Abstract: A buttonhole forming apparatus includes a cutter, a cutter driving mechanism, and a needle plate. The needle plate has a needle plate base to hold a work cloth thereon and a pair of cutter guides in a recess to guide an edge of the cutter therein. The cutter guides are made of hard material on the inside and rubber on the outside. The hard material can be moved outward by the resilience of the rubber. The width of the cutter hole defined between the cutter guides is set as small as possible so that the cutter does not force the work cloth into the cutter hole when it is lowered where it remains clogged. When the cutter is gradually lowered, the edge of the cutter or a part of the work cloth to be cut makes contact with the tapered portions of the cutter guides, and the rubber is deformed to move the cutter guides outward.

Abstract: In a buttonhole sewing machine, a sewing mechanism and a feed bracket are controlled to form a buttonhole defined by settings, such as zigzag stitch length, zigzag pitch, bar-tack length, bar-tack pitch, and cutter space. The buttonhole can be set on the operation panel and changed to various shapes by changing the above settings. In particular, the left and right zigzag stitch widths can be set differently, and the front and rear bar-tack lengths can be also set differently. Thus, the balance of the buttonhole can be finely adjusted.

Abstract: A sewing machine is provided with an X-correction value input unit that corrects, in an X-direction, seam position with respect to a position of an opening, e.g., a circular hole, formed in a workpiece cloth by an opening forming mechanism, and an X-direction seam data correction unit that corrects seam data based on an X correction value inputted from the X-correction value input unit. The sewing machine can also be provided with an Y-correction input unit and a Y-direction seam data correction unit for correcting Y-direction information in the seam data. With the seam data corrected by the seam data correction units, a seam position can be corrected with respect to the position of the opening formed by the opening forming mechanism.

Abstract: A buttonhole sewing machine including stitching instrumentalities for forming zigzag stitches defining an eyelet-end buttonhole having an eyelet end portion at one end of a foot portion, by operations of a driving mechanism for operating a needle and looper device of the stitching instrumentalities, a feeding mechanism for feeding work fabric feeding table along X and Y axes, and a rotating mechanism for rotating a needle bar and looper base about an axis perpendicular to the X and Y axes, according to stitching data, and wherein the stitching data are compensated by a control device according to a designated one of compensation data sets stored in a compensation data memory.

Abstract: A buttonhole sewing machine including stitching instrumentalities for forming zigzag stitches defining an eyelet-end buttonhole having an eyelet end portion at one end of a foot portion, by operations of a driving mechanism for operating needle and looper device of the stitching instrumentalities, a feeding mechanism for feeding work fabric feeding table along X and Y axes, and a rotating mechanism for rotating needle bar and looper base about an axis perpendicular to the X and Y axes, according to primary stitching data, and wherein a data input device is provided for operation by an operator to specify at least one characteristic of a bar tack portion to be formed at the other end of the foot portion of the eyelet-end buttonhole, and a data generating device is provided for generating tacking data as secondary stitching data on the basis of the specified characteristic or characteristics, to stitch the bar tack portion.

Abstract: An apparatus for modifying sewing data to control a sewing machine including (a) a stitch-forming device for forming stitches on at least one work sheet, (b) a work-holding device for holding the work sheet, and (c) a displacing device for displacing at least one of the stitch-forming device and the work-holding device, relative to each other, according to the sewing data, the sewing machine having a prescribed coordinate system, the apparatus including a plurality of detectable objects located at a plurality of fixed positions spaced apart from each other on the work-holding device, respectively; a position detector which detects an actual position of each of the detectable objects in the prescribed coordinate system of the sewing machine; and a data modifying device for modifying the sewing data based on a difference of the detected actual position of the each of the detectable objects from a corresponding one of respective reference positions of the detectable objects in the prescribed coordinate system of