JPS62394A - Two-needle sewing machine with corner stitch device - 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 [Industrial Application Field] The present invention relates to a two-needle lockstitch machine equipped with a corner stitching device for forming two rows of corner stitches.

[Conventional technology]

As a type of lockstitch sewing machine, a two-needle lockstitch sewing machine is known, which uses two needles to form two rows of parallel stitches.This type of sewing machine generally forms corner stitches. A corner stitching device is attached.

FIG. 4 is a perspective view of a main part of a conventional two-needle lockstitch sewing machine equipped with this type of corner stitching device disclosed in US Pat. No. 2,871,810, and this will be explained based on the figure. A needle bar support shaft 3 is horizontally protruded from the tip of an inverted arm 2 whose base is fixed to the bed 1. The needle bar support 4 extends.

It is supported in a swingable manner by fitting the hole in the base.

Two needle bars 5 and 6 are supported on the needle bar support 4 so as to be movable up and down, and a needle 9 is attached to the lower end of each needle bar 5 and 6 through a needle holder 7 and 8t, respectively. , 10 are attached.

Each needle 9, 10 is equipped with a conventionally known upper thread adjusting device 1.
The upper thread is guided through the thread 1, and the needles 9 and 10 are moved up and down simultaneously while feeding the fabric placed on the slider 12 and pressed by the presser foot 13. Two rows of regular stitches are formed by the upper thread and the lower thread.

A sewing machine whose main parts are configured in this manner is provided with a needle bar switching device for performing corner stitches.

That is, a shaft 14 passing through the upper end of the arm 2 in the front and back directions is rotatably supported on a bearing (not shown) on the arm 2 side. On both outward protrusions, there is a needle bar switching lever 1 formed in a 5-shape.
5, short and small arms 16 are each fixed. On the other hand, a bearing 11 located above the needle bar support 4 and fixed to the upper surface of the arm 2 has a guide stand 18 formed in a T-shape when viewed from above, in a horizontal state and in a horizontal state as shown in the figure. A state where the right side is tilted lower (hereinafter referred to as right tilt).

The guide table 18 and the arm 16 are swingably supported to selectively occupy three positions, including a state in which the left side is tilted downward (hereinafter referred to as "left tilt"). They are connected by a rond 20 having a rotatable rond end 19. At the tip of the needle bar switching lever 15, an fcEs-shaped display plate 2 is fixed to the arm 2 side.
Knob 22 that can be moved along the arcuate edge of 1
is attached to 9, and 1 display board 2111111,
Signed in figure.

Release levers 23 for elastically holding the knob 22 are provided at both end positions of the display screen 21 indicated by R. When the release lever 23 is pressed when the knob 22 is in the position indicated by the symbol 0 or R, the needle bar switching lever 15 is rotated until the knob 22 assumes the neutral position indicated by the symbol 0 in the figure. Reference numerals 3 and 24 shown in FIG. When the knob 22 is in the R position and the guide table 18 is tilted to the right, the switching cam 24 closes the opening on the needle bar 5 side, and the knob 22 is in the R position. When the guide table 18 is tilted to the left, the switching cam 24 moves toward the needle bar 6.
It is configured to close the side opening. Note that when the knob 22 is at the 0 position and the guide table 18 is in a horizontal state, the switching cam 24 does not close any of the openings of the needle bars 5 and 6. The protruding ends 5a, 6a (6a not shown) from the upper end opening of each needle bar 5, 6 are brought into contact with the T-switching cam 24 to stop their vertical movement at the raised position. A clutch device (not shown) is built-in.

The lock stitch and corner stitch operations performed by the conventional sewing machine configured as described above will be explained based on the plan views of the stitches shown in FIGS. 4 and 5. When sewing is started with the knob 22 set to the 0 position and the needle bar switching lever 15 in the neutral state, the switching cam 24 has fully opened the opening for both needles 415.6, so the needle bar 5°6 is The sewing machine moves up and down, and the two-needle lockstitch between A-8 in FIG. 5 is performed. In the following explanation, the state in which the needles 9 and 10 are stuck into the fabric will be referred to as the needles being in the lower position, and the state in which the needles 9 and 10 are at their upper limit will be referred to as being in the upper position. . When the double needle stitching between A and 8 is finished and both needles 9 and 10 are at the lower position of point B, move the knob 22 to the position indicated by the symbol ' and rotate the needle bar switching lever 15. , the guide stand 18 tilts to the right and the switching cam 24 closes the opening on the needle bar 5 side, so that the position B in FIG.
When the needle 9.10 rises to the upper position at the point, the needle 5
The protruding end 5a of the needle 5 comes into contact with the switching cam 24, and only the needle 5 is stopped at the upper position by the action of the clutch device. During this time, the outer needle 6 sews one stitch and then pierces the fabric at point 0 in Figure 5 and is in the lower position, so use the pedal to stop the movement of the needle and move the fabric 90' counterclockwise in Figure 5. After rotating, the movement of the needle is resumed and one stitch is sewn between jDc and 0 using the outer needle 6. Therefore, when the release lever 23 is pressed while the needle 6 is rising at point D, the needle bar switching lever 15I/i knob 2
2 returns to the neutral state where the needle bar 2 occupies the 0 position, the guide table 18 becomes horizontal, and the switching cam 24 opens the openings for the needle bars 5 and 6, so that the clutch device of the rising needle bar 5 is connected. The needle bar 5 returns to the vertically moving state. Therefore, when sewing continues, the double needle stitching between D and E in FIG. 5 is performed.

