Patent ID: 6158602
Filing Date: 2000-12-12
Classification: B60F,B61D,B66C

Abstract:
A method for handling objects comprising the steps of:providing a gantry crane having a frame, a lifting apparatus mounted to the frame for lifting an object; a plurality of wheel trucks mounted to the frame, a plurality of roadwheels, each of said roadwheels having a respective resilient tire supporting the gantry crane on an operating surface and, each of said trucks having at least one of said roadwheels mounted thereto, and at least one railwheel mounted to one of said trucks;providing a rail fixed relative to the operating surface;positioning the gantry crane on the road surface over the object adjacent the rail, so that the railwheel is vertically spaced above the rail;lifting the object; anddeflecting the tire in a non-deflated manner as a result of a load from lifting the object, thereby moving the railwheel downwardly to contact the rail.