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 foot-operated controller of a sewing machine including a first pedal that input a number of revolution of a sewing machine motor by stepping of a user, a second pedal pressed by the user, a main body that supports the first pedal, and a support unit that supports the second pedal, in which the support unit is selectively attachable in disposition where the second pedal is on the left side of the first pedal and disposition where the second pedal is on the right side of the first pedal. In both cases where the second pedal is on the left side of the first pedal and the right side of the first pedal, across an interval between the main body and the support unit, it is possible to detect the pressing to the second pedal with respect to the second element.

A foot-operated controller of a sewing machine including a first pedal that input a number of revolution of a sewing machine motor by stepping of a user, a second pedal pressed by the user, a main body that supports the first pedal, and a support unit that supports the second pedal, in which the support unit is selectively attachable in disposition where the second pedal is on the left side of the first pedal and disposition where the second pedal is on the right side of the first pedal. In both cases where the second pedal is on the left side of the first pedal and the right side of the first pedal, across an interval between the main body and the support unit, it is possible to detect the pressing to the second pedal with respect to the second element.

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 closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A sewing machine including a detection portion that detects a movement amount of a workpiece, a sewing machine motor that serves as a driving source for vertical movement of a needle bar, and a control device that controls the sewing machine motor based on the detection result by the detection portion and performs control to maintain a constant stitch pitch. The control device lengthens a period for obtaining an output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is decreased, and shortens the period for obtaining the output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is increased.

A sewing machine including a detection portion that detects a movement amount of a workpiece, a sewing machine motor that serves as a driving source for vertical movement of a needle bar, and a control device that controls the sewing machine motor based on the detection result by the detection portion and performs control to maintain a constant stitch pitch. The control device lengthens a period for obtaining an output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is decreased, and shortens the period for obtaining the output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is increased.