Janome Sewing Machine Company Limited

Yoshinobu Tonomura

Hideaki Takenoya

Susumu Hanyu

Kazuo Watanabe

Hachiro Makabe

Eiichi Shomura

Tamotsu Nakagawa

Toshiro Fujimura

Toshio Fujimura

Tsuneo Takayama

A method is disclosed in which all patterns to be sewn by an electronic sewing machine are divided into individual unit patterns. Stitch data characteristic of common unit patterns which find application in more than one pattern to be sewn is stored only once in a read-only memory. As a result, wasted space in a read-only memory caused by unnecessary repeated storage of the same stitch data pertaining to common unit patterns is eliminated. This method makes it possible to store more patterns within a read-only memory of a given size and further enables more complicated patterns to be sewn.

Method of producing stitch patterns in an electronic sewing machine

An automatic thread setting device for electronically controlled material and needle position type sewing machines. The device has pattern selecting means, cloth thickness designating means, upper and lower thread tension adjusting means, and electronic memory means. Selection of a pattern automatically sets the thread tension. Selection of a different pattern automatically resets the tension.

Automatic thread tensioning device for sewing machines

An electric sewing machine has an A.C. driving motor controlled by a triac; a controlling circuit for the triac includes a thyristor powered by a lower-voltage battery via an adjustable RC-circuit; the controlling circuit is electrically insulated from the A.C. power-supply circuit by an optoelectric coupler, the optical part of which is connected to the A.C. circuit and the electric part of which controls the gate of the thyristor in synchronism with the A.C. voltage; the thyristor in the controlling circuit is coupled to the triac by means of an insulating pulse transformer.

Speed control device for sewing machines

A device for automatically adjusting the tension of a lower thread, which comprises a lower thread bobbin arranged on a bottom plate of a bobbin carrier turnably carrying the bobbin, a loop taker mounted on a magnetic shaft, and an energizing coil arranged around the magnetic shaft and providing together with said bottom plate and magnetic shaft a path of magnetic flux. The device is further provided with a detector detecting the consumed amount of the bobbin thread and a control circuit for energizing the coil when the lower thread is wound to the maximum capacity of the bobbin, interrupting the light of the detector. The detector operates the control circuit to decrease the amount of electric current applied to the energizing coil so as to set the lower thread tension back to its initial predetermined value.

Bobbin thread tensioning device for a sewing machine

An electronic pattern stitch sewing machine is disclosed in which a pattern can be progressively enlarged and reduced at the beginnings thereof under control of a central processing unit (CPU).

Pattern generator for electronic sewing machines

When a pulse motor in an electronic sewing machine is to be subjected to a heavy load, the pulse motor is operated at a slower speed in order to cause the pulse motor to operate at a rate in which it has a maximum torque output. For lesser load conditions, pulse motor speed is allowed to increase. Speed control of the pulse motor follows a generally trapezoidal curve, which curve includes a speed-up section and a slow-down section, and may include a flat section. That portion of the generally trapezoidal curve along which motor speed follows is determined by the distance which the pulse motor is required to move.

Electronic sewing machine

A speed control device for a sewing machine which is adapted to control a speed of the machine motor. The device includes a plurality of photo-conductive fibers arranged in two sets, one set being optically positioned opposite to another. The device also includes a light source which transmits the light to the photo-conductive fibers, a photo-conductive element which receives the light from the fibers and a phase-controlling element connected to the photo-conductive element and to the machine motor. An interrupting plate secured to a step plate of the sewing machine is provided in the device which is adapted for reciprocable movement between the optically sensitive ends of aforementioned two sets of the photo-conductive fibers. The photo-conductive element generates an ignition current in the phase-controlling element in response to a predetermined amount of light transmitted from one set of fibers connected to the light source to another one whereby the phase-controlling element effects the machine motor to change the speed thereof.

Speed control device of sewing machines

An automatic embroidery machine is driven by information recorded on magnetic tape and utilizes a fixed sewing machine and a movable embroidery frame. An input apparatus registers user-selected points on a coordinate analysis panel, which points form embroidery patterns to be sewn, and causes embroidery information to be recorded upon magnetic tape for subsequent use in the automatic embroidery machine. The automatic embroidery machine and the input apparatus are so designed that after a continuous part of an embroidery pattern has been sewn, the embroidery frame will be moved to a next continuous part of a pattern and the automatic embroidering machine will stop, providing an opportunity for a user to change thread. The automatic embroidering machine cannot be restarted unless the user operates a controller, ensuring safe operation. The automatic embroidery machine is provided with a temporary memory, into which embroidery information is written while the magnetic tape is being read, and from which embroidery information is read out while the automatic embroidering machine is embroidering patterns. The input apparatus is so designed that when an amount of embroidery information corresponding to the predetermined capacity of the temporary memory has been recorded on the magnetic tape, a blank signal is next recorded thereon. The magnetic tape is repeatedly started and stopped, so that embroidery information is transferred in packets into and out of the temporary memory. This operation allows temporary memory capacity to be minimized, reducing cost.

Apparatus for writing and using embroidery information on magnetic tape

A sewing machine can accept a plurality of presser feet for specific stitching applications. The invention adjusts lateral movement of the needle, feed dog operation, and needle hole size at the needle plate to conform with the presser foot used, and to thereby prevent needle breakage and skipped stitches.

Sewing machine with stitch type identifying device

The tension of the sewing machine's upper thread is varied automatically, in a variety of ways not requiring conscious participation on the part of the user of the machine. When one of a set of selectable stitch-patterns is selected by the user, an appropriate thread-tension value is automatically established, although the user retains the ability to adjust the automatically established tension value if he wishes. When the user swings the presser-foot lever of the machine up, to raise the cloth presser foot up from the cloth, e.g., for basting work, the thread tension is automatically lowered to a predetermined value suitable for basting, although still adjustable by the user if he thinks necessary. Where a stitch-pattern is implemented using an addressable ROM, tension command data for each stitch of the stitch-pattern may be stored in the ROM, for variation of thread tension from constituent stitch of the pattern to the next. Alternatively, the ROM stores no tension control data per se, and instead a calculating circuit calculates, from the mere stitch-control data presented by the ROM, distance-dependent values dependent upon the distances between successive needle-penetration locations of the stitch-pattern, and from those derives appropriate tension command signals.

Sewing machine with thread-tension control system

The invention relates to a sewing machine and more particularly relates to a device for directly driving the fabric feeding shaft of the sewing machine independently of the upper main shaft and the lower loop taker drive shaft so as to secure a correct movement of the feeding shaft in a timed relation with the upper main shaft and the lower loop taker drive shaft for the purpose of avoiding the breakage of the needle and the formation of loosened stitches.

Sewing machine with a device for directly driving the feeding shaft

An electronic pattern stitching sewing machine has an arrangement for producing signals directing it to stitch a selectable number of patterns in series. These signals are then used to identify the last needle position coordinate of a preceding stitched pattern of the series and the initial needle position coordinate of the next-following pattern to be stitched in the series and, in dependence upon this, the most appropriate interconnecting pattern from a memorized group of such interconnected patterns is selected and stitched, so as to interconnect the preceding stitched pattern and the next-following pattern of the series.

Growing community of inventors

Hachioji, Japan

Yoshinobu Tonomura