A steering axle drive assembly includes a steering axle having opposite ends, a wheel pivotally connected with each steering axle end, and a control mechanism. The wheels are operated by the control mechanism for rotation about a vertical axis and a horizontal axis. When the axle is connected with a vehicle, the control mechanism controls the steering axle wheels independent of other wheels of the vehicle, such as the main drive wheels, to steer and drive the vehicle from an origin in any direction without passing through the origin. Preferably, a motor or linear actuator controls the rotation of the steering axle wheels. The steering axle drive assembly can be further improved by including an angled axle.

The disclosure relates to a steering control system useful for providing stable control during high-speed operation of harvesters, such as self-propelled windrowers. The steering control system utilizes sensors for detecting a ground drive wheel speed or a swash plate position of hydraulic pumps for determining an angle of curvature used as input for controlling a steering cylinder associated with a first caster.

A high clearance sprayer with a four-wheel steering system includes a steering input, a steering control system, a front steering system, and a rear steering system. The front and rear steering systems are mirrored images of one another, which simplifies and improves the accuracy of the four-wheel steering control methodology. In doing so, the control system may calculate a single value that is used for controlling the front steering system, and an inverse of the single value that is used for controlling the rear steering system. Both of the front steering system and the rear steering system include wheels, steering actuator systems, swingarms, and wheel supports, which all of position of the wheels relative to the sprayer to be rotated. The steering control system may allow for various steering maneuvers to occur, including a turn-steering maneuver and a crab-steering maneuver.

An all-wheel steer trailer having six wheels is disclosed. The trailer includes an elongated frame means having first and second frame members having forward and rearward ends. A pivotal axle support is positioned at the forward end of the trailer and has first and second wheels rotatably mounted thereto. An elongated tongue has its rearward end secured to the axle support for pivotally moving the axle support and the first and second wheels mounted thereon. A tandem axle assembly is mounted on the first and second frame members forwardly of the rearward ends thereof. The tandem axle assembly includes third, fourth, fifth and sixth wheels which are rotatably and pivotally secured to the frame means. When the first and second wheels are pivotally moved in one direction, the third, fourth, fifth and sixth wheels are pivoted in an opposite direction.

An electrical method for centering telehandler rear wheels preferably includes an electronic control module (ECM), a rear steering cylinder, a pair of rear centering valves, a front steering cylinder, a steer mode valve, at least one steering position sensor, a steering control unit and a mode selection switch. The front and rear steering cylinders are connected to the steer mode valve. The steering control unit directs hydraulic fluid from a hydraulic pump to flow into the front and rear steering cylinders to turn the wheels. A 2W steering mode requires that the rear wheels be straight before going from a 4W steering mode into the 2W steering mode. The ECM monitors a position of the rear wheels through the at least one steering position sensor. If the wheels are not straight, the ECM will open a centering valve to straighten the rear wheels, before going into the 2W steering mode.

A lift device includes a base, an arm, a drive actuator, a tractive element, and a steering actuator. The arm has a base end coupled to the base and a tractive element end. The arm includes a steering actuator interface positioned along an exterior surface of the arm. The drive actuator is pivotally coupled to the tractive element end of the arm. The tractive element is coupled to the drive actuator. The steering actuator has a first end coupled to the steering actuator interface and an opposing second end coupled to the drive actuator. The arm includes a plate extending forward of the exterior surface of the arm and past the steering actuator.

A lift device includes a base having a first end and an opposing second end, a first arm pivotally coupled to the first end, a second arm pivotally coupled to the first end, a third arm pivotally coupled to the opposing second end, a fourth arm pivotally coupled to the opposing second end, and a leveling assembly. The leveling assembly includes a first actuator extending between the first arm and the first end, a second actuator extending between the second arm and the first end, a third actuator extending between the third arm and the opposing second end, a fourth actuator extending between the fourth arm and the opposing second end, and a controller configured to control the first actuator, the second actuator, the third actuator, and the fourth actuator to reconfigure the leveling assembly between (i) a shipping, transport, or storage mode and (ii) an operational mode.

A lift device includes a chassis, a first actuator coupled to the chassis, a second actuator coupled to the chassis, a third actuator coupled to the chassis, a fourth actuator coupled to the chassis, and a fluid circuit. The fluid circuit is configured to facilitate selectively fluidly coupling the first actuator, the second actuator, the third actuator, and the fourth actuator in at least four different configurations where, in each of the at least four different configurations, two of the first actuator, the second actuator, the third actuator, and the fourth actuator are fluidly coupled together while the other two of the first actuator, the second actuator, the third actuator, and the fourth actuator are fluidly decoupled.

Automatic steering and four-wheel steering are configured on an agricultural machine so that when automatic steering is enabled, a control system selectively activates and deactivates four-wheel steering depending on sensed turning or non-turning states of the machine. When automatic steering is enabled, the machine can automatically steer, such as according to a prescription map. In straightaway paths, corresponding to non-turning states, the control system can activate two-wheel steering. However, in the headlands of fields, corresponding to turning states, the control system can activate four-wheel steering. Such turning states can be determined based on the machines location on the map. Alternatively, such turning states can be determined based on sensed turning of the wheels. When an operator takes control of steering, such as by turning the steering wheel, automatic steering can disable, and the control system can activate four-wheel steering, to provide an optimum state for turning in the headlands of fields.

A method for steering the wheel assemblies of a gantry crane, including the steps of beginning the steering of at least one wheel assembly in the desired direction; and setting the angular position of a moveable pointer indicating a theoretical position of the wheel assembly which is consistent with said desired direction. The following steps are also included: setting an increment value of the moveable pointer in a direction consistent with respect to the steering movement of the wheel assembly; calculating the angular difference between the angular position of the moveable pointer and the current position of the wheel assembly; andincreasing the increment value of the moveable pointer if the difference shows a decrease, or decreasing the increment value of the moveable pointer if the difference shows an increase.