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 motion controller for a motor-driven transportation truck or trolley with a steering pole that can be swivelled about a horizontal axis attached to a steering shaft or a steering frame and is provided with means for setting the direction of motion and the speed, characterized in that the steering pole is equipped with a sensor means providing an output signal that depends not only on the magnitude of the force applied to the steering pole, but also on whether this force is a push or a pull, and that the system also comprises a feed back controller unit that sets and/or regulates the speed and the direction of rotation of the driving motor according to this output signal.

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.

Abstract: A hydraulic lift apparatus for a battery driven lift truck includes a hydraulic lift cylinder. A hydraulic pump operates as a pump in a load raising mode, so as to feed pressure fluid to the lift cylinder. The hydraulic pump operates as a motor in a load lowering mode. The hydraulic pump is driven by the pressure fluid displaced by the lift cylinder. A direct current machine is coupled to the hydraulic pump, so as to operate as an electric motor in the load raising mode and to operate as a generator in the load lowering mode. A useful brake circuit is energized by the direct current machine in the load lowering mode. A valve assembly is disposed in the pressure fluid path between the lift cylinder and the hydraulic pump. Control apparatus are provided for controlling the valve assembly and including speed regulating apparatus for varying the speed of the direct current machine. At least one secondary hydraulic consumer is adapted to be connected to a hydraulic pressure source via an associated control valve.

Abstract: A hydraulic lift device for battery operated industrial trucks comprising a hydraulic ram, a hydraulic machine operating as a pump in a load raising cycle and as a motor in a load lowering cycle, a separately excited DC machine operating as a motor in the load raising cycle and as a generator in the load lowering cycle, and energy recovering circuitry which is fed by the DC machine in the load lowering cycle. A load holding valve is disposed in the fluid path between the hydraulic ram and the hydraulic machine. Speed of the DC machine is set by a speed control. A separate field current control includes a desired value setting circuit for determining a desired value for the field current (I.sub.FSoll) from a predetermined relationship between the speed (n.sub.Ist) and the armature current (I.sub.ASoll). Power switches are associated with the field winding and the armature, and are actuated by the current control.

Abstract: A linear drive for use in air and space travel converts the rotational drive of an electromotor into a linear motion of a runner which is secured to at least one flexible coupling member. The flexible coupling member runs around at least one guide member at one end thereof, and around a drive wheel driven by the electric motor at the other end of the flexible coupling member. The rotating drive wheel and the guide member both change the movement direction of the flexible coupling member, whereby the runner can run back and forth between the drive wheel and the guide member.