Abstract: A scissors lift vehicle includes a chassis, a first pair of wheels disposed at one end of the chassis and a second pair of steering wheels disposed at an opposite end of the chassis. The wheels include a circular profile having a radius R. The scissors lift vehicle includes a track having an upper surface and a lower surface extending aft at a height less than R above the travel surface. A pivot connection is coupled to the aft plate at a height less than R above the travel surface. A scissors stack assembly includes a plurality of paired scissors linkages. Each scissors linkage of a first pair of scissors linkages is coupled to a respective pivot connection. Each scissors linkage of a second pair of scissors linkages includes a truck coupled to a distal end. The truck is configured to engage the upper surface of the track.

Abstract: A scissors lift vehicle includes a chassis, a first pair of wheels disposed at one end of the chassis and a second pair of steering wheels disposed at an opposite end of the chassis. The wheels include a circular profile having a radius R. The scissors lift vehicle includes a track having an upper surface and a lower surface extending aft at a height less than R above the travel surface. A pivot connection is coupled to the aft plate at a height less than R above the travel surface. A scissors stack assembly includes a plurality of paired scissors linkages. Each scissors linkage of a first pair of scissors linkages is coupled to a respective pivot connection. Each scissors linkage of a second pair of scissors linkages includes a truck coupled to a distal end. The truck is configured to engage the upper surface of the track.

Abstract: A method and system for a scissors lift vehicle are provided. The scissors lift vehicle includes a carriage including a plurality of independently steerable wheels configured to engage a travel surface, the wheels including an axis of rotation and a circular profile having a radius R, the wheels spaced apart in a fore/aft direction and in a right/left direction.

Abstract: A system and method of controlling a scissors lift vehicle are provided. The system includes a main computer including one or more processors and one or more memory devices communicatively coupled to the one or more processors, a steer controller configured to receive commands from the main computer to control a plurality of independently steerable wheel assemblies, each wheel assembly including a steer angle sensor, a steer angle actuator, and a drive motor, and a scissors lift controller configured to control a hydraulic piston assembly including a hydraulic fluid reservoir internal to a piston rod assembly. The system also includes a tilt sensor configured to determine an angle of incline the scissors lift vehicle, a variable-speed steer actuator configured to rotate a wheel assembly about the steer axis of rotation at a selectable rate, and a wheel including a respective drive axis of rotation.

Abstract: A system and method of operating a scissors lift assembly are provided. The system includes a hollow piston rod including an internal fluid reservoir, a cylinder body that is coaxial with and at least partially surrounding the hollow piston rod, and a fluid pump in flow communication with the reservoir through a suction channel extending from the internal fluid reservoir though a transfer tube to a suction port of the fluid pump. The transfer tube is coaxial with the piston, the piston rod, and the cylinder body and a discharge port of the fluid pump is in flow communication with an extension pressure chamber.

Abstract: A system and method of controlling a scissors lift vehicle are provided. The system includes a main computer including one or more processors and one or more memory devices communicatively coupled to the one or more processors, a steer controller configured to receive commands from the main computer to control a plurality of independently steerable wheel assemblies, each wheel assembly including a steer angle sensor, a steer angle actuator, and a drive motor, and a scissors lift controller configured to control a hydraulic piston assembly including a hydraulic fluid reservoir internal to a piston rod assembly. The system also includes a tilt sensor configured to determine an angle of incline the scissors lift vehicle, a variable-speed steer actuator configured to rotate a wheel assembly about the steer axis of rotation at a selectable rate, and a wheel including a respective drive axis of rotation.

Abstract: A system and method of controlling a scissors lift vehicle are provided. The scissors lift vehicle system includes a carriage including a plurality of independently steerable wheel assemblies configured to engage a travel surface. The plurality of independently steerable wheel assemblies, each steerable about a steer axis of rotation include one of the plurality of wheel assemblies being designated a master wheel and the remaining wheel assemblies being designated slave wheels. The wheel assemblies each include a variable-speed steer actuator configured to rotate a respective wheel assembly about the steer axis of rotation of that wheel assembly at a selectable rate. The wheel assemblies each also include a wheel including a respective drive axis of rotation and a variable-speed drive actuator configured to rotate that wheel about a respective steer axis of rotation at a selectable rate.

Abstract: A system and method of operating a scissors lift assembly are provided. The system includes a hollow piston rod including an internal fluid reservoir, a cylinder body that is coaxial with and at least partially surrounding the hollow piston rod, and a fluid pump in flow communication with the reservoir through a suction channel extending from the internal fluid reservoir though a transfer tube to a suction port of the fluid pump. The transfer tube is coaxial with the piston, the piston rod, and the cylinder body and a discharge port of the fluid pump is in flow communication with an extension pressure chamber.

Abstract: A system and method of controlling a scissors lift vehicle are provided. The scissors lift vehicle system includes a carriage including a plurality of independently steerable wheel assemblies configured to engage a travel surface. The plurality of independently steerable wheel assemblies, each steerable about a steer axis of rotation include one of the plurality of wheel assemblies being designated a master wheel and the remaining wheel assemblies being designated slave wheels. The wheel assemblies each include a variable-speed steer actuator configured to rotate a respective wheel assembly about the steer axis of rotation of that wheel assembly at a selectable rate. The wheel assemblies each also include a wheel including a respective drive axis of rotation and a variable-speed drive actuator configured to rotate that wheel about a respective steer axis of rotation at a selectable rate.

Abstract: A method and system for a scissors lift vehicle are provided. The scissors lift vehicle includes a carriage including a plurality of independently steerable wheels configured to engage a travel surface, the wheels including an axis of rotation and a circular profile having a radius R, the wheels spaced apart in a fore/aft direction and in a right/left direction.