JPS63272392A - Bobbin thread holding and regulating apparatus of sewing machine - 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] This invention is a bobbin thread holding and adjusting device for a sewing machine, which is particularly suitable for forming the next stitch after thread trimming in a sewing machine, and which holds the bobbin thread with one pinch pressure. Moreover, the present invention relates to a bobbin thread clamping device for a one-piece sewing machine, which allows the clamping pressure to be adjusted appropriately.

[Conventional technology]

Conventionally, as shown in Japanese Utility Model Application Publication No. 60-148580, a thread cutting blade for cutting the upper thread and lower thread is provided with a
In addition to providing a bobbin thread holding plate that holds the bobbin thread of the cut thread,
A thread cutting device for a T-comms sewing machine is generally known, which is provided with an adjusting means that can adjust the bobbin thread clamping force of the bobbin thread holding plate. In this conventional sewing machine thread trimming device, the tip of the bobbin thread holding plate that clamps the bobbin thread comes into contact with a brush or the like when assembling the sewing machine or cleaning the hook, causing liquid to form. However, there is a problem in that the pressure used to clamp the bobbin thread becomes unstable.

In addition, since the adjusting means is located at a distance from the tip η) of the bobbin thread holding plate, even if the adjusting means is operated, the pressure is evenly transmitted to the bobbin thread. There is a problem that sufficient lζ cannot be obtained.

Furthermore, since the adjusting means does not have a mechanism for adjusting the adjustment state, the adjustment state may fluctuate due to vibrations of the sewing machine, etc., and the bobbin thread clamping force exerted on the bobbin thread holding plate may change. There is also the issue of getting older. In particular, the bobbin thread clamping force is 10 to 20 g.
This tendency is remarkable at low tensilons.

(6) In order to solve the problem of force), Applicant +, in Application No. 1986, proposes that the bobbin thread can be stably held, and (6) the bobbin thread clamping force can be adjusted by an adjustment mechanism. We proposed a thread cutting device for sewing machines that can stabilize the sewing machine.1
child. In this patent application No. 1983,
The thread cutting blade, which can reciprocate near the hook that forms the lockstitch stitch in cooperation with the needle moving up and down, moves from the needle's bottom dead center to the needle's top dead center. During the thread trimming cycle, the thread trimming blade moves forward from the bobbin force inside the hook to the position where it captures the bobbin thread leading to the stitched part of the fabric, and the thread trimming blade captures the bobbin thread using the V-shaped hook and returns to its original position. When moving back to the bobbin, the bobbin thread is pulled out by the required length (bobbin force) and cut by the fixed blade.The cut end of the bobbin thread is cut between the thread cutting blade and the bobbin thread holding plate. It is elastically clamped and held. By adjusting the threading of the adjustment screw of the adjustment mechanism, this holding force directly suppresses the back surface Eζ of the bobbin thread holding plate in relation to the threading of this adjustment screw. The compression force of the coil spring is adjusted by changing the amount of compression of the coil spring, and then the adjustment screw is fixed in place so that it does not loosen and shift.

[Problems solved and resolved by the invention] Since the thread trimming device is constructed as described above, when adjusting the bobbin thread holding force, it is necessary to turn the adjusting screw with a screwdriver, When fixing this adjustment state without being affected by vibrations of the sewing machine, etc.,
You have to hold the adjustment screw in one hand and use a screwdriver 17 to fix it, and then use the other hand to tighten the bolt with a wrench, which is a hassle. This adjusting screw, locking element, and lid are made of thin leaf springs and are located on the back side of the bobbin thread holding plate. This has to be placed in a small space, so when rotating and fixing the lock element/lid with a wrench, use the two sides of the wrench to
It is difficult to match the width of the face, and the rotation stroke of the wrench is sufficient. There is one drawback, such as the work of combining the widths across two sides and rotating a small amount over and over again to fix them. During this repeated work, the wrench held in one hand hits a thin leaf spring, deforms it, and loses its holding function, and the wrench hits the hook, feed dog, etc. and damages them, causing thread slippage. There is one drawback, such as deterioration and loss of sewing function. When assembling the sewing machine or adjusting the gap between the needle and the hook, install the hook and thread trimming device in a position that is different from the mounting base. There was one case where I had to reposition the coil because the spring and bobbin thread holding plate were misaligned.

