Tire pressure drop warning apparatus

Claim 1

A tire pressure drop-warning apparatus for a vehicle, which apparatus is provided in an air chamber defined by a pneumatic tire and a wheel rim assembled with said pneumatic tire so as to mechanically strike said wheel rim for emitting an alarm-giving sound when the tire inner pressure drops in said air chamber below an allowable limit, comprising in combination: a securing member secured to said wheel rim; a blow-striking hammer provided spacedly from said securing member in the direction perpendicular to the radial direction of said wheel rim; and a connecting member made of a resilient material and having one end connected with the radially outer end of said securing member and the other end connected with said blow-striking hammer; said blow-striking hammer having at its radially outer end a protrusion extending radially outwardly from the radially outer end of said connecting member said blow-striking hammer having at its radially inner end a blow-striking portion for striking said wheel rim, so that when the wheel is rotated in use the inner surface of said pneumatic tire is periodically brought into pressed engagement with the radially outer end of said protrusion if when said tire inner pressure is dropped in said air chamber below said allowable limit the connecting member is thereby caused to be shearingly and bendingly deformed so that the blow-striking portion will strike said wheel rim to themselves alone emit said alarm-giving sound discernable over other noises of said vehicle.