A method of manufacturing leggings having a leg portion and a waistband portion, using a fabric is disclosed. The method includes brushing an outside surface of the fabric once to form a single-brushed surface. The method includes brushing an inside surface of the fabric multiple times to form a multiple-brushed surface. The method includes cutting the fabric into a plurality of pieces for the leg portion and a plurality of pieces for the waistband portion and sewing the pieces together, the waistband portion having a top edge and a bottom edge, the top edge of the waistband portion being narrower than the bottom edge of the waistband portion, the single-brushed surface of the fabric forming an inside legging surface configured to contact a wearer, and the multiple-brushed surface of the fabric forming an outside legging surface. The method includes sewing an elastic band to the top edge of the waistband.

A sewing machine that includes a sewing bed on which a plurality of cloth pieces are placed in a manner of being overlaid on each other; a felting needle; a woolen yarn guide provided at a lower end of a safety cover for covering the felting needle; and a device configured to raise and lower the felting needle toward the plurality of overlaid cloth pieces, and the woolen yarn guide is configured to guide a woolen yarn from a bobbin or a woolen yarn ball to a sewing location, and the device is configured to raise and lower the felting needle so that needle felting in which the felting needle is thrusted into the plurality of cloth pieces and the woolen yarn is performed, and thereby the plurality of cloth pieces are sewn together.

A sewing machine of the present embodiment comprises a movement amount detector which detects a movement amount of fabric, a sewing machine motor serving as a rotary drive source of an upper shaft which applies vertical movement to a needle bar, a shaft angle detector which detects a shaft angle of an output shaft of the upper shaft or the sewing machine motor, and a controller which controls the sewing machine motor based on the detection of the movement amount detector and performs controls of maintaining a constant stitch length. The controller performs controls of maintaining the constant stitch length, by a movement amount of the fabric detected by the movement amount detector in a shaft angle section where a sewing needle is not stuck into a cloth, based on the detection by the shaft angle detector.

A sewing machine of the present embodiment comprises a movement amount detector which detects a movement amount of fabric, a sewing machine motor serving as a rotary drive source of an upper shaft which applies vertical movement to a needle bar, a shaft angle detector which detects a shaft angle of an output shaft of the upper shaft or the sewing machine motor, and a controller which controls the sewing machine motor based on the detection of the movement amount detector and performs controls of maintaining a constant stitch length. The controller performs controls of maintaining the constant stitch length, by a movement amount of the fabric detected by the movement amount detector in a shaft angle section where a sewing needle is not stuck into a cloth, based on the detection by the shaft angle detector.

While feeding an upholstery member, a sewing needle is reciprocated to form needle receiving holes, and an upper thread is passed through each needle receiving hole, caused to cross a lower thread, and pulled out of the needle receiving hole. The sewing cycle is repeatedly performed to form a stitch, so that stitches form a stitch line in a surface sheet. A direction of a force, which is generated by applying tension to the lower thread and which acts to rotate thread ends of a pair of adjacent stitches in each needle receiving hole about a crossing part of the upper thread and the lower thread, is defined as a rotation direction. The sewing needle is rotated in a direction opposite to the rotation direction to incline a diagonal line of the quadrangular shape forming the cross section relative to the feeding direction of the upholstery member.

While feeding an upholstery member, a sewing needle is reciprocated to form needle receiving holes, and an upper thread is passed through each needle receiving hole, caused to cross a lower thread, and pulled out of the needle receiving hole. The sewing cycle is repeatedly performed to form a stitch, so that stitches form a stitch line in a surface sheet. A direction of a force, which is generated by applying tension to the lower thread and which acts to rotate thread ends of a pair of adjacent stitches in each needle receiving hole about a crossing part of the upper thread and the lower thread, is defined as a rotation direction. The sewing needle is rotated in a direction opposite to the rotation direction to incline a diagonal line of the quadrangular shape forming the cross section relative to the feeding direction of the upholstery member.

The present invention relates to an airbag cushion and an airbag system including the same, and particularly to an airbag cushion, including: at least one fabric; and seam parts connecting the fabric, wherein deviation of upper seam thread length per a unit length of the fabric between the first seam part sewed in forward direction and the second seam part sewed in reverse direction in the seam parts is 15% or less, a method of preparing the same, and an airbag system including the same. The airbag cushion of the present invention is superior in working stability and unfolding performance because of the optimized properties of the seam parts, provides superior shape stability and air-tight effect at the same time, and can protect a passenger by minimizing the shock given to the passenger.

The present invention relates to an airbag cushion and an airbag system including the same, and particularly to an airbag cushion, including: at least one fabric; and seam parts connecting the fabric, wherein deviation of upper seam thread length per a unit length of the fabric between the first seam part sewed in forward direction and the second seam part sewed in reverse direction in the seam parts is 15% or less, a method of preparing the same, and an airbag system including the same. The airbag cushion of the present invention is superior in working stability and unfolding performance because of the optimized properties of the seam parts, provides superior shape stability and air-tight effect at the same time, and can protect a passenger by minimizing the shock given to the passenger.

A variable timing system for a sewing machine is provided comprising a shuttle hook having a hook tip, a first helical gear mounted on the shuttle hook, a lower shaft configured to rotate the shuttle hook in synchronization with a needle bar, and a second helical gear mounted on the lower shaft and capable of engaging with the first helical gear. In accordance with embodiments, at least one of the helical gears is axially movable. The variable timing system may comprise a control device configured to generate a control signal representative of a current sewing situation. A drive force mechanism may receive the control signal and in response, transmit axial movement to the axially moveable helical gear to move the gear into proper position relative to a threaded needle of the sewing machine.