A machine comprises a first ground engaging unit connected to a first leg, a second ground engaging unit connected to a second leg, and a hydraulic system to control heights of the legs, the hydraulic system comprises a fluid circuit to control fluid between the first and second legs, a load holding valve to allow fluid into the fluid circuit, a control valve system to let fluid into the load holding valve, the control valve connected to a hydraulic fluid source and a reservoir, a first lock valve to control flow of fluid between the first and second legs in a first direction, a second lock valve to control flow of fluid between the second and first legs in a second direction, and first and float valves configured to connect the first and second legs to the control valve system, respectively.

A machine comprises a frame, a plurality of ground engaging units, a plurality of moveable legs, and a hydraulic system. A first ground engaging unit and a second ground engaging unit connect a first leg and a second leg, respectively, with the frame. The hydraulic system controls heights of the plurality of moveable legs. The hydraulic system comprises a fluid circuit to control fluid between the first and second legs, a load holding valve to control fluid flow into the fluid circuit, and first and second relief valves to control flow of fluid between the first and second legs in opposite directions. A method for controlling slope of a construction machine comprises activating a relief valve connecting right and left lifting cylinders to control flow of hydraulic fluid between the lifting cylinders to control retraction of one of the lifting cylinders from retracting.

A track system comprising a dynamic tensioning device located between an idler wheel and the support frame as to apply proper tension in the track. The dynamic tensioning device is adapted to block at its current length upon the occurrence of a determined condition. The dynamic tensioner is adapted to substantially maintain its length when an acceleration and or deceleration of the track system reaches a predetermined value. For instance, such characteristic is relevant in an event of emergency braking. A dynamic tensioner would become contracted and the tension in the endless track would become too low. A low tension could cause the endless track to ratchet.

A track system for use with a towed vehicle has an attachment assembly and a multi-member frame assembly. The multi-member frame assembly includes a primary frame member connected to the attachment assembly, at least one wheel-bearing frame member pivotably connected to the primary frame member about a pivot located within a recess, and at least one resilient bushing assembly located within the recess and engaging the pivot. The at least one bushing assembly is resiliently deformable in a circumferential direction to permit pivoting of the pivot with respect to the recess, and is fixedly connected within the recess to resiliently bias the pivot towards a rest position with respect to the recess. The track system further includes leading and trailing idler wheel assemblies rotatably connected to the at least one wheel-bearing frame member, and an endless track.

A tracked ATV includes a frame, a track coupled to the frame, and a power source supported by the frame and drivingly coupled to the track. The tracked ATV further includes a steering and drive assembly, which has a first hydraulic pump coupled to the tracks for large radius turns. The steering and drive assembly also has a second hydraulic pump coupled to the tracks for small radius turns.

A damping control system for a vehicle having a suspension located between a plurality of ground engaging members and a vehicle frame includes at least one adjustable shock absorber having an adjustable damping characteristic. The system also includes a controller coupled to each adjustable shock absorber to adjust the damping characteristic of each adjustable shock absorber, and a user interface coupled to the controller and accessible to a driver of the vehicle. The user interface includes at least one user input to permit manual adjustment of the damping characteristic of the at least one adjustable shock absorber during operation of the vehicle. Vehicle sensors are also be coupled to the controller to adjust the damping characteristic of the at least one adjustable shock absorber based vehicle conditions determined by sensor output signals.

Provided herein are a suspension apparatus and a specialized vehicle including the same. The suspension apparatus includes a crankshaft fixed to a vehicle body, a housing rotatably connected to the crankshaft, a first damping portion arranged in the housing and having a damping fluid accommodated in the first damping portion, an amount of the damping fluid in the first damping portion being adjusted according to an external force applied to the vehicle body, a second damping portion arranged in the housing, connected to the first damping portion such that the damping fluid moves between the first damping portion and the second damping portion, and including: a first space accommodating a compressed gas; and a second space accommodating the damping fluid, the first space facing the second space; and a rotational force applier arranged in the housing and configured to apply a rotational force to the housing by adjusting an amount of a working fluid in the rotational force applier.

A multi-functional off-road vehicle has a frame which includes a left lateral frame member and a right lateral frame member. The two frame members are connected by a crossbar. Four wheel assemblies are connected to the frame. At least two of the wheel assemblies are continuous tracks. The crossbar includes a track width adjustment actuator which extends and contracts a length of the crossbar and thereby changes a track width of the vehicle.

A milling machine may have a frame, a milling drum attached to the frame, and ground engaging tracks that support the frame and propel the milling machine in a forward or rearward direction. The milling machine may have height adjustable actuators connecting the frame to the tracks. Each actuator may have a cylinder attached to the frame, a piston slidably disposed within the cylinder, and a rod connected at a first end to the piston and connected to a track at a second end. The milling machine may have a tank storing hydraulic fluid and a fluid conduit connecting the tank to the cylinder. The milling machine may have a control valve selectively controlling a flow rate of the hydraulic fluid in the fluid conduit. The milling machine may also have a controller that determines a height of the frame relative to the ground surface based on the flow rate.

A milling machine may have a frame, first and second ground engagement members connected through respective, vertically adjustable leg columns to a front end of the frame, and third and fourth ground engagement members connected through respective, vertically adjustable leg columns to a rear end of the frame. Each vertically adjustable leg column includes a hydraulic cylinder connecting the frame and the associated ground engagement member. A milling drum is attached to the frame between the front and rear ends. At least one pair of the leg columns connected to the front end of the frame or the leg columns connected to the rear end of the frame includes an accumulator associated with each of the at least one pair of leg columns, a fluid conduit fluidly connecting a bore end of each of the hydraulic cylinders to the associated accumulator, and a control valve disposed in the fluid conduit and configured to control a flow of fluid between the hydraulic cylinders and the associated accumulators.