Process for determining the coordinate values for sewing patterns

A device for determining coordinate values of needle touchdown points for forming sewing patterns, comprising:

• an electronically controlled sewing machine including a feed dog extending through slots in a needle plate, said feed dog being drivable in an X coordinate direction corresponding to a normal direction of feed and in a Y coordinate direction extending at right angles to the normal direction of feed and including a drive for moving the needle in the Y coordinate direction;
• a computer connected to said electronically controlled sewing machine via cable means for electronically controlling said electronically controlled sewing machine via said computer;
• a keyboard connected to said computer for entering sewing patterns, each sewing pattern having one or more seam sections;
• display means connected to said computer for displaying sewing patterns entered and a central processing unit associated with said computer for decomposing seam sections of an entered sewing pattern into X and Y coordinate points, determining if the distance between consecutive touchdown points for a straight seam section exceed one of a maximum amount of feed of the feed dog in the X direction and the sum of a maximum amount of needle movement at a particular needle position plus the maximum amount of feed of the feed dog in the Y direction and subdividing the seam section by equidistant intermediate touchdown sites wherein distances between said sites, in the needle movement direction are based on a constant percentage of movement of the needle and a constant percentage of movement of the feed dog and storing said intermediate touchdown sites digitally in a digital storage means associated with said computer.

A process for determining coordinate values of needle touchdown points for forming sewing patterns with an electronically controlled sewing machine, which has a feed dog which extends through slots in a needle plate and is driven in both an X coordinate direction corresponding to a normal direction of feed and in a Y coordinate direction extending at right angles to the normal direction of feed, a drive for moving the needle in the Y coordinate direction, as well as a data processor and a least one memory for storing the coordinate values associated with touchdown points, the process comprising the steps of:

• dividing a seam section, which seam section is determined by two consecutive touchdown points of a needle and is greater in length than a maximum amount of feed of the feed dog in the X coordinate direction and/or greater than the sum of the maximum amount of lateral movement of the needle which is possible at a particular needle position and a maximum amount of feed of the feed dog in the Y coordinate direction;
• providing means for calculating the number of necessary feed movements of the feed dog between the touchdown points of the said seam section after subtracting the possible lateral movement of the needle in the direction of the Y coordinate;
• and
• providing means for adjusting the amount of feed movement of the feed dog by an amount corresponding to the lateral movement of the needle in the direction of the Y coordinate for moving over equal distances between two intermediate touchdown points.