JPH0120631B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a sewing machine, and in particular, a guide rod fixed to a machine frame guides the raising and lowering of a needle, and a cylindrical lower hollow part of the guide rod guides the raising and lowering of a presser foot. By guiding, the needle and the presser foot are guided by the same guide rod, achieving structural simplicity and cost and weight reduction.

In conventional sewing machines, a needle is attached to the lower end of a needle bar that moves up and down, and a presser foot is attached to the lower end of a presser foot guide bar that extends roughly parallel to the needle bar and moves up and down independently of the needle bar. In fact, two rods extending vertically were exposed to the upper surface of the throat plate where the sewing work was performed.
Therefore, the structure has not only become complicated, but also has an unsatisfactory appearance, and is also a cause of high costs. In addition, the weight is large, which hinders efforts to reduce the weight of portable sewing machines.

Therefore, this invention was made to solve these problems, and its purpose is to simplify the structure, and its purpose is to reduce cost and weight. The purpose is to improve aesthetic appearance.

In this application, as in the illustrated embodiment, a needle holder 4 holding a needle 3 is slidably engaged with a guide rod 2 fixed to a machine frame 1, and the needle holder 4 is
The guide rod 2 is connected to an actuating arm 5 that reciprocates, and has at least a cylindrical lower portion and a hollow portion 6 thereof.
A presser bar 8 supporting a presser foot 7 is slidably inserted into the lower side, and a presser spring 9 is engaged with the presser bar 8 to bias it downward. In addition to making the sewing machine a specified invention, a needle holder 4 holding a needle 3 is slidably engaged with a guide rod 2 fixed to a machine frame 1, and the needle holder 4 is connected to an operating arm 5 that reciprocates. At least the lower part of the guide rod 2 is made into a cylindrical shape, and a presser bar 8 supporting a presser foot 7 on the lower side is slidably inserted into the hollow part 6 of the guide rod 2,
A presser spring 9 that urges the presser bar 8 downward is engaged with the presser bar 8, and the actuating arm 5
, an upper knife operating body 1 carrying an upper knife 10 on the lower side.
1 are connected, and the upper knife operating body 11 is slidably engaged with the guide rod 2 to guide the upper knife 10, needle 3, and presser foot 7 by the guide rod 2, and the upper knife A sewing machine characterized in that the needle 10 and the needle 3 are configured to be interlocked by the actuating arm 5 is provided as a combined invention.

The present invention will be described below with reference to an illustrated embodiment applied to a portable overedge sewing machine.

At the top of the machine frame 1 forming the bracket arm,
A guide rod fixing body 13 with a boss 12 formed thereon, into which a cylindrical guide rod 2 is press-fitted and fixed, is fixed with a bolt 14, so that the axis of the guide rod 2 can be slightly adjusted. A threaded groove 15 is provided on the inner circumference of the upper part of the guide rod 2.
A spring adjustment screw 17 having a knob 16 at the upper end is screwed into the thread groove 15.
A presser bar 8 having a presser foot 7 fixed to its lower end with a bolt 18 for pressing the cloth is inserted into the hollow portion 6 at the bottom of the guide rod 2 so as to be slidable in the axial direction. Presser bar 8
A pin 19 is provided protruding in the middle of the
is a presser foot lifting lever which is pivotably pivoted to the machine frame 1 and projects outward from an elongated hole 2a formed in the guide rod 2 and an elongated hole 42 formed in a cylindrical portion 38 of the upper knife operating body 11, which will be described later. The tip of pin 20 faces the bottom surface of pin 19. The presser foot lifting lever 20 is pivotally mounted by a bolt 21, and a torsion coil spring 22 biases the tip of the lever 20 in the downward direction, while a stopper 23 is formed in the machine frame 1 through which the rear part of the lever 20 passes. do. As shown in FIG. 5, the stopper 23 consists of a step formed in the middle of a vertically elongated hole 24 that is wide at the bottom and narrow at the top.
By engaging the presser foot lifting lever 20, the lowering of the tip of the lever 20 is stopped.
The presser foot lifting lever 20 has elasticity toward the right in FIG. 5, and by pressing it toward the left against the rightward elasticity, the lever 20 is released from the stopper 23. Presser bar 8 and spring adjustment screw 17
A coil spring-like presser spring 9 is installed in the hollow part 6 of the guide rod 2 between the guide rod 2 and the presser rod 8 to urge the presser rod 8 downward. Press the cloth between the presser foot 7 and the presser foot 7.

