JPS5830063Y2 - 2-needle sewing device - Google Patents

Description

[Detailed explanation of the invention] This invention changes from two-needle operation to one-needle operation or one-needle operation.
This invention relates to a two-needle sewing device that performs sewing by switching from a single-needle operation to a two-needle operation.

Conventionally, when sewing the corners of a workpiece with this type of device, the sewing machine mechanism was switched from two needles to one needle, and the sewing machine was rotated at low speed using a needle drive circuit with a counter to sew only the set number of stitches. 1. I was sewing with wooden nails.

Therefore, when sewing corners, if you want to make the number of stitches on each side of the corner different, the disadvantage is that you have to change the number of stitches set on the counter each time you finish sewing one side of the corner. there were.

This invention was devised to eliminate such drawbacks, and by installing two dedicated counters for sewing one side and one side of the corner, the number of stitches to be sewn on one side and one side of the corner can be reduced. The purpose of this invention is to provide a highly efficient two-needle sewing device in which the counting setting only needs to be made once at the beginning even when sewing items with different values.

An embodiment of this invention will be described below.

In Figure 1, 1 is a two-needle sewing machine, 2 is a table, and 3 is a two-needle sewing machine.
is a pulley, 4 is a normal needle position detector that detects the needle position in order to stop the needle 5 in the lower position, and 6 is a main motor that operates the two-needle sewing machine at high speed. (not shown), the two-needle sewing machine 1 is operated at high speed or stopped.

Reference numeral 8 denotes an auxiliary motor that operates the sewing machine 1 at a low speed so that the needle position is detected by the needle position detector 4 when the operation of the two-needle sewing machine 1 is stopped, and 9 houses an operation control circuit for the two-needle sewing machine 1. The control box 10 is a lever-shaped switching device for switching from two-needle operation to single-needle operation, or from one-needle operation to two-needle operation, as shown in Figures 2 and 3. It is rotatably attached to the sewing machine 1.

Moreover, when this switching device 10 is in the position shown in FIG.
When the switching device 10 is turned either left or right from the position of the switching device 10, it becomes a single-needle operation. For example, when the switching device 10 is turned to the right as shown in FIG. It becomes needle operation.

Next, the control circuit will be explained.

Figure 8 represents the control circuit using logic symbols.23.2
4, 25.47 are all waveform shaping circuits that shape the waveform of signal input, 26.27.28 are well-known AND circuits, 3
0 is a counter for counting the number of stitches on the first side in corner sewing, 31 is a counter for counting the number of stitches on the other side, 32, 33, 34 is a flip-flop circuit, 2
9, 42, and 49 are well-known OR circuits; 35 is a single-shot multivibrator that generates a short pulse only once when the input voltage changes to a high level; and 143 and 44 are outputs that delay the input signal. The delay circuit 18 is a microswitch that is operated by the movement of the petal door.Normally, the contact is closed, but when the petal door is kicked back to the position shown in Fig. 4, 7a, the contact opens. It is a switch that is operated when sewing corners.

45 is a similar microswitch, and the contact opens when the pedal is depressed to the position shown in FIG. 4, 70.

20, 21, 22, and 46 are resistors, and 4 is the needle position detector described above, details of which are shown in FIGS. 6 and 7.

Here, 13 is a slip ring for detecting the measured position, which is composed of a conductor part 13a and a non-conductor part 13b.

Reference numerals 15 and 16 are carbon brushes that are in constant contact with the slip ring 13.

The circuit connecting the carbon brush 15, the slip ring 13a, and the carbon brush 16 is electrically conductive when the needle is in a position other than the upper position, but is cut off by the non-conductive part 13b when the needle is in the upper position. It is something that

When the needle is in a position other than the upper position, the potential of the point on the brush 15 is the same potential as the ground, but when the needle is in the upper position, the potential of the brush 15 is the same as that of the ground.
The potential at point 5 is the same potential as the power supply.

Therefore, a high level signal (hereinafter referred to as H) is applied to the input of the shaping circuit 23.

14 is a slip ring for detecting the needle lower position, and the conductor portion 1
4a, non-conductor portion 14b and carbon brush 16.17
When the needle reaches the lower position, H is added to the input of the shaping circuit 24.

36 is an auxiliary motor drive relay, which is driven by a transistor 40.

37 is a diode for protecting the transistor 40, 1
Reference numeral 9 denotes a brake actuating electromagnet, which is driven by a transistor 41.

38 is a diode for protecting the transistor 41;
9 is a three-phase AC power supply, and 8 is an auxiliary motor, which is driven and stopped by opening and closing contacts 36 a and 36 b of a relay 36 .

