Indicator for testing inertial reel seat belt operation - has metal ball displaced from rest to complete electrical circuit

摘要

The indicator circuit for testing inertial-reel seat belts in motor vehicles comprises a heavy ball (2) which normally rests in the centre of a metal ring (3) in a container. A second ring with slightly higher walls (4) encloses the first. Each ring is connected to a battery powered lamp and/or bell circuit (6-8) fitted to the vehicle or test rig. When the acceleration forces, produced by braking or cornering etc. reach the limits corresponding to those at which the locking mechanism in the inertia-reel safety belt should come into operation, the ball is displaced from its central position and bridges the gap between the two concentric rings. The electrical circuit is completed and the lamp/bell indicator is energised.