JPS6038475Y2 - Horizontal hook thread tangle prevention device - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention includes an outer hook having a tip that rotates in a plane substantially parallel to the sewing work surface, and an inner hook located within the outer hook and holding the bobbin. This invention relates to a horizontal hook of a sewing machine in which the rotation of the inner hook is regulated by a regulating member having a pair of engaging pieces that alternately engage and disengage from the inner hook in time with the rotation of the outer hook.

Purpose The purpose of this invention is to provide a protrusion adjacent to the locking piece on the lower surface of the throat plate disposed on the sewing work surface, on the side where the rotating sword tip faces at least one of the locking pieces. A strip is provided, and the protruding strip extends along the movement path of the tip of the locking piece, and is formed to protrude so that its lower surface is located below the tip of the locking piece, so that the upper thread can be threaded. To provide a thread entanglement prevention device for a horizontal hook that can surely prevent thread entanglement caused by a ring being caught on a locking piece, has a simple structure, and can be manufactured at low cost.

EXAMPLE An example embodying this invention will be described below with reference to the drawings. As shown in FIGS. 1 and 3, the upper surface of the bed of the sewing machine frame 1 has a needle through hole 2a, a feed dog opening 2b, and A throat plate 2 having a cutout recess 2c is attached.

A sliding plate 3 is attached to this notched recess 2c so as to be openable and closable.

The upper surface of the bed, the needle plate 2 and the slide plate 3 constitute a sewing work surface P.

A horizontal hook 4 is provided below the throat plate 2 and on a vertical axis within the bed section.

This horizontal hook 4 is composed of an outer hook 5 which is rotated around the -vertical axis and an inner hook 6 whose rotation is restricted within the outer hook 5.

Then, the outer hook 5 of the horizontal hook 4 passes through the needle through hole 2a in a plane substantially parallel to the sewing work surface P.
The sewing machine is rotated twice in one direction for each reciprocating movement, so that a lock stitch is formed on the work cloth.

The outer pot 5 is formed into a substantially bottomed cylindrical shape with an open upper surface, and a shaft cylindrical portion 8 is protruded from the lower surface thereof.

A gear 9 and a cam surface 10 are integrally formed on the outer periphery of the shaft cylinder portion 8, and the gear 9 meshes with a gear (not shown) on the lower shaft of the sewing machine.

A lace portion 11 is formed on the inner periphery of the upper portion of the outer hook 5, and a tip 12 for catching the upper thread carried by the needle 7 is formed in a part of the lace portion 11.

On the other hand, the inner hook 6 is formed of a synthetic resin material into a substantially bottomed cylindrical shape with an open upper surface, and is capable of accommodating a pobbin 13 around the center of which the bobbin thread is wound.

Then, the flange 14 of the inner hook 6 is connected to the race portion 11 of the outer hook 5.
The inner hook 6 is housed in the outer hook 5 in a state where it is engaged from above.

The flange 14 of the inner hook 6 is formed with a needle drop groove 15 and an inclined surface 16 located on the rotation locus of the tip 12,
The needle thread ring captured by the tip 12 during sewing operation of the sewing machine follows this inclined surface 16 and easily passes through the inner hook 6.

Further, a finger rest recess 14a is formed in the flange 14, and the bobbin 13 in the inner hook 6 can be easily removed by inserting a finger into this finger rest recess 14a.

As shown in FIG. 2, a regulating member 17 is supported within the bed portion behind the shaft cylinder portion 8 of the outer pot 5 so as to be swingable around a vertical axis. The cam follower 18 is attached to the outer hook 5 by a tension spring (not shown).
is engaged with the cam surface 10 of.

Locking pieces 19a and 19b are integrally formed on the regulating body 17 so as to be located between the outer hook 5 and the throat plate 2, and are formed on the movement path of both the locking pieces 19a and 19b. A pair of locks R20a, 20b are provided on both sides of the needle drop groove 15 on the flange 14 of the inner hook 6 so as to be located at the flange 14 of the inner hook 6.
are formed respectively.

