Abstract: Pump assembly for the lift cylinder of a hand fork-lift truck includes a piston pump activated by a bar of a hand fork-lift truck and has a piston chamber and an annulus collector. A three stage control valve connects the lift cylinder with a tank in the lowered setting and connects the piston chamber with the tank in a neutral setting and in a pump setting, connects the piston chamber with the lift cylinder through a first check-valve, with the tank through a second check-valve, a third check-valve between the piston chamber and the annulus collector open to the piston chamber, and a reversing valve between the piston chamber and the annulus collector.

Abstract: A braking system for battery-powered industrial trucks, comprising a three-phase driving motor which drives a driving wheel, a first braking device associated with the driving wheel, a brake pedal with which a braking signal generator is associated to generate an electric braking signal corresponding to a first desired braking force in response to the excursion of the brake pedal, a control device for the driving motor, a first conversion unit in the control device which converts said braking signal into a desired torque for the driving motor, a second conversion unit in the control device which converts the actual torque of the driving motor into an actual braking force, a comparator device in a braking control in which the first desired braking force is compared to the actual braking force to form a second desired braking force for the second braking device.

Abstract: Hydraulic lifting device for battery-operated industrial trucks, with at least one hydraulic lifting cylinder, a hydraulic pump working as a pump in the load lifting operation mode, supplying the lifting cylinder with pressure medium and working as a motor in the operation mode of lowering the load, driven by the pressure medium that is displaced by the lifting cylinder, an electric machine coupled to the hydraulic pump, working as an electric motor in the load lifting mode and working as a generator in the mode of lowering the load, a rotation speed control device for the electric machine, the electric machine being controllable in its speed by the rotation speed control device, depending upon the actuation of a set-point transmitter, a lifting valve arrangement in a lifting branch leading to the lifting cylinder, a lowering branch between the lifting cylinder and a connection between a check valve and an entry of the hydraulic pump, a volume flow delimiter in the lowering branch, a bypass valve arrangement

Abstract: Abstract of the Disclosure Driving system for a machine, in particular an industrial truck with a combustion engine, a two-branch gear transmission whose first shaft is coupled to the combustion engine, whose second shaft is coupled to a change-over transmission, whose outlet acts on the driven wheels of the industrial truck via a collecting transmission, an electric transmission of which a first electric machine cooperates therewith, with respect to the torque, by means of the two-branch gear transmission, and a second electric machine is coupled via at least one collecting transmission to the driven wheels, the two-branch gear transmission producing a constant torque ratio between the first electric machine and at least the first and second shaft and an electrical circuit arrangement electrically coupling the electric machines and being connected to an electric accumulator, two mechanical hydraulic converters of which one is coupled to the first or second shaft of the two-branch gear transmission and the se

Abstract: Abstract of the Disclosure Driving system for a machine, in particular an industrial truck with a combustion engine, a two-branch gear transmission whose first shaft is coupled to the combustion engine, whose second shaft is coupled to a change-over transmission, whose outlet acts on the driven wheels of the industrial truck via a collecting transmission, an electric transmission of which a first electric machine cooperates therewith, with respect to the torque, by means of the two-branch gear transmission, and a second electric machine is coupled via at least one collecting transmission to the driven wheels, the two-branch gear transmission producing a constant torque ratio between the first electric machine and at least the first and second shaft and an electrical circuit arrangement electrically coupling the electric machines and being connected to an electric accumulator, two mechanical hydraulic converters of which one is coupled to the first or second shaft of the two-branch gear transmission and the se

Abstract: Driving system for a machine, in particular an industrial truck with a combustion engine, a two-branch gear transmission whose first shaft is coupled to the combustion engine, whose second shaft is coupled to a change-over transmission, whose outlet acts on the driven wheels of the industrial truck via a collecting transmission, an electric transmission of which a first electric machine cooperates therewith, with respect to the torque, by means of the two-branch gear transmission, and a second electric machine is coupled via at least one collecting transmission to the driven wheels, the two-branch gear transmission producing a constant torque ratio between the first electric machine and at least the first and second shaft and an electrical circuit arrangement electrically coupling the electric machines and being connected to an electric accumulator, two mechanical hydraulic converters of which one is coupled to the first or second shaft of the two-branch gear transmission and the second to the electric transm

Abstract: Hydraulic lifting device for battery-operated industrial trucks, with at least one hydraulic lifting cylinder, a hydraulic pump working as a pump in the load lifting operation mode, supplying the lifting cylinder with pressure medium and working as a motor in the operation mode of lowering the load, driven by the pressure medium that is displaced by the lifting cylinder, an electric machine coupled to the hydraulic pump, working as an electric motor in the load lifting mode and working as a generator in the mode of lowering the load, a rotation speed control device for the electric machine, the electric machine being controllable in its speed by the rotation speed control device, depending upon the actuation of a set-point transmitter, a lifting valve arrangement in a lifting branch leading to the lifting cylinder, a lowering branch between the lifting cylinder and a connection between a check valve and an entry of the hydraulic pump, a volume flow delimiter in the lowering branch, a bypass valve arrangement