5 in the figure is a swinging operating arm, which includes a short arm piece 26 and a long arm piece 27 parallel to this.
and a connecting piece 28 that connects these base ends to each other, and the entire body is press-molded into an integral U-shape. A pivot 28a is attached concentrically to both arm pieces 26, 27, and the operating arm 5 is slidably supported on the machine frame 1 by the pivot 28a. Arm piece 26
The upper end of a drive arm 29 that extends in the vertical direction and moves back and forth is pivotally attached to the tip of the drive arm 29, and the lower end of the drive arm 29 is connected to a drive shaft 3 that is rotated by a drive source such as a motor.
0 by holding a cam 31 fixed to the drive shaft 30. Further, a weight 32 is attached to the connecting piece 28 to maintain balance in order to smooth the swinging motion of the operating arm 5. In the middle of the arm piece 27, the lower end is connected to an upper knife actuating body 11, which will be described later.
The upper end of the swinging piece 33, which is pivotally attached to the shaft 34, is pivotally attached to the upper end of the swinging piece 33. The shaft 34 spans both arm pieces 26 and 27, and on the arm piece 26 side, the drive arm 2
9 and the arm piece 26. Arm piece 27
The upper end of a swinging piece 35, the lower end of which is pivotally connected to a needle holder 4 to be described later, is pivotally attached to the tip of the needle holder 4.

The upper knife actuating body 11 has an upper part 36 that is connected to the swinging piece 33.
The upper knife 10 is supported by a lower part 39 integral with the upper part 36, and a cylindrical part 38 is fixed with a bolt 40 in the middle thereof. The cylindrical portion 38 is slidably fitted onto the lower half of the guide rod 2 and is configured to guide the entire upper knife operating body 11 along the guide rod 2. The upper knife 10 supported by the bolt 41 on the lower part 39 has a cross section L.
form a letter shape. Reference numeral 42 denotes an elongated hole formed in the cylindrical portion 38 to avoid interference of the cylindrical portion 38 with the pin 19. The elongated hole 2a formed in the guide rod 2 and the cylindrical portion 38 of the upper knife actuating body 11
By penetrating and engaging the pins 19 in the elongated holes 42 formed in the respective holes, the presser foot 7 and the upper knife 10
prevents the guide rod 2 from rotating in a direction intersecting the axis thereof.

Reference numeral 4 denotes a needle holder, which includes a cylindrical part 43 that fits onto the middle part of the guide bar 2 and slides thereon, a needle bar holder 44 that is integrated with this, and an upper end that is held by the needle bar holder 44. , a needle bar 46 fixed with a bolt 45, and a needle attachment part 47 at the lower end of the needle bar 46.
Attach the upper end of needle 3 to 7. Such a needle holder 4,
It is pivotally connected to the lower end of the swing piece 35 by a pin 48. In addition, the cloth feed device required for the hem sewing machine,
The lower knife, looper, transmission device for driving these, throat plate, thread tension device, etc. are not shown.

Next, the effect will be explained.

When the drive shaft 30 rotates, the drive arm 29 moves up and down by the action of the cam 31, causing the actuation arm 5 to swing up and down about the pivot shaft 28a. The pivot 28a that supports the operating arm 5 is connected to the connecting piece 28.
Although it is biased to the side, the actuating arm 5 is connected to the weight 32.
This maintains balance and allows for smooth rocking. This swinging of the operating arm 5 moves the needle holder 4 and the upper knife operating body 11 up and down along the guide rod 2.

The needle holder 4 is raised and lowered by a swinging piece 35 that moves up and down while swinging as the operating arm 5 swings, and this elevation is guided along the outer peripheral surface of the guide rod 2. That is, the cylindrical portion 43 is guided by the guide rod 2, and the needle bar holding portion 44 is integrated therewith.
The needle bar 46 and needle mounting portion 47 fixed thereto are raised and lowered. Therefore, the needles 3 held by the needle holder 4 move up and down in unison, and work together with a looper (not shown) to perform overlock stitching.

In addition, the upper knife actuating body 11 is configured such that the lifting force generated by the swinging of the actuating arm 5 is applied to the pin 34, the swinging piece 33,
It is transmitted via the pin 37 and moves up and down, and is guided by the guide rod 2 in the cylindrical portion 38 thereof. Therefore, the upper knife 10 carried on its lower part 39
moves up and down together with the upper knife operating body 11, and cuts the edge of the fabric by engaging with the lower knife (not shown). The swinging piece 33 is closer to the arm piece 2 than the swinging piece 35.
7, the vertical stroke of the upper knife 10 is smaller than the vertical stroke of the needle 3. Since both the needle 3 and the upper knife 10 are guided by the same guide rod 2, their vertical loci are parallel to each other.

