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AssigneeJanome Sewing Machine Co., Ltd.
InventorsHachiro Makabe, Kazuo Watanabe, Hideaki Takenoya, Eiichi Shomura, Yoshinobu Tonomura
Estimating the term…
When a pulse motor in an electronic sewing machine is to be subjected to a heavy load, the pulse motor is operated at a slower speed in order to cause the pulse motor to operate at a rate in which it has a maximum torque output. For lesser load conditions, pulse motor speed is allowed to increase. Speed control of the pulse motor follows a generally trapezoidal curve, which curve includes a speed-up section and a slow-down section, and may include a flat section. That portion of the generally trapezoidal curve along which motor speed follows is determined by the distance which the pulse motor is required to move.
An improvement to a sewing machine in which a pulse motor is subjected to a lesser load during straight stitching and to a greater load during a movement of a mechanism from an initial first mechanism position to a desired second mechanism position, comprising:
Dependencies are inferred from the claim text.