A rotary hook includes a bobbin case housing a lower thread bobbin, an inner rotary hook and an outer rotary hook. A needle drop hole is provided in an upper front surface of the inner rotary hook, and a recess is formed therein at a position deviated from the needle drop hole in a rotating direction of the outer rotary hook. The recess opens forward and upward and has a rear wall. The bobbin case provides with a thread take-up member for directing a lower thread, paid out from the lower thread bobbin, toward the recess. The lower thread paid out from the lower thread bobbin is passed through the recess via the thread take-up member and then directed to a needle hole of a needle plate provided above. With this arrangement, it is possible to structurally avoid occurrence of a hitch stitch caused by the lower thread.

A rotary hook includes a bobbin case housing a lower thread bobbin, an inner rotary hook and an outer rotary hook. A needle drop hole is provided in an upper front surface of the inner rotary hook, and a recess is formed therein at a position deviated from the needle drop hole in a rotating direction of the outer rotary hook. The recess opens forward and upward and has a rear wall. The bobbin case provides with a thread take-up member for directing a lower thread, paid out from the lower thread bobbin, toward the recess. The lower thread paid out from the lower thread bobbin is passed through the recess via the thread take-up member and then directed to a needle hole of a needle plate provided above. With this arrangement, it is possible to structurally avoid occurrence of a hitch stitch caused by the lower thread.

A needle plate has a needle hole and a guide hole communicating with the needle hole. The guide hole is located near a front side of a sewing machine and positionally deviated from an up-down movement trajectory of a sewing needle in a rotating direction of a rotary hook. The needle plate has a groove formed in front of the needle hole and extending from the guide hole in a direction opposite to the rotating direction of the rotary hook. While the groove is open upward and at its portion leading to the guide hole, the other portions of the groove are defined by a bottom surface and side walls. In a sewing operation, depending on a direction in which a member holding a sewing workpiece moves, the lower thread passes through the guide hole to be guided to the front of the needle hole via the groove.

A rotary hook includes a bobbin case housing a lower thread bobbin, an inner rotary hook and an outer rotary hook. A needle drop hole is provided in an upper front surface of the inner rotary hook, and a recess is formed therein at a position deviated from the needle drop hole in a rotating direction of the outer rotary hook. The recess opens forward and upward and has a rear wall. The bobbin case provides with a thread take-up member for directing a lower thread, paid out from the lower thread bobbin, toward the recess. The lower thread paid out from the lower thread bobbin is passed through the recess via the thread take-up member and then directed to a needle hole of a needle plate provided above. With this arrangement, it is possible to structurally avoid occurrence of a hitch stitch caused by the lower thread.

A rotary hook includes a bobbin case housing a lower thread bobbin, an inner rotary hook and an outer rotary hook. A needle drop hole is provided in an upper front surface of the inner rotary hook, and a recess is formed therein at a position deviated from the needle drop hole in a rotating direction of the outer rotary hook. The recess opens forward and upward and has a rear wall. The bobbin case provides with a thread take-up member for directing a lower thread, paid out from the lower thread bobbin, toward the recess. The lower thread paid out from the lower thread bobbin is passed through the recess via the thread take-up member and then directed to a needle hole of a needle plate provided above. With this arrangement, it is possible to structurally avoid occurrence of a hitch stitch caused by the lower thread.

A system and methods for stitching are disclosed. The system includes a first thread feeding mechanism configured to feed a continuous supply of a first thread, a second thread feeding mechanism configured to feed a continuous supply of a second thread, a plate separating the first thread feeding mechanism and the second thread feeding mechanism, and a knot tying mechanism configured to pass a bight of the first thread for at least one turn around a portion of the second thread and securing the bight around the second thread.