Anti-skid system for the driving wheels of automotive vehicles

Claim 1

An anti-skid system for a motor vehicle having an ignition system, a driving wheel and a non-driving wheel, said anti-skid system protecting the driving wheel from skidding, said anti-skid system comprising a first sensor for generating a number of pulses proportional to the peripheral distance traveled by the driving wheel, a second sensor for generating a number of pulses proportional to the peripheral distance traveled by the non-driving wheel, the second sensor generating a higher number of pulses than the first sensor for the same peripheral distance traveled by the respective driving and non-driving wheels, and a calculating unit means, responsive to the signals generated by said first and second sensors, for detecting the difference in peripheral distance traveled by the driving and non-driving wheels independently of time, said detecting means including means for producing a delay in the ignition system when said difference in peripheral distance traveled is greater than a predetermined value to adjust engine torque and to maintain optimum road adherence of the wheels and wherein said detecting means includes means for constantly comparing the pulses generated by the first sensor and the pulses generated by the second sensor, said comparing means including a counter connected to said first and second sensors wherein when the number of pulses generated by said second sensor exceeds the number of pulses generated by said first sensor, said counter is in a zero condition and when said counter receives a number of pulses from said first sensor which is greater by a predetermined amount than the number of pulses received from said second sensor, said counter generates a first signal, said detecting means also including a first monostable multivibrator for receiving said first signal, an ignition signal shaping circuit for generating an ignition signal, a time lag circuit, connected to said ignition signal shaping circuit, for generating a delayed ignition signal, and a switching logic circuit having inputs connected to each of said first monostable multivibrator, said ignition signal shaping circuit and said time lag circuit, said switching logic circuit being controlled by said delayed ignition signal when said first signal is applied to said first monostable multivibrator.