Abstract: Method and apparatus for providing an indication of compaction in vibration compacting machines. A signal proportional to acceleration occuring when the working part of a vibrating compaction machine strikes soil is developed by means of an acceleration pick-up and is compared with a stepped sequence of potentials representative of preselected acceleration values. During consecutive observation intervals it is observed which of these potentials are exceeded and which are not exceeded by the maximum acceleration occuring in an observation interval. In one embodiment, a control signal is developed which provides an indication of the compaction. The control signal is used to change the preselected acceleration values dependent upon the degree of compaction. Another embodiment of the invention develops a signal which is used to change the distance between the preselected acceleration values independent of the control signal.

Abstract: The invention relates to a safety device in road rollers, which have a guide rod with a guide handle so that they can be guided by an operator walking in front of or behind the road roller, and which are driven by an engine through drive transmission means arranged to be disabled, said safety device comprising a sensor element, which extends substantially along the length of the guide handle and responds to the operator grasping the guide handle, and further comprising servo means controlled by the sensor element and adapted to disable the drive transmission means upon releasing of the guide handle.

Abstract: A soil compactor has (1) an apparatus preceding it to measure characteristics of the soil significant to the compaction operation, and/or (2) an apparatus following it to measure characteristics of the soil after compaction. The soil compactor has one or more controls over the compaction operation. The controls are operated in accordance with the measurement indications of said apparatus.

Abstract: To determine standardized values of noise levels of machines a sound recording and reproducing instrument is employed to record the sound emission from a sound source of the type to be investigated. The recording and reproducing instrument is used as a reference source to obtain measured values of sound level on a standard and on a freely selected measuring place under standard conditions. The difference of the two values is applied to the value of sound level measured for the machine to be investigated on the selected measuring place under said standard conditions to yield standardized values of sound level.