摘要 |
The invention provides a deflation warning device for a pneumatic tire which gives a clear, positive indication of a predetermined pressure loss by the exposure of a brightly colored element within a transparent dome, all moving parts of the device being fully enclosed and protected against the ingress of dirt and corrosion by a housing. The element is either masked or unmasked by an opaque shield mounted on a piston which is biased by a spring to unmask the element but can be displaced by tire pressure acting on its surface to mask the element. In preferred embodiments of the invention the piston is located between the inner and outer parts of a second piston which is in turn responsive to tire pressure acting on its upper surface. |