Abstract: A sewing machine includes: a needle rod being reciprocated vertically; tension discs sandwiching an upper thread; a feed mechanism transporting a sewing object in a vertical direction; a reciprocating mechanism reciprocating the needle rod laterally; an upper thread tension adjusting mechanism adjusting the tension discs; a feed amount adjusting mechanism adjusting a feed amount of the feed mechanism; a stitch width adjusting mechanism adjusting a stitch width of the reciprocating mechanism; and a control apparatus controlling the upper thread tension adjusting mechanism, the feed amount adjusting mechanism, and/or the stitch width adjusting mechanism. A common adjusting mechanism, being one of the feed amount adjusting mechanism and the stitch width adjusting mechanism, includes: a motor; an adjusting mechanism body being a tooth-missing gear and/or a cam; and a variation amount adjusting unit.

Abstract: An apparatus for lifting the presser foot of an embroidery machine includes an arm having an upper shaft providing a driving force, a presser foot driving cam mounted on the upper shaft, a transmission member coupled to the presser foot driving cam and making an oscillating motion, a presser foot driving lever connected to the transmission member and pivoting around a predetermined pivoting point thereof in a vertical direction, a presser foot driving block reciprocating along a needle bar guide shaft according to an amount that the presser foot driving lever is pivoted and moving the presser foot in a vertical direction, and a presser foot height adjustor, displacing the pivoting point of the presser foot driving lever to adjust a height of the presser foot.

Abstract: The sewing machine includes a presser foot that is lowered to press a workpiece cloth; a presser foot lifting lever operating the presser foot; a thread tension mechanism including a thread tension regulator capable of adjusting the thread tension of a needle thread and opening the thread tension regulator based on the lifting operation of the presser foot lifting lever; and a thread guide groove guiding the needle thread at least to the thread tension mechanism, upon carrying out the thread hooking work. The sewing machine further includes a detector detecting a lifting operation of the presser foot lifting lever; a covering member which is movable between a closed position where the covering member covers at least a part of the thread guide groove and an opened position where the covering member opens the thread guide groove. The covering member is moved to the closed position when the presser foot is in a lowered state.

Abstract: A presser foot control system for a sewing station for sewing heavy gauge or thick materials includes an actuator for selectively applying and relieving an additional compression force to the presser foot of the sewing station for compressing and feeding the material being sewn to enable engagement and pickup of the threads carried by the needle by a looper of the sewing station.

Abstract: A stop lever fixing lever supported at a bed body of a sewing machine has one end to be contacted by a projection of a pattern wheel. A connecting member has one end connected to the other end of the stop lever fixing lever. A first presser bar lifter has one end connected to the other end of the connecting member. A second presser bar lifter has one end defining an operation arm positioned at a lifting position and has a folded projection provided with a hole. A stepped screw having a knurled thumb at the peripheral surface thereof is rotatably inserted in the hole of the folded projection edge with a small diameter screw portion at the tip end thereof. A lever shifting member is screwed into the small diameter screw portion at the folded projection edge. A presser bar lifter cam is disposed along a cutting axis and has a projection.

Abstract: A lower thread tension device is provided in association with adjustment of an upper thread tension device in such a manner that when the tension of the upper thread tension device is strong within an adjusting range, the lower thread tension is adjusted strongly, and when the tension of the upper thread tension device is weak within the adjusting range, the lower thread tension is adjusted weakly. The upper and lower thread tension device includes a dial for adjusting an upper thread tension, a potentiometer connected to the dial, and an electromagnet with an actuator acting on the lower thread to adjust its tension in response to a signal received from the potentiometer due to rotation of the dial. The upper and lower thread tension device includes a dial for adjusting an upper thread tension, a potentiometer connected to the dial, and an electromagnet with an actuator acting on the lower thread to adjust its tension in response to a signal received from the potentiometer due to rotation of the dial.

Abstract: In a double-needle lock-stitch sewing machine, an assembly for arresting threads being drawn from the needles by an uptake stroke of a thread lever, thereby ensuring predetermined lengths of thread at the needles for an ensuing stitch, comprises a spring-loaded clamp disposed between the sewing lever and the needles. The clamp is periodically actuatable via a system of levers in the sewing-machine head by a cam mounted on the sewing-machine base and cooperating with a radial lug on a shaft driving a rotary thread gripper and bobbin holder. A spring-loaded plate engaging a pair of thread-tension control disks is pivotable by the lever system to release the disks upon actuation of the clamp. The clamp is particularly useful in controlling the length of a leading thread portion prior to beginning a sewing seam.

Abstract: A mechanism is disclosed in which the main driving mechanism of a sewing machine is harnessed simultaneously to actuate a thread wiper and a tension release mechanism for the sewing machine. Operation of the mechanism may be initiated by a solenoid which may be advantageously small in size and power since the solenoid does not supply any of the driving force incident to the operation of the thread wiper or tension release mechanisms.