JPH10127967A - Method and device for feeding fabric for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the generation of fabric deviation between plural pieces of overlapped fabric when feeding the fabric through the feeding teeth of a sewing machine. SOLUTION: This device is provided with a horizontal moving mechanism αarranged on the upstream side of feeding direction and a vertical moving mechanism β arranged on the downstream side of direction where a vertical moving amount on the downstream side of feeding direction is equal with or more than the moving amount on the upstream side. On the initial stage when feeding teeth 1 move up from the upper surface of a needle plate 3 in fabric feeding motion, an upstream end B in feeding direction performs reverse feeding operation at least. The amount of that reverse feeding operation is more at the upstream end B rather than a downstream end A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine, and more particularly to a cloth feed by a feed dog of an industrial sewing machine.

[0002]

2. Description of the Related Art Conventionally, as a cloth feeding device for a sewing machine, FIG.
And FIG. 4 are known. The cloth feeder clamps a feed direction upstream end 2a of a feed base 2 to which a feed dog 1 is fixed to a bifurcated arm 6 fixed to an upper and lower feed shaft 5 that reciprocates and rotates, and a feed direction downstream end 2b. , And is rotatably connected to a horizontal feed arm 8 fixed to a horizontal feed shaft 7 that reciprocates. This reciprocating rotation movement to the vertical feed shaft 5 is performed by rotating the upper shaft 9 clockwise from the eccentric cam 10, the vertical feed rod 12 connected thereto, and one end rotatably connected to the lower end thereof and the other end thereof. It is transmitted via the arm 14 fixed to the vertical feed shaft 5. Further, the reciprocating rotation movement to the horizontal feed shaft 7 is performed by the eccentric cam 11, the horizontal feed rod 13 connected thereto from the upper shaft 9, the connection link 15 one end of which is rotatably connected to the lower end thereof, and the other end. An arm body 16 whose upper end is rotatably connected and whose lower end is fixed to the horizontal feed shaft 7
Conveyed through. 3, 4 in the figure are needle plates,
A presser foot 17 and 18 are a connecting link and a feed adjusting link rotatably supported by a support shaft 19 of the machine frame, respectively. The connecting links 15, 17 and the feed adjusting link 18 constitute a horizontal momentum adjusting mechanism.

[0003] The feeder 2 of this cloth feeder has a bifurcated arm 6
The motion given by the swing motion of the horizontal feed arm 8 as a vertical motion to the upstream end 2a and the motion given by the swing motion of the horizontal feed arm 8 to the downstream end 2b as a horizontal motion are given. As a result, the cloth sandwiched between the feed dog 1 and the presser foot 4 is fed. The movement trajectories of the downstream end (tip of the tooth) A and the upstream end (tip of the tooth) B of the feed dog 1 in the feed direction are as shown in FIG. These movement trajectories are close to ellipses, and the vertical momentum at point A is smaller than the vertical momentum at point B. The cloth sandwiched between the presser foot 4 and the needle plate 3 is fed by the horizontal momentum of the feed dog 1 on the needle plate.

[0004]

In the conventional cloth feeder shown in FIGS. 3 and 4, when two cloths are sewn together, the upper cloth is only held down by the presser foot 4 and is sewn together. Since the lower cloth is fed by the feed dog 1, the lower cloth contacting the feed dog 1 is fed more than the upper cloth contacting the presser foot 4. As a result, puckering (locally generated wavy slack) or sewing (difference in the amount of upper cloth and lower cloth sent) may occur on the lower cloth after sewing.

[0005] Usually, in order to prevent any sewing, the pressure of the presser foot is reduced or an upper feed device is provided. However, in the former, the cloth feeding force is reduced at the time of high-speed sewing. This contributes to the complexity and price rise.

Further, as disclosed in Japanese Patent Publication No. 53-24852, it has been proposed to carry out a reverse feed motion when the feed dog in the cloth feed motion rises from the upper surface of the needle plate. Since the movement acts on the cloth with the entire feed dog, not only is it difficult to obtain a precise feed pitch, but also the cloth being sewn vibrates back and forth, so that the operator has a sense of discomfort. More than anything, the frictional force between the cloth and the presser foot is smaller than the frictional force between the cloths.

