JPH08299637A - Presser arm releasing mechanism for sewing machine - Google Patents

Abstract

PURPOSE: To manually release a fabric presser by making the pressing force to a presser arm releasable via the coupling with a pressing means when an operation lever is operated, and making an upper feed dog liftable via the coupling with the upper feed mechanism of a lifting member assembled coaxially with the operation lever. CONSTITUTION: When a pressing/lifting lever 2 is pressed backward and downward around a shaft 7 against a spring for the various work such as the thread insertion into a needle or the resolution of a sewing jam, the lifting tip section 8 of the lever 2 lifts a lifting pin 21 from below, and a presser bar 20 is lifted against a spring. The pressing force to the front section of a presser arm 16 by a forked section at the lower section of the presser bar 20 is released. A lifter 3 on the shaft 7 is rotated CCW, a lifting pin 9 lifts a lifting projection from below, a piece is lifted against a spring, a rocking lever 26 coupled with the piece is lifted, and an upper feed dog 27 is released from a fabric presser and is located at the lifted position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overlock sewing machine of a type in which an upper feed dog cooperating with a lower feed tooth is arranged in a through hole of the work clamp so as to release a presser arm for avoiding a side of the work clamp. It is related to the mechanism.

[0002]

2. Description of the Related Art In an overlock sewing machine, a cloth presser is generally attached to a free end of a vertically rotatable presser arm whose base is connected to a presser lifting shaft through a crank. During various operations such as threading, eliminating thread jams, removing the needle plate for repair, cleaning, and adjusting the looper, release the spring pressure that acts on the presser arm, and then turn the work clamp sideways with the presser arm. By doing so, it is avoided from the stitch forming area so that the work clamp does not hinder the above-mentioned various operations. However, in an overlock sewing machine of the type in which an upper feed mechanism that cooperates with the lower feed mechanism is provided, and the upper feed dog is arranged in the through hole of the presser foot, the upper feed tooth interferes with the side presser foot. I can't avoid it. Therefore, for example, by pressing the presser bar lifting lever to raise the presser bar, the spring pressure acting on the presser arm is released, and further, by stepping on the foot lever to raise the upper feed dog, the presser arm and the cloth presser foot are pressed. Was canceled, that is, side avoidance could be performed.

As described above, when the presser arm is released, the force transmission system for pulling up the presser bar is different from the force transmission system for raising the upper feed dog, that is, the former manually pushes in the presser bar lifting lever. However, the latter requires stepping on the stepping lever, and two systems of operations must be performed, which is troublesome. Therefore, it is possible to release the presser foot (side avoidance) by one operation.
It is known from 127098 and Japanese Patent Laid-Open No. 5-3918.

First, in the one disclosed in Japanese Patent Laid-Open No. 127098/1987, the spring pressure acting on the presser arm is released by operating the operating lever, and the upper feed dog is placed on the presser foot (presser foot). The operation lever 28 is provided with a hook portion 31 for pushing up the pin 32 for releasing the spring pressure acting on the presser arm (presser base) 5, if the reference numerals in the drawings of the publication are also shown. , In order to lift the upper feed dog 22, between the operating lever 28 and the upper feed base 18,
A mechanism including a link 25, a horizontal shaft 14, an arm 15 and a roller 16, a leaf spring 11, a lever 9 and a roller 17 is provided. In addition to the one disclosed in Japanese Patent Laid-Open No. 62-127098, the one disclosed in Japanese Laid-Open Patent Publication No. 5-3918 makes it possible to operate smoothly. If written together, the operation lever 3
8 is provided with a cam portion 39 for pushing up the pin 35 for releasing the spring pressure acting on the presser arm (holding base) 8, and in order to lift the upper feed dog 3, the operation lever 38 and the upper feed base 2 are combined. In the meantime, the link 44, the lever 43, the operating shaft 42,
A mechanism including a claw lever 45, an arm 28, a lifting lever 27, etc. is provided.

