On a running rail mobile crane trolley with a running gear three-wheeled

摘要

The crab has three travel wheels arranged in a triangular pattern, one of them being driven. Two sheels can be mounted coaxially, running on opposite lower flanges of the travel rail, and the third apart from them, running on one of the flanges, and driven by the travel motor. The wheels can be in the form of cylindrical rollers, running near the rail centre independent of its width, with guide members running against the edges of the flanges or the central web of the rail, and adjustable for width. The wheels and/or guides can be of plastic, and the crab hois drum can be so mounted below the rail that their two centre lines coincide.