Optimized backing shifter for variable or multi-gauge tufting

A method of operating a tufting machine of the type having a control system and

• a needle bar movable toward and away from a backing fabric by operation of a needle drive, said needle bar carrying a series of gauge-spaced and yarn-carrying needles transversely across a width of the tufting machine;
• a backing feed feeding the backing fabric through a tufting zone of the tufting machine;
• a yarn feed mechanism for feeding yarns of a single color to the series of needles;
• a precision backing shifter for shifting the backing transversely relative to the tufting zone;
• a needle plate beneath the backing fabric equipped for reciprocal front-to-back movement;
• a series of gauge spaced parts mounted below the tufting zone in a position to engage the series of needles when penetrating the backing fabric by downward movement of the needle bar to form tufts of yarns in the backing material;
• comprising feeding the backing fabric from front to rear through the tufting machine while operating the needle drive to cause the series of yarn-carrying needles to penetrate the backing fabric when the needle plate is moved frontward, and shifting the backing fabric relative to the needles and gauge parts when the needle plate is moved rearward, the shifting of the backing fabric relative to the needles for some penetrations of the needles by increments less than the gauge spacing of the needles creating a tufted fabric without streaking.

A tufting machine for forming tufted fabrics, comprising:

• a needle bar movable toward and away from a backing fabric by operation of a needle drive, said needle bar carrying a series of gauge-spaced yarn-carrying needles transversely across a width of the tufting machine;
• a backing feed feeding the backing fabric through a tufting zone of the tufting machine;
• a yarn feed mechanism for feeding yarns to the series of needles;
• a backing shifter for shifting the backing transversely relative to the tufting zone;
• a needle plate beneath the backing fabric equipped for reciprocal front-to-back movement;
• a series of gauge spaced parts mounted below the tufting zone in a position to engage the series of needles when penetrating the backing fabric by downward movement of the needle bar to form tufts of yarns in the backing material;
• a control system for controlling and synchronizing the backing shifter, the needle drive, the backing feed, and the front-to-back movement of the needle plate.