[0005]

As described above, the conventional one in which the release of the presser foot (presser foot) (side avoidance) can be performed by one operation with the operation lever is required to lift the upper feed dog. It required a lot of parts. That is, in the one disclosed in JP-A-62-127098, the link 25, the horizontal shaft 14, the arm 15 and the roller 16, the leaf spring 11, the lever 9 and the roller 17 and other multi-components are mounted on the operation lever 28 and The link 4 is provided between the feed table 18 and the one disclosed in Japanese Patent Laid-Open No. 5-3918.
4, lever 43, operating shaft 42, claw lever 45, arm 2
8 and lifting lever 27
And the upper feed table 2 were interposed. Thus, conventionally, in an overlock sewing machine of the type in which the upper feed dog is arranged in the through hole of the presser foot (presser foot), the pin for releasing the spring pressure acting on the presser arm (presser base) is pushed up. In addition to providing hooks and cams on the operating lever, many parts are required to lift the upper feed dog, which is costly and the assembly of these many parts on the sewing machine body is complicated. However, there was a problem that the maintenance was troublesome.

Therefore, an object of the present invention is to enable an overlock sewing machine of the type in which the upper feed dog is disposed in the through hole of the presser foot to release the presser foot (side avoidance) by one operation of the operating lever. Of course, in addition to providing the operation lever with a part that pushes up the pin for releasing the spring pressure that acts on the presser arm, minimize the parts for lifting the upper feed dog, and unitize it including the operation lever. Accordingly, it is an object of the present invention to provide a presser arm release mechanism for a sewing machine, which achieves cost reduction, easy assembly to the sewing machine main body, and easy maintenance.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a presser foot attached to a presser arm that is rotatable in the up-and-down direction, and a pressing means for pressing down the presser arm.
A presser arm release mechanism for a sewing machine, which is located in a through hole of the cloth presser and has an upper feed tooth for feeding the cloth. The presser arm release mechanism engages with the presser down means and presses down the presser arm. And a push-up member that is mounted coaxially with the operation lever and that engages with the upper feed mechanism to raise the upper feed dog, and the work clamp and upper feed are operated by operating the operation lever. The feature is that the teeth are raised.

[0008]

According to the present invention, the work clamp attached to the presser arm is coaxial with the operating lever for engaging the press-down means for pressing down the presser arm that can rotate in the vertical direction and releasing the press-down force to the presser arm. Since this is a presser arm release mechanism that is assembled with a push-up member that engages with the upper feed mechanism having the upper feed tooth located in the through hole and raises the upper feed tooth, this operating lever becomes the pushing down means by operating the operating lever. Engage to release the pushing down force on the presser arm,
The push-up member assembled coaxially with the operation lever,
By engaging with the upper feed mechanism and raising the upper feed dog, it becomes possible to manually release the presser foot (side avoidance). Moreover, since the push-up member is assembled coaxially with the operation lever, the push-up member including the operation lever can be unitized, and the number of parts for lifting the upper feed dog can be minimized, thereby reducing the cost and the sewing machine. Assembling to the main body becomes easy and maintenance becomes easy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a presser arm release mechanism for a sewing machine according to the present invention will be described below with reference to FIGS. First, FIG. 1 is an exploded perspective view of a unit part constituting a presser arm release mechanism as an example to which the present invention is applied, and FIG.
Is a perspective view of a unit state, FIG. 2 (b) is a side view showing a lever spring portion, and FIG. 2 (c) is a front view showing an incorporated portion of a pushing-up member. In these FIG. 1 and FIG.
1 is a main mounting plate, 1a is a long hole, 2 is an operating lever (presser lifting lever), 2a is an engaging pin, 3 is a lifting member (lifter), 4 is a sub mounting plate, 5 is a lever spring, 6 is a stopper plate, Reference numeral 7 is a lever shaft, 8 is a push-up tip portion, and 9 is a push-up pin.

As shown in the figure, a main attachment plate 1 is provided with a presser foot lifting lever 2 which is an operation lever for releasing a presser arm, which will be described later.
A lifter 3, which is a push-up member for pushing up a swing rod, a sub-mounting plate 4, a lever spring 5, and a stopper plate 6, which will be described later.
Is assembled. That is, the lever shaft 7 integrated with the lower part of the presser foot lifting lever 2 is passed through the L-shaped main mounting plate 1 in plan view, and the lever shaft 7 under the presser foot lifting lever 2 is inserted.
A push-up tip portion 8 is formed so as to be pushed up to the tip side from the portion. Then, the lifter 3 is fixed on the lever shaft 7 by split tightening and screwing, and the lever shaft 7 is fixed to the lifter 3.
It is provided with a push-up pin 9 parallel to.

