JP2010046108A - Horizontal hook of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal hook of a sewing machine, capable of improving the sewing quality. <P>SOLUTION: The horizontal hook 1 of the sewing machine has an opener 100. The opener 100 abuts to a cam surface 11a of a rotating peripheral cam 11, and has a lever portion 17 which is operated based on the quantity of rotation of an opener shaft 16 according to the radius of oscillation of an arm portion 15 engaged with a square piece 14 disposed in a direct-operated shaft 12 which is directly operated according to the shape of the cam surface 11a. The lever portion 17 can be operated in a desired fashion by changing the design to adjust the radius of oscillation of the arm portion 15 without changing the design of the shape of the cam surface 11a to reduce or increase the quantity of displacement by the peripheral cam 11 even if the distance between the opener shaft 16 and a lower shaft 2 must be extended or shortened according to the design of the sewing machine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a horizontal hook for a sewing machine.

Conventionally, a horizontal hook of a sewing machine is held in an outer hook having a sword tip that captures an upper thread loop formed below a needle plate by a sewing needle by rotation about the hook shaft, and the outer hook. And a hook for storing a bobbin for supplying a lower thread.
An inner hook protrusion is provided on the upper outer edge of the inner hook toward the outer side in the radial direction, and the inner hook protrusion is loosely inserted between two needle plate protrusions formed on the lower surface side of the needle plate. When the outer hook connected to the lower shaft via the hook shaft is rotated with the rotation of the lower shaft, the outer hook is brought into contact with the race surface provided on the inner periphery of the outer hook. A rotational force in the same direction as the rotation direction of the hook acts, but the above-described inner hook protrusion is brought into contact with the needle plate protrusion located on the downstream side in the rotation direction to prevent the rotation of the inner hook. ing.

By the way, in order to form the seam by tying the upper thread and the lower thread, it is necessary for the upper thread to pass between the middle hook protrusion and the two needle plate protrusions. For this reason, on the horizontal hook of the sewing machine, the central hook is reversed to the upstream side in the rotational direction at a predetermined timing synchronized with the vertical movement of the sewing needle, and the central hook protrusion and the needle plate protrusion are separated from each other. And an opener that forms a gap between the needle plate protrusion on the downstream side in the rotation direction.
The opener includes an end face cam provided on the lower shaft, a sensing lever that contacts the end face cam, a lifter shaft that is rotated about an axis by a sensing lever that is actuated by the rotating end face cam, and a lifter shaft. A lifter lever provided on one end of the lifter is known. For example, a lifter lever that swings as the lifter shaft rotates acts on a contact portion provided on the outer edge of the inner hook. Therefore, a gap for allowing the upper thread to pass between the inner hook and the needle plate is formed for each needle (for example, see Patent Document 1).
Special table 2006-512121 gazette

However, in the case of the above-mentioned Patent Document 1, since a sensing lever having a length corresponding to the distance between the lower shaft provided with the end face cam and the lifter shaft is provided, the lower shaft and the lifter shaft are designed due to the design of the sewing machine. When it is necessary to arrange them apart from each other, the sensing lever must be designed longer.
If the displacement of the end cam is not increased as the sensing lever becomes longer, the rotation amount of the sensing lever for properly operating the opener cannot be obtained, but the operation of the sensing lever becomes more stable as the displacement by the end cam increases. Therefore, there is a problem that the opener malfunctions easily and sewing defects are likely to occur.

  An object of the present invention is to provide a horizontal hook for a sewing machine capable of improving the quality of a sewing product.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a horizontal hook for a sewing machine, an outer hook having a sword tip for capturing an upper thread loop formed by a sewing needle, and a sewing machine for rotating the outer hook. A lower shaft, an inner hook that is disposed in the outer hook and has a protrusion that is loosely fitted in a predetermined fitting portion, and a protrusion and a fitting portion that are periodically synchronized with the vertical movement of the sewing needle. And an opener that allows the upper thread loop to pass through the gap. The opener is fixed to the lower shaft of the sewing machine, and one end of the opener comes into contact with the cam surface of the outer cam and moves in the axial direction. A possible linear motion shaft, a biasing portion which is provided on the other end side of the linear motion shaft and biases one end portion to the cam surface, an engaged portion provided on the linear motion shaft, and an engaged portion A rotating shaft that has an engaging portion that engages with the shaft and rotates about its axis in accordance with the movement of the engaging portion that accompanies the linear movement of the linear motion shaft; With the rotation of the rotating shaft, characterized in that it comprises a lever portion abuts the middle hook.

