JPS5923833B2 - Full-rotation sewing machine balance mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new thread take-up mechanism for a full-rotary sewing machine, and particularly to a thread take-up mechanism that provides a large slack to the needle thread without unnecessarily lengthening the needle thread pull-up lever and allows the needle thread to pass through the suturing device. To provide a thread take-up mechanism for a new full-rotary sewing machine that can quickly restore the suturing device to its original tension state after it has been pulled out, thereby making it possible to increase the size of the suturing device.

Recent full-rotation type D sewing machines, especially industrial sewing machines, tend to rotate at increasingly higher speeds.

However, since the bobbin used to wind the bobbin thread has a diameter of about 20 mm and a winding length of about 30 m, it is possible to wind the bobbin thread in an extremely short time. is used up.

Therefore, the troublesome work of removing the bobbin case from the inner hook, replacing the bobbin, and reinstalling the bobbin case into the inner hook must be frequently performed, which is difficult for professional workers who consume a large amount of the same bobbin thread. The effort and time required to replenish the bobbin thread are immeasurably large.

Therefore, attempts have been made to increase the amount of winding of the bobbin thread around the bobbin by increasing the size of the suturing device including the bobbin and the bobbin case, but the following problems arose when attempting to increase the size of the suturing device.

That is, when increasing the size of the suturing device, the slack required for the needle thread to pass through the suturing device must be increased accordingly, and once the needle thread has passed through the suturing device, it must be quickly returned to its original tension state. Must be.

The only way to accomplish this using a conventional scale system using a single needle thread pull-up lever is to increase the effective stroke of the needle thread pull-up lever by increasing its length.

However, by doing this, the needle thread pull-up lever extends largely in the direction of the user of the sewing machine, and there is a risk that the lever will hit the user, which is impractical.

As described above, the necessity of increasing the length of the needle thread pull-up lever has been one of the major obstacles to increasing the size of the force suturing device.

Therefore, the present invention makes it possible to give a large slack to the needle thread without unnecessarily lengthening the needle thread pull-up lever, and to quickly return the needle thread to its original tension state after passing through the suturing device. , which attempts to provide a new scale mechanism for a full-rotation sewing machine that makes it possible to increase the size of the suturing device.A balance weight is fixed to the tip of the arm shaft, and the scale mechanism is mounted at an eccentric position of the balance weight. A pin for operating and driving the needle bar is fixed, and one end of two needle thread pull-up levers of the same shape and size are rotatably supported on the pin so as to face in opposite directions, and the two needles are The thread pull-up lever is rotatably supported on sewing machine component members at equal intervals in opposite directions from a vertical line passing through the center of the arm axis, at equal intervals from the pins that support the thread pull-up lever. The anchor link is characterized in that the ends of the anchor links are connected to each other.

The details of the present invention will be explained below according to specific embodiments shown in the accompanying drawings.

Figures 1 and 2 show the balance mechanism 1 of the full-rotation type sewing machine of the present invention.
2 is a bracket arm, and the vicinity of the tip is shown in the figure.

3 designates an arm axis, which is longitudinally supported within the bracket arm 2 by a bearing 4 in the distal end of the bracket arm 2 and a similar bearing (not shown) at the proximal end of the bracket arm 2. , is configured to be rotated by a suitable drive mechanism.

The arm shaft 3 has a cantilever-like portion extending from the bearing 4 at the tip of the bracket arm 2, and a counterweight 5 is fixed adjacent to the bearing.

At the eccentric position of this balance weight 5, there is a needle bar 1 which also serves as a lever for operating the balance mechanism.
A driving pin 6 is fixed.

One ends of two needle thread pull-up levers 1, 1 of the same shape and size are rotatably supported by the pin 6 so as to face in opposite directions, and these two needle thread pull-up levers 1. Thread holes 8, 8 are bored at the tips of the γ, respectively.

Then, the pin 6 of each of the two needle thread pull-up levers is
Intermediate pins 9, 9 are fixed to the bracket arm 2 at equal distances from each other in opposite directions from a vertical line passing through the center of the arm shaft 3. The distal end of the anchor link 11.11 is rotatably connected to the supporting shaft IL), 10.

Incidentally, a needle bar driving link 12 is fixed to the pin 6 fixed to the balance weight 5 together with the needle thread pull-up lever γ, 1, and the tip of the link link 12 is swingably connected to the needle bar 13. The needle bar drive link 14 is rotatably connected to the tip of the needle bar drive link 14.

