Patent ID: 7036478

Claim:
An engine operated machine system comprising: an engine; a hollow support rod connected at one end to said engine through a vibration insulator; a working instrument supported at the other end of said support rod; and a drive shaft disposed within said support rod and connected coaxially to one end of a crankshaft of said engine to drive said working instrument; said vibration insulator being disposed between a center of gravity of said engine and a center of vibration of said engine, wherein an auxiliary weight is mounted at the other end of the crankshaft and generates a centrifugal force in the same direction as an inertia force of a piston, when said piston reaches top and bottom dead centers, and further wherein a counterweight, for generating a centrifugal force balanced with the centrifugal force generated by said auxiliary weight, is mounted to the crankshaft between the piston and said auxiliary weight.