Further, the tip of the lever shaft 7 is supported by a sub-mounting plate 4 which is L-shaped in a plan view, and the sub-mounting plate 4 is fixed to the main mounting plate 1 by screws. Here, as indicated by an arrow in FIG. 2C, the lifter 3 is attached between the main mounting plate 1 and the sub mounting plate 4 with a gap that does not result in a resistance torque. Further, a lever spring 5 made of a torsion coil spring is mounted on the protruding end portion of the lever shaft 7 on the other surface side of the presser lifting lever 2, and a stopper plate 6 is fixed to the main mounting plate 1 by screwing. The lever spring 5 is located between the stopper plate 6 and the main mounting plate 1 as shown by the arrow in FIG.
In the lever spring 5, one end is hooked on the engagement pin 2a provided on the presser foot lifting lever 2 and the other end is abutted against the stopper plate 6, so that the presser lift lever 2 is rotated clockwise in the figure around the lever shaft 7. To urge Further, the engagement pin 2a is engaged with the elongated hole 1a formed in the main mounting plate 1.

As described below, the presser arm releasing mechanism in which the presser bar lifting lever 2 and the lifter 3 are unitized as described above may be mounted on the sewing machine main body by screwing the main mounting plate 1 as described later. FIG. 3 shows the sewing machine main body before attachment of the presser arm release mechanism, and is a side view showing the cloth pressing mechanism and the upper feed mechanism. FIG. 4 (a) is a side view showing the cloth pressing mechanism, and FIG. 4C is a side view showing the upper feed mechanism, and FIG. 4C is a sectional view taken along the line ZZ of FIG. 4B. 3 and 4, 10 is a sewing machine main body, 11 is a main shaft, 12 is a presser foot mechanism, 13 is a presser foot lifting shaft, 14 is a crank, 15 is a vertical pin, 16 is a presser arm, 17 is a presser foot, and 18 is a presser foot. Is a pushing-down means, 19 is a metal, 20 is a presser bar, 21 is a push-up pin, 22 is an upper feed mechanism, 23 is a longitudinal feed shaft, 24 is a crank, 25 is a pivot pin, 26 is a swing rod, and 27 is an upper feed. Teeth, 28 vertical feed shafts, 29 cranks, 30 pivot pins, 31 tops, 3
2 is a push-up protrusion.

As shown in the figure, the sewing machine body 10 of the overlock sewing machine has a main shaft 11 and a lower feed mechanism (not shown) which is interlocked with the rotation of the main shaft 11 in the lower part, and is interlocked by depressing a foot lever (not shown) in the upper part. The cloth feed mechanism 12 and the upper feed mechanism 22 that cooperates with the lower feed mechanism in association with the rotation of the main shaft 11 are provided. As shown in FIG. 4 (a), the work clamp mechanism 12 includes the presser foot lifting shaft 1
The presser arm 16 is connected to the crank 14 fixed to the end portion of 3 through the vertical pin 15, and the presser arm 17 is provided at the front end portion of the presser arm 16. The presser foot lifting shaft 13 is rotated in the counterclockwise direction in the drawing in conjunction with the stepping of the foot stepping lever (not shown). When the foot stepping lever is not stepped on, the presser foot 17 has the needle plate as shown in the figure. Located on top. Further, the presser arm 16 is rotatable around the vertical pin 15 with respect to the rear crank 14.

In the above-described cloth pressing mechanism 12, the pressing arm 1
Depressing means 18 is provided for holding 6 in the illustrated depressed state. The pushing-down means 18 has a metal 19 fixed to the sewing machine body 10 in which a pressing rod 20 protruding downward and a spring (not shown) for urging the pressing rod 20 in a downward protruding direction are incorporated. . Presser bar 2
In the case of 0, the lower part has a bifurcated shape and is pressed down so as to sandwich the front part of the presser arm 16 (see FIG. 6B). And
A push-up pin 21 protruding upward from the presser arm 16 is provided on one side of the presser bar 20, and the push-down pin 21 projects outside from a slit of the metal 19 (FIG. 6B). reference).

As shown in FIG. 4 (b), the upper feed mechanism 22 includes the crank 2 fixed to the end of the front-rear feed shaft 23.
4, a swing rod 26 is connected via a pivot pin 25, and an upper feed dog 27 is provided at the front end portion of the swing rod 26. As shown in FIG. 4C, the upper feed dog 27 is located in the through hole of the presser foot 17. further,
The swing rod 26 has a top 31 connected to a crank 29 fixed to an end of the vertical feed shaft 28 via a pivot pin 30.
Are engaged. Then, as shown in FIG. 6A, a push-up protrusion 32 is integrally formed on the top 31. Further, a push-down spring 33 for urging the top 31 in the pushing-down direction is provided.

