| 摘要 |
An overlock sewing machine comprises switching knob 64 operating an interlocking arm comprising arm (62b, figure 5) for releasing and returning a slide 6 to move slide pipes of a pneumatic looper threader to and from a threading position. Lever portions (62d, 62c) engage limiting arm pin (19b, figure 2) to cause limited rotation via shaft (16) of arm (20) which engages pin (27) to move it and associated main shaft 24 into or away from engagement with locking disc 29 of the main drive shaft 28. A slide member slot has a larger opening at one end. The end of the shaft 24 nearest the slide member has a small diameter which can be accommodated in the bulk of the slot and a larger diameter portion which can be accommodated in the larger opening. The sewing machine can be switched from a sewing to a threading position and back again by respective single actions of the same operating knob 64. The arm (20) comprises a bi-polar spring bias arrangement. A switch may cut power when the threading position is selected, and indication member 30 may be visible to the operator when the sewing position is selected. |
