Spindle tension system for sewing station

A spindle assembly for a sewing machine for advancing a looped end textile work piece during a cycle of operation of the sewing machine along a processing path through the sewing machine, the sewing machine having a sewing head and a work surface, said spindle assembly comprising:

• a plurality of spindles positioned along the processing path for advancing the work piece along the processing path, one of said spindles comprising a tension adjustment spindle for adjusting the tension in the work piece movably mounted to a stationary spindle support;
• spindle shifting means connected to said tension adjustment spindle and said stationary spindle support and arranged to move said tension adjustment spindle with respect to said stationary spindle support at the beginning of the cycle of operation of the sewing machine in a direction to apply a predetermined initial tension to the work piece;
• spindle support position adjustment means adapted to move said spindle support toward or away from the sewing machine, and spindle support locking means for releasably locking said spindle support in a fixed position with respect to said sewing machine;
• and
• tension control means for substantially continuously applying a predetermined operating tension to the work piece after said spindle shifting means has applied an initial tension to the work piece as the work piece is advanced along the processing path during the cycle of operation of the sewing machine.

A method of applying a predetermined substantially constant tension to a looped end textile work piece as the work piece is advanced along a processing path through and is sewn by a sewing machine, comprising the steps of:

• placing the looped end of the work piece about approximately parallel, horizontally extending spindles which straddle the sewing machine and extending the looped end of the work piece through the sewing machine;
• moving one of the spindles with respect to the sewing machine in a direction to apply a predetermined amount of initial tension to the looped end of the work piece:
• in response to a predetermined initial tension being applied to the looped end of the work piece;
• maintaining the movable spindle in a fixed position;
• advancing the looped end of the work piece through the sewing machine and about the spindles;
• sewing the work piece with the sewing machine through a cycle of operation of the sewing machine;
• and
• continuously applying a predetermined force to the looped end of the work piece in a direction to compensate for changes in tension in the work piece and maintain a substantially constant operating tension to the looped end of the work piece during the cycle of operation of the sewing machine.

A guide system for advancing a looped end of a textile work piece along a processing path through a sewing machine, said guide system including:

• spindles positioned along the processing path arranged to advance the looped end of the work piece along the processing path and through the sewing machine;
• one of said spindles comprising a tension adjustment spindle for adjusting the tension of the work piece;
• a spindle mount, said tension adjustment spindle mounted to said spindle mount;
• a stationary spindle support;
• spindle shifting means interconnected between said stationary spindle support and said spindle mount for moving said spindle mount and said tension adjustment spindle with respect to said stationary spindle support in a direction to change the length of the processing path and to change the tension in the work piece;
• a tension arm having a first end pivotally mounted to said spindle mount and movable with said tension adjustment spindle and having a distal end movable in an arc;
• a tension roller rotatably mounted to the distal end of said tension arm in a position for moving into engagement with the work piece and applying tension to the work piece;
• biasing means connected to said tension arm for urging said tension roller into engagement with the work piece with a predetermined continuous force;
• and
• switch means positioned adjacent said tension arm for determining the position of said tension arm and for terminating the movement of said spindle mount in response to said tension arm moving to a predetermined position.