[Problem that issue 8A attempts to solve] However, in such a conventional two-needle lockstitch sewing machine equipped with a corner stitching device, it is necessary to stop one of the needle bars 5 and 6 when sewing corners. However, this requires a complicated needle bar switching device as described above, which increases the number of parts, increases costs, and causes troublesome and time-consuming operation. Furthermore, the needle 415,
Since the clutch device is provided inside the clutch 6, the cost increases, the structure makes it impossible to rotate at high speed, and there are also problems in terms of durability.

The present invention was made to solve the above-mentioned problems, and has a structure that does not require a complicated needle bar switching device, is simple, inexpensive, and can be operated at high speed. The object of the present invention is to provide a two-needle lockstitch sewing machine with a corner stitching device that can perform all corner stitching functions.

[Means for solving problems]

In order to achieve such an object, in the present invention, the length from the needle hole to the tip of one of the two needles is made shorter than the length from the needle hole to the tip of the other needle. Additionally, a detector is provided to detect the raised position and lowered position of the needle bar when the sewing machine is stopped.

[Effect]

With this configuration, after lock stitching is performed with the twin needles, when the corner stitch is reached and the pedal is moved to the neutral position, only the longer needle sews one stitch and pierces the fabric. The detector detects this at the lower position of the needle and stops the vertical movement of the needle bar, so after rotating the fabric around the needle that has been inserted,
When the pedal is pressed forward, the vertical movement of the needle bar resumes, and the double-needle stitching after corner stitching resumes. After sewing is completed, when the pedal is pushed back, the detector detects the upward position fii of the needle bar and the vertical movement of the needle bar is stopped.

〔Example〕

1 to 3 show an embodiment of a two-needle lockstitch sewing machine with a corner stitching device according to the present invention, FIG. 1 is a perspective view of the main parts thereof, and FIG. FIG. 3 is a perspective view showing the state in which the needle is in the lower position, and FIG. 3 is a plan view of the seam. In the figure, an upper shaft 34 having a flywheel 33 connected to a motor (not shown) at the shaft end is horizontally supported in an inverted arm 32 whose base S is fixed to a ped 31. A crank 35 is fixed to the tip of the upper shaft 34. On the other hand, a crank 3
The other end of the crank rod 31, one end of which is pivotally connected to the eccentric portion of the crankshaft 3T, is fitted so as to be able to move vertically. The fitting end of the guide portion 36a is configured to move up and down. 3"8 is a needle bar supported by a needle bar support 36 so as to be movable up and down, and the crank rod 31
It is connected to the fitting end of the guide portion 36a by a needle bar 39, and is configured to move up and down together with the crank rod 31. Two needles 4 are provided at the lower end of the needle bar 38.
0.41 is attached via the needle holder 42. Among the two needles 40 and 41, one needle 40 is formed to have a shorter length from the needle hole to the tip than the needle of a normal two-needle sewing machine. The needle is longer from the needle hole to the tip than the needle of a normal two-needle sewing machine.

Furthermore, the longer needle 41 is attached to the needle bar 38 so that the needle hole is about 1 to 2 W lower than that of the shorter needle 40. And each needle 40,41.

Upper threads 44 and 45 shown in FIG. 2 are guided through a conventionally known upper thread adjusting device 43 and the like. Reference numeral 46 denotes a presser plate which is lowered by the operation of the presser lever 47 and clamps the cloth between it and the sliding plate 48, and 49 is a presser plate that moves in the same cycle as the vertical movement of the needle 40° and 41 to feed the cloth. It's toothsome. Further, on both sides of the feed tooth 49, there are a pair of hooks 50 and 51 for storing a bobbin for bobbin thread.
is installed. In addition, the left and right hooks 50 and 51 are needle 4.
0°410 In order to accommodate the difference in needle hole position, the timing between the needle and hook is changed to ensure good sewing tension.

