US Patent 11111120 Leveling system for lift device

A lift device includes a chassis having a first end and an opposing second end, a first actuator coupled to the first end, a second actuator coupled to the first end, a third actuator coupled to the opposing second end; and a fourth actuator coupled to the opposing second end. The first actuator and the second actuator are selectively engageable to facilitate providing active control of a first pitch adjustment and a first roll adjustment of the first end of the chassis. The third actuator and the fourth actuator are (i) selectively fluidly couplable to facilitate providing passive control of a second pitch adjustment and a second roll adjustment of the opposing second end of the chassis and (ii) selectively fluidly decouplable to facilitate providing active control of the second pitch adjustment and the second roll adjustment of the opposing second end of the chassis.