Battery fed plural motor control system for an industrial truck

Claim 1

AN INDUSTRIAL TRUCK COMPRISING, AN ELECTRIC TRACTION MOTOR FOR DRIVING SAID TRUCK, TWO BATTERIES CONNECTED IN SERIES AND MOUNTED ON SAID TRUCK FOR SUPPLYING ELECTRIC POWER TO SAID ELECTRIC TRACTION MOTOR, MOVABLE CONTROLLER MEANS, MEANS OPERATIVE BY INITIAL MOVEMENT OF SAID CONTROLLER MEANS IN ONE DIRECTION TO CONNECT ONE OF SAID BATTERIES ACROSS SAID TRACTION MOTOR AND ON A SUCCESSIVE OPERATION OF SAID CONTROLLER MEANS TO CONNECT THE OTHER OF SAID BATTERIES ACROSS SAID TRACTION MOTOR WHILE THE TWO BATTERIES REMAIN CONNECTED TO SERIES, WHEREBY A DIFFERENT BATTERY IS USED FOR LOW VOLTAGE, LOW SPEED OPERATION OF THE TRACTION MOTOR ON SUCCESSIVE OPERATIONS OF SAID CONTROLLER MEANS TO PREVENT SUBSTANTIAL UNEQUAL DISCHARGE OF SAID BATTERIES AND AT THE SAME TIME THE SUM OF THE VOLTAGES OF THE TWO BATTERIES IS AVAILABLE FOR OPERATION OF OTHER ELECTRICALLY OPERATED MEANS ON SAID TRUCK WHEN ONLY ONE BATTERY IS CONNECTED ACROSS THE TRACTION MOTOR, AND MEANS OPERATIVE BY CONTINUED FURTHER MOVEMENT OF SAID CONTROLLER MEANS IN SAID ONE DIRECTION TO CONNECT BOTH BATTERIES IN SERIES ACROSS SAID TRACTION MOTOR TO PROVIDE HIGH VOLTAGE, HIGH SPEED OPERATION OF SAID TRACTION MOTOR.