Well tools for plugging a well flow conductor

Claim 1

A WELL TOOL FOR USE IN A WELL FLOW CONDUCTOR HAVING A PLURALITY OF LONGUTUDINALLY SPACED ANNULAR RECESSES EACH PROVIDING AN UPPER DOWNWARDLY FACING SHOULDER AND A LOWER UPWARDLY FACING SHOULDER INCLUDING: A MAIN TUBULAR MANDREL HAVING MEANS FOR SECURING A WELL DEVICE WHICH IS TO BE SUPPORTED BY THE WELL TOOL IN A WELL FLOW CONDUCTOR; LOCKING MEANS CARRIED BY SAID MAIN MANDREL AND MOVABLE RELATIVE TO SAID MAIN MANDREL BETWEEN A RETRACTED POSITION WHEREIN SAID LOCKING MEANS DOES NOT PREVENT LONGITUDINAL MOVEMENT OF THE MAIN MANDREL THROUGH THE WELL FLOW CONDUCTOR AND AN EXPANDED POSITION WHEREIN SAID LOCKING MEAND EXTENDS INTO A RECESS OF THE WELL FLOW CONDUCTOR TO PREVENT LONGITUDINAL MOVEMENT OF THE MAIN MANDREL IN THE WELL FLOW CONDUCTOR; AN INNER MANDREL MOUNTED IN SAID MAIN MANDREL FOR LIMITED LONGITUDINAL MOVEMENT RELATIVE THERETO BETWEEN AN UPPER POSITION AND A LOWER POSITION, SAID WELL TOOL BEING LOWERABLE THROUGH A WELL FLOW CONDUCTOR BY MEANS DETACHABLY SECURABLE TO SAID INNER MANDREL; COENGAGEABLE MEANS ON SAID INNER MANDREL AND SAID LOCKING MEANS FOR MOVING SAID LOCKING MEANS TO SAID EXPANDED POSITION UPON UPWARD MOVEMENT OF SAID INNER MANDREL FROM SAID LOWER POSITION TOWARD SAID UPPER POSITION, SAID MEANS ON SAID INNER MANDREL MOVING UPWARDLY WITH SAID INNER MANDREL AS SAID INNER MANDREL MOVES FROM SAID LOWER POSITION TOWARD SAID UPPER POSITION; AND MEANS ON SAID INNER MANDREL MOVABLE WITH SAID INNER MANDREL AND ENGAGEABLE WITH SAID LOCK-