Variable-geometry and gliding-flight device for helicopter toys, equipped with a takeoff convenience device giving rise, at the appropritate moment and in an autonomous manner, without a land link, to a considerable increase in the length and a variation in the angle of incidence of the propeller blades

摘要

Various elastic forces established before takeoff and which tend to vary the geometry of the blade are momentarily prevented by oppositions. These forces and oppositions are imbricated in a chain of which the last link is a bolt 57 which prevents a shuttle 51 from being driven towards the left of the diagram by means of a centripetal elastic force 56, which, by preventing the geometry from varying prematurely, enables the toy to take off. During flight, as the centrifugal force 74 of the shuttle 51 is greater than the force 56 driving the shuttle 51 towards the right, this gives rise to the retreat of the bolt 57. When, next, as the rotational speed decreases, the centrifugal force 74 becomes less than the centripetal force 56, the shuttle 51 which can no longer be stopped by the bolt 57 which is absent is freely driven towards the left and releases the elastic forces established before takeoff as a chain reaction, which forces then vary the geometry of the blade. <IMAGE>