This invention has been made to solve the above-mentioned problems, and it is possible to easily and quickly adjust and fix the adjusting screw with a single screwdriver using only one hand without the need for both hands. The purpose is to eliminate skipped stitches at the beginning of sewing even if a bobbin thread made of the same material is used. Sarado ζ has a lower thread adjustment mechanism integrated into the mounting base on which the hook and thread trimming device are attached.
The purpose is to make it possible to assemble and adjust it at the same time.

[First Means to Solve the Problems] The bobbin thread holding and adjusting device of the sewing machine according to the present invention has a sewing machine base J fixed to a mounting base, a fixed blade T fixed blade, a needle thread connected to a needle, A single thread cutting blade is supported on a mounting base so as to be reciprocatable along the lower surface of the fixed blade between the lower surface of the throat plate and the shuttle so as to capture the bobbin thread and cut the two threads in cooperation with the fixed blade. , the base is fixed to the mounting base so that the tip is always in contact with the lower surface Eζ of the thread trimming blade, and a bobbin thread holder is fixed to the mounting base, and an adjustment screw support plate is provided to fix the base to the mounting base. An adjustment screw supporting a coil spring facing a bobbin thread holder is supported at the tip of the adjustment screw support plate so as to be able to expand in a spiral manner, and a cut portion that intersects with the adjustment screw and a screw orthogonal to the cut portion. The screw has a Cζ which fixes and holds the adjusting screw through the cut portion.

[Effect]

The bobbin thread holding and adjusting device of the present invention is suitable for forming the next stitch after thread trimming, and the clamping pressure of the bobbin thread can be easily adjusted with one hand using a screwdriver, and the adjustment state can be adjusted easily. Since it can be maintained continuously without shifting due to vibrations, etc., there is no risk of the bobbin thread coming off and skipping stitches, and it is possible to form stitches that are both beautiful and strong.

[Embodiments of the invention]

Figures 1 to 6 show one embodiment of this invention (1
) is located below the throat plate (not shown), and is a one-piece hook that rotates in a horizontal plane and cooperates with a known needle to form lockstitch stitches, and includes an outer hook (2) that captures the needle thread. , this outer pot (2)
It is supported by a circle 6ζ and has an inner hook (3) for storing a bobbin (not shown) for the bobbin thread (4) inside.

(5) is a mounting base that attaches the hook 1) and the thread trimming device (described later) to the sewing machine bed using screws, etc.; (6) is a moving body that reciprocates and attaches the thread trimmer (7); It is slidably fitted into the mounting base (5). (8) is the thread cutting blade (7)
) is formed with a thread catching flick part (9) and a cutting blade QO, and αυ is a thread cutting part (7).
The lower thread (4) is fixedly disposed near the thread cutter and works in cooperation with the thread cutter blade (7) to catch the bobbin thread (4) and cut the bobbin thread (4). (c) is the bobbin thread holding plate, and the thread cutting blade (7)
The lower thread (4) after thread cutting is placed below the lower thread contact area α.
3 and the thread cutting blade (7). Q4)
is screwed to the mounting base (5) with a single adjustment mechanism that adjusts the bobbin thread holding force by the bobbin thread contact portion 0, and is screwed to the inverted-shaped adjustment screw supporting plate (A). Adjustment screw Q9 and
To fix the adjustment state of the adjustment screw Q9, the adjustment screw support plate (end) is provided with a cutout aQ from the tip end, and holes aη and A threaded part (T) is provided, and when the screw @ is tightened, the cut part contracts and fixes the adjustment screw 01, and the bobbin thread contact part that gets stuck in the operation of the adjustment screw Q9 is The coil spring ■υ that adjusts the spring pressure is installed by loosely fitting the tip of the rod of the adjustment screw 01, so as to prevent the coil spring ■υ from tilting and pressing the bobbin thread holding plate @ and from falling and detaching. It is attached.

(A) is a female stand on which the fixed blade (6) is attached, and it is attached to the mounting base (5) so as to be adjustable in the vertical direction, and is engaged with the blade part of the thread cutting blade (7) so that the thread can be cut. You can get -1. The rod is rotatably supported on the mounting base (5), has a roller (c) at its tip, and fits into the groove (c) of the moving body (6). .