SUMMARY OF THE INVENTION It is an object of the present invention to ensure that when a cloth is fed by a feed dog of a sewing machine, a cloth is not shifted between a plurality of cloths.

[0008]

A cloth feeding method for a sewing machine according to the present invention is characterized in that a feed dog 1 is formed by combining vertical movement and horizontal movement.
In the initial stage in which the feed dog 1 rises from the upper surface of the needle plate 3 in the cloth feeding motion, the upstream end B in the feeding direction performs the reverse feeding motion, and the downstream end A performs the normal feeding motion. Is what you do.

The upstream end B and the downstream end A of the feed dog 1 in the feed direction.
Perform a reverse feed motion, and the reverse feed momentum at the upstream end B may be made larger than the reverse feed momentum at the downstream end A.

The downstream end A of the feed dog 1 has a greater vertical movement amount than the upstream end B in the feed direction, and the upstream end B has a cloth feed amount of 1
It is preferable to perform a 0 to 30% reverse movement.

The upstream end B may make a reverse feed motion by 10 to 30% of the cloth feed amount, and the downstream end A may make a normal feed motion.

[0012] It is also possible that the downstream end A makes a reverse feed movement of less than 10% of the cloth feed amount, and the upstream end B makes a reverse feed movement of 10 to 30% of the cloth feed amount.

The horizontal momentum (E, F) of the feed dog 1 on the upper surface of the needle plate 3 is preferably 75% or more of the total horizontal momentum (K, L).

The distance (I, J) from the forward feed start point of the feed dog 1 to the top dead center position is 30 times the total horizontal momentum (K, L).
% Or more

A horizontal motion mechanism α arranged upstream in the feed direction
And a vertical movement mechanism β arranged downstream in the feed direction.

The vertical movement mechanism β preferably increases the vertical movement amount downstream from the upstream side in the feed direction.

In the cloth feeder for a sewing machine according to the present invention, the swing of the horizontal feed shaft 32, which reciprocates once per rotation of the upper shaft, is transmitted to the feed base 2 provided with the feed dog 1 via the feed base link 46. It is transmitted as horizontal motion and transmitted as vertical motion from the two cams 43a and 53 provided on the lower shaft 43 rotating at the same rotation speed as the upper shaft of the sewing machine.
An almost L-shaped upper and lower feed arm with the horizontal feed shaft 32 as a pivot point
It is connected to 49 (Fig. 13).

The feed link 46 is inclined upward in the downstream direction in the cloth feeding direction, and a vertical feeding link 47 on the downstream side in the cloth feeding direction.
Is preferably larger than the vertical swing amount of the upstream vertical link 39 (FIG. 13 (1)).

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a cloth feeding method and a cloth feeding apparatus for a sewing machine according to the present invention will be described with reference to FIGS.

In brief, the movement trajectories of the downstream end (tip of the tooth) A and the upstream end (tip of the tooth) B of the feed dog 1 in the feed direction are shown in FIG. 5 (4) or FIG. ) (The position of the feed dog 1 at the top dead center position of the forked arm 6 is set to 0 °). That is, in the initial stage in which the feed dog in the cloth feed motion rises from the upper surface of the needle plate 3, the upstream end B of the feed tooth 1 in the feed direction is moved faster than the downstream end A.
, The upstream end B performs a relatively reverse feed motion until the downstream end A rises to the upper surface position of the needle plate 3 while starting to rise from the upper surface of the needle plate 3.

This cloth feeder uses a cloth feeder of a type having one vertical motion fulcrum. The horizontal feed motion mechanism α and the vertical feed motion mechanism of the conventional example shown in FIGS. 3 and 4 described above. It is equivalent to replacing β symmetrically. Therefore, members having the same function will be described with the same reference numerals.

In this cloth feeder, the horizontal feed movement mechanism α is arranged on the upstream side in the feed direction, and the vertical feed movement mechanism β is arranged on the downstream side in the feed direction. In order to match, the rotation direction of the upper shaft 9 is clockwise as usual, and the phase of the horizontal feed eccentric cam 11 with respect to the vertical feed eccentric cam 10 is shifted by 180 °. There are two reasons for making such a change in the conventional example, which will be described later. First, although the description is largely the same as that of the conventional example, the outline of the configuration will be described.

