Advanced stitching head for making stitches in a textile article having variable thickness
AssigneeMcDonnell Douglas Corporation
InventorsPatrick J. Thrash, Jeffrey L. Miller, Richard Codos
Life of this patent
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Abstract
A stitching head for a computer numerically controlled stitching machine includes a thread tensioning mechanism for automatically adjusting thread tension according to the thickness of the material being stitched. The stitching head also includes a mechanism for automatically adjusting thread path geometry according to the thickness of the material being stitched.
Claims20
A stitching system comprising:
- a stitching machine including a stitching head, the stitching head including a thread tensioning mechanism, the thread tensioning mechanism including a servo for setting thread tension in the stitching head;
- a control station including a computer, the computer including computer memory encoded with data for instructing the computer to command the servo to set the thread tension in the stitching head to desired thread tension values, whereby setting the thread tension is data-driven:
- wherein the thread tensioning mechanism further includes:
- a shaft;
- first and second thread tensioning discs mounted on the shaft;
- means, secured to a first end of the shaft, for applying a bias force that biases the first disc towards the second disc;
- and
- a cam having a cam surface, a second end of the shaft being movable along the cam surface to adjust the bias force;
- a pneumatic cylinder operative on the first and second discs for releasing thread tension;
- and,
- wherein the servo includes a stepper motor for rotating the cam to set the thread tension.
Apparatus for automatically adjusting thread tension in a stitching head, the apparatus comprising:
- a thread tensioning mechanism including a servo, the servo setting the thread tension in response to servo commands;
- a processor;
- computer memory encoded with data including instructions for instructing a computer to generate thread tension values based on thickness values;
- wherein the servo commands are generated from the thread tension values;
- wherein the servo commands are supplied to the servo;
- and,
- wherein the stitching head includes means for adjusting thread path geometry, the computer memory being further encoded with data including instructions for instructing the computer to generate thread path geometry commands based on the thickness values.
A stitching head for stitching a preform made of multiple layers of a variable thickness textile composite, the stitching being performed with a thread made of a composite material, the stitching head comprising:
- a needle;
- reciprocating means for reciprocating the needle;
- a servo-driven thread gripper;
- a servo-driven thread cutter;
- a servo-driven thread path geometry controller for adjusting an amount of the thread used by the needle during stitching of the preform, adjustment of the amount of thread used during the stitching being based upon thickness of the preform;
- and,
- a servo-driven needle cooler, operation of the needle cooler being based upon the thickness of the preform.
Dependencies are inferred from the claim text.