Dispositif de verrouillage agissant en fonction de la vitesse afin d'empêcher de rétrograder indûment, utilisable dans le mécanismes de changement de vitesse de véhicules automobiles

摘要

A fluid-control transmission lock is provided to prevent unwanted downshifting of a multiple-speed transmission and especially a servocontrol or power-assist transmission. The lock is speed-responsive and prevents, for example, the spontaneous downshifting from one speed range to another or from a higher gear ratio within a particular range to an impermissibly lower gear ratio within that range, in accordance with the vehicle speed.