In this cloth feeder, the feed end 2a of the feed base 2 to which the feed dog 1 is fixed is clamped by a bifurcated arm 6 fixed to a vertical feed shaft 5 which reciprocates and rotates. The end 2b is rotatably connected to a horizontal feed arm 8 fixed to a reciprocating horizontal feed shaft 7. This reciprocating rotation movement to the vertical feed shaft 5 is performed by rotating the upper shaft 9 clockwise from the eccentric cam 10, the vertical feed rod 12 connected thereto, and one end rotatably connected to the lower end thereof and the other end thereof. It is transmitted via the arm 14 fixed to the vertical feed shaft 5. Further, the reciprocating rotation movement to the horizontal feed shaft 7 is performed by the eccentric cam 11 from the upper shaft 9 and the horizontal feed rod 1 connected thereto.
3, a link 15 having one end rotatably connected to the lower end thereof, and an arm 16 having an upper end rotatably connected to the other end and a lower end fixed to the horizontal feed shaft 7. In the figure, reference numerals 3 and 4 denote a needle plate and a presser foot, respectively.
Reference numeral 8 denotes a connecting link and a feed adjusting link rotatably supported by a support shaft 19 of the machine frame.

This cloth feeder converts the vertical reciprocating motion of the vertical feed rod 12 into a reciprocating rotary motion by the arm 14 and the vertical feed shaft 5, and transmits this to the feed base 2 by the forked arm 6 as vertical motion. Thus, the feed dog 1 can be moved up and down. Further, the vertical reciprocating motion of the horizontal feed rod 13 is converted into a swinging motion by the connecting link 15, and the swinging motion is transmitted to the horizontal feed shaft 7 according to the amount of rotational swing of the arm 16, and the horizontal feed arm 8 By transmitting the feed dog 2 as a horizontal motion, the feed dog 1 can be moved horizontally. As a result, the feed dog 1 is given a motion in which these two types of motion are combined, and the cloth is intermittently fed between the feed dog 1 and the presser foot 4. The movement trajectories of the downstream end A and the upstream end B of the feed dog 1 in the feed direction are respectively shown in FIG.
It is as shown in (2). These motion trajectories are close to ellipses, and the vertical momentum at point A is larger than the vertical momentum at point B. The cloth sandwiched between the presser foot 4 and the needle plate 3 is fed by the horizontal momentum of the feed dog 1 on the needle plate. The cloth feeder is assembled such that the inclination of the feed dog 1 at the highest point is within ± 2 ° with respect to the needle plate 3. This is the same in each of the cloth feeding devices described later.

Here, two reasons mentioned above for changing the conventional example will be described.

One reason is that when the horizontal feed arm 8 is arranged upstream in the feed direction, the feed base 2 is swung up and down around the upstream end 2b, and as shown in FIG. This is because the vertical momentum at the downstream end A in the feed direction can be made larger than the vertical momentum at the upstream end B in the feed direction. This difference increases as the distance from the feed dog 1 to the horizontal feed shaft 7 decreases. In the present invention, the amount of rise from the upper surface of the needle plate when the feed dog 1 is raised most and becomes parallel to the needle plate 3 is 50 points of the vertical movement amount C at the point A.
%, And it is necessary to set the vertical momentum at the points A and B so as to be 50% or more of the vertical momentum D at the point B. FIG. 9B shows a conventional example.

Another reason is that the position of the top dead center of the feed dog is
This is because, as shown in FIGS. 5 (3) and 5 (4), it is advantageous to set it further downstream in the feed direction. The reason will be described below with reference to FIGS. The branch numbers given to the reference numerals of the respective members in FIG. 7 correspond to the time-varying positions, respectively.

