Patent ID: 6226582
Filing Date: 2001-05-01
Classification: B66F

Abstract:
A control system for an electric lift truck, the electric lift truck including a first electric motor for truck propulsion and a second electric motor connected to a hydraulic pump for supplying pressurized hydraulic fluid through a hydraulic circuit to a hydraulic lift mechanism, comprising:an interface for providing an integrated drive and hydraulic control system to permit an operator to control the propulsion of the electric lift truck and a plurality of functions of the hydraulic lift mechanism, the interface generating a plurality of electronic control signals in response to inputs through the interface by the operator;an electronic controller connected to the interface and the first and second electric motors for receiving the electronic control signals from the interface, and controlling a speed and a direction of revolution of the first electric motor, and a speed of revolution of the second electric motor in direct relation to the electronic control signals so that hydraulic functions are controlled by direct control of the second motor as well as incremental opening of control valves in response to the electronic control signals.