In addition, 15 is a needle attached to the tip of the needle bar 13, and 16 is a thread tension device.The thread tension device 16 is provided on the upper surface of the bracket arm 2.

Further, 17 is a presser foot. The needle thread pull-up levers 1 and 7 rotate in opposite directions while moving horizontally and vertically, that is, they rotate to open and close the fan, so that the needle thread 18 taken out from the thread tension device 16 is thread-guided. After passing through the thread holes 8, 8 of the two needle thread pull-up levers γ and 1 (not shown), the thread heads directly or through a suitable thread guide (not shown) to the needle 15 into which the thread has been inserted.

According to this balance mechanism 1, there are two needle thread pull-up levers, which are always rotated in opposite directions around the same center. Compared to the thread take-up mechanism, it is possible to give a relatively large slack to the needle thread 18 without unnecessarily lengthening the length of the needle thread pull-up lever γ, 7. It is possible to quickly return to the original state of tension.

Therefore, this scale mechanism 1 is most suitable for use in combination with a suturing device in which the winding amount of the bobbin thread is increased by increasing the size.

Therefore, a suturing device that is larger in size and has a larger winding amount of the bobbin thread will be described below.

3 to 6 show an example 19 of a large-sized suturing device, in which the suturing device 19 is fixed to an inner hook 20, a larger hook 21, and the larger hook 21, and the inner hook 20 is moved in cooperation with the larger hook 21. An inner hook holding lid 22 and a bobbin 23 for holding the inner hook rotatably
and a bobbin case 24, and the inner diameter of the inner hook 20 (approximately equal to the outer diameter of the bobbin) is about three times that of the inner hook of a conventional suturing device, and the inner diameter of the inner hook 20 is approximately three times larger than that of the inner hook of a conventional suturing device. However, the rotation of the large pot 21 with respect to the inner pot 20 is smoothly performed as will be described later.

The inner pot 20 is formed into a pot shape, and the side wall 25 of the inner pot 20
An outer circumferential bearing rib 26 is provided on the outer surface of the side wall 25 at a position slightly inward from the opening end thereof, and a portion extending from the outer circumferential bearing rib 26 of the side wall 25 to the rear wall 27 is provided with an outer circumferential bearing rib 26.
Tapered slide that becomes thinner as it goes in the direction 2
It is said to be 8.

The outer peripheral support rib 26 is not provided on the entire circumference of the side wall 25 of the inner pot 20, but is provided at the top portion of the inner pot 20, that is, at a location corresponding to a portion where a drop-off hole 29, etc., which will be described later, is formed. One end, that is, the end on the side opposite to the rotating direction of the large hook 21 and the inner hook holding lid 22, which will be described later, is a hook portion 30 that guides the upper thread 18 to the rear of the inner hook 20. As is clear from the figure, the end face is formed so as to face diagonally rearward, and the support rib 26 is formed diagonally so that the wall thickness of the support rib 26 becomes thinner toward the side wall 25 of the inner pot 20.

Further, a groove 31 is formed over the entire outer circumferential support rib 26, and a large number of small holes 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32 are formed in the outer peripheral supporting rib 26 at regular intervals in the circumferential direction on both side walls forming the groove 31. ...
... is drilled, and pins 33, 33 ... are drilled in the opposing small holes.
. . are fixed, and the pins 33, 33, . is rotatably fitted.

Note that the small rollers 34, 34 provided on this support rib 26
．． . . . is in contact with the inner surface of an inner pot holding lid 22 fixed to a large pot 21, which will be described later, and the large pot 21 is connected to the inner pot 20.
Since the purpose is to ensure smooth rotation of the inner hook holding lid 22, a means as shown in FIG. 4 may be used instead of the above-mentioned means.

That is, the supporting rib 26 has a large number of holes 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35. ......, and the hole 35
is formed to be able to rotatably hold the small ball 36, and is formed so that a portion of the small ball 36 protrudes from the outer surface and both side surfaces of the supporting rib 26, and the hole 35 formed in this way
After the small ball 36 is inserted into the hole 35, the small ball 36 is prevented from coming off from the hole 35 by, for example, extending a stopper over the insertion opening of the hole.

Reference numeral 37 denotes a spiral thread count guide for making it easier for the upper thread to slide through the hook 28 of the inner hook 20 and pass through the back of the inner hook. They are formed as protrusions on the inner hook sliding surfaces 28 at positions separated from each other in the rotational direction of the inner hook 21.

Reference numeral 38 is a flange, and the flange 38 is formed approximately on the right half in FIG. A notch 39 is formed into which a tongue of a finger (not shown) for preventing rotation of the inner hook is received.

