A suspension system for a land vehicle is provided with at least one actuator connected to a chassis and an axle of a land vehicle spaced apart from a pivotal connection of the axle. A suspension circuit is in cooperation with the at least one actuator. A controller is in operable communication with the suspension circuit and is programmed to receive input indicative of a travel speed of the land vehicle. The suspension circuit is closed at a low speed travel range to permit the axle to pivot in response to variations in an underlying support surface. The suspension circuit is opened to permit selective actuation of the at least one actuator at a higher speed travel range in response to variations in the underlying support surface.

Methods and systems for hydraulic vehicle suspension are provided. A hydraulic suspension system, in one example, includes a first manifold including a piston-side interface and a rod-side interface fluidically coupled to a piston chamber and a rod chamber, respectively, for each of a first hydraulic cylinder and a second hydraulic cylinder. In the system, the first manifold includes a first electrically activated valve fluidically coupled to the piston-side interfaces, a first damping device, and a second damping device, the first electrically activated valve is configured to lock and unlock vertical motion of the first and second hydraulic cylinders and, while vertical motion of the first and second hydraulic cylinders is locked, the first electrically activated valve permits fluidic communication between the first and second hydraulic cylinders to permit free roll motion in the hydraulic suspension system.

Embodiments of a suspension for a vehicle is provided. The suspension includes, for example, a frame and a locking assembly. The locking assembly inhibits tipping of a frame of the vehicle when tipping of the frame is detected.

A utility vehicle, in particular a firefighting vehicle, comprising an extendable aerial apparatus like a turnable ladder and/or an aerial rescue platform, a jacking system with lateral ground supports for jacking the vehicle body, and a stabilization mechanism for preventing tilting of the vehicle body in its jacked state. The stabilization mechanism includes a hydraulically operable rear axle blocking device for blocking the rear axle suspension of the vehicle. The stabilization mechanism further includes at least one hydraulically lockable shock absorber integrated into the front axle suspension of the vehicle. The rear axle blocking device and the hydraulically lockable shock absorber are controlled by a common hydraulic control to lock the hydraulically lockable shock absorber at the same time or with a delay after activating the rear axle blocking device.

Methods and systems for hydraulic vehicle suspension are provided. A hydraulic suspension system, in one example, includes a first manifold including a piston-side interface and a rod-side interface fluidically coupled to a piston chamber and a rod chamber, respectively, for each of a first hydraulic cylinder and a second hydraulic cylinder. In the system, the first manifold includes a first electrically activated valve fluidically coupled to the piston-side interfaces, a first damping device, and a second damping device, the first electrically activated valve is configured to lock and unlock vertical motion of the first and second hydraulic cylinders and, while vertical motion of the first and second hydraulic cylinders is locked, the first electrically activated valve permits fluidic communication between the first and second hydraulic cylinders to permit free roll motion in the hydraulic suspension system.

Disclosed are various embodiments, aspects and features an oscillating track system that includes an oscillating track lock subsystem. The oscillating track system may include a track operable to rotate around a housing structure that is configured to receive an axle. While in operation, i.e. while the track is being rotated around the housing, the oscillating track system may be able to oscillate about the axle and, in doing so, incline or decline to accommodate undulating terrain. Advantageously, when stopped, the degree to which the oscillating track system has oscillated around the axle may be locked in place via an oscillating track lock subsystem comprised within the oscillating track system, thereby providing stability to the heavy equipment that includes the oscillating track system.

Embodiments of a suspension for a vehicle is provided. The suspension includes, for example, a frame and a locking assembly. The locking assembly inhibits tipping of a frame of the vehicle when tipping of the frame is detected.

A fluid suspension system for a land vehicle is provided with an actuator connected to a chassis and an axle of a land vehicle spaced apart from a pivotal connection of the axle. A fluid pressure circuit is in cooperation with the at least one actuator. A controller is in operable communication with the fluid pressure circuit and is programmed to receive input indicative of a travel speed of the land vehicle. The fluid pressure circuit is adjusted to limit fluid flow rate or reduce fluid pressure at a low speed travel range to permit the axle to pivot in response to variations in an underlying support surface. The fluid pressure circuit is adjusted at a higher speed travel range for selective actuation of the at least one actuator or for a higher fluid pressure actuation of the at least one actuator, in response to variations in the underlying surface.

A suspension system for a land vehicle is provided with at least one actuator connected to a chassis and an axle of a land vehicle spaced apart from a pivotal connection of the axle. A suspension circuit is in cooperation with the at least one actuator. A controller is in operable communication with the suspension circuit and is programmed to receive input indicative of a travel speed of the land vehicle. The suspension circuit is closed at a low speed travel range to permit the axle to pivot in response to variations in an underlying support surface. The suspension circuit is opened to permit selective actuation of the at least one actuator at a higher speed travel range in response to variations in the underlying support surface.

A spring configuration comprises a cylindrical damper (5), a primary coil spring (9) with a first predetermined spring rate K1, and a secondary coil spring (11) with a second predetermined spring rate K2, the coil springs arranged about the cylindrical damper (5) in series so as to provide a total combined spring rate KT, an actuator (20) configured to compress and decompress the coil springs (9, 11), a stop (12) configured to deactivate the secondary coil spring (11) at a stop position, such that, when the system is in a first, comfort, mode, the overall suspension spring rate is defined by the series equation 1/KT=1/K1+1/K2, and when the system is in a second, handling, mode, the overall vehicle suspension spring rate is defined by the series equation KT=K1, thus selectively and switchably providing both a low rate, optimal ride comfort setting and a high rate, optimal handling lower ride height setting.