JPH0221006Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inner pot of a vertical full-rotation pot.

[Conventional technology]

When sewing on a general sewing machine, a loop of upper thread supplied from a needle is caught by a thread scooping part formed in the shape of a sword point in an outer hook, and the loop is passed around an inner hook that holds the bobbin thread. The stitches are made by crossing the bobbin thread. In recent years, the materials used for sewing have diversified, and new fabrics and threads have been developed one after another.
In particular, the recent trend is for many threads to be stretchable, and in particular, threads that stretch rapidly have poor thread slippage, which delays thread passing around the inner hook, disrupts the timing of needle thread removal during stitch formation, and causes skipped stitches. This has become a major problem, with some cases causing thread breakage due to thread biting. As a countermeasure for this, the entire inner hook is coated with a soft resin, and the thread dividing part provided at one end of the raceway of the inner hook, which rotatably fits into the track groove provided on the inner wall of the outer hook, is moved backwards. In some cases, specifications have been changed to prevent the thread from digging into the outer hook track groove even if the thread separation in the inner hook is delayed, but in these cases, the former does not cause thread slippage when it is first used. No problems occur, but the coating made of soft resin cannot thicken the epithelial membrane that maintains the accuracy of the rotating parts, and because it is on the order of microns, the parts that the threads are constantly in contact with are not durable and wear out quickly, causing the skin to appear. The same problem as the conventional product occurs. In addition, since the length of the track, which is the rotating sliding part, is shortened in the latter, play in the inner pot increases during rotation, increasing the rate of noise generation and causing new problems, making it difficult to put it into practical use.

[Problem that the invention aims to solve] This invention was devised in view of this point, and Figure 1 is a diagram of thread passing when using the conventional inner pot.
As shown in the figure, the connection between the base 18 and the bottom surface 19 of the track 12 has a small inclination angle A, and forms a vertical wall 20 at the top. For this reason, in order for the needle thread 21 to pass, that is, for the needle thread 21 to go around to the bottom surface 19, a large resistance is applied, which delays the thread passing, and the timing of the needle thread coming out during stitch formation is incorrect, resulting in skipped stitches. This will result in thread breakage.

[Means for solving problems]

In this invention, in the inner hook 2, the center 14 of the fitting part 8 into which the bobbin case for storing the bobbin wound with bobbin thread is fitted is aligned in the direction of the bobbin case latch groove 16 with respect to the center 15 of the track. The inner wall 22 of the fitting part 8 into which the bobbin case is fitted, the inclined wall 23 connected to the root 18 of the track 12 and the bottom surface 19 of the inner pot.
The wall thickness B formed between the bobbin case latch groove 16 and the vicinity thereof is the minimum thickness, and the wall thickness at the opposite position is the maximum wall thickness B1, from the lower part 24 of the thread parting part 17 to the vicinity of the minimum thickness part. An inclined curved surface 26 whose inclination angle gradually increases toward the bottom surface 32 of the point 2 is cut.
4 and point 32 so that a boundary line 27 is drawn.

[Effect]

With the above structure, the needle thread 21 separated by the thread separating section 17 is instantly moved to the inclined curved surface 26 with a large angle of inclination by the rotation of the outer hook, as shown in FIG. Since the resistance force is small, the thread can be passed around the bottom surface 19 quickly and with good timing.

[Example of idea]

An embodiment of this invention will be described based on the drawings.

FIG. 2 is an assembled front view of the full-rotary hook. Reference numeral 1 indicates a cup-shaped outer hook with a portion cut away, and a drive shaft 3 is inserted into a boss hole (not shown) and screwed with a mounting screw 4. A track groove 5 is cut into the cup-shaped inner circumferential surface of the outer hook 1, and a sword-like thread scooping part 6 is formed at one end of the cup-shaped side wall. Reference numeral 2 denotes an inner hook, and a bobbin case fitting part 8 is formed in the center thereof, and a bobbin case fitting part 8 is provided with a support shaft 7 erected into which a bobbin case containing a bobbin wound with bobbin thread (not shown) is fitted. A partially notched flange 9 is formed on the periphery of the opening of 8, and an engagement groove 11 is formed on the upper surface of the flange 9, in which a locking piece 10 engages to prevent the inner pot from rotating together with the rotational movement of the outer hook 1. Also, on the outer periphery of the outer wall of the bobbin case fitting part 8, there is a partially cut track 12 which rotatably fits into the track groove 5 of the outer hook 1.
is formed. The track 12 of the inner hook 2 is fitted into the track groove 5 of the outer hook 1, and the crescent-shaped inner hook holding plate 1 is assembled.
3 is screwed onto the outer hook 1 to prevent it from falling off, thereby forming a full-rotation hook.

