A method and an alignment system which auto-levels and/or auto-centers a loading platform to load and unload a wheeled stretcher to and from an emergency transport vehicle are disclosed. A controller of the alignment system receives a command to extend the loading platform from the emergency vehicle and extends the loading platform under power from the emergency transport vehicle. The controller recognizes an approaching wheeled stretcher, and aligns automatically the loading platform with a leading edge of the approaching wheeled stretcher to compensate automatically for any alignment issues between the loading platform and loading wheels of the wheeled stretcher.

A roof vehicle has a chassis, a plurality of motor-driven wheels coupled to the chassis, a man-basket coupled to the chassis, wherein the man-basket is moveable on a y-axis and is configured to lower to an elevation beneath that of the plurality of motor-driven wheels, a deck for transporting equipment, and a power supply. A method for assembling and installing a roof involves moving the roof vehicle to the desired location on the roof of a structure, lowering the man-basket at least partially beneath the surface roof, and performing work (e.g., welding) to secure the roof to the structure of the building.

A system for assembling roofing at ground level has an adjustable-length center frame separating a first assembly side from a second assembly side; a first cantilevered gantry on the first assembly side and a second cantilevered gantry on a second side, each cantilevered gantry moveable along the length of the center frame; a plurality of outrigger beams coupled to opposing ends of the center beam, each outrigger beam having a catwalk thereon; a first joist railing and a second joist railing on each assembly side, each joist railing configured to receive an end of an open web joist; and a base frame comprising a plurality of wheels. Once the roofing section has been assembled, hoisting the assembled roofing section to the top of a structure.

A system for assembling roofing at ground level has an adjustable-length center frame separating a first assembly side from a second assembly side; a first cantilevered gantry on the first assembly side and a second cantilevered gantry on a second side, each cantilevered gantry moveable along the length of the center frame; a plurality of outrigger beams coupled to opposing ends of the center beam, each outrigger beam having a catwalk thereon; a first joist railing and a second joist railing on each assembly side, each joist railing configured to receive an end of an open web joist; and a base frame comprising a plurality of wheels. Once the roofing section has been assembled, hoisting the assembled roofing section to the top of a structure.

A drive assembly is provided and includes a rotatable housing, a motor disposed within and to rotate with the housing, the motor including a drive element and first and second drive shafts, which are independently rotatably drivable by the drive element, a first drivable element coupled to the first drive shaft such that rotation thereof is transmitted to the first drivable element and configured to propel the housing in a first direction during first drive shaft rotation and a second drivable element coupled to the second drive shaft such that rotation thereof is transmitted to the second drivable element and configured to propel the motor in a second direction, which is transversely oriented relative to the first direction, relative to the housing during second drive shaft rotation.

A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The frame forms an undercarriage chassis which the tandem wheel assembly is positioned there under. The undercarriage chassis includes a rear wheel assembly, a front wheel assembly, and an extension assembly moving the front wheel assembly between trailing position and a self-propelled position where the rear wheel assembly and the front wheel assembly are positioned to equally support the undercarriage chassis.

A vehicle and a hydraulic propulsion system for the vehicle are provided with first and second motors diagonally arranged relative to one another on the vehicle, and third and fourth motors diagonally arranged relative to one another on the vehicle. First, second and third flow divider combiner assemblies are provided and are arranged in a closed fluid loop with the motors. A first port of each of the assemblies are fluidly connected to one another. The first assembly has a second port fluidly coupled to the first and second motors, and a third port fluidly coupled to the third and fourth motors. The second assembly has second and third ports fluidly coupled to the first and third motors, respectively. The third assembly has second and third ports fluidly coupled to the second and fourth motors, respectively. A method of controlling the hydraulic system is also provided.

A vehicle wheel positioning and steering apparatus particularly useful for aerial work platforms comprises a support chassis and chassis support legs pivotally connected to the chassis. Steerable wheel assemblies are operably connected at ends of the support legs and powered actuators are operably connected to the chassis and legs for pivotally moving the legs and wheel assemblies relative to the chassis between transport and working positions. Variable length linear wheel steering actuators comprise one link of four bar parallelogram steering linkages between the chassis and wheel assemblies and the support legs each comprise second bars of the four bar parallelogram steering linkages.

A method and an alignment system which auto-levels and/or auto-centers a loading platform (104) to load and unload a wheeled stretcher (106) to and from an emergency transport vehicle (100) are disclosed. A controller (114) of the alignment system receives a command to extend the loading platform from the emergency vehicle and extends the loading platform under power from the emergency transport vehicle. The controller recognizes an approaching wheeled stretcher, and aligns automatically the loading platform with a leading edge of the approaching wheeled stretcher to compensate automatically for any alignment issues between the loading platform and loading wheels (130) of the wheeled stretcher.

A trailer for towing by a power vehicle is provided and generally includes a frame, a tandem wheel assembly and an extension assembly. The frame forms an undercarriage chassis and the tandem wheel assembly is positioned under the undercarriage chassis. The tandem wheel assembly includes a front wheel assembly and a rear wheel assembly having a drive assembly. The extension assembly moves the front wheel assembly between trailing position and a self-propelled position.