Abstract: A fluid operated actuator includes a shaft and a housing. The shaft is at least partially mounted in the housing for relative rotation between the shaft and the housing. The shaft includes a substantially central bore in which a first piston is mounted. The shaft also includes a fluid inlet that is connectable to supply of pressurised fluid and a fluid outlet. A conduit is provided for the flow of fluid between the inlet and the outlet. One end of the housing includes a chamber in which there is mounted a valve assembly comprising a second piston and a valve arranged to selectively open or close an inlet to the chamber. Fluid exiting the outlet opens the valve and exerts a force on the second piston, causing movement thereof in a first direction.

Abstract: A drive mechanism for a rotating body having a rotatable shaft includes a clutch to selectively transmit torque input to the shaft, a brake to slow down rotation of the shaft upon disengagement of the clutch, and an actuator to engage and disengage the clutch and brake. The clutch and brake are each mounted on a mounting member which is movable with respect to the shaft in the axial direction thereof. The actuator includes an actuator member that is slidably mounted on the mounting member and an actuator to move the actuator member from a first position, in which the clutch is engaged and the brake is disengaged, and a second position, in which the clutch is disengaged and the brake is engaged.

Abstract: A method for measuring the height of the cutting table of an earth-processing implement or an agricultural implement, such as, for example, a combine harvester, relative to a surface of a ground having crops by means of an acoustic transducer arrangement. The method includes forming the sound signal emitted by the transducer arrangement by a pseudonoise signal covering a predetermined frequency band. Comparing the sound signal with the reflected signal. Mutually delaying the sound signal and the reflected signal until the comparison has reached its optimum. Whereafter, the delay represents a measurement of the distance to the surface of the ground.

Abstract: A method of determining the mass flow speed of a granular material through a channel by means of electromagnetic waves, preferably in the microwave area. According to the invention, either the attenuation or the phase-shift is measured or both the attenuation and the phase-shift and optionally also the reflection. Based on the knowledge of both the reflection and the absorption it is possible to determine the type of grains being involved because the proportion of these magnitudes is characteristic of the various types. When measuring especially oil-containing grains which are able to have an effect on the dielectricity constant, it is advantageous to measure the phase of the transmitted signal because the phase-shift is substantially proportional to the flow of such grains.