Seat belt tongue

1. A seat belt system for use in a vehicle, comprising:

a seat belt webbing for restraining an occupant of the vehicle, wherein the webbing includes a first end and a second end, wherein the first end of the webbing is attached to a retractor for either retracting the webbing or permitting withdrawal of the webbing, and wherein the second end of the webbing is connected to an anchor;

a tongue mechanism connected to the webbing and positioned to separate the webbing into a lap portion and a shoulder portion;

a buckle mechanism configured to detachably couple with the tongue mechanism;

wherein the tongue mechanism is configured so that the tongue mechanism is slideably coupled to the webbing when the tension in the webbing is less than a cinching load, and when the tension in the webbing is equal to or greater than the cinching load the tongue mechanism applies a cinching force on the webbing to prevent the webbing from changing position relative to the tongue mechanism,

wherein the tongue mechanism is configured so that when the tension in the webbing is less than the cinching load there is no cinching force applied to the webbing, and

wherein the tongue mechanism includes a first biasing member and a second biasing member, wherein the second biasing member is for biasing a cinch plate into a position that permits relative movement between the webbing and the tongue mechanism and wherein the tongue mechanism is configured so that when the tensile force on the webbing drops below the cinching load after having previously exceeded the cinching load the second biasing member forces the cinch plate into a position wherein a blocking member can be forced into a first position by the first biasing member.

2. The system of claim 1 , wherein each of the first and second biasing members comprise one of a coil or a plate spring.

3. The system of claim 1 , wherein the tongue mechanism includes a tongue plate and wherein the cinching force on the webbing is applied by changing the position of the cinch plate relative to the tongue plate.

4. The system of claim 3 , wherein the blocking member is located in the first position to prevent relative movement between the cinch plate and the tongue plate and wherein the tongue mechanism is configured so that the position of the blocking member changes from the first position to a second position when the tensile force on the webbing meets or exceeds the cinching load to thereby permit relative movement between the cinch plate and the tongue plate.

5. The system of claim 4 , wherein the first biasing member is for biasing the blocking member from the second position into the first position.

6. The system of claim 4 , wherein the tongue mechanism further includes a cover member having a recess on a bottom surface of the cover, wherein the recess includes a width configured to receive the length of the first biasing member, a depth configured to receive the first biasing member and a length configured to receive the length of the blocking member.

7. The system of claim 4 , wherein the cinch plate includes a base surface, and a cam surface extending from the base surface.

8. The system of claim 7 , further comprising a plateau surface extending from the base surface and wherein the blocking member is located flush with or above the plateau surface when the blocking member is in the second position.

9. The system of claim 7 , wherein the blocking member contacts or is proximate to the cam surface when the blocking member is in the first position.