In this type of horizontal motion mechanism α, in the case of a model in which the eccentric cam 11 as a drive source is arranged on the Y axis plus side of the coordinate axis having the horizontal feed axis 7 as the origin, the connecting links 15 and 17 and the feed adjusting link 18 depending on which zone the horizontal momentum adjusting mechanism 18 is arranged on, specifically, on the plus side of the X-axis or on the minus side of the X-axis. From both dead points (positions at which the horizontal feed rod 13 is at the uppermost end or the lowermost end of the displacement of the eccentric cam 11), it is determined on which side the swing angle of ± 90 ° becomes larger and which side becomes smaller. Specifically, in the case of the conventional example shown in FIGS. 3 and 4, the horizontal momentum adjusting mechanism is disposed in the first quadrant ([+ X, + Y] zone), and as shown in FIG. ,
The swinging motion is smaller at the right dead center ± 90 ° of the horizontal feed arm 16 (upstream in the feed direction). In the feeder of the present invention shown in FIGS. 1 and 2, the horizontal momentum adjustment mechanism is disposed in the second quadrant ([-X, + Y] zone).
As shown in (1), the right dead center of the horizontal feed arm 16 is ± 90.
In the case of ° (upstream side in the feed direction), the swinging motion becomes larger. As described above, the feeder of the present invention shown in FIG. 1 and FIG. 2 is more advantageous for making the feed dog top dead center position further downstream in the feed direction.

In order to effectively bring the position of the top dead center of the feed dog to the downstream side in the feed direction, the X component in the movement at the intersection of the horizontal feed rod 13 and the connecting link 17 which is the swing fulcrum of the horizontal momentum adjusting mechanism is increased. What should I do? For this purpose, the horizontal feed rod 13 may be lengthened, or the connecting link 17 may be shortened as shown in FIG. By doing so, it is possible to obtain a feed trajectory in which the vertical dead center of the feed dog is shifted downstream in the feed direction, as shown in FIG. Further, the vertical eccentric cam 9 in which the forked arm 6 is at the highest position.
70 ° with respect to the rightmost position of the horizontal movement of the feed trajectory
If the adjustment is made later, a feed trajectory as shown in FIG. 5 (4) can be obtained.

Finally, the details of the path of the feed motion of the feed dog 1 by the cloth feeder will be described with reference to FIG. The trajectory at the downstream end A in the feed direction is a trajectory similar to the conventional one in which the feed dog 1 rises from the upper surface of the needle plate 3 and moves in the forward direction. On the other hand, the feed direction upstream end B
In the trajectory, the vertical momentum D is the vertical momentum C at the point A.
It is smaller (C> D) and rises from the upper surface of the needle plate before point A when the feed dog is raised (point A 271 °, point B 258).
°) until the point A rises to the upper surface of the needle plate 3 (25 degrees).
(8 ° to 271 °) in the reverse feed direction.
The reverse feed amount G at this time is 10 to 30 of the normal feed amount E.
Set to%. Further, the downstream end A of the feed dog 1 in the feed direction,
The horizontal momentum on the upper surface of the needle plate at the upstream end B is represented by E, F,
If the total horizontal momentum is K and L, and the distance from the feed start point of the feed dog 1 to the top dead center position is I and J, E /
K and F / L are 0.75 or more, and I / K and J / L
Is 0.3 or more. Therefore, the substantial cloth feeding section of the feed dog is large, and the cloth feeding force can be increased. Further, in order to obtain the above-described feed motion trajectory, the top dead center of the forked arm 6 is delayed in the range of 60 to 90 ° as the upper axis rotation angle with respect to the rightmost point of the horizontal feed arm 8. Need to be adjusted. Note that these relationships are substantially the same as those shown in FIG. 11 described later, as shown in FIG. 10 (2).

Next, a second embodiment of a cloth feeding method and a cloth feeding apparatus of the type in which up-and-down movement fulcrums are provided at both front and rear ends of a feed base for realizing the feed movement trajectory shown in FIG. This will be described with reference to FIG.

In this type of cloth feeder, in addition to a vertical feed arm 21 fixed to a vertical feed shaft 20, a vertical link 22, and a horizontal feed arm 26 fixed to a horizontal feed shaft 24, 25, a facing upper and lower feed arm 27 and a facing upper and lower link 28 are newly provided, and a horizontal link 29 is added. In this type, the horizontal movement fulcrum 30 may be provided on either the upstream side or the downstream side in the feed direction. Further, in both the type shown in FIG. 1 and the type shown in FIG. 11, the vertical movement can be obtained from the eccentric rotational movement.

The trajectory of the feed dog 1 shown in FIG. 10 (2) will be described. In the cloth feeder of the present invention, a reverse feed portion H is also present in the feed motion trajectory of the feed direction downstream end A, as in the feed direction upstream end B of the feed dog 1. However, the amount H is less than 10% of the horizontal momentum E, and B
The reverse feed G at the point must be 10-30% of the horizontal momentum F.

