Anordning vid gaffeltruck

摘要

Device at fork truck where in a telescopically extendable mast in the outermost or uppermost mast section is arranged a movement journaling of movement of the forks over the major part of the height of the uppermost mast section, and where lifting movements are achieved hydraulically by means of one or several hydraulic pistons (4) for the lifting of the mast sections and one or several other hydraulic pistons (3) for the lifting of the forks (8) in relation to the uppermost mast section (5). In the feed conduits to the hydraulic cylinders proportional valves 1, 2 are arranged in order to, at the transition shift between low lift movement and high lift movement and vice versa successively control the oil flow to and from the cylinders of the different systems respectively so that an unnoticeable transition and constant speed is obtained.