A buckle for a safety belt with three branches where one of the branches includes a rocking lever, which is pivotably connected at one end, having an opposing free end, an intermediate groove and an intermediate projection. A dependent portion or
appendage of a
push button is provided including a V-shaped notch with a
cam surface that cooperates with the intermediate projection of the lever. When the buckle device is un-buckled, the
push button is kept at a resting position by the intermediate projection of the lever movement along the
cam surface and into the V-shaped notch, where the lever is prevented from rotating but is oscillated about its pivot. The arrangement of the oscillating lever during
insertion of a pair of tongue members within a
casting seat or cavity prevents a corresponding clamp member (pawl) from prematurely or improperly engaging a side notch of a respective tongue member until the proper alignment /
insertion of the tongue members is complete at which time the lever is free to rotate (via the intermediate groove) allowing the pawl to fully engage the notch correctly. Conversely, when the
push button is pressed, a spring biased ejector block extracts the tongue members from the seat or cavity of the casing and the release button is brought back into its resting position.