US3727567A

US3727567A - Automatic sewing apparatus

Info

Publication number: US3727567A
Application number: US00123534A
Authority: US
Inventors: A Beazley
Original assignee: Farah Manufacturing Co Inc
Current assignee: Farah Manufacturing Co Inc
Priority date: 1969-08-19
Filing date: 1971-03-12
Publication date: 1973-04-17
Anticipated expiration: 1990-04-17

Abstract

An automatic sewing apparatus is provided which sequentially controls the positioning and sewing of workpieces. Position of a workpiece is sensed by two photoelectric cells which activate portions of an electrical control circuit to control the various apparatus functions. Workpiece orientation is maintained by several guide means which interact with the sewing machine. An extendable rod turns the workpiece about the sewing machine needle thereby permitting several lines of stitching on a single workpiece.

Description

United States Patent 1 1111 3,727,567

Beazley 51 Apr. 17, 1973 I541 AUTOMATIC SEWING APPARATUS 2,940,404 6/1960 Damon 112/121.15 x

3,097,733 7/1963 Frydryk... ..112/121.1s x

[75] Inventor Aubmy Beazley El P850 3,232,256 2/1966 Buckalter.... ..112/121 15 Assignee; Farah Manufactu Com 3,335,682 8/1967 TUCCi 112/121 15 Paso Tex. 3,386,396 6/1968 Jacobs et a] ...112 121 12 3,434,439 3/1969 Winberg 112/121 12 [22] Filed: Mar. 12, 1971 3,517,630 6/1970 13666156661311. ..112/121.12 12 1 Appl. No.: 123,534

Related US. Application Data Continuation-in-part of Ser. No. 85l,303, Aug. l9,

1969, Pat. No. 3,589,320.

References Cited UNITED STATES PATENTS Millhiser et a1 ..112/10 X Millhiser et a1 12/10 Primary Examiner-James R. Boler Attorney-Curtis, Morris & Safford [5 7] ABSTRACT An automatic sewing apparatus is provided which sequentially controls the positioning and sewing of workpieces. Position of a workpiece is sensed by two photoelectric cells which activate portions 'of an electrical control circuit to control the various apparatus functions. workpiece orientation is maintained by several guide means which interact with the sewing machine. An extendable rod turns the workpiece about the sewing machine needle thereby permitting several lines of stitching on a single workpiece.

13 Claims, 15 Drawing Figures PATENTEI] APR 1 H975 SHEET 01 DF 11 O N ill I 0 Q Q Q 39 I 1 Q\ SQ; Q 1: a) W) g Mm Q Q 0 Q t\ Q a u) 5 0 ,"Q c k) Q d o A a t]:

( 1 uni 1 bmvENToE LL re e 443% axle I M & ATTORNEYS PATENTEDAPR 1 71973 sum 05 [1F 11 IT-NA PAIENTEDAPR 1 71973 3,

SHEET 08 0F 11 PATENTEBAPR 1 71975 sum 09 [1F 11 Amy m .r mW 5:18 a mum a SHEET 11 [1F 11 mmNNsm PATENTEB APR 1 H975 AUTOMATIC SEWING APPARATUS This application is a continuation-in-part of copending application Ser. No. 851,303 filed on Aug. 19, I969 and now US. Pat. No. 3,589,320 issued on June 29, I971.

This invention relates to an automatic sewing apparatus and more particularly to an apparatus for guid ing, positioning and sewing workpieces such as pocket blanks used in pants.

In the production of garments, such as pants, almost endlessly repetitive sewing operations are required for a competitive manufacture of these garments. Thus, for example, in the manufacture of pants, the back pockets of pants are fashioned from a pocket blank which undergoes a number of manufacturing steps until it is incorporated into the finished pants article. One of the' steps in the manufacturing process is to sew the pocket blanks on three sides. For example, as illustrated in the above-identified patent, there is a need for an apparatus which will sew along one side of a workpiece, then turn the workpiece to sew along a second side and finally turn the workpiece through a third angle to sew the third side.

In accordance with the present invention, an automatic sewing apparatus is provided which is sequentially controlled to position and sew fabric workpieces. In an embodiment of the present invention, a combination of rigid and movable guide means cooperate with the sewing machine drive means, sewing machine feed means, presser foot, feed dog and needle to provide a unique sequencing device for performing sewing operations requiring a plurality of turns.

