Lift truck with a detachable mast assembly, and a propelling and elevating control system

Claim 2

IN A WHEELED LIFT TRUCK, A FRAME INCLUDING A PAIR OF FORWARDLY PROJECTING LATERALLY SPACED FRONT WHEEL SUPPORTS, A VERTICALLY MOVABLE LIFT PLATE, AN UPRIGHT MAST SERVING AS A GUIDE FOR A VERTICALLY MOVABLE LIFT PLATE, AN HYDRAULIC CYLINDER WITH INDENTED PORTIONS CARRIED BY THE MAST AS A UNIT THEREWITH AND HAVING A PISTON ADAPTED TO RAISE AND LOWER THE LIFT PLATE, SAID MAST AND CYLINDER BEING LOCATED BETWEEN SAID FRONT WHEEL SUPPORTS, INDIVIDUAL FRONT WHEEL AXLES SUPPORTED AND ENGAGEABLE WITH SAID INDENTED PORTIONS DETACHABLY IN SAID SUPPORTS, SAID AXLES HAVING INNER ENDS PIVOTALLY SUPPORTING SAID MAST AND CYLINDER UNIT, AND MEANS STABILIZING SAID MAST.

Claim 3

IN A WHEELED LIFT TRUCK HAVING A FRAME AND INCLUDING A SUPPORT FOR FRONT WHEELS AND A SUPPORT FOR A STEERABLE REAR WHEEL, AN UPRIGHT MAST SERVING AS A GUIDE FOR A VERTICALLY MOVABLE LIFT PLATE, A VERTICALLY MOVABLE LIFT PLATE, AN HYDRAULIC CYLINDER HAVING A PISTON ADAPTED TO RAISE AND LOWER THE LIFT PLATE AND SECURED AS A UNIT TO THE MAST, MEANS DETACHABLY SECURING SAID UNIT TO THE FRAME OF THE VEHICLE FOR PIVOTAL MOVEMENT TO A SELECTED POSITION RELATIVE TO A VERTICAL PLANE, MEANS FOR STEERING THE REAR WHEEL OF THE TRUCK, HYDRAULIC MEANS FOR DRIVING THE REAR WHEEL IN A FORWARD OR REVERSE DIRECTION AND INCLUDING A HYDRAULIC MOTOR, FIRST VALVE MEANS NORMALLY IN A NEUTRAL POSITION DISABLING THE DELIVERY OF FLUID UNDER PRESSURE TO SAID MOTOR AND ADAPTED WHEN DISPLACED FROM NEUTRAL POSITION TO A RELEASED POSITION TO ENABLE FLUID UNDER PRESSURE TO BE DELIVERED TO SAID MOTOR, SECOND VALVE MEANS IN SERIES WITH SAID FIRST VALVE MEANS TO CONTROL THE RATE OF FLUID BEING DELIVERED TO SAID HYDRAULIC MOTOR AND A TWO POSITION PEDAL NORMALLY IN AN IDLE POSITION EFFECTIVE TO HOLD SAID FIRST VALVE MEANS IN NEUTRAL POSITION AND ADAPTED WHEN HELD BY THE OPERATOR IN A RELEASED POSITION TO PERMIT SAID FIRST VALVE MEANS TO BE DISPLACED AS AFORESAID, AND THIRD VALVE MEANS IN SERIES WITH SAID FIRST VALVE MEANS, SAID THIRD VALVE MEANS OPERABLE TO A POSITION FOR DIRECTING FLUID TO SAID HYDRAULIC MOTOR AND FOR BLOCKING FLUID UNDER PRESSURE TO SAID PISTON FOR PREVENTING THE PISTON FROM BEING RAISED IF THE TRUCK IS IN MOTION.

Claim 4

IN A WHEELED LIFT TRUCK HAVING A FRAME AND INCLUDING A SUPPORT FOR FRONT WHEELS AND A SUPPORT FOR A STEERABLE REAR WHEEL, AN UPRIGHT MAST SERVING AS A GUIDE FOR A VERTICALLY MOVABLE LIFT PLATE, A VERTICALLY MOVABLE LIFT PLATE, AN HYDRAULIC CYLINDER HAVING A PISTON ADAPTED TO RAISE AND LOWER THE LIFT PLATE AND SECURED AS A UNIT TO THE MAST, MEANS DETACHABLY SECURING SAID UNIT TO THE FRAME OF THE VEHICLE FOR PIVOTAL MOVEMENT TO A SELECTED POSITION RELATIVE TO A VERTICAL PLANE, MEANS FOR STEERING THE REAR WHEEL OF THE TRUCK, HYDRAULIC MEANS FOR DRIVING THE REAR WHEEL IN A FORWARD OR REVERSE DIRECTION AND INCLUDING A HYDRAULIC MOTOR, FIRST VALVE MEANS NORMALLY IN A NEUTRAL POSITION DISABLING THE DELIVERY OF FLUID UNDER PRESSURE TO SAID MOTOR AND ADAPTED WHEN DISPLACED FROM NEUTRAL POSITION TO A RELEASED POSITION TO ENABLE FLUID UNDER PRESSURE TO BE DELIVERED TO SAID MOTOR, SECOND VALVE MEANS IN SERIES WITH SAID FIRST VALVE MEANS TO CONTROL THE RATE OF FLUID BEING DELIVERED TO SAID HYDRAULIC MOTOR AND A TWO POSITION PEDAL NORMALLY IN AN IDLE POSITION EFFECTIVE TO HOLD SAID FIRST VALVE MEANS IN NEUTRAL POSITION AND ADAPTED WHEN HELD BY THE OPERATOR IN A RELEASED POSITION TO PERMIT SAID FIRST VALVE MEANS TO BE DISPLACED AS AFORESAID, AND THIRD VALVE MEANS IN SERIES WITH SAID FIRST VALVE MEANS, SAID THIRD VALVE MEANS OPERABLE TO A POSITION FOR DIRECTING FLUID TO SAID HYDRAULIC MOTOR AND FOR BLOCKING FLUID UNDER PRESSURE TO SAID PISTON FOR PREVENTING THE PISTON FROM BEING RAISED IF THE TRUCK IS IN MOTION.