Overdrive for motor vehicles

In an overdrive for motor vehicles, comprising a housing, a planetary carrier which is joined to an input shaft, a ring gear with internal teeth, which ring gear engages planet pinions carried on the planet carrier and is joined to an output shaft, a sun pinion engaging the planet pinions, and a main gear box coupled to the overdrive, said main gear box providing four forward gears and neutral, in addition to said overdrive;

• the improvement comprising a one-way clutch (12,42) that is coupled in-between the housing (11,33) of the overdrive and the sun pinion (8, 40), said one-way clutch being arranged to lock the sun pinion to the housing when driving torque is transmitted from the input shaft to the output shaft, a second clutch (16,18;
• 55,56) which establishes, when engaged, a non-turnable connection between the sun pinion and the ring gear, the one-way clutch having control means (13,50) which cooperate with operating means (21b,64) for the second clutch to suspend the blocking function of the one-way clutch before the second clutch is engaged, the one-way clutch (42) having an interior clutch member (44) with cavities (45) distributed around its periphery, which hold spring biased locking members (47) which are disposed to block an outer clutch member (43), concentric with the inner clutch member against rotation in one direction, the control means of the one-way clutch comprising a rotatably journalled sleeve (50) with a plurality of axial pins (52) which extend into individual cavities (45) in the inner clutch member (44) and are disposed when the sleeve (50) is turned to a disengaging position, to block the locking members (47) and prevent them from locking the outer clutch member (43) so that it is freely rotatable in both directions relative to the inner coupling member.