JPS6012520Y2 - Upper feed mechanism of sewing machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an upper feed mechanism of a sewing machine, and more particularly to an upper feed mechanism of a sewing machine that raises an upper feed dog in conjunction with the rise of a presser bar.

This type of upper feed mechanism has the following functional characteristics.

That is, as shown in FIGS. 1 and 2, in order to attach or detach the fabric below the presser foot 8, the sewing machine is stopped with the needle at approximately the top dead center.
At this time, the upper feed dog 16 is in the middle of feeding the cloth, so the spring 19
is pressed downward by the acting force of

Also, a push-up body 10 of the presser foot 6 fixed to the lower end of the presser bar 1
The upper surface and the retaining portion 14 of the feed table 11 facing upward
There is a gap between it and the bottom surface.

If there is no gap and the upper surface of the push-up body 10 and the lower surface of the engaging part 14 are brought into close contact with each other in the state shown in FIG. When the presser foot 8 is raised and the presser foot 6 is raised, the push-up body 10 of the presser foot 6 pushes up the engaging portion 14 by that amount and the feed base 11 also rises, thereby raising the upper feed dog 1.
6 also rises, and the upper feed dog 16 is placed in the thin part of the cloth following the stepped part.
A phenomenon occurs in which the upper feed teeth 16 are unable to feed the cloth.

For this reason, even if the stepped part of the fabric is fed behind the presser foot 8 and the presser foot 6 is raised, as shown by the dashed line in the second drawing, the feed table 11
In order to allow the upper feed dog 16 to feed the cloth without raising the presser foot 6, a certain gap A is required between the upper surface of the push-up body 10 of the presser foot 6 and the lower surface of the engaging portion 14 of the feed base 11. do.

Since the gap A is required, the following problems occur.

That is, when the presser bar 1 is first raised from the state shown in FIG. will rise by that gap, and the shaft 13 at the rear of the feed table 11 will rise, but since the upper front side in the cloth feeding direction is pressed downward by the spring 19, it will rotate slightly clockwise around the shaft 13 and the tip The upper feed dog 16 does not rise, so that the upper feed dog 16 is lowered below the lower surface of the presser foot 8 as shown in FIG.

When the presser bar 1 further rises from this state, the feed bar 11
The engaging portion 14 of the presser foot 6 is pushed up by the push-up body 10 of the presser foot 6, and the shaft 13 at the rear also rises at the same time.
1 rises with the presser foot 8.

Therefore, when the presser foot 1 is raised to the highest level, the lower surface of the upper feed bar 16 is at a lower position than the lower surface of the presser foot 8, which makes it difficult to attach the cloth to the lower surface of the presser foot, which has the disadvantage of reducing work efficiency. .

This device uses a blocking mechanism to prevent the rear end of the feed bar from rising during the rise of the presser bar, so that the lower surface of the upper feed dog is at least as aligned with the lower surface of the presser foot in conjunction with the rise of the presser bar. - or above, thereby eliminating the above-mentioned conventional drawbacks.

Examples of this invention will be described below with reference to the drawings.

In Figures 1 and 2, reference numeral 1 denotes a hollow presser bar, which is loosely fitted into a bearing 3 fitted and fixed to a machine frame 2 so as to be movable up and down, and although not shown, always receives a downward elastic force and It is provided so that it can be moved up and down in conjunction with an appropriate push-up mechanism.

A support body 4 has a base fixed to the lower end of the presser bar 1, and forms bifurcated support arms 5 extending rearward and downward in the cloth feeding direction.

6 is a presser foot, the upper end of which is attached to the end surface of the support body 4 with a screw 7.
A push-up body 10 is formed at the lower end to support the presser foot 8, protrude downward from the support body 4, and have a groove 9 on the upper surface parallel to the cloth feeding direction.

Reference numeral 11 denotes a feeding table, in which a horizontal elongated hole 12 formed in the center and long in the cloth feeding direction is inserted into the support arm 5 of the support body 4 so that the shaft 1
3, and supports it so that it can move and rotate in a direction parallel to the cloth feeding direction, and has an inverted shape in front of the support part in the cloth feeding direction, so that its tip passes through the lower end of presser bar 1. An engaging portion 14 extending from the upper surface of the push-up body 10 of the presser foot 6 is formed.

Reference numeral 15 denotes an upper feed foot, the base of which is fixed to the lower surface of the feed base 11, and an upper feed tooth 16 formed at the tip.

Reference numeral 17 denotes an auxiliary feed rod, which loosely fits inside the presser bar 1, has a lower end protruding from the lower end of the presser bar 1, and supports a ball 18 on a portion of the feed base 11 facing the upper surface of the engaging portion 14.

Reference numeral 19 denotes a spring, which loosely fits inside the presser bar 1 on the upper end surface of the sub-presser bar 17, and is provided so that the pressure of the spring 19 can be adjusted by an adjustment screw 20 screwed into the presser bar 1 from above.

