Patent ID: 6112612
Filing Date: 2000-09-05
Classification: B66F,G05G,Y10T

Abstract:
In a powered industrial lift truck having a stand up operator's compartment designed to orient the operator relative to the direction of travel for ergonomical use of different muscle groups of the operator's body, a first muscle group comprising those that are capable of imparting a rolling motion in a right to left manner relative to the direction the operator is facing to the operator's arm and hand in a first ""X"" direction of the stand up operator's compartment corresponding to the direction of travel and a second muscle group comprising those that are capable of imparting to the operator's arm and shoulder a push or pull motion in a second ""Y"" direction corresponding to the direction of the stand up operator's compartment that the operator is facing, the improvement comprising:powered means for propelling the powered industrial lift truck in either the forward or reverse directions at variable speeds;a mast mounted on the powered industrial lift truck having a lifting and lowering capability for a load carried by the mast;a multi function single lever operator hand control in the operator's compartment having a neutral position and two directions of motion therefrom comprising;a first pivot axis perpendicular to the ""X"" direction of operator's compartment about which said single lever operator hand control pivots using the first muscle group;a second pivot axis perpendicular to the ""Y"" direction of the stand up operator's compartment about which said single lever operator hand control pivots using said second muscle group;and control means responsive to displacement of said single lever operator hand control in either the ""X"" or ""Y"" directions from the neutral position against an ergonomic reaction force acting in the ""X"" direction which is substantially lighter than an ergonomic reaction force acting in the ""Y"" direction such that the operator's first muscle group is ergonomically coordinated to the lighter reaction force while the second muscle group is ergonomically coordinated to the larger reaction force in the ""Y"" direction whereby the operator can sustain longer periods of operation minimizing operator fatigue.