The universal motor powers an electro-pneumatic, low-vibration hammer mechanism which in turn is energised by an enclosed, pressurised and elastic air-cushion which ensures that the impact force remains constant. Light rotary hammers owe their low-vibration and noise reduced running to a flywheel transducer and a slipper piston. Medium and heavy rotary hammers utilise a conventional crank drive. Light rotary hammers of the latest generation are equipped with electro-mechanical striking mechanisms. In general, rotary hammers are used in their combined rotation/hammer function. Rotation can be switched off for slot-cutting or chiseling applications, or it is switched off automatically by the special shape of the chisel shank. This is called rotation stop.
The hammer mechanism can be turned off for the rotation-only mode which is required for drilling in steel, wood or plastic. This is called hammer stop.