Indicator for rotary positioner

A position indicator for a shaft rotatable about an axis, the indicator comprising:

• a housing fixed adjacent the shaft;
• a predetermined number n of indicia on the housing angularly equispaced about and radially equispaced from the axis;
• an eccentric disk fixed on the shaft and having a circular outer periphery that is eccentric to the axis;
• an inner indicator ring carried on the periphery of the eccentric, having a circular outer periphery with a circumference c, and formed offset from the axis with an axially throughgoing inner aperture axially alignable with the indicia;
• a circular track on which the periphery of the inner indicator plate rides and having a circumference C greater than the circumference of the inner-ring periphery, the ratio of the circumferences being such that:
• c/C=1-1/n,
• an outer indicator disk fixed on the shaft adjacent the indicator ring and formed with an axially throughgoing outer aperture axially allowable with the indicia;
• and
• whereby the indicator ring rolls on the track as the shaft and eccentric rotate and the apertures align every (1-1/n) revolution and expose one of the indicia.