US Patent 10434682 Quick chain tensioning system

A quick tensioning system applicable to handheld chainsaws is provided wherein, during chain re-tensioning, the chain guiding bar remains firmly anchored to the bar holder and guiding means are provided to retract the motorized driving sprocket versus said guiding bar. The system includes a guide interposed between a stationary bar holding body and a motor body. This allows a linear or a rotation relative movement between the sliding driving sprocket and the stationary guiding bar. A drive is provided by means of a screw that an operator can easily operate via a knob conveniently mounted nearby the chainsaw handle.