Based on the engagement of the cam follower 18 with the cam surface 10, when the regulating body 17 is swung around a vertical axis in time with the rotation of the outer hook 5, each of the locking pieces 19a,
19b alternately engages and disengages from each locking groove 20a, 20b,
The rotation of the inner hook 6 is regulated, and the free end of the upper thread and the lower thread let out by the upper thread thread loop is secured to each locking piece 19a.
, 19b and each locking groove 20a, 20b.

One of the locking pieces 1 of the pair of locking pieces 19a and 19b
A protrusion 21 that protrudes toward the needle plate 2 is integrally formed at the tip of 9a.

Further, on the side where the tip 12 faces from the front of one of the locking pieces 19a, a protrusion 23 is fixed to the lower surface of the throat plate 2 by two screws 22 adjacent to the one of the locking pieces 19a. has been done.

The protrusion 23 extends along the moving path of the protrusion 21 of the one locking piece 19a, and is formed to protrude so that its lower surface is located below the tip of the protrusion 21. It is adapted to engage the inner edge of the

As the regulating body 17 swings, as shown in FIG.
As is clear from b, the protrusion 21 of one locking piece 19a
is engaged with the inner edge of the protrusion body 23, and the protrusion body 2
It is reciprocated along 3.

Further, when the regulating body 17 is disposed at the position shown in FIG. This prevents the upper thread separated from the upper thread 12 from going around to the vicinity of the proximal end of one of the locking pieces 19a or being caught by the locking piece 19a, thereby preventing the thread from becoming tangled.

Next, the operation of the horizontal hook 4 configured as described above will be explained.

Now, during the sewing operation of the sewing machine, the outer hook 5 rotates twice while the needle 7 moves once, and the rotation is regulated in synchronization with the rotation of the outer hook 5 based on the action of the cam surface 10 of the outer hook 5. When the body 17 is swung, the pair of locking pieces 19a and 19b alternately engage and disengage from the pair of locking grooves 20a and 20b on the inner hook 6, thereby restricting rotation of the inner hook 6.

Then, when the tip 12, which has caught the upper thread in the needle drop groove 15 of the inner hook 6, rotates counterclockwise in FIG. 1 and passes near the other locking groove 20b on the inner hook 6, When the pair of locking pieces 19a and 19b are moved to the position shown in FIG. 4, the needle thread is allowed to pass between the other locking groove 20b and the other locking piece 19b. At the same time, one locking piece 1
Rotation of the inner pot 6 is restricted by 9a.

As the outer hook 5 continues to rotate, when the tip 12 passes near one of the locks 120a on the inner hook 6, the pair of locking pieces 19a and 19b move to the position shown in FIG. 4a. At the same time, the rotation of the inner pot 6 is restricted by the other locking piece 19b, and at the same time, the protrusion 21 of one of the locking pieces 19a is moved along the inner edge of the protrusion 23. Pot 6
One locking piece 19 near the outer peripheral edge of the flange 14
The protrusion 21 of a engages with the inner edge of the protrusion 23.

Therefore, among the upper thread detached from the tip 12 and the free end of the lower thread paid out from the bobbin 13 by the upper thread thread loop, the upper thread in particular is connected to the protrusion 21 of the one locking piece 19a and the protrusion 23. This prevents the upper thread from getting entangled with one of the locking pieces 19a, without intruding between the locking pieces 19a and getting around to the vicinity of the proximal end of one of the locking pieces 19a, or getting caught on the locking piece 19a. The screw reliably passes between one of the locking grooves 20a and one of the locking pieces 19a along the lower surface of the protrusion 21, and passes through the inner pot 6 smoothly.

separate Next, a separate version of this invention will be explained with reference to FIG.

In this separate case, one locking piece 19 of the regulating body 17 is
a is formed in a plate shape, the lower surface of the protruding strip 23 is located below the upper surface of one of the locking pieces 19a, and the outer edge of one of the locking pieces 19a is engaged with the inner edge of the protruding strip 23. This embodiment differs from the previous embodiment in that it is possible to do so.

