US Patent 7898139 Variable effort steering actuator

A magnetic actuator, comprising, an inner ring, an outer ring disposed around the inner ring, a first pair of inner teeth disposed on the inner ring that partially define a gap between the first pair of inner teeth having a first angular dimension, a second pair of inner teeth disposed on the inner ring that partially define a gap between the second pair of inner teeth having a second angular dimension, a first pair of outer teeth disposed on the outer ring that partially define a gap between the first pair of outer teeth having a third angular dimension and a second pair of outer teeth disposed on the outer ring that partially define a gap between the second pair of outer teeth having a fourth angular dimension.