Ramp Locking Differential With Tone-Wheel Lock Detection

The patent introduces tone wheels with teeth as intermediary components that convert the mechanical lock status into detectable positional signals. The first tone wheel is attached to the differential case and the second tone wheel to the ramp plate, serving as mediators between the locking mechanism and the detection system. This allows indirect detection of lock status through relative position sensing without directly monitoring the locking components themselves.

The patent replaces complex mechanical telemetry systems with an optical/electromagnetic sensing approach. Instead of using mechanical linkages or electrical contacts to detect lock status, the system uses pickup sensors to detect the positions of tone wheels and generate voltage pulses. This substitution reduces mechanical complexity while providing reliable lock status detection.

The patent implements a feedback mechanism where pickup sensors continuously monitor the positions of the tone wheels and generate voltage pulses that indicate lock status. The controller receives these pulses and determines whether the differential is locked or unlocked based on the phase relationship between pulses from the two sensors. This feedback loop provides accurate, real-time lock status detection without requiring complex telemetry infrastructure.

The patent uses tone wheels with teeth as simplified copies or representations of the actual locking mechanism state. Instead of directly sensing the complex interaction between locking components, the system creates a simplified angular position copy through the tone wheels that can be easily detected by pickup sensors. This copying approach maintains detection accuracy while dramatically reducing system complexity.