JPS5850987A - Method and apparatus for preventing loosening of stitch terminal of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and a device for mechanically and automatically entangling a knot at the thread end at the end of sewing in a scoop-stitch sewing machine to prevent the sewing from unraveling. The purpose of this is to automatically and mechanically intertwine the thread ends so that they do not slip out of the knot at the end of sewing on a scoop-stitch sewing machine, and create a seam that will not come undone. It is an object of the present invention to provide a manufacturing method and device for preventing unraveling.

As shown in FIG. 10, the push-up plate 30 in the conventional scoop-stitch sewing machine uses the push-up crank 34 to push up the rotation of the upper shaft 31 through the push-up eccentric 32 and push-up rod 33 as the sewing machine rotates. 35, and the reciprocating rotational movement is made into a reciprocating rotational movement centered on the thrusting crankshaft 36, and the reciprocating rotational movement is caused to move back and forth as shown in FIG. This is a swinging motion in the direction, and pushes the fabric 40 upward as shown in FIG. On the other hand, as shown in FIG. 11, the dough presser 41 has a presser shaft link 45 and a presser shaft arm 46 at the tip of a knee lever shaft arm 44 fixed to a knee lever shaft 43 that interlocks with a knee lever 42.
, is installed via the presser foot 4IllI47, and the knee lever 42
By pushing K in the direction of arrow 48, the knee lever shaft 43, presser foot shaft link 45, and presser foot shaft 47 move in the direction of the arrow in FIG. It is. If the large gear 5-side meshes with the small gear 5'1 fixed to the thrust crankshaft 36 in the U-shaped groove 50 on the lower side surface of the presser shaft link 45, it can move freely in the direction. When the rollers 53 are fitted and the knee <-42 is pushed in the direction of the arrow 48, the dough presser 41 is lowered and at the same time the large gear 52 rotates in the direction of the arrow 54, and the small gear 51 is rotated accordingly. The fixed thrusting crankshaft 36 also rotates in the direction of arrow 55, and the thrusting plate 30 also retreats as shown by the broken line in FIG. 5 via the crank eccentric 35.

However, as shown in FIG. 12, the end portion 40& of the fabric 40 folded in half and the portion 4G that contacts the core portion 40& due to folding.
b is scooped up by the curved needle 56 that moves in an arc, and when the knee lever 42 is activated at the end of embroidery, both the push-up plate 3'0 and the fabric presser foot 41 move to the knee lever 4.
2, so they move backward and downward respectively, so no special operations can be performed on the final stitch, and the stitches and stitches are similar to a series of scoop stitches, so the hem of a skirt or pants can be sewn as shown in Figure 18. When performing blind stitching work such as sewing, it may not be possible to form a perfect knot at the end of the sewing process, and the final stitch may fail during the subsequent sewing process, during wearing, washing, etc. It is easy to pull out the stitches, and once the end of the thread starts to pull out, the #1 stitches may suddenly come apart in a chain, creating a situation where it is impossible to control the stitches.

