JPS6215036Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an automatic tacking device for a sewing machine that can automatically perform tacking work during sewing operations on a sewing machine.

Conventionally, when sewing with a sewing machine, the worker manually operated the fabric feed reversing mechanism of the sewing machine to perform the tacking work to prevent the threads from fraying at the beginning and end of the sewing. It is necessary to sew back and forth as much as a needle, and the work is very complicated and requires a large amount of work time and a high degree of skill.
Hand-operating the cloth feed reversing mechanism and tacking stitches by operating the foot pedal inevitably have the disadvantage that the lengths are uneven and the back and forth stitches are uneven.

This invention was made to eliminate the above-mentioned drawbacks of the conventional methods.It automates a series of manual operations, and furthermore, this operation command is completely automatically executed without requiring any special operations by the operator. At the same time, the number of stitches for tacking stitches can be controlled by counting the number of stitches to any predetermined amount, so that tacking stitches can be performed accurately and with a good finish without uneven seams.Furthermore, the thread can be automatically trimmed following the tacking stitches. The present invention provides an automatic tacking device for a sewing machine that can perform tacking.

An embodiment of this invention will be described below. In Fig. 1, 1 is a sewing machine body, 101 is a sewing machine needle, 102 is a cloth presser foot, 103 is a cloth feeding device, 10
4 is a return lever of the cloth feed reversing mechanism, 105 is an electromagnet for the return lever for its operation, 106 is a thread trimming electromagnet for automatic thread trimming operation of the sewing machine, 107 is a sewing machine pulley, 108 is a sewing machine table, and 109 is a V-belt. be. Furthermore, the sewing machine needle 101 is connected to the pulley 10.
7 reciprocates once per rotation, and the cloth feeding device 103
When the sewing machine needle 101 is above the table 108, it moves periodically with the movement of the needle to feed the cloth at a constant pitch.

Further, when the electromagnet 105 for reverse stitching is energized, the lever 104 is operated downward, and the cloth feeding device 103 feeds the cloth in the reverse direction by the cloth feeding reverse movement mechanism.

2 is a sewing machine needle position detection device that detects the vertical position of the sewing machine needle; 201 and 202 are proximity switches supported by the sewing machine head; and 203 and 204 are metal pieces that rotate together with the sewing machine pulley 107, Proximity switch 201 detects the upper position of sewing machine needle 101 by metal piece 203, and proximity switch 202 detects the lower position of sewing machine needle 101 by metal piece 204, and the sewing machine needle moves up and down by either of them. It can send out an electrical signal every time it is activated.

3 is a clutch motor with a well-known fixed position stop device that drives the sewing machine 1 and stops the sewing machine needle at a predetermined position when stopped; 301 is a main motor that is constantly driven at high speed; 302 is a flywheel that rotates integrally with this motor;
303 is a clutch wheel, which is normally pulled back to the right in the figure by a return spring 304 so as not to come into contact with the flywheel 302;
When the operator depresses the foot pedal 307 forward using the clutch lever 306, the foot pedal 307 moves to the left in the figure during the depressing process, communicates with the flywheel 302, and drives the output pulley 308 at high speed. Reference numeral 309 denotes an auxiliary motor that positions and drives the sewing machine needle at a predetermined position before stopping, and its rotation is decelerated by a reduction gear device 310, and when the clutch wheel 303 is in a normal position, the brake wheel 311 connected to this is connected to the main motor 30.
Drive at a low speed of several tenths of 1. 312 is an electromagnetic brake that performs the final braking stop; 313,
314 is a micro switch that is activated depending on the operator's operating state of the foot pedal 307;
314 is a switch that is activated when the foot pedal 307 is operated from the neutral position N to the forward depression position F, and 314 is a switch that is activated when the foot pedal 307 is operated from the neutral position N to the backward depression position R.

