Engine with a rotary-speed control apparatus and an emergency halt apparatus

摘要

An engine has a load detector, or more specifically a threshold load comparator, and also detectors for sensing any abnormality of various factors influencing the normal engine operation. When no abnormality is sensed, the engine is made to operate automatically at a low speed level when the engine load is below the threshold value, and at a high speed level when the load is beyond such value. When any abnormality is sensed, then the engine is emergently halted in a fail-safe manner, thus any damaging disorder in controling circuitry for effecting such emergent halting leads in itself to emergent halting of the engine as well.