Furthermore, in this cloth feeder, the conditions for obtaining the above-mentioned feed motion locus are as follows: the vertical motion at the horizontal motion fulcrum 30 on the downstream end A side in the feed direction, and the vertical motion on the upstream end B side in the feed direction. It is almost the same as that of the type shown in FIG. 1, including the reduction of the vertical momentum at the fulcrum 23.

Each of the cloth feeding devices of the type shown in FIGS. 1 and 11 described above, in the initial stage of the cloth feeding motion cycle,
The upstream end B of the feed dog 1 in the feed direction starts rising from the upper surface of the needle plate faster than the downstream end A, and the upstream end B is relatively inverted before the downstream end A rises to the upper surface of the needle plate. Since the feed motion is performed, as shown in FIG. 10 (3), the two-ply cloth 31 is sandwiched between the needle plate 3 and the presser foot 4 on the downstream side,
Only the lower cloth is fed back by the upstream portion of the feed dog 1 and pulled. Therefore, a cloth shift that would be caused by the subsequent forward feed is formed in reverse, and the cloth after sewing does not have a cloth shift and does not cause puckering. Further, since the seam is formed in a state where the cloth is stretched for each stitch, when the tensile force is released, that is, when the cloth comes off from the presser foot and the feed dog, the tension state is based on the tension. Return, the stitches due to thread tightening disappear. The amount of cloth shift varies depending on the fabric and the sewing direction, but by moving point B up and down while the point A is fixed to change the inclination of the feed dog 1, the cloth tension effect increases and decreases, and Tailored adjustments are possible. In addition, depending on the mounting phase, the feeding device shown in FIG.
Both 0 (1) and (2) motion trajectories can be realized.

Next, a third embodiment of the cloth feeding method and the cloth feeding apparatus of the sewing machine according to the present invention will be described with reference to FIGS.

In this cloth feeder, the feed base 2 is provided with the feed dog 1
And the feed dog 1 has a horizontal feed shaft 3 that swings back and forth once per upper shaft rotation.
2 from the lower shaft 43 rotating at the same speed as the upper shaft of the sewing machine (finally, the vertical feed link 39 and the vertical feed link 47). Exercise is given.

The lower end of the feed base arm 34 is fixed to the horizontal feed shaft 32, and the base of an upper and lower feed arm 49 in which two arms 49a and 49b are substantially L-shaped is rotatably connected. . One end of a feed bar link 46 is rotatably connected to the upper end of the feed bar arm 34 by a feed bar shaft 33, and the other end of the feed bar link 46 is fed by a feed bar shaft 44 in the feed direction of the feed bar 2. It is rotatably connected to the downstream end. Slide 2
A vertical feed link 47 is rotatably connected between the downstream end in the feed direction and the tip of the upper arm 49a of the vertical feed arm 49. Lower end of vertical feed link 47 and arm 49a
Is connected by a vertical feed link eccentric shaft 51. The lower arm 49b has an eccentric cam link screw 5
7. One end of the eccentric cam link 59 is rotatably connected by the eccentric cam link step screw 58. The other end of the eccentric cam link 59 is rotatably connected to the eccentric part of the vertical feed eccentric cam 53 fixed to the lower shaft 43.

The upper end of the vertical feed link 39 is rotatably connected to the eccentric portion 43a of the lower shaft 43, and the lower end of the vertical feed link 39 is suspended by the vertical feed link eccentric shaft 40. 2a is rotatably connected to the lower end.

The projecting amount of the feed dog 1 from the needle plate (not shown) is
Vertical feed link eccentric shaft 40, vertical feed link eccentric shaft 51
It is adjusted by adjusting each eccentric amount of.

In addition, in assembling the above members,
Feed slide shaft fixing screw 35, feed slide arm holding screw 36, feed lock screw 37, feed slide link thrust washer 38, feed slide holding screw 41, E-ring 42, feed slide fixing screw 45, feed slide thrust washer 48, vertical feed An arm holding screw 50, an E-ring 52, a vertical feed eccentric cam stopper screw 53, an eccentric cam cover 54, an eccentric cam cover stopper screw 56, and a vertical feed arm thrust collar 60 are required, but description thereof will be omitted.

