the body supporting portion and the back rest of the seat in a motor vehicle has a first leaf affixed to the body supporting portion, a second leaf affixed to the back rest and a horizontal pintle which pivotally connects the second leaf to the first leaf. The actuating mechanism for pivoting the second leaf comprises a pair of wedge-like sections which are biased apart to bear against the balls and/or needles of one or more antifriction bearings between the first leaf and the sections. The sections flank a motion transmitting member which is moved about the axis of the pintle in order to release the second leaf for angular movement relative to the first leaf. A centering element can be installed next to the sections between the first leaf and a sleeve of the second leaf, and the bearing or bearings can extend between such centering element and the first leaf.