Latching devices for nuclear fuel elements

Claim 1

IN A STRUCTURE INCLUDING A CHANNEL, A LATCHING MECHANISM WHICH COMPRISES, IN COMBINATION, TUBULAR CONDUIT MEANS IN LINE WITH SAID CHANNEL AND LOCATED AT THE INLET END OF SAID CHANNEL, THE INNER WALL OF SAID CONDUIT MEANS INCLUDING, IN JUXTAPOSITION, FROM THE OUTSIDE TOWARD SAID CHANNEL, A FIRST CYLINDRICAL SURFACE OF THE SAME CROSS SECTION AS SAID CHANNEL, A GROOVE OF LARGE CROSS SECTION, A FIRST TAPERING SURFACE STARTING FROM SAID GROOVE, AN INTERMEDIATE CYLINDRICAL SURFACE STATING FROM THE SMALLER END OF SAID TAPERING SURFACE, THE CROSS SECTION OF SAID INTERMEDIATE CYLINDRICAL SURFACE BEING INTERMEDIATE BETWEEN THAT OF SAID GROOVE AND THAT OF SAID CHANNEL, AND A SECOND TAPERING PORTION STARTING FROM SAID SECOND CYLINDRICAL SURFACE AND THE NARROW END OF WHICH HAS THE SAME CROSS SECTION AS SAID CHANNEL, AND A LATCHING UNIT INCLUDING A CYLINDRICAL HOLLOW BODY DIMENSIONED TO SLIDE WITH A SMALL PLAY IN SAID FIRST CYLINDRICAL SURFACE, SAID BODY BEING PROVIDED WITH SLOTS LOCATED IN AXIAL PLANES THEREOF, LATCHING FINGERS RADIALLY MOVABLE IN SAID SLOTS SO AS TO BE ABLE TO EXPAND TO THE OUTSIDE OF SAID BODY, RESILIENT MEANS FOR URGING SAID FINGERS OUTWARDLY, A MEMBER CARRIED BY SAID BODY LONGITUDINALLY SLIDABLE WITH RESPECT THERETO BETWEEN TWO END POSITIONS, A FRONTWARD ONE AND A REARWARD ONE, SAID MEMBER BEING SHAPED TO ENGAGE, WHEN IT IS IN SAID FRONTWARD POSITION, SAID FINGERS TO LOCK THEN IN RETRACTED POSITION WITH RESPECT TO SAID BODY, AND RESILIENT FRICTION MEANS CARRIED BY SAID MEMBER AND PROJECTING FROM THE OUTER WALL OF SAID BODY TO RUB AGAINST SAID CONDUIT MEANS SO AS TO BRING SAID MEMBER IN REARWARD POSITION WHEN SAID BODY IS MOVED FORWARD AND IN FRONTWARD POSITION WHEN SAID BODY IS MOVED BACKWARD.