JPS5934451Y2 - Upper feed mechanism of overlock sewing machine - Google Patents

Description

[Detailed explanation of the invention] This invention relates to the upper feed mechanism of the overlock sewing machine.
In particular, the present invention relates to an upper feed mechanism of an overlock sewing machine in which an upper feed dog is disposed in front of a needle in a sewing section of the sewing machine in the cloth feed direction.

In this type of overlock sewing machine, the upper feed mechanism has a cloth cutter rimming drive arm and a needle vertical movement mechanism arranged on one side behind the sewing section of the sewing machine, and a presser foot arm that supports the presser foot is placed at the rear. The base of the upper feed arm for driving the upper feed dog is connected to the back-and-forth movement drive element of the fabric feeding mechanism at a position considerably away from the stitching area in the fabric feeding direction. and is supported at a location where the upper feeding dog extends forward in the cloth feeding direction beyond the seam portion.

For this reason, the distance from the base of the upper feed arm to the upper feed dog is long, and there is play in the joints of the parts to allow movement, and in addition, the upper feed dog can sew thick fabrics. Since the upper feed arm moves on a four-movement trajectory in which the amount of rise from the top surface of the throat plate is much higher than the thickness of the presser foot, when the upper feed arm makes four movements for feeding the cloth, the upper feed dog at the tip moves in the cloth feed direction. When the upper feed dog vibrates in the horizontal direction perpendicular to the presser foot and then descends after rising above the thickness of the presser foot, the lower surface of the upper feed dog hits the upper side surface of the upper feed dog groove formed in the presser foot, producing an impact sound. or break the upper feed dog,
Alternatively, an accident may occur in which the upper feed dog gets stuck on the upper surface of the presser foot and does not come into contact with the fabric, impeding the upper feed function.

In addition, in order to prevent this accident, if the width of the upper feed dog is narrowed, the area of the upper feed dog that comes into contact with the upper surface of the cloth will be reduced, and the cloth feeding force by the upper feed dog will be reduced, and conversely, the upper feed dog will When the width of the feed dog groove is widened, the material gripping surface between the lower feed dog and the entire lower surface of the presser foot in that area decreases, and the material feeding force by the lower feed dog decreases, which is a mutually contradictory drawback. occur and their width is substantially limited.

The purpose of this invention is to prevent the above-mentioned conventional accidents and to ensure reliable cloth feeding by the upper and lower feeding teeth.

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

As shown in FIG. 2, reference numeral 1 denotes a presser arm support whose shaft portion 2 is rotatably supported on the machine frame 27, and at one end thereof is a support portion extending upward and then horizontally. 3 is integrally formed, and is rotated counterclockwise by an operator's operation (not shown).

Reference numeral 4 denotes a rocking body whose center part is rotatably fitted loosely into the shaft part 2, and at its upper end there is a rocking body which is synchronously interlocked with a horizontal feed shaft (not shown) that controls the horizontal feed of the fabric feed mechanism of the sewing machine. Links 5 as horizontal drive elements that reciprocate in the horizontal direction are connected, and a horizontal shaft 8 perpendicular to the cloth feeding direction of a connecting body 7 having horizontal bifurcated parts 6 at the lower end is rotatably supported. do.

Reference numeral 9 denotes an upper feeding arm, which fixes a fitting body 52 supporting a laterally protruding spherical part 51 as the other side of the coupling mechanism to be described later, and also connects the flat part 11 of the base to the bifurcated part 6 of the coupling body 7. They are loosely fitted and connected by a vertical pin 12 so that the upper feed arm 9 can rotate clockwise about the pin 12 as shown in FIG.

Reference numeral 13 denotes a presser shaft that presses the upper feed arm 9. Both side surfaces of the upper feed arm 9 are loosely fitted into a notch 14 at the lower end, and rollers 15 are provided in a portion facing the upper end surface of the upper feed arm.

Above the presser foot shaft 13 is an adjustment screw 1 screwed into the machine frame of the sewing machine.
6 so as to be movable up and down, and always receives a downward elastic force from a spring 17 provided inside the adjustment screw 16.

Reference numeral 18 denotes a scalpel arm that supports a cloth cutting knife (not shown) at its tip, and its shaft portion 19 is linked to the sewing machine mechanism and rotates clockwise while the needle (not shown) pierces the cloth. It fluctuates depending on the timing.

Reference numeral 20 denotes an upper and lower arm as a vertical movement drive element that is formed integrally with the knife arm 18 and extends in the opposite direction.
When the knife arm 18 rotates clockwise, the upper feed arm 9 is moved around the horizontal axis 8 of the connecting body 7 against the force of the spring 17 by rotating the knife arm 18 clockwise. rotate counterclockwise.