In the twin-needle sewing device configured as described above, when sewing the corners of the workpiece by a predetermined number of counts, the twin needles are used until the corner sewing start position 100 is sewn, as shown in Fig. 5. The sewing machine is operated at high speed, and when the sewing progresses to this position 100, the right needle bar of the two needles is stopped by the switching device 10 in the sewing machine head.

Then, as shown in FIG. 4, the Petalua is turned back from the neutral position 7b and operated to the position 7a.

Then, the switch 18 is operated, its contacts are opened, and the symbol H is transmitted to the input of the shaping circuit 25.

Although this signal contains noise as shown in FIG. 9 due to contact chattering of the switch 18, etc., it is shaped by the shaping circuit 25 shown in FIG.

(Output of FIG. 9, 25) At the rising edge of this signal, an H pulse is generated from the single-shot multivibrator (FIG. 8, 35).

(Output of FIG. 9, 35) The flip-flop 33 is set by this pulse, and the output of the flip-flop 33 becomes H.

Furthermore, this H signal passes through the OR circuit 49 and sets the flip-flop 34.

This flip-flop is a flip-flop for driving an auxiliary motor.

That is, the output of 34 is applied to the base of transistor 40, which makes transistor 40 conductive, activating relay 36 and closing its contacts 36a, 3.
In order to close 6b, the auxiliary motor 8 is driven.

Now, the output of the flip-flop 33 is also applied to the AND circuit 26, so that the signal from the other input of 26 can pass through 26.

That is, the counted position detection signal (stitch number signal) of the detector 4 is added to the input of the front touch AND circuit 26.

Now, since the H input is added to 26's single-man power, the recorded position signal is output from 26.

This signal is applied to AND circuits 27 and 28, respectively.

Now, the flip-flop 32 is in the initial state (reset state), and the output Q of the flip-flop 32 outputs an H signal, and the output Q of the flip-flop 32 outputs an H signal. This means that the L signal is added to.

Therefore, only the AND circuit 27 allows the needle up position signal to pass through.

This counted position signal, ie, the number of stitches, is then added to the clock input of the counter 30, and the counter 30 counts the circuits (number of stitches) of the sewing machine.

Now, when the number of sewing stitches for the first side (the part from 100 to 200 in Fig. 5) is set to 4 in corner sewing, the count setting switch 11 is set to the output 4 of the counter 30 as shown in Fig. 8. When the sewing machine is set at the counter 30, the sewing machine is sewing at low speed with a single needle driven by the auxiliary motor, and the fourth counted position signal is added to the clock input of the counter 30, the output 4 of the counter 30 becomes H.
Generate a signal.

This signal passes through the delay circuit 43 and is transmitted to the reset input of the counter 30 with a time delay.

As a result, 30 is reset by the signal it has issued and returns to its initial state.

With this, output 4 of 30 also returns to L.

Therefore, the pulse width of the H signal of output 4 is determined by the time delayed by the delay circuit 43.

This pulse is also added to the set input of flip-flop 32, setting 32, so the Q output of 32 is H,
Q output becomes L.

Further, the output signal of the counter 30 passes through an OR circuit 29 to reset the flip-flop 33.

Before this, the set input of the flip-flop 34 was at H, and the needle down position signal was added to the reset input.

That is, when the needle is in the lower position, an H signal is applied to the reset input of the flip-flop 34, and at other times, an L signal is applied to the reset input of the flip-flop 34.

Since the flip-flop 34 gives priority to the set input, it maintains the set state even if the reset input is set to H when the set input is set to H.

Then, as described above, when an L signal is applied to the set input of the flip-flop 34 due to the fourth counted position signal, if an H signal is applied to the reset input of the flip-flop 34, 34 is reset.

From position 100 in Fig. 5, sew only 4 stitches using only the left needle. From then on, when the needle comes to the down position, the needle down position signal H is added to the manual reset of flip-flop 34, so 34 is the first one. The state returns to the state, and the Q output becomes H.

Therefore, transistor 40 becomes non-conductive and relay 36
is deenergized, its contacts 36a and 36b are opened, and the auxiliary motor 8 is stopped from being energized.

Further, the transistor 41 becomes conductive, and the brake coil 19 is energized, so that a brake (not shown) is applied to the motor 8, and the sewing machine stops at the needle down position.

Thus, after sewing 4 stitches with the left needle and stopping at the lower position,
When the cloth is rotated 90 degrees around the position shown in Fig. 200, the petal is returned to the neutral position (Fig. 4, 7b), and then turned again to the position shown in Fig. 4, 7a. When opened, an H signal is applied to the set input of flip-flop 33, setting 33, energizing relay 36 again, and driving auxiliary motor 8.