The front-rear feed shaft 23 swings around the shaft in conjunction with the rotation of the main shaft 11 to generate the crank 2
4, the upper feed dog 27 is reciprocated in the front-back direction via the pivot pin 25 and the swing rod 26. Further, the vertical feed shaft 28 swings around the shaft center in association with the rotation of the main shaft 11,
The swing rod 2 through the crank 29, the pivot pin 30, and the top 31.
6 is reciprocated in the vertical direction, that is, the upper feed dog 27 is reciprocated in the vertical direction. Therefore, the upper feed dog 27 reciprocates in the front-rear direction due to the rotation from the front-rear feed shaft 23,
By performing a combined motion of the vertical reciprocating motion due to the rotation from the vertical feed shaft 28, the cloth feed is performed in cooperation with the lower feed dog (not shown).

On the side surface of the sewing machine body 10 having the above-described presser foot mechanism 12 and upper feed mechanism 22, the main attachment plate 1 of the presser arm release mechanism, which is a unitized structure of the above-mentioned presser foot lifting lever 2 and lifter 3, is provided. Attach by screwing. FIG. 5 shows a state in which the presser arm releasing mechanism in which the presser foot lifting lever 2 and the lifter 3 are unitized in this way is attached to the side surface of the sewing machine main body 10. here,
The push-up pin 9 of the lifter 3 and the push-up protrusion 32 of the top 31 are in a positional relationship of vertically overlapping with each other, as indicated by an arrow in FIG. Further, the push-up tip portion 8 of the presser-lifting lever 2 and the push-up pin 21 of the presser bar 20 are also in a vertically overlapping positional relationship as shown in FIG. 6B.

Since the overlock sewing machine is provided with the presser arm releasing mechanism having the above structure, for example, threading the needle,
The presser foot lifting lever 2 is used for various operations such as removing jams, repairs by removing the needle plate, cleaning, and adjusting the looper.
Against the urging force of the lever spring 5 and pushes the lever downward around the lever shaft 7. Then, as shown in FIGS. 7 (a) to 7 (b), the push-up tip end portion 8 of the presser foot pull-up lever 2 rotating counterclockwise around the lever shaft 7 pushes up the push-up pin 21 from below. Since the presser bar 20 is pushed up against the urging force of the spring (not shown), the pressing down force of the forked part at the lower part of the presser bar 20 on the front part of the presser arm 16 is released.

At the same time, the lifter 3 on the lever shaft 7 also rotates counterclockwise as shown in FIGS. 8 (a) to 8 (b), so that the push-up pin 9 of the lifter 3 pushes up the protrusion. 32 is pushed up from below, and as shown in FIG.
As shown in (b), the top 31 is pushed down by the pressing spring 3
Since it is pushed up against the urging force of 3, the swing rod 26 with which the top 31 is engaged is pushed up with the pivot pin 25 at the rear part as a fulcrum. Therefore, the upper feed dog 27 provided at the front end portion of the swing rod 26 is pushed up to the position where the upper feed dog 27 is disengaged from the through hole of the presser foot 17 and is raised as shown in FIG. 8C.

FIG. 10 shows a state in which the presser arm 16 and the presser foot 17 are released from the restraint in this way and are free. As described above, when the presser arm 16 and the presser foot 17 are released from the restraint and are in the free state, the presser arm 16 or the presser foot 17 is held and the presser arm 16 is laterally moved around the vertical pin 15 at the rear portion. By pivoting to, as shown in FIG. 11, the presser arm 16 and the cloth presser 17 can be brought into a sideward avoidance state.

As described above, according to the presser arm releasing mechanism of the present invention, the presser bar 20 and the upper feed dog 27 can be simultaneously raised by pressing the presser bar lifting lever 2. In addition, the presser arm release mechanism of the present invention can contribute to cost reduction because the presser foot lifting lever 2 and the lifter 3 are unitized and configured with the minimum number of parts, and the unit can be easily attached to the sewing machine main body 10. Also, maintenance work such as repair and inspection can be easily performed.

In the above embodiments, the push-up member that engages with the top assembled to the swing rod is used. However, the present invention is not limited to this, and the push-up member that directly engages the swing rod is used. It may be a member. Also, the shape of the presser foot lifting lever and the lifting member is arbitrary, and
It goes without saying that the specific detailed structure and the like can be changed as appropriate.

