Tire condition sensing apparatus

Apparatus for sensing the profile condition of a conventional vehicle wheel assembly having an axis of rotation comprised of a rim having an outer peripheral surface with outwardly extending radial flanges at the opposed side edges thereof and a pneumatic tire having an annular road-engaging tread surface with side wall portions at the side edges thereof defining a generally annular tire cavity with said tire adapted to be mounted on said rim and inflated to a predetermined pressure for supporting a vehicle with a predetermined maximum allowable tire profile deflection, said apparatus comprising:

• a sensing and actuating structure adapted to be operably mounted within said annular tire cavity including a body portion and a linkage portion comprising a flexible profile sensor having high flexfatigue characteristics, said linkage portion having a first normal position spaced from said tire when said tire profile deflection is less than said predetermined maximum and a second flexibly deflected position when said tire profile deflection is greater than said predetermined maximum, said linkage portion being forcibly moved from said first toward said second position by positive contact from said tire;
• energizing means comprising a piezoelectric generator associated with said body portion which is selectively movable between energizing and non-energizing conditions, said energizing means being in said non-energizing condition when said linkage is in said first normal position and being moved into said energizing condition as said linkage is moved toward said second position;
• and,
• means responsive to said energizing means for indicating that said tire has a profile deflection greater than said predetermined maximum allowable deflection.