However, in the present invention, the push-up plate and the material presser are individually raised and lowered by solenoids, and when the scoop stitch sewing is completed, the sewing machine is rotated two more times by depressing the pedal again, and a loop is made from the first rotation and the next one is made. I made a stone scoop stitch that went through the loop from the center in one rotation, and the result was a knot that I was not used to, so I was able to say that I had completed a stable scoop stitch for the first time. It is. I will now explain in detail the attached drawing which shows an example of the application of the present invention.L is a straight presser foot shaft link without the U-shaped groove 6G on either side as in the past, and it is different from the conventional scoop stitch sewing machine. Similarly, its distal end is pivotally supported on a presser shaft arm 46, and its base end is pivotally supported on a group lever shaft arm 44. 2
is a solenoid for lowering the fabric presser that is attached to the bottom of the sewing machine bow/I/a with a wood screw or the like. 4 is a connecting chain connecting the solenoid 2 and the tip of the knee lever shaft arm 44;
The device is such that when the solenoid 2 is turned on, the dough presser 41 is lowered. Reference numeral 5 denotes a push-up par, which is rotatably supported in place of 58 on the side of a large gear 52 that meshes with a small gear 61 fixed to a push-up crankshaft 86 of a conventional scoop stitch sewing machine. 6 is a solenoid for retracting the push-up plate attached to the lower part of the vfJ with sewing machine tape, similar to the solenoid 2 above. Reference numeral 7 denotes a connecting chain that connects the solenoid 6 and the tip of the thrust bar 5. When the solenoid 6 is turned on, the plate 80 is raised via the large gear 62 and small gear 51 as shown in FIG. It is like retreating. Reference numeral 8 denotes a sewing machine molymer using a known electromagnetic induction motor with a built-in brake and clutch, which rotates the upper shaft 81 of the sewing machine via a pulley, a belt, etc. Reference numeral 9 denotes a known position detector which is installed by extending the upper shaft 81 outward; for example, a rotor attached to the extension of the upper shaft 81 rotates between a magnet and a Hall element, thereby detecting the needle positioning detector 1G and rotational speed. It constitutes the container 11. 12 is a rotary solenoid for thread cutting that constitutes an automatic thread cutting device;
The thread is cut by a rotating thread cutter 12' attached to the tip of the arm. 1B is one that enables the three operations of the conventional turning back 17. 19 is a stop signal detector installed in the control box 18 connected to the Veda/L'14, and indicates that the Veda/L'14 is in neutral operation 16 (either separated from the Veda/1/1'4 or lightly placed on it). status (fund)
It is used to detect the presence of 20 is also Veda/
This is a speed control detector that detects the 1/14-stroke operation 16, and controls the rotational speed of the electromagnetic induction motor 8 according to the strength of the depression operation 16. 21 is a pedal depression detector which similarly detects the pedal depression motion 17 of Beda/l/14. Reference numeral 22 denotes a microphone computer having a system configuration as shown in FIG. 6, which is installed in the control box 18, where OPU is a central processing unit, ROM is a read-only memory, and RAM is a random access memory. 23 is an input interface circuit, which includes a needle positioning detector 101, a rotation speed detector 11, and
Each operation of the knee switch 13 and pedal 14 15.16°1
Detectors 19, 20, and 21 corresponding to 7 are connected, and signals from each detector and switches 10, 11, 13, 19, and 20, 21 are input to a microcomputer 22. Reference numeral 24 designates an output interface circuit, which includes a solenoid drive circuit 25 for the fabric presser lowering solenoid 2, a solenoid drive circuit 26 for the uplift plate retraction solenoid 6, and a same drive circuit for the thread cutting rotary solenoid 12. 27, the electromagnetic brake circuit 28 for stopping the motor of the sewing machine motor 8, and the electromagnetic clutch circuit 29 for transmitting motor power, due to a connection problem, the microcomputer 22
When the signals of the respective detectors and switches 10, 11, 13, 19, 20, 21 are input according to the memory written in the ROM of the respective circuits 25, 26, 27, 28
It outputs the following signals to ゜29.

When the pedal 14 is depressed to the operation 16 during scoop stitch sewing, the electromagnetic clutch circuit 29 is turned on and the sewing machine motor 8 rotates. Scooping stitch sewing When the pedal 14 is set to neutral operation 15 at the end of sewing, the electromagnetic brake circuit 28
is turned on, the sewing machine motor 8 stops when the bent needle 56 reaches the top dead center according to the needle positioning detector 10.

Next, when the pedal 14 is depressed again and the operation 17 is performed, the solenoid 6 for retracting the thrust plate is turned ON by two rotations of -8 of the sewing machine motor 8, and the sewing machine motor 8 rotates twice. When the sewing machine stops, the timer works and the sewing machine continues sewing for a certain period of time←−
→ After that, the rotary solenoid 12 for thread cutting is turned ON 1 ← Zero thread → The thread cutter 12' cuts the thread, and the solenoid 2 for lowering the fabric presser is turned on for the thread cutting and cutting time from the stop of the sewing machine. Turn ON and lower the dough presser foot 41.

,o-! By pressing the knee switch 13, the solenoid 6 for retracting the push-up plate and the solenoid 2 for lowering the dough presser are activated.
Both are turned on, and the push-up plate 30 and dough presser foot 4 are turned on.
1 retreats or descends.

