Abstract: There is disclosed a motor speed control system particularly applicable to control sewing machine operation, including an evaluator to compare a preset speed of revolution value and an actual speed of revolution value to output one signal representing a deviation between the two speeds and the other representing a rate of increase or decrease of the actual speed of revolution within a predetermined short interval. In response to these parameter signals, one of the stored fuzzy rules is selectively applied to output an appropriate control signal to change electric power supplied to a motor as needed to adjust the speed of revolution toward the preset revolution with quick responsivity and smooth transition.

Abstract: A control system is provided for stopping a sewing machine needle at a predetermined position within its reciprocating path. An upper drive shaft rotating at a given rotational speed tends to decrease towards a predetermined lower rotational speed, responsive to a stop command signal. An electric motor is deenergized once the rotational speed reaches the predetermined value, and after that the upper drive shaft continues to rotate by inertia. A pulse number to be generated during the inertia rotation will be determined by an inclination of decrease of rotational speed. Another pulse number to be generated during a period when the stop command signal is generated and when the upper drive shaft rotational speed reaches the predetermined value is determined by application of a selective one or combination of prescribed fuzzy rules, so that the upper drive shaft will come to a standstill at a predetermined position or rotational angle, which governs the predetermined position of the needle.

Abstract: A load of an electronic sewing machine is self-diagnosed by a control system to cause a DC motor to be operated under control to drive upper and lower shafts of the sewing machine. The control system includes an evaluating device to which a voltage value applied to the DC motor and a rotating speed of the DC motor, both detected, are inputted for determining a current value supplied to the DC motor and a power loss of the DC motor. These data are supplied to a fuzzy theory applying device for estimating if the power loss of the DC motor exceeds a rated value by application of a prescribed fuzzy rule. A control command signal representing an amount of the excessive power loss is outputted from the fuzzy theory applying device to the DC motor for the control of the applied voltage. No need to directly measure the current value, and therefore no need to provide a current detecting resistor in a control circuit.

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: An embroidering machine is provided with a display section which is retractable within a machine housing and can be pulled to an operational position when in use for select/input operation. Several kinds of select/input operation can be made with a single display means, by suitably changing and selecting the display mode. Select/input operation is made by plotting an appropriate portion seen in the display, reducing to a great extent erroneous operation with a visual support.

Abstract: A current to be fed to a stepping motor for driving is determined by an operating circuit to which are input digital values converted from analog values representing various factors which may affect the stepping motor driving current. The results output from the operating circuit are sent to counters operated in response to a clock pulse signal supplied from an oscillator to thereby generate a pulse-width-modulation (PWM) signal to a stepping motor driving circuit through an output control circuit. The stepping motor driving current may be controlled in dependence on the values of PWL and PWH of the PWM signal.

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: Disclosed is an embroidering system comprising several embroidering machines of known type which will be operated under the operation mode peculiar thereto, and a control unit, to which one or more of the embroidering machines can be connected by a coupling means, adapted to electronically control operation of the embroidering machines connected thereto. When an embroidering machine is electrically connected to the control unit, a signal representing its operation mode is generated from the embroidering machine. The control unit includes a discriminator operated responsive to the signal to discriminate the operation mode of the embroidering machine now electrically connected, whereupon the control unti will be operated to control operation of said embroidering machine in such manner as to conform to the operation mode thereof.

Abstract: A remote-control system is used in combination with a sewing machine for controlling revolution of a sewing machine motor. A remote-controller is connected to a main body of the sewing machine and operated by the sewing machine operator to change a resistance value of a variable resistor contained therein so that the sewing machine motor is driven under control in response to an output volume from the variable resistor. A condensor is connected to said variable resistor and chargeable by a power supply source mounted in the sewing machine main body. The output voltage is converted into a corresponding digital value at each timing when the condensor is saturated with electricity in response to a clock pulse signal at a predetermined interval. The output voltage at such timing will be in proportion to the resistance value of the variable resistor which is, in turn, in porportion to the amount of operation of the remote-controller.

Abstract: An embroidering system comprises a plurality of embroidering machine each connectable to a single control unit. Various characters or patterns are stored in a floppy disc installed in the contol unit, from which pattern data designating a desired pattern combination can be read out and transferred to a memory in the control unit responsive to key entry operation. By repeated key entry operation, plural series of stitch control data including the pattern data are in a lump stored in the memory. Among them, a specific series of the stitch control data can be read out in response to a pattern renewal signal which is generated by manual depression of a corresponding key arranged on the embroidering machine each time when the preceding embroidering operation has been completed.

Abstract: A sewing machine capable of producing embroidery stitches on a workpiece which in general require the workpiece to be shifted relative to a needle in a lateral direction as well as a longitudinal direction. The sewing machine has first and second vertical extending presser bars provided at their lower ends with press rollers. The presser bars are spring-biased downwardly so that the press rollers exert downwardly directing pressure onto the workpiece. First and second feed rollers are arranged within a workpiece supporting table of the sewing machine, in opposition to the press rollers respectively. The first feed rollers are rotated by a first drive motor to feed the workpiece in the lateral direction, whereas the second feed rollers are rotated by a first drive motor to feed the workpiece in the longitudinal direction, thereby feeding the workpiece in any direction in a desired amount.

