Abstract: A pattern sewing machine provided with a thread trimmer and a thread delivery unit. After a series of patterns is completed and the thread trimmer trims thread, the thread delivery unit is prohibited from delivering thread until the next sewing operation starts to form another pattern. When the patterns are distant from each other, a needle bar is disconnected and fabric is fed a distance in a non sewing operation. No excess thread is delivered corresponding to the feeding distance of the fabric, thus preventing thread from being wasted. Furthermore, an operator can avoid the cutting of excess thread with scissors. The sewing efficiency is thus enhanced. In the pattern sewing machine the crossover thread connecting the patterns is automatically cut regardless of the distance between the patterns.

Abstract: In the pattern sewing machine comprising a pattern selector for selecting and combining pattern units such as characters and symbols and a controller for driving a sewing mechanism and a feeding mechanism to form the combination of pattern units selected by the pattern selector, the controller is provided with a diagonal placing unit for placing one pattern unit in a diagonal direction relative to another pattern unit adjacent thereto when the two adjacent pattern units are sewn in series.

Abstract: A zigzag sewing machine comprising a needle bar lateral drive device, a needle bar lateral drive steppping motor for controlling the needle bar drive device, a feed device for driving a feed dog back and forth, a crossfeed device for driving the feed dog from side to side, and a crossfeed stepping motor for controlling the feed drive device. The sewing machine can sew beautiful pattern stitches and neat stitches by setting up amplitude according to the minimum feeding pitch of the feed dog which is smaller than the minimum moving pitch of the needle bar. Since the needle location is determined by cooperation between the needle bar and the feed dog, the maximum lateral moving width of the needle is shorter than amplitude and the needle can be securely and accurately driven even at a high sewing speed.

Abstract: A zigzag sewing machine comprises a pattern data memory, a fixing stitch memory, a read-out unit, a controller, a determination unit, a switch-over mechanism and a stitch forming mechanism. The read-out unit reads out pattern stitch data from the pattern data memory means. Based on the read-out stich pattern data, the controller controls the stitch forming mechanism to form a pattern on a fabric. If a repeat sewing mode is selected, the controller repeatedly sews the pattern. Meanwhile, the determination unit determines if a given pattern whose sewing is in progress is a predetermined last pattern or a pattern which was not initially designated as a last pattern but was later redesignated as a last pattern by mode switching.

Abstract: A stitch pattern sewing machine includes a ROM for storing triple stitch pattern data for a large size pattern and single stitch pattern data for a small size pattern for each pattern of a plurality of patterns, a pattern selecting unit for selecting one of the patterns, an enlargement switch for enlarging a size of the pattern selected by the pattern selecting unit, a reduction switch for reducing the size of the pattern selected by the pattern selecting unit, a CPU, and a driving unit for forming a stitch. The CPU selects one of the triple stitch pattern data and the single stitch data based on size of the pattern. The CPU controls the driving unit based on the selected pattern data and size of the pattern. As a result, stitch thickness can be varied with pattern size to maintain a desired appearance.

Abstract: In the sewing machine of this invention, the operator can confirm on the selected-mode display M9 provided in the display M4 that the selected mode is for writing the pattern and whether the selected pattern is for only one use or the selected pattern is to be stored in the nonvolatile storage M7. The pattern selector M2 selects at least two patterns from the pattern-data storage M1. The arrangement of the selected patterns is stored in the pattern storage M3. The stored arrangement of the patterns is stored in the nonvolatile storage M7. Through specified processes, the patterns reader M8 develops the arrangement of the pattern stored in the nonvolatile storage M7 into the pattern storage M3. The controller M6 sequentially reads the arrangement of the patterns developed in the pattern storage M3 and drives the sewing mechanism M5 to form the arrangement of the patterns on fabric. When the pattern to be used repeatedly is thus once entered, the pattern can repeatedly be stitched on fabric.

Abstract: A sewing machine for forming successive stitches along an edge of a workpiece, including an endwise reciprocable sewing needle, a feeding device for feeding the workpiece in a feed direction, in synchronization with reciprocations of the needle, a control motor for changing a relative position between the needle and the workpiece in a lateral direction perpendicular to the feed direction, an edge sensor generating an output signal corresponding to a position relative to the workpiece edge in the lateral direction, and a position control device for receiving the output signal from the sensor in synchronization with the needle reciprocations and applying to the control motor a drive signal to control the relative position between the needle and the workpiece edge. The drive signal is determined based on the output signal of the sensor.

Abstract: A sewing machine having an edge sensor for detecting an edge of a workpiece in a lateral direction perpendicular to the workpiece feed direction, and a tracing control device for controlling a relative position between a needle and the workpiece in the lateral direction to form stitches along a line a predetermined distance away from the workpiece edge. A motor to change a relative position between the workpiece edge and the sensor is operated from a first limit position to a second limit position to obtain first output signals of the sensor, and an average of a maximum and a minimum value of the first output signals is calculated. The motor is then operated from the second limit position toward the first limit position to obtain second output signals of the sensor. A first and a second average position signal are determined such that the average position signals correspond to the average value of the maximum and minimum values of the first output signals.

