Cable towed decoy with collapsible fins
AssigneeGrumman Aerospace Corporation
InventorRobert J. Lecat
Life of this patent
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Abstract
The invention extends the operational envelope of towed bodies at high altitudes and at high dynamic pressures. It features fins with large span/chord ratios, compactly stowed along the body surface, pivotally swept back with their chord broadside to the airstream. These fins generate high drag forces and large stabilizing and damping moments, even at supersonic speeds. Sweepback angles, controlled by elastic restraints, increase as fin loads increase. This minimizes variations in cable tension, even in maneuvers. Fin drag forces can also extend telescopic body elements. Fin settings can also generate vertical or lateral forces to bias decoy position.
Claims9
A collapsible fin aerobody comprising:
- a missile-shaped body;
- a plurality of elongated fins having substantially perpendicular inner corners, each fin being pivotally mounted at an inner end thereof to the body for permitting the perpendicular corner of each fin to fold against the body when in a collapsed stored condition;
- means connected between the body and each fin for restraining a deployed fin in a swept-back position relative to the body;
- and
- a tow cable connected to a forward point of the body.
A towable aircraft decoy comprising:
- a missile-shaped body;
- a plurality of elongated fins having substantially perpendicular inner corners, each fin being pivotally mounted at an inner end thereof to the body for permitting the perpendicular corner of each fin to fold against the body when in a collapsed stored condition;
- a cable connected between the body and each fin for restraining a deployed fin in a swept-back position relative to the body;
- a tow cable connected to a forward point of the body;
- and
- means for effectively extending the length of the restraining cable forcing the fins to assume a greater swept position when a preselected drag threshold is exceeded.
A body with deployable fins comprising:
- a missile-shaped body;
- a plurality of elongated fins, folded against the body in stowed position;
- pivot means connected between the fins and the rear of the body for rotating the fins about the rear of the body upon deployment;
- means connected between the body and a free end of each fin to restrain a deployed fin in a sweepback position relative to the body;
- and
- a tow cable connected to a point of the body, generally above and forward of the center of gravity.
A towable body comprising:
- a missile-shaped body;
- a plurality of elongated fins folded against the body in a stowed position;
- pivot means connected between the fins and the rear of the body for rotating the fins about the rear of the body upon deployment;
- a tow cable connected to a point of the towed body, generally above and forward of the center of gravity;
- a mechanical restraint connected between the body and each fin, restraining a deployed fin in a swept-back position relative to the body;
- means for effectively extending the length of the mechanical restraint when a preselected fin force threshold is exceeded to reduce fin forces within desired levels.
Dependencies are inferred from the claim text.