The presser foot 7 is biased downward by a presser spring 9 that is compressed between the presser bar 8 and the spring adjustment screw 17, so that the presser foot 7 presses the cloth between it and the bed surface 25. Then, due to the change in the thickness of the cloth, the pressing spring 9
It moves up and down while expanding and contracting, absorbing changes in the thickness of the cloth. When releasing the presser foot 7 from the bed surface 25,
By pushing down the rear end of the presser foot lifting lever 20, the tip of the lever 20 is engaged with the lower side of the pin 19, and the tip of the lever 20 pushes up the pin 19. When the pin 19 is pushed up, the presser bar 8 is pushed up while compressing the presser spring 9, and therefore,
The presser foot 7 also rises together and leaves the bed surface 25. When the rear end of the presser foot lifting lever 20 reaches the bottom dead center, its own elasticity causes it to move as shown in FIG.
Engages with the stepped portion of the elongated hole 24 formed in the machine frame 1,
The vertical movement of the presser foot lifting lever 20 is stopped, and the pin 19, presser foot bar 8, and presser foot 7 are held at the top dead center. When lowering the presser foot 7, the rear end of the presser foot lifting lever 20 is moved to the left in FIG. When the force of the hand supporting the presser foot lifting lever 20 is relaxed, the presser foot 7, presser bar 8, and pin 19 are lowered together by the urging force of the presser spring 9, and the presser foot 7 is lowered. The bed surface 25 is urged again.

In this embodiment, the needle holder 4 is guided by the outer surface of the guide rod 2, but it may be guided by the inner surface of the guide rod 2.

FIG. 9 shows an example in which the upper knife 10 has a different shape, which has a rectangular cross section and is bent midway in the vertical direction. The other configurations and operations are the same as in the previous embodiment.

As described above, according to the present invention, a needle holder holding a needle is slidably engaged with a guide rod fixed to a machine frame, and the needle holder is connected to an actuating arm that reciprocates. , at least the lower part of the guide rod is made into a cylindrical shape, and the presser foot supporting the presser foot on the lower side is slidably inserted into the hollow portion of the guide rod, so that the needle and the presser foot are guided by one guide rod. can do. Therefore, the structure is simplified, which contributes to reducing the cost and weight of the sewing machine, and also has the effect of making the sewing machine smaller and improving its aesthetic appearance. and,
Furthermore, if an upper knife operating body carrying an upper knife on the lower side is connected to the operating arm, and this upper knife operating body is slidably engaged with the guide rod, the upper knife, the needle, and the presser foot can be connected to each other. can be guided by the same guide rod, and the upper knife and the needle can be linked by the same actuating arm, which simplifies the structure, reduces cost and weight, and makes it more compact. It has the effect of further enhancing the aesthetic appearance. In particular, if this is applied to a portable sewing machine, it is possible to solve the problems of reducing the weight and size of the portable sewing machine.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention;
2 is a left side view of FIG. 1, FIG. 3 is a plan view of FIG. 1, and FIG. 4 is a sectional view taken along the line -
Figure 5 is a sectional view taken along the line - in Figure 2, and Figure 6 is a
FIG. 4 is a sectional view taken along the line ``-'', FIG. 7 is a sectional view taken along the ``-'' line in FIG. 2, FIG. 8 is a sectional view taken along the ``-'' line in FIG. FIG. In the figure, 1 is the machine frame, 2 is the guide rod, 3 is the needle, 4 is the needle holder, 5 is the operating arm, 6 is the hollow part, 7 is the presser foot,
8 is the presser bar, 9 is the presser, 10 is the upper knife, 11
is the upper knife operating body.

Claims (1)

[Scope of Claims] 1. A needle holder holding a needle is slidably engaged with a guide rod fixed to a machine frame, and the needle holder is connected to an actuating arm that reciprocates, and at least one of the guide rods The lower part is made into a cylindrical shape, and a presser bar with a presser foot supported on the lower side is slidably inserted into the hollow part, and a presser spring that biases the presser foot downward is engaged with the presser bar. A sewing machine that is characterized by: 2. A needle holder holding a needle is slidably engaged with a guide rod fixed to a machine frame, the needle holder is connected to an actuating arm that moves reciprocally, and at least the lower part of the guide rod is formed into a cylindrical shape. , a presser bar supporting a presser foot on the lower side is slidably inserted into the hollow portion, and a presser spring that biases the presser foot downward is engaged with the presser bar, and further, the operation is performed as described above. An upper knife operating body carrying an upper knife on the lower side is connected to the arm, and the upper knife operating body is slidably engaged with the guide rod,
A sewing machine characterized in that the upper knife, the needle, and the presser foot are guided by a guide rod, and the upper knife and the needle are interlocked by the operating arm.