Further, 40 is a guide groove for the lower thread 41.

42 is a pin for mounting the bobbin case 24 which is provided upright at the center of the inner surface of the rear wall 27 of the inner hook 20; 43 and 43 are engagement recesses for engaging the engagement pieces of the bobbin case 24; and 44 are the bobbin case 24 This is a fitting groove into which the lower thread guide is fitted.

The large pot 21 is formed into a cup shape like the inner pot 20.
The inner surface of the side wall 45 is formed to have a diameter smaller than the outer diameter of the outer peripheral support rib 26 formed on the inner hook 20 and slightly larger than the sliding surface 28.

The side wall 45 of the cauldron 21 is provided with a notch 46, and the rear wall 4γ is provided with a plurality of approximately fan-shaped notches 48 around the lower shaft fixing portion provided in the center to reduce weight. There are several.

In addition, 49 is a notch for preventing the needle thread from digging between the front end surface of the hook 21 and the rear surface of the outer peripheral support rib 26;
0°50, . . . are screw holes for fixing the cauldron 21 which will be described later, 51.5L . . . are screws for fixing the cauldron to the lower shaft 52, and 53 are holes drilled into the lower shaft 52. This is a lubricating oil outflow hole that communicates with the provided lubricating oil supply hole 54, and the outflow hole 53
The lubricating oil that comes out passes through the groove 55 and reaches the support rib 2 of the inner hook 20.
Oil is added around 6.

The inner pot holding lid 22 is formed by cutting a portion with a certain width to form a gap 56, so that it has a substantially ring shape, although it is not perfect. A protrusion 57 is formed on the inner surface.

The presser lid 22 has an inner diameter approximately equal to the outer diameter of the large pot 21, and the protrusion 5γ is formed on the inner pot 20 to such an extent that it does not touch the outer surface of the inner pot 20 near the open end. The support rib 26 is formed so as to come into contact with the front and rear surfaces of the bearing rib 26.

At one end of the gap 56 of the presser cover 22, a sword-shaped needle thread scooping part 58 is formed that projects in the direction of the gap, and an elastic needle thread presser piece 59 overlaps on the needle thread scooping part 58. A clamping part 60 that loosely sandwiches the needle thread 18 between the needle thread scooping part 58 and the needle thread pressing piece 59 is formed as shown in FIG.
is formed.

The gap 56 at the front end of the inner pot holding lid 22 is approximately 1
At a distance of 80°, a needle thread slit portion 61 is formed so that the amount of forward protrusion gradually increases as it goes in the direction opposite to the direction of rotation.

Since it is difficult to fix the inner pot holding lid 22 to the large pot 21 while it is in a ring shape, it is formed to be divided into halves as shown in the illustrated embodiment.

Furthermore, 62,62. . . . screw holes 63, 63. formed in the cauldron 21. This is a screw insertion hole drilled at a location that matches .

The bobbin case 24, like a conventional bobbin case, has a disc shape without a so-called bobbin storage chamber, and includes a disc-shaped case main body 64 and a bobbin insertion insert provided upright in the center of the case main body 64. It consists of a locking mechanism 66 for detachably attaching the shaft 65 and the case body 64 to the inner hook 20, and a guide means 6γ for preventing the bobbin thread 41 from being drawn out more than necessary from the bobbin 23.

The bobbin insertion shaft 65 is formed in a cylindrical shape so that it can be externally fitted onto the pin 42 provided upright in the inner hook 20, and its length is determined by attaching the bobbin case 24 to the inner hook 20 using a locking mechanism 66 which will be described later. (The tip is formed so that it touches the inner surface of the rear wall 27 of the inner pot 20 or is slightly separated from the inner surface of the rear wall 27 of the inner pot 20.

The locking mechanism 66 slides while being guided by a square hole 68 with a substantially rectangular cross section formed to cross the center of the disc-shaped case body 64, and has two locking pieces 69 at the outer ends. Sliding pieces γ0, 70, the two sliding pieces 70, 70, coil springs 71, 71 that bias the two sliding pieces 70, 70 toward the center of the disc-shaped case body 64; Connect the two sliding pieces 70, 70 to the coil sprocket IJ 7g1
It consists of a suppressing piece γ2 for sliding in the radial direction of the disc-shaped case body 640 against an angle of 1° γ1.

Two sliding pieces10. A protruding piece 13 that protrudes upward or downward is formed at the central end of the upper or lower disc-shaped case body 64 in FIG. The pieces 73 are loosely fitted into spring receiving holes 74 and 74 formed in the square hole 68, respectively, and the coil spring 7L71 is compressed therein.