Reference numeral 21 denotes an L-shaped swinging body, whose central portion is swingably supported by a shaft 22 with respect to the support arm 5, and whose one end faces the surface of the engaging portion 14 of the feed base 11.

23 is a vertical shaft supported on the machine frame 1, which fixes the bases of an arm 24 extending horizontally and an arm 25 extending downward;
The tip of the arm 24 is connected to the lower end of a rond 28 that moves up and down by an eccentric cam 27 provided on the main shaft 26, and the vertical shaft swings in conjunction with the rotation of the main shaft 26.

Reference numeral 29 denotes a connecting link, whose both ends are rotatably connected to the upper end of the swinging body 21 and the lower end of the arm 25.

30 is an interlocking body whose central part is rotatably supported with respect to the machine frame 2, and whose upper end is connected to an arm 32. Link 3
Connect via 3.

A connecting link 34 has one end rotatably connected to the lower end of the interlocking body 30 via a shaft 35, and the other end rotatably connected to the rear end of the feed table 11 via a shaft 36.

Reference numeral 37 denotes a screw as a blocking body, the upper part of which is screwed into the lower end surface of the arm 25 and fixed with a lock nut 38, and the head of the lower end is connected to the shaft 36 which is the connection point of the connecting link 34 with the rear end of the feed base 11. facing upwards near the area.

This invention has the above structure, and its operation will be explained next.

FIG. 2 shows a state in which the upper feed dog 16 is feeding the cloth in the feeding direction, and the vertical shaft 23 is rotated counterclockwise (hereinafter referred to as "reverse direction"), and the oscillating body 21 is connected to the shaft 22 through the connecting link 29.
As a result, one end of the oscillating body 21 moves downward from the lower surface of the retaining part 14 of the feed base 11, and the feed base 11 is rotated in a clockwise direction (hereinafter referred to as the positive direction). The upper feed dog 16 presses the upper surface of the cloth under the force that presses the sub presser bar 179 downward through the ball 18 and receives rotational force in the positive direction about the shaft 13.

Also, the upper surface of the groove 9 of the push-up body 10 of the presser foot 6 and the feed base 11
There is a gap A between the lower surface of the engaging part 14 and the step part of the fabric pushing up the rear of the presser foot 8 and the presser foot 6 rising, but the feed bar 11 does not rise and therefore the upper feed dog 16 continues to press the upper surface of the cloth.

Further, the horizontal shaft 31 rotates in the opposite direction in conjunction with the main shaft 26, rotates the interlocking body 30 in the forward direction via the link 33, and moves the feed base 11 via the connecting link 34, thereby The upper feed dog 16 moves in the cloth feeding direction while pressing the upper surface of the cloth due to the elastic force of the spring 19 described above to feed the cloth.

Next, when the rotation of the horizontal shaft 31 in the opposite direction approaches the end,
The vertical shaft 23 begins to rotate in the forward direction, and the oscillating body 21 rotates in the opposite direction about the shaft 22 via the connecting link 29, and one end of the oscillating body 21 rotates in the opposite direction around the shaft 22, and one end of the oscillating body 21 touches the lower surface of the retaining portion 14 of the feed base 11 with the spring 19. It is pushed up against the elastic force, and as a result, the feed table 11 rotates in the opposite direction about the shaft 13, and the upper feed dog 16 rises from the upper surface of the cloth.

Next, the horizontal shaft 31 begins to rotate in the positive direction, and as a result, the feed table 11 moves in the opposite direction to the cloth feeding direction while the elongated hole 12 slides on the shaft 13, and the upper feed dog 16 moves in the direction opposite to the cloth feeding direction. Returns while rising.

Furthermore, when the rotation of the horizontal shaft 31 in the positive direction approaches the end,
The vertical shaft 23 begins to rotate in the opposite direction, the oscillating body 21 rotates in the forward direction, and one end of it begins to descend, and the engaging portion 14 of the feed bar 11 moves to the shaft 13 due to the elastic force of the spring 19. The upper feed dog 16 rotates in the forward direction following the lowering of one end of the rocking body 21, and the upper feed dog 16 comes into pressure contact with the upper surface of the cloth.

By repeating the above movement, the upper feed dog 16 performs a cloth feed movement on the upper surface of the cloth.

To complete the stitching and remove the cloth, as shown in Figure 2,
The needle 39 is removed from the fabric and the sewing machine is stopped with the needle bar 40 near the top dead center.

From this state, the presser bar 1 is moved between the upper surface of the groove 9 of the presser foot 6 and the engaging portion 1 of the feed base 11 by an appropriate lifting mechanism (not shown).
4, the support 4 and presser foot 6 rise, and the shaft 13 and presser foot 8 begin to rise. Since the upper surface of the joining part 14 is pressed, it rotates in the positive direction around the shaft 13, and during this period, the presser bar 1 moves upward in the third direction.
As shown in the figure, the presser foot 8 rises, but the upper feed dog 16 does not rise.

