Apparatus for making a three needle stitch with cover thread

A sewing machine for producing a stitch comprising three rows of closely and equally spaced stitches, each row of stitches formed from a needle thread and a looper thread, and wherein the mechanism for producing this stitch includes:

• a reciprocating needle bar;
• a throat plate having feed dog openings formed therein;
• a feed dog including material engaging portions adapted to extend through said feed dog openings to advance the material in the direction of material feed;
• a needle head mounting three needles, said three needles laying in a vertical plane and the point of the right needle being at a higher elevation than the corresponding points of the left and the middle needles;
• said needle head being secured to said needle bar such that said vertical plane of said needle head is at an acute angle to the direction of material feed;
• a looper rocker, mounted to pivot about an axis that is parallel to said direction of material feed, said looper rocker carrying three loopers, each arranged to cooperate with one of said needles and each having a looper point;
• the looper point, of the looper arranged to cooperated with the left needle, spaced from the looper point of the looper arranged to cooperate with the middle needle, by an amount corresponding to the spacing between the left and middle needles;
• the looper point, of the looper arranged to cooperated with the middle needle, spaced from the looper point of the looper arranged to cooperate with the right needle, by an amount corresponding to the spacing between the middle and right needles;
• and
• the point of the looper arranged to cooperate with the right needle is located in the radial direction relative to the looper rocker pivot axis further from the looper rocker axis than the points of the loopers arranged to cooperate with the left and middle needles.

A sewing machine for producing a stitch comprising, three rows of closely and equally spaced stitches, each row of stitches being formed from a needle thread and a looper thread;

• and a spreader thread interlaced with the three rows of stitches;
• wherein the mechanism for producing this stitch includes:
• a reciprocating needle bar;
• a throat plate having feed dog openings formed therein;
• a feed dog including material engaging portions adapted to extend through said feed dog openings to advance the material in the direction of material feed;
• a needle head mounting three needles, said three needles laying in a vertical plane and the point of the right needle being at a higher elevation than the corresponding points of the left and the middle needles;
• said needle head being secured to said needle bar such that said vertical plane of said needle head is at an acute angle to the direction of material feed;
• a looper rocker, mounted to pivot about an axis that is parallel to said direction of material feed, said looper rocker carrying three loopers, each arranged to cooperated with one of said needles and each having a looper point;
• the looper point, of the looper arranged to cooperated with the left needle, is spaced from the looper point of the looper arranged to cooperate with the middle needle, by an amount corresponding to the spacing between the left and middle needles;
• the looper point, of the looper arranged to cooperated with the middle needle, is spaced from the looper point of the looper arranged to cooperate with the right needle, by an amount corresponding to the spacing between the middle and right needles;
• and
• oscillating spreader mechanism, including an auxiliary spreader that is connected thereto, for casting said spreader thread such that it is interwoven by the stitches formed by said three needles.