JPS6115718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a sewing machine, and particularly to a control circuit suitable for use in a sewing machine equipped with an automatic tacking device.

The details of this invention will be explained below with reference to the drawings. 1st
The figure is an explanatory diagram showing the overall general configuration of a sewing machine with an automatic tacking device, in which the drive machine, that is, the electric motor 10
1 and the sewing machine 102 are connected by a belt 103. The sewing machine 102 includes a position detector 105 for detecting needle position and a frequency generator 10 for detecting speed.
4 is installed.

As a control device, a drive machine, that is, an electric motor 101
Motor speed control circuit 106 that controls the speed of
, a sewing machine operation control circuit 107 that controls various operations of the sewing machine, and a petal command voltage and operation signal circuit 108 that issues start/stop and speed control commands for the sewing machine using a pedal 109 attached to the sewing machine table (not shown). Furthermore, there is an external control circuit 110 including switches for selecting various sewing patterns, and these are housed in one or two control boxes (not shown).

In the above configuration, a power supply is connected to the electric motor 101, and the external control circuit 11
By setting the selection switch 0 (described later based on FIG. 4) and operating the petal 109, the sewing machine rotation speed and the forward and backward feed of the sewing material as shown in FIG. This results in a sewing pattern like the one shown below. Note that A in FIG. 2 shows the case of pattern d in FIG. 3, and B in FIG. 2 shows the case of pattern e in FIG. 3. Patterns b to d in Figure 3 show turning stitches to prevent the thread from fraying during sewing, and generally about 3 to 4 stitches of tacking stitches are performed, but in the case of pattern e, sewing It is a folded stitch used for fixing things, and there are 2 stitches, such as 10 or more stitches to several 10 stitches of folded stitches.
It is common to set the number of stitches in the digit.

Next, the details of the parts related to this invention will be explained with reference to FIG. 4. 1 to 4 are thumbwheel switches (hereinafter referred to as DSW) for setting the number of stitches, RS is a changeover switch for changing the sewing pattern, and CP is a changeover switch for changing the sewing pattern. This is a clock pulse input synchronized with the operation, and is a signal from a position detector 105 attached to the sewing machine shaft. S ₁ and S ₂ are operation signals of the pedal 109, with S ₁ being a stepping signal from the pedal 109, and S ₂ being a kicking signal. R is an initial reset signal when the internal logic circuit is powered on and a reset signal when work is completed; 5 to 8 are BCD counters that count the number of stitches;
9-19 are AND circuits, 20-25 are NOT circuits, 26-31 are OR (0R) circuits, 3
2 to 37 are negative OR (NR) circuits, 38 to 40
is a reset flip-flop (hereinafter referred to as R-) that stores sewing pattern operations.
(abbreviated as SF/F), 41 to 43 are data flip-flops (hereinafter referred to as D-F/F) that store the completion of stitch counting.
), 44 is an exclusive OR circuit, and 45 is a third
A master-slave flip-flop (hereinafter abbreviated as J-KF/F) 46 stores the repetition of pattern e in the figure and switches between forward and backward movement, and 46 outputs various sewing machine control signals according to the output of the logic circuit described above. A decoder circuit for conversion, A to E are control outputs for controlling the sewing machine, 47 to 52 are resistors, 53 to 68 are diodes, and 69 is a capacitor.

This invention is constructed as described above, and its operation will be explained by, for example, setting the pattern changeover switch RS to pattern d, and setting DSW1 to pattern changeover switch RS.
~4 corresponds to A to D in Figure 3 (DSW1 in Figure 4)
~4 and A to D in Figure 3, 1 is B and 2 is A
, 3 corresponds to D, and 4 corresponds to C)
If you press the pedal 109 in line with the desired number of stitches, for example "3," this will cause the pedal depression signal to be activated.
When _S1 becomes L (zero potential), R-SF/F38 is set, NOR element 35 and OR element 27 operate, counters 5 and 6 become active, and clock pulse CP is output from AND element 13 and OR element 28. When the counter 6 enters and counts the number of stitches set in DSW2, D-
The F/F 42 operates and A in FIG. 3 is completed. Next, the clock pulse CP enters the counter 5 from the AND element 10 and the OR element 26, counts the number of stitches set in the DSW 1, operates the D-F/F 41, and enters the decoder circuit 46, ending B in Fig. 3. Complete the sewing operation. Thereafter, sewing of an arbitrary length G is performed. Next, when you kick back Petal 109, you will receive a stepping signal.
_S1 becomes H (high potential), the kickback signal _S2 becomes L this time, and R-SF/F39 is set. NOR element 36 and OR element 30 operate, counters 7 and 8 become active, and clock pulse CP is input from AND element 17 and OR element 31 to counter 8, and when the number of stitches set in DSW 4 is counted, D-F/F4
3 operates, and C in FIG. 3 is completed. then AND
When the clock pulse CP from the element 14 and the OR element 29 enters the counter 7 and counts the number of stitches set in the DSW 3, step D in FIG. Then, when the thread cutting operation is completed and all operations are completed, the R-SF/Fs 38 and 39 are reset by the reset signal R to prepare for the next operation. Note that the NOT elements 20, 22, 2
3 and 25 are for storing the count up of counters 5-8.