4 is a drive control device provided between the clutch motor 3 and the sewing machine 1, and 401 is a drive control device that controls the main motor 301 only when the sewing machine 1 is in tacking stitch operation.
An intermediate motor driven at a fraction of the speed of 4
02 is this motor shaft, 403 is a pulley directly connected to this motor shaft, and is connected to the sewing machine pulley 107 by the belt 109 mentioned above. Also, 404 is an electromagnetic clutch, 405 is a stator of this electromagnetic clutch, and 40
6 is a rotating magnetic pole, which is directly connected to the motor shaft 402. 407 is an amateur and 408 is a pulley, but this amateur 407 is a pulley 408.
are connected freely in the axial direction using splines, etc.
The pulley 408 is rotatably supported on the motor shaft 402 by a bearing or the like, and is connected to the output pulley 308 of the clutch motor 3 by a belt 409. When the electromagnetic clutch 404 is not energized, the clutch motor 3 is driven. However, when the electromagnetic clutch 404 is energized, the pulley 408 idles and the sewing machine 1 is not driven.
7 is connected to a rotating magnetic pole 406, and the drive of the clutch motor 3 is transmitted to the sewing machine 1 via a pulley 408 and a motor shaft 402.

5 is a control box, 501 is a preset counter for controlling the amount of tacking, and 502 is its setting dial.

Next, the control circuit will be explained with reference to FIG.

503 is a commercial power supply, and on that line are the stator coil (SM) of the auxiliary motor 309 and the stator coil (MM) of the intermediate motor 401, and normally open contacts RA ₂₄ and RA ₉₂ of relays RA ₂ and RA ₉ , which will be described later. are connected via and controlled and driven by these relays. 504 is a transformer, 505 is a full-wave rectifier, R ₁ is a resistor, and C ₁ is a capacitor. This capacitor C ₁ is charged and deactivated when relay RA ₄ is energized by contact RA ₄₁ of relay RA ₄ , which will be described later. Diode at the moment
It discharges through _D1 and energizes relay _RA1 , which will be described later. In addition, a normally open contact RA ₃₁ of a relay RA ₃ (described later) and a resistor R ₅ are connected in parallel with this, and the excess charge charged in the capacitor C ₁ is discharged from this. C ₂ is a capacitor, to which switch S ₁ of the micro switch 313 is connected, and to this normally open terminal are relays RA ₂ , which will be described later.
A relay RA ₁ for starting the tacking operation is connected through contacts RA ₂₅ and RA ₄₂ of RA ₄ . Then, when the operator depresses the pedal 307 to the forward F position, the switch _S1 is operated, the capacitor _C1 is charged, and the relay _RA1 is also energized. TR ₁ is a transistor, which controls relay RA ₂ for fixed position stop control.
The base of the transistor TR ₁ is connected to the normally closed terminal of the switch S ₁ via a resistor R ₄ and a diode D ₂ . In addition, the normally open contact RA ₈₅ of a relay RA ₈ (described later) and a resistor R ₃ are connected to _{the normally} closed terminal of the switch S 1, and the capacitor C ₂ is connected at a predetermined time even when the switch S ₁ is not operating.
is charged. 2 is the above-mentioned detector; 201 is a proximity switch for detecting the upper position of the sewing machine needle 101;
Reference numeral 202 denotes proximity switches for detecting the lower position. These proximity switches constantly oscillate, and when the metal pieces 203 and 204 approach each other, the transistors TR ₂ and TR ₃ built into each become non-conductive. First, the output line of the proximity switch 202 for detecting the lower position is connected to the normally open contact RA ₂₁ of the relay RA ₂ and the relay described later.
It is connected between the resistor R ₄ and the diode D ₂ through the normally closed terminal of the contact RA ₅₁ of RA ₅ , which controls the transistor TR ₁ at a given time. Further, the output line of the proximity switch 201 for detecting the upper position is first connected to the normally open terminal of the contact RA ₅₁ , and similarly controls the transistor TR ₁ at a predetermined time, as well as the normally open contacts RA ₆₁ of the relays RA ₆ and RA ₈ , which will be described later. , RA ₈₁ to the input terminal of the preset counter PC501, and supplies a pulse to the preset counter PC501 at a predetermined time every time the sewing machine needle 101 reaches the upper position. The preset counter 501 adds up the pulses supplied from the proximity switch 201 as described above, and when the preset value is reached, it generates a voltage for several tens of milliseconds, energizes the relay RA ₃ , and at the same time sets the count value to 0. Return to self-reset.

