Abstract: A drive device for a sewing machine which varies the speed of the auxiliary motor. In a sewing machine drive device, the rotation of a clutch motor is transmitted through a pulley and an endless belt to the spindle of the sewing machine. The rotation of an auxiliary motor is transmitted through a driving sprocket, a timing belt and a driven sprocket and through the pulley to the spindle of the sewing machine. The drive device includes rotation varying means which varies the rotation of the auxiliary motor in response to the variation in diameter of the driving pulley of the clutch motor.

Abstract: A sewing machine apparatus and method for sewing a label to a thick, puffy, or quilted mattress is disclosed. The apparatus includes a pair of clamps attached to a carriage, a cutter and nipper disposed above the carriage, and a controller for controlling the sewing machine and carriage.

Abstract: A multiple needle double lock chain stitch quilting machine is provided with an adjustment or calibrating system by which the positions of loopers relative to the corresponding needles of each of a plurality of sets of stitching elements of a ganged array are capable of being precisely set. A control actuator is provided by which an operator, after observing the quality of the product and stopping the machine, actuates an adjustment control system. In response to the a signal from the actuator, a motor precisely advances the stitching mechanism. A sensor monitors the stitching mechanism position, for example, by reading indicia on the needle drive shaft, and generates a position signal when the stitching mechanism precisely in the loop-take-time position of its cycle. A controller stops the motor and activates a brake in response to the position signal locking the mechanism, including the needles and loopers, in the loop-take-time position.

Abstract: A sewing machine having a motor drive operating in response to a controller to rotate in forward and reverse rotation directions. A jogging angle may be set and the drive operated automatically for rotation in forward and/or reverse directions as a function of various operating conditions so that the needle is stopped in an optimum position for piercing a material.

Abstract: This invention relates to a method and apparatus for electronically gearing the sewing parts of a sewing machine, and more particularly it relates to electronically gearing the bobbin to the needle to eliminate the necessity of their physical coupling through mechanical linkages and drive shafts. Servo motors provide torque to the needle, bobbin, and various other sewing parts of the sewing machine which require concerted movement. A computer uses servo motor positional information to calculate motion commands that are sent to the needle and bobbin servo motors, thereby enabling electronic gearing of the bobbin to the needle so that each moves substantially in unison. Motion commands sent to servo motors attached to various other sewing parts of the sewing machine are based on servo motor positional information to enable the sewing parts to move in concert with the needle and bobbin.

Abstract: A detector is provided for a sewing machine wherein light transmitting/shielding discs are mounted coaxially on a shaft of the sewing machine and sandwiched between light receiving and light transmitting optical fibers positioned along opposite side portions of the disc assembly and leading to a processing module section. The detector is able to detect a plurality of positional settings of the sewing machine as well as additional settings without imposing undue stress on the light transmitting optical fibers since the optical fibers remain linear. A power indicating light, connected to the processing module section via an optical fiber, ensures that there is minimal electrical interference with the operation of the detector.

Abstract: A sewing machine stopping control system brings a sewing machine from a high-speed operation to a stop without varying modes and with high stopping accuracy, for allowing the sewing machine to operate highly efficiently. According to the stopping control system, a motor is decelerated in response to a release of a foot pedal. At a time when a predetermined rotational speed or lower is detected, the deceleration operation is disabled regardless of a decelerating command BKON outputted from a speed command comparing circuit. Thereafter, when a predetermined needle position is detected, the deceleration operation is resumed. When a predetermined low speed is detected during the deceleration, the deceleration operation is again disabled. Thereafter, when a predetermined needle position is detected, the deceleration operation is again resumed so that the motor is completely stopped.

Abstract: When a sewing machine is locked during stitching of a thick fabric, the rotational direction of a sewing motor is alternately reversed at a predetermined time interval. A needle operatively coupled to the sewing motor through a mechanical system is moved up and down, whereby the needle sticks into the same stitching point for a desired number of times.

