An upper feed device includes a main body portion configured to be mounted to a presser bar of a sewing machine, and a presser foot configured to be detachably mounted to the main body portion. The main body portion has an upper feed dog, a first mounting portion, and a second mounting portion. The first mounting portion has a first groove opening downward, and the second mounting portion has a second groove opening downward. The presser foot has a presser plate, a first opposing portion, a second opposing portion, a first pin, a first protruding portion, a second pin, and a second protruding portion. An opening is formed in the presser plate. The first pin is configured to rotatably fit into the first groove. The second pin is configured to rotatably fit into the second groove.

An upper feed device includes a main body portion configured to be mounted to a presser bar of a sewing machine, and a presser foot configured to be detachably mounted to the main body portion. The main body portion has an upper feed dog, a first mounting portion, and a second mounting portion. The first mounting portion has a first groove opening downward, and the second mounting portion has a second groove opening downward. The presser foot has a presser plate, a first opposing portion, a second opposing portion, a first pin, a first protruding portion, a second pin, and a second protruding portion. An opening is formed in the presser plate. The first pin is configured to rotatably fit into the first groove. The second pin is configured to rotatably fit into the second groove.

Provided is a sewing machine capable of positioning feed dogs with a sufficient distance below the upper surface of a throat plate when the feed dogs are retracted. Feed dogs 3 protrude and retract from a throat plate 1. A horizontal feed drive unit 8 converts the rotation of a drive shaft 7 into a reciprocating motion in the horizontal direction and transmits the horizontal reciprocating motion to the feed dogs 3. A vertical drive unit 9 converts the rotation of the drive shaft 7 into a reciprocating motion in the vertical direction and transmits the vertical reciprocating motion to the feed dogs 3. A vertical position changing part moves turn-back points P at both ends of a forward path and a return path when the feed dogs 3 reciprocate in the horizontal direction below the throat plate 1.

Provided is a sewing machine capable of positioning feed dogs with a sufficient distance below the upper surface of a throat plate when the feed dogs are retracted. Feed dogs 3 protrude and retract from a throat plate 1. A horizontal feed drive unit 8 converts the rotation of a drive shaft 7 into a reciprocating motion in the horizontal direction and transmits the horizontal reciprocating motion to the feed dogs 3. A vertical drive unit 9 converts the rotation of the drive shaft 7 into a reciprocating motion in the vertical direction and transmits the vertical reciprocating motion to the feed dogs 3. A vertical position changing part moves turn-back points P at both ends of a forward path and a return path when the feed dogs 3 reciprocate in the horizontal direction below the throat plate 1.

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.

Provided is a sewing machine capable of positioning feed dogs with a sufficient distance below the upper surface of a throat plate when the feed dogs are retracted. Feed dogs 3 protrude and retract from a throat plate 1. A horizontal feed drive unit 8 converts the rotation of a drive shaft 7 into a reciprocating motion in the horizontal direction and transmits the horizontal reciprocating motion to the feed dogs 3. A vertical drive unit 9 converts the rotation of the drive shaft 7 into a reciprocating motion in the vertical direction and transmits the vertical reciprocating motion to the feed dogs 3. A vertical position changing part moves turn-back points P at both ends of a forward path and a return path when the feed dogs 3 reciprocate in the horizontal direction below the throat plate 1.

Provided is a sewing machine capable of positioning feed dogs with a sufficient distance below the upper surface of a throat plate when the feed dogs are retracted. Feed dogs 3 protrude and retract from a throat plate 1. A horizontal feed drive unit 8 converts the rotation of a drive shaft 7 into a reciprocating motion in the horizontal direction and transmits the horizontal reciprocating motion to the feed dogs 3. A vertical drive unit 9 converts the rotation of the drive shaft 7 into a reciprocating motion in the vertical direction and transmits the vertical reciprocating motion to the feed dogs 3. A vertical position changing part moves turn-back points P at both ends of a forward path and a return path when the feed dogs 3 reciprocate in the horizontal direction below the throat plate 1.

An upper feed device includes a main body portion configured to be mounted to a presser bar of a sewing machine, and a presser foot configured to be detachably mounted to the main body portion. The main body portion has an upper feed dog, a first mounting portion, and a second mounting portion. The first mounting portion has a first groove opening downward, and the second mounting portion has a second groove opening downward. The presser foot has a presser plate, a first opposing portion, a second opposing portion, a first pin, a first protruding portion, a second pin, and a second protruding portion. An opening is formed in the presser plate. The first pin is configured to rotatably fit into the first groove. The second pin is configured to rotatably fit into the second groove.

An upper feed device includes a main body portion configured to be mounted to a presser bar of a sewing machine, and a presser foot configured to be detachably mounted to the main body portion. The main body portion has an upper feed dog, a first mounting portion, and a second mounting portion. The first mounting portion has a first groove opening downward, and the second mounting portion has a second groove opening downward. The presser foot has a presser plate, a first opposing portion, a second opposing portion, a first pin, a first protruding portion, a second pin, and a second protruding portion. An opening is formed in the presser plate. The first pin is configured to rotatably fit into the first groove. The second pin is configured to rotatably fit into the second groove.

A sewing machine includes: a needle vertical movement mechanism which moves a sewing needle; a moving mechanism which holds a workpiece by a holding frame; an inner presser-foot device which moves an inner presser foot on an upper side of the workpiece held by the holding frame; a control device which controls the moving mechanism based on sewing data in which stitch positions are defined in order in a series of sewing; and a height detector which detects a height of the inner presser foot. The control device lowers the inner presser foot to an upper surface of the workpiece held by the holding frame, detects the height of the inner presser foot by the height detector, and determines suitability of a thickness of the workpiece, at one or plural stitch positions defined in the sewing data before starting the sewing in accordance with the sewing data.