JPS5820228Y2 - sewing machine needle bar guide device - Google Patents

Description

[Detailed description of the invention] This invention is a needle bar guide device for sewing machines, especially when sewing embroidery.
This invention relates to an improvement of a needle bar support drive structure that pushes up the presser foot together with the presser foot in the second half of the needle bar's upward stroke.

The needle bar of a regular sewing machine is supported so as to be vertically slidable by a guide means which is held at two upper and lower parts by sleeves.

In order to shorten the length of the upper end of the needle bar, the present invention has a shortened and hollow upper end of the needle bar, in which a guide piece with an axial hole is fixed to the upper end of the needle bar, instead of the conventional structure. , has a sliding guide structure in the form of a piston and a cylinder through which a guide rod is suspended from the upper side, and the guide piece pushes up the embroidery presser foot when it rises, and the guide piece and the A related structure is also provided between the presser foot and the presser foot so that they can slide freely against each other and prevent rotation of the needle bar.By using such a structure, the needle bar, etc. can be made smaller and lighter, making it easier to use the sewing machine. The purpose is to help make it more compact.

Referring to the drawings, a bearing part 1a is formed at the lower end of an arm 1 of the sewing machine, and a needle bar 3 is guided and supported so as to be movable up and down by a sleeve 2 fitted in this part.

The upper part of the needle bar 3 is formed to be hollow from the upper end to an appropriate length or the entire length thereof, and has a guide piece 4 having an axial hole 4a communicating with the hollow cavity (not shown). is fixed by appropriate means.

The upper end sides of the guide rods 5, which pass through the shaft hole 4a and are slidable relative to each other along the axial direction of the needle bar 3, are supported via a guide supporter 6 supported within the upper part of the tip of the arm 1. The needle bar 3 is guided up and down by a guide rod 5 on its upper side and by a sleeve 2 on its lower side.

- crank pins 9 are implanted at eccentric positions on the end surface of a disk 8 fixed to the shaft end of the upper shaft 7 of the sewing machine, and a drive arm whose rear end is slidably supported by a pivot pin 10. The crank pin 9 is slidably fitted into a rear slot 12 formed near the pivot end of the drive arm 11, whereby the drive arm 11 is given a swinging motion as the upper end 7 rotates.

Another front slot 13 is provided on the swinging end side of the drive arm 11, and a slider 15, which has a pin 14 installed laterally and slidably fitted into this front slot 13, is attached to the needle bar 3. When the drive arm 11 swings, the slider 15 can move up and down along the needle bar 3, and the slider 15 is fitted so as to be able to move up and down along the needle bar 3. When gripped, the drive arm 11
The swinging causes the needle bar 3 to move up and down.

Therefore, to explain the handle mechanism in which the guide piece 4 grips and integrates the slider 15, a latch 1 is attached to one side of the guide piece 4.
6 is pivotally mounted, and the hook portion 16a at the lower end of the latch 16, which biases the spring 17 counterclockwise when viewed from the mounting side, engages with the lower step portion 15a of the slider 15. The needle bar 3 is then driven up and down in this elastically locked and held state.

Note that the needle bar 3 itself has one end connected to the arm 1 by a support pin 18.
When the slider 15 is released from the latch 16, the slider 15 normally assumes the highest position, and the other end of the lift spring 19 is securely connected to the guide piece 4. is configured to remain in the rest position.

Corresponding to the upper part of the latch 16, the legitimate child part 6b formed by bending in the opposite direction to the hook part 16a can be engaged with and detached from the legitimate child part 6b. Means are provided for guiding the portion 16b to control the latch 16 in its unlocked state against the spring 17.

That is, a cam portion 21 a that provides the above-mentioned heir-part guiding effect to the front end of a cam plate 21 which is pivotably supported to the arm 1 by a screw 20 so as to be horizontally rotatable below the guide supporter 6. is configured, and the other end on the rear side is an electromagnet 2
2, when the cam plate 21 is subjected to a suction operation by its excitation control, the cam plate 21 rotates counterclockwise when viewed from above, so that the cam portion 21a can be engaged with the latch legitimate child portion 16b. position and when the electromagnet 22 is de-energized,
The cam plate 21 is rotated by a return spring means, the details of which are not shown, in the direction of the arrow A shown in FIG.

Note that such engagement and disengagement of the cam portion 21a is possible if the engagement operation is performed while the guide piece 4 is raised.
The upper edge of 1a hits the latch heir part 16b, and as shown in FIG. By making the guide piece itself a flexible material, when the guide piece 4 is slightly lowered from the illustrated state, the latch 16 rotates against the spring 17, and the latch heir part 16b moves toward the cam part 21a. The front edge of the cam plate 21 comes out on this double cam edge, and at this time, the cam plate 21 is
The deflection is restored and the cam portion 21a is fully secured.

