A memory of a sewing machine stores a plurality of notification conditions for notifying an information processing device of an extent of progress of sewing of the embroidery pattern. The notification conditions include a first notification condition for notifying that the extent of progress is a first extent and a second notification condition for notifying that the extent of progress is a second extent. The sewing machine transmits, to the information processing device, first extent information indicating the first extent, when the sewing machine determines that the first notification condition is satisfied. The sewing machine transmits, to the information processing device, the second extent information indicating the second extent, when the sewing machine determines that the second notification condition is satisfied.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

A sewing machine includes: a pattern data acquisition unit that acquires pattern data in which information on an object corresponding to a unit from a sewing start point to a ravel preventing point or a thread trimming point and information related to a required bobbin thread amount required for sewing the object are associated with each other and registered; a bobbin thread remaining amount acquisition unit that acquires a bobbin thread remaining amount; a determination unit that determines whether or not the object is sewable, based on a difference between a required bobbin thread amount of the object according to the pattern data and the bobbin thread remaining amount; and a decision unit that, based on a determination result of the determination unit, decides whether or not the object is set as a sewing target.

The present invention provides a thread feeding device of a decorative stitching sewing machine. The thread feeding device feeds a needle thread, an upper looper thread, and a lower looper thread in the amounts required for sewing one stitch such that the position of a stitch looping point of the threads changes. The thread feeding device includes: a thread accumulator 500 having thread accumulating elements 13a to 13d and 14a to 14d which measure the thread accumulation amounts of predetermined lengths of the needle thread, the upper looper thread, and the lower looper thread, and thread accumulation amount control elements 15 to 18 which adjust the amounts of the threads required for sewing one stitch in an increasable and decreasable manner within the range of thread accumulation amounts of predetermined lengths at the time of fabric feeding, and which release the threads to a stitch forming device when a stitch is formed; a thread feed drive mechanism 600 which drives each of the elements; and a thread feed control unit having a program which dives the thread accumulation amount control elements for each stitch to feed the threads in an increasable and decreasable manner so as to increase or decrease the threads within the range of a total thread feeding amount that is maintained constant, including a fabric feeding amount, a fabric thickness and an overlocking width, thereby to change the position of the stitch looping point of the needle thread, the upper looper thread, and the lower looper thread, thus controlling the decorative stitching according to a stitching decoration pattern.

The present invention provides a thread feeding device of a decorative stitching sewing machine. The thread feeding device feeds a needle thread, an upper looper thread, and a lower looper thread in the amounts required for sewing one stitch such that the position of a stitch looping point of the threads changes. The thread feeding device includes: a thread accumulator 500 having thread accumulating elements 13a to 13d and 14a to 14d which measure the thread accumulation amounts of predetermined lengths of the needle thread, the upper looper thread, and the lower looper thread, and thread accumulation amount control elements 15 to 18 which adjust the amounts of the threads required for sewing one stitch in an increasable and decreasable manner within the range of thread accumulation amounts of predetermined lengths at the time of fabric feeding, and which release the threads to a stitch forming device when a stitch is formed; a thread feed drive mechanism 600 which drives each of the elements; and a thread feed control unit having a program which dives the thread accumulation amount control elements for each stitch to feed the threads in an increasable and decreasable manner so as to increase or decrease the threads within the range of a total thread feeding amount that is maintained constant, including a fabric feeding amount, a fabric thickness and an overlocking width, thereby to change the position of the stitch looping point of the needle thread, the upper looper thread, and the lower looper thread, thus controlling the decorative stitching according to a stitching decoration pattern.

Disclosed is a sewing machine which evaluates sewing quality using a stitch tightness index. During sewing operation, a used length of an upper thread per stitch is detected, and a stitch tightness index per sewn stitch is calculated on the basis of a stitch length per stitch defined by sewing pattern data, a fabric thickness of a sewing workpiece, and detected data of the used length of the upper thread. Then, notification is made which corresponds to the calculated stitch tightness index per sewn stitch (such as a visual display of the stitch tightness index). After that, acceptability/non-acceptability of the thread tightness per sewn stitch can be determined by comparing the calculated stitch tightness index per sewn stitch against a reference value, and a result of the determination can be notified.

Disclosed is a sewing machine which evaluates sewing quality using a stitch tightness index. During sewing operation, a used length of an upper thread per stitch is detected, and a stitch tightness index per sewn stitch is calculated on the basis of a stitch length per stitch defined by sewing pattern data, a fabric thickness of a sewing workpiece, and detected data of the used length of the upper thread. Then, notification is made which corresponds to the calculated stitch tightness index per sewn stitch (such as a visual display of the stitch tightness index). After that, acceptability/non-acceptability of the thread tightness per sewn stitch can be determined by comparing the calculated stitch tightness index per sewn stitch against a reference value, and a result of the determination can be notified.