In this cloth feeder, when the upper shaft (main shaft) is rotated by a sewing machine driving mechanism (not shown), the lower shaft 43 is rotated.
Rotates in the direction of arrow A, and the vertical feed link 39 swings in the direction of arrow B (vertical direction). This gives the feed dog 1 part of the vertical movement. Further, the rotation of the lower shaft 43 in the direction of arrow a causes the eccentric cam link 59 to swing in the direction of arrow c, and the vertical feed link 47 to swing in the direction of arrow d via the vertical feed arm 49. The feed dog 1 has this swinging motion,
The vertical motion is given as a combination of the swing motion of the vertical feed link 39. At the same time, the horizontal feed shaft 32 reciprocates by a predetermined angle in the printing direction by the swing generating mechanism (not shown) interlocked with the upper shaft (main shaft), and the feed arm 34 also swings together. The swinging motion is transmitted to the slide 2 via the slide link 46 as horizontal movement.

Even if the feed dog 1 is adjusted to be horizontal at its top dead center, the amount of eccentricity of the eccentric part 43a of the lower shaft 43 that determines the amount of vertical swing of the vertical feed link 39 and the vertical feed link 4
By adjusting the amount of eccentricity of the vertical feed eccentric cam 53 which determines the vertical swing amount of 7 and the ratio of the length of each of the arms 49a and 49b of the vertical feed arm 49, the feed dog in the cloth feed motion is moved from the upper surface of the needle plate. In the ascending stage, the feed dog 1 is raised first from the upstream side (operator side) in the feed direction, the entire feed dog 1 is raised simultaneously, or the feed tooth 1 is raised first from the downstream side (back side) in the feed direction. be able to. In addition, the feeder link 46
When (1) and (2) are tilted as shown in FIGS. 13A and 13B, the up-down movement direction of the feed base 2 can be set to the direction of an arrow, respectively, and finally the up-down movement and the horizontal movement are combined. 13 (3) can be obtained.

In this cloth feeder, furthermore, by adjusting the amount of eccentricity of each of the above members, the vertical swing of the vertical feed link 47 is made larger than the vertical swing of the vertical feed link 39 as shown in FIG. It is necessary to increase the momentum.

In the cloth feeder shown in FIGS. 12 and 13, when the feed dog 1 rises from the upper surface of the needle plate, the upstream end B in the feed direction rises faster than the downstream end A, and the downstream end A becomes the upper surface of the needle plate. Since the upstream end B performs the backward feeding motion before the position of the cloth is raised, the cloth can be prevented from being displaced between the plurality of cloths, and has the following advantages. That is, the vertical swing amount of the downstream end A and the upstream end B of the feed dog 1 in the feed direction can be set arbitrarily, and when the feed dog 1 rises from the upper surface of the needle plate, it can be raised from any end. Yes, but it is almost horizontal at top dead center. In addition, by adjusting the inclination of the feed dog 1, the movement trajectory of the feed tooth 1 at the downstream end A and the upstream end B in the feed direction can be arbitrarily set. Further, since the horizontal feed shaft 32 of the feed base arm 34 also serves as a swing fulcrum of the upper and lower feed arms 49, the number of parts is small and space can be saved.

Incidentally, this cloth feeding device happens to be the one shown in FIG.
6 is partially similar to the cloth feeder shown in FIG. That is, FIG.
In the cloth feeder shown in FIG. 1, the feed base 2 'has a hanging foot 2'c extending almost directly below the feed dog 1. At the downstream end of the feed base 2 'in the cloth feed direction, the upper end of the feed base arm 34' fixed to the horizontal feed shaft 32 'is connected to the feed base eccentric shaft 3'.
The upper end of a vertical feed link 39 'rotatably supported by an eccentric portion 43'a of a lower shaft 43' is vertically supported at the end of the hanging foot 2'a by a swingable support 3 '. It is rotatably supported by a link eccentric shaft 40 '.

In the cloth feeder shown in FIG. 16, the rotation of the lower shaft 43 'is transmitted to the feed base 2' as the vertical swing motion of the vertical feed link 39 'via the eccentric portion 43'a, and the horizontal feed shaft is rotated. The reciprocating rotation of the predetermined angle of 32 'is performed by the feed arm 34'.
Is transmitted to the feeder 2 ', and they are synthesized to form feed dog 1
Perform the exercise shown in FIG. The amount of protrusion of the feed dog 1 from the needle plate is adjusted by adjusting the respective eccentric amounts of the feed eccentric shaft 33 'and the vertical feed link eccentric shaft 40'.