  According to a second aspect of the present invention, in the horizontal hook of the sewing machine according to the first aspect, the engaged portion is a square piece, and the engaging portion is an arm portion having a concave portion engaged with the square piece. And

  According to a third aspect of the present invention, in the horizontal hook of the sewing machine according to the first or second aspect, the urging portion includes a first magnet provided at the other end portion of the linear motion shaft, and a repulsion with the first magnet. And a second magnet arranged so as to repel the first magnet by the second magnet, whereby one end of the linear motion shaft is biased toward the cam surface.

According to the present invention, one end abuts against the cam surface of the outer peripheral cam, and the linear motion of the linear motion shaft moving in the axial direction is converted into the rotation of the rotation shaft, and the lever portion of the opener is operated. Yes. For this reason, even if the lower shaft rotates at a high speed, the operation of the opener is little and the operation is stable, and a good seam can be formed.
Further, when a square piece is provided on the linear movement shaft and an arm portion is provided on the rotation shaft, the rotation of the linear movement shaft is prevented by the engagement between the square piece and the concave portion of the arm portion, and the operation of the opener is further stabilized.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  As shown in FIGS. 1 to 4, the horizontal hook 1 of the sewing machine is formed by an outer hook 3 that is rotated by a lower shaft 2 of the sewing machine, an inner hook 4 that is disposed in the outer hook 3, and a sewing needle (not shown). And an opener 100 that forms a gap for allowing the upper thread loop to pass therethrough.

The lower shaft 2 is a shaft that is rotated by driving a sewing machine motor (not shown), is supported by bearings 2a and 2b, and is supported so as to be rotatable about its axis.
A first bevel gear 5 is attached to the lower shaft 2, and a hook shaft 7 rotatably supported by bearings 7 a and 7 b is attached to a second bevel gear 6 that meshes with the first bevel gear 5. It is attached.
Then, the rotational drive of the lower shaft 2 is transmitted to the hook shaft 7 via the first bevel gear 5 and the second bevel gear 6 so that the outer hook 3 rotates.

As shown in FIGS. 2 and 3, the outer hook 3 has a sword tip 31 that captures an upper thread loop formed by a sewing needle (not shown).
The inner hook 4 has a protrusion 41 that regulates its own rotation accompanying the rotation of the outer hook 3 by loosely fitting into a fitting portion 81 formed on the lower surface of the needle plate 8. Further, a bobbin (not shown) for supplying a lower thread is stored in the inner hook 4.
In the sewing machine, the configuration and operation of the outer hook 3 and the inner hook 4 for forming the seam by interlacing the upper thread and the lower thread are the same as those conventionally known and will not be described in detail here.

  The opener 100 includes an outer peripheral cam 11 that is rotated by the lower shaft 2, a linear motion shaft 12 that is disposed in a direction substantially perpendicular to the lower shaft 2, and whose one end 121 abuts against the cam surface 11 a of the outer peripheral cam 11, and linear motion An urging portion 13 provided on the other end side of the shaft 12, a square piece 14 that is an engaged portion provided on the linear motion shaft 12, and an arm portion 15 that is an engaging portion that engages with the square piece 14. , An opener shaft 16 that is a rotation shaft including the arm portion 15, a lever portion 17 fixed to the upper end portion 161 of the opener shaft 16, and the like.

The outer peripheral cam 11 is attached to the lower shaft 2 by a screw N and rotates together with the lower shaft 2.
The outer peripheral cam 11 is formed with a cam surface 11a that is recessed so that the distance from the axis of the lower shaft 2 to the outer peripheral surface of the outer peripheral cam 11 is shortened by one place.
The recessed point of the cam surface 11 a corresponds to the operating position of the opener 100.

The linear motion shaft 12 is supported by bearings 12a and 12b, and has a roller 121a at one end 121 thereof. Further, the linear motion shaft 12 includes a biasing portion 13 that biases the roller 121a of the one end portion 121 to the cam surface 11a of the outer cam 11 on the other end side. By the urging portion 13, the end 121 of the linear motion shaft 12 is urged to the outer cam 11, so that the roller 121 a comes into contact with the cam surface 11 a.
The roller 121a abuts on the cam surface 11a of the outer peripheral cam 11 and slides along the cam surface 11a according to the rotation of the outer peripheral cam 11. As the roller 121a slides in contact with the cam surface 11a, the linear movement shaft 12 moves in the axial direction thereof and performs a substantially straight linear movement along the axial direction.
Then, the linear motion shaft 12 moves in the direction approaching the lower shaft 2 at the timing when the roller 121a comes into contact with the recessed point of the cam surface 11a of the outer circumferential cam 11. Further, when the roller 121a passes through the recessed point, the linear movement shaft 12 moves away from the lower shaft 2 and returns to the original arrangement.
That is, the linear motion shaft 12 performs linear motion that reciprocates along the axial direction according to the shape of the cam surface 11 a of the outer peripheral cam 11.

