B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
B62M3/00—Construction of cranks operated by hand or foot
B62M3/02—Construction of cranks operated by hand or foot of adjustable length
B62M3/04—Construction of cranks operated by hand or foot of adjustable length automatically adjusting
Outil a moteur a deux vitesses dont le passage d'une vitesse a l'autre est effectue automatiquement par un dispositif a came, tel que perceuses ou analogues