The distance of each roller from the rotation axis and {HEAD ~ the angles} between {TAIL ~ adjacent rollers} are predetermined such that, at any time during a rotation cycle, two rollers engage at least one currently active tooth 
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The distance of each roller from the rotation axis and { HEAD ~ the angles } between { TAIL ~ adjacent rollers } are predetermined such that , at any time during a rotation cycle , two rollers engage at least one currently active tooth
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH