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.

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 includes an upper shaft rotatable so as to drive a needle bar, a lower shaft rotatable so as to drive a hook, an upper-shaft pulley attached to the upper shaft, a lower-shaft pulley attached to the lower shaft, a belt linking the upper-shaft pulley and the lower-shaft pulley, and synchronizing a rotation of the upper-shaft pulley and a rotation of the lower-shaft pulley with each other, a belt adjusting mechanism contacting the belt and changing a belt length at a tensioned side at which the belt is drawn, and a tensioner tensioning the belt in accordance with the change in the belt length of the belt at the tensioned side.

A sewing machine includes an upper shaft rotatable so as to drive a needle bar, a lower shaft rotatable so as to drive a hook, an upper-shaft pulley attached to the upper shaft, a lower-shaft pulley attached to the lower shaft, a belt linking the upper-shaft pulley and the lower-shaft pulley, and synchronizing a rotation of the upper-shaft pulley and a rotation of the lower-shaft pulley with each other, a belt adjusting mechanism contacting the belt and changing a belt length at a tensioned side at which the belt is drawn, and a tensioner tensioning the belt in accordance with the change in the belt length of the belt at the tensioned side.