Patent ID: 8770123
Filing Date: 2014-07-08
Classification: D05B

Abstract:
1. An overlock sewing machine comprising: an upper knife that is movable to a withdrawn position lower than a throat plate or a driving position higher than the withdrawn position, and that moves up and down from above a workpiece on the throat plate to cut the workpiece at the driving position; an upper knife driving unit that moves the upper knife up and down at the driving position; an interlocking switching unit that switches between an interlocking state in which the upper knife driving unit and the upper knife interlock with one another and a release state in which interlocking between the upper knife driving unit and the upper knife is released; an upper knife position switching unit that switches an installation position of the upper knife to the driving position or the withdrawn position; and an operating unit that simultaneously drives the interlocking switching unit and the upper knife position switching unit such that the interlocking switching unit is brought into the interlocking state in a case where the installation position of the upper knife is switched to the driving position by the upper knife position switching unit, and such that the interlocking switching unit is brought into the release state in a case where the installation position of the upper knife is switched to the withdrawn position by the upper knife position switching unit, wherein the operating unit includes: the upper knife driving unit includes: the upper knife position switching unit moves the second link section so as to move the upper knife from the driving position to the withdrawn position when the cam portion engages with the upper knife position switching unit, and so as to move the upper knife from the withdrawn position to the driving position when the cam portion gets out of the engagement, and when the interlocking switching unit is driven by the first link section, the interlocking switching unit moves the rod so as to detach the notch from the engaging portion to bring the interlocking switching unit into the release state, and so as to bring the notch to engage with the engaging portion to bring the interlocking switching unit into the interlocking state.