Self-closing door hinge

Claim 1

IN A SELF-CLOSING DOOR HINGE, THE COMBINATION COMPRISING, A PAIR OF HINGE LEAVES HAVING INTERFITTING KNUCKLES PROVIDING A COMMON PIVOTAL OPENING, A PINTLE RECEIVED IN SAID PIVOTED OPENING AND HOLDING SAID HINGE LEAVES IN RELATIVE SWINGING RELATION, A FIRST CYLINDRICAL CAM MEMBER SECURED TO ONE OF SAID HINGE LEAVES AND SURROUNDING SAID PINTLE AND HAVING AT ONE END A FLAT CAM SURFACE INCLINED TO THE LONGITUDINAL AXIS OF SAID PINTLE, A SECOND CYLINDRICAL CAM MEMBER SLIDABLE ARRANGED ON SAID PINTLE AND HAVING GUIDE MEANS CONSTRAINING SAID SECOND CAM MEMBER TO MOVEMENT ALONG AN EDGE PORTION OF THE OTHER OF SAID HINGE LEAVES IN THE DIRECTION OF SAID LONGITUDINAL AXIS, SAID SECOND CYLINDRICAL CAM MEMBER HAVING AT ONE END A FLAT CAM SURFACE FACE-TO-FACE IN ABUTMENT WITH SAID CAM SURFACE OF SAID FIRST CAM MEMBER WHEN SAID HINGE LEAVES ARE IN SUBSTANTIALLY FULLY OPEN POSITION, MEANS FOR RESILIENTLY CONSTRAINING SAID SECOND CAM MEMBER INTO ABUTTING RELATION WITH SAID FIRST CAM MEMBER FOR URGING SAID HINGE LEAVES IN SUBSTANTIALLY FULLY OPEN POSITION, A TORSION SPRING CIRCUMJACENT SAID PINTLE AND HAVING END PORTIONS HOOKINGLY ENGAGED OVER OPPOSED MARGINAL EDGE PORTIONS OF SAID HINGE LEAVES, SAID TORSION SPRING BEING SO ARRANGED AND STRESSED TO NORMALLY URGE SAID HINGE LEAVES IN RELATIVELY CLOSED POSITION IN OPPOSITION TO THE URGING OF SAID SECOND CAM MEMBER CONSTRAINING MEANS, SAID SECOND CAM MEMBER CONSTRAINING MEANS COMPRISING A HELICAL COMPRESSION SPRING CIRCUMJACENT SAID PINTLE, ONE END OF SAID COMPRESSION SPRING BEING SECURED AGAINST AXIAL MOVEMENT IN THE OUTWARD DIRECTION WITH RESPECT TO SAID PINTLE, AND THE OTHER END OF SAID COMPRESSION SPRING BEING IN ABUTMENT AGAINST THE OTHER END OF SAID SECOND CAM MEMBER.