Abstract: Embroidery pattern positioning apparatus and embroidering apparatus is disclosed, wherein a pattern is projected on a cloth F on which the pattern is embroidered. The projected pattern is moved on the cloth by operation of jog keys 6 to determine a position of the pattern where the pattern is stitched. In the meantime the original position of a carriage is adjusted or the position of the pattern is calculated and memorized in accordance with the moving amount of the pattern. This operation may be repeated as to each of plural patterns selected to be stitched such that a plurality of patterns may be stitched respectively at the positions determined and memorized.

Abstract: An embroidering position setting device and method of operation thereof for an embroidering sewing machine are described. The embroidering sewing machine is capable of storing pattern data in a memory for a plurality of embroidery patterns which can be selectively read out to operate a stitch forming device to form the stitches of a selected pattern or patterns on a cloth to be stitched. An embroidering frame has a cloth extended thereon to be embroidered and is connected to an X-Y drive mechanism, said cloth having a mark located at an optional position for representing a reference embroidering position of the cloth. Jog keys are selectively operated to operate said X-Y drive mechanism thereby to shift said embroidering frame so that said reference embroidering position mark of the cloth may be located at the position under said machine needle in vertical alignment therewith.

Abstract: 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.

Abstract: An apparatus for adjusting the size of a sewing machine pattern for use in a sewing machine is disclosed. The apparatus includes a stitch data storage device for storing stitch data corresponding to each of a plurality of embroidery patterns; a pattern selecting device for selecting a desired one of the plurality of patterns stored in the storage device; a magnification selecting device capable of being manually operated for adjusting the size of the pattern; a magnification displaying device for displaying an adjustment value selected by the magnification selecting device; a key code determining device for determining the stitch data to be valid or invalid on the basis of a relevant one of key codes respectively added to a plurality of items of stitch data for forming the pattern in correspondence with the adjustment value selected; and a size adjusting device for adjusting the size of the pattern in correspondence with the adjustment value selected.

Abstract: 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.

Abstract: A sewing machine capable of setting a feed pitch of a first stitch on zero in a work piece at the beginning of sewing operation, comprises: a needle reciprocable in a vertical direction and joggable in a lateral direction; a feed means which cooperates with a presser foot in operation in synchronism with the needle for feeding a work piece at a desired rate; a stitch-forming mechanism driven by a main drive motor of the sewing machine; a motor-operation detecting means for detecting operating conditions of the main drive motor; a needle-position detecting means for detecting a position of the needle having been disposed above a throat plate; and a presser-foot position detecting means for detecting a position of the presser foot relative to the throat plate, whereby a feed pitch of the feed means is set on zero at a time when the motor-operation detecting means detects a stopping condition of the main drive motor, so that a condition in which the feed pitch of the feed means is set on zero is held until a sub

Abstract: 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.

Abstract: 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.

Abstract: A lower thread drawing-out device for a computerized sewing machine, the device having a cup-shaped loop taker with a surrounding wall. The loop taker is rotatable in a timed relation with a vertical reciprocation of the needle to catch the upper thread to concatenate with the lower thread and thereby form lock stitches. A bobbin is arranged in the loop taker so as to form a space between the bobbin and the loop taker surrounding wall. A lower thread drawing out element having a free end in the space is arranged so that when a lower thread is wrapped around the bobbin and extends to a needle, the free end contacts the lower thread at a location. The lower thread drawing out element is rotatable relative to the loop taker. The lower thread is movable transversely at the contact location relative to the lower thread when extended and in response to a rotation of the element relative to the loop taker, thereby compensating for biasing of the lower thread.

Abstract: An automatic thread tension adjusting device for a sewing machine designed to automatically adjust the tension of upper thread to produce desired stitches each formed with the upper and lower threads interlocked with each other within the thickness of a fabric to be sewn, the interlocking position of the threads depending upon the types of stitches such as the straight stitches and zigzag stitches. The thread is held and drawn-out at predetermined angular positions of an upper drive shaft, which are detected by sensors to thereby draw out a required amount of upper thread depending upon the thickness of the fabric and the type of stitches. The required amount of the upper thread is supplied to a thread take-up lever to determine the upper thread tension during the formation process of each stitch.

Abstract: A tension setting device of the sewing machine comprises an upper thread tension device on the machine frame. A selecting device for selecting a thread tension in response to a thickness of a fabric being sewn is mounted to the machine frame. An auxiliary upper thread tension device cooperating with the selecting device and actuated thereby to adjust upper thread tension in response to the thickness of the fabric is provided in the tension setting device. A lower thread adjusting device cooperates with the thread tension selecting device to adjust the lower thread in response to the thickness of the fabric being sewn.

Abstract: A sewing machine needle is capable of vertically reciprocating between upper and lower dead points and swinging laterally within a predetermined amplitude between two extreme lateral positions to form zigzag stitches on a fabric material in cooperation with a hook of a rotary loop taker. The needle comprises a relatively thick upper base portion by which the needle is attached to a needle bar of the sewing machine and a shank formed integrally with the upper base portion and adapted to reciprocatingly pass through the fabric material.