A thread take-up lever switching mechanism can switch the operation of a thread take-up lever which is interlocked with an upper shaft. The thread take-up lever switching mechanism includes: a cylindrical cam provided on the upper shaft, the cylindrical cam having a plurality of cam surfaces; a contact portion provided on the thread take-up lever, the contact portion contacting a first surface of the plurality of cam surfaces; and a switch for switching the contact portion from a first position of contacting the first surface of the plurality of cam surfaces to a second position of contacting a second surface of the plurality of cam surfaces.

A thread take-up lever switching mechanism can switch the operation of a thread take-up lever which is interlocked with an upper shaft. The thread take-up lever switching mechanism includes: a cylindrical cam provided on the upper shaft, the cylindrical cam having a plurality of cam surfaces; a contact portion provided on the thread take-up lever, the contact portion contacting a first surface of the plurality of cam surfaces; and a switch for switching the contact portion from a first position of contacting the first surface of the plurality of cam surfaces to a second position of contacting a second surface of the plurality of cam surfaces.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.

A thread take-up lever switching mechanism can switch the operation of a thread take-up lever which is interlocked with an upper shaft. The thread take-up lever switching mechanism includes: a cylindrical cam provided on the upper shaft, the cylindrical cam having a plurality of cam surfaces; a contact portion provided on the thread take-up lever, the contact portion contacting a first surface of the plurality of cam surfaces; and a switch for switching the contact portion from a first position of contacting the first surface of the plurality of cam surfaces to a second position of contacting a second surface of the plurality of cam surfaces.

A thread take-up lever switching mechanism can switch the operation of a thread take-up lever which is interlocked with an upper shaft. The thread take-up lever switching mechanism includes: a cylindrical cam provided on the upper shaft, the cylindrical cam having a plurality of cam surfaces; a contact portion provided on the thread take-up lever, the contact portion contacting a first surface of the plurality of cam surfaces; and a switch for switching the contact portion from a first position of contacting the first surface of the plurality of cam surfaces to a second position of contacting a second surface of the plurality of cam surfaces.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.

The length of a sewing machine stitch is adjustable by varying the effective length of a first bar of a multi-bar linkage operably secured to a feed dog of the sewing machine. The effective length of the first bar is defined between an anchor point and a pivot point, with the pivot point being secured to a slider configured for movement along the length of the first bar. The slider comprises a pinion gear configured to engage a gear rack of the first bar, such that rotation of the pinion gear causes movement of the slider and the pivot point relative to the anchor point. Moreover, to accommodate the adjustable stitch length, the sewing machine additionally comprises an adjustable looper thread eyelet configured to adjust the length of the looper thread path to accommodate increased tension or slack in the looper thread due to the changed stitch length.