Abstract: A drive arrangement comprises an a.c. induction motor (M1) having a rotary output shaft, and a drive control (FIG. 2), by which the speed of rotation of the shaft is controlled. The drive control comprises a signalling arrangement (e.g. a transducer (T) supplying an analogue signal converted by an analogue-to-digital converter (ADC) or a direct digital signalling arrangement) for supplying a digital signal having a value corresponding to the desired speed of rotation of the motor shaft, together with a processor (CPU) which receives the digital signal and at least one other input and processes the digital signal in accordance therewith. The processor supplies a corresponding, but modified, digital output signal to a digital-to-analogue converter (DAC) which converts the digital output signal to an analogue control signal and supplies it to an inverter which, in response thereto, drives the a.c. induction motor.

Abstract: Circuitry is provided capable of converting input motor speed control signals from one of two sewing machine motor speed switches into output signals adapted to control the speed of a particular type motor used to drive a sewing machine. Values are preset by the user to identify the motor and coordinate the signal conversion accordingly.

Abstract: A sewing machine is provided with an adjusting device for hem projection length sensors that can be moved relative to a cutting device, wherein the first hem projection length sensor is provided for sending a signal that brings about a cutting process for the front hem projection length, and the second of the sensors is provided for sending a signal that brings about a cutting process for the rear hem projection length. The length of the respective hem projection length and the width of an associated seamless fabric edge shall be able to be set depending on each other with minimum operator effort by the adjusting device both at the beginning and the end of the fabric. The adjusting device has a stop that is movable in the direction of feed for the front edge of the fabric for presetting the width of a seamless front fabric edge.

Abstract: A programmable sewing machine is disclosed in which, by means of input elements associated with a control device, the program parts predetermining the operation are selected, connected together and/or linked, the sewing machine being controlled accordingly, and the seams or seam lengths being predetermined by sewn stitches between two points of a material to be sewn and in which as a function of the performance of the stitches predeterminable outputs associated with the control unit are switched. Stitch elements, defined by sewn stitches, and time elements, defined as the time connections between two points of the operation, are interconnected in a random order preselectable by the operator in accordance with the operation. When performing both stitch elements and time elements, outputs can be switched in controlled by the control device.

Abstract: Apparatus for use with an A.C. induction motor drive for a sewing machine to supplant a clutch-brake mechanism by supplying an A.C. induction motor drive to supply power to the motor to control its operating speed and needle position. The control embodies a programmable controller responsive to information loaded into it to derive a profile of how the sewing machine is to operate to sew workpieces, and to generate a control signal which is supplied to the motor drive to operate the motor in accordance with the profile in association with a speed command encoder responsive to a manipulative operator control to produce speed signals to speed up or slow down. The encoder senses the position of the motor and provides a position signal representative of the needle and signals the controller in a closed-loop control system.

Abstract: A position detecting device such as a needle position detecting device which detects a needle position with the aid of a rotor. In the position detecting device, the rotor and a position detecting annular member are abutted against each other, and thus the use of screws can be eliminated, and the annular member can be readily adjusted in angular position with a tool which is inserted through the holes of the rotor and engaged with the adjusting means of the annular member.

Abstract: A sewing machine drive apparatus having a first and second rectifying circuit connected to an AC power source, and a sewing machine control circuit for outputting a drive signal and for outputting a voltage control signal after a certain time period has elapsed from outputting said drive signal. A motor drive circuit is connected to the first rectifying circuit for driving a motor. A DC/DC converter solenoid power source circuit is connected to the second rectifying circuit for outputting a rated voltage of a solenoid, and for outputting a hold voltage to hold the solenoid in response to a voltage control signal. A solenoid drive circuit inputs the output of the DC/DC converter solenoid power circuit in response to a drive signal to drive the solenoid.