Reference numeral 25 denotes a presser arm, whose left base is rotatably connected to a pin 26 having a vertical axis to the support portion 3 of the presser arm support 1, and the right end of the presser arm 25 has a needle hole 28a; 28b, thread stitching pawl 29, upper feed dog grooves 30a, 30b and upper feed dog groove 30a that open toward the front in the cloth feeding direction from the needle drop hole
The presser foot 31 has a pair of feed guides 23 that stand up opposite to each other on both sides, have upward grooves parallel to the upper feed dog groove 30a, and loosely fit on both sides of the upper feed dog 100. It is supported by a pin 32 having a directional axis.

As shown in FIG. 1, reference numeral 33 denotes a presser foot, which has two prongs at its lower end in contact with the upper end of the presser arm 25, supports the upper part so as to be movable up and down relative to the machine frame 27, and is screwed into the machine frame 27. A compression spring 3 provided between the lower end surface of the adjustment screw 34 and the presser body 33
The elastic force of the presser arm 25 normally presses the tip of the presser arm 25 downward.

Reference numeral 36 denotes a well-known pressure release lever, which will not be described in detail, and when operated, the lower end of the presser body 33 is moved between a suppressing position where it contacts the presser arm 25 and a non-pressing position where it rises from the presser arm 25.

Reference numeral 37 designates an upper feeder as a supporting member, which has a bifurcated portion 38 on its left side and a large diameter play hole 4 slightly to the right of the center.
2, and a pair of upper feed teeth 10°1 at the right end.
An upper feed body 46 having a position of 0 is fixed, and this upper feed dog faces the upper feed dog grooves 30a and 30b of the presser foot 31, and one of the upper feed teeth loosely fits into the feed guides 23.

Reference numeral 48 denotes a cylindrical body serving as one side of the coupling mechanism, the base of which is fixed to the right side end surface of the upper feeding body 37 with a screw 49, and the opening is perpendicular to the horizontal direction with respect to the cloth feeding direction. A fitting hole 50 that fits into the spherical portion 51 of the fitting body 520 of the upper feed arm 9 is formed.

Reference numeral 53 designates a side cover of the upper feeder 37, which has a bifurcated portion 54 at its left end and a cover portion 55 at its right end.

The upper feeder 37 and the side cover 53 are connected to a screw 4 screwed into the left side end surface of the presser arm 25 on the left side.
The two-pronged portion 38 of the upper feeder 37 is loosely fitted into the collar 39 that is loosely fitted into the collar 39, the rear washer 41 is placed on the outside of the collar 39, the two-pronged portion 54 of the side cover 53 is further placed on the outside of that, and the screw is inserted. 40 is screwed and fixed to the presser arm 25, the bifurcated portion 54 of the side cover 53, the rear washer 41, and the collar 39 are fixed to the side end surface of the presser arm 25 via the collar 39,
The bifurcated portion 38 of the upper feeder 37 is slidably supported between the outer periphery of the collar 39 and opposing end surfaces of the presser arm 25 and the rear washer 41.

Further, on the right side of the upper feeder 37 and the side cover 53, a small diameter collar 43 loosely fitted into the screw 44 screwed into the right side end surface of the presser arm 25 is positioned in the play hole 42 of the upper feeder 370. ,
By arranging a large-diameter front washer 45 on the outside thereof, further arranging a side cover 53 on the outside thereof, and fixing it by screwing the screw 44 into the presser arm 25, the side cover 54 and the front washer 45 are connected. is fixed to the side end surface of the presser arm 25 via the collar 43, and the free hole 42 portion of the upper feeder 37 is supported so as to be movable left and right and back and forth between the opposing end surfaces of the presser arm 25 and the large-diameter front washer 45. be done.

The cover portion 55 at the right end of the side cover 53 fixed as described above covers the outer surface of the right end of the upper feeder 37 when it makes four movements as described later, and protects the right end of the upper feeder 37 from touching the right end of the upper feeder 37. prevent from entering.

This invention has the above configuration, and Fig. 3.4 shows the upper feeder 3.
The fitting hole 50 of the cylindrical body 48 as one of the coupling mechanisms fixed to the upper feed arm 9 is in a fitted state, and the spherical part 51 of the fitting body 520 as the other coupling mechanism fixed to the upper feed arm 9 is in a fitted state. When the sewing machine is driven, the upper feed dog 10 moves four times in a phase opposite to the vertical movement phase of the lower feed dog (not shown) below the throat plate.

That is, first, the four movements of the spherical portion 51 in FIG. 2 will be explained.
When the needle is removed from the cloth and raised, the link 5 moves to the right in FIG. body T1 pin 12
, moves the upper feed arm 9 to the left, thereby moving the spherical part 51 in a lowered state in the cloth feeding direction, and at this time, the connecting body 7
The horizontal shaft 8 rotates slightly with respect to the lower end of the oscillator 4. Then, when the needle descends and pierces the cloth, the knife arm 18
rotates clockwise around the shaft 19, the roller 21 rises, and the lower surface of the upper feed arm 9 is pushed up against the acting force of the spring 17 via the leaf spring 22, whereby the upper feed arm 9 The spherical portion 51 rotates counterclockwise around the horizontal axis 8 of the connecting body 7.
will rise.

