Abstract: A sewing machine for and a method of stitching a mark of a predetermined shape onto a fabric, in which the mark is stitched onto the fabric by selective employment of stitch patterns stored in a memory device of the sewing machine and wherein selected patterns form a single pattern of stitches corresponding to the predetermined shape of the mark.

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: In an apparatus for detecting and displaying a residual quantity of lower or under thread (12) of a sewing machine, an under-thread bobbin (10) is provided with transparent flange portions (10a) permitting the light rays emitted from a light emitting device of a photosensor (19) to pass through the flange portions (10a ) of the bobbin (10). The light rays having passed through the bobbin (10) are then reflected by a reflecting means or mirror (21) affixed to a back surface of a bed of the sewing machine to impinge on a light receiving device of the photosensor (19) so that the photosensor (19) detects the residual quantity of the lower thread (12) of the sewing machine. In the photosensor (19), the light emitting device is integrally formed with the light receiving device to save space.

Abstract: 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.

Abstract: A sewing machine has a front operating panel secured thereto and a pattern selecting device. A pivotable pattern table is mounted on the lower end of the operating panel and an inside surface of the pattern table has a pattern indicating device. The pattern table is rotatable from a closed position in which an outside surface is flush with the outside surface of the operating panel and into an open position in which its outside surface is resting on the sewing machine frame so that both the pattern indicating means and pattern selecting devices are simultaneously visible to a machine operator. The pattern table is pivotably supported on a shaft supported in a bearing located at the lower end of the operating panel.

Abstract: 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.

Abstract: 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.

Abstract: A sewing machine having a vertically reciprocating needle carrying an upper thread, a needle plate secured to a sewing machine housing and provided with a needle penetrating hole, a loop-taker arranged below the needle plate and operated in synchronism with reciprocation of the needle for interlocking a lower thread carried thereby with the upper thread, and a feed dog for feeding a fabric placed on the needle plate in a predetermined direction on which a stitch composed of the interlocked upper and lower threads has been formed. A swingable arm is operated to interfere with the normal travelling path of the lower thread between the loop-taker and the needle hole to draw a predetermined amount of the lower thread out of the loop-taker, while the fabric is not being fed.

Abstract: 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.

Abstract: A thread guiding device in a sewing machine comprising a guide path for guiding an upper thread from a thread source to a needle and defined by a first thread guide, a pair of discs for releasably holding an upper thread, and a second thread guide formed by a spring hook of a thread tension spring member and an end portion of a take-up lever, the first and second thread guide and the thread tension spring member lying in a common plane to define a straight-line guide path.

Abstract: In a sewing machine provided with a needle position adjusting device to position a needle relative to a basic line, a switching arrangement is provided to switch the needle position adjusting means from a needle amplitude adjusting mode to a mode of adjusting the needle basic line, whereby one adjusting device may be used as a needle amplitude adjusting device for ordinary stitching patterns and as a needle basic line-adjusting device for specific stitching patterns.

Abstract: In a sewing machine which stores stitch control signals in an electronic memory composed with a microcomputer, incorporated therein are a stitch selecting device, a blindstitching depth setting device and a blindstitching width setting device which are both independently set by operation of said stitch selecting device. When a blindstitching pattern is selected, said depth setting device and width setting device are made operative, and needle dropping left positions are set by said depth setting device, and right dropping positions or whole amplitudes are set by said width setting device, and they are input to the memory for forming the blindstitching patterns by the stitching control signal of the blindstitching pattern.

Abstract: A method for automatically stitching by a zigzag sewing machine a button hole, which includes two line-tack stitching parts stitched sequentially, comprises applying a predetermined amount of fabric feeding to a first group of alternate stitches in both line-tack stitching parts, and then applying no fabric feeding to a second group of alternate stitches in the line-tack stitching parts by not moving the fabric relative to the needle in any direction. Inclined stitches and non-inclined stitches which alternate with each other result in each line-tack stitching part.

Abstract: A devised shank is provided to a presser foot of a sewing machine in addition to an ordinary shank, such that a special presser group for straight stitching along a fabric edge is attached to the devised shank only, in which the presser foot is attachable to a presser holder, and the ordinary shank is for such as zigzag stitching, and the devised shank is different in an attaching width from the ordinary shank. Signal generating parts are provided to the presser holder, which each issue a signal in response to when the presser foot is attached, and the signal is discriminated with a signal issued in response to a pattern group belonging to patterns selected by a pattern selecting means so that the sewing machine is driven only when the presser group and the pattern group is met.

Abstract: In a sewing machine having two mechanisms different in sewing functions installed within one machine frame a single drive motor is provided and functions are alternately actuated by means of a clutch mechanism. Transmission of a driving force is made by keys and corresponding key grooves, and a selection mechanism has a switch-checking device for avoiding an erroneous operation. A release device of the switch-checking device is actuated by operation of the flywheel, to avoid dangers of erroneous switching during operation.

Abstract: 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.

Abstract: 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.

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: There is a zigzag sewing machine provided with a horizontal rotary loop taker device which is restrained with respect to the rotation direction, and holds therein a bobbin carrier horizontally attached, and is supplied with a lower threads from the left side to the left basic line marked with an axial line in front of the needle, and provided with a feed dog which is provided nearly to passage of the needle to move vertically and laterally. In such a sewing machine a cam portion is provided for supplying the lower thread to a lower thread contacting portion of the bobbin carrier or a lower thread contacting portion of a part connecting right and left teeth of the feed dog, whereby the amount of supplying the lower thread is adjusted properly with respect to the left basic line and the right basic line during zigzag stitching, and the slack amount of the lower thread is adjusted properly with respect to the left basic line and the right basic line during forming stitches.