A sewing system comprises a sewing machine, a camera that captures an image of a reference position for sewing, a robot arm that holds the sewing machine and the camera, and a controller. The controller controls operations of forming a first stitch position that results from stitching of the sewing machine, and forming a second stitch position that results from stitching of the sewing machine after rotating the sewing machine at a prescribed angle about a rotation axis that passes through a needle center position stored by the controller. The controller further performs calibration processing that calibrates the needle center position stored by the controller, based on each position of the first stitch position and the second stitch position within image capture ranges of capture images that are obtained by capturing images of the first stitch position and the second stitch position using the camera.

A sewing machine in which a base configured to support a throat plate, a shuttle or a looper, and an input shaft for a stitching operation to the shuttle or the looper with respect to a bed portion of a frame is supported to be movable along a direction of approaching or separating from a sewing needle is provided. The sewing machine includes a connecting member which changes to any one of a state in which the input shaft and a transmission shaft are aligned in the same straight line to be in a torque transmission state and a state in which the input shaft moves together with the base with respect to the transmission shaft, between the input shaft on the base side and the transmission shaft which transmits power to the input shaft.

A compressed air supplying device of a sewing machine includes an air pump unit including a piston; a piston driving spring applying biasing force to the piston in an exhaust air direction which is a direction in which the air pump unit exhausts air for driving the piston in the exhaust air direction by the biasing force; a lever making the air pump unit perform intake air movements; and an operating force transmitting mechanism transmitting operating force of the lever to the piston for actuating the piston only in an intake air direction which is a direction in which the air pump unit intakes air against the biasing force of the piston driving spring by the operating force.

A compressed air supplying device of a sewing machine includes an air pump unit including a piston; a piston driving spring applying biasing force to the piston in an exhaust air direction which is a direction in which the air pump unit exhausts air for driving the piston in the exhaust air direction by the biasing force; a lever making the air pump unit perform intake air movements; and an operating force transmitting mechanism transmitting operating force of the lever to the piston for actuating the piston only in an intake air direction which is a direction in which the air pump unit intakes air against the biasing force of the piston driving spring by the operating force.

In a sewing machine equipped with a needle threading device, a thread holding tool includes: a thread holding surface part that guides and holds a thread; a thread pressing member that presses and sandwiches together with the thread holding surface part the thread; and a thread detachment preventing part that is provided to cross the thread which is sandwiched between the thread pressing member and the thread holding surface part. When passing the thread through the needle hole, a thread detachment preventing part regulates the thread so that the thread, which is sandwiched between the thread holding surface part and the thread pressing member of the thread holding tool, passes in a predetermined direction without deviating from a thread holding state.

A thread inserting device includes a guide pin having a thread capture portion at its tip for capturing a thread; a holder that fixedly holds the guide pin; a main body (first and second main bodies) slidably mounting the holder; and a thread cutting portion provided to the main body for cutting the thread to a length equal to or smaller than the protrusion of the thread capture portion from a thread captured position on a thread tip 6a side after the thread is captured by the thread capture portion. By shifting the holder, the thread capture portion is protruded to a predetermined length from the main body, and the thread cut to a predetermined length by the thread cutting portion is inserted into the thread inserting hole.

A thread inserting device includes a guide pin having a thread capture portion at its tip for capturing a thread; a holder that fixedly holds the guide pin; a main body (first and second main bodies) slidably mounting the holder; and a thread cutting portion provided to the main body for cutting the thread to a length equal to or smaller than the protrusion of the thread capture portion from a thread captured position on a thread tip 6a side after the thread is captured by the thread capture portion. By shifting the holder, the thread capture portion is protruded to a predetermined length from the main body, and the thread cut to a predetermined length by the thread cutting portion is inserted into the thread inserting hole.

A sewing machine equipped with a needle threading device, includes: a needle bar supporting frame body on which there is mounted a needle bar that is mounted with a needle having a needle hole; a needle threading shaft that is disposed on the needle bar supporting frame body and is supported vertically movably and also turnably in a peripheral direction; a thread pressing part and a thread holding tool that are provided at a lower end of the needle threading shaft and that hold in a tensioned state a thread opposite the needle hole; and a needle threading tool that is provided at a lower end of the needle threading shaft and that has a hook which reciprocates through the needle hole to pass the thread through the needle hole, wherein the thread holding tool comprises a thread holding surface part that guides and holds the thread.

A overlock sewing machine includes a switch limiting arm rockable integrally with a main shaft fixing operating arm and an arm including arms which are actuated by operating a threading switching knob to engage with the switch limiting arm to rock a rocking lever portion and being engageable with a slide plate to move the position of the slide plate to a sewing executable position upon operating the threading switching knob to the sewing executing position side.

A overlock sewing machine includes a switch limiting arm rockable integrally with a main shaft fixing operating arm and an arm including arms which are actuated by operating a threading switching knob to engage with the switch limiting arm to rock a rocking lever portion and being engageable with a slide plate to move the position of the slide plate to a sewing executable position upon operating the threading switching knob to the sewing executing position side.