In the Drawings:

FIG. 1 is an isometric view of a complete pocket blank sewing machine;

FIG. 2 is a top view of the sewing table and an embodiment of the present invention;

FIG. 3 is a section view taken along line 3--3 of FIG.

FIG. 4 is a section view taken along line 44 of FIG.

FIG. 5 is a side section view taken along line 55 of FIG. 2; and 1 FIG. 6 is a schematic circuit diagram illustrating the manner in which FIG. 6A through 61 should be arranged to form a complete circuit diagram; and

FIGS. 6A through 61 together comprise a circuit diagram illustrating the operation of the machine shown in FIG. 1.

Referring first to FIG. 1, a sewing machine apparatus is shown which supplies workpieces along a conveyor 57a to a sewing machine 11 for sewing. After the workpiece is sewn, it is removed from the sewing area by conveyor 57b. Conveyors 57a and 57b are formed by continuously rotating sprocket and chain interlinked conveyor rollers 10. Conveyor 57a is slightly angled to the sewing area to permit a corner of the curved edge of the workpiece, which in this case is a pocket blank 2, to be properly positioned under the sewing machine. While traveling on conveyors 57a, the pocket blank 2 is urged against a guide rail 13 which properly positions the pocket blank for arrival at the sewing area. The principal advantage of guide rail 13 is that the pocket blanks do not have to be placed on conveyor 57a in any precise manner. A workpiece may also be fed into the sewing machine by other means such as by different conveyor feed arrangements or by hand.

For convenient handling, as well as for achieving a proper timing sequence, the speed of the input conveyor 57a may be selected so that each pocket blank will arrive at the sewing areajust after sewing the previous pocket blank has been completed. In addition to selecting the speed of the conveyor, which is accomplished by adjusting the rate at which the rollers 10 turn, the length of the conveyor may also be selected to provide for the optimum operating conditions.

Any conventional sewing machine, such as Singer Model 281, which walks the fabric through the machine to generate a stitch pattern by the use of feed dogs, can be used. A few modifications, however, must be made to the machine as will become apparent later.

Referring now to FIGS. 2, 3, 4 and 5, the incoming pocket blank 2, after leaving the side guide rail 13, proceeds onto a sewing table 15 which is a highly polished metal plate with downcurving edges. Table 15 has a stationary side guide 14 oriented vertically at the back edge of table 15. Side guide 14 is placed at a slight angle from that defined by the normal feed direction of the sewing machine and urges the fabric workpiece away from the straight line and away from the sewing machine head 111 so that the stitch pattern is kept at a uniform distance from the edge of the blank.

Preceding side guide 14 is a catch hood 52 which is curved upwardly towards the rollers 10 from which it receives the incoming blank. Hood 52 is in the form of a segment from a bent disc with the edge facing away from rollers 10 tapering downwardly towards the sewing machine needle. The function of the hood 52 is to prevent the upturning of corners of a blank when it is received on sewing table 15 and when it is turned through during the sewing operation.

It was found in practice that the location of the sewing machine feed dog 112 adjacent to the output side of guide 14 caused a guiding action that held the pocket blank against the output side 141 of the guide 14 more than against the input side of this guide. Therefore, drag was introduced on the limp fabric blank 2 on the input side of the guide to achieve the proper feeding action. This drag was formed by placing a drag wheel near the following edge of hood 52, as shown in FIGS. 2 and 5, to engage the blank after it emerges from under the hood.

The drag wheel 115 is illustrated in the assembly in FIG. 2 and in cross-section in FIG. 3. The support axis- 115a upon which wheel 115 rotates is pivoted on a support 11511 to disengage wheel 115 from a blank. Support 115!) is located beyond the side guide 14. A fulcrum arm 115C projects below the supporting axis 115a so that when a rod from a pneumatic cylinder 115d is extended, the restoring force of a spring l15e is over come and axis 115a rotates wheel 115 upwardly about support 1151). The spring l15e is adjusted, by appropriate means such as a screw or an I-bolt attached to the upper arm ll5fof the housing, for proper tensioning and variation of the drag effect created by wheel 115. The activating means for wheel 115 will be explained further in the description pertaining to the electrical circuits. For an understanding of the mechanical operation, however, it is sufficient to note that the drag wheel 115 is lifted when the sewing machine presser foot 113 is lifted for pivoting the blank about the sewing machine needle 21. Drag wheel 115 can be a narrow roller, wheel, or friction type device, so that adjusting its drag angle with respect to the direction of the pocket travel will optimize the guiding characteristics. In addition to preventing the feed dogs 112 from moving the pocket away from guide 14, drag wheel 14 also coacts with the feed dogs 112, to urge the pocket blank against the side guide 14 which, as previously noted, is at a slight angle to the normal sewing machine feed line.