Next, turn the pattern changeover switch RS to pattern e.
To explain the case where it is set to , petal 10
By depressing 9, the depressing signal _S1 becomes L and R
- SF/F40 is reset, NOR element 35,
36 and OR element 27 operate, and the counter 5,
6 becomes active, and at the same time J-KF/F45 and
AND elements 9, 12, and 16 also become active.

Count pulse CP is AND element 9, OR element 2
When it enters the counter 5 lower than 6 and progresses from 0 to 9, a carry pulse passes through element 12 and OR element 28,
When the upper counter 6 counts up to the number of stitches set by DSW 1 and 2, it goes to the J input of J-KF/F45 via AND element 11 and goes to resistors 51 and 5.
2. A differential pulse synchronized with the clock pulse CP is created by the capacitor 69 and the exclusive OR circuit 44, and J-KF/F 45 is set. When this is set, the counter 5,
6 is reset, and at the same time counters 7 and 8 become active through NOR element 37 and OR element 30, and the clock pulse CP enters AND element 9 and counter 7 which is lower than OR element 29, and when it advances from 0 to 9, the carry pulse becomes AND. It passes through the elements 16 and 31 and enters the upper counter 8. Then, when the number of stitches set by DSW3 and DSW 4 is counted, J is passed through AND element 15.
- Enters K input of KF/F45 and J-
KF/F45 is reset by differential pulse,
Counters 5 and 6 become active again. The above operations are continuously repeated while the pedal 109 is depressed.

According to the present invention, as described above, a sewing machine having a tacking function, a driving machine for driving this sewing machine, a speed control circuit for driving this driving machine, and a control circuit for generating different sewing patterns are provided. The sewing machine is equipped with a stitch count circuit, that is, counters 5 to 8, which can be switched according to different sewing patterns, and the stitch count can be performed singly or in combination of multiple digits. It has a small number of parts, is easy to operate, can perform multi-functional sewing, and is very effective in practical use.

Further, according to the present invention, a differential pulse generating circuit generates a pulse in synchronization with the rising and falling edges of a clock pulse, and this pulse causes J-
Since KF/F45 is configured to repeatedly set and reset, DSW1, 2 or DSW3,
Even if the number of stitches is set to 00 for any one of 4, it is possible to repeatedly sew only the number of stitches set for the other one, which has the feature that the range of application of sewing work is further expanded.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the schematic configuration of a sewing machine with an automatic tacking device, Fig. 2 is a diagram showing the operation pattern of the sewing machine, Fig. 3 is a diagram also showing the sewing pattern, and Fig. 4 is the present invention. It is a circuit diagram of a control device. In the figure, 101 is a drive machine, that is, an electric motor, 102 is a sewing machine, 106 is a speed control circuit, 107 is a sewing machine operation control circuit, 1 to 4 are thumbwheel switches,
5 to 8 are stitch count counters, RS is a changeover switch, 4
1 to 43 are data flip-flops (D-F/
F), 45 is a master-slave flip-flop (J-KF/F), and 46 is a decoder circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A control circuit for a sewing machine comprising a sewing machine having a tacking function, a driving machine for driving this sewing machine, a speed control circuit for driving this driving machine, and a control circuit for generating circles of different sewing patterns, The sewing machine is equipped with a stitch counting means that is switched according to the different sewing patterns and counts the number of stitches set by the stitch number setting means, and the stitch number counting means is configured to count the number of stitches in the sewing pattern at the start of sewing. 1st to count
and a second stitch counting means for counting the number of stitches of the sewing pattern at the end of sewing, and the first and second stitch counting means are switchable. The first and second stitch number counting means count the number of stitches in response to a clock pulse signal synchronized with the operation of the sewing machine needles, and if the set value of either the first or second stitch number counting means is zero, A control device for a sewing machine, characterized in that sewing is performed by repeating only the set value of the other stitch number counting means.