Switch S ₂ of the micro switch 314 is activated when the foot pedal 307 is pressed back to the rear R position.
connects the normally open contact RA ₁₁ of relay RA ₁ to its normally closed terminal
and the relay RA ₄ is connected through a parallel circuit of its normally open terminal RA ₄₃ . In addition, the normally open terminal of switch S ₂ is connected to the normally closed contacts RA ₈ of relays RA ₈ and RA ₆ , which will be described later.
RA ₆₂ , normally closed contact RA ₁₂ of relay RA ₁ , and relay
Relay RA ₅ is connected via a parallel circuit of normally open contact RA ₂₂ of RA ₂ and its own normally open contact RA ₅₂ . Note that this relay RA ₅ is connected in parallel with a capacitor C ₃ , so there is a delay in turning on for several tens of milliseconds. RA ₆ , RA ₇ , RA ₈ are relay RA ₁ for start of tacking stitch operation and preset counter 5
A relay operated by relay RA ₃ energized by relay RA 3, which has a normally open contact RA ₁₃ of relay RA ₁ , a contact RA ₃₂ of relay RA ₃ , and its own contacts RA ₈₃ , RA ₆₃ ,
RA ₇₁ , RA ₇₂ and diodes D ₃ and D ₄ are connected and controlled. Then, relay RA ₆ activates relay RA ₁ , which issues the tacking stitch operation command, and counter 501.
is energized until reaching the set value and relay RA ₃ is activated, and relay RA ₈ is energized again from that point onwards.
RA ₃ is energized until activated. RA ₉ is a relay that controls the intermediate motor 401 and the return lever electromagnet 105, and the normally open contacts RA ₆₄ of relays RA ₆ and RA ₈ ,
RA ₈₄ and diodes D ₅ and D ₆ are connected and controlled.
KC is controlled by the coil of the return lever electromagnet 105 connected to the contacts RA ₆₄ and RA ₈₄ and the contact RA ₄₄ of the relay RA ₄ . CC is the above electromagnetic clutch 40
5 coils, controlled by the normally closed contacts RA ₉₁ of the relay RA ₉ .

BC is controlled by the coil of the electromagnetic brake 312 and the normally closed terminal of contact RA ₂₃ of relay RA ₂ . or
TC is the coil of the thread trimming electromagnet 106, the normally open terminal of the contact RA ₂₃ , and the normally open contact of the relay RA ₅ .
Controlled by RA ₅₃ .

Next, the operation will be explained with reference to FIG.

First, when the power is turned on, the clutch 405 and the brake 312 are energized. Then, at point a, the worker presses the foot pedal 30 in exactly the same way as in normal sewing work.
7 from the neutral N position to the forward F position, the clutch wheel 303 is connected to the flywheel 302 which rotates at high speed, but at the same time switch S ₁ is activated and the relay is activated.
RA ₁ is energized, which causes the relay to
RA ₄ and RA ₆ are energized, relay RA ₉ is energized,
The normally closed contact RA ₉₁ is opened, the electromagnetic clutch 405 is deenergized, and the driving force of the main motor 301 is not transmitted to the sewing machine 1. Then, the intermediate motor MM is energized, and the sewing machine 1 is thereby driven at a medium speed that is a fraction of the normal sewing speed and faster than the low speed described later (the speed is almost constant from the time of ax. The tacking speed mentioned above refers to this medium speed.) The electromagnet 105 for the reverse lever is a relay.
Since RA ₄ is energized, it is not energized. Therefore, the sewing machine 1 first starts the sewing operation by feeding in the forward direction. On the other hand, at the same time, a pulse is supplied from the proximity switch 201 to the counter 501 through the contact RA ₆₁ every time the sewing machine needle 101 moves up and down, and the counter PC counts. Furthermore, relay RA ₁ is a relay.
Since RA ₄ is energized, it is deenergized by opening contact RA ₄₂ , and capacitor C ₁ is charged by activation of contact RA ₄₁ . When a predetermined number of stitches have been sewn in the forward direction at time b, the counter 501 counts up to the set value and energizes the relay RA ₃ . This de-energizes relay RA ₆ and turns on the relay instead.
RA ₈ is activated. Therefore, the input circuits of the electromagnetic clutches C, C, intermediate motors M, M, and counter 501 are held as they are, and the return lever solenoid 105 is newly energized by the contact RA ₈₄ , and the cloth feed device 103 of the sewing machine is reversed. The working fabric is fed in the opposite direction and reverse stitching is performed.

