JP3324812B2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine,
The present invention relates to a sewing machine that can automatically form a lock stitch before forming a selected pattern.

[0002]

2. Description of the Related Art Conventionally, a sewing machine of this type is provided with a stitch designation switch for designating a stitch in order to combine the stitches before forming a selected pattern, and operating the stitch designation switch. When the stop stitching mode is selected, the stop stitch is formed by combining the stitches before forming the selected pattern. Also, in the sewing mode, when the sewing machine is temporarily stopped during the formation of the pattern after the formation of the fixing stitch, and the sewing machine is restarted after the presser foot is raised, a new pattern is formed. It is configured to form a pattern after determining and forming a stop stitch.

[0003]

However, in the conventional sewing machine, since the sewing is formed in the sewing mode after the presser foot is raised, the sewing is formed before the pattern is formed. For example, when the sewing machine is temporarily stopped to rotate the work cloth during the formation of the pattern and the work clamp foot is raised, the sewing is not performed when the sewing machine is restarted. There is a problem that the formation of the pattern is started after a while. Therefore, in this case, when the stop sewing is not necessary for restarting the sewing machine, a complicated operation of releasing the stop sewing mode has been performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. In the stop sewing mode, when the stop sewing is not required when the sewing machine is restarted after the work clamp foot is raised, the stop sewing is formed. An object of the present invention is to provide a sewing machine capable of forming a pattern without performing the above.

[0005]

In order to achieve the above object, a sewing machine according to the present invention comprises a fixing stitching designating means for designating a fixing stitch mode for forming a combination of fixing stitches before forming a pattern, and a sewing needle. Presser foot detecting means for detecting whether or not the work clamp foot is raised while the vertical movement of the sewing machine is stopped; needle position detecting means for detecting whether the stop position of the sewing needle is below the needle plate; When the stop sewing mode is designated by the means, the presser foot detecting means detects that the presser foot is raised, and the needle position detecting means determines that the sewing needle stop position is below the needle plate. when it is detected
Is provided with control means for controlling the formation of the lock stitches before the formation of the pattern when the sewing machine is restarted .

[0006]

In the sewing machine according to the present invention having the above-described configuration, when the fixing sewing mode is designated by the fixing sewing designation means, when the presser foot detecting means detects that the presser foot is raised, The needle position detecting means detects whether or not the stop position of the sewing needle is below the needle plate. When the control means detects that the stop position of the sewing needle is below the needle plate , the sewing machine is reset. At the time of starting , control is performed so that the formation of the lock stitches before the formation of the pattern is prohibited.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

First, the electrical configuration of the sewing machine will be described with reference to FIG. Note that the external configuration of the sewing machine is the same as that of a general sewing machine, and a description thereof will be omitted.

A start / stop switch (hereinafter abbreviated as S / S switch) 10 for starting and stopping the sewing machine is configured to supply a signal corresponding to the operation to the CPU 12. Presser switch 14
Is configured to supply a presser lifting signal to the CPU 12 when the known work clamp foot is raised. And
The stitching designation switch 16 is configured to supply a stitching designation signal to the CPU 12 in accordance with the operation. The needle position detector 18 is configured to detect a vertical position of a known sewing needle with respect to a known needle plate, and to supply a needle position signal corresponding to the detected position to the CPU 12. The pattern selection device 20 is configured to select a desired pattern from a plurality of patterns and to supply a pattern selection signal to the CPU 12. The ROM 22 is configured to store pattern data and fixing sewing data relating to a pattern that can be selected by the pattern selection device 20. CPU 12
Are configured to operate in accordance with flowcharts described later in accordance with various signals supplied.

The main motor drive circuit 24 includes a CPU 12
Is configured to operate the main motor 26 based on a command from The rotation of the main motor 26 drives the sewing needle and the known shuttle to form stitches on the work cloth. The Z pulse motor drive circuit 28 is configured to operate the Z pulse motor 30 based on a command from the CPU 12. And Z
The sewing needle is configured to swing left and right by the rotation of the pulse motor 30. F pulse motor drive circuit 32
Is an F pulse motor 3 based on a command from the CPU 12.
4 is configured to operate. The work cloth is fed back and forth by the rotation of the F pulse motor 34. The lock stitch LED 36 is illuminated when the lock stitch is designated by the lock stitch designation switch 16, and informs the operator that the lock stitch will be formed before the pattern is formed.

Next, the operation of the sewing machine configured as described above will be described with reference to the flowcharts of FIGS.

First, when power is supplied to the sewing machine, the CPU
In step SP1, an initial setting is performed in step SP1 (hereinafter referred to as SP1). The initial settings are as follows.
Origin setting and automatic selection of straight line patterns are included.

