Vehicle automatic gearbox moment measurement on fixed parts - is by determining stress in or deformation of supporting couplings linking fixed gear stage to housing

The method is for measuring the torque of a drive system, esp. the automatic gearbox of a vehicle combustion engine, and involves making measurements only on non-rotating parts and gives results independent of temp. and geographical altitute. The movement generated in an element supporting the gearbox on its mounting is measured and multipled by a proportionality factor related to the known transfer ratio of the gearbox or stage. This enables indication of the transmission ratio. The moment in a coupling linking a fixed gear state to the housing is measured and compared with a defined threshold level to produce a switching signal. The moment may be determined by measuring the mechanical stress in a deformation of the gearbox housing or an attachment.