On the driving mechanism of the cutter barknife for a small-sized reaping machine with reference to its cutting graphs

Abstract

Three different types of driving mechanism of the cutter bar-knife, with which a small-sized reaping machine is to be reasonably equipped, have been studied with cutting graphs. The results obtained are as follows:
1) Skew-crank mechanism may be suitablle for knife drive, as far as the skew ratio e/L is small, being capable of driving a bar-knife without a hitch.
As the ratio is getting larger, however, the movement of the knife becomes unsmoothy, changing it into a quick return motion. A′ type shown in Fig. 1 may be best for the knife drive.
2) Oscillating slider-crank mechanism is mostly unsuitable for driveing the knife, it brings forth a wide variation of knife speed at reciprocation. B′ type, nearly equal to A′ one, may to some extent. be recommended.
3) Lever-crank mechanism is thought fit only when the extension line connecting between the both. ends of a lever passes the center of a crank wheel.