The same predetermined number of stitches are sewn in reverse, and the tacking stitch at the beginning of the sewing is completed.When time c is reached, the counter 501 reaches the set value again and the relay RA ₃ is energized. Then, the relay RA ₈ is deenergized, the coil KC of the return lever electromagnet 105 is deenergized, the input circuit of the counter 501 is cut off, or the relay
RA ₉ is deenergized, the intermediate motor 401 is deenergized, and at the same time, the electromagnetic clutch 405 is energized and the main motor 301 is deenergized.
The driving force of the clutch plate 303 and the electromagnetic clutch CC
The sewing machine is driven at a high speed that is a normal sewing speed, and normal sewing is performed at a substantially constant speed from the time point cx.

Then, when the operator wants to stop the sewing machine to realign the fabric or change the feeding direction of the fabric during sewing, that is, at point d, the operator returns the sewing machine pedal 307 to the neutral N position as in normal sewing work. , the clutch wheel 303 is separated from the main motor 301 and connected to the brake wheel 311. At the same time, switch
_S1 is turned off, capacitor _C2 is discharged, transistor _TR1 becomes conductive, and relay _RA2 is energized. Then, the electromagnetic brake 312 is deenergized, the speed is decelerated to the point dx, and the auxiliary motor 309 is energized to drive the sewing machine 1 to a low speed of several tenths, that is, a low speed lower than the medium speed (tacking speed). Even after the capacitor _C2 has finished discharging, the transistor _TR1 remains conductive through the transistor _TR2 of the proximity switch 202, and the positioning drive at a low speed is continued.

Then, at time e when the sewing machine needle 101 reaches a predetermined lower position, the transistor TR ₂ of the proximity switch 202 becomes non-conductive, the transistor TR ₁ and the relay RA ₂ are turned off, the auxiliary motor 309 is deenergized, and the electromagnetic brake 312 is activated. The sewing machine 1 suddenly stops at a fixed position.

At point f when sewing starts again, the worker depresses the foot pedal 307 to the forward F position in the same manner as usual, and the clutch wheel 302 is connected to the main motor 301, and at the same time, the switch _S1 is turned on. This time, unlike at point a at the start of sewing, relay RA ₄ has already been energized and contact RA ₄₂ has been switched to the resistor R ₂ side, so relay RA ₁ is not energized. Therefore, the electromagnetic clutch 40
5 remains energized, the sewing machine 1 is suddenly driven at high speed by the main motor 301 (approximately constant speed from the time fx) in exactly the same way as normal sewing without performing a tacking operation.

In this way, stopping and restarting during sewing can be performed in exactly the same way, and normal operation can be performed as many times as desired without performing a tacking operation.

When the required sewing is completed and the sewing is finished by performing the tacking stitch at the end of the sewing, that is, at point g, the operator returns the foot pedal 307 to the neutral N position and further back to the rear R position using the same operation as normal. When you press the button again, switch S ₁ turns OFF and switch S ₂ turns ON, but first, sewing machine 1 is decelerated rapidly (up to point gx) in the same way as at point d, and is driven for positioning at a low speed of several tenths from point h. It is. Also, Switch S ₂ is here for the first time.
Since it is turned on, relay RA ₄ , which has been energized gradually from point a at the beginning of sewing, is deenergized.