Pocket blank 2 needs to be carefully guided for the first few stitches because of the curvature of the blank 2 in its freelaying condition. To aid in such guiding, a side guide idler wheel 16 is provided which is lowered and traps blank 2 just as the sewing machine presser foot 113 comes down. The axis of idler wheel 16 is askewed to the axis of rotation of the next to last roller b. Wheel 16 is part of an arrangement consisting ofa wheel lever 16a which is held in a wheel idle position, as shown in solid lines in FIG. 4, by the rod of a spring loaded cylinder 53. Lever 16a is pivoted at a fulcrum point 54 and causes the wheel 16 to engage an incoming blank when the rod of air cylinder 53 retracts. After the first few stitches, the air supply to cylinder 53 is cut off and wheel 16 returns to its up or idle position.

The actual sewing is carried out by lowering the presser foot 113 on the incoming blank 2 and effecting the continuous guiding of the pocket blank 2 by the cooperation of feed dogs 1 12, drag wheel 1 15, and the side guide 14.

After the guiding means and feed dog 112 which were discussed previously, have fed the pocket blank to near the end of the first line of stitches, a photocell l9 detects the end of the blank and activates appropriate means to shift the sewing machine 11 to an inching speed. For example, the motor speed is dropped from 3,450 rpm to about 400 rpm. Sewing machine slowdown is accomplished by a clutch which disengages the sewing machine motor connected to the conventional sewing machine drive means and engages a brake wheel which is a geat wheel driven by a small motor rotating at about 400 rpm. This slowdown device is readily available on the market such as from American Safety Table Company.

The purpose of the inching speed is to prepare the machine for accurate stopping with the needle 21 in the down position. Thus, when the inching motor is running at 400 rpm, a needle positioning device (not shown) is activated which senses the correct needle position and, slows down the sewing machine by applying dynamic breaking of the inching motor. This needle positioning device is also known in the art and is available from American Safety Table Company.

A photocell 20 detects the end ofa pocket blank and activates the above-mentioned slowdown device for positioning the needle 21 in a down position at a point equidistant from the two edges of the blank. Proper ad justment of photocells l9 and 20 ensures that the needle will stop at this desired point. In operating the sewing machine, the presser foot 113 is lifted by a pneumatically activated piston rod 116 acting on a lever 113b. The force of piston rod 116 overcomes a spring (not shown) which holds the presser foot 113 in its down position. A hand operated presser foot lifting latch 113e, shown in FIG. 1, is also provided which lifts and holds the end of lever 113b in an up position. This presser foot lift means is also well known in the art. A switch 113d is placed beneath the lever 113b which senses the up position of the presser foot as well as the presser foot down position. The operation of this switch in conjunction with the machine control will be explained further in connection with the circuit diagram.

As pneumatic cylinder 116 lifts presser foot 113, the air cylinder 115d, shown in FIG. 3, lifts the drag wheel 1 15 from the table. The needle 12, in its down position, is now used as a pivoting point for the workpiece. A pneumatically activated pocket turner rod 22 extends and pushes the pocket blank 2 about the needle thereby pivoting the blank for any desired angle, such as A plastic block 221 is provided at the rod end and is appropriately shaped and angled to slide on the polished table 15. An elongated lip 222 extends from the top part of block 221 and holds the blank from vertical movement. The length of the cylinder rod stroke can be adjusted for any appropriate turning angle but in this case is adjusted for a 90 turn. As the pocket turner rod 22 retracts, the presser foot 113 and drag roller 115 go down. Sewing, guiding and turning between the two remaining sides is now accomplished in the same manner as explained above.