The urging portion 13 is a first magnet 13a provided at the other end of the linear motion shaft 12, and a second direction provided in an arrangement in which the repulsive force acts in a direction repelling the first magnet 13a. It has the magnet 13b and the urging | supporting support stand 13c by which the 2nd magnet 13b is arrange | positioned.
When the first magnet 13a is repelled by the second magnet 13b, a biasing force acts on the linear motion shaft 12 on which the first magnet 13a is disposed, and the roller 121a of the one end portion 121 of the linear motion shaft 12 moves. The cam surface 11a is biased. The one end 121 of the linear motion shaft 12 is urged by the outer circumferential cam 11 by the magnetic force of the urging portion 13 so that the roller 121a of the one end 121 is always in contact with the cam surface 11a of the outer circumferential cam 11. It has become.
Thus, since the urging portion 13 urges the one end 121 of the linear motion shaft 12 to the outer peripheral cam 11 by the repulsive force of the magnetic force of the first magnet 13a and the second magnet 13b, deterioration such as wear and breakage is not caused. Since it does not easily occur in the magnet of the urging unit 13, the urging of the linear motion shaft 12 having good durability can be achieved.

  The square piece 14 is fixed to the upper surface of the linear motion shaft 12 with a screw N, and can move along with the linear motion shaft 12 in the axial direction of the linear motion shaft 12 in accordance with the linear motion of the linear motion shaft 12. Is provided.

The arm portion 15 has a proximal end fixed to the opener shaft 16 by a screw N, and a recess 15a into which the square piece 14 is fitted is formed on the distal end side.
The arm portion 15 is configured to switch its arrangement so that the arm portion 15 moves together with the square piece 14 in accordance with the movement of the square piece 14 accompanying the linear movement of the linear movement shaft 12.

  The opener shaft 16 is pivotally supported by the bearings 16a and 16b, and rotates about its axis in accordance with the movement of the arm portion 15 fixed to the opener shaft 16.

The lever portion 17 is fixed to the upper end portion 161 of the opener shaft 16 with a screw N, and swings as the opener shaft 16 rotates according to the movement of the arm portion 15.
In particular, the lever portion 17 swings at a timing when the roller 121a comes into contact with a recessed point of the cam surface 11a and when the linear motion shaft 12 linearly moves in a direction close to the lower shaft 2.
The swinging lever portion 17 comes into contact with the inner hook 4.

  Next, the operation of the opener 100 in the horizontal hook 1 of the sewing machine will be described.

When the sewing machine is driven and sewing is performed, the sewing needle moves up and down, and the upper thread is fed below the needle plate 8 by the sewing needle.
Then, the outer hook 3 is rotated by the hook shaft 7 that rotates with the rotation of the lower shaft 2, and the sword tip 31 of the outer hook 3 catches the upper thread loop formed by the sewing needle. Since the protrusion 41 of the inner hook 4 is loosely fitted to the fitting portion 81 of the needle plate 8, the inner hook 4 is not interlocked with the rotation of the outer hook 3, and the inner hook 4 itself rotates. It is supposed not to.

On the other hand, the outer peripheral cam 11 is also rotated along with the rotation of the lower shaft 2, and a linear motion shaft 12 substantially perpendicular to the lower shaft 2 is disposed on the cam surface 11 a of the outer peripheral cam 11 at one end 121 (roller). 121a).
When the predetermined point where the cam surface 11 a is depressed reaches a position where the one end 121 of the linear motion shaft 12 comes into contact, the linear motion shaft 12 moves in a direction close to the lower shaft 2. That is, the linear movement shaft 12 moves linearly at the timing when the one end portion 121 of the linear movement shaft 12 comes into contact with a predetermined point where the cam surface 11a is recessed.