9. A pedal (not shown) is provided below the table 31 and can be switched to three stages: forward depression, neutral, and back-up by foot operation. The needles 40 and 41 are moved up and down, etc. for 4 seconds through a detector which will be explained below. 9% detection plate 52 as a detector,
53ra is attached to the end of the upper shaft 34, and one photoelectric detection plate 52 detects the lower position where only the long needle 41 is stuck into the cloth, stops the upper shaft 34, and The other photoelectric detection &53 is configured to detect the running position when the needle 4-υ1, 41 rises to its upper limit and stops the upper shaft 34. One photoelectric detection plate 52 detects only when the pedal is operated to the neutral position, and the other photoelectric detection plate 53 detects only when the pedal is operated repeatedly.

Lockstitching using the sewing machine configured as described above.

Explain the corner stitching operation. The cloth is placed on the slide plate 48, and the presser lever 47 is operated to lower the presser plate 46, so that the cloth is held between the presser plate 46, the slider plate 48, and the feed tooth 49. Then, when you press the pedal forward, the upper shaft 3
4 rotates, both hands 40° and 41 move up and down simultaneously, and the M
Double needle stitching is performed between A-8 in Figure 3. After the longer needle 41 has come out of the fabric at point B in Figure 3, when the pedal is operated to the neutral position, the longer needle 41 will sew one stitch and reach the lower position where it pierces the fabric at point 0 in Figure M3. The photoelectric detection plate 52 detects this, and the upper shaft 34 stops and the needles 41 and 42 stop descending. At this time, since the other needle 40 is short, it has not yet pierced the fabric and no stitches have been formed. FIG. 2 shows the state at this time. When the cloth is rotated counterclockwise 90' with the outer needle 41t in the stopped state, the inner needle 40 is guided to point B of the outer seam sewn earlier. After the cloth has been rotated, when the pedal is depressed forward, the rotation of the upper shaft 34 is restarted, and the double needle stitching between C and D in FIG. 3 is performed.

As described above, the corner seam shown in FIG. 3 is formed.

After sewing is complete, press the pedal to return the needle to 40.
The photoelectric detection plate 53 detects this at the upper position where the needles 40 and 41 have risen to the upper limit, and the needles 40 and 41 stop at the upper limit position, which is convenient for starting the first stitch H.

In addition, in this embodiment, an example was shown in which the outer needle 41 is lengthened and a corner stitch is formed with the point at which it pierces the fabric as the lower position, but since the shape of the corner stitch differs depending on the gauge width and the feed amount. , with the rotational fulcrum of the fabric on the inside, long needle 4
Corner stitching may be performed with the position where 1 is about to come out of the cloth as the lower position.

Furthermore, although this embodiment shows an example in which the left and right pots so and si are of the same height, the thickness of the rope product is thick.

If it is necessary to further increase the step of the needle 40, 41, and the limit of the needle hole step and needle tip step is exceeded,
A difference may be provided between the heights of the hooks 50 and 51, and a thread guide may be provided on the arm 32 to adjust the thread take-up amount to change the left and right thread take-up strokes to improve the sewing tension and simplify the process. Corner stitching may also be possible.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a two-needle lockstitch sewing machine with a corner stitching device, the length from the needle hole to the tip of the two needles is equal to that of the other needle. The length is shorter than the length from the needle hole to the tip, and
By installing a detector that detects the raised and lowered positions of the needle bar when the sewing machine is stopped, there is no need to provide a complicated needle bar switching device like in the past, and only detection can be done by pedal operation and a detector. Since lock stitches and corner stitches can be easily performed using two needles, the structure is simple, the number of parts is reduced, and manufacturing costs are reduced. Operation is also simplified and work efficiency is improved. . Also.

Since a clutch device is not provided inside the needle bar unlike in the past, high-speed operation is possible) and durability is improved.

[Brief explanation of drawings]

1 to 3 show an embodiment of a two-needle lockstitch sewing machine with a corner stitching device according to the present invention, FIG. 1 is a perspective view of the main parts thereof, and FIG. FIG. 3 is a perspective view showing the state in which the needle is in the lower position, FIG. 3 is a plan view of the seam, FIG. be. 38...Needle bar, 40.41...Needle, 52゜53
...Photoelectric detection plate.

Claims (1)

[Claims] The length from the needle hole to the tip of one of the two needles is shorter than the length from the needle hole to the tip of the other needle, and these two needles are combined into one needle bar. 2 pieces with a corner stitching device, characterized in that they are attached to the machine and move up and down integrally, and are equipped with a detector whose detection position can be adjusted to detect the raised and lowered positions of the needle bar when the sewing machine is stopped. Needle lockstitch sewing machine.