Abstract: In order to correct the asynchronous state of a feed pulse motor of a sewing machine used to reciprocate a feed for feeding a fabric to a sewing needle, a feed control apparatus is provided which switches the pulse motor to a predetermined excited state when the feed dog abuts a stopper on the downstream side of feed motion at the start up of sewing operation so as to locate the feed dog at a known reference position. Additionally, the feed control apparatus switches the pulse motor to another predetermined excited state when the feed dog abuts a stopper on the upstream side of the feed motion so as to locate the feed dog at a known position during consecutive sewing operation.

Abstract: The start and end timing of fabric feed in a sewing machine greatly affects the tightening of needle thread, that is, the sewing quality. Among the electronically controlled zigzag sewing machines, those equipped with feed means directly driven by a pulse motor supplied with command pulses, it has become possible to control freely the start and end timing of fabric feed.

Abstract: A zigzag sewing machine capable of forming a plurality of back stitches before or after forming a pattern. When a specific pattern for over-casting is selected and the needle is jogged to a position corresponding to the right end position of the selected pattern, back stitches are formed after the needle has been jogged to the left in response to the operation of a back stitch control member.

Abstract: A feed device has feed members for feeding a work, and a stepping motor for directly driving the feed members. The period of driving pulses for driving the stepping motor is determined by feed control means on the basis of a speed signal indicating an actual operating speed of the main motor of the sewing machine or on the basis of a selectively set speed. The feed control means controls the stepping motor so that the feed motion of the feed members is continued also after the completion of the thread tightening operation of the take-up lever in order that the needle thread is tightened properly by the feed motion of the feed members.

Abstract: A feed device drives a feed dog directly by a stepping motor having a predetermined number P of excitation modes, and devised so that the output shaft thereof is turned by a unit amount S when the excitation mode is changed over. A stopper is disposed so as to define the range of the horizontal feed motion of the feed dog. An excitation control means excites the stepping motor in a specific excitation mode at the start or at the end of horizontal feed operation. The specific excitation mode is one of the excitation modes in which the stepping motor is excited while the output shaft thereof is turned by an amount P.multidot.S/2 from a position where the output shaft of the stepping motor is restrained from rotation by the stopper.

Abstract: An electronic sewing machine capable of sewing a buttonhole having a circular stitching part. The machine is operative selectively in one of automatic and manual modes. In the automatic mode, bight position of a needle and feed position of a feed dog are automatically controlled according to stored bight and feed data. In the manual mode, the bight and feed positions determined by the stored data are adjusted by a data adjusting circuit. The machine comprises a circuit which supplies the data adjustment circuit with a signal to inhibit the adjustment of at least the feed data for each stitch to be formed in the circular stitching part.

Abstract: A sewing machine aurally informs an operator of abnormal conditions which accidentally have taken, or are taking, place by means of a vocal indication. One group of speech data corresponding to an accidentally occurring abnormal condition is selected from among plural groups of speech data according to a detection signal from a plurality of abnormal condition detectors disposed in the machine. A voice signal corresponding to the selected group of speech data is generated in relation to operation of a manual device e.g. a button such as a switch, for the start of sewing. The operator can hear the warning voice due to this vocal indication simultaneously with the operation of the manual button for the start, whereby he/she is prevented from starting of the machine while the abnormal condition exists.

Abstract: An electronic sewing machine capable of forming a buttonhole having a circular stitching part. The machine has manually operated members for setting thread thickness and button size. A stitch data generator is provided, which is capable of selectively generating one of plural different groups of stitch data for forming different buttonholes which have a different number of stitches at their circular stitching part. The specific group of stitch data is selected according to code signals fed in accordance with the positions of the manually operated members. The position of each stitch contained in the circular stitching part of the buttonhole is determined by each stitch data of the selected group. Thus, the desired buttonhole is sewn neatly without crowded or lean stitches.

Abstract: A diagnostic table which stores possible causes of certain abnormal conditions is accessed by corresponding push buttons for sequential vocalization by a sewing machine system, thereby helping the operator check the machine.

Abstract: A buttonhole sewing machine for automatically forming a buttonhole including right and left parallel side stitching parts, and another stitching part connected to the side stitching parts. The machine has a switch for detecting front and rear ends of each side stitching part, and is capable of sewing the buttonhole in divided parts on opposite sides of a longitudinal centerline thereof so that the two side stitching parts are stitched in the same work feeding direction. The machine comprises a control circuit generating a feed change signal when the number of stitches being formed in one of the side stitching parts has become equal the total number of stitches of the other side stitching part less a predetermined number, and a feed adjusting circuit for reducing a work feeding increment for a time interval between generation of the change signal and a signal from the switch, to avoid a difference in length between the side stitching parts.

Abstract: An electromechanical actuator is formed in flat and thickness reduced configuration having a stator, a movable portion to drive or control a needle positioning mechanism and a work feed regulating mechanism or the like in response to electrical signals. Said stator portion includes a pair of parallel spaced yokes to define a single air gap therebetween, and a plate-like permanent magnet secured to an inner wall of at least one of said yokes, the magnet being magnetized so that oppositely directed flux fields are established within the air gap. Said movable portion includes planar armatures disposed in said flux fields to pivotally move with the fulcrums placed at the opposed peripheral portion, and exciting windings each carried by said armatures.

Abstract: An automatic thread regulating system having an adjustment mechanism for controlling the thread feed and takeup during the formation of a sewing machine stitch. A central processing unit calculates the length of thread required for a specific stitch formation based on work piece thickness and stitch length. This information is directed to the adjustment mechanism which thereby regulates the appropriate thread amount by feed rolls and a suction apparatus.