Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Takayuki Wakana

Satomi Yamauchi

A sewing machine apparatus driven by a motor, which is subject to velocity control on the basis of a detector for determining the rotary position and/or velocity of the motor output shaft. A controller is operative to control the speed of the motor in accordance with a velocity command value. A means for generating a holding force during a stop of the sewing machine ensures that the sewing needle does not provide unwanted movement. The holding force is changed when movement from the stop position is desired, as by changing the force in relation to the speed or amount of movement. This feature is particularly useful to reduce the load presented to an operator who wishes to manually change the machine position.

Sewing mahine drive apparatus and method

A sewing control system for controlling the speed of rotation of a sewing machine in which in a first embodiment, a rotation transfer ratio operation is inhibited during the time that slip occurs. According to a second embodiment, the rotation transfer operation is initiated only when the number of revolutions of the motor shaft is higher than a predetermined value. In a third embodiment, slip is prevented by not outputting a speed instruction which is not steeper than a predetermined gradient. In a fourth embodiment, when an abnormal condition is detected, the rotation transfer ratio is reduced in order to reduce the speed of the motor, thereby assuring the safety of an operator.

Growing community of inventors

Aichi, Japan

Takayuki Wakana