Then, when the link 5 moves to the left, the oscillating body 4 connecting body 7
．． The upper feed arm 9 swings or moves in the opposite direction to that during the cloth feed, and the spherical portion 51 moves back to the right in FIG. 1 in an elevated state.

When the needle further rises and comes out of the cloth, the scalpel arm 18
rotates counterclockwise around the shaft 19, and the roller 21 descends, and the upper feed arm 9 rotates clockwise around the horizontal shaft 8 of the connecting body 7 due to the action of the spring 17, so that it becomes spherical. The portion 51 is lowered and returns to its initial state.

The movement of the spherical part 510 is transmitted to the upper feeder 37 through the fitting hole 50 of the cylinder 48 in FIGS. 3 rotates clockwise around the collar 39, the lower surface of the upper feed dog 10 at the tip presses the cloth against the upper surface of the throat plate, and then, when the spherical portion 51 moves in the cloth feed direction, the two prongs color 3
9, the cloth is fed by the upper feed dog 10. Next, when the spherical part 51 rises, the forked part rotates counterclockwise around the collar 39, and the upper feed dog 10 feeds the cloth. Then, when the spherical part 51 moves in the opposite direction to the cloth feeding direction, the fork part slides on the collar 39 and the upper feed dog 1
0 returns to the original position, and the upper feed dog 10 performs four cloth feeding movements.

The tip of the upper feed dog 10 moves inside the pair of feed guides 23 over the entire range of its four movements.

As described above, this invention is designed to operate the upper feed dog 10 of the overlock sewing machine, which is placed in front of the needle in the sewing section of the sewing machine in the cloth feed direction and feeds the cloth through four movements, on both sides over the entire range of the four movements. The feed guides 23 to be guided are moved to the presser foot 3.
1, the upper feed dog 10 does not come off from the feed dog grooves 30a, 30b of the cloth presser foot 31 in the direction perpendicular to the cloth feeding direction during its movement. The sewing machine can be driven at high speed without generating impact noise hitting the upper surface on the side of the groove or breaking the upper feed dog.
This has the effect of improving sewing work efficiency, stabilizes the cloth feeding function of the upper feed dog, and also maintains an appropriate area between the upper feed dog and the part of the presser foot excluding the feed dog groove, so that the upper and lower This has the effect of stabilizing the cloth feeding force due to the feed dog, making the amount of cloth feeding accurate, and improving the quality of sewn products.

In the illustrated embodiment, the upper feed arm 90 spherical portion 51
The above-mentioned type of upper feed mechanism is shown in which the movement is transmitted to the upper feed body 37 which is supported on the side surface of the presser arm 25 and has an upper feed dog 10. The same effect can be obtained even if the present invention is applied to the same.

In the illustrated embodiment, the base of the upper feed arm 90 is supported by the swinging body 5 that swings in conjunction with the cloth feed mechanism, and the upper feed arm 9 is moved up and down in conjunction with the upper and lower arms 20 that are integrated with the knife arm 18. Although the upper feed arm 9 is configured to move, the base of the upper feed arm 9 is connected to the feed base of the needle feed tooth, and the upper feed arm 9 is moved up and down in conjunction with the needle up and down movement mechanism and other mechanisms. Even if the present invention is applied to a device in which the upper feed dog is moved four times via the feed arm 9, similar effects can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic perspective view of the presser foot of an overlock sewing machine, Figure 2 is a perspective view of the driving part of the upper feed mechanism with the presser foot arm removed, Figure 3 is a side view of the presser foot arm, and Figure 4 is a side view of the presser foot arm. The figures are a cross-sectional view taken along the line IV--IV in FIG. 3, and FIG. 5 is a cross-sectional view taken along the line V-V in FIG. In the figure, 9 is an upper feed arm, 10 is an upper feed dog, 23 is a feed dog guide, 30a and 30b are feed dog grooves, and 31 is a cloth presser foot.

Claims (1)

[Claim for Utility Model Registration] The base part behind the sewing machine stitching part in the cloth feeding direction is connected to the front-rear drive element of the cloth feeding mechanism so as to be rotatable about a horizontal axis perpendicular to the cloth feeding direction, and the intermediate part is The upper feed arm 9 is connected to a vertical drive element having a vertical movement phase opposite to that of the lower feed dog, and supports the upper feed dog 10 in front of the needle in the sewing machine sewing section in the cloth feeding direction. The upper feed grooves 30a and 30b are open so that the upper feed dog 10 can move up and down to move in and out while receiving the elastic force in the direction of pressure contact with the top surface of the plate, and the upper feed grooves 30a and 30b are open in the cloth feeding direction over the entire range of the four movements of the upper feed dog. An upper feed mechanism for an overlock sewing machine, comprising: a presser foot 31 provided with feed dog guides 23 standing upright on both sides of the upper feed dog in the orthogonal horizontal direction;