JPS63281688A - Inner hook rotation stop 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] The present invention is directed to an inner hook rotation stopper device of a sewing machine that mechanically sews together two or more pieces of fabric or other workpieces, particularly for an outer hook. This invention relates to an inner hook detent device which allows a sewing thread caught by a hook to be detached without receiving excessive catching resistance when it passes through the inner hook detent part.

[Conventional technology]

The hook-related mechanism of a sewing machine is the core element of the sewing machine, and generally includes an outer hook that rotates at high speed, an inner hook that is rotatably housed within the outer hook, and an inner hook that is rotatably housed within the inner hook. It consists of a bobbin and a bobbin wound with bobbin thread, and the inner hook is prevented from rotating.

Conventionally, as shown in FIG. 7, as shown in FIG. 7, a hook 2 is provided on the outer periphery of the upper end of the inner hook 1 to protrude outward, and a claw 2 is provided on the outer periphery of the upper end of the inner hook 1, and a hook 2 is provided on the lower surface of the throat plate 3. A recess 4 is formed in the protrusion 3a, and by engaging the pawl 2 with the recess 4, the inner hook 1 accommodated in the outer hook (not shown) is prevented from rotating.

Therefore, the upper thread passed through the workpiece by the sewing machine needle and delivered to the hook mechanism is caught by the hook of the outer hook which rotates at high speed, and is caught by the hook of the outer hook which rotates at high speed. By passing it around the thread, it intersects with the bobbin thread. Then, when a tensile force is applied to the needle thread by the thread take-up, the needle thread passes through between the pawl 2 and the recess 4 of the inner hook 1, and the nail puller is sufficiently pulled toward the exit side, thereby sewing the workpiece onto the workpiece. The eyes will be formed and the workpiece will be sutured.

[Problem that the invention seeks to solve]

In the conventional inner rotor locking device as described above, the inner rotor 1
Since the claw 2 protruding from the inner hook 1 is engaged with the recess 4 provided on the lower surface of the throat plate 3 to prevent the inner hook 1 from rotating, when the outer hook rotates at high speed, the inner hook 1 can rotate relative to the inside of the outer hook. A considerably large torque is generated in the supported inner hook 1 in the rotational direction of the outer hook due to the 11m resistance of its supporting portion, and as a result, one side of the highly rigid pawl 2 is attached to the end surface of the recess 4 with a relatively large torque. They stick together under pressure and restrict the upper thread from slipping through. For this reason, if the needle thread is rapidly pulled by the pull-up operation of the thread take-up, an excessive tensile force is applied to the needle thread, which may cause the thread to break, or the sewing thread may be sewn onto the workpiece due to excessive tension. There are problems that occur to me.

In addition, in the conventional inner hook locking device, the recess 4 in which the pawl 2 engages is formed on the lower surface of the throat plate 3, so the engagement operation between the two is completely blind, and the state after engagement is cannot be checked or corrected from the outside, and as a result, if the two are not properly aligned, it may cause major problems in sewing, or
A problem arises in which the sewing machine's hook mechanism is damaged.

Furthermore, due to its structure, it is necessary to assemble the sewing machine from time to time in order to secure the connection between the claw of the inner hook and the recessed part, and as it is not possible to assemble the individual parts in advance outside the sewing machine, please check the assembly status before assembling. This made maintenance and inspection work by general users more difficult.

This invention was made in order to solve the above-mentioned conventional problems, and allows the upper thread caught by the hook of the outer hook to move smoothly through the detent retaining portion of the inner hook without receiving large catching resistance. To provide an inner hook rotation stopper device for a sewing machine that can be passed through, prevents cutting of sewing threads and generation of sewing wrinkles, and allows maintenance and inspection of the engagement state of an inner hook rotation prevention mechanism from the outside.

[Means for solving problems]

The inner hook rotation prevention device for a sewing machine according to the present invention has an outer circumference t! of an inner hook that is relatively rotatably inserted into an outer hook constituting a hook mechanism of a sewing machine. ! 4s, forming a detent notch at a desired angle away from the lowered position of the sewing needle in the direction of rotation of the outer hook, and further forming a desired corneal layer from the notch in the direction of rotation of the outer hook to form a protrusion; The hook mechanism mounting base is provided with a swinging arm that rotates horizontally in conjunction with the rotation of the outer hook, and the swinging arm has a claw that engages with the notch to prevent the inner hook from rotating. and an opener member that engages with the protrusion to alternately rotate the inner hook in a direction opposite to the rotational direction of the outer hook to temporarily release the locked state between the claw member and the notch. It was established.