As shown in FIGS. 2 and 3, the lower part of the presser foot 23 is slidably inserted into the needle bar 3, and the upper part is slidably guided and supported by the guide rod 5. The upper end piece 23C of the upper part, which is bent into a letter shape, is biased downward by the presser foot spring 24 from above, and when the guide piece 4 rises, the upper end piece 23C of the upper part is lifted up in the latter half of the upward stroke and becomes the presser foot. The presser foot 23 also rises against the spring 24.

There is a slit in the upper front of the presser foot 23 parallel to the needle bar 3).
23a, and a slide pin 4b protruding from the front surface of the guide piece 4 is inserted into the slit 23a.
It is slidably engaged with a and guided there like a rail.

The middle portion 23d of the presser foot 23 allows the needle bar 3 to slide therethrough.

Further, the presser foot 23 is connected to a thrower Hb provided on the lower surface of the arm 1.
The needle bar 3 is prevented from rotating through the presser foot 23 from where it is exposed downward.

The needle bar guide device of the present invention has such a configuration, and the electromagnet 22
In the non-energized state, that is, in the separated state in which the cam portion 21a of the cam plate 21 cannot act on the latch 16, the latch 16 locks and holds the lower step portion 15a of the slider 15 by the spring 17, so that the slider 15 When the drive arm 11 swings up and down with the rotation of the main shaft 7, the vertical movement transmitted to the slider 15 through the front slot 13 is caused by the movement of the needle bar 3 together with the presser foot 23. gives the behavior of

Therefore, when the needle bar 3 is lowered, the presser foot 23 also starts to lower at the beginning due to the action of the presser foot spring 24. After contacting the surface, only the needle bar 3 continues to descend, and the stitch is shaped by the cooperation of the needle 25 attached in the conventional manner and a bobbin thread mechanism (not shown), and then the needle bar 3 In the ascending stroke, the guide piece 4 comes into contact with the upper end piece 23C of the presser foot 23 at a timing after the tip of the needle 25 leaves the surface of the workpiece fabric in the second half of the ascending stroke. Push up.

During such lifting and lowering operations, the needle bar 3 is guided up and down by the guide rod 5 on the upper side and by the sleeve 2 on the lower side, and the slide pin 4b is guided along the slit 23a of the presser foot 23. By this, sewing machine arm 1
In contrast, it moves up and down while being prevented from rotating via the presser foot 23.

A description of the operation when the electromagnet 22 is excited, that is, when the latch 16 releases the connection with the slider 15, will be omitted.

In the present invention, the upper side of the needle bar is guided upward along the upper side of the needle bar by introducing a stationary guide rod through the inside of the shaft instead of supporting means such as the usual bearing metal. In the second half of this upward stroke, the head of the needle bar acts directly to push up the presser foot, and the presser foot also guides the upper part along the guide rod, and the middle section. The needle bar is provided with support and guidance along the needle bar, and the slide pin on the needle bar head is guided by the slit on the presser foot side like a rail, which acts to prevent the needle bar from rotating. The structure related to the presser foot is compact, and the weight of the needle bar that moves up and down can be reduced, and it can also be expected to have the effect of reducing vibrations in the sewing machine.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of a sewing machine embodying the present invention, with some constituent elements removed; Fig. 2 is a side sectional view of the part;
FIG. 3 is a transparent perspective view of the sewing machine portion corresponding to FIG. 1. 1... Sewing machine arm, 2... Sleeve, 3... Needle bar, 4... Guide piece, 4
a...Shaft hole, 4b...Slide pin,
5...Guide rod, 6...Guide supporter, 7...Main shaft, 11...Drive arm, 13...Front slot, 14 ...Pin, 15 ...Slider, 23 ... Presser foot, 23a ... Slit, 23b ... Presser foot leg, 23 C. ...Top end piece, 23d...
...Middle section, 24... Presser foot spring, 25...
···needle.

Claims (1)

[Scope of utility model registration request] A needle bar whose lower part is slidably guided and supported in the axial direction by a sleeve fitted to the lower surface of the arm of the sewing machine is formed so that at least its upper part is hollow, and the upper end of the needle bar is provided with a hollow part. A guide piece having a shaft hole that communicates with the guide piece is fixed to the
A means for transmitting the vertical swing of a drive arm driven by rotation of the main shaft of the sewing machine to the guide piece is provided, and the guide rod is slidably inserted into the shaft hole from above to support the guide rod within the arm. Further, a slide pin is provided protruding from the front surface of the guide piece, and the side surface of the presser foot is bent into a self-shape, and the guide rod is attached to the upper end piece of the presser foot, and the needle bar is attached to the middle part of the presser foot. A slit is provided in the upper front surface of each of the needle bars so as to be slidable therethrough, and a slit is provided on the front surface of the upper part of the needle bar to engage and guide the slide pin, and to apply a downward bias to the presser foot and to prevent the needle bar from rising in the upward stroke. A needle bar guide device for a sewing machine, characterized in that a presser foot spring is provided so that the guide piece bends when pushing up the upper end piece in the latter half of the process.