As the pocket blank is sewn along the last side, the sewing operation control means instead of signaling another turn continues beyond the end of the pocket and the first edge of the incoming pocket is sewn in a continuous motion.

As the outgoing blank leaves the table 15 after the sewing operation, the geometry of the particular blanks may be such that the incoming blank strikes a trailing corner of the preceding blank. To eliminate such striking, which may mis-position the incoming blank, a pocket corner lifter rod 23 is provided which is activated by photocell 19 when it senses the incoming blank. This lifter rod 23 is activated by a pneumatic cylinder 231 through a solenoid valve appropriately interconnected to the electrical control circuit. The lifter rod 23 is retracted immediately when a proper program signal is received, i.e., when the new blank is trapped for sewing by the sewing machine presser foot 1 13.

ELECTRICAL CONTROL SYSTEM I. Sewing the First Edge As the pocket blank travels along on the conveyor rollers 10, its leading edge comes into the path of the light beam shining from lamp 19a, shown in FIG. 6A, to the photocell 19. Photocell 19 is connected in a circuit 560 in combination with

transistors

561, 563, 593 and 595- The result is that the covering of the photocell l9 creates an output signal on lead 577 which is connected to the coil 564 of an INCH relay 562. This energizes relay 562 and moves contact arm for contacts 572 to its lower position in which it connects the coil 584, of another relay 582, to ground. The other terminal of coil 584 is connected to the common positive 26 volts DC supply through the contact 580 which is part of a SEW relay 576 which is, at this time, de-energized. Thus, relay 582 is energized and relay contacts 588 are actuated to energize a corner lifter valve 590. Actuation of the comer lifter valve 590 actuates a pneumatic corner lifter cylinder 23 which lifts the left hand trailing edge of the pocket blank which was previously sewn thus preventing interference with the new pocket blank which is being sewn.

The new pocket continues to move and covers the optical path between the light source 2012 (see FIG. 5) and the sew photocell 20. Photocell is connected into a photocell amplifier circuit 592 (see FIG. 6C). When the last transistor 593a turns on, output lead 594 is grounded, thus energizing the coil 598 of a second sew" relay 596 (see FIG. D). This actuates contacts 608 (see FIG. 6G) and has the effect of energizing the coil 612 of another relay 610 (see FIG. 6B). Referring next to FIG. 6H, the foregoing has the effect of connecting the coil 612 to the power supply through contacts 575 of the relay S62 and contacts 567 of another relay 568 (see FIG. 6E). The energization of relay 596 also causes the presser foot and guider to drop down onto the pocket. The dropping of the presser foot actuates a microswitch 614 (see FIG. 6G) to move its arm to the rightmost position to connect one terminal of a clutch valve 615 (see FIG. 6H) and the coil 612 of relay 610 (see FIG. 6E) to ground. This actuates the clutch and starts the sewing machine.

The second sew relay 576 (see FIG. 6E) is energized at the same time the first sew" relay 596 (see FIG. 6D) is energized because the coil 578 of relay 576 is connected to the same energization lead 594 as is the coil 598 of relay 5 96. INCH" relay 562 is energized a short time prior to the energization of the SEW relays. When the energization of relay 576 causes the switching of contacts 581, this connects a charged capacitor 639 (see FIG. 6D) through relay contacts 574 to the coil 636 of a relay 634 (see FIG. 6F). Contacts 638 of relay 634 (see FIG. 61) are momentarily actuated to de-energize a side guider valve 640 which briefly brings the side guider down upon the pocket momentarily to aid in guiding its movement.

Considering once againthe movement of the pocket blank during the stitching of its first side, as the pocket blank moves far enough to uncover the photocell 19 so that light reaches it from lamp 19a (see FIG. 5) the resistance of the photocell 19 drops to a low value, transistor 56] turns on,

transistors

563 and 593 turn off, and transistor 597 also turns off after a time delay sufficient to allow the capacitor 583 to discharge to a value lower than the Zener breakdown voltage of a Zener diode 579 connected in series with the base lead of transistor 697. The time delay for transistor 597 to be turned off can be adjusted by means of potentiometer 584 which is connected in parallel with capacitor 583.

