Speed change detecting device for controlling a clutch associated with a gearbox

摘要

A device detects forces in a gearbox operating linkage in order to control an automatic clutch operating system for the purpose of changing the gear ratio. The linkage comprises a shaft in the gearbox adapted to rotate between two limiting positions corresponding to selection of respective different gear ratios. It also comprises a deformable linkage element in the force detecting device adapted to move between two limiting positions corresponding to the limiting positions of the shaft. This deformable linkage element comprises two portions coupled together elastically by an elastic return device. The force detecting device comprises a speed parity detector adapted to assume a parity state representing the position of the shaft and varying according to which of its limiting positions the shaft is in. It also comprises a force direction detector associated with the deformable linkage element adapted to assume a state representing the configuration of this element, which varies according to whether the element is loaded in one or the other of two reference directions. These reference directions respectively correspond to movement of the deformable linkage element from one to the other of its limiting positions and vice-versa. The parity detector and force direction detector are connected to a processor circuit adapted to activate the automatic clutch operating system to disengage the clutch when the deformable linkage element is loaded in a direction tending to move the shaft to an unoccupied limiting position.