Abstract: In a wire-dot impact type printer a cylindrical platen and a printing paper are rotated or transported at the same rate, by connecting them to a single and common electric motor through a first and second transmission mechanisms, respectively. The first transmission mechanism directly connects the platen to the motor to cause the former to rotate together with rotation of the latter in any direction, whereas the second transmission mechanism includes a clutch composed of a first and a second members rotatable about a common center axis but separately from each other in which the first member is caused to rotate together with rotation of the motor in any direction while the second member is caused to rotate together with the first member being rotated in one direction but prevented from rotating when the first member is rotated in the other direction. In the latter case the platen is rotated for color changing operation, but the printing paper is prevented from running through the printer.

Abstract: A printer of a wire-dot impact type is provided forwardly of the housing an inlet opening for introducing a printing paper to the inside and has an outlet opening provided at a rear side of the housing for discharging the printing paper to the outside. The printing paper is transported by cooperation of a tractor arranged near the outlet opening and a feed roller arranged near the inlet opening, to thereby run inside the housing in substantially a straight path of travel from the inlet opening to the outlet opening, during which the printing paper is printed by means of a platen and a printing head, both provided between the feed roller and the tractor. A pair of guide members are provided between the feed roller and the printing unit and between the printing unit and the tractor, respectively, to thereby feed the printing paper along the straight path of travel.

Abstract: An electronic pattern stitch sewing machine is disclosed in which stitch control letter pattern data is stored to produce letters in a laterally or vertically readable first orientation and in which stitch coordinate mode changing data is stored to modify the letter pattern data to change the stitch coordinates of the letter patterns thereby orienting the letters in a direction perpendicular to said first orientation.

Abstract: In a zigzag sewing machine a first group of pattern cams is rotated with a predetermined speed relative to a second pattern cam group by the arrangement of a transmission means between the first and second groups. A biasing means normally biases a cam follower to engage a selected pattern cam in said first and second groups. Cam selecting means operate to disengage the cam follower by way of the bias means and slidingly move the follower to a selected position along the cam groups.

Abstract: A paper transporting mechanism is disclosed in connection with a printer having a printing head mounted on a carriage reciprocatingly moved transversely of a printing paper to be printed by the printing head and a platen arranged opposite to the printing head with a clearance being provided therebetween for passing the printing paper therethrough, wherein a first pair of rollers is frictionally rotated to transport the printing paper in the direction toward the printing head and platen, a second pair of rollers is frictionally rotated to transport the printing paper in the direction away from the printing head and platen, a guide is provided between the first and second pairs of rollers, the guide including a first guide plate for guiding the printing paper in the direction toward the printing head and platen and a second guide plate for guiding the printing paper in the direction away from the printing head and platen, the first and second guide plates being integrated to each other to provide opposite inser

Abstract: An electronic sewing machine is operated to produce a stitch pattern or a sequence of plural stitch patterns, in response to corresponding stitch control data, which are stored in an electronic memory element of the sewing machine and read out in response to desired manual operation of a pattern selection device provided therein. The pattern selection device includes an operation panel arranged along a laterally extending bracket arm of the machine housing, on which a plurality of sheet switches for selecting alphabet and symbol patterns in reference to their representations shown on the sheet switches are neatly and efficiently arranged. The sheet switches may comprise two rows of pentagonal shaped switches arranged adjacent to each other, or may comprise three rows in which upper and lower rows comprise sheet switches of pentagonal shape and a middle row of regular hexagonal shaped switches is interposed therebetween.

Abstract: In stitching operation with an electronic sewing machine storing a plurality of stitch control data, a fabric feeding amount for a specific pattern composed of densely arranged zigzag stitches is automatically controlled in a selective one of normal mode and alternate mode. The fabric feeding amount is usually controlled in the normal mode whereby a fabric feeding amount of a predetermined value or a manually selected value is constantly applied to every stitch of the pattern. The normal feed control mode is switched to the alternate feed control mode when the operator selects a fabric feeding amount smaller than a predetermined critical value, in which case the selected pattern composed of densely arranged zigzag stitches is produced with the fabric being fed in an amount double the selected value each time an alternate one of the zigzag stitches is produced.

Abstract: A control circuit of an electronic sewing machine is operated such that, in response to a pulse signal determining the common base stitching line of a selected combination of stitch patterns having different base stitching lines, a corresponding base stitching line control data is read out from an electronic memory for producing the selected combination of stitch patterns in series in reference to the single base stitching line thus determined.

Abstract: A presser foot used in combination with a zigzag sewing machine, which is especially adapted to produce a combination stitch comprising a first half series of stitches and a second half series of stitches formed in the normal feeding direction. The presser foot is provided on the bottom at one side thereof with a recess in the feeding direction for preventing the precedingly formed first half series of stitches from contacting the bottom of the presser foot while the second half series of stitches are being formed.