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The paper shows a possibility of the tuning mechanical system by means of two pneumatic springs in a differential configuration connected with a throttle valve. The springs are inserted into the lead mechanism and connected to its parts, and to its supporting platform. The vibrations, transferred from the kinematic excitation of the base, are intended to be minimized. The vibration isolation by means of pneumatic springs is available in many technical systems, e.g. in supports of heavy machinery as well as in systems characterized by the human interaction, such as driver seats, ambulance couchettes, etc. The pneumatic springs provide the option of adaption of the stiffness, and herewith the adaption of the natural frequency of the system according to the exciting frequency. In cases of application of the object vibration isolation, they can change the load characteristics in a relative large range. In the studied case of the differential spring configuration, the springs are connected with an air pipe to the throttle valve. The air being exchanged during the motion period comes through the valve, the cross-section of which determines the time delay of the pneumatic sub-system thus creating a hysteresis of load characteristic of the spring support. This brings an additional, controllable damping to such a system that is profitable in most vibration isolation cases.

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Chainsaws are devices that exhibit intense dynamic effects. Their duty cycle can be divided into several stages. In particular: start-up, operational run and run-down. During each stage the engine unit is connected to or disconnected from the working part through centrifugal clutch. When driven by internal combustion engine, the unfavourable vibrations occur at the handles due to unevenness of its run. Chainsaw manufacturers pay special attention to emergency braking in critical situations. Time necessary for chain to stop from encountering the first emergency trigger is taken as a measure of effectiveness of the breaking system. To assess specific chainsaw systems, it is necessary to create detailed computational dynamic model.