Abstract: In a sewing machine, when the depressed condition of a foot pedal is changed from a forward depressed condition for high speed sewing to a reverse depressed condition for thread cutting, a braking circuit decreases the rotational speed of the machine motor from a high speed to a low speed. The rotational speed is detected by an encoder. When the rotational speed detected by the encoder becomes a threshold medium speed or less, and a needle-down signal is generated from a needle position detector, the CPU of the sewing machine outputs a work fabric feed pitch control start signal to a work fabric feed pitch selector. The work fabric feed pitch selector reduces or nullifies the feed pitch of the work fabric. Under this condition, in response to the next needle-down signal, the CPU operates a thread cutting mechanism to cut the needle and bobbin threads.

Abstract: A sewing machine-driving apparatus forms an accurate and stable seam at a first stitch in a conventional double chain stitch or covering chain stitch sewing machine. Its motor is controlled so as to drive the sewing machine in a direction reverse to that of the usual sewing operation for a limited time period between the completion of a thread cutting operation and a point of time when the sewing machine needles reach their needle-down position. Thus, the stitching needles reach their lowest points without scooping a looper thread at the first stitch; assuring the formation of a stable and accurate seam in the second stitch.

Abstract: A control device for sewing machines which includes a drive system controller which controls each of numerous driving units provided in the sewing machine and which is connected to an optional command system controller that is positioned outside of the sewing machine. Thus, a control code from the outside command system may be input and decoded to control the drive system controller.

Abstract: A sewing machine having separate drives for the needle bar and looper includes initialization routines to place the needle bar and looper in predetermined starting positions prior to the start of a sewing operation. Position detectors comprise photoelectric cells and interrupters mounted on the motor shafts of the needle bar drive motor and the looper drive motor. The position of the needle bar is initialized first, by movement in a reverse direction, if necessary, to prevent undesired engagement with the looper. Thereafter, the looper position is initialized. A sewing operation is enabled once the needle bar and looper are set in predetermined starting position.

Abstract: The control pedal (7) for an electric machine (3) comprises a movable member (9) connected to a foot support (11) and adapted to be actuated by the foot of the user, whose heel rests on the plate (10). When the pedal (7) is not in use, the member (9) may be lowered against the plate (10), whereas the cord (8) and that which is provided for the plug (6), are wound about the portions (12) forming bobbins.

Abstract: A processing and sewing machine arrangement for preparing a seam which is uninterrupted on a seam side facing the needle of the sewing machine. The arrangement includes a shuttle thread disturbance detection arrangement and a control arrangement activating a stopping arrangement for stopping the sewing machine after the shuttle thread disturbance has been detected and after a stitch formation cycle which has been begun is completed. A regulating mechanism for setting stitch length is set into a reverse stitching mode by the control arrangement while the fabric being sewn is moved backward by one stitch length. After the shuttle thread has been fed in, thread is knotted by at least one stitch with the needle thread in the same insertion hole in which the old shuttle thread is located such that the old shuttle thread is correctly knotted with the needle thread.

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: 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 stitch controller for installation on an electric sewing machine with a treadle and a needle positioner to make the machine semi-automatic. The controller has a CPU which directs, by means of a program in its memory, the machine through a defined number of stitches in a run of stitches and a defined number of runs of stitches. Additionally, the CPU will direct the needle position to up or down according to the program.

Abstract: A sewing machine rotates a motor in reverse direction through a predetermined angle for giving an impetus to a needle to penetrate a thick and heavy cloth when a time period from starting of sewing to a completion of a first stitch is longer than a predetermined time period.

Abstract: A multifunction switching control system includes: a sewing speed controller of a computerized sewing machine controlled in response to a voltage of a sliding terminal of a variable resistor incorporated in the controller; an invariable resistor; a first A/D converter for converting the voltage from an analog signal to a first digital signal; and a second A/D converter for converting a voltage at a fixed terminal of the variable resistor from an analog signal to a second digital signal. A switch circuit for directly connecting one terminal of the invariable resistor to the fixed terminal of the variable resistor is provided in the controller. By comparing the second digital signal with a preset value, it is determined whether or not the switch circuit is so operated. In case that the switch circuit is so operated, sewing operation other than sewing speed controls of the machine are conducted.