Next, we will explain the operation of the above device. At the end of sewing, when the operator operates a pedal (not shown), during the thread trimming cycle,
The swinging arm @ swings, and as a result, the movable body (6) advances on the horizontal plane via the roll ram, and is attached to the movable body (6).
The thread cutting blade (7) moves forward. At this time, the thread cutting blade (7
), the needle rises from near the bottom dead center and reaches the hook thread retrieval section (2).
) captures the needle thread @ and transfers it immediately after the first thread! ! jf! L beginning,
Insert the thread cutting part (8) into the needle thread loop, and separate the needle thread @ left on the needle side, the needle thread C27' left on the fabric length side, and (ζ sorting,
Furthermore, the thread cutting blade (7) passes under the bobbin thread (4) and moves forward. Furthermore, as the sewing machine rotates simultaneously between thread trimming cycles, the thread trimming blade (7) moves forward this time, and the beginning and sorting 1st needle thread (27) and bobbin thread (4) catch the thread of the thread trimming blade (7). It is captured by the flywheel section (9). Then, when it moves further forward, the two threads are cut to an appropriate length just before the return movement is completed due to the cooperation with the fixed blade α sword, and the cut end of the bobbin thread (4) after cutting is cut by the thread cutting blade. (7) and the lower thread contact portion 0 of the lower thread holding plate @.

Is this holding force a coil spring? Is the compression of υ simply due to a proportional compressive force?
The amount of compression of rJ is adjusted by the threaded joint of adjustment screw ag. To explain this adjustment work in detail, first, by loosening the screw (to), /+I section screw support plate α9 cut IJJ'
) section αQ is loosened and the adjustment screw Q9 can be adjusted in a spiral manner, adjust the adjustment screw Q9 in a spiral manner, adjust the compression amount of the coil spring Q1) to the required holding force, and then tighten the screw. When (A) is tightened, the cut portion αG contracts, and when the adjustment screw Q9 is tightened, its screw movement is fixed.

〔Effect of the invention〕

As explained above, the bobbin thread holding and adjusting device for a sewing machine according to the present invention is such that the clamping pressure of the bobbin thread holder can be freely adjusted using the adjustment screw. By adjusting the force, the clamping pressure of one bobbin thread suitable for forming the next ω stitch after thread cutting can be easily adjusted with one hand T and one screwdriver Cζ, and the adjustment state can be adjusted by vibration, etc. Because it can be maintained continuously without slipping, there is no risk of the bobbin thread coming off and skipping, making it beautiful and strong.
ζIt has the effect of forming reliable seams.

Since the -knot screw support plate is integrally attached to the mounting base lr, it is possible to adjust the hook and thread trimming device as a unit before assembling it to the sewing machine body. When adjusting the clearance between the hook and the hook, there is no possibility that the bobbin thread holding plate and the coil spring will be misaligned.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a bobbin thread holding device according to an embodiment of the present invention, Fig. 2 is a plan view thereof, and Fig. 8 is a thread cutting blade 1.
Surface fixed blade, main part plan view of the pot, the fourth factor is IV-F/ of m1 diagram
FIG. 5 is a cross-sectional view of a main part taken along the line V-V in FIG. 1, and FIG. 6 is a perspective view of a main part. (1) is the hook, (2) is the outer hook, (3) is the inner hook, (4) is the bobbin thread, (5) is the mounting base, (6) is the movable body, (
July J thread cutting blade, (8) is thread handling part, (9) is F,・
・Ri part, αQ is the cutting blade, αη is the fixed blade, (2) is the bobbin thread holding plate, U is the thread contact part, α is the adjustment mechanism, (to) is the adjustment screw support plate, αG is the cutting part, α is the hole, (to) is the female thread, αG is the one-section thread, the handle is the tip of the rod, Q'D is the coil spring, (a) is the female stand, (c) is the swinging arm, (to) is a roller, (a) is a groove, and (to) is a screw. In addition, in the figures, the same reference numerals are the same or corresponding parts are indicated by 5,

Claims (1)

[Claims] A fixed blade supported on a mounting base fixed to the sewing machine bed below the throat plate, and a fixed blade that catches the needle thread and bobbin thread connected to the needle and works together with the fixed blade to cut the needle thread and bobbin thread. The thread cutting blade is supported on a mounting base so that it can reciprocate along the bottom surface of the fixed blade between the bottom surface of the plate and the hook, and the base is fixed to the mounting base so that the tip is always in contact with the bottom surface of the thread cutting blade. The bobbin thread holder has a base fixedly supported on a mounting base, and has an adjustment screw at its tip that supports a coil spring facing the bobbin thread holder, and a cutout that intersects with the adjustment screw, and a cutout that intersects with the adjustment screw. and an adjustment screw support plate having a screw orthogonal to the cut portion to enable adjustment of the screwing position of the adjusting screw, and fixing the screwing position of the adjusting screw with a screw orthogonal to the cut portion. Lower thread retention adjustment device for sewing machines.