Abstract: A workpiece cloth ruler is disclosed which is detachably attachable to an attaching part of a cloth presser holder or a walking foot to which a cloth presser is attached to press workpiece cloth. The ruler includes a bar-shaped support detachably attachable to the attaching part of the cloth presser holder so as to be directed in a right-left direction and so as to be substantially horizontal, a connecting part located on an end of the bar-shaped support, a cloth guide connected via a supporting part to the connecting part of the bar-shaped support so as to be vertically pivotable, and an elastic member biasing the cloth guide to the workpiece cloth side so that the cloth guide pivots.

Abstract: A needle plate includes a first needle plate fixed to a sewing machine bed and having a needle hole through which a sewing needle is penetratable and a square hole through which a feed dog for feeding a workpiece cloth is projected and retracted; a second needle plate positioned in front of the first needle plate and above a horizontal hook mechanism and detachably attached to the first needle plate; an engagement mechanisms in which the second needle plate is slid into engagement with the first needle plate; and a disengagement mechanism for disengagement of the engagement mechanisms.

Abstract: A zigzag sewing machine including a needle bar having a sewing needle attached thereto, a needle swing mechanism that laterally swings the needle bar, a needle plate disposed on an upper surface of a sewing machine bed, and a feed dog constituted by a first to fourth teeth that feed a workpiece cloth by projecting/retracting from the needle plate. The zigzag sewing machine further includes a feed dog longitudinal transfer mechanism that longitudinally moves the feed dog, a feed dog lateral transfer mechanism that laterally moves the feed dog, and a control unit that controls the feed dog lateral transfer mechanism so that one of the teeth is associated with a needle drop point of the sewing needle.

Abstract: A needle plate includes a first needle plate fixed to a sewing machine bed and having a needle hole through which a sewing needle is penetratable and a square hole through which a feed dog for feeding a workpiece cloth is projected and retracted; a second needle plate positioned in front of the first needle plate and above a horizontal hook mechanism and detachably attached to the first needle plate; an engagement mechanisms in which the second needle plate is slid into engagement with the first needle plate; and a disengagement mechanism for disengagement of the engagement mechanisms.