Abstract: An edge tracing sewing machine includes a reciprocable needle bar having a needle at a lower end, a needle position sensor for detecting needle-down position, a presser bar having a presser foot at a lower end, a presser foot switch for detecting an upper position of the presser foot, a vertical feed driving device, a forward feed driving device for feeding a work fabric in a sewing direction, a lateral feed driving device for feeding the work fabric in a lateral direction perpendicular to the sewing direction, a fabric-edge position detector, a tracing width setting device, and a control device. The control device controls the lateral feed driving device based on signals from the fabric-edge position detector and the tracing width setting device, so as to carry out a tracing sewing with the tracing width set by the tracing width setting device.

Abstract: An edge tracing sewing machine includes a reciprocable needle bar having a needle at a lower end, a forward feed driving device for feeding a work fabric in a sewing direction, a lateral feed driving device for feeding the work fabric in a lateral direction perpendicular to the sewing direction, a tracing width setting device for setting a tracing width from the edge of the work fabric to the needle in the lateral direction, a fabric-edge sensor movable in the lateral direction for detecting an edge of the work fabric, a fabric-edge position detector for detecting a position of the fabric-edge sensor, and a control device. The control device moves the fabric-edge sensor in the lateral direction to make the fabric-edge sensor follow the edge of the work fabric. The control device controls the lateral feed driving device based on the tracing width set by the tracing width setting device and the position of the fabric-edge sensor detected by the fabric-edge position detector.

Abstract: An edge tracing sewing machine includes a reciprocable needle bar having a needle at a lower end, a needle position sensor for detecting needle-down position, a presser bar having a presser foot at a lower end, a presser foot switch for detecting an upper position of the presser foot, a vertical feed driving device, a forward feed driving device for feeding a work fabric in a sewing direction, a lateral feed driving device for feeding the work fabric in a lateral direction perpendicular to the sewing direction, a fabric-edge position detector, a tracing width setting device, and a control device. The control device controls the lateral feed driving device based on signals from the fabric-edge position detector and the tracing width setting device, so as to carry out a tracing sewing with the tracing width set by the tracing width setting device.

Abstract: One of a plurality of photoelectric detector plates are mounted on a coupling fixed to an arm shaft of a sewing machine, and have predetermined light shields. A light-emitting means is disposed on one side of the photoelectric detector plates for emitting light toward the photoelectric detector plates, and a photodetector means is disposed on the other side of the photoelectric detector plates for receiving the light emitted from the light-emitting means. Conditions of the sewing machine can be detected by the manner in which the photodetector means receives the light.

Abstract: An electronically controlled sewing machine, comprises a current detecting device for detecting a value of current flowing through a stepping motor that drives a machine part and current setting means for setting a value of current to be applied to the stepping motor. The sewing machine further includes a control device (CPU) for storing a plurality of different values of currents to be applied to the stepping motor and driving the stepping motor until the stepping motor passes through an initial position thereof. The control device stops the stepping motor at a predetermined angular position thereof spaced from the initial position. The control device supplies the different values of currents to the stepping motor in a predetermined sequence from a smallest value to a larger value of current under a predetermined program to drive the stepping motor until the stepping motor reaches the initial position thereof.

Abstract: By means of this method and apparatus for sewing a seam, it is possible to end a seam exactly at a predetermined location. When the predetermined location is reached, the forward movement of the sewing material is interrupted, and only the stitch that had been begun at the time of the interruption is completed. In this way, on the one hand, visually attractive seams can be produced and, on the other hand, it is possible to sew a small part onto a main part with a seam which does not extend past the small part.

Abstract: A device for sewing the edges of a mattress contains a movable supporting face, a sewing mchine, and a swingable arm cooperating with holding means for swinging the mattress around one of its corners. Furthermore, sensors for sensing the position of the mattress are provided, as well as a control device for activating the swingable arm, dependent on the signals issued by the sensors. The control device also contains counting devices and memory elements for automatically stitching one complete edge of a mattress.