At this time, the first seam of the pocket has been sewn to within approximately one-half inch of the pocket bottom, when transistor 597 turns off, relay 562 (see FIG. 6D) is de-energized. This causes a shift in the sewing speed of the sewing machine to a slow speed so that the pocket blank can be stopped accurately to make the turn to sew the next seam.- De-energizing relay 562 de-energizes the clutch valve 615 and there fore de-energizes the clutch. This also energizes the brake valve 569 (see FIG. 6H) and transistor 595 through contacts 575 of relay 562 (see FIG. 6G) and contacts 567 of relay 568 (see FIG. 6H). This new connection rapidly slows down the sewing machine. The deenergization of relay 562 energizes the coil 652 of relay 650 (see FIG. 6F). The energization of relay 650 (see FIG. 6F) closes contacts 654 and energizes the coil 624 of another relay 622 (see FIG. 6F) which closes contacts 627 (see FIG. 61) which in turn energize a small auxiliary sewing machine motor 629 (see FIG. 6I) which drives the sewing machine at a slow speed. Motor 629 preferably is a series-wound DC motor which produces a low speed which is termed an inching speed herein.

After the sewing machine makes two or three revolutions at inching speed, the pocket has moved far enough to uncover the photocell. 20 and de-energize the two sew relays 596 and 576. When relay 596 is deenergized, a synchronizer cam 656 (see FIG. 6D) controls relay 650. The synchronizer cam 656 is attached to the main shaft of the sewing machine and has two

brush contacts

657 and 658, as shown in FIG. 6D). The cam 656 has a cut-out portion of a lesser radius than the remainder of the wheel. The wheel is made of a conductive material. When the sewing machine rotates to positions such that contact 657 is in the gap, the needle is down, relay 650 is de-energized, and the auxiliary motor 629 and the sewing machine stop. Note, that when contacts 655 (see FIG. 61) of relay 650 are actuated, they place a short circuit across the armature of motor 629 while a field winding of the motor still is being energized. This provides dynamic braking of the motor and stops it very rapidly. Relay 622 remains energized for a short time after relay 650 is de-energized because of the charge stored on capacitor 631 (see FIG. 6F).

After a short time relay 622 de-energizes and switches contacts 626, thus causing presser and guider valve 620 (see FIG. 6I)-to operate to lift the presser foot and guider. The lifting of the presser foot causes the microswitch 614 (see FIG. 6G) to move to its leftmost position. This grounds the coil to 662 of a TUR- NER" relay 660, and permits a charged capacitor 664 (see FIG. 6E) to discharge through coil 662 and actuate the relay 660. Contacts 666 (see FIG. 6G) of relay 660 are switched to ground one terminal of the solenoid of a TURNER VALVE 668 which actuates the pocket turner cylinder which rotates the pocket and prepares it for the sewing of the next seam.

During the rotation of the pocket, the coil 672 of a relay 670 (see FIG. 6D) is energized through the con tacts 674 of relay 660, and the relay 670 is latched in an energized condition by one of its own sets of contacts 676. The turning pocket covers first the sew photocell 20, thus again actuating relays 596 and 576, and then the pocket covers the inch photocell 19, thus energizing relay 562. This action de-energizes the presser and guider valve 620 (see FIG. '6I), allowing the presser foot to drop and move microswitch 614 (see FIG. 6G) to the left position. This energizes the clutch valve 615 (see FIG. 6H) to start the sewing machine in sewing the second pocket. I

II. Sewing the Second and Third Edges The operation of the machine in sewing the second seam and negotiating the second turn is substantially the same as with the first seam and first turn, with several exceptions which are discussed as follows. First, the contacts 673 of relay 670 connect inching time control potentiometer 582 in the inching circuit 560 in place of potentiometer 584 in order to permit optimizing the timing of the circuit functions. Also, when relay 660 is actuated at the second turn, its contacts 663 connect the coil 680 of a SEW OFF relay 678 (see FIG. 6D) to a capacitor 677 through contacts 679 of relay 670. The capacitor 677 has a charge which was stored during the turning of the pocket at the first corner. This charge is discharged through coil 680 to operate relay 678, and the contacts 682 latch the relay 668 in an energized condition.

