A driving clutch device for a sewing machine includes a drive shaft, a passive member, a clutch seat, an actuating seat, a power unit, and a clutch member. Through fixing the passive member and the clutch seat onto the drive shaft, rotatably disposing the actuating seat, the drive shaft, and returnably disposing the clutch member to the clutch seat, the clutch seat and the actuating seat are able to move synchronously when the clutch member is in the engaged position, but not to move synchronously when the clutch member in the disengaged position, thereby achieving the driving and clutch controls only by the clutch member, the passive member, the clutch seat and the actuating seat. Therefore, the driving clutch device is simpler and the driving is more direct and instant, thereby reducing assembly costs and the error of action coordination.

A driving clutch device for a sewing machine includes a drive shaft, a passive member, a clutch seat, an actuating seat, a power unit, and a clutch member. Through fixing the passive member and the clutch seat onto the drive shaft, rotatably disposing the actuating seat, the drive shaft, and returnably disposing the clutch member to the clutch seat, the clutch seat and the actuating seat are able to move synchronously when the clutch member is in the engaged position, but not to move synchronously when the clutch member in the disengaged position, thereby achieving the driving and clutch controls only by the clutch member, the passive member, the clutch seat and the actuating seat. Therefore, the driving clutch device is simpler and the driving is more direct and instant, thereby reducing assembly costs and the error of action coordination.

A position indicating circuit includes: first and second input terminals for respectively receiving first and second voltages; an output terminal; a first resistor; and a second resistor having a first terminal coupled to the first input terminal through the first resistor, a second terminal coupled to the second input terminal, and a third terminal coupled to the output terminal. The second resistor is used to be actuated by a pedal of a foot controller of a sewing machine such that a voltage at the output terminal has a magnitude related to a position of the pedal. A detecting system that uses the position indicating circuit and that can determine whether the foot controller is coupled to a main body of the sewing machine is also provided.

A position indicating circuit includes: first and second input terminals for respectively receiving first and second voltages; an output terminal; a first resistor; and a second resistor having a first terminal coupled to the first input terminal through the first resistor, a second terminal coupled to the second input terminal, and a third terminal coupled to the output terminal. The second resistor is used to be actuated by a pedal of a foot controller of a sewing machine such that a voltage at the output terminal has a magnitude related to a position of the pedal. A detecting system that uses the position indicating circuit and that can determine whether the foot controller is coupled to a main body of the sewing machine is also provided.

A sewing machine includes a movement amount detector which is configured to detect a movement amount of a workpiece, a motor which is a rotation driving source of an upper shaft configured to provide a vertical motion to a needle bar, and a control device which is configured to control the motor based on detection of the movement amount detector to maintain a constant stitch length. The movement amount detector is supported to be capable of being raised and lowered around a stitch position. The sewing machine includes a pressing unit configured to provide an upward elastic force such that a detection surface of the movement amount detector protrudes from an upper surface of a throat plate.

A sewing machine includes a movement amount detector which is configured to detect a movement amount of a workpiece, a motor which is a rotation driving source of an upper shaft configured to provide a vertical motion to a needle bar, and a control device which is configured to control the motor based on detection of the movement amount detector to maintain a constant stitch length. The movement amount detector is supported to be capable of being raised and lowered around a stitch position. The sewing machine includes a pressing unit configured to provide an upward elastic force such that a detection surface of the movement amount detector protrudes from an upper surface of a throat plate.

The present invention provides a system and method for the application of a functional thread to secure roving or other fibers to a substrate, thereby forming a precursor to a resultant composite component structure having targeted, enhanced structural reinforcement. The functional thread may be comprised of one or more fibrous filaments or have a monofilament structure. The invention encompasses the sewing of this functional thread at varying stitch densities as function of component stress analysis, the mechanical stresses that the component will be subject to when exposed to the forces and loads associated with its intended use, and at least one physical or mechanical property of a functional thread. This variable stitch density serves to provide targeted, localized mechanical enhancement and reinforcement to the resultant composite structure.

The present invention provides a system and method for the application of a functional thread to secure roving or other fibers to a substrate, thereby forming a precursor to a resultant composite component structure having targeted, enhanced structural reinforcement. The functional thread may be comprised of one or more fibrous filaments or have a monofilament structure. The invention encompasses the sewing of this functional thread at varying stitch densities as function of component stress analysis, the mechanical stresses that the component will be subject to when exposed to the forces and loads associated with its intended use, and at least one physical or mechanical property of a functional thread. This variable stitch density serves to provide targeted, localized mechanical enhancement and reinforcement to the resultant composite structure.

A sewing machine of the present embodiment comprises a movement amount detector which detects a movement amount of fabric, a sewing machine motor serving as a rotary drive source of an upper shaft which applies vertical movement to a needle bar, a shaft angle detector which detects a shaft angle of an output shaft of the upper shaft or the sewing machine motor, and a controller which controls the sewing machine motor based on the detection of the movement amount detector and performs controls of maintaining a constant stitch length. The controller performs controls of maintaining the constant stitch length, by a movement amount of the fabric detected by the movement amount detector in a shaft angle section where a sewing needle is not stuck into a cloth, based on the detection by the shaft angle detector.

A sewing machine of the present embodiment comprises a movement amount detector which detects a movement amount of fabric, a sewing machine motor serving as a rotary drive source of an upper shaft which applies vertical movement to a needle bar, a shaft angle detector which detects a shaft angle of an output shaft of the upper shaft or the sewing machine motor, and a controller which controls the sewing machine motor based on the detection of the movement amount detector and performs controls of maintaining a constant stitch length. The controller performs controls of maintaining the constant stitch length, by a movement amount of the fabric detected by the movement amount detector in a shaft angle section where a sewing needle is not stuck into a cloth, based on the detection by the shaft angle detector.