Coiling fin for tube launched missiles

Claim 1

IN AN AERIAL MISSILE, A MISSILE BODY, A FIN COMPRISING A PAIR OF RESILIENT, FLEXIBLE SHEETS EACH HAVING A GENERALLY ARCUATE CROSS-SECTION, A LEADING EDGE, A TRAILING EDGE, A TIP EDGE AND A ROOT END, SAID SHEETS BEING ARRANGED WITH THEIR CONCAVE SIDES FACING EACH OTHER AND WITH SAID LEADING EDGES, SAID TRAILING EDGES AND SAID TIP EDGES CONTACTING AND BONDED TOGETHER, SAID ROOT ENDS AND THE CENTRAL PORTIONS OF SAID SHEETS BEING FREE AND NORMALLY BOWED APART WHEN SAID FIN IS IN AN ERECT POSITION, THEREBY PROVIDING A RIGID HOLLOW AIRFOIL OF SYMMETRICAL CROSS-SECTION, SAID FIN BECOMING FLAT AND FLEXIBLE UPON MOVEMENT OF SAID BOWED SHEETS AND ROOT ENDS TOWARD EACH OTHER AND INTO ENGAGEMENT, SAID SHEETS HAVING AT LEAST ONE PAIR OF ALIGNED NOTCHES, ONE NOTCH OF SAID PAIR EXTENDING INWARDLY FROM AND BEING POSITIONED CENTRALLY OF THE ROOT END OF EACH SHEET, A PIVOT PIN ATTACHED TO EACH SHEET AT SAID ROOT END AND CONFRONTING SAID NOTCH, MEANS MOUNTED ON SAID MISSILE BODY AND CONNECTED WITH SAID ROOT ENDS FOR SECURING SAID FIN TO SAID BODY AND FOR PERMITTING SAID FIN TO BE WRAPPED ABOUT SAID BODY WHEN SAID FIN HAS BEEN MADE FLEXIBLE BY MOVEMENT OF THE CENTRAL PORTIONS AND THE ROOT ENDS OF SAID SHEETS INTO ENGAGEMENT, SAID SECURING MEANS INCLUDING A FORWARD HINGE PLATE, AN AFT HINGE PLATE, A FORWARD HINGE PIN, AND AN AFT HINGE PIN, SAID HINGE PLATES EACH HAVING A BORE THEREIN AND BEING SECURED TO SAID MISSILE BODY IN ALIGNED, SPACED APART RELATIONSHIP, SAID HINGE PINS BEING SECURED TO SAID FIN AT THE OPPOSITE EXTREMITIES OF SAID ROOT ENDS, SAID FORWARD HINGE PIN PROJECTING BEYOND SAID LEADING EDGES AND BEING SLIDABLY AND ROTATABLY RECEIVED WITHIN SAID BORE IN SAID FORWARD HINGE PLATE, AND SAID AFT HINGE PIN PROJECTING BEYOND SAID TRAILING EDGES AND BEING SLIDABLY AND ROTATABLY RECEIVED WITHIN SAID BORE IN SAID AFT HINGE PLATE, AND MEANS ATTACHED TO SAID BODY AND ENGAGEABLE WITH SAID PIVOT PINS FOR SECURING SAID FIN IS AN ERECT POSITION, SAID LAST MENTIONED MEANS INCLUDING A LOCKING DEVICE, SAID DEVICE BEING ATTACHED TO SAID MISSILE BODY HAVING THEREIN AN ELONGATED SLOT INCLUDING AN ENLARGED CENTRAL PORTION, BOTH SAID PIVOT PINS BEING RECEIVED WITHIN SAID SLOT AND BEING POSITIONED WITHIN SAID ENLARGED CENTRAL PORTION WHEN SAID SHEETS AND SAID ROOT ENDS ARE IN ENGAGEMENT, AND BEING POSITIONED AT OPPOSITE ENDS OF SAID SLOT WHEN SAID FIN IS IN AN ERECT POSITION WITH SAID SHEETS AND SAID ROOT ENDS BOWED APART.