Thread tensioner for a sewing machine

• US 8,997,669 B1
• Filed: 10/16/2014
• Issued: 04/07/2015
• Est. Priority Date: 10/16/2014
• Status: Active Grant

• Current Assignee: Handi Quilter
• Original Assignee: Handi Quilter
• Inventors: Ruggles, Bryan K., Konzak, Gary James
• Primary Examiner(s): Worrell, Danny
• Application Number:
  US14/515,780
• Time in Patent Office: 173 Days
• Field of Search: 112/255, 112/254, 242/150.M, 242/150.R, 226/195
• US Class Current: 112/254
• CPC Class Codes: D05B 47/02 Manually-controlled tensioning devices
• CPC Class Codes: D05B 47/04 Automatically-controlled tensioning devices
• CPC Class Codes: D05B 47/06 Applications of tensometers application of tension indicators in handling thin or filamentary material B65H59/40; for embroidery machines D05C11/08; tensometers in general G01L

Abstract

Thread tensioner for a sewing machine. In one example embodiment, a thread tensioner for a sewing machine includes a first disk, a second disk, a spring, a knob, and a sensor. The second disk is positioned next to the first disk. The spring is configured to apply tension to a thread positioned between the first disk and the second disk by exerting a force against the second disk. The spring defines a length between a first end and a second end. The knob is configured, when rotated in one direction, to travel along a threaded shaft toward the spring and thereby cause the length of the spring to shorten. The knob is configured, when rotated in another direction, to travel along the threaded shaft away from the spring and thereby allow the length of the spring to lengthen. The sensor is configured to track a current length of the spring.

Claims

1. A thread tensioner for a sewing machine, the thread tensioner comprising:

a first disk;

a second disk positioned next to the first disk;

a spring configured to apply tension to a thread that is positioned between the first disk and the second disk by exerting a force against the second disk, the spring defining a first end, a second end, and a length between the first end and the second end, the spring being coupled to a rod extending from the second end of the spring;

a knob configured, when rotated in a first direction, to travel along a threaded shaft toward the spring and thereby cause the length of the spring to shorten, the knob further configured, when rotated in a second direction, to travel along the threaded shaft away from the spring and thereby allow the length of the spring to lengthen; and

a sensor configured to track a current length of the spring by tracking the position of the rod.

2. The thread tensioner as recited in claim 1, wherein the sensor is a photodiode array sensor.

3. The thread tensioner as recited in claim 1, wherein the sensor is a magnetic sensor.

4. The thread tensioner as recited in claim 1, wherein:

the threaded shaft is hollow; and

the rod extends through the hollow shaft in order to be tracked by the sensor.

5. The thread tensioner as recited in claim 4, wherein:

the rod extends into an opening in a housing of the sensor; and

the sensor is configured to track the current length of the spring by tracking the position of an end of the rod within the housing of the sensor.

6. The thread tensioner as recited in claim 1, further comprising:

a processor in electronic communication with the sensor and configured to determine a current tension that is being applied to the thread given the current length of the spring.

7. The thread tensioner as recited in claim 6, further comprising:

a display device in electronic communication with the processor and configured to display the current tension.

19. The sewing machine as recited in claim 1, wherein the sensor is a potentiometer sensor configured to track the position of an end of the rod as it interacts with a lever actuator.

8. A thread tensioner for a sewing machine, the thread tensioner comprising:

a first disk;

a second disk positioned next to the first disk;

a hollow threaded shaft;

a spring configured to apply tension to a thread that is positioned between the first disk and the second disk by exerting a force against the second disk, the spring defining a first end, a second end, and a length between the first end and the second end, the spring including a rod extending from the second end of the spring and through the hollow threaded shaft;

a knob configured, when rotated in a first direction, to travel along the threaded shaft toward the spring and thereby cause the length of the spring to shorten and cause the rod to extend further through the hollow threaded shaft in inverse proportion to the shortening of the length of the spring, the knob further configured, when rotated in a second direction, to travel along the threaded shaft away from the spring and thereby allow the length of the spring to lengthen and allow the rod to retract into the hollow threaded shaft in inverse proportion to the lengthening of the length of the spring; and

a sensor configured to track a current length of the spring by tracking a position of an end of the rod.

9. The thread tensioner as recited in claim 8, wherein the sensor is an optical sensor configured to optically track the position of the end of the rod.

10. The thread tensioner as recited in claim 8, wherein the sensor is a magnetic sensor configured to track the position of the end of the rod as it interacts with a magnet.

11. The thread tensioner as recited in claim 8, further comprising:

a processor in electronic communication with the sensor and configured to determine a current tension that is being applied to the thread given the current length of the spring.

12. The thread tensioner as recited in claim 11, further comprising:

a display device in electronic communication with the processor and configured to display the current tension.

13. A sewing machine comprising:

a spool holder;

a needle bar configured to have a needle attached thereto;

an electric motor configured, while the needle is threaded with a top thread from a spool on the spool holder, to repeatedly drive the threaded needle through a fabric to form a row of stitches in the fabric; and

a thread tensioner comprising;

a first disk;

a second disk positioned next to the first disk;

a spring configured, while the top thread is positioned between the first disk and the second disk, to apply tension to the top thread by exerting a force against the second disk, the spring defining a first end, a second end, and a length between the first end and the second end, the spring being coupled to a rod extending from the second end of the spring;

a knob configured, when rotated in a first direction, to travel along a threaded shaft toward the spring and thereby cause the length of the spring to shorten, the knob further configured, when rotated in a second direction, to travel along the threaded shaft away from the spring and thereby allow the length of the spring to lengthen; and

a sensor configured to track a current length of the spring by tracking the position of the rod;

a processor in electronic communication with the sensor and configured to determine a current tension that is being applied to the top thread given the current length of the spring; and

a display device in electronic communication with the processor and configured to display the current tension.

14. The sewing machine as recited in claim 13, wherein:

the rod is integral with the spring.

15. The sewing machine as recited in claim 13, wherein:

the threaded shaft is hollow; and

the rod extends through the hollow shaft in order to be tracked by the sensor.

16. The sewing machine as recited in claim 15, wherein:

the rod extends into an opening in a housing of the sensor; and

the sensor is configured to track the current length of the spring by tracking the position of an end of the rod.

17. The sewing machine as recited in claim 16, wherein the sensor is a magnetic sensor configured to track the position of the end of the rod as it interacts with a magnet.

18. The sewing machine as recited in claim 15, wherein the sensor is a potentiometer sensor configured to track the position of the end of the rod as it interacts with a lever actuator.

20. A thread tensioner for a sewing machine, the thread tensioner comprising:

a first disk;

a second disk positioned next to the first disk;

a spring configured to apply tension to a thread that is positioned between the first disk and the second disk by exerting a force against the second disk, the spring defining a first end, a second end, and a length between the first end and the second end;

a knob configured, when rotated in a first direction, to travel along a threaded shaft toward the spring and thereby cause the length of the spring to shorten, the knob further configured, when rotated in a second direction, to travel along the threaded shaft away from the spring and thereby allow the length of the spring to lengthen; and

a magnetic sensor configured to track a current length of the spring.