An apparatus and method for applying stitches to a decorative component having a three dimensional configuration is provided. A head for applying stitches to a decorative component having a three dimensional configuration, including: a needle bar assembly operatively coupled to the head; a looper configured to cooperate with the needle bar assembly in order to prove a plurality of stitches in the decorative component, the looper rotating in a plane parallel to the decorative component; a post assembly configured to drive the looper in a reciprocating fashion in the plane, wherein the post assembly is operatively coupled to a motor configured to drive the needle bar assembly in a reciprocating fashion, the post assembly being operatively coupled to the head via a cylinder arm assembly and a downshaft assembly; and wherein the cylinder arm assembly is rotated in a synchronized manner with a rock frame through mechanical linkage connecting a rock frame drive shaft to the cylinder arm assembly.

A sewing machine according to the present invention includes: an upper shaft that drives a needle and a balance; a lower shaft that drives a hook and a feed dog; an upper and lower shaft belt that synchronizes rotation of the upper shaft with rotation of the lower shaft; and an idler unit that pushes an idler into the upper and lower shaft belt to change a tension side belt length, in which the idler unit includes a transmission mechanism connected to the upper shaft or the lower shaft, and a rotating body mechanism provided with the idler and having a rotating body that rotates in synchronization with the upper shaft or the lower shaft by the transmission mechanism, and a pushing amount of the idler into the upper and lower shaft belt is changed according to rotation of the rotating body.

A sewing machine according to the present invention includes: an upper shaft that drives a needle and a balance; a lower shaft that drives a hook and a feed dog; an upper and lower shaft belt that synchronizes rotation of the upper shaft with rotation of the lower shaft; and an idler unit that pushes an idler into the upper and lower shaft belt to change a tension side belt length, in which the idler unit includes a transmission mechanism connected to the upper shaft or the lower shaft, and a rotating body mechanism provided with the idler and having a rotating body that rotates in synchronization with the upper shaft or the lower shaft by the transmission mechanism, and a pushing amount of the idler into the upper and lower shaft belt is changed according to rotation of the rotating body.

Provided is a double-needle lockstitch sewing machine that can easily sew a fabric rolled into a tubular shape by two rows of lockstitch. The double-needle lockstitch sewing machine includes: a pair of needles (9) that reciprocates in an up-down direction; a pair of loop catchers (40) that is arranged respectively corresponding to the pair of needles (9) and that catch loops of needle threads formed by the needles (9) by rotating about hook shafts (41) extending in the up-down direction; a lower shaft (20) that is disposed in front of the needles (9) and the loop catchers (40) in the cloth feeding direction and extends in the left-right direction and that rotates in conjunction with a main shaft (10) that drives the needles (9); and connecting shafts (30) that extend in the cloth feeding direction and are connected to the lower shaft (20) and the hook shafts (41) in a power transmittable manner to rotate. The loop catchers (40) are rotationally driven in conjunction with an up and down movement of the needles (9) as a rotational power of the lower shaft (20) is transmitted to the hook shafts (41) via the connecting shafts (30). Thus, it is possible to easily sew a tubular article with two rows of lockstitch seams.

Provided is a double-needle lockstitch sewing machine that can easily sew a fabric rolled into a tubular shape by two rows of lockstitch. The double-needle lockstitch sewing machine includes: a pair of needles (9) that reciprocates in an up-down direction; a pair of loop catchers (40) that is arranged respectively corresponding to the pair of needles (9) and that catch loops of needle threads formed by the needles (9) by rotating about hook shafts (41) extending in the up-down direction; a lower shaft (20) that is disposed in front of the needles (9) and the loop catchers (40) in the cloth feeding direction and extends in the left-right direction and that rotates in conjunction with a main shaft (10) that drives the needles (9); and connecting shafts (30) that extend in the cloth feeding direction and are connected to the lower shaft (20) and the hook shafts (41) in a power transmittable manner to rotate. The loop catchers (40) are rotationally driven in conjunction with an up and down movement of the needles (9) as a rotational power of the lower shaft (20) is transmitted to the hook shafts (41) via the connecting shafts (30). Thus, it is possible to easily sew a tubular article with two rows of lockstitch seams.