When the sewing machine needle 101 reaches a predetermined lower position at time h, the relay is first activated in the same way as at time e.
RA ₂ is deenergized, the auxiliary motor 309 is stopped, and the electromagnetic brake 312 is energized. And at the same time, this time it's a point of contact
Since RA ₂₅ , RA ₄₁ , and RA ₄₂ return to their original closed states, relay RA ₁ is energized by the discharge of capacitor C ₁ , relay RA ₆ is also energized, and electromagnetic clutch 405 is deenergized as at point a. , the intermediate motor 401 is energized, and the sewing machine 1 is driven at the intermediate speed, that is, the tacking speed (hx
After that point, the speed is almost constant). At the same time, this time it's a relay
Since RA ₄ is deenergized, the return lever electromagnet 105 connected by contacts RA ₆₄ and RA ₄₄ is energized. That is, the tacking stitch at the end of sewing is first started with reverse direction feed.

I sewed the specified number of stitches using reverse direction feed.
When the time point is reached, the counter 501 energizes the relay RA ₃ , de-energizes the relay RA ₆ , and energizes the relay RA ₈ , similarly to the time b. Then, the electromagnet 1 for the return lever
05 is deenergized, the feed direction is switched to the forward direction, and tacking stitching with forward feed is started.

The same number of stitches are sewn in the forward direction, and when the sewing machine reaches point j when the reciprocating tacking at the end of sewing is completed, the counter 501 energizes the relay RA ₃ and deenergizes the relay RA ₈ , and the intermediate motor 401 turns on. At the same time, the electromagnetic clutch 405 is energized and the sewing machine 1 is connected to the clutch motor 3 again.
At the same time, the capacitor C ₂ charged by the contact RA ₈₅ between I and J is discharged, the relay RA ₂ is energized, and the auxiliary motor 309 operates the sewing machine at a low speed for positioning.

Then, when the sewing machine needle 101 reaches a predetermined lower position at time h, the relay RA ₂ is deenergized. At this time, while g-k is open, the relay that was prevented by the contacts RA ₈₂ , RA ₆₂ , RA ₁₂ , and RA ₂₂ RA ₅ is energized for the first time. Then contact RA ₅₁ connects transistor TR ₁
The base circuit is connected from the proximity switch 202 for lower position detection to the proximity switch 2 for upper position detection.
01, the relay RA ₂ is energized again, and the auxiliary motor 309 starts driving the needle of the sewing machine 1 half a rotation from the lower position to the upper position. At the same time, the thread trimming electromagnet 106 is energized.

Therefore, the thread cutting operation is performed at the positioning operation speed which is lower than the medium speed (tacking speed).

Then, the thread is cut at a predetermined position by the sewing machine mechanism on the way, and when the sewing machine needle 101 reaches a predetermined upper position, the relay RA ₂ is deenergized and the auxiliary motor 309
stops, and the sewing machine 1 is suddenly stopped by the brake 312 and all operations are completed.

Note that without suddenly stepping back on the sewing machine pedal 307 to the rear R position at point g, the sewing machine needle 10 is set at point h.
1 to the lower position, check the end of the sewing, and then press the pedal 307 to the rear R position and turn the switch S ₂ .
Even if it is turned ON, the tacking work at the end of sewing can be performed in the same way.