In this invention, the center 14 of the fitting part 8 of the inner hook 2 into which the bobbin case containing the bobbin wound with the bobbin thread (not shown) is fitted is moved approximately in the direction of the bobbin case latch groove 16 with respect to the center 15 of the track 12. The thickness B formed by the inner wall 22 of the bobbin case fitting part 8, the root 18 of the track 12, and the end of the vertical wall 20 connected to the bottom surface 19 of the inner pot 2 is adjusted by 0.5 mm eccentrically. The wall thickness is set to be the minimum near the latch groove 16, and the wall thickness is gradually increased in both circumferential directions, and the wall thickness is set to be the maximum wall thickness B1 near the position 31 facing the latch groove 16. The thickness is about the same as the wall thickness near the bobbin case latch groove 16, and the lower part 24 of the thread dividing part of the track and from this position are 160 degrees to 160 degrees along the track around the center 15 of the track. A V-shaped boundary is formed from a position 29 180 degrees away from the lower part 24 of the thread dividing part of the track toward a position 32 on the bottom surface 80 to 90 degrees apart along the track around the center 15 of the track. Line 24-32-2
9 is formed, the inclination angle A1 gradually increases in both left and right directions from the vicinity of the bobbin case latch groove toward the maximum thickness part, and the inclination angle A1 at the positions 24 and 29 is 17 to 19 degrees. The inclined curved surfaces 26 and 30 are provided such that the inclination angle A1 near 32 is approximately 90 degrees. With this improvement, the inclination angle A1 from the vicinity of the lower part 24 of the thread separating part 17 to the vicinity of the inner hook bottom surface 25 of the maximum wall thickness section is extremely large compared to the inclination angle A of the conventional inner hook, and the inner hook bottom surface of the maximum wall thickness section. At around 25 degrees, it becomes close to 90 degrees. For this reason,
Compared to the conventional hook shown in FIG. 1, during sewing, the needle thread 21 fed from a needle (not shown) quickly moves across the inclined curved surface 26 on the lower side of the thread parting part 17 as shown in FIG. Move to the bottom surface 19. Also, even if the needle thread 21 rides on the vertical wall 20, the needle thread 21 will be stuck in the V formed between the points 24 and 32.
Since there is one side 27 of the character-shaped boundary line, it is drawn in the direction of the inclined curved surface 26 with a large inclination angle, and the bottom surface 1 is quickly drawn.
It will move to 9. Incidentally, the inclined curved surface 30 and one side 28 of the V-shaped boundary line are for machining purposes, and are effective for weight reduction and balance.

[Effect of idea]

Since this idea was constructed by changing only one part as mentioned above, there is no particularly difficult processing, and the cost is almost the same as the conventional product.Functionally, it can be used quickly and reliably even with any type of thread with poor thread slippage. Since thread crossing is possible, it not only completely eliminates skipped stitches and thread breakage due to thread snagging, but also facilitates low-tension sewing of thin materials, which is considered technically troublesome in sewing work.
This has the effect of enabling sewing in a wide range from high tension to low tension.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional inner hook, showing the state immediately before the upper thread locked in the thread dividing portion moves from the inclined wall to the bottom surface. FIG. 2 is a side view showing the fully rotary hook in use. FIG. 3 is a front view of an inner pot showing an embodiment of this invention, which corresponds to the same time period as the conventional inner pot shown in FIG. 1. Figure 4 is a bottom view of the inner pot according to the present invention. FIG. 5 is a side view of FIG. 4, and FIGS. 6 and 7 are a sectional view taken along line XX and X1-X1 in FIG. 4, respectively. 1: Outer hook, 2: Inner hook, 5: Track groove, 8: Bobbin case fitting part, 14: Center of bobbin case fitting part, 15: Center of track track, 12: Track track, 17: Thread separation Part, 19: Bottom of inner pot, 21: Upper thread, 26, 3
0: Inclined curved surface, 27, 28: V-shaped boundary line.

Claims (1)

[Scope of utility model registration request] The bobbin thread is wound in the inner hook, which is rotatably fitted and held in the track groove of the rotating outer hook, and is locked in a predetermined position by a locking piece to prevent it from rotating together with the outer hook. The center of the fitting part into which the bobbin case to be stored inside the turned bobbin is fitted is made eccentric in the direction of the bobbin case latch groove with respect to the center of the track, and the inner wall of the bobbin case fitting part, the root of the track, and the inner pot are The wall thickness formed by the end of the inclined wall connected to the bottom surface is set to the minimum near the bobbin case latch groove 16, gradually increases in both circumferential directions, and reaches the maximum thickness near the position 31 facing the latch groove. As for the thick portion, the wall thickness at the inner hook bottom surface portion 25 of this maximum wall thickness portion is approximately the same as the wall thickness near the bobbin case latch groove, and
The lower part 24 of the thread dividing part of the track and from this position 160 degrees to 180 degrees along the track around the center 15 of the track
A V-shaped boundary line extends from the lower part 24 of the thread dividing part of the track toward the bottom position 32, which is 80 to 90 degrees apart along the track, centering on the center 15 of the track. 24-32-29 is formed, the inclination angle A1 gradually increases in both left and right directions from the vicinity of the bobbin case latch groove toward the maximum thickness part, and the inclination angle A1 at the positions 24 and 29 increases.
1 is 17 to 19 degrees, inclination angle A1 near position 32
An inner pot of a vertical full-rotation pot characterized by having an inclined curved surface whose angle is approximately 90 degrees.