Chair seat or the like hinge

Claim 1

IN A HINGE CONSTRUCTION FOR ROCKABLY MOUNTING A CHAIR SEAT ELEMENT OR THE LIKE ON A RELATIVELY FIXED FRAME ELEMENT, A BODY STRUCTURE COMPRISING A PINTLE HAVING RESPECTIVE PORTIONS OF RELATIVELY LARGE AND RELATIVELY SMALL DIAMETERS, AND A PART HAVING A CURVED SURFACE SPACED RADIALLY FROM AND FACING INWARDLY TOWARD SAID PINTLE; A GENERALLY SPHERICAL BEARING INSERT COMPRISING MATING INSERT SECTIONS WHICH ARE CONJOINTLY FORMED TO PROVIDE AN INTERNAL BORE HAVING RESPECTIVE PORTIONS OF RELATIVELY LARGE AND RELATIVELY SMALL DIAMETERS INTERFITTING WITH THE RELATIVELY LARGE AND SMALL DIAMETER PORTIONS OF SAID PINTLE FOR MOUNTING SAID INSERT SECTIONS ON SAID PINTLE WITH SAID INSERTING BEING SPACED RADIALLY INWARDLY FROM SAID INWARDLY FACING SURFACE OF SAID BODY STRUCTURE PART AND FOR PREVENTING MOVEMENT OF SAID SPHERICAL BEARING INSERT AXIALLY OF SAID PINTLE, SAID INSERT SECTIONS BEING JOINED SUBSTANTIALLY IN A PLANE PARALLEL TO AND CONTAINING THE AXIS OF SAID PINTLE WHEREBY SAID INSERT SECTIONS, DIVIDED AT THE INSERT JOINT, MAY BE ASSEMBLED TOGETHER TO SURROUND SAID PINTLE BY PLACING ONE OF SAID INSERT SECTIONS ON SAID PINTLE AND MOVING THE OTHER OF SAID INSERT SECTIONS LATERALLY TOWARD SAID PINTLE AND SAID ONE OF SAID INSERT SECTIONS IN A DIRECTION NORMAL TO THE PINTLE AXIS; A FIRST OUTER BEARING MEMBER HAVING A GENERALLY HEMISPHERICAL INNER SURFACE CONFORMING TO SAID SPHERICAL BEARING INSERT AND AN OUTER SURFACE CURVED SIMILARLY TO SAID INAWARDLY FACING CURVED SURFACE OF SAID BODY STRUCTURE PART, THE RADIAL DIMENSIONS OF SAID FIRST OUTER BEARING MEMBER BEING SO RELATED TO THE SPACE BETWEEN SAID BEARING INSERT WHEN ON