CPC Subgroup
G01P 3/24 by using friction effects (G01P3/06 takes precedence)
Full Title
Measuring linear or angular speed; Measuring differences of linear or angular speeds (G01P5/00 - G01P11/00 take precedence; ; counting mechanisms G06M) > Devices characterised by the use of mechanical means > by using friction effects (G01P3/06 takes precedence)