Abstract: In a sewing machine, immediately after every thread trimming, the electric motor is reversely rotated for a predetermined angle, hence reversely rotating the sewing mechanism, so that the needle bar is brought up to its upper dead point when the electric motor is stopped after the thread trimming, and, thereby, there is no fear of spoiling the object cloth by the needle tip. The predetermined angle is controlled by processing an output signal of a speed detector.

Abstract: A sewing machine and a method of controlling operation of the same wherein reading out of a selected finish-up stitch pattern is effected substantially simultaneously with generation of rotation speed reduction signal when an actual rotation speed of the machine is lower than the reference rotation speed, and when a rotation speed is reduced to the reference rotation speed upon the actual speed of the machine being higher than the reference rotation speed.

Abstract: An electric motor of a sewing machine may be stopped naturally at an objective position by amending the amount of the motor's running errors as overrun or underrun with respect to the stop objective position without employing an especially forceful stopping circuit in spite of dispersions in a load inertia caused by mass-production of sewing machines or variances in loads during driving of the sewing machine.

Abstract: A two needle sewing machine having a one needle pause function wherein a needle thread supply device is provided. The needle thread supply device includes a thread guide element. The thread guide element is reciprocally movable in association with a drive means to change the length of the thread path for controlling the tension of the thread.

Abstract: One or a plurality of photoelectric detector plates are mounted on a coupling fixed to an arm shaft of a sewing machine, and have predetermined light shields. A light-emitting means is disposed on one side of the photoelectric detector plates for emitting light toward the photoelectric detector plates, and a photodetector means is disposed on the other side of the photoelectric detector plates for receiving the light emitted from the light-emitting means. Conditions of the sewing machine can be detected by the manner in which the photodetector means receives the light.

Abstract: A sewing machine control device equipped with an operating switch (10) for instructing the sewing machine to operate and stop by turning on and off the operating switch (10) and a counter (9) for accumulating the duration of a running signal (SRT) produced while the operating switch is in an on state, so that the actual accumulated (total) operating time during which the sewing machine is actually operated can be obtained accurately from the accumulated (total) duration of the running signal (SRT).

Abstract: A tufting machine having a mainshaft rotatably driven by one or more A.C. motors reciprocably drives a needle bar carrying a multiplicity of needles. Two brakes are associated with the shaft, the first brake being actuated when the motors are deenergized, and the second brake is actuated after the speed of the shaft has been reduced to a predetermined speed which permits the shaft to be stopped with the needle bar and the needles at the top of the reciprocating stroke. The motors may also be gradually started so that attainment of full speed is not reached until after the expiration of a predetermined time interval. Thus, "stop marks" may be substantially eliminated.

Abstract: An apparatus for terminating the last stitch at a predetermined point including two workpiece-end detectors, one working to reduce the stitching speed and the other working to terminate the last stitch at the predetermined point with reduced speed. Where the number of stitches (D) to be conducted at the reduced speed exceeds number of stitches (R) necessary to reduce the speed, stitching without reducing speed continues and the number of stitches is operated as (D-R), and then the speed is reduced. Thus, stitching speed is increased. The above processes are automatically conducted through a CPU (Central Processing Unit) by input of the necessary data, namely, the original stitch pitch (P), the margin distance (a), the number of stitches (R) necessary to reduce speed, etc.

Abstract: A sewing machine adapted for moving a workpiece in a downstream direction for sewing a seam therein, and for automatically terminating the seam at a predetermined point a selected distance from a trailing edge of the workpiece. An edge sensor on a base is located a predetermined distance upstream of the sewing point for sensing the downstream passage of the trailing edge, and generating edge sensing signals in response thereto. A stroke sensor on the base senses the length of the strokes of the feed dog and generates stroke length signals which are indicative of the stroke length and of the length of the stitches.

Abstract: A walking needle chain stitch sewing machine having multi sewing heads laterally spaced apart from one-another, that includes upper primary drive shaft and secondary lower first and second drive shafts and mechanisms thereof for driving first and second needle-drive mechanisms, and that further includes other secondary lower third and fourth drive shafts and mechanisms thereof for driving first and second feed-dogs and mechanisms thereof, with the first and second drive shafts being connected to the primary drive shaft by respectively spaced-apart drive-belts each mounted between driving and driven gears, and with the third and fourth drive shafts likewise being connected to the primary drive shaft by respectively spaced-apart other drive-belts each mounted between other driving and driven gears.

Abstract: A multineedle automatic sewing machine has a needle holder which is vertically movable above a needle plate. The needle holder has needles which are supplied with upper threads unwinding from spools, and with shuttles which contains spools with lower threads. The shuttles are arranged on horizontally displacable shuttle holders below the needle plate. Each shuttle contains an electric circuit in which the shuttle, together with an associated contact plate, is arranged on the lower side of the needle plate, functioning as an electric switch so that the machine is switched off in the case of the breaking of one single lower thread.

Abstract: A servo device for a multineedle sewing machine which includes two needle bars; driving and steop devices for said needle bars; devices for engaging and disengaging the two needle bars relative to the driving and stop devices; a feed-length adjustment device associated with at least one feed dog for the transport of the material being sewn; an adjustable thread tensioning device for the needle threads; devices for locking each needle bar selectively in its highest position; a positioning drive for the multineedle sewing machine; and a device including a position indicator attached to an arm shaft of the multineedle sewing machine, for adjusting the speed of rotation and positioning of the needle bars in predetermined positions.

Abstract: In a drive for a sewing machine, especially an industrial sewing machine, with a needle that can be reciprocated between an upper and lower end position by a sewing machine main shaft, in which the drive is in direct driving connection with the main shaft and can be controlled at variable speed through a control system, provision is made for improving the dynamic performance of the combination of drive and sewing machine by equipping it with at least one input switch connected electrically to the control system for the input of command pulses for the step-wise actuation of the drive such that with each command pulse a certain, defined amount of movement of the drive and hence of the main shaft is triggered.

Abstract: In a sewing machine equipped with an apparatus to terminate stitching at a predetermined point, the machine normally does not terminate stitching exactly at the desired predetermined point because the elastic nature of the workpiece causes the workpiece to stretch. A last stitch is added beyond the point where stitching terminates by the "step sewing" apparatus of this invention. To perform step sewing, an operator inputs a stitch pitch for step sewing with a digital switch, then pushes a step sewing button. Based on the selected stitch pitch, a CPU reads selected stitch pitch data. The data is used by the CPU to control a stitch pitch setting mechanism. A stitching device then performs a single stitch at the selected stitch pitch. By selecting the proper stitch pitch, the last stitch can terminate at the desired termination point.

Abstract: A motor control apparatus for a sewing machine comprising a stop device for generating a stop signal instructing stoppage of an alternating current motor, a sensor for sensing a predetermined position of a needle and outputting a position signal thereof, and a stop control responsive to the stop device and the sensor means for controlling a rotating field of an alternating current motor to stop in response to the stop position of the needle when the stop signal and the position signal are received.

Abstract: A flat touch switch having plural switch components with rotation speeds of the sewing machine shaft indicated on each component is positioned in the region of the needle bar. Pushing a component part of the switch drives the machine at the indicated speed. A control logic circuit senses the pushed component and by sensing the speed of the driven shaft, drives the machine at the selected speed.

Abstract: This invention relates to a sewing machine control device which precisely and effectively stops a sewing machine at the termination point of a seam. The sewing machine control device comprises operation means (LSW) for producing an actuation signal or a stop signal, needle position detector means (NP), workpiece detector means (5, WS) operatively connected to said operation means and an electrical circuit operatively connected to said workpiece detector means. When the operation means drives or stops the sewing machine and the workpiece detector means detects the trailing end edge of a workpiece, the electrical circuit automatically stops the sewing machine.