As shown in FIG. 3, when the gap between the upper surface of the groove 9 and the lower surface of the engaging portion 14 disappears and the presser bar 1 rises to the point where these surfaces come into contact, the lower end of the head of the screw 37 is brought into contact with the upper end surface of the connecting link 34. , and prevents the shaft 36, which is the connecting point between the connecting link 34 and the feed table 11, from rising any further.

If the presser bar 1 is further raised from the state shown in Fig. 3,
The support body 4 and the presser foot 6 further rise, and the presser foot 8 further rises, and the feed table 11 is moved to the shaft 36 by the screw 37.
is prevented from rising, and as the shaft 13 rises as the support 4 rises, it rotates in the opposite direction about the shaft 36 against the elastic force of the spring 19, and as a result, as shown in FIG. As shown, the upper feed dog 16 at the tip of the feed base 11 moves to a position higher than the presser foot 8.

In this state shown in FIG. 4, the cloth on the underside of the presser foot 8 is removed, and the cloth to be sewn next is inserted into the underside of the presser foot 8.

Further, when the presser bar 1 is lowered, each part moves in the opposite direction to the above, and each part returns to its original state as shown in FIG.

As described above, in this invention, since the upper feed dog 16 does not rise when the presser bar 1 initially rises, the fabric in the part corresponding to the upper feed dog 16 is thin, and the fabric on the lower surface of the presser foot 8 that does not correspond to the upper feed dog 16 is thin. Even when a fabric with a thick step is fed into the lower surface of the upper feed dog 16 and the presser foot 8, and the presser foot 8 is pushed up by the step, the upper feed dog 16 does not rise and the fabric becomes thin. Since they are in contact with each other, the presser foot is used to reliably feed and sew the fabric, as well as to stop the sewing machine and remove the fabric from the presser foot 8 and the lower surface of the upper feed dog 16, and insert the fabric into the lower surface. 1 to the highest position, the upper feed dog 16 rises above the presser foot 8 and does not protrude downward from the bottom surface of the presser foot 8, making it easier to insert the fabric into the bottom surface of the presser foot 8, improving work efficiency. It has the effect of

In the illustrated embodiment, the elongated hole 12 of the feed table 11 is loosely fitted into the shaft 13 to enable horizontal movement and rotation in the cloth feeding direction. The link is rotatably supported downward, and a feed base 1 is attached to the lower end of the link.
．． 1 can also be rotatably connected by a shaft.

Further, although the screw 37 as a blocking member is supported on the lower end surface of the arm 25, this blocking member may be provided in a part that does not rise in conjunction with the rise of the so-called presser bar 1, such as the interlocking body 30 or the machine frame 2. A similar effect can be obtained.

Further, a desired height of the upper feed dog 16 at the highest position of the presser bar 1 shown in FIG. 4 can be obtained by appropriately selecting the position of the lower end of the head of the screw 37.

[Brief explanation of the drawing]

Fig. 1 is a perspective view, Fig. 2 is a side view showing the state of the upper feed mechanism during cloth feeding, Fig. 3 is a side view showing the state of each part when the presser bar is initially raised, and Fig. 4 is the presser bar. It is a side view which shows the state of each part when it is set to the highest position.

Claims (1)

[Scope of Claim for Utility Model Registration] A presser bar 1 which is supported on a machine frame so as to be movable up and down, has a presser foot fixed to its lower end, is always subject to downward elastic force, and is movable up and down in conjunction with a presser foot lifting mechanism. , a support 4 fixed below the presser bar, and a support part supported below the support and located further in the cloth feeding direction than the presser bar, which is horizontally reciprocated along the cloth feeding direction and rotated around the horizontal axis. A feed base 1 which is movable and has a retaining part 14 and an upper feed dog 16 fixed above and below in front of the supporting part in the cloth feeding direction.
1, and the engagement portion 14 of the feed bar is linked only in the latter half of the rise of the presser bar.
A push-up body 10 is fixed to a presser foot or a support body so as to engage with the feed plate and raise the feed plate, and a push-up body 10 is connected horizontally to the rear end of the feed plate in the cloth feeding direction via a connecting link 34 and is fed in conjunction with the main shaft. A first moving mechanism that reciprocates the table along the cloth feeding direction, and an elastic body 19 that has an elastic force weaker than the elastic force of the presser bar and presses the feed table downward in front of the support part of the feed table in the cloth feed direction. , an L-shaped rocking body 21 whose intermediate part is rotatably supported on a support body and whose one end faces the lower part of the engagement of the feed base, and the other end of the rocking body is connected to the horizontal connecting link a second interlocking mechanism that is connected to the main shaft to swing the rocking body and move the feed table up and down; 34, and supported on a part that does not move in conjunction with the rise of the presser bar when the sewing machine is stopped, so that the upper feed dog rotates in the direction in which the upper feed dog rises in conjunction with the rise of the presser bar after contact. An upper feed mechanism of a sewing machine equipped with a blocking mechanism, and.