As described above, the cloth feeder shown in FIG. 16 is partially similar to the cloth feeder of the present invention, but the eccentric shaft 33 'is located downstream of the feed dog 1 in the cloth feed direction. Since the feed dog 1 is moved up and down by the vertical feed link eccentric shaft 40 'almost directly below the feed dog 1 with the feed eccentric shaft 33' as a fulcrum, the vertical momentum on the upstream side in the cloth feeding direction is larger than that on the downstream side. growing. Therefore, when the feed dog in the cloth feed motion rises from the upper surface of the needle plate, the feed dog 1 rises from the downstream side in the cloth feed direction, and puckering and waving occur in the sewn cloth. To prevent them, feed dog 1
Is very limited since the feed dog 1 is originally adjusted to be horizontal at its top dead center. When the feed dog 1 is adjusted so that the entire feed dog 1 is simultaneously raised at the stage of rising from the upper surface of the needle plate in the cloth feeding motion, the upper side of the cloth feed direction at the top dead center becomes higher and tilts greatly. As described above, the cloth feeder shown in FIG. 16 is similar to the cloth feeder of the present invention.

Next, a fourth embodiment of the cloth feeding method and the cloth feeding apparatus of the sewing machine according to the present invention will be described with reference to FIG.

The feed base arm 34 "and the vertical feed link 39" of this cloth feeder perform the same movement as the feed base arm 34 and the vertical feed link 39 in the cloth feeder shown in FIGS. In (1), the feed arm 34 ″ and the second feed arm 61 are connected to the feed arm connecting link 6.
2 so as to be swingable and a parallel link. The upper ends of the feeder links 63 and 64 are swingably supported by the feeder arm connecting link 62, and the lower ends thereof are swingable below the feeder 2 ". In the case shown in (2), the upper ends of the feeder links 63 and 64 have feeder corner pieces 65 guided horizontally by the frame.
It is swingably supported.

In any case, when the feed base links 63 and 64 are inclined downward in the upstream direction in the cloth feed direction, the feed base 2 ″ swings in the direction indicated by the arrow H, and in the opposite direction downward in the cloth feed direction. In the present invention, each feed link 63, 64 is tilted downward in the cloth feed direction upstream, and as shown in (3). The distance between the lower ends of the feed links 63 and 64 is smaller than the distance between the upper ends, and the feed links 64 on the upstream side in the cloth feed direction are shorter than the feed links 63 on the downstream side. With the ascending movement of the feed link 39 ″,
At the stage where the feed dog 1 rises from the upper surface of the needle plate, the upstream end B of the feed plate 2 ", that is, the upstream end B in the feed direction rises faster than the downstream end A, and the downstream end A rises to the upper position of the needle plate. In this case, the upstream end B makes a reverse feed motion, and thus, it is possible to prevent the cloth from being shifted between the plurality of stacked cloths. Or by shifting the support position to the feeder block 65 up and down,
The attitude of the feed dog 1 at the top dead center can be made horizontal.

Finally, a fifth embodiment of the cloth feeding method and the cloth feeding apparatus of the sewing machine according to the present invention will be described with reference to FIG.

In this cloth feeder, the feed direction downstream end 2a of the feed base 2 to which the feed dog 1 is fixed is rotatably connected to the feed base link 68.
Is rotatably connected to a horizontal feed arm 67 fixed to a horizontal feed shaft 66 that reciprocates. Vertical feed links 69 and 70 are rotatably attached to the downstream end 2a and the upstream end 2b in the feed direction of the feed base 2, respectively, and the lower ends of the links 69 and 70 are respectively connected to the vertical feed arms 71 and 72 is rotatably mounted. One end of each of the upper and lower feed arms 71 and 72 is connected to the shaft 7 of the machine frame.
1a, 72a so as to be rotatable.
Upper and lower feed cams 7 fixed to cam shafts 73 and 75, respectively.
4 and 76 are engaged with the respective cam grooves 74a and 76a. The cam shafts 73 and 75 rotate one rotation of the upper shaft, that is, one rotation for one vertical movement of the needle, via a timing belt and gears from a lower shaft (not shown).

