Switching mechanism

摘要

A switching mechanism for incrementing are decrementing a value of a controlled parameter in response to movement of a controlling means, said movement being controlled in discreet amounts by detent means which comprises at least two spaced apart detent cam followers (1,2) operable to bear against and move relative to a toothed detent cam profile (4) and wherein the separation of the at least two detent cam followers is such that they act on the toothed detent cam profile to bias or urge relative movement in opposite directions.