Abstract: The disclosure improves the quality of seams in sewing using a sewing machine, and includes: a holder holding fabric; a driver being detachable from a bed of a sewing machine and driving the holder along an upper surface of the bed; a position detector detecting a position of a sewing needle of the sewing machine in an up-down direction; and a controller controlling driving of the holder, which is performed by the driver, based on a detection result of the position detector.

Abstract: A sewing machine external unit includes: a holder holding fabric; a driver being detachable from a bed of a sewing machine and driving the holder along an upper surface of the bed; a pressing member moving in an up-down direction according to movement of a sewing needle in the up-down direction, pressing the fabric while the sewing needle is stuck in the fabric, and rising together with the sewing needle in response to the sewing needle coming out of the fabric and rising; a position detector detecting a position of the pressing member in the up-down direction; a signal output part outputting a signal to the sewing machine; and a controller outputting a needle drive signal for driving the sewing needle from the signal output part to the sewing machine, and controlling driving of the holder and/or the sewing needle based on a detection result of the position detector.

Abstract: A sewing machine includes a feed mechanism which feeds a workpiece by a feed dog partially protruding out upward from an upper surface of a throat plate and moving along a predetermined feeding direction; a presser foot which presses the workpiece on the upper surface of the throat plate from above; a feed guide which has an abutting surface along the feeding direction and guides feeding of the workpiece; and a control device. The feed mechanism includes a lateral feed mechanism which adds a moving component in a direction along the upper surface of the throat plate and orthogonal to the predetermined feeding direction, to the feed dog. The control device controls the feed mechanism to feed the workpiece by adding a moving component to a side of the abutting surface of the feed guide by the lateral feed mechanism, in addition to the feeding along the regulated feeding direction.

Abstract: A sewing machine includes a movement amount detector which is configured to detect a movement amount of a workpiece, a motor which is a rotation driving source of an upper shaft configured to provide a vertical motion to a needle bar, and a control device which is configured to control the motor based on detection of the movement amount detector to maintain a constant stitch length. The movement amount detector is supported to be capable of being raised and lowered around a stitch position. The sewing machine includes a pressing unit configured to provide an upward elastic force such that a detection surface of the movement amount detector protrudes from an upper surface of a throat plate.

Abstract: A sewing machine, in which a presser foot and a throat plate are detachable, includes a feed dog bracket, a feeding dog and a mounting portion. The feed dog bracket is driven according to a transfer direction of a fabric. The feeding dog transfers the fabric on the throat plate. The mounting portion detachably mounts the feeding dog on the feed dog bracket. The feeding dog includes a cam portion which is mounted on the mounting portion. The cam portion includes first, second and third cam surfaces. The first cam surface has a surface-contact with a first receiving surface of the mounting portion. The second cam surface has a line-contact with an end portion of a second receiving surface of the mounting portion. The third cam surface is pressed by a pressing member of the mounting portion.

Abstract: A sewing machine includes a movement amount detector which is configured to detect a movement amount of a workpiece, a motor which is a rotation driving source of an upper shaft configured to provide a vertical motion to a needle bar, and a control device which is configured to control the motor based on detection of the movement amount detector to maintain a constant stitch length. The movement amount detector is supported to be capable of being raised and lowered around a stitch position. The sewing machine includes a pressing unit configured to provide an upward elastic force such that a detection surface of the movement amount detector protrudes from an upper surface of a throat plate.

Abstract: A sewing machine includes a feed mechanism which feeds a workpiece by a feed dog partially protruding out upward from an upper surface of a throat plate and moving along a predetermined feeding direction; a presser foot which presses the workpiece on the upper surface of the throat plate from above; a feed guide which has an abutting surface along the feeding direction and guides feeding of the workpiece; and a control device. The feed mechanism includes a lateral feed mechanism which adds a moving component in a direction along the upper surface of the throat plate and orthogonal to the predetermined feeding direction, to the feed dog. The control device controls the feed mechanism to feed the workpiece by adding a moving component to a side of the abutting surface of the feed guide by the lateral feed mechanism, in addition to the feeding along the regulated feeding direction.

Abstract: A throat plate switching mechanism includes a first throat plate and a second throat plate. The first throat plate is formed with a first needle hole having an elongated hole shape at a stitch point. The second throat plate is formed with a second needle hole. A width of the second needle hole is narrower than a width of the first needle hole. The second throat plate is equipped in the first throat plate such that the second throat plate is switched into a use position at which the second needle hole overlaps the first needle hole, and a retreated position at which the second throat plate does not cover the first needle hole.

Abstract: A throat plate switching mechanism includes a first throat plate and a second throat plate. The first throat plate is formed with a first needle hole having an elongated hole shape at a stitch point. The second throat plate is formed with a second needle hole. A width of the second needle hole is narrower than a width of the first needle hole. The second throat plate is equipped in the first throat plate such that the second throat plate is switched into a use position at which the second needle hole overlaps the first needle hole, and a retreated position at which the second throat plate does not cover the first needle hole.

Abstract: A sewing machine, in which a presser foot and a throat plate are detachable, includes a feed dog bracket, a feeding dog and a mounting portion. The feed dog bracket is driven according to a transfer direction of a fabric. The feeding dog transfers the fabric on the throat plate. The mounting portion detachably mounts the feeding dog on the feed dog bracket. The feeding dog includes a cam portion which is mounted on the mounting portion. The cam portion includes first, second and third cam surfaces. The first cam surface has a surface-contact with a first receiving surface of the mounting portion. The second cam surface has a line-contact with an end portion of a second receiving surface of the mounting portion. The third cam surface is pressed by a pressing member of the mounting portion.

Abstract: There are provided an upper shaft clutch mechanism 140, a bobbin 22 including a slit 39, a horizontal holder 4 including an inner holder 18 and a blade tip 42, a bobbin driving member 11, bobbin driving member moving means 94 for moving the bobbin driving member 11 to freely advance or retreat between two positions having a separating position and a connecting position, a thread holding and catching member 48 including an upper thread holding portion 59, an upper thread engaging portion 60 and a thread position regulating portion 58 which are always set in a retreat position and are set in an entry position during a thread winding operation, thread holding and catching member moving means 53 for moving the thread holding and catching member 48 to freely advance or retreat between two positions having a retreat position and an entry position, and a thread winding operation control portion 193 for controlling the operation of each portion during the thread winding operation.

Abstract: There are provided an upper shaft clutch mechanism 140, a bobbin 22 including a slit 39, a horizontal holder 4 including an inner holder 18 and a blade tip 42, a bobbin driving member 11, bobbin driving member moving means 94 for moving the bobbin driving member 11 to freely advance or retreat between two positions having a separating position and a connecting position, a thread holding and catching member 48 including an upper thread holding portion 59, an upper thread engaging portion 60 and a thread position regulating portion 58 which are always set in a retreat position and are set in an entry position during a thread winding operation, thread holding and catching member moving means 53 for moving the thread holding and catching member 48 to freely advance or retreat between two positions having a retreat position and an entry position, and a thread winding operation control portion 193 for controlling the operation of each portion during the thread winding operation.