Acoustic buoy

An acoustic buoy which can be dropped from a plane, said buoy comprising a float, a plunger and an air brake connected to the float, said plunger being provided at its top with a casing which extends the wall of the float and in which the bottom part of the float moves piston-like, said bottom part of the float being provided with a bottom bearing a plurality of studs and normally being in the locked position and pushed down inside said casing, said bottom comprising bent spring blades, each spring blade being fixed at a first end to a stud of the bottom of the float and having its second end projecting within an opening provided in the cylindrical casing at a higher level than that occupied by the first ends of the blades in a latched position;

• a spacer integral with the studs at points situated just below the fixing points of the first ends of the spring blades, said spacer acting as a stop for the spring blades when the float rises above its locked position in the casing;
• a blocking device which when it is active prevents any pushing of the float into the casing, said spring blades in the locked position being extended and tending to push the float down into the casing, means for rendering said blocking device passive as soon as the float rises above the locked position in the casing subsequent to the opening of the air brake device of the buoy with the length of the spring blades being such that when the spacer is pushed down into the casing until it touches a stop integral with the plunger, the second ends of the spring blades escape from the openings of the casing to thereby release the float from the plunger.