Patent GB-1471074-A (GB)
Title: Method and apparatus for preventing spinning of a driving wheel  of a motor vehicle
IPC: B60K28/16
Filed: 1974-08-22
Abstract: 1471074 Timing ignition; regulating I C engines SOC ANON DBA 22 Aug 1974 [14 Sept 1973] 36998/74 Heading F1B [Also in Divisions F2 and G3]  Signals representative of the speed of the driving wheels 18 and of the non-driving wheels 22 of a vehicle are used to slow the driving wheels 18 to prevent spinning thereof - such slowing can be brought about by controlling the vehicle's engine, ignition or timing or carburettion, by means of a signal from a point A of a logic control element 62. In one embodiment a relay operable by the logic element switches off the ignition intermittently. In a variant an electromagnet changes the ignition timing by altering either the automatic ignition advance or the ignition timing angle. In a further embodiment a signal from A is applied to a normally closed solenoid valve situated, for example, between the carburetfer intake pipe and the air filter, and operable to affect richness of the mixture by opening an air inlet downstream of the carburetter. The element 62 is supplied with signals from sensor/converter assemblies 64, 66 on the driving wheels 18 and non-driving wheels 22 respectively - these assemblies generate signals whose frequency represents the rotational speed of the associated wheel, and these frequency signals are then converted to voltage signals. Each voltage signal from a converter 64 is fed to a transistor 72, and the voltage at B represents the speed of the faster driving wheel. The transistors 72 are connected by way of a variable resistance 74, a resistance 76 and a resistance 78 to a comparator 80. The value of the resistance 74 is dependent on the vehicle speed represented, for example, by the output voltages from the assemblies 66 - the voltage at D is therefore equal to the voltage at B less a first fixed difference and less a variable difference. The signals from assemblies 66 are fed to transistors 92, and the transistors 92 and a transistor 90 connected to point D are interconnected at F - the voltage at F is the greatest of the voltages applied to the bases of transistors 90, 92. The point F is also connected via a resistance 94 to the comparator 80 and when the voltage at D becomes greater than that at F, a voltage pulse appears at point A to energize the winding 60. The logic element 62 also includes a capacitor 106, and a constant-current circuit 108 arranged in parallel between point F and earth, and a diode 96 between point D and point F. When during an anti-spin cycle, the voltage at D begins to decrease the circuit 108 supplies a constant current at F with the result that the voltage at F decreases linearly following the discharge of the capacitor 106. When the voltage at F is greater than the voltage at D by a value corresponding to the resistance of diode 96, the latter becomes conductive and the voltage at F decreases with the voltage at D until the voltage at F becomes equal to the voltage representing the faster non-driven wheel. The element 62 also includes a threshold circuit 98 including a transistor 100 which becomes conductive when the voltage at E reaches a high level caused by the speed of the driving wheels becoming excessively high. E is therefore earthed and the capacitor 106 discharges to circuit 108, and the voltage at F decreases linearly.