Traction control apparatus

Abstract

A traction control system is disclosed for use with a vehicle braking system including a plurality of driven wheels connected by differential means, wheel brake means associated with each driven wheel, and spring brake-operating means for operating each of the wheel brakes, respectively, each of said spring brake means including a brake diaphragm operable between brake-engaged and brake-released positions, a locking spring operable to place the brake diaphragm in the brake-engaged position, and a spring diaphragm operable between a normal spring-disabling position and a spring-enabling position in which the locking spring is inoperative and operative, respectively; characterized by the provision of means for generating for each driven wheel a velocity sensing signal, comparison circuit means for comparing said sensing signals to produce a control voltage when the rotational velocity of one driven wheel exceeds another by a predetermined amount, and means operable by said control signal for placing in the spring-enabling position the spring diaphragm associated with the faster driven wheel, thereby to effect braking of the faster driven wheel and to produce transfer of driving torque to the slower driven wheel. Furthermore, the invention has utility in conjunction with tandem wheel vehicles including pairs of said driven wheels which are connected through interaxle differential means, means being operable when the velocity of one pair of driven wheels exceeds another by a predetermind amount for placing in the spring-enabling positions the spring diaphragms associated with the wheels of the faster driven wheel pair.