Abstract: A method and apparatus for inputting stitch patterns by way of a digitizer is effective to record stitching patterns which involve skipping and which extend beyond the digitizer board. In a method aspect, where stitch patterns involve skipping and the drawings of the patterns exceed beyond the digitizer plotting board, a method is provided including the steps of commanding scale-down input coordinate values and converting the input coordinate values to scale-up values to recover the reduced value. In an apparatus aspect, an input device is provided comprising a digitizer for drawing stitching patterns, control circuitry for performing scaling function, and command generating circuitry for commencing the scaling activity.

Abstract: An input device for a sewing machine is partially provided in a portable unit connectable to a sewing machine. Efficiencies are achieved by relying on input portions present in the sewing machine. The portable input device includes control portions for inputting a stitch pattern, test running a stitch pattern, modifying a stitch pattern, writing a stitch pattern, and reading a stitch pattern. When the portable input device is coupled to the sewing machine, the stitch patterns may be executed.

Abstract: A movement control apparatus for a sewing machine to automatically control movement initiating timing corresponding to various sewing machine speeds.

Abstract: An input device for an electronically controlled sewing machine is effective for inputting stitch patterns which are partially prohibited from scaling up or scaling down. A control circuit is signalled that points of a stitching pattern are not to be scaled. A check bit added to the coordinate value of prohibited-scaling stitch points flags the scaling prohibition condition.

Abstract: A thread cutting mechanism for a lock stitch sewing machine which comprises a stationary blade, a reciprocally movable blade, operation means for moving the movable blade reciprocally and adjusting means for adjusting the reciprocal movement distance of the movable blade so as to vary the operative position with the initial position maintained constant. The movable blade includes a thread handling portion, a thread cutting knife portion, a thread arresting portion and a thread guide portion.

Abstract: A sewing machine having a work holder with a crank member in which a computing device is provided for computing coordinate values in accordance with the configuration of the work holder with the crank member and particularly, designed to convert coordinate values of a reference sewing pattern into coordinate values with the center of the crank member on the work holder with the crank member as the origin when the sewing pattern is enlarged or reduced in scale. When work holder with the crank member is returned to the sewing start point on the sewing pattern, the work holder with the crank member is returned in the direction of the X axis or Y axis depending upon the positional relationship between the existing position of the work holder with the crank member and a reference value.

Abstract: A sewing machine with a workpiece holding-down device comprises an arm movable between an upper position and a lower position and normally biased to the upper position. An auxiliary workpiece holding-down member is movable between an upper position and a lower position in synchronization with the rotation of a main shaft and is normally biased to the upper position. A disengageable interconnecting means is interposed between the main shaft and auxiliary holding-down member. Electromagnetic means is energized upon starting of a sewing operation and is deenergized upon the completion of formation of a seam. An operation means is operable in response to energization of the electromagnetic means to impart an operative force to the auxiliary holding-down member and a holding-down arm and releases the operative force in response to the deenergization of the electromagnetic means.