Abstract: A scissors lift apparatus has three scissor units for supporting heavy loads. A central scissor unit has its arms located inwardly of the immediately lower and upper scissor units, and folds into the upper and lower scissor units for storage within a chamber in a mobiled chassis. The scissor arms of the upper and lower scissor units includes rectangular box beams with a greater vertical than horizontal dimension. Hydraulic cylinders are located within and coupled to the opposite two arms of the center scissor unit to expand and collapse the same. The mobile chassis has front steering wheels mounted with hydraulic powered-caster-type wheel drive and steering apparatus. The steering king pin is laterally offset from the vertical plane through the center of wheel. A dual fail safe braking unit on the trailing wheels has an applied hydraulic cylinder unit including a floating cylinder with a single spring applied piston and rod which is supported in a fixed journal and connected to one wheel.

Abstract: A telescopic boom and lift apparatus positions a vertical support and platform and includes a telescopic boom unit and a rigid mechanical lift linkage to pivot the boom unit with automatic leveling of the support. The telescopic boom unit is pivoted to a base, with a motor unit coupled to extend and retract the boom unit. A rigid linkage unit is pivotally interconnected to the base and the tip boom of the boom unit. The linkage unit is constructed and arranged to support the boom unit in the retracted, collapsed position and to exert a lifting and pivot force on the boom unit in response to extension of the tip boom. Parallelogram linkages on the boom unit and lift unit are coupled to a pivot unit at the tip boom and maintains a precise orientation of the vertical support and platform. The lift arm unit includes parallel rigid arms which are laterally spaced such that the boom unit collapses into the lift unit to form a compact assembly.

Abstract: An improved work platform suitable for mounting on a vehicle mounted telescoping boom. The work platform includes a fixed platform section mounted on the tip of the boom in conjunction with a leveling mechanism. Two movable side platform sections are pivotally fastened at one of their ends to the fixed platform section for independent movement on either side of a centerline. The side platform sections may be moved apart in a scissors-like motion so that the platform may be maneuvered to straddle the object being worked on. Bumpers and troughs are provided along the inner edge of the side platform sections to protect the object being worked on and to prevent articles from rolling off the platform. When the side panel sections are moved into abutment to use the platform as a conventional unitary platform, a hinged flap on one of the side platform sections covers the abutting edges of the side platform sections, the bumpers and the troughs.