Janome Sewing Machine Company Limited

Janome Sewing Machine Industry Co., Ltd.

Kazumasa Hara

Mikio Koike

Susumu Hanyu

Noboru Kasuga

Akiyoshi Sasano

Mitsuru Nishijima

Yasuro Sano

Yasukata Eguchi

Koichi Watanabe

Yasuhiro Suzuki

Kenji Kaneko

Masashi Sato

Haruhiko Tanaka

Michio Hisatake

Reishi Nomoto

Akio Koide

Shuzo Morimoto

Koji Okutani

Hidechika Kuramoto

Shinichi Fukada

Kenzo Goto

Noburu Kasuga

Mituru Nishijima

Mitsuru Ninijima

Noboru Karuga

A sewing machine capable of embroidery stitching and a embroidery data producing device for the machine are formed so that optionally selectable data are provided for forming the stitches of unit patterns to be embroidered, for arranging the unit pattern in series along a linear outline forming a looped pattern, for setting the size and the number of the unit patterns, the space between the unit patterns in an arrangement thereof and the size of the looped pattern, and stitch forming means is operated under control of said given data to form the stitches of the unit patterns arranged along the linear outline.

Sewing machine capable of embroidery stitching, and embroidery data

An upper thread carried by a vertically reciprocating needle is drawn from a bobbin through a tensioning device, a supply device and a take-up lever. A predetermined amount of the upper thread is first supplied by actuating the supply device, while applying no tension thereto. An additional amount of the upper thread is then supplied by operation of the take-up lever with a predetermined tension being given thereto. The additional amount is detected by a sensor. The supply device includes a one-way clutch for allowing the upper thread to travel in a predetermined direction which, however, may not be conveyed from the needle side when the supply device is made operative. A CPU controls the amount of thread first supplied by the supply device which will always be smaller than an amount actually required for producing a stitch, resulting in an additional amount to be supplied supplemental in cooperation with the tensioning device.

Upper thread supplying device in sewing machine

A device for guiding a lower thread in a zigzag stitching sewing machine is provided with a lower thread guiding unit that determines two lower thread drawing positions in accordance with a selected pattern. The lower thread guiding unit includes a lower thread guiding part which, at one of the two positions, acts on the lower thread to guide a lower thread drawing position to a center of a needle amplitude. A lower thread releasing element, at the other of the two positions, cooperates with the lower thread guiding unit to release the lower thread engaged with the lower thread guiding part.

Device for guiding a lower thread in a sewing machine

A method of automatically controlling thread tension in a sewing machine according to which a first thread tension device is provided between an upper thread source and a thread take-up lever, and a second thread tension device is provided between the first tension device and the thread take-up lever. The first thread tension device is operated to apply a constant pressure to the upper thread such that the thread take-up lever is able to draw out the upper thread upon moving upward. The second thread tension device is operated to fixedly hold the upper thread until the thread take-up lever moves upward to an upper dead point thereof through a lower dead point thereof, at which the take-up lever moves downward to supply the upper thread to the needle. The second thread tension device is further operated to effect release of the upper thread when the thread take-up lever reaches the upper dead point thereof and until the thread take-up lever moves downward to a thread supply starting position thereof.

Method of automatically controlling upper thread tension in a sewing

An automatic thread tension control sewing machine comprising thread tension controller for clamping an upper thread with a predetermined pressure to control an amount of the upper thread supplied to a needle and a loop taker, thread tension setting means that determines a pressure with which the thread tension controller clamps the upper thread, upper thread supplying mechanism, a releasing mechanism controlling operation of the upper thread supplying mechanism, and a central processing unit for actuating the releasing mechanism in accordance with a selected stitch pattern.

Automatic thread tension control sewing machine

A sewing machine includes an automatic thread tension adjusting device comprising an upper thread tension member arranged in an a thread running path between an upper thread source and a main thread take-up lever. An auxiliary thread take-up lever is arranged in the upper thread running path between the main thread take-up lever and a needle holding the upper thread. A thread engaging part guides the upper thread. A thread presser is arranged laterally of the upper thread running path between the main and auxiliary thread take-up levers and normally clamps the upper thread. A detector detects a predetermined rotation phase of a drive shaft of the machine and thread elongation, respectively, and generates respective electric signals. A control circuit causes the thread presser to release the upper thread in response to the electric signals generated by the detector.

Sewing machine automatic thread tension device with thread elongation

A sewing machine comprises a thread deflecting device arranged between a thread take-up lever and a needle and which in response to a swinging movement of a needle bar effected in response to selection of a zigzag stitch, deflects the upper thread laterally of a fabric feeding direction. A thread blocking device is provided on one side of the thread deflecting device. The sewing machine further comprises an actuator operated in response to actuation of a zigzag stitch pattern selecting key to move the thread blocking device to an operative position thereof. The thread blocking device in the operative position blocks the upper thread as it is deflected in one direction by the thread deflecting device to give a predetermined degree of tension to the upper thread, so that the stitch is tightened on one side of the zigzag stitch in addition to the tightening of the stitch by a thread take-up lever.