Since the present invention has the above-mentioned configuration, when starting the work, the operator presses the known knee switch 13 and at the same time causes the push-up plate 30 to retreat by the action of the solenoid 26, and at the same time presses the dough presser. 41 is similarly lowered to create a gap between the push-up plate 30 and the fabric presser foot 41 with respect to the stationary needle plate 49, and the fabric 4o to be scooped is easily inserted into the gap. be equipped to do so. When the fabric 40 is inserted, the drawer switch 13 is released and the push-up plate 30 and fabric presser 41 are raised. Next, when the pedal 14 is depressed, the electromagnetic clutch circuit 29 built into the sewing machine motor 8 is turned on, and the sewing machine starts rotating. In this way, if the pedal is kept depressed from the beginning of sewing to the end of sewing, the hem hem hem stitching process of one piece of target fabric 40 is completed and the sewing is finished. If it is necessary to interrupt the sewing work midway through, the sewing machine can be stopped by shifting the pedal to neutral. However, in this case, both the push-up plate 30 and the dough presser foot 41 remain raised. Thus, the pedal is equipped to automatically return to the neutral position and maintain that state when the foot is removed from the pedal or when the foot is placed lightly on the pedal. When the sewing operation reaches the sewing end position, depress the pedal again. In the olden days, the microcomputer 2 was used one after another to trigger the thread trimming operation by stepping back on the pedal.
2, it can be activated automatically. When the user depresses the pedal in this manner, the sewing machine is connected to the motor 8 and stops at a predetermined position, that is, top dead center. When the rotation of the sewing machine is thus stopped, the uplift plate retreating inlet 6 is energized, and only the uplift plate 30 is lowered independently. The sewing machine, which had stopped in this state, rotates once. However, since the push-up plate 30 is lowered, the fabric is not pushed up into a mountain shape, and even if the curved needle 56 swings, the fabric does not reach it during its stroke. There is no penetration, so there is no stitching, and a ring is created from just one eye on the shield. When the sewing machine rotates once, the current to the solenoid 6 for retracting the uplifting plate is cut off, and the uplifting plate 30 is raised by the force of the spring installed in the uplifting device of the sewing machine, returning to its normal state. Revenge. As the push-up plate 30 rises, the sewing machine rotates one more revolution.

Then, only one normal seam appears in the bush. needle 5 on it
6 stops at the original top dead center. In this case, the sewing machine rotates twice in succession, one for empty stitching and one for lock stitching.

When the rotation of the sewing machine stops in this way, a timer is activated and after a certain period of time has elapsed (in order to ensure that the sewing machine does not cut the thread after it has stopped), the thread cutting section rotary solenoid 12 is energized, and the thread cutting cutter 12' is activated to cut the thread. Cut. In this way, the operator presses the knee switch 13 after seeing that the thread trimming is completely completed, and as a result, the push-up plate 30 retreats, the material presser foot 41 also descends, and at the same time leaves the throat plate 49.

Therefore, a gap is created between the two, so the fabric 4 that has been sewn
0 from the sewing machine and the operation is completed. Further, seam tightening to prevent the seam from coming undone at the final point of sewing will be explained in detail in the order shown in FIGS. 9A, B, O, and D.

First, Fig. 14 is an explanatory diagram showing the end of sewing in a conventional wire sewing machine.At the end of sewing with a conventional wire sewing machine, the thread is cut at part a by scissors or an automatic thread cutter. Therefore, when the thread end a comes out from the blind stitched part as shown by the temporary line, it is extremely easy to unravel (because the stitch structure of this scoop stitch sewing machine is a single ring stitch) and the temporary line There is a serious danger that if the core of the thread is pulled in this state, the stitches will come undone one after another and disappear.This is the origin of the invention. Next, Figure 9 A and B.

0 is an explanatory diagram of the sewing end according to the present invention, and in FIG. 9, the α section is the part where a normal scoop stitch appears when the pedal is depressed. Point 2 is the point where the pedal is pressed back, the push-up plate 30 is moved back, and one stitch is sewn without penetrating the fabric 40, and one loop 0 is produced from point r. In the δ portion of FIG. 9B, when the push-up plate 30 is raised and the curved needle 56 enters for the second scooping operation, the sewing thread d of this time is inserted into the loop O from the previous time using the curved needle. 56. Further, FIG. 9B shows the thread cutting, and the thread is cut at the zero point. In the same case C, when the thread end d is further pulled in the direction of the arrow in the intermediate state where the knot is about to be formed, the loop 0 becomes smaller and smaller. The thread end d passes through the fabric 40 to complete the final blind stitch. g is an arrow indicating the return stroke of the needle, and h is an arrow indicating the direction of movement of the fabric. In the ninth drawing, when the thread end d is cut at the zero point, the other cut end 1 of the thread moves back together in the direction of the arrow g while being held by the curved needle 56, and is replaced with the next material. When performing a scoop stitch operation,
It is ready to be sewn as is.

[Brief explanation of the drawing]

