Method to automatically control thread tension

Abstract

The present invention relates to automatically controlling the tension of thread sewn while operating a sewing machine The system for controlling the tension of thread being used includes a wheel or other gripping mechanism that is in mechanical communication with a motor. When voltage and/or current is provided to the motor via electronic circuitry, the motor “pulls” on the thread with the desired force in a direction opposite to how the thread normally flows. The voltage and/or current delivered to the motor may be adjusted by a user. When the motor pulls on a thread to provide tension, the tension may be maintained independently of the sliding friction of the thread. As such, the tension is very accurate and repeatable, and provides for a tension that cannot be achieved with currently existing sewing machines.

What is claimed is: 
     
         1 . A system for automatically controlling thread tension of thread flowing toward material to be stitched, the system comprising:
 a wheel for gripping thread to be used during sewing;   a motor for controlling the operation of the wheel;   a shaft connecting the wheel to the motor such that when the motor is activated, the shaft and wheel are rotated and tension is applied to thread on the wheel in a direction opposite of the material to be stitched; and   an input device in communication with the motor for applying at least one of a voltage and current which is proportional to a desired amount of tension to the motor.   
     
     
         2 . The system of  claim 1 , wherein the motor is one of a: DC servo, BLDC, Stepper, AC, Pneumatic, or Hydraulic motor. 
     
     
         3 . The system of  claim 1 , wherein the system further includes an encoder in electronic communication with the motor for measuring at least one of: the amount of thread and thread velocity. 
     
     
         4 . The system of  claim 3 , wherein the encoder acts as a thread break detection device. 
     
     
         5 . The system of  claim 1 , wherein the input device is one of a: tablet computer, personal computer, and a knob. 
     
     
         6 . A method for automatically controlling thread tension of thread flowing toward material to be stitched, the method comprising the steps of:
 providing a selection of a tension, that corresponds to at least one of a voltage and current, into an input device;   transmitting at least one of said voltage and current to a motor via electronic circuitry;   said motor pulling on a shaft in mechanical connection with a wheel for gripping thread, wherein said wheel is pulled by said shaft in a direction opposite of material to be stitched, the at least one of the voltage and current causing said motor to create the selected tension in the thread; and   said one of a voltage and current delivered being adjustable via said input device.   
     
     
         7 . The method of  claim 6 , wherein the motor is one of a: DC servo, BLDC, Stepper, AC, Pneumatic, or Hydraulic motor. 
     
     
         8 . The method of  claim 6 , further comprising the step of measuring at least one of: the amount of thread and thread velocity via an encoder in electronic communication with the motor. 
     
     
         9 . The method of  claim 8 , wherein the encoder is also able to detect a break in thread. 
     
     
         10 . The method of  claim 6 , wherein the input device is one of a: tablet computer, personal computer, and a knob. 
     
     
         11 . A system for automatically controlling thread tension of thread flowing toward material to be stitched, the system comprising:
 a motor;   a shaft attached to said motor;   a wheel for gripping thread to be used during sewing also attached to said shaft, wherein when the motor is activated, the shaft and wheel are rotated and tension is applied to thread on the wheel in a direction opposite to material to be stitched; and   an input device connected to the motor for applying at least one of a voltage and current which is proportional to a desired amount of tension to the motor.   
     
     
         12 . The system of  claim 11 , wherein the motor is one of a: DC servo, BLDC, Stepper, AC, Pneumatic, or Hydraulic motor. 
     
     
         13 . The system of  claim 11 , wherein the system further includes an encoder in electronic communication with the motor for measuring at least one of: the amount of thread and thread velocity. 
     
     
         14 . The system of  claim 13 , wherein the encoder acts as a thread break detection device. 
     
     
         15 . The system of  claim 11 , wherein the input device is one of a: tablet computer, personal computer, and a knob.