TODAY’S PATENT- POWER TRANSMISSION DEVICE FOR A POWER-OPERATED LAWN MOWER
Today’s patent was invented by Masayuki Takeuchi, Kenji Nakamura, and Masahiro Handa on July 22, 1980, bearing patent no. US4213288A.
The present invention relates to a lawnmower, in which the cutting blade thereof is driven by an internal combustion engine and electronic motor or like other prime movers. It provides a power transmission device for such lawn moving device, which is simple in construction and which is capable of instantaneously stopping the blade operation as soon as the operator removes his hands from the handle grip, while the prime mover continues its rotation. In this device, a driving pulley is respectively fitted fixedly and rotatably on a power output shaft of a prime mover like an internal combustion engine. An electric motor and another driven pulley are rotatably fitted on a separate shaft disposed of in parallel with the output shaft.
There is a cutting blade is fastened to the first-mentioned driven pulley rotatably fitted on the output shaft as an integral part thereof. A first drive belt is loosely extended between the driving pulley and the second mentioned driven pulley belt is tightly extended between the first and second mentioned driven pulleys. There is one tension pulley that is further provided on a swingable supporting arm to impart tension to the loosely extended belt. When the cutting blade is to be rotated for lawn mowing and a brake applying implement is provided on one part of the swingable supporting arm to apply frictional braking force to the second-mentioned driven pulley when the cutting blade is to be stopped.