Improvements in devices for detecting abnormal condi- tion of a pneumatic

摘要

An abnormal tire condition warning system is disclosed for use in pneumatic tires. The self-contained device comprises a sensor (16), an electronic transmitter (18, 22) and a power supply (24). The power supply is a weighted (30), vibrating arm (26) that has a piezoelectric transducer (32) attached. Normal wheel vibrations cause the weighted arm to vibrate and flex, in turn causing the transducer to flex, thus producing electrical energy which is used to power the transmitter circuitry. The vibrating arm may be fixed at each end and weighted at the centre, as in Figures (not shown), or fixed at the centre and weighted at each end as in Figure 6 (not shown). IMAGE