Abstract: A cutting device for a sewing machine includes an upper-blade positioning device and a lower-blade positioning device. The upper-blade positioning device includes an upper blade upper blade fixed at a head portion of the upper-blade holder, and a spring and a restricting member sleeved on a body portion of the upper-blade holder. A restricting pin is engaged between an upper-blade drive member and the restricting member. A guide member includes a guide hole for insertion of a rod portion of the upper-blade drive member and is fixed to the base. The upper-blade drive member is inserted through a guide member of the base and moved by a connecting rod. The lower-blade positioning device includes a lower-blade holder, an adjustment member. A lower-blade shaft has one end fixed to the base and another end extended out of the base, rotating the adjustment member can adjust the position of the lower-blade holder.

Abstract: A presser foot having a shoe comprising a pair of mutually facing front portions (5a, 5b) and a pair of rear portions (6a, 6b) in alignment with the front portions (5a, 5b) and connected thereto by a pair of side rocker arms (7a, 7b). The side rocker arms (7a, 7b) are pivotably supported by swinging arms (10a, 10b) linked to a small bearing frame (2). A center rocking arm (15) mounted on the bearing frame (2) acts by a pair of laterally disposed pistons (17a, 17b) on the individual swinging arms (10a, 10b) in order to mutually balance the fulcra of the side rocker arms (7a, 7b). Operating at a longitudinal opening (29) defined between the front portions (5a, 5b) is a fixed knife (32) and a movable knife (33) which are adjustable independently of each other in their vertical positioning relative to the shoe (4).

Abstract: An adjusting device for a lower knife being disposed in a support of a sewing machine and including a sleeve fitted in the support and having a pair of slots, a bolt rotatably received in the sleeve and having one end extended outward of the sleeve, a knob fixed to the bolt, a slide having an inner thread engaged with the bolt and having a pair of ribs slidably engaged with the slots of the sleeve so that the slide can be guided to slide longitudinally in the sleeve by rotation of the knob, the lower knife is fixed to the slide.

Abstract: In this overedge sewing machine, when stitch width is adjusted, an adequate excess thread proportional to the adjusted stitch width is obtained. An overedge stitch can be steadily sewn without excessive stitch tension, even when the stitch width increases. By operating one adjustment member, the position of the lower knife holder and the stitch-support member can be easily adjusted, and the stitch width can thus be easily altered.

Abstract: A sewing machine includes a presser foot 9 provided, at the front portion 9a thereof, with an engagement seat 21 through which two ribbon-like pieces of trimmings 15, 16 of different width to be individually and selectively fed to the presser foot, can be sent under a central portion 9b of the latter so that they are engaged by the line of sewing together with the workpiece. An adjustment element 23 is positioned in said engagement seat in order to define the useful width of the seat depending upon the width of the piece of trimmings to be used. A cutting unit 31 is slidably mounted along a guide element 34 and is movable from a rest position in which it is spaced apart sideways from the sewing machine supporting table 3 to a rest position in which it is located close to the supporting table to cut the piece of trimmings previously used.

Abstract: There is disclosed an overedge width regulating device capable of adjusting overedge width by rotating a knob which causes both a overedge-width latch and a lower knife to move simultaneously. The device permits adjustment of the overedge-width latch independently from the lower knife and the release of the overedge-width latch during the roll hemming process. Thus, without regard to material being sewn, knitted or woven, a tight and well-balanced overedge finish is obtained while, at the same time, the overedging process is greatly improved from the viewpoint of both quality and time.

Abstract: Disclosed is a zigzag sewing machine in which a trimming device for trimming the marginal edge of a work fabric is removably disposed at a predetermined position on a machine bed so that the trimming device is driven in relation to the operation of the sewing machine. The zigzag sewing machine comprises a switching device for changing the field position of the needle oscillation and an operated member for actuating the switching device in relation to the disposition of the trimming device at the predetermined position. In this zigzag sewing machine, while overedge stitching is performed by using the trimming device, the field position of the needle oscillation is set so that zigzag stitches having a desired stitch width are always placed along and over the marginal edge of the work fabric trimmed by the trimming device.