Abstract: A suspension system for a heavy duty crane, excavator or the like is provided with a transverse rear axle and semi-independent suspension by hydraulic cylinders. The cylinders are pivotally attached adjacent the ends of the axle to allow oscillation in a traveling mode simulating a bolster, center pinned type system. The extend sides of the cylinders transfer hydraulic oil through an exchange line to accommodate true oscillation movement. In a working mode, locking valves block the flow of oil between the cylinders to establish a stabilized platform. A hydraulic/pneumatic accumulator communicates with the exchange line in the travel mode for cushioning of the ride. A third locking valve in a bypass return line communicating with the retract sides of the cylinders blocks the oil flow back to the reservoir in the working mode, but upon release by the control circuit is opened to communicate with the reservoir and maintain back pressure to enhance oscillation and prevent cavitation.

Abstract: A vehicle roll rigidity control device comprises a control unit and an actuator which can adjust an attenuation force installed between the vehicle front wheel and body. The control unit reduces the attenuation force of the actuator and increases the ability of the vehicle to turn around when the vehicle is in a turn transient state. When the sequential steering operation to the left and right is performed, the controller increases the attenuation force of the actuator and increase the roll rigidity of the front wheels.

Abstract: An apparatus for controlling pivoting of a forklift rear axle. A hydraulic damper is arranged between a rear axle and a forklift body. The damper includes two oil chambers. The oil chambers are connected to a first passage and a second passage. A two-way switch valve is arranged between the oil chambers. The valve permits the flow of oil between the oil chambers and allows pivoting of the rear axle when opened. The valve restricts the flow of oil between the oil chambers and prohibits pivoting of the rear axle, thereby locking the rear axle when closed. When the rear axle is released from a locked state, the valve repeats a valve cycle, which includes opening and closing the valve, to regulate the amount of fluid that flows between the chambers. The valve is then kept in an opened state. This prevents shock that may be produced by sudden tilting of the body when the rear axle is released from a locked state.

Abstract: A utility vehicle ha a rigid axle that can be pivoted about a fixed swivel extending the longitudinal direction of the vehicle. The axle is mounted on a swinging link, with which the cylinder of a hydro-pneumatic spring suspension engages. Such vehicle are equipped with a spring suspension for road travel at speeds in excess of 40 km/hr. However, both the spring action and the swivel movement of the rigid axles are potentially dangerous when working on uneven or sloping ground. This invention permits both the spring action and the swivel movement of the rigid axle to be prevented. This invention is particularly well suited for vehicles used in agriculture, forestry, and construction.

Abstract: An apparatus for controlling pivoting the rear axle of a forklift. The forklift includes forks, which are lifted and lowered relative to a body frame. A locking mechanism, which includes a hydraulic damper and an electromagnetic valve, locks the rear axle to stabilize the body frame. A controller controls the locking mechanism to lock the rear axle when the fork height is at least as great as a predetermined height threshold value and the weight of a load on the fork is at least as great as a predetermined weight threshold value. The controller also controls the locking mechanism to lock the rear axle when the lateral acceleration is at least as great as a predetermined threshold value. Further, the controller changes the threshold value of the lateral acceleration in accordance with the fork height.

Abstract: A method for detecting laterally inclined bends being traversed by a vehicle uses a bend-specific value, such as the rotation rate, lateral acceleration or steering angle of the vehicle, the bend-specific value being simultaneously determined by a plurality of different measuring systems. The plurality of determined values are sorted by magnitude to obtain an indication of whether a laterally inclined bend is being encountered by the vehicle.