Abstract: Pump assembly for the lift cylinder of a hand fork-lift truck includes a piston pump activated by a bar of a hand fork-lift truck and has a piston chamber and an annulus collector. A three stage control valve connects the lift cylinder with a tank in the lowered setting and connects the piston chamber with the tank in a neutral setting and in a pump setting, connects the piston chamber with the lift cylinder through a first check-valve, with the tank through a second check-valve, a third check-valve between the piston chamber and the annulus collector open to the piston chamber, and a reversing valve between the piston chamber and the annulus collector.

Abstract: A braking system for battery-powered industrial trucks, comprising a three-phase driving motor which drives a driving wheel, a first braking device associated with the driving wheel, a brake pedal with which a braking signal generator is associated to generate an electric braking signal corresponding to a first desired braking force in response to the excursion of the brake pedal, a control device for the driving motor, a first conversion unit in the control device which converts said braking signal into a desired torque for the driving motor, a second conversion unit in the control device which converts the actual torque of the driving motor into an actual braking force, a comparator device in a braking control in which the first desired braking force is compared to the actual braking force to form a second desired braking force for the second braking device.

Abstract: A method for influencing the torque on at least one driving wheel of an industrial truck for the purpose of driving and/or braking it wherein the torque of a driving motor for the industrial truck is reduced by means of a slip regulator at an appropriate amount depending on the slip by determining the slip between the driving wheel and the floor by making a comparison of the circumferential speed measured or calculated for the driving wheel and the vehicle travelling speed measured for the industrial truck, and comparing it to a set-point.

Abstract: A method for influencing the torque on at least one driving wheel of an industrial truck for the purpose of driving and/or braking it wherein the torque of a driving motor for the industrial truck is reduced by means of a slip regulator at an appropriate amount depending on the slip by determining the slip between the driving wheel and the floor by making a comparison of the circumferential speed measured or calculated for the driving wheel and the vehicle travelling speed measured for the industrial truck, and comparing it to a set-point.

Abstract: An apparatus for controlling a drive system for an industrial truck having an internal combustion engine and a hydrostatic transmission wherein the hydrostatic transmission has a pump the delivery volume of which is variable and at least one hydraulic engine acting on at least one wheel of the industrial truck, comprising a first controller for the speed of the industrial truck in which a desired speed value compares to a actual value arriving from a speed transducer, further in which a speed controller determines a corresponding desired motive force and in which the signal for the motive force and the actual speed is provided to a characteristics stage in which at least one characteristic is stored which assigns approximately optimal rpm values to power values of the internal combustion engine and presets a corresponding desired-value signal for the number of revolutions of the internal combustion engine, and a second controller underlying the first controller having a desired-value and actual-value comparat

Abstract: An industrial truck, particularly a fork-lift truck, wherein the front and rear wheels are supported on a vehicle frame and one of which is adapted to be driven, a load-receiving means which is adjustable at least in height by means of a power-exerting apparatus, and a safety device which detects a tilt of the industrial truck and is in an operative communication at least with an alarm signal emitter, whereby a load sensor is associated with at least one wheel and the safety device has a comparison device which provides a signal to the alarm signal emitter when one or more of the wheel loads measured fall below a preset value.

Abstract: An apparatus for controlling a drive system for an industrial truck having an internal combustion engine and a hydrostatic transmission wherein the hydrostatic transmission has a pump the delivery volume of which is variable and at least one hydraulic engine acting on at least one wheel of the industrial truck, comprising a first controller for the speed of the industrial truck in which a desired speed value compares to a actual value arriving from a speed transducer, further in which a speed controller determines a corresponding desired motive force and in which the signal for the motive force and the actual speed is provided to a characteristics stage in which at least one characteristic is stored which assigns approximately optimal rpm values to power values of the internal combustion engine and presets a corresponding desired-value signal for the number of revolutions of the internal combustion engine, and a second controller underlying the first controller having a desired-value and actual-value comparat

Abstract: A follower industrial truck including a drive motor, a handle lever having a first end which is linked to a steering shaft of the industrial truck to pivot about a horizontal axis, a handle lever head which is movably mounted with respect to the handle lever in a pull and push manner, a spring arrangement between the handle lever and the head, which biases the head in opposite directions towards a neutral position produces a path signal (Sist), the magnitude of the path signal (Sist) being approximately proportional to the extent of the deflection, a first controller which produces a first nomimal value (Isoll) for the current of the drive motor, and a further controller adapted to receive a comparison current value which is achieved by the comparison of the actual current value (Iist) of the drive motor and of the first nomimal value (Isoll) from the first controller in order to produce a setting current value for the drive motor.