SEWING MACHINE WITH KNIFE

摘要

PROBLEM TO BE SOLVED: To make it possible to engage and disengage the retraction motion of a movable knife which occurs before a needle location position with simple constitution in order to cut the return end edge of the sewing fabric. SOLUTION: The movable knife 42 for cutting the fabric between itself and the stationary knife 43 by retracting to the front position of a throat plate 3 is mounted at one end of a knife shaft 41. A transmission lever 6 is loosely fitted to the intermediate part of this knife shaft 41 and a transmission ring 5 is fitted movably in the longitudinal direction of the shaft in proximity to this transmission lever 6. The opposite part of the transmission ring 5 and the transmission lever 6 is provided with a clutch means which is engaged and disengaged by attachment and detachment of both. The transmission lever 6 is connected via a link member 9 to an oscillation shaft which is oscillated around the axis by the transmission from a sewing machine spindle. The constitution that the transmission lever 6 is oscillated by the transmission from the oscillation shaft is adopted. This oscillation is transmitted via the transmission ring 5 to the knife shaft 41 only at the time of engagement of the clutch means, by which the movable knife 42 is actuated.