Sewing machine with a device for amending thread tightening by needle

A zigzag sewing machine includes a needle hole member having a round needle hole of a diameter slightly larger than that of a stitching needle. The needle hole member engages a laterally elongated hole in a needle plate and is swingable along the latter. A base member is mounted coaxially with a loop taker and is rotatable relative to the loop taker. The needle hole member is pivoted to the base member for relative vertically swinging movement. A lever swingably mounted on the machine housing engages with the needle hole member, and a cam rotated in synchronism with the vertical reciprocation of the needle is in engagement with the swinging lever. A stepping motor is operatively connected to the needle to reciprocate the needle laterally in the elongated needle plate hole, and the motor is also operatively connected to the base member to reciprocate the base member.

Needle hole guide mechanism for zigzag sewing machine

A lower thread tension adjusting device for a sewing machine comprising first and second tension arrangements mounted on a bobbin carrier of the sewing machine for tensioning a lower thread with a predetermined tension and a predetermined additional tension, respectively. A positioning device is mounted on the bobbin carrier and movable between first and second set positions in which the positioning devices moves the second tension arrangement to operative and inoperative positions wherein the second arrangement provides and does not provide the predetermined additional tension of the lower thread. A guide assembly guides the lower thread to positions adjacent to one end and a center of a laterally elongated needle hole and simultaneously guides the positioning device to the first and second positions thereof. A control unit moves the guide assembly between first and second guide positions thereof in accordance with selected patterns of straight and zigzag stitches, respectively.

Device for adjusting a lower thread in a sewing machine

A sewing machine having an upper thread supply, a main thread take-up lever and a needle, is provided with an automatic upper thread tension device for absorbing slackening of the upper thread during its supplying phase. The tension device includes a thread tension member arranged between the upper thread supply and the main thread take up lever to impart an adjustable pretension to the upper thread. A thread presser is arranged laterally of the path of the upper thread between the main thread take-up lever and the needle to guide the upper thread from the thread tension member to the main thread take-up lever and to clamp the upper thread and release the same during the predetermined supplying phase. An auxiliary thread take-up lever is arranged between the main take-up lever and the needle and cooperating with a thread guide to draw the slackened part of the upper thread against the guide during the supplying phase.

Automatic thread tightening device for a sewing machine

An automatic thread tensioning device for positioning the crossing points of upper and lower threads in the center of thickness of a fabric undergoing stitching. The positioning is effected by making calculations based on measured results of thread tension, without needing to detect the various kinds of characteristics of fabrics, threads, or lower thread tension responding to an existing type of stitching condition. The proper upper thread tension may be determined for the stitching conditions of fabrics which have different characteristics and for stitching conditions of fabrics which have conventionally been difficult to deal with, simply by pressing buttons and making test stitchings. If an upper thread tensioning device has a motor, a stitching operation may be made more easily.

Automatic thread tension device for a sewing machine

A device for changing a lower thread running path in a zigzag sewing machine includes a guiding member positioned between a lower thread holder and a needle plate and having an obliquely positioned guiding face the obliquity of which to the direction of the needle amplitude is controlled to selectively produce straight stitches or zigzag stitches.

Device for changing a lower thread running path for a zigzag sewing

A lower thread tension device is provided in association with adjustment of an upper thread tension device in such a manner that when the tension of the upper thread tension device is strong within an adjusting range, the lower thread tension is adjusted strongly, and when the tension of the upper thread tension device is weak within the adjusting range, the lower thread tension is adjusted weakly. The upper and lower thread tension device includes a dial for adjusting an upper thread tension, a potentiometer connected to the dial, and an electromagnet with an actuator acting on the lower thread to adjust its tension in response to a signal received from the potentiometer due to rotation of the dial. The upper and lower thread tension device includes a dial for adjusting an upper thread tension, a potentiometer connected to the dial, and an electromagnet with an actuator acting on the lower thread to adjust its tension in response to a signal received from the potentiometer due to rotation of the dial.

Upper and lower thread tension devices for sewing machine

This invention makes a proper calculation to an amount of supplying a lower thread to be required to forming of a stitch with stitching information in relation with changing of a needle dropping position from a preceding stitch to a present stitching, so that the lower thread is forcibly drawn out in accordance with said calculation, and makes a proper calculation to tension of an upper thread optimum to forming of a stitch with stitching information so as to determine the optimum upper thread tension in accordance with said calculation, or makes a calculation to the amount of supplying the upper thread optimum to forming of a stitch with stitching information so as to draw out the upper thread in accordance with said calculation.

Sewing machine with an automatic thread tension device

When a lower thread is effected with tension by an upper thread, a lower thread tension device is actuated in a certain working distance with very small resistance to an extent that a lower thread is drawn as if without resistance. If the lower thread is effected with said tension outside of said distance, it is not drawn out with large resistance. An actuation means successively receives information about thread consumed in each of the stitches and information about rotation phase of the sewing machine from a phase sensor. In the distance of a strong resistance, the lower thread is prohibited from drawing, and the thread is tightened in this distance.

Growing community of inventors

Tokyo, Japan

Kazumasa Hara