Therefore, when the tip 12 passes near one of the locks 120a on the inner hook 6 as the outer hook 5 rotates, the outer edge of one of the lock pieces 19a touches the inner edge of the protrusion 23. The flange 14 of the inner pot 6 is moved along the protrusion 23 in the engaged state.
The outer edge of the tip of one locking piece 19a engages with the inner edge of the protruding strip 23 near the outer peripheral edge of the locking piece 19a.

Therefore, among the upper thread detached from the tip 12 and the free end of the lower thread paid out from the bobbin 13 by the upper thread thread ring, the upper thread in particular enters between the one locking piece 19a and the protrusion 23. Therefore, the needle thread does not go around to the vicinity of the proximal end of one of the locking pieces 19a or get caught on the locking piece 19a, and the needle thread is prevented from becoming entangled with the one of the locking pieces 19a.

In each of the embodiments described above, the protrusion 23 was fixed to the throat plate 2 adjacent to only one of the locking pieces 19a; however, as is clear from FIG. Piece 1
This is because the tip 12 approaches 9b from behind and the needle thread loop does not widen significantly, and the needle thread rarely gets caught on the other locking piece 19b.

Then, if necessary, the protrusions 23 are fixed to the throat plate 2 adjacent to the pair of locking pieces 19a and 19b, and each locking piece 1
The upper thread can be passed more reliably between 9a, 19b and each of the locks 120a, 20b.

Furthermore, in each of the embodiments described above, the protrusion 23 is attached to the throat plate 2.
Although it is fixed to the sliding plate 3, it is also possible to fix it to the sliding plate 3.

Effects As detailed above, in this invention, on the lower surface of the throat plate disposed on the sewing work surface, a tip that rotates in a plane substantially parallel to the sewing work surface faces at least one of the locking pieces. A protrusion is provided adjacent to the locking piece on the side, and the protrusion extends along the movement path of the tip of the locking piece, and the lower surface thereof is located below the tip of the locking piece. By forming the protrusion in this manner, it is possible to reliably prevent the upper thread thread ring from being caught on the locking piece and causing thread tangling, and it has an excellent effect that the structure is simple and can be manufactured at low cost.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of a sewing machine embodying this invention, with Figure 1 being an exploded perspective view showing the horizontal hook and its related mechanisms, and Figure 2 being a perspective view of the regulating body. , FIG. 3 is a side sectional view of the horizontal hook and its related mechanism, and FIGS. 4 a and b are perspective views showing the operating states of the horizontal hook and the regulating body, respectively.
FIG. 5 shows a separate version of this invention, and is a side sectional view corresponding to FIG. 3. Throat plate 2, outer hook 5, inner hook 6, tip 12, bobbin 13, regulating body 17, pair of locking pieces 19a, 19b1 protruding strip body 23,
Sewing work surface P0

Claims (1)

[Claims for Utility Model Registration] The sewing machine includes an outer hook 5 having a tip 12 that rotates in a plane substantially parallel to the sewing work surface P, and an inner hook 6 located within the outer hook 5 and housing a bobbin 13. In a horizontal hook of a sewing machine, the rotation of the inner hook 6 is regulated by a regulating member 17 having a pair of engaging pieces 19a and 19b that alternately engage with and disengage from the inner hook 6 in synchronization with the rotation of the outer hook 5. , on the lower surface of the throat plate 2 disposed on the sewing work surface P,
A locking piece 19a is provided on the side where the rotating sword tip 12 faces at least one of the locking pieces 19a, 19b.
has a protrusion 23 provided adjacent to the protrusion 23, which extends along the moving path of the tip of the locking piece 19a and whose lower surface is below the tip of the locking piece 19a. A thread entanglement prevention device for a horizontal hook, characterized in that it is formed in a protruding manner so as to be positioned in the horizontal hook.