The attached drawings show an example of carrying out the present invention, and FIG. 1 is a front view of the scoop stitch sewing machine of the present invention, FIG. 2 is a left side view of the same, and FIG.
The figure is a perspective view of the main part of the push-up plate and the retraction device, Figure 4 is a perspective view of the main part showing details of the attachment of the push-up bar and the large gear, and Figure 5 is the push-up of the push-up plate. Figure 6 is a side view of the main parts of the retracting mechanism, Figure 6 is a perspective view of the main parts of the lifting device for the fabric presser, Figure 7 is a block diagram of the control circuit using a microcomputer, and Figure 8 is a diagram of the operation of each part at the end of sewing. The time chart shown in FIG. 9 is an explanatory diagram showing the order of construction of the final knot.
Figures 10 to 14 show conventional wiring sewing machines.
Figure 10 is a perspective view of the main parts of the push-up and retraction device for the push-up plate;
Figure 11 is a perspective view of the main parts of the lifting device for the dough presser;
13 is a side view of the same, and FIG. 14 is an explanatory view of the final stitch by the conventional wire sewing machine y. L... Straight presser foot shaft link, 2 Solenoid for lowering the fabric presser, 3... Sewing machine table, 4... Connecting chain, 5...
... Thrust bar, 6... Solenoid for retracting the thrust plate,
7... Connecting chain, 8... Sewing machine motor, 9... Position detector, 10... Needle positioning detector, 11...
Rotational speed detector, 12... Rotary solenoid for thread cutting, 12'... Thread trimming cutter, 13... Knee switch, 14... Pedal, 15... Neutral operation, 16.
... Depressing motion, 17... Depressing back motion, 18...
・Control box, 19...Stop signal detector, 2o...
・Speed control detector, 21... Pedal depression detector,
22...Microcomputer-123...Input interface circuit, 24...Output interface circuit, 25.26.27...Lunoid drive circuit, 28
... Electromagnetic brake circuit for stopping the motor, 29 ... Electromagnetic clutch circuit for transmitting motor power, 30 ... Push-up plate, 31 ... Upper shaft, 32 ... Push-up eccentric, 33
... Thrust-up rondo, 34... Thrust-up crank, 35
... Thrust-up crank eccentric, 36... Thrust-up crankshaft, 37... Thrust-up link, 38... Thrust-up shaft arm, 39... Thrust-up shaft, 4o... Fabric, 40a.・
・Dough edge, 40b...Contacting part, 41...Dough presser, 42 Pa・Knee lever, 43...Knee lever shaft, 4
4... Knee lever shaft arm, 45... Presser shaft link, 46
... Presser shaft arm, 47 River presser shaft, 48 ... Arrow, 49
... Throat plate, 50... U-shaped groove, 51... Small gear, 52... Large gear, 53... Roller, 54.55...
・Arrow, 56...Curved needle. Applicant Daiwa Sewing Machine Manufacturing Co., Ltd. (and 2 others) m/Figure M2 Figure 5 Figure 0 ESQ Figure 9 Figure 1stt Figure 8

Claims (1)

[Scope of Claims] 1. At the sewing end of the scoop stitch sewing machine, one ring is made from the fabric by mechanically sewing the scoop stitch portion of the fabric by lowering the seam forming time, and then sewing the fabric. A method for preventing unraveling at the end of sewing of a scoop stitch sewing machine, which comprises raising the sewing thread to a predetermined position, performing scoop stitching again, passing the thread end through the stray ring, and further cutting and pulling and tightening the thread end. . 2. The fabric presser foot and the push-up plate of the known scoop stitch sewing machine are not linked by a knee lever, but are moved up and down independently, and a knee switch is installed in place of the knee lever, and the knee switch is installed. And when the pedal is depressed, neutralized, turned back, etc., the dough is pressed and pressed through the control circuit.1. Connect the wires to activate the push-up plate, automatic thread cutting device, sewing machine, -cooking, etc., and then turn the sewing machine two more times each time you press the button when sewing is finished. A device for preventing unraveling at the end of sewing of a scoop-stitch ζ-thin, which is characterized in that it makes a scoop-stitch that passes through the ring in the next rotation. 3. A solenoid for lowering the fabric presser is installed via a connecting chain at the tip of the shaft arm of the presser knee lever that is linked to the fabric presser of a known scoop stitch sewing machine, and the upper part is attached to the side surface of a large gear that meshes with a small gear fixed to the crankshaft. An electromagnetic induction motor with a built-in clutch and brake is used as the sewing machine motor, and a position detector for detecting the needle position and rotational speed is attached to the upper shaft, replacing the knee lever of the known scoop stitch sewing machine. A knee switch is attached to the seat, and a detector is provided in conjunction with each pedal to detect the pedal depression, neutral position, and pedal depression, and the position detector, knee switch, and pedal motion detector are controlled by a microcomputer. The solenoid for lowering the fabric presser, the solenoid for retracting the push-up plate, the automatic thread cutting device, the electromagnetic brake circuit for stopping the sewing machine motor, and the electromagnetic clutch circuit for transmitting the motor are connected through the Step down and then step back, and for the first rotation, move the push-up board backward to form a ring.Next tV = rotation 7
Raise the push-up plate and perform a scoop stitch that passes through the ring. When the needle stops at the top dead center, the automatic thread cutting device will operate after a certain period of time, and the push-up plate will move back by pressing the knee switch. The special feature is that the dough presser is lowered at the same time.
A manufacturing device that prevents unraveling at the end of sewing.