Apparatus for measuring the slip of locomotive wheels and preventing sliding thereof

Apparatus for measuring wheel slip and to prevent excessive sliding of the wheels of a locomotive and which produces a control signal in accordance with the variation in velocity between translatory speed of the locomotive and the circumferential velocity of sliding sheels, said control signal being used for governing the speed of the locomotive, said apparatus comprising:

• a system including a coupling loop for determining the effective acceleration of the locomotive, said system comprising a comparator into one input of which is fed a signal corresponding to the acceleration of a wheel and wherein the output signal from said system is fed back to the other input of said comparator and wherein the following seriately connected circuit components are included between said comparator and the output of said system.
• 1. a switch which opens only in the event of wheel slip,
• 2. an integrator with output storage,
• 3. a multiplier having one input thereof connected to the output store of said integrator and to the other input of which is connected a signal derived from the locomotive motor current and which is proportional to its pulling force, said system being in balance when said switch is in its closed state and which is indicative of an effective acceleration of the locomotive equal to that of the wheel acceleration, means for integrating the difference between a signal
• representing the output from said system by which the effective acceleration of the locomotive is obtained and a signal representative of wheel acceleration to produce said control signal for governing the speed of the locomotive,
• and means for blocking transmission of said difference signal to said integrating means in the absence of wheel slip.