[For production]

In this invention, when the upper thread caught by the hook of the outer hook passes between the notch and the claw member, the opener member engages with the protrusion due to the rotational action of the swing arm, and the inner thread is moved from the outer hook to the outer hook. It is instead rotated in the opposite direction to the rotational direction to temporarily release the engagement between the notch and the pawl member to create a gap through which the upper thread can easily pass. Therefore, the upper thread is threaded 9 times in the inner hook.
It will pass through the stop smoothly and reliably,
When pulling up the upper thread with a thread take-up, no more tension than necessary is applied to the upper thread.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a partially cutaway front view showing the overall configuration of a sewing machine equipped with an inner hook rotation prevention device according to the present invention,
10 is a sewing machine bed, 11 is a sewing machine arm installed on the sewing machine bed 10, and 12 is an upper shaft rotatably supported on a bearing 13 in the horizontal part of the sewing machine arm 11; A pulley 14 is fixed to the projecting end and is connected to a drive source (not shown) such as a motor with a belt, and a crank 15 is attached to the front end of the sewing machine arm of the upper shaft 12. One end of a crank rod 17 is rotatably attached to the crank 15 by a crank pin 16, and the other end of the crank rod 17 is connected to a needle bar 19 via a connecting portion 18.

The needle bar 19 is supported by a bracket 20 fixed to the front end of the sewing machine arm 11 so as to be movable up and down.
A pair of sewing needles 21A and 21B are attached to the lower end of the needle bar 19. Reference numeral 22 denotes a well-known thread take-up which is attached to the front end of the sewing machine arm 11 so as to be rotatable in the vertical direction, and rotates in the vertical direction in relation to the interlocking movement of the needles 21A and 21B, thereby moving the needles 21A and 21B to the workpiece. When the outer hook (described later) pulls the needle thread through the object,
Give sufficient slack to the upper thread, and when the upper thread and lower thread intersect and the needles 21A and 21B move upward, pull up the upper thread sufficiently to apply tension to the upper thread and sew lockstitch on the workpiece. It forms the eyes.

Further, in FIG. 1, reference numeral 23 denotes a lower shaft rotatably supported by bearings 24, 25a, and 2Sb on the lower surface side of the sewing machine bed 10, and a belt pulley 26 is fixed to one end of the lower shaft.
A timing belt 28 is wound between this belt pulley 26 and a belt pulley 27 fixed to the upper shaft 12, thereby transmitting the rotation of the upper shaft 12 to the lower shaft 23. 29A.

29B is a rotary hook mechanism installed in the sewing machine bed 1 facing the needle bar 19, and a sewing needle 21A attached to the needle bar 19;
21B respectively.

The hook mechanisms 29A and 29B are mounted on mounting bases 30A and 3.
0B, and each of the mounting bases 30A and 30B is connected to a slotted hole 31 and a round hole 32 formed therein, and screws 33 and 34 pushed through these, respectively, as shown in FIGS. The sewing needles 21A, 21B are attached to the bed 10 so that their attachment positions can be adjusted, and the mounting bases 30A, 30B have bearings 36A, 35B that pass vertically through the mounting bases 30A, 30B. 36B
The hook shaft 35A is rotatably attached to the pivot shaft.
, 35B are fixed to screw gears 37A, 37B, and these screw gears 37A, 37B mesh with screw gears 38A, 38B (only one is shown in FIG. 3) attached to the upper shaft 23. As a result, the rotation of the lower shaft 23 is transmitted to the respective hook shafts 35A and 35B. Further, the lower surfaces of outer hooks 39A and 39B are fixed concentrically to the upper ends of the hook shafts 35A and 35B, and the upper surfaces of these outer hooks 39A and 39B are open, and on the outer periphery there is a slot for catching the upper thread 40. It has a hook 39a (see FIGS. 2 and 3). Outside hook 39A,
Inner pots 41A and 41B are stored in 39B.
, these inner hooks 41A, 41B have a protrusion 43 that engages with a race groove 42 formed in a ring shape on the inner wall of the outer hook 39A, 39B, and a protrusion 43 that is inserted into the race groove 42, as shown in No. 31flJ. It is held rotatably relative to the outer hooks 39A, 39B by a holding member 44, and a bobbin shaft 45 is located at the center of the inner hooks 41A, 41B.
is vertically protruding, a bobbin 46 is rotatably fitted onto the bobbin shaft 45, and a bobbin presser 47 connected to the bobbin shaft 45 holds the bobbin 46 in the inner hooks 41A, 41.
It is held so that it does not fall off from B. Further, 48 is the bobbin thread wound around the bobbin 46, and 49 is the inner hook 41A.
.

This is a flange formed at the opening edge of 41B.

