A sewing machine that suppresses sewing defects is provided. The sewing machine includes: a sewing needing, held by a needle bar and moving back and forth while holding an upper thread: a shuttle, configured to hold a bobbin which is housed in a bobbin case and around which a lower thread is wound, and cooperating with the sewing needle to form a seam; a presser foot member, configured to press a to-be-sewn article at a sewing position directly below the sewing needle: a pressure adjustment portion, adjusting pressure applied to the to-be-sewn article by the presser foot member; a feeding mechanism, where endless feeding belts for feeding the to-be-sewn article from the sewing position to a first direction are disposed on two sides of a second direction orthogonal to a first direction with respect to the sewing position, the feeding mechanism is provided with a belt drive portion, and the belt drive portion independently drives the feeding belts on one side of the second direction with respect to the sewing position and the feeding belts on another side of the second direction with respect to the sewing position; and a control portion, configured to control the pressure adjustment portion to make a pressure of the presser foot member be corresponding to a difference between a feeding amount of the feeding belts on one side of the second direction with respect to the sewing position and a feeding amount of the feeding belts on another side of the second direction with respect to the sewing position.

A sewing machine includes: a sewing needle; a shuttle, cooperating with the sewing needle to form a seam; a pressing member, pressing a sewing object disposed at a sewing position immediately below the sewing needle; a feed mechanism, in which endless feed belts feeding the sewing object disposed at the sewing position from the sewing position along a first direction are disposed on two sides with respect to the sewing position in a second direction orthogonal to the first direction, and in which a belt drive part is provided; a needle drive part, provided separately from the belt drive part, and moving the sewing needle in the first direction; and a control part, exerting control so that the belt drive part and the needle drive part operate independently.

A sewing machine includes: a sewing needle; a shuttle, cooperating with the sewing needle to form a seam; a pressing member, pressing a sewing object disposed at a sewing position immediately below the sewing needle; a feed mechanism, in which endless feed belts feeding the sewing object disposed at the sewing position from the sewing position along a first direction are disposed on two sides with respect to the sewing position in a second direction orthogonal to the first direction, and in which a belt drive part is provided; a needle drive part, provided separately from the belt drive part, and moving the sewing needle in the first direction; and a control part, exerting control so that the belt drive part and the needle drive part operate independently.

A knee operated lifting mechanism for a presser foot of a sewing machine is fixed on a body of the sewing machine, the body is provided with a presser-foot shaft, the knee operated lifting mechanism is drivingly connected to the presser-foot shaft, so as to consequently drive the presser foot to move up and down. The knee operated lifting mechanism includes a knee pushing device, a cable and a rotary member. The knee pushing device includes a knee pushing plate to be operated by a user. The cable is drivingly connected to the knee pushing plate to control the rotation of a drive shaft and the rotation of the presser-foot shaft as well, which consequently controls the upward and downward motion of the presser foot, and thus considerably simplifying the structure of the knee operated lifting mechanism.

A knee operated lifting mechanism for a presser foot of a sewing machine is fixed on a body of the sewing machine, the body is provided with a presser-foot shaft, the knee operated lifting mechanism is drivingly connected to the presser-foot shaft, so as to consequently drive the presser foot to move up and down. The knee operated lifting mechanism includes a knee pushing device, a cable and a rotary member. The knee pushing device includes a knee pushing plate to be operated by a user. The cable is drivingly connected to the knee pushing plate to control the rotation of a drive shaft and the rotation of the presser-foot shaft as well, which consequently controls the upward and downward motion of the presser foot, and thus considerably simplifying the structure of the knee operated lifting mechanism.

A kit for adding or replacing an automated upper walking foot stepping height adjustment to a sewing machine, the kit includes a mounting assembly including an actuator bracket, an actuator coupled to the actuator bracket, a drive assembly, and a needle drive assembly. The actuator includes an actuator shaft that extends and retracts. The drive assembly includes a drive shaft, a drive arm coupled to the drive shaft and the actuator shaft, and a guide coupled to the drive shaft. The needle drive assembly includes a variable drive crank coupled to the guide and configured to couple to a needle drive shaft of a sewing machine. Selectively extending and retracting the actuator shaft selectively adjusts a stepping height of an upper walking foot.

A kit for adding or replacing an automated upper walking foot stepping height adjustment to a sewing machine, the kit includes a mounting assembly including an actuator bracket, an actuator coupled to the actuator bracket, a drive assembly, and a needle drive assembly. The actuator includes an actuator shaft that extends and retracts. The drive assembly includes a drive shaft, a drive arm coupled to the drive shaft and the actuator shaft, and a guide coupled to the drive shaft. The needle drive assembly includes a variable drive crank coupled to the guide and configured to couple to a needle drive shaft of a sewing machine. Selectively extending and retracting the actuator shaft selectively adjusts a stepping height of an upper walking foot.

A sewing machine moves a presser foot up and down through a presser-bar lifting lever to depress a cloth. The lever is moved down by a stepping motor at a constant move-down amount. A compression spring is present between the stepping motor and the presser foot. The compression spring is compressed by some of the constant move-down amount of the lever, and applies, to the presser foot, pushing force canceling repulsive force from the depressed cloth. The move-down amount of the presser foot is detected by an encoder, and a thickness of the cloth is calculated by a cloth-thickness calculator. The cloth-thickness calculator performs calculation based on the move-down amounts at two timings in a time period at which the presser foot depresses the cloth and attempts to further move down.

A sewing machine moves a presser foot up and down through a presser-bar lifting lever to depress a cloth. The lever is moved down by a stepping motor at a constant move-down amount. A compression spring is present between the stepping motor and the presser foot. The compression spring is compressed by some of the constant move-down amount of the lever, and applies, to the presser foot, pushing force canceling repulsive force from the depressed cloth. The move-down amount of the presser foot is detected by an encoder, and a thickness of the cloth is calculated by a cloth-thickness calculator. The cloth-thickness calculator performs calculation based on the move-down amounts at two timings in a time period at which the presser foot depresses the cloth and attempts to further move down.

A presser foot position retainer includes a presser foot and a restricting member. The presser foot is swingably attachable to a presser holder of a sewing machine. The presser foot includes a shaft extending in an axial direction, a restricted portion, and a pressing surface configured to press a workpiece. The restricting member includes a restricting portion capable of contacting the restricted portion. The restricting member is attachable to the presser holder. The restricting member is configured to move between a first position and a second position by a user operation. When the restricting member is located at the second position, the restricting portion is in contact with the restricted portion to limit a swingable range within which the presser foot attached to the presser holder is swingable about the shaft to less than that when the restricting member is located at the first position.