Vibration protection for an operator of a hand-held percussion machine

The present study shows that a passive system of vibration protection, which combines principles of vibration isolation and dynamic absorption, can be effectively used in hand-held percussion machines. The vibration isolator between the handle and the casing of the machine reduces the high-frequency components of acceleration perceived by an operator, whereas the lightly weighted tuned dynamic absorbers attached to the handle allow suppression of dominating harmonics of machine acceleration. Such a vibration attenuation system allows the use of relatively stiff isolators and significantly reduces hand-transmitted vibration without essential increasing the overall mass of a tool. Results of numerical simulations have been verified by experiment and these are presented in this paper.