The coil springs 71° 11 normally bias the protrusions 73 of the sliding pieces γ0 and 70 in directions facing each other, and their ends abut against each other at the center of the disc-shaped case body 64. It is now possible to

The pressing piece 72 consists of a plate-shaped knob part 15 and a wedge-shaped cut-in part γ6 formed protruding from one side of the knob part 75.
It is rotatably attached to a support portion 71 fixed at 0 via a pin.

Then, when the suppressing piece γ2 is brought down and its interrupting portion 76 is inserted into the abutting portion of the two sliding pieces γ0 and 10,
Two sliding pieces 70°γ0 each have a coil spring 7
1.71, and at that time the locking piece 69°6 formed at the tip of the sliding piece 70, γ0
9 protrudes outward from the outer end of the disc-shaped case body 64.

The guide means 67 for the bobbin thread 41 includes the bobbin thread guide 18 and the tension spring 7.
It consists of 9.

The lower thread guide 78 has a semi-cylindrical shape with a threading hole 80 formed at its tip, and is connected to the disc-shaped case body 64.
A fitting shaft 6 formed in the main body 64 is provided on the peripheral edge of the main body 64.
It is formed to protrude in the same direction as 5.

Further, the tension spring 79 is formed such that its thread opening 81 communicates with the proximal end of the lower thread guide 18.

The bobbin 23 is made of a suitable material such as metal or synthetic resin and has a substantially similar shape to a conventional bobbin.

The suturing device 19 has the configuration described above,
Its assembly is done as follows.

First, the lower shaft fixing part 82 of the cauldron 21 is inserted into the tip of the lower shaft and fixed with the screw 51, thereby fixing the cauldron 21 to the lower shaft 52.

Next, the inner pot 20 is inserted into the large pot 21 with its open end facing forward, and the rear side surface of the support rib 26 formed on the inner pot 20 is brought into contact with the open end surface of the large pot 21.

After the large pot 21 and the inner pot 20 are combined, the inner pot holding lid 22 is fixed to the large pot 21.

Then, the inner pot presser lid 22 is fixed to the large pot 21 by screwing the fixing screw 83 into the fixing screw hole 63 of the large pot 21 through the screw insertion hole 62 formed in the inner pot presser cover 22.

Then, the inner pot 20 is fitted into the annular groove 84 formed by the supporting rib 26 or the open end surface of the large pot 21 and the protrusion 57 of the inner pot holding lid 22, and is prevented from coming off. The roller 34 provided slides on the circumferential surface of the annular groove 84, ensuring smooth rotation of the large hook 21 with respect to the inner hook 20.

In this case, the roller 34 provided on the support rib 26
If a small ball 36 as shown in FIG. 4 is used instead, the small ball 36 is formed so as to be in contact with each inner surface of the annular groove 84, so that the cauldron 21 can rotate more smoothly. can be achieved.

Next, after winding the bobbin thread 41 around the bobbin 23, it is held on the fitting shaft 65 of the bobbin case 24 in an external fit.

Incidentally, if the bobbin 23 is made of a relatively inexpensive material such as a synthetic resin and is supplied to the user with various bobbin threads 41 already wound, the bobbin can be disposed of. This has the advantage that the labor for winding the bobbin thread is saved and there is no need to provide the sewing machine with a device for winding the bobbin thread around the bobbin.

Moreover, if a removable cover is provided to cover the bobbin thus formed, dust will not adhere to the bobbin thread or the bobbin thread may become discolored.

This reduces the amount of damage and provides favorable storage advantages.

After holding the bobbin 23 in the bobbin case 24, the bobbin thread 41
The thread is passed through the bobbin thread passing hole 80 of the bobbin thread guide 78 provided in the bobbin case 24 and guided out of the bobbin case 24 through the thread opening 81 of the tension spring 19 through the groove.

Then, the bobbin case 24 is installed in the inner hook 20. In this case, the bobbin thread guide γ8 provided on the bobbin case 24 is fitted into the fitting groove 44 formed on the inner surface of the inner hook 20, and the inner hook is opened. The insertion shaft 65 of the bobbin case 24 is externally fitted onto the pin 42 of the bobbin case 20.

When putting the bobbin case 24 into the inner hook 20, the pressing piece 12 of the locking mechanism 66 of the bobbin case 24 is raised, and when the bobbin case 24 is completely inserted into the inner hook 20, the locking mechanism 66 The pressing piece γ2 is brought down to insert its interrupting portion 76 between the abutting portions of the two sliding pieces 70, 70.

