US 5,345,887 A · Thread manipulations at the beginning and end of a seam

Abstract

A thread-pulling device is fastened on the arm of a sewing machine. The thread-pulling device has a thread clamp that can be opened and closed on the thread, and can be moved toward and away from the sewing machine arm. In operation, the needle thread, which has been pulled off the spool and extends to the sewing needle, is conducted through the thread clamp. After an initial seam has been completed, the thread clamp is closed on the thread and moved to an extended position which is remote from the arm. In this way, a given length of the needle thread is pulled off the spool, thus providing the proper length of needle thread for dependable formation of the first stitch of the following seam. Then, shortly after the start of the following sewing process, the thread clamp is moved back over an intermediate distance toward the sewing machine arm so as to pull back the initial piece of the needle thread that is now hanging down from the back of the material at the start of the seam. The initial piece of needle thread is pulled back to such an extent that only a short piece of the needle thread, of predetermined length, will remain on the back of the material.

Claims28

Dependent claims

A method of producing a sewing seam with an attractive appearance, comprising the steps of:

cutting a needle thread and a bobbin thread at the end of a previous first seam such that a trailing end portion of the needle thread hangs out from a sewing needle, and then
forming a subsequent second seam in a material to be sewn,
wherein in an initial phase of forming the subsequent second seam, said trailing end portion of the needle thread is located so as to hang from an underside of the material and is provided with a first predetermined length by pulling the needle thread back from said material, so that only a short piece of needle thread having said first predetermined length remains on the underside of the material when said second seam is produced, thereby producing a sewing seam with an attractive appearance.

A device in a sewing machine for producing a sewing seam with an attractive appearance, comprising:

a first device for cutting a needle thread and a bobbin thread in said sewing machine at the end of a previous first seam such that, after cutting, a trailing end portion of the needle thread hangs out from a sewing needle, said trailing end portion of the needle thread being provided for the formation of a subsequent second seam;
and
a second device for providing said trailing end portion of the needle thread, located so as to hang from an underside of a material to be sewn, with a first predetermined length, by pulling the needle thread back from the material so that only a piece of needle thread having said first predetermined length remains on the underside of the material when said subsequent second seam is produced in said material, thereby producing a sewing seam with an attractive appearance.

A method of producing a sewing seam with an attractive appearance, comprising the steps of:

cutting a needle thread and a bobbin thread at the end of a previous first seam such that a trailing end portion of the needle thread hangs out from a sewing needle,
and a trailing end portion of a bobbin thread hangs out from a looper, both end portions being provided for the formation of a subsequent first stitch;
and
forming a subsequent second seam in a material to be sewn,
wherein in an initial phase of forming the subsequent second seam, said trailing end portion of the needle thread is located so as to hang from an underside of the material and is provided with a first predetermined length by pulling the needle thread back from said material, so that only a short piece of needle thread having said first predetermined length remains on the underside of the material when said second seam is produced, thereby producing a sewing seam with an attractive appearance.

2 more elements

A device in a sewing machine for producing a sewing seam with an attractive appearance, comprising:

a first device for cutting a needle thread and a bobbin thread in said sewing machine at the end of a previous first seam such that, after cutting, a trailing end portion of the needle thread hangs out of a sewing needle and a trailing end portion of a bobbin thread hangs out from a looper, both end portions being provided for the formation of a subsequent first stitch;
and
a second device for providing said trailing end portion of the needle thread, located so as to hang from an underside of a material to be sewn, with a first predetermined length, by pulling the needle thread back from the material so that only a piece of needle thread having said first predetermined length remains on the underside of the material when said subsequent second seam is produced in said material, thereby producing a sewing seam with an attractive appearance.

Dependencies are inferred from the claim text.

Thread manipulations at the beginning and end of a seam

Life of this patent

Thread manipulations at the beginning and end of a seam

Life of this patent

Abstract

Claims28