Disclosed is an ornamental chain stitching head, including: an upper head assembly, the upper head assembly controls movement of a needle bar and a walking foot mechanism; a walking foot eccentric configured to allow adjustment of a foot lift while a stitch length eccentric is configured to allow for adjustment of both a walking foot and a needle bar advancement via regulation of a rock frame the determines a length of a stitch created by the ornamental chain stitching head; a lower head assembly; and a needle bar cam assembly that drives rotation of the needle bar during each stitch cycle of the ornamental chain stitching head to achieve desired stitch patterns, the needle bar cam assembly is driven directly by an upper shaft through a pair of gears that reduce the needle bar cam assembly speed according to a size ratio of the pair of gears.

Disclosed is an ornamental chain stitching head, including: an upper head assembly, the upper head assembly controls movement of a needle bar and a walking foot mechanism; a walking foot eccentric configured to allow adjustment of a foot lift while a stitch length eccentric is configured to allow for adjustment of both a walking foot and a needle bar advancement via regulation of a rock frame the determines a length of a stitch created by the ornamental chain stitching head; a lower head assembly; and a needle bar cam assembly that drives rotation of the needle bar during each stitch cycle of the ornamental chain stitching head to achieve desired stitch patterns, the needle bar cam assembly is driven directly by an upper shaft through a pair of gears that reduce the needle bar cam assembly speed according to a size ratio of the pair of gears.

A sewing machine comprises a crank shaft, a first drive shaft, a second drive shaft, a needle assembly, a presser foot, and an upper walking foot. A first crank arm assembly is connected to the crank shaft to the first drive shaft. A first linkage assembly is connected to the first drive shaft to the needle assembly. A second crank arm assembly is connected to the first drive shaft to the second drive shaft. A second linkage assembly is connected to the second drive shaft to the presser foot and the upper walking foot. The second linkage assembly is configured to cause out-of-phase reciprocatory movement of the presser foot and the upper walking foot. The second crank arm assembly has a variable length that is selectably adjustable by an operator to yield at least first and second different stepping heights of the upper walking foot.

A sewing machine comprises a crank shaft, a first drive shaft, a second drive shaft, a needle assembly, a presser foot, and an upper walking foot. A first crank arm assembly is connected to the crank shaft to the first drive shaft. A first linkage assembly is connected to the first drive shaft to the needle assembly. A second crank arm assembly is connected to the first drive shaft to the second drive shaft. A second linkage assembly is connected to the second drive shaft to the presser foot and the upper walking foot. The second linkage assembly is configured to cause out-of-phase reciprocatory movement of the presser foot and the upper walking foot. The second crank arm assembly has a variable length that is selectably adjustable by an operator to yield at least first and second different stepping heights of the upper walking foot.

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 presser foot vertical drive device includes an upper shaft configured to vertically drive a needle, a presser foot drive cam fixed to the upper shaft, a presser foot urged downward over a needle plate, a cam follower configured to be vertically driven in contact with the presser foot drive cam, and a link configured to transmit the vertical drive of the cam follower to the presser foot. The presser foot drive cam includes a plurality of drive cams having cam surfaces for different presser foot vertical drive patterns. The cam follower includes a switching unit for selection of one drive cam from the presser foot drive cam.

A presser foot vertical drive device includes an upper shaft configured to vertically drive a needle, a presser foot drive cam fixed to the upper shaft, a presser foot urged downward over a needle plate, a cam follower configured to be vertically driven in contact with the presser foot drive cam, and a link configured to transmit the vertical drive of the cam follower to the presser foot. The presser foot drive cam includes a plurality of drive cams having cam surfaces for different presser foot vertical drive patterns. The cam follower includes a switching unit for selection of one drive cam from the presser foot drive cam.

Sewing machine ankle assemblies having a resilient member for attaching a presser foot are disclosed. According to an aspect, a sewing machine ankle assembly includes an ankle comprising an upper portion and a lower portion. The lower portion defines at least one structure configured to receive an attachment mechanism of the presser foot. The sewing machine ankle assembly also includes a resilient member comprising an upper end and an opposing lower end. The upper end is attached to the upper portion of the ankle. The lower end is positioned beneath a portion of the attachment mechanism of the presser foot when the attachment mechanism is received by the at least one structure of the ankle such that the lower portion of the resilient member exerts a force on the portion of the attachment mechanism in a direction towards the at least one structure of the ankle.

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.