Buckle for retarded automatic unlocking of safety belts and harnesses of parachuting equipments and of vehicles

A buckle for retarded automatic unlocking the shackle of safety belts and harnesses, said buckle comprising:

• a casing for receiving the shackle;
• a frame means slideably mounted with respect to said casing and including a frame means return spring connected to said casing for biasing said frame means to an initial position;
• a shaft mounted through said frame means;
• a bolt rotatably mounted on said shaft for releasably engaging and locking the shackle;
• an automatic unlocking control rotatably mounted on said shaft and engaging said bolt for disengaging said bolt from the shackle for unlocking the shackle from said bolt;
• an auxiliary locking means including a movable means supported by said frame means and releasably engaging and locking said automatic unlocking control so as to block rotation of said control to prevent unlocking the shackle from said bolt;
• at least one drive spring, connected to said movable means, compressed by the shackle when the shackle is inserted into said casing and biasing said movable means for movement out of engagement with said automatic unlocking control for unlocking said automatic unlocking control
• said auxiliary locking means further including a movable latch means withdrawably abutting said movable means for securing said movable means against the biasing of said drive spring and a brake means connected to said movable means for retarding rapid acceleration of said movable means under the urging of said drive spring when said movable latch means is withdrawn from abutting said movable means;
• whereby said automatic unlocking control is slowly unlocked under the action of a traction force exerted by the shackle on said bolt, which traction force is sufficient to slideably move said frame means against the bias of said frame means return spring, said frame means return spring returning said frame means to its initial position as soon as the traction force of the shackle on said bolt substantially diminishes.