Extender for securing a closure

An apparatus for securing a closure that opens and closes by movement relative to a fixed structure, the apparatus comprising:

• a first annular fastener having a first eye, the first annular fastener being operatively secured to a first fixing surface selected from the group consisting of the closure and the fixed structure;
• a second annular fastener having a second eye, the second annular fastener being operatively secured to a second fixing surface selected from the group consisting of the closure and the fixed structure, wherein one of (a) the first fixing surface and (b) the second fixing surface is on a surface of the fixed structure and the other of (a) the first fixing surface and (b) the second fixing surface is on a surface of the closure;
• an extender having a length and a first end and an opposing second end;
• a hook with a tip disposed at the first end of the extender and an annulus disposed adjacent the second end of the extender, the tip having an end;
• a tubular rigid sheath having an interior volume and having an enclosing end and a locking end, the tubular rigid sheath being configured to enclose a portion of the length of the extender between the hook and annulus and configured to slide relative to the extender between (1) a closed state wherein the end of the tip of the hook is disposed within the interior volume of the tubular rigid sheath adjacent the enclosing end of the rigid sheath and the annulus is disposed outside the interior volume of the tubular rigid sheath adjacent the locking end of the tubular rigid sheath and (2) an open state wherein the tip of the hook is disposed outside the interior volume of the tubular rigid sheath adjacent the enclosing end of the tubular rigid sheath and the annulus is disposed within the interior volume of the tubular rigid sheath adjacent the locking end of the tubular rigid sheath, such that when a shackle of a lock is disposed in the annulus in the closed state the tubular rigid sheath is prevented from sliding relative to the extender to the open state, wherein the hook is disposed through the first eye when the tubular rigid sheath and the extender are in the closed state;
• a shackle disposed through the second eye and the annulus when the tubular rigid sheath and the extender are in the closed state, wherein movement of the closure relative to the fixed structure is limited to a fixed amount;
• and
• a chain separate from the second annular fastener, the chain being disposed between the closure and at least one element selected from the group consisting of the tubular rigid sheath and the hook, the chain comprising a series of flexibly-connected interconnecting rings;
• wherein the extender is detachable from the closure and the fixed structure by first removing the shackle from the annulus when the tubular rigid sheath and the extender are in the closed state and second configuring the tubular rigid sheath and the extender in the open state wherein the hook is removable from the first eye.