Vehicle with four wheel drive transmission - has parking brake applied via all four wheels to improve stability

摘要

The two axles are linked by a main differential and by a clutch. For single axle drive the main differential is blocked and the clutch (5) open. For four wheel drive the clutch is closed and the differential is operative to spread the torque. An improved park setting has the differential blocked to provide the blocked setting for all four wheels. The failsafe park setting is operated by a brake lever. A failsafe additional feature prevents instability if the parking brake is applied during travel. An actuating member for switching off of the blocking clutch (5) is connected to a 3/2-way electromagnetic switching valve (27), which is electronically controlled (12). ADVANTAGE - Safe parking on sloping ground, improved stability.