As the linear movement shaft 12 linearly moves in a direction substantially perpendicular to the lower shaft 2, the arm portion 15 engaged with the square piece 14 fixed to the linear movement shaft 12 is The arrangement is switched by swinging so as to move the concave portion 15a side in an arc shape.
As the arm portion 15 swings, the opener shaft 16 fixed to the base end portion of the arm portion 15 rotates to operate the lever portion 17 fixed to the upper end portion 161 to swing. .

The actuated lever portion 17 abuts against the inner hook 4 to act so as to separate the protrusion 41 of the inner hook 4 from the fitting portion 81 of the needle plate 8, and the protrusion 41 generated at that timing When the upper thread loop passes through the gap of the fitting portion 81, the upper thread and the lower thread are entangled and a seam is formed.
If the position where the one end 121 of the linear motion shaft 12 abuts by the further rotation of the outer circumferential cam 11 is not a depression which is a predetermined point on the cam surface 11a, the linear motion shaft 12 is separated from the lower shaft 2. Returning to the standby position, the protruding portion 41 of the inner hook 4 returns to the restricted state in which it is loosely fitted to the fitting portion 81 of the needle plate 8.

  Thus, each time the lower shaft 2 makes one revolution, the sword tip 31 of the outer hook 3 catches the upper thread loop, and then the lever portion 17 swings as the opener shaft 16 rotates, so that the lever portion 17 The protrusion 41 and the fitting portion 81 are separated from each other by coming into contact with the shuttle 4, and the stitches are repeatedly formed by passing the upper thread loop through the gap, and sewing is performed by the sewing machine.

As described above, the opener 100 of the horizontal hook 1 of the sewing machine has the lever portion 17 at the timing when the one end 121 of the linear motion shaft 12 abuts on the recessed portion formed in one place on the cam surface 11a of the outer peripheral cam 11. By swinging and actuating, the lever portion 17 is brought into contact with the inner hook 4 at a periodic timing synchronized with the vertical movement of the sewing needle, and the protrusion 41 of the inner hook 4 is fitted to the fitting portion 81 of the needle plate 8. Can be pulled away from.
In other words, the lever portion 17 is swung at a predetermined timing in one cycle when the lower shaft 2 rotates once to form one seam, so that the protrusions 41 are fitted in a predetermined cycle for each stitch. The upper thread loop can be passed through the gap by separating the portion 81 from each other, and a good seam can be formed.

In particular, the opener 100 in the horizontal hook 1 of the sewing machine according to the present invention converts the movement of the linear movement shaft 12 that linearly moves once every rotation of the lower shaft 2 into a movement in which the arm portion 15 swings. The lever portion 17 can be operated by rotating the opener shaft 16 based on the swing of the arm portion 15.
The amount of rotation of the opener shaft 16 that operates the lever portion 17 is defined by the amount of swing that is the amount of movement of the arm portion 15, so that the amount of rotation of the opener shaft 16 that allows the lever portion 17 to operate properly is obtained. Therefore, the length and shape of the arm portion 15 may be designed so as to adjust the swing radius of the arm portion 15.

As described above, the horizontal hook 1 of the sewing machine according to the present invention makes it possible to adjust the amount of rotation of the opener shaft 16 according to the swing radius of the arm portion 15, and the lever by the preferable rotation of the opener shaft 16. Since the opener 100 for properly operating the portion 17 is provided, it is necessary to make the distance between the opener shaft 16 and the lower shaft 2 (the shuttle shaft 7) long, or conversely, on the design of the sewing machine. Even if it does not happen, it is not necessary to change the design of the shape of the cam surface 11a so that the amount of displacement by the outer peripheral cam 11 is increased or decreased.
That is, in order to operate the opener 100 appropriately, it is only necessary to provide the outer peripheral cam 11 having the shape of the cam surface 11a capable of stably reciprocating the linear motion shaft 12.
By changing the design of adjusting the swing radius of the arm portion 15 so as to obtain the amount of rotation of the opener shaft 16 that can operate the lever portion 17 as desired, various types of sewing machines and It is possible to design an opener that easily corresponds to the horizontal hook of the sewing machine.

  As described above, in the horizontal shuttle 1 of the sewing machine, the outer peripheral cam 11 capable of stably reciprocating the linear motion shaft 12 and the linear motion shaft 12 reciprocating (direct motion) are interlocked with each other and proper swinging is performed. As a result of the provision of the opener 100 that operates the lever portion 17 as desired, the sewing product quality in the sewing machine can be improved.