The operation of relay 678 performs several functions; the switching of contacts 681 prevents the turner cylinder from turning the pocket at the end of the third seam, and energizes coil 630 of relay 628 (see FIG. 6F), whose contacts 691 ground the capacitor 664 through contacts 613 of relay 610 (see FIG. 6E) and discharge it, thus preventing the operation of the turner relay 660 the next time the presser foot microswitch 614 is operated. Also, a new time delay potentiometer 686 (see FIG. 6D) is connected in series with the usual time delay potentiometer by means of contacts 685. This permits a longer time delay at the end of the third seam in order to permit the sewing of a thread chain" between adjacent pockets. Further, the pocket pickup and transfer unit traverses another cycle when contacts 683 of relay 678 connect to operate pocket feeding apparatus.

Hence, a situation exists in which the old pocket still is covering the sew photocell 20, and the new pocket has just covered the inch photocell 19. The inch timing circuit is in the middle of its timing function and the new pocket covering the inch photocell would reset this timing circuit and the machine would continue to sew instead of sewing a thread chain of approximately one-halfinch and then stopping. An inhibit circuit is employed to prevent the undersired action. When relay 668 energized, its contacts 681 energized relay 628 (see FIG. 6F) and supply a base drive to turn on transistor 574 (see FIG. 6A). Note that the collector circuit of transistor 574 is connected to the inch photocell 19. The pocket was at the start of the second turn when relay 678 energized. Capacitor 690 (see FIG. 6A) charges slowly enough not to reach the breakdown voltage of Zener diode 692 before the pocket, in turning, covers the inch photocell 19 which turns off transistor 561 and turns on

transistors

563, 593, 595 and 573, keeps transistor 574 from turning on due to loss of its base drive. As the pocket is being sewn from the second turn and uncovers the inch photocell 19, transistor 561 turns on, and

transistors

563, 593, 595, and 573 turn off, which now permits base drive and turns transistor 574 on. Since transistor 574 is shunted across the inch photocell, the circuit will be locked in this mode of operation and a new pocket covering the inch photocell has no effect as the circuit continues to function as if the inch photocell were not being covered until the sewing machine has formed the chain thread, and relay 678 has been reset by the opening of contacts 580 of relay 576 (see FIG. 6B). This causes relay 628 (see FIG. 6F) to de-energize after a short delay due to capacitor 693. The de-energization of relay 628 turns off transistor 574 and returns the inch circuit 560 back to its normal operation.

Iclaim:

1. An apparatus for guiding and sewing a workpiece comprising: a smooth surface; a sewing maching over said surface for sewing including a needle, and a presser foot and feed dogs for advancing a workpiece; a first guide means adjacent said sewing machine for edge guiding said workpiece; a second guide means adjacent said first guide means for applying a retarding force on said workpiece; a third guide means for initial engaging of said workpiece against said first guide means; means for lifting a portion of a workpiece during sewing; means for disengaging said second guide means and said presser foot from said workpiece; and means for changing a sewing direction on said workpiece operatively interconnected to said means for disengaging.

2. An apparatus as described in claim 1 wherein said first guide means comprises a curved hood spaced from said smooth surface.

3. An apparatus as described in claim 1 wherein said second guide means comprises drag means for providing a resistance to a movement of a workpiece away from a line of sewing.

4. An apparatus as described in claim 1 and wherein, said drag means is a drag wheel rotatable at an angle convergingly to a line of sewing.

5. An apparatus as described in claim 1 including, input means for supplying said workpiece to said smooth surface, and wherein said third guide means is a wheel with its principal axis askew to a line of sewing engagable with said workpiece against said input means during an initial engaging of said workpiece.

6. An apparatus as described in claim 1 and wherein, said means for changing a sewing direction includes, means for detecting an end of said workpiece operatively interconnected to said disengaging means, and a telescoping arm operatively interconnected to said detecting means an end of which is in contact with said smooth surface for turning said workpiece about said needle.

7. An apparatus as described in claim 1 and wherein, said means for changing a sewing direction includes, means for detecting an end of said workpiece, a telescoping arm operatively interconnected to said detecting means which is in contact with said smooth surface for turning said workpiece about said needle for sewing said workpiece in another direction.

8. An apparatus as described in claim 2 including a guide rail having a vertically extending wall located upstream of said first guide means in the direction of travel of a workpiece, for guiding said workpiece into said first guide means.