The flanges 49 of the inner hooks 41A and 41B are shown in FIG.
As shown in FIGS. 4 and 5, sewing needle 21A (21B>
A notch 50 for preventing rotation of the inner hook is formed at a distance of about 120 degrees from the position of the outer hook in the direction of rotation of the outer hook (arrow A).
A protrusion 51 is formed. Further, 52 is a swing arm whose one end is horizontally rotatably attached to the upper surface of the mounting base 30A (30A) with a pivot pin 53. One end of the link 55 is rotatably connected by a pin 54, and a ring portion 55a provided at the other end of the link 55 is connected to the hook shaft 35A (
35B) Disc-shaped eccentric part 5 formed eccentrically at the upper end
6 is rotatably fitted.

The swing arm 52 has support portions 52a and 52b rising upward at right angles at both ends thereof, and one of the support portions 52
At the upper end of a, there is a notch 5 of the inner pot 41A (41B).
A claw member 57 that engages with the inner hook 41A (41B) to prevent it from rotating is fixed by a screw 58, and is attached to the upper end of the other support portion 52b.
The opener member 59 that engages with the protrusion 51 of B) and rotates the inner hook 41A (41B) slightly in the direction opposite to the direction of rotation of the outer hook 39A (39B) (direction of arrow A) is the screw 60.
It is fixed by.

In addition, in FIG. 1, 61 is the throat plate provided on the ped 10, 62 is the feed dog of the workpiece, 63 is the hook mechanism 29A,
This is a sliding board attached to the bed 10 so as to be openable and closable in correspondence with the bed 29B.

Next, the operation of this embodiment configured as described above will be explained.

When the upper shaft 12 rotates when the sewing machine starts operating, this rotation is transmitted to the crank 15, and as the crank 15 rotates, the crank rod 17 moves in conjunction with the crank, causing the needle bar 19 to move up and down. The balance 22 also rotates in the vertical direction.

On the other hand, the rotation of the upper shaft 12 is transmitted to the lower shaft 23 via the belt shafts 27, 26 and the timing belt 28, and further to each hook mechanism 29A via screw gears.

By rotating the hook shafts 35A, 35B of the hook 29B, the outer hooks 39A, 39B are rotated at high speed.

When the outer hooks 39A and 39B rotate, the sewing needles 21A and 24
The hooks 39a of the outer hooks 39A and 39B catch the needle thread 40 pushed out to the hook mechanism side by penetrating the workpiece (not shown) by the hook B at the position shown in FIG.

39B rotates in the direction of arrow A in FIG.
are sequentially drawn in as shown in FIG. At this time, since the thread take-up 22 is rotated downward, sufficient slack is given to the upper thread 40, so that the upper thread 40 is drawn in smoothly.

On the other hand, when the hook shafts 35A and 35B rotate, the flawed center portion 56 provided thereon rotates eccentrically, so that the link 55
The swinging arm 52 connected via the pivot pin 53 is swung back and forth in the directions of arrows B1 and B2 in FIG.

That is, as the needle thread hook of the hook 39m comes to a position facing the claw member 57, when the swinging arm 52 is rotated in the direction of the arrow B1 in FIG. 4 using the pivot pin 53 as a fulcrum, The opener member 59 engages with the protrusion 51 of the inner hook 41A (41B) and rotates the inner hook 41A (41B) slightly in the direction opposite to the arrow A. Then, the edge 5 of the notch 50
0a is separated from the claw member 57, a gap is created between the two, and the claw member 57 is placed in a non-contact state with the notch 50. Therefore,
The needle thread 40 caught by the hook 39a is caught in the gap between the forcibly formed notch 50 and the claw member 57, and passes through the outer hook 39A (39B) without receiving much resistance.
It passes smoothly due to the tensile force that accompanies the rotation.

Then, when the outer hook 39A (3913) is rotated from the position 1a shown in FIG. 4 to nearly 180° in the direction of arrow A,
The swinging arm 52 is rotated in the direction of arrow B2 in FIG.
9 separates from the protrusion 51 of the inner kayak 41A (41B). Thereafter, when the thread take-up 22 is rotated upward, the upper thread 40 is pulled up above the throat plate 61 in a state where it intersects with the C thread (not shown). form a seam. When the thread take-up 22 pulls up the needle thread 40, the needle thread 40 completely passes through the position of the claw member 57 and the notch 50 where it engages, and the opener member 59 is spaced apart from the protrusion 51. In this way, the tensile force that occurs when forcing the needle thread 40 to pass between the claw 2 and the recess 4 does not act on the needle thread 40 in the same way, and there is no possibility that an excessive tensile force will act on the needle thread 40. Therefore, it is possible to prevent sewing wrinkles from occurring due to the upper thread 40 being cut or excessive tension being applied, and beautiful seams can be created.