The present invention is not limited to the above embodiment.
For example, as shown in FIGS. 5A and 5B, the opener of the horizontal hook 1 of the sewing machine includes a linear motion shaft 120 having a rack portion 120a as an engaged portion formed on a side surface, and the rack A structure in which a pinion gear 18 as an engaging portion having a pinion portion 18 a meshing with the portion 120 a is attached to the opener shaft 16 may be used.
Even in the horizontal hook 1 of the sewing machine having the opener having such a structure, the lever portion 17 is preferably adjusted by adjusting the rotation amount of the opener shaft 16 in accordance with the design change for adjusting the rotation radius of the pinion gear 18. Can be activated.
A good seam can be formed by separating the protrusion 41 and the fitting portion 81 at a predetermined cycle for each stitch and passing the upper thread loop through the gap, thereby improving the quality of the sewing product. It becomes possible.

  In the above embodiment, the urging unit 13 has been described by taking as an example the repulsive force of a pair of magnets. However, the present invention is not limited to this, and for example, a spring or The structure may be such that the linear motion shaft 12 is urged toward the outer cam 11 by an elastic member such as rubber. At this time, one end of the spring as the urging portion is supported by the sewing machine frame, and the other end urges the other end of the linear motion shaft 12. By this urging, the roller 121a attached to the linear motion shaft is always in contact with the cam surface 11a of the outer peripheral cam 11.

  Moreover, in the above embodiment, although the example which reciprocates (directly moves) the linear motion shaft 12 using the outer peripheral cam 11 which has the hollow of one place in the cam surface 11a was demonstrated, this invention was demonstrated. However, the present invention is not limited to this. For example, the linear motion shaft may be linearly moved using an outer peripheral cam having a single convex portion on the cam surface.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

It is a disassembled perspective view which shows the horizontal shuttle of the sewing machine which concerns on this invention. It is a side view which shows the horizontal shuttle of the sewing machine which concerns on this invention in partial cross section. FIG. 3 is a top view showing a horizontal hook of the sewing machine as viewed from the direction of arrow III in FIG. FIG. 4 is a bottom view showing the horizontal hook of the sewing machine as viewed from the direction of arrow IV in FIG. 2. It is explanatory drawing which shows the modification of the engaging part and engaged part of an opener, and is the exploded perspective view (A) and the bottom view (B).

Explanation of symbols

1 Horizontal hook of sewing machine 2 Lower shaft (sewing lower shaft)
DESCRIPTION OF SYMBOLS 3 Outer hook 31 Blade tip 4 Middle hook 41 Projection part 5 First bevel gear 6 Second bevel gear 7 Hook shaft 8 Needle plate 81 Fitting part 100 Opener 11 Outer peripheral cam 11a Cam surface 12 Direct acting shaft 13 Energizing part 13a First Magnet 13b Second magnet 13c Energizing support base 14 Square piece (engaged part)
15 Arm (engagement part)
15a Concave portion 16 Opener shaft (rotating shaft)
17 Lever part 18 Pinion gear (engagement part)
18a Pinion part 120 Linear motion shaft 120a Rack part (engaged part)

Claims (3)

An outer hook having a sword tip for capturing an upper thread loop formed by a sewing needle;
A lower shaft of a sewing machine for rotating the outer hook;
An inner hook that is disposed within the outer hook and has a protrusion that is loosely fitted into a predetermined fitting portion;
An opener that periodically separates the protrusion and the fitting portion in synchronization with the vertical movement of the sewing needle and passes the upper thread loop through the gap;
The opener
An outer peripheral cam fixed to the sewing machine lower shaft;
A linear motion shaft whose one end is in contact with the cam surface of the outer peripheral cam and movable in the axial direction;
An urging portion that is provided on the other end side of the linear movement shaft and urges the one end portion toward the cam surface;
An engaged portion provided on the linear motion shaft;
A rotating shaft that has an engaging portion that engages with the engaged portion, and that rotates around the axis according to the movement of the engaging portion that accompanies the linear movement of the linear movement shaft;
A horizontal hook for a sewing machine, comprising: a lever portion that comes into contact with the inner hook as the rotary shaft rotates.   The horizontal hook of the sewing machine according to claim 1, wherein the engaged portion is a square piece, and the engaging portion is an arm portion having a concave portion engaged with the square piece. The urging portion has a first magnet provided at the other end of the linear movement shaft, and a second magnet arranged to repel the first magnet,
3. The horizontal hook of the sewing machine according to claim 1, wherein the first magnet is repelled by the second magnet, whereby one end portion of the linear motion shaft is biased to the cam surface. 4.

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