Abstract
This is the report on the outline of the trial construction of "the hanger of chain saw for anti-vibration", which is an equipment to reduce the transmission of vibration to the hand-arm system. The hanger consists of Shoiko-hanger, hanging arm having coilled springs, and clamping device. In the cutting operation, the worker carries the Shoiko on his back and hangs a chain saw with the hanging arm, fixing the chain saw at the top of the arm with the clamping device, and then can operate a chain saw with light touch (see Photo. 2). With this method we thought that the worker supported the weight of a chain saw with his body by the hanger, reducing the load of his hand-arm, and therefore, was reduced the transmission of the vibration to the hand-arm system. Considering of the operational performance in the forest, the type of the hangers were improved as shown from Photo. 1 to Photo. 5.
Examining the characteristics of the vibration transmission and the physiological change (HR and EMG) of workers in the operating, we concluded that this hanger could efficiently use in the bucking operations on the yard or the forest road but could not use for the present in the felling operations in the forest. In the future further experiments will be made to develop the hanger having more effective anti-vibartion ability and operational performance.