Also, when the sliding plate 63 is opened, the inner pot 41A (41B)
The detent mechanism appears completely within its opening area, so
The engagement state of the claw member 57 with respect to the notch 50, the positional relationship between the protrusion 51 and the opener member 59, etc. can be easily confirmed,
Moreover, these adjustments and corrections can be easily made.

〔Effect of the invention〕

As described above, according to the present invention, the notch is formed in the outer peripheral flange of the inner hook, which is relatively rotatably housed in the outer hook, at a distance of about 120 degrees from the lowered position of the sewing needle in the rotational direction of the outer hook. Furthermore, a protrusion is formed at a position a desired angle away from this notch in the direction of rotation of the outer hook, and a swinging arm that swings horizontally in conjunction with the rotation of the outer hook is provided on the mounting base of the hook mechanism. , the swinging arm is provided with a claw member that engages with the notch to prevent the inner hook from rotating, and an opener member that engages with the protrusion, so that the upper thread caught by the hook of the row hook is When the notch and the pawl member are brought into contact, the opener member is engaged with the protrusion and the inner hook is slightly rotated in the direction of rotation of the outer hook and the direction of the connection, thereby locking the notch and the pawl member. As the upper thread is temporarily released, the upper thread caught by the hook of the outer hook moves through the gap between the released pawl member and the notch as the outer hook rotates. The upper thread passes smoothly, the resistance when passing the upper thread is extremely small 9, and the upper thread passes reliably. As a result, when the sewing thread is pulled up with the thread take-up, excessive tension that would stretch or break the upper thread is not applied to the upper thread, thereby preventing the sewing thread from breaking or creating wrinkles. I can do things.

In addition, when the sliding plate is opened, the rotation prevention mechanism of the inner hook is
Since it appears within the opening, it is possible to easily check the engagement state of the inner locking mechanism, which has the effect of facilitating maintenance and inspection.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a sewing machine equipped with an inner rotary hook locking device of the present invention, FIG. 2 is a plan view of a hook mechanism in an embodiment of the present invention, and FIG. -1 is a sectional view taken along line 1, FIGS. 4 and 5 are plan views showing the operating state of the detent portion of the hook mechanism in the embodiment of this invention, and FIG. 6 is a sectional view taken along line 1. FIG. 7 is a plan view showing details of the swing arm and its operating mechanism, and FIG. 7 is a perspective view of the main parts of a conventional inner hook locking mechanism. 10-... Bed, 11... Sewing machine arm, 12...
Upper fi, 15=-crank, 17... Crank rod, 19... Needle bar, 21A, 21B... Sewing needle, 22.
... Balance, 23... Lower shaft, 29A, 29B... Hook mechanism, 30A. 30B...Mounting stand, 35A, 35B...Kook shaft, 37
A, 37B...screw shaft, 39A, 39B...outer hook,
40...Upper thread, 39a--hook, 41A, 41B...
Inner hook, 46...Bobbin, 48...Lower thread, 49...
- Flange part, 50... Notch, 51... Claw part, 52... Swinging arm, 55... Link, 56... Eccentric part, 57... Detent claw member, 59... Opener member, 61 ...
Throat plate, 63 sliding plate. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) ts2 Figure 3 Figure 4 Figure 5 Figure 4 Figure 7

Claims (1)

[Claims] A needle bar is supported on the sewing machine arm so that it can move up and down in synchronization with the sewing cycle so that the sewing needle can pass through the workpiece with the upper thread and move up and down, and a needle bar that is installed on the sewing machine bed in correspondence with the needle bar and the above-mentioned A hook mechanism is provided for making the upper thread intersect with the lower thread while the sewing needle is penetrating the workpiece, and the sewing machine arm is provided so as to be able to rotate vertically in synchronization with the sewing cycle, and is provided to loosen and tension the upper thread. The hook mechanism includes an outer hook that is pivotably supported on a mounting base so as to be horizontally rotatable in synchronization with the sewing cycle, and has a hook on its outer periphery that captures the upper thread; In a sewing machine comprising an inner hook that is relatively rotatably inserted into an outer hook, and a bobbin thread bobbin that is rotatably inserted into the inner hook,
A detent notch is formed in the outer peripheral flange of the inner hook at a desired angle away from the lowered position of the sewing needle in the rotational direction of the outer hook;
Further, a protrusion is formed at a desired angle away from the notch in the direction of rotation of the outer hook, and the hook mechanism mounting base is provided with a swinging arm that is horizontally rotated in conjunction with the rotation of the outer hook,
This swinging arm includes a claw member that engages with the notch to prevent the inner hook from rotating, and a claw member that engages with the protrusion to rotate the inner hook slightly in the opposite direction to the rotation direction of the outer hook. An inner hook rotation prevention device for a sewing machine, characterized in that an opener member is provided for temporarily releasing the locked state between the pawl member and the notch.