Tokyo Juki Industrial Co., Ltd.

Juki Corporation

Sumio Goto

Masao Nakamura

Nozomi Iwasaki

Hiroyuki Tomioka

Takayoshi Mori

Jiro Ishibashi

Masakazu Nemoto

Kuniharu Sakuma

Toru Matsubara

Ikuro Iimura

Kazuo Saito

An under thread supply apparatus for a sewing machine comprises a bobbin case, a bobbin exchange device, a thread removal device and a winding device. The bobbin case is removably set to a shuttle of the sewing machine and accommodates a bobbin with the thread wound thereon. The bobbin exchange device takes the bobbin case out of the shuttle, and set the bobbin case accommodating the bobbin with the thread wound anew therearound to the shuttle. The thread removal device removes the thread from the bobbin accommodated in the bobbin case which is taken out. The winding device winds a preset amount of thread around the bobbin after the thread is removed therefrom.

Under thread supply apparatus and method of supplying under thread

An under thread supply apparatus for a sewing machine comprises a bobbin case, a bobbin exchange device, a thread removal device and a winding device. The bobbin case is removably set to a shuttle of the sewing machine and accommodates a bobbin with the thread wound thereon. The bobbin exchange device takes the bobbin case out of the shuttle, and sets the bobbin case accommodating the bobbin with the thread wound anew therearound to the shuttle. The thread removal device removes the thread from the bobbin accommodated in the bobbin case which is taken out. The winding device winds a preset amount of thread around the bobbin after the thread is removed therefrom.

A bobbin thread removing device includes a bobbin rotatably supported on the bobbin thread removing device; pull-out apparatus for pulling out a thread wound on the bobbin; bobbin rotation detecting device for detecting the rotation of the bobbin from which the thread is being removed; and control device receiving a signal from the bobbin rotation detecting devices, for driving the pull-out apparatus to pull the thread out again when the control device detects that the bobbin is not turning in accordance with the signal from the bobbin rotation detecting devices.

Bobbin thread removing device

A sewing machine automatically sews a seam which ends at a desired point. The last n stitches, preferably the last two stitches, are of substantially equal length. A counter counts pulses while the work is being fed to the needle. The machine detects when the trailing edge of the work passes by a predetermined location ahead of the needle. Upon such detection, the contents of the counter are used to calculate the proper stitch pitch for the last two stitches. The stitch pitch is varied as necessary during sewing of the last two stitches in the seam.

Sewing machine for automatically sewing neat seam ends

An automatic stitch pitch adjusting apparatus for a sewing machine allows the last stitch point to be terminated at a pre-set point. Three workpiece-end sensors are positioned respective a needle hole position to precisely calculate the required actual stitch line length. Reference signals generated by rotation of a main shaft are used to calculate both the required number of stitchings and the adjusted stitch pitch to terminate stitching at the pre-set point. Where the workpiece end line is not normal against the feeding line, the pre-set margin distance is adjusted to calculate the actual required stitching line length to the last pre-set point.

Apparatus for automatically adjusting the stitch pitch of a sewing

A sewing machine capable of multiple functions including terminating stitches at a predetermined point, carrying out predetermined stitch patterns, automatic stitch pitch adjustment, stopping at preset points and thread cutting without operator intervention. These operations are controlled by means of a computer interface with the sewing machine and can carry out labeling, pocket attachment, collar attachment, cuffs etc. at preset intervals.

Method and apparatus for performing sewing operations utilizing sewing

A thread feed device in a sewing machine is disclosed herein. The device comprises a thread paying-out member positioned in the thread path between the bobbin and needle, a pair of holding means positioned upstream and downstream of the paying-out member in the thread path and a control circuit for controlling of the operation of the holding means.

Thread feed device in a sewing machine

A thread feed mechanism in a sewing machine for paying-out thread in a predetermined amount necessary for forming one seam. The thread feed mechanism comprises a first signal generation device for producing feed amount and needle bar amplitude signals, a second signal generation device for producing a workpiece thickness signal, first means for adding square values of feed amount and amplitude signals, second means for multiplying a square root of the first means by a coefficient, third means for producing a signal varying depending upon the operation mode thereof, fourth means for multiplying a workpiece thickness signal by the output of the third means, and fifth means for adding the outputs of the second, third and fourth means.

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Tokyo, Japan

Sumio Goto