Seat belt buckle with inertia locking mechanism

Apparatus comprising:

• a vehicle seat belt buckle having first locking means for releasably locking a seat belt tongue in said buckle, said first locking means comprising a movable latch member having a locking position for engaging the tongue to block removal of the tongue from the buckle, a spring, and a pushbutton for moving said latch member from said locking position to a non-locking position against a bias of said spring;
• said buckle further comprising second locking means for blocking movement of said latch member from said locking position to said non-locking position upon the occurrence of a predetermined amount of deceleration of said buckle;
• said second locking means comprising a blocking structure which moves into blocking contact with said latch member in response to said predetermined amount of deceleration, said blocking structure moving pivotally into said blocking contact with said latch member;
• said second locking means further comprising an inertia mass structure, bearing means for supporting said inertia mass structure for pivotal movement in response to said deceleration of said buckle, and shaft means for moving said blocking structure pivotally in response to said pivotal movement of said inertia mass structure, said bearing means supporting said shaft means for rotation about a longitudinal central axis of said shaft means, said blocking structure and said inertia mass structure both projecting radially from said shaft means and being fixed to said shaft means for pivotal movement about said axis upon rotation of said shaft means about said axis, said blocking structure being one of a pair of substantially identical blocking structures projecting radially from said shaft means at locations that are spaced axially from each other, said inertia mass structure being one of a pair of substantially identical inertia mass structures projecting radially from said shaft means at locations that are spaced axially from each other.

Apparatus comprising:

• a vehicle seat belt buckle having first locking means for releasably locking a seat belt tongue in said buckle, said first locking means comprising a movable latch member having a locking position for engaging the tongue to block removal of the tongue from the buckle, a spring, and a pushbutton for moving said latch member from said locking position to a non-locking position against a bias of said spring;
• said buckle further comprising second locking means for blocking movement of said latch member from said locking position to said non-locking position upon the occurrence of a predetermined amount of deceleration of said buckle;
• said second locking means comprising a blocking structure which moves into blocking contact with said latch member in response to said predetermined amount of deceleration, said blocking structure moving pivotally into said blocking contact with said latch member;
• said second locking means further comprising an inertia mass structure, bearing means for supporting said inertia mass structure for pivotal movement in response to said deceleration of said buckle, and shaft means for moving said blocking structure pivotally in response to said pivotal movement of said inertia mass structure, said bearing means supporting said shaft means for rotation about a longitudinal central axis of said shaft means, said blocking structure and said inertia mass structure both projecting radially from said shaft means and being fixed to said shaft means for pivotal movement about said axis upon rotation of said shaft means about said axis, said blocking structure and said inertia mass structure projecting radially from said shaft means at locations that are spaced axially from each other.