A sewing machine according to the present invention includes: an upper shaft that drives a needle and a balance; a lower shaft that drives a hook and a feed dog; an upper and lower shaft belt that synchronizes rotation of the upper shaft with rotation of the lower shaft; and an idler unit that pushes an idler into the upper and lower shaft belt to change a tension side belt length, in which the idler unit includes a transmission mechanism connected to the upper shaft or the lower shaft, and a rotating body mechanism provided with the idler and having a rotating body that rotates in synchronization with the upper shaft or the lower shaft by the transmission mechanism, and a pushing amount of the idler into the upper and lower shaft belt is changed according to rotation of the rotating body.

A sewing machine according to the present invention includes: an upper shaft that drives a needle and a balance; a lower shaft that drives a hook and a feed dog; an upper and lower shaft belt that synchronizes rotation of the upper shaft with rotation of the lower shaft; and an idler unit that pushes an idler into the upper and lower shaft belt to change a tension side belt length, in which the idler unit includes a transmission mechanism connected to the upper shaft or the lower shaft, and a rotating body mechanism provided with the idler and having a rotating body that rotates in synchronization with the upper shaft or the lower shaft by the transmission mechanism, and a pushing amount of the idler into the upper and lower shaft belt is changed according to rotation of the rotating body.

Provided is a double-needle lockstitch sewing machine that can easily sew a fabric rolled into a tubular shape by two rows of lockstitch. The double-needle lockstitch sewing machine includes: a pair of needles (9) that reciprocates in an up-down direction; a pair of loop catchers (40) that is arranged respectively corresponding to the pair of needles (9) and that catch loops of needle threads formed by the needles (9) by rotating about hook shafts (41) extending in the up-down direction; a lower shaft (20) that is disposed in front of the needles (9) and the loop catchers (40) in the cloth feeding direction and extends in the left-right direction and that rotates in conjunction with a main shaft (10) that drives the needles (9); and connecting shafts (30) that extend in the cloth feeding direction and are connected to the lower shaft (20) and the hook shafts (41) in a power transmittable manner to rotate. The loop catchers (40) are rotationally driven in conjunction with an up and down movement of the needles (9) as a rotational power of the lower shaft (20) is transmitted to the hook shafts (41) via the connecting shafts (30). Thus, it is possible to easily sew a tubular article with two rows of lockstitch seams.

Provided is a double-needle lockstitch sewing machine that can easily sew a fabric rolled into a tubular shape by two rows of lockstitch. The double-needle lockstitch sewing machine includes: a pair of needles (9) that reciprocates in an up-down direction; a pair of loop catchers (40) that is arranged respectively corresponding to the pair of needles (9) and that catch loops of needle threads formed by the needles (9) by rotating about hook shafts (41) extending in the up-down direction; a lower shaft (20) that is disposed in front of the needles (9) and the loop catchers (40) in the cloth feeding direction and extends in the left-right direction and that rotates in conjunction with a main shaft (10) that drives the needles (9); and connecting shafts (30) that extend in the cloth feeding direction and are connected to the lower shaft (20) and the hook shafts (41) in a power transmittable manner to rotate. The loop catchers (40) are rotationally driven in conjunction with an up and down movement of the needles (9) as a rotational power of the lower shaft (20) is transmitted to the hook shafts (41) via the connecting shafts (30). Thus, it is possible to easily sew a tubular article with two rows of lockstitch seams.

Embroidery and sewing machines can utilize rotary hooks to attach thread to materials. An adhesive joint configured to sever if the rotary hook becomes jammed prevents damage to the rest of the drive system. The severable joint is located between a sleeve and a drive shaft nearest the rotary hook to allow for easy removal and repair of the joint.