[0023]

As described above, according to the presser arm releasing mechanism of the sewing machine of the present invention, the pressing force for the presser arm can be released by the engagement with the pressing means by operating the operating lever, and Since the upper feed dog can be raised by the engagement with the upper feed mechanism of the push-up member assembled coaxially, the release of the presser foot (side avoidance) can be performed manually. In addition, since the push-up member is assembled coaxially with the operation lever, the component for lifting the upper feed dog can be unitized with the push-up member including the operation lever with the minimum of one component by the push-up member. In addition to cost reduction, the operating lever and the pushing-up member can be easily assembled as a unit with respect to the sewing machine main body, and maintenance can be easily performed.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a unit part constituting a presser arm release mechanism as an example to which the present invention is applied.

2A and 2B show the presser arm releasing mechanism of FIG. 1, in which FIG. 2A is a perspective view of a unit state, FIG. 2B is a side view showing a lever spring portion, and FIG. 2C is a front view showing an assembled portion of a lifting member. It is a figure.

FIG. 3 is a side view showing a sewing machine main body before attachment of a presser arm release mechanism, showing a cloth presser mechanism and an upper feed mechanism.

FIG. 4 is a view showing the mechanism of FIG. 3 separately, in which (a) is a side view showing a cloth pressing mechanism, (b) is a side view showing an upper feeding mechanism, and (c) is a side view of (b). It is sectional drawing which followed the arrow ZZ line.

5 is a side view showing a state in which a presser arm release mechanism is attached to the sewing machine main body of FIG.

FIG. 6 is a partially cutaway front view showing the relationship between the presser arm release mechanism, the presser arm pressing means, and the upper feed mechanism, and FIG.
(B) is a partially broken front view showing the relationship between the operation lever and the pushing means.

FIG. 7 shows a state before and after pushing the operation lever by omitting the upper feed mechanism, (a) is a side view showing a state before pushing the operation lever, and (b) is a state after pushing the operation lever. It is a side view showing the state.

8A and 8B show a state before and after the operation lever is pushed in without a presser foot mechanism, where FIG. 8A is a side view showing a state before the operation lever is pushed in, and FIG. 8B is a side view after pushing the operation lever. Side view showing the state of (b), (c) is an arrow Z of (b)
It is a sectional view taken along the line Z.

FIG. 9 shows the relationship between the presser arm release mechanism and the presser arm depressing means as a state corresponding to the state before and after the operation lever is pushed. (A) is a partially broken view showing the state before the operation lever is pushed. The front view, (b) is a partially broken front view showing a state after the operation lever is pushed.

FIG. 10 is a side view showing a state in which the presser arm is released and the state of the presser foot mechanism, the upper feed mechanism and the presser arm release mechanism of the sewing machine main body.

FIG. 11 is a perspective view showing a state in which the presser arm and the presser foot are avoided by turning sideways.

[Explanation of symbols]

 1 Main Mounting Plate 2 Operation Lever (Presser Lifting Lever) 3 Push Up Member (Lifter) 4 Sub Mounting Plate 5 Lever Spring 6 Stopper Plate 7 Lever Shaft 8 Push Up Tip 9 Push Up Pin 10 Sewing Machine Main Body 11 Spindle 12 Cloth Pressing Mechanism 13 Presser Lifting Shaft 14 crank 15 vertical pin 16 presser arm 17 cloth presser 18 push-down means 19 metal 20 presser bar 21 push-up pin 22 upper feed mechanism 23 longitudinal feed shaft 24 crank 25 pivot pin 26 swinging rod 27 upper feed tooth 28 upper feed shaft 29 crank 30 Pivot pin 31 Top 32 Push-up protrusion 33 Push-down spring

Claims (1)

[Claims] 1. A presser foot attached to a vertically movable presser arm, a pressing means for pressing down the presser arm, and an upper feed dog positioned in the through hole of the presser foot for feeding the cloth. A presser arm release mechanism of a sewing machine including an upper feed mechanism, wherein an operation lever that engages with the press-down means to release the pressing force against the presser arm, and is assembled coaxially with the operation lever, A presser arm releasing mechanism for a sewing machine, comprising: a push-up member that engages with a mechanism to raise the upper feed dog, and raises the cloth presser and the upper feed tooth by operating an operation lever.