Next, the fact that a new pattern has been selected is indicated in SP.
When the determination is made in step 2, the CPU 12 sets the selected pattern in SP3. Then, the lock stitching designation switch 16 is operated, and the CPU 12
If it is determined in P4 that the lock stitch before the formation of the pattern is designated, in the step SP5, the lock stitch mode is set, and the lock stitch LED 36 is turned on. The CPU 12
In SP4, when it is determined that the stitch before forming the pattern is not specified, in SP6, the normal mode is set, and the stitch LED 36 is turned off.

In the stop sewing mode, when the S / S switch 10 is operated, the CPU 12 determines in step SP7 that the S / S switch 10 has been operated, and in step SP8, the CPU 12 After the Z-pulse motor 30 and the F-pulse motor 34 are driven to form the stitches, the selected pattern is formed in SP9.

In the normal mode, when the S / S switch 10 is operated, the CPU 12 determines in the SP 10 that the S / S switch 10 is operated, and
In SP9, the main motor 26 and the Z pulse motor 3
The 0 and F pulse motors 34 are driven to form the selected pattern.

When the S / S switch 10 is operated again, the CPU 12 determines that the S / S switch 10 has been operated in SP11, and stops the sewing machine in SP12.

Next, referring to FIG. 3, while the sewing machine is stopped in the stop stitching mode, the operator is required to replace the work cloth or to change the sewing position. A case where a pattern is formed after raising the presser foot in a state where the work presser is not stabbed will be described. In this case, the sewing thread is often cut when the work cloth is replaced or the sewing position is changed.

First, the CPU 12 in SP13
It is determined that the sewing mode is the stop sewing mode. In SP14, it is determined that the presser foot is raised by the presser switch 14, and in SP15, the needle position detector 18 is in the needle up state while the presser foot is being raised. Is determined.

Then, in SP16, the CPU 12 sets a stop sewing start flag, and thereafter, the S / S
When the S switch 10 is operated, the CPU 12
7, it is determined that the S / S switch 10 has been operated, and in SP18, it is determined that the stop sewing start flag has been set, and in SP19,
Perform the lock stitch start. This stop sewing start,
Since the operations of SP8 and SP9 described above are performed, the description thereof will be omitted.

Next, while the sewing machine is stopped in the stop sewing mode, the operator raises the work clamp foot in the needle-down state (the state where the sewing needle is stuck in the work cloth), and then rotates the work cloth. The case where the cloth presser foot is lowered again to form a pattern continuously without cutting the sewing thread will be described. In this case, the sewing machine temporarily stops, but since the pattern is formed continuously, it is not necessary to form a lock stitch when the sewing machine is restarted.

First, the CPU 12 in SP13
It is determined that the sewing mode is the stop sewing mode. In SP14, it is determined that the presser foot has been raised by the presser switch 14. In SP15, the needle position detector 18 indicates that the needle is in the lower state while the presser foot is being raised. Is determined.
Then, in SP20, the CPU 12 resets the stop sewing start flag, and thereafter, executes the S / S switch 1
When 0 is operated, the CPU 12 returns to SP17
When it is determined that the S / S switch 10 has been operated, SP
At 18, it is determined that the stop sewing start flag has been reset, and at SP21, a normal start is performed. Since this normal start performs the above-described operation of SP9 without forming the stitches, the description thereof is omitted.

If it is determined in SP13 that the sewing mode is not the sewing mode, and if the presser foot is not raised in SP14, the CPU 12 resets the sewing start flag in SP20 and performs sewing. The pattern is formed without any problems.

[0023]

As is apparent from the above description, the sewing machine according to the present invention is capable of forming a lock stitch when the sewing machine is restarted after the work clamp foot is raised in the lock stitch mode and the sewing machine is not required. The pattern can be formed without performing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electrical configuration of a sewing machine according to an embodiment of the present invention.

FIG. 2 is a first half of a flowchart showing the operation of the sewing machine.

FIG. 3 is a second half of a flowchart showing the operation of the sewing machine.

[Explanation of symbols]

 12 CPU 14 Work clamp switch 16 Stop sewing designation switch 18 Needle position detector

Claims (1)

(57) [Claims] 1. A fixing stitching designating means for designating a fixing stitch mode for forming a combination of fixing stitches before forming a pattern, and determining whether or not a presser foot has been raised during stopping of vertical movement of a sewing needle. Presser foot detecting means for detecting, a needle position detecting means for detecting whether or not the stop position of the sewing needle is below the needle plate, and a presser foot when the fixing stitch mode is designated by the fixing stitching designating means. When the detecting means detects that the presser foot is raised and the needle position detecting means detects that the stop position of the sewing needle is below the needle plate , the pattern is not formed when the sewing machine is restarted. And a control means for controlling so as to prohibit the formation of the lock stitches.