Abstract: 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.

Abstract: An aerial work apparatus comprising a mobile chassis having a longitudinal centerline, a lift mechanism such as a scissors lift having a lower end connected to the chassis and an upper end which supports a work platform. The work platform has a longitudinal centerline which is laterally spaced from and parallel to the longitudinal centerline of the chassis such that the platform is laterally offset relative to the chassis and lift mechanism for substantially stabilizing the apparatus when handling heavy loads positioned at one side of the platform.

Abstract: An aerial work platform and guardrail system having a deck which may include a deck frame; vertically extending guardrail supports affixed to the deck or deck frame; and guardrail sections at the periphery of the deck. The sections have legs receivable in the guardrail supports with spaced upper and lower guides affixed to the legs, the guides being receivable in said guardrail supports and having surfaces for engaging inner surfaces of the guardrail supports. Retainers retain the lower guides in the guardrail supports whereby the guardrail sections may be individually lifted from a lower operative position to an upper pivot position at which the sections are retained in the supports by engagement of lower guides with the retainers and may be pivoted about the lower guides to a horizontal position for storage.