Patent ID: 7121384
Filing Date: 2006-10-17
Classification: B21C,B66F

Abstract:
1. A two-or multi-stage truck mast for a truck, wherein said two- or multi-stage truck mast is either fixedly or tiltably mounted on a body and which comprises a first pair of substantially vertical beams, connected to each other with at least one substantially horizontal beam, said first pair of vertical beams and said at least one substantially horizontal beam and cylinder liners forming a fixed mast assembly, the vicinity of said assembly being provided with at least one second pair of substantially co-directional vertical beams that are connected to each other with at least one second substantially horizontal beam, wherein said at least one second pair of substantially co-directional vertical beams and said at least one second substantially horizontal beam forming a lift carrier adapted to move vertically relative to the fixed mast assembly under the propulsion of pistons in hydraulic cylinders, the drive and power being transmitted directly or over chains or cables to the lift carrier, the first pair of substantially vertical beams and cylinder liners of said fixed mast assembly providing an integrated structure, wherein the cylinder liners are constituted by channels integrated inside the first pair of vertical beams, which integrated structure has its cross-sectional centre of mass located at the centre of the corresponding cylinder liner or in the inimediate vicinity thereof, such that the integrated structure is capable of being manufactured by hot extrusion or cold drawing, wherein the integrated structure comprises: a first flange, which comprises mainly parallel surfaces, lying in a plane substantially transverse to an operating direction of the truck, an inner surface of said first flange being a bearing surface of a rolling contact bearing and an outer surface or an adjacent outer surface of the integrated structure being a support surface, and at least one second flange for placing the centre of mass substantially at the centre of the corresponding cylinder liner.