Then, the two sliding pieces γ0, 10 are made to slide outward against their respective coil springs 7L71, and the locking pieces 69, 69 engage the engagement recesses 43° formed on the inner surface of the inner hook 20, respectively. 43, thereby completing the attachment of the bobbin case 24 to the inner hook 20.

Then, the tongue of the rotation prevention finger is engaged with the notch 39 formed at the top of the inner pot 20, so that when the lower shaft 52 rotates, only the large pot 21 and the inner pot holding lid 22 rotate in the direction of the arrow. Make it.

Next, the operations of the above-mentioned balance mechanism 1 and suturing device 19 will be explained.

The needle 15 with the upper thread 18 pierces the cloth and emerges from the underside thereof, advances to a point where the extra length of the needle 15 is accumulated from the top of the inner hook, and then moves upward.

The upper thread 18, which was taut when the needle 15 was at its lowest position, becomes sagging and becomes a loop.

At the same time, the needle thread scooping part 58 and the extra length of the needle 15 intersect,
The upper thread scooping section 58 scoops up the looped upper thread 18 (
(See Figure 1C).

While the balance weight 5 rotates approximately 1/4 turn with the two needle thread pull-up levers γ and 7 remaining substantially spread, the needle thread scooping section 58 that scoops up the ring-shaped needle thread 18 is in the state shown in FIG. 1A. The looped upper thread 18 is just about to pass through the back of the hook 20.

At this time, the thread removal guide 37 is attached to the slider 28 of the inner hook 20.
, the ring-shaped upper thread 18 is guided so as to reliably pass through the inner hook 20 (see FIG. 1C).

The needle 15 continues to rise further, and when the balance weight 5 rotates approximately half a turn from the state shown in FIG. 1A, the needle thread scooping portion 58 rotates once and returns to its original position.

While the needle thread scooping section 58 rotates once and returns to its original position, the needle thread passes through the inner hook 20, so the needle thread scooping section 58 also comes off, and at the same time, the two needle thread pull-up levers 1 and 7 become acute-angled. The ends of these threads approach each other, and at this time, the needle thread 18 that has passed through the inner hook 20 is suddenly pulled up (see FIG. 1C).

At this time, the bobbin case 24 also comes out and the bobbin thread 41, which has reached the fabric, becomes entangled with the upper thread 18, creating one stitch.

Then, while the balance weight 5 is making the remaining half-rotation, the two needle thread pull-up levers 7.1 are opened again, and at the same time, the cauldron 21 is made one revolution.
8 and the cloth is sufficiently tightened,
This completes the seam formation (see first diagram).

The above-mentioned operations are repeated to complete a predetermined stitch.

As described above, the thread take-up mechanism of the full-rotation sewing machine of the present invention has two needle thread pull-up levers, and the upper thread is pulled up by constantly rotating them in opposite directions about the same center. Therefore, it is possible to sufficiently take up the slack in the needle thread and quickly restore the original tension after the needle thread has passed through the suturing device, making it possible to increase the size of the suturing device. The amount of protrusion of the tip outside the bracket arm can be reduced, so the user can work with peace of mind.

[Brief explanation of drawings]

1 and 2 show an example of the implementation of the thread take-up mechanism of the full-rotation sewing machine of the present invention, FIG. 1 A is a side view of the bracket arm cut away, and FIGS. Figure 2 schematically shows the movement with the device, Figure 2 is a cross-sectional plan view, Figures 3 to 6 are examples of the suturing device, Figure 3 is an exploded perspective view, and Figure 4 is an outer peripheral support. FIG. 5 is a plan view of the inner hook, and FIG. 6 is a front view of the bobbin case. Explanation of symbols, 1... Balance mechanism, 2... Sewing machine component (bracket arm), 3... Arm shaft, 5...
Balance weight, 6...pin (for operating the balance mechanism and driving the needle bar)
, 7... Needle thread pull-up lever, 11... Anchor link.

Claims (1)

[Claims] 1. A balance weight is fixed to the tip of the arm shaft, and a pin for operating the balance mechanism and driving the needle bar is fixed at an eccentric position of the balance weight,
One ends of two needle thread pull-up levers of the same shape and size are rotatably supported on the pins so as to face in opposite directions, and one end of each of the two needle thread pull-up levers is rotatably supported. The tip of an anchor link rotatably supported is connected to sewing machine component members spaced apart from each other at equal distances in opposite directions from a vertical line passing through the center of the arm axis. A full-rotation sewing machine balance mechanism featuring: