The Singer Company

Philip F Minalga

John W Wurst

Kenneth D Adams

John A Herr

Wolfgang Jaffe

Charles R Odermann

Robert H Larsen

Allan M Dob

William L Herron

Robert B Brauch

William J Edwards

William H Dunn

Edward A Salge

For a family sewing machine having the capabilities to complete a buttonhole in a single step, an arrangement is provided to permit an operator to reinitiate the buttonhole operation in the event of a thread breakage in the middle of the buttonhole, however, without necessitating stitching during that part of the buttonhole in which stitching has already been implemented. If a thread breakage takes place and after repair thereof the buttonhole may be repositioned to the initiating position and the buttonhole pattern may be reselected together with, for example, a selection of reverse feeding or any other input which is not normally selected during buttonholing. This dual selection is effective to signal the needle bar release logic to suspend endwise reciprocation of the needle bar. The sewing machine feed proceeds as though stitching were taking place, and just before the point of thread breakage is reached the needle bar release logic can be defeated so that stitching may proceed from a point one or two stitches prior to the point of breakage.

Buttonhole sewing repair

A spool pin holder for accommodating deflection of a spool pin wherein a spherical segment adjacent the ends of the spool pin is seated in a socket in a spool pin post adjacent a socket of square profile having grooves extending along the diagonals of the square beyond the square so as to accommodate therein a first pair of leaf springs in a first diagonal on either side of a spool pin end and a second pair of leaf springs in the second diagonal about the spool pin end adjacent the first pair so as to provide a restoring force to the spool pin in response to any disturbing force displacing the same.

Spool pin holder for a sewing machine

An electronically controlled sewing machine includes an arrangement for utilizing the feed override control to effect a feed balancing function for a pattern having both directions of feed. To effect the balancing function, those patterns which have both forward and reverse feed are 'flagged' for recognition by the sewing machine control system. When such a pattern is being sewn, the function of the feed override control is changed to perform the balancing function. Accordingly, when the feed override control is enabled, a fixed increment is added to all forward feeds in the pattern and the feed override control is utilized to attenuate only the forward feeds, to effect a balanced condition.

Pattern feed balancing arrangement in an electronically controlled

A linear motor is used to jog the needle bar and gate beyond the normal jogging range in order to disable a latch and separate the needle bar from the sewing machine driving means. The linear motor is driven into this abnormal excursion beyond the usual jogging motion by supplying a known needle position signal to the servoamplifier system for the linear motor and providing a separate voltage from a regulated voltage source which is summed with the specific signal in order to provide sufficient electromotive force for jogging the sewing needle beyond the normal jogging range.

Basting stitch overthrow system

An arrangement in an electronically controlled stitch pattern sewing machine which detects when the sewing machine is operating at speeds above a predetermined speed and when this is the case, instead of utilizing the bight synchronization signal generated by the armshaft timing pulse generator, the arrangement calculates a speed dependent time interval after the feed synchronization pulse so as to begin processing the bight data at some time prior to the bight synchronization pulse.

Data advancing arrangement in a sewing machine

A system is disclosed for positioning an instrumentality over a predetermined range in response to a digitally coded position signal. To effect a controlled reduction in the instrumentality movement, an operational amplifier is provided having a feedback circuit including a fixed resistor and a controllable switch connected across the resistor. The switch is selectively controlled to short circuit the resistor at a controlled rate to effect a controlled gain reduction for the operational amplifier.

Digitally controlled gain reduction in a positioning system

A system is disclosed for positioning an instrumentality over a predetermined range in response to a digitally coded position signal. To effect desired adjustments between digitally achieved positions, algebraically adjustable signals are subtracted from an analog position signal obtained from the digitally coded position signal.

Analog adjustment arrangement in a digitally controlled positioning

In an electronically controlled sewing machine, new stitch position coordinate information is retrieved from a solid state memory and transferred to the sewing machine servo system one bit per some proportional clock period, at either a fast stepping rate or a slow stepping rate depending upon the speed of the sewing machine. By use of suitable logic gates, a low speed condition will initiate a slow stepping rate of some fraction of a predetermined clock period, whereas a high speed condition will initiate a fast stepping rate of once every clock period. The new data from the solid state memory is fed to a comparator wherein it is compared to the immediately prior stitch position coordinate information transferred to the servo system and retained in an up/down counter. The comparator determines whether the new data requires an up or a down count of the counter. The signal from the up/down counter is transferred to a pulse width modulator, the output of which is fed to a digital to analog converter for the appropriate bight or feed servo system of the sewing machine. In effect, the pulse width modulated signal transferred to the servo system is a ramp signal of steep or shallow slope dependent on whether the sewing machine is operating above or below a predetermined speed.

Sewing machine input signal waveshaping

A sewing machine is disclosed in which electromechanical actuators are incorporated. By selectively supplying power to position the electromechanical actuators, the stitch forming instrumentalities of the sewing machine may be operatively controlled. In order to reduce heat dissipation within the sewing machine under abnormal conditions where the actuators are locked for long periods of time, the sewing machine main drive motor motion is monitored. After a predetermined period of inactivity of the sewing machine main drive motor, the power which can be supplied to the actuators is limited.

Power limiting arrangement in a sewing machine

The present disclosure relates to zig-zag sewing machines including means for controlling the bight stops in order to produce ornamental patterns. In particular, the disclosure relates to electronically controlled sewing machines having storage means for storing stitch information and wherein logic means are used to select and release stitch information in timed relation with the operation of the sewing machine. The disclosure of the invention has particular application in those sewing situations wherein it is desired to use more than one needle in a single needle holder of the needle bar which therefore necessitates a limitation on the magnitude of the jogging or swinging of the needle bar in order to accommodate the multiple needles in the aperture of the needle plate. In accordance with the disclosure of the present invention whenever more than one needle is used in the sewing machine the electronic control of the bight stops is automatically put into effect whenever such multiple needle mode is selected.

Bight stop mechanism for sewing machines

An improvement in a logic controlled sewing machine which permits an operator to vary by electronic means ornamental pattern bight and feed, manual stitch control, or individually control forward and reverse feed to achieve, for example, an optimum balanced buttonhole or ornamental variations to patterns. Operator influenced means are effective to signal the logic to apply a holding signal to FET switches, maintaining the FET switch in the conductive state. Closing of the FET switch inserts the wiper of a rheostat in bypass arrangement in the feedback circuit of an operational amplifier between a digital-to-analog converter for feed or bight and, respectively, a feed or bight servo amplifier system. By changing the magnitude of the resistance in the feedback circuit of the operational amplifier, the gain may be altered, thereby to control the signal to the feed or bight linear actuator for variation of stitch length or pattern width, respectively. An additional FET switch is maintained in the conductive state by the logic means only during reverse feed thereby applying a variable voltage to a summing point prior to the servo amplifier for exclusive control of reverse stitch length during pattern stitching.

Electronic control of bight, feed and feed balance in a sewing machine

A linear motor for use, for example, in sewing machines for controlling needle vibration as to amplitude and/or fabric feed both in magnitude and direction, said motor comprising a frame having an internal central pole piece spaced intermediate two permanent magnets of the high energy product type which are attached to the frame, the central pole piece providing supporting means for movable coil member integrally formed with connecting arms pivotally fastened to an actuator arm carried on a pivoted potentiometer shaft. The permanent magnets are secured through their own magnetism to the frame and are each locked in proper orientation by a non-metallic retainer which is locked to the magnet and additionally formed with a closure panel, said closure panels cooperating with the motor frame completely to enclose a compartment for the movable coil member effecting both a minimum external leakage field and a dust proof unit.

Linear motor

A system is disclosed for a sewing machine in which preselected stitch patterns may be formed automatically. Information related to the positional coordination of the needle penetration for each stitch of each pattern is stored in the sewing machine. Logic means are used to select and release said stitch information in timed relation with the operation of the sewing machine. The selected information is converted to positional analog signals which control closed-loop servo means including a moving-coil linear actuator which directly controls the position of conventional stitch-forming instrumentalities of the sewing machine to reproduce a pattern of stitches corresponding to the selected stitch information.

Growing community of inventors

Piscataway, NJ, United States of America

Philip F Minalga