9. An electrical circuit, for a guiding and sewing apparatus including a workpiece corner lifter, a sewing machine having a needle and a presser foot, a drag guider, an initial guider and a workpiece turning device, comprising:

a. first detection means for detecting the presence of a workpiece in a sewing area;

b. means connected to said first detection means for activating the workpiece corner lifter;

0. second detection means for detecting a predetermined sewing position of the workpiece. in reference to said sewing machine needle;

d. means connected to said second detection means for lowering a sewing machine presser foot and a drag guider onto the workpiece when the workpiece is in a predetermined sewing position;

e. means operatively interconnected to the presser foot for activating the sewing machine when the presser foot is lowered;

f. means connected to the sewing machine activating means for activating an initial guider during initial sewing operation of the sewing machine on said workpiece;

g. means connected to said first detection means for slowing the speed of said sewing machine when the workpiece is not detected by said first detection means;

h. means connected to said second detection means for stopping the sewing machine in a needle-down position when the workpiece is not detected by said second detection means;

i. means connected to said stopping means for raising the presser foot and said drag guider when the sewing machine is stopped by said stopping means;

j. means operatively interconnected to said raising means for activating a turning device to reposition a workpiece in a predetermined sewing position detectable by said second detection means when the presser foot and drag guider are operatively activated by said means for raising said presser foot and said drag guider; and

k. means for preventing the activation of said slowing, stopping and turning means upon sewing a last stitch'line on the workpiece.

10. A circuit as described in claim 9 and wherein, said first and second detection means each include, a photoelectric cell, and amplifying; means connected to said cell for increasing an output voltage of said cell.

11. A circuit as described in claim 9 and wherein, said circuit comprises a power source, and said workpiece comer lifter activating means, said presser foot and drag guider raising and lowering means, said initial guider activating means, said stopping means and said turning device activating means each comprise at least one relay for providing connection to said power source.

12. A circuit as described in claim 9 and wherein, said means for activating the sewing machine comprises, a primary sewing machine motor, a clutch for engaging said primary motor, and a switch operable by the presser foot for activating said clutch.

13. A circuit as described in claim 12 and wherein, said slowing means comprises, means operatively connected to said first detection, means for disengaging said clutch, means for braking the sewing machine, and an auxiliary motor engagable with the sewing machine for driving the sewing machine.

Claims

9. An electrical circuit, for a guiding and sewing apparatus including a workpiece corner lifter, a sewing machine having a needle and a presser foot, a drag guider, an initial guider and a workpiece turning device, comprising: a. first detection means for detecting the presence of a workpiece in a sewing area; b. means connected to said first detection means For activating the workpiece corner lifter; c. second detection means for detecting a predetermined sewing position of the workpiece in reference to said sewing machine needle; d. means connected to said second detection means for lowering a sewing machine presser foot and a drag guider onto the workpiece when the workpiece is in a predetermined sewing position; e. means operatively interconnected to the presser foot for activating the sewing machine when the presser foot is lowered; f. means connected to the sewing machine activating means for activating an initial guider during initial sewing operation of the sewing machine on said workpiece; g. means connected to said first detection means for slowing the speed of said sewing machine when the workpiece is not detected by said first detection means; h. means connected to said second detection means for stopping the sewing machine in a needle-down position when the workpiece is not detected by said second detection means; i. means connected to said stopping means for raising the presser foot and said drag guider when the sewing machine is stopped by said stopping means; j. means operatively interconnected to said raising means for activating a turning device to reposition a workpiece in a predetermined sewing position detectable by said second detection means when the presser foot and drag guider are operatively activated by said means for raising said presser foot and said drag guider; and k. means for preventing the activation of said slowing, stopping and turning means upon sewing a last stitch line on the workpiece.

10. A circuit as described in claim 9 and wherein, said first and second detection means each include, a photoelectric cell, and amplifying means connected to said cell for increasing an output voltage of said cell.

11. A circuit as described in claim 9 and wherein, said circuit comprises a power source, and said workpiece corner lifter activating means, said presser foot and drag guider raising and lowering means, said initial guider activating means, said stopping means and said turning device activating means each comprise at least one relay for providing connection to said power source.