Push button buckle assembly for a seat belt

A seat belt buckle assembly capable of positive and quick release engagement with a tongue, the buckle assembly comprising:

• (a) a base having a front end through which the tongue is inserted in and withdrawn from the buckle assembly, and a rear end opposite the front end, the base comprising a generally flat major portion of generally rectangular shape and a pair of opposed side walls provided on and extending along the opposite sides of the major portion, the side walls having therein means defining a first pair of opposed apertures located intermediate the front and rear ends of the base and means defining a second pair of opposed apertures which open at the front end of the base;
• (b) a latch having a pair of opposite ends engaged in the first pair of apertures in the side walls of the base for pivotal motion about a first axis, which extends through the center of gravity of the latch, relative to the base between a latching position for positive engagement with the tongue inserted in the buckle assembly and an unlatching position for releasing the tongue;
• (c) a push button generally overlying the latch and having a pair of trunnions projecting laterally from the front end of the push button, the trunnions being inserted rearwardly into the second pair of apertures and being rotatably engaged in the side walls of the base for pivotal motion about a second axis, which extends parallel to the first axis, relative to the base between a normal position for holding the latch in the latching position and a working position for holding the latch in the unlatching position;
• and
• (d) a dual-purpose integral spring mounted on the base and disposed between the latch and the push button, the dual-purpose spring having a first spring portion extending laterally of the base between the opposed side walls thereof for connecting the spring to the base and acting directly on the latch for normally urging the latch in the latching position, a second spring portion protruding forwardly with respect to the first portion and acting directly on the push button for normally urging the push button in the normal position, and a mid spring portion interconnecting the first and second spring portions, the mid spring portion comprising a pair of wings extending laterally of the base, each wing having a pair of opposed leg portions extending laterally in the widthwise direction of the base, one end of one leg portion being connected to the first spring portion and the corresponding one end of the other leg portion being connected to the second spring portion, and a connecting portion interconnecting the other ends of the pair of leg portions;
• (e) the push button being operative when pushed manually from the normal position to the working position against the force of the dual-purpose spring to act directly on the latch for pivoting the same from the latching position to the unlatching position against the force of the dual-purpose spring.