At the same time, the brake 19 is also deenergized.

In this way, when the sewing machine rotates at a low speed again, the needle up position signal is transmitted by the detector 13 to the next rotation through the AND circuit 26 as before.

Now, as mentioned earlier, since the flip-flop 32 is set, the one-man power of the AND circuit 27 is L, and the one-man power of the AND circuit 28 is H, so the above needle up position signal is sent only to the AND circuit 28. It passes through and enters the clock input of the counter 31, but the clock input of the counter 30 is not affected.

This counter 31 counts the number of stitches on the other side of corner sewing.

Now, set the number of stitches on the other side to 6, and set the count setting switch 12.
is set to output 6 of the counter 31.

In this way, when the sewing machine pulley rotates 6 times, the 6th needle up position signal is input to the clock of counter 31, and 31
An H signal is generated from the output 6 of .

This signal passes through the OR circuit 29 to the flip-flop 33.
It joins the reset input of , and resets 33.

33's Q output is L, and the set input of the flip-flop 34 is L, and the subsequent needle down position signal causes the flip-flop 34. The beam is set.

Therefore, when the sewing machine pulley rotates 6 times, the auxiliary motor 8
is de-energized and the brake 19 is applied, so the sewing machine stops working at the needle down position.

Then, since the output signal of the counter 31 is added to its own reset input and reset itself, the signal at the output 6 of the counter 31 returns to L.

Further, the output signal of the counter 31 is further processed by a flip-flop.

It also adds to the reset input of 32 and resets 32 to return it to its initial state.

In this way, 6 stitches are sewn from the position 200 to the position 300 in Fig. 5 using the left needle, and after stopping at the needle down position, the third
The needle bar switching device shown in FIG. 10 is returned to the neutral position, the two-needle operation is resumed, and normal two-needle sewing is continued.

As described above, according to this invention, when sewing corners, two stitch counting circuits are provided exclusively for sewing two sides of the corner, and the amount of operation of the needle drive motor is limited to automatically perform single-needle sewing. Since the sewing machine is made to stop, even when the number of sewing stitches per side of the corner portion is different, extremely highly efficient sewing work can be performed.

[BRIEF DESCRIPTION OF THE DRAWINGS] The figures show one embodiment of this invention. Figure 1 is a perspective view of the sewing machine, Figure 2 is a front view of the sewing machine when using two needles, and Figure 3 is a front view of the sewing machine with two needles. is a front view of the sewing machine when using a single needle, Fig. 4 is a diagram of the operation of the petal, Fig. 5 is an explanatory diagram of corner sewing, and Figs. 6 and 7 are front views of the needle position detector and counting detector. FIG. 8 is a control circuit diagram, and FIG. 9 is a pulse diagram showing control timing during corner sewing. In the figure, 1 is a two-needle sewing machine, 4 is a needle position detector, 6 is a main motor, 7 is a petal, 8 is an auxiliary motor, 10 is a switching device, 18.45 is a micro switch, 23, 24, 25.
47 is a waveform shaping circuit angle 30, 31 is a counter, 11.
12 is a stitch number setting switch, 35 is a single-shot multivibrator, 144 is a delay circuit, 26 is an AND circuit, and 29 is an OR circuit.

Claims (1)

[Scope of utility model registration request] For straight sections to be sewn with two needles and corners to be sewn with one needle, there is a switching device that selects between twin needle stitching and single needle stitching, and a state in which this switching device is switched to single needle stitching. First and second stitch count circuits that are input to the control circuit of the sewing machine needle drive motor, a switch that gives a command to start operation of the sewing machine needle drive motor, and a needle position detector that detects the position of the sewing machine needle. The first stitch number counting circuit has an output circuit connected to its own reset input via a first delay circuit, and the sewing machine needle driving motor starts operating in response to a command from the switch. When sewing of one side of the corner is started, the count is counted based on the detection signal from the needle position detector, and when the count reaches a predetermined value, a stop signal is sent to the sewing machine needle drive motor. The second stitch number counting circuit is configured such that its output circuit is connected to its own reset input via a second delay circuit, and the second stitch number counting circuit is connected to its own reset input via a second delay circuit.
If, after the stitch count circuit has been reset, a command is issued from the switch and the operation of the sewing machine needle drive motor is started to start sewing the other side of the corner, the signal from the needle position detector is Two-needle sewing machine that counts the number of stitches based on a detection signal, outputs a stop signal for a sewing machine needle drive motor when the count reaches a predetermined value, and resets itself. Device.