As described above, this invention consists of a sewing machine equipped with a mechanism for reversing the direction of cloth feed, a motor for driving this sewing machine, a foot pedal that connects and disconnects the driving force of this motor to the sewing machine, and one part of this foot pedal. When the sewing machine is actuated by depressing in one direction, a first actuator operates for a predetermined period of time in response to the depressing, and causes the sewing machine to operate at a predetermined tacking speed lower than the normal sewing speed. a control device; when the foot pedal is depressed beyond the release position of the pedal in a direction opposite to the one direction after the required sewing is completed, the sewing machine temporarily lowers the tacking stitch speed in response to the pedal depression; After detecting that the positioning speed has reached a lower positioning speed, the sewing machine operates for a predetermined period of time for backtack stitching, operates the sewing machine at a predetermined set backtack speed lower than the normal sewing speed, and then performs thread trimming operation. and a second control device, each of the first control device and the second control device having a control unit that operates the cloth feeding direction reversing mechanism for a required period while the sewing machine is operating at the tacking speed. The preset counter included in the control section performs the required length of tacking stitches at the start and end of sewing by counting the number of stitches, and the tacking stitches are performed at a predetermined setting lower than the normal sewing speed. In addition, the thread trimming operation is configured to be automatically performed at the predetermined positioning speed that is slower than the tacking speed after tacking. There is no delay in the operation of the cloth feed direction reversing mechanism due to delays in the mechanical system, and since the length of the tacking stitch is determined by the number of stitches, it is similar to a timer that controls the number of stitches. In addition, it is possible to obtain good tacking stitches with a stable finish without causing any negative effects such as uneven stitch lengths due to the delay in the operation of the cloth feed direction reversing mechanism. Since the thread cutting operation can then be performed automatically, the operator can omit complicated operation operations and can automatically carry out a series of operations from sewing to tie stitch thread cutting. Furthermore, when the foot pedal is depressed in the opposite direction beyond the release position after the required sewing is completed, the second control device detects that the sewing machine has reached the positioning speed and then returns the sewing machine to the lock stitching speed. Since the sewing machine is automatically operated, even if the foot pedal is quickly depressed in the opposite direction after the required sewing is completed, the number of tacking stitches will not be incorrect due to a delay in the response of the tacking solenoid, etc., and the desired number of correct stitches will be achieved. You can perform tacking stitches with .

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of this invention, FIG. 2 is an electrical control circuit diagram thereof, and FIG. 3 is an explanatory diagram of its operation. In the drawings, the same reference numerals indicate the same parts, 1 is the sewing machine body, 2 is the sewing machine needle position detection device, 3 is the clutch motor, 4 is the drive control device,
5 is a control box, 101 is a sewing machine needle, 102 is a presser foot, 103 is a fabric feeding device, 307 is a foot pedal,
313 is a depression detection switch, 314 is a depression detection switch, and RA ₁ , RA ₂ , and RA ₄ are relays.

Claims (1)

[Scope of utility model registration request] A sewing machine equipped with a cloth feed direction reversing mechanism, a motor for driving this sewing machine, a foot pedal that connects and disconnects the driving force of this motor to the sewing machine, and a foot pedal that is stepped in one direction. a first control device that operates for a predetermined period of time in response to a depression when the sewing machine is driven, and causes the sewing machine to operate at a predetermined tacking speed lower than a normal sewing speed; After that, when the foot pedal is pressed in a direction opposite to the one direction beyond the release position of the foot pedal, the sewing machine temporarily reaches a positioning speed lower than the tacking speed in response to the foot pedal being pressed in a direction opposite to the one direction. After detecting this, a second control device operates for a predetermined period of time for tacking, operates the sewing machine at a predetermined tacking speed lower than the normal sewing speed, and then performs a thread trimming operation; The first control device and the second control device each include a control unit that operates the cloth feed direction reversing mechanism for a required period while the sewing machine is operating at the tacking speed, and the first control device and the second control device each include a control unit that operates the cloth feeding direction reversing mechanism for a required period of time while the sewing machine is operating at the tacking speed, and At the end of sewing, the required length of tacking is performed by counting the number of stitches using a preset counter included in the control section, and the tacking is performed at a predetermined tacking speed that is lower than the normal sewing speed. An automatic tacking device for a sewing machine, wherein the thread trimming operation is automatically performed at a predetermined positioning speed lower than the end tacking speed of the tacking stitch.