Abstract: Method and apparatus for preparing sewing data for an automatic sewing apparatus which embroiders an embroidery pattern on cloth using a zigzag stitch while moving one or both of a cloth retainer and a sewing machine relative to each other. When a pattern corresponding to a basic sewing data group stored in a memory device is to be embroidered either magnified or reduced in size, in order to set a desired stitch density (P), which is the pitch of the stitches, three items of basic sewing data are read out from the memory device as one processing unit. After these items of data have been multiplied by a specified magnification to obtain sewing data (A,B,C), a pattern range which corresponds to the sewing data is divided by a particular stitch density in order to calculate correction data ( .circle.1 to .circle.21 ).

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: Method and apparatus for preparing sewing data for an automatic sewing apparatus which embroiders an embroidery pattern on cloth using a zigzag chain stitch while moving one or both of a cloth retainer and a sewing machine relative to each other. When a pattern corresponding to a basic sewing data group stored in a memory device is to be embroidered either magnified or reduced in size, in order to set a desired stitch density (P), which is the pitch of the stitches, three items of basic sewing data are read out from the memory device as one processing unit. After these items of data have been multiplied by a specified magnification to obtain sewing data (A,B,C), a pattern range which corresponds to the sewing data is divided by a particular stitch density in order to calculate correction data ( .circle.1 to .circle.21 ).

Abstract: A sewing machine control apparatus is adapted to move a needle rod to a predetermined stitching starting point automatically when a stitching operation is performed, even if a fabric holding body holding an article to be stitched is displaced relative to the needle rod. The apparatus is equipped with operating means for generating a signal which displaces the fabric holding body in an X-Y direction, second control means responsive to the signal for controlling drive means to move the fabric holding body starting means for generating a signal which starts a driving source of the sewing machine, third control means for storing a signal indicative of the position of the fabric holding body while constantly revising the signal, and fourth control means for controlling the drive means in response to the start signal in such a manner that the fabric holding body is moved from any position to the stitching starting position.

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: An input device for sewing machines comprising a means for making visible the sewing pattern up to the inflection point immediately followed by the inflection point to be modified to facilitate the modification of the sewing pattern, a means for inputting the coordinate data of the inflection point to be modified, a means for indicating the contents of the modification, and a means for operating the contents of the modification thus indicated under a predetermined control.

Abstract: There is provided an automatic sewing machine which comprises, a main shaft, a bed, a needle bar having a needle secured to the lower end thereof, a thread straining control device, an operation device and an alarm device.

Abstract: An input device for sewing machines is disclosed which reads from a memory circuit an original sewing pattern which has been already stored, enlarging or reducing the coordinate data of the original sewing pattern in a desired scale, and prepare the coordinate data of sewing points between the flexing points thus obtained by enlargement or reduction in accordance with a desired stitch length data or stitch number data. The input device is adapted to convert the coordinate data of the original sewing pattern to the coordinate data calculated with the central point of a crank member of a work holder with the crank member as the origin and enlarge or reduce the coordinate data of the flexing points other than the starting point and the ending point of sewing in a desired scale, when the original sewing pattern is for a work holder with a crank member.

Abstract: A thread tightening control apparatus according to the present invention is capable of tightening upper and under threads accurately and in good order, irrespective of fabric thickness, by the relative movement between a needle and a fabric holding body.The apparatus is provided with setting means capable of generating a plurality of setting signals of different timings at which the drive pulses are to be supplied to the drive means in dependence upon fabric thickness. Shifting means is operable in association with a selected setting signal for moving a period during which drive means is supplied with drive pulses by the actuating means forward or backward with respect to a predetermined rotational angle of a spindle. As a result, the distance between the tip of the needle and the surface of the fabric at the completion of fabric feed is set to a predetermined minimum length irrespective of fabric thickness.