As described above, the horizontal feed component of the feed dog 1 is obtained by swinging the horizontal feed arm 67 together with the horizontal feed shaft 66 in the direction of the arrow. The vertical feed component is obtained independently on the upstream side (operator side) and downstream side (opposite worker side) of the feed dog 1 in the feed direction. For example, on the upstream side, the vertical feed cam 76 rotates in a direction indicated by an arrow with the cam shaft as a fulcrum, so that the vertical feed arm 72 is
Swinging in the direction of arrow W with the fulcrum as the fulcrum, the upstream side of the feed base 2 moves up and down together with the vertical feed link 70. This series of operations is the same on the downstream side.

As described above, the upper and lower feed components on the upstream side and the downstream side of the feed dog 1 are independently obtained by the cam grooves 76a and 74a. Therefore, the shape of the cam grooves 76a and 74a may be arbitrarily set. Accordingly, the vertical swing amount of the feed dog 1 can be increased on the upstream side, increased on the downstream side, and can be the same. Further, the timing at which the upstream side and the downstream side of the feed dog 1 are raised above the needle plate 3 and the timing at which the feed dog 1 sinks can be arbitrarily set.

[0056]

Since the present invention is configured as described above, it has the following effects.

That is, displacement and puckering between the upper and lower cloths can be reliably prevented by an inexpensive cloth feeder. In addition, the cloth is clamped between the needle plate and the presser foot on the downstream side, and only the cloth on the upstream side is Since the teeth are reversely fed and pulled by the upstream part of the teeth, the effect of preventing cloth slippage is more reliable, the sewing pitch is accurate, and the cloth does not vibrate back and forth during sewing. These effects are remarkable when the feed amount is 1 mm or more, but can be expected even when the feed amount is less than 1 mm.

[Brief description of the drawings]

FIG. 1 is a diagram of a cloth feeding device (first embodiment) of the present invention, wherein (1) is a front view of a main part and (2) is a perspective view.

FIG. 2 is a side view of a main part of the cloth feeder of the present invention,
(1) is for the power transmission system, and (2) is for the feed dog side.

FIG. 3 is a view of a conventional cloth feeder, wherein (1) is a front view of a main part, and (2) is a perspective view.

FIG. 4 is a side view of a main part of a conventional cloth feeder, (1).
Denotes a power transmission system, and (2) denotes a feed dog side.

FIG. 5 is a diagram showing a movement trajectory of a rear end (A) and a front end (B) in various feed dogs including the cloth feeder of the present invention.

FIG. 6 is a diagram illustrating the relationship between the position of the horizontal momentum adjustment mechanism and the position of the top dead center of the feed dog.

FIG. 7 is a detailed explanatory view of a main part in FIG. 6, wherein (1) is of the present invention and (2) is of a conventional one.

FIG. 8 is a diagram illustrating a means for effectively bringing the top dead center position of the feed dog to the downstream side.

FIG. 9 is a diagram illustrating the significance of arranging the horizontal feed movement mechanism on the upstream side.

FIGS. 10 (1) and (2) are diagrams respectively showing the movement trajectory of the feed dog rear end (A) and front end (B) in the two types of cloth feeders of the present invention, and (3) is the present invention. FIG. 6 is a front view showing a relationship between a feed dog and a cloth at an initial stage of a cloth feeding movement of the cloth feeding apparatus of FIG.

FIG. 11 shows another cloth feeding device according to the present invention (second embodiment).
(1) is a front view, and (2) is a bottom view.

FIG. 12 is another cloth feeder according to the present invention (third embodiment);
FIG. 3 is an exploded perspective view of FIG.

13 (1) and (2) are assembled front views of the cloth feeder shown in FIG. 12, in which the set inclination of the feed link is different, and (3) and (4) are FIG. It is a figure which shows the different movement locus of the feed dog in the cloth feeder shown in FIG.

FIGS. 14A and 14B are diagrams of a main part of still another cloth feeder (fourth embodiment) of the present invention, wherein (1) is a front view, (2) is a bottom view, and (3) is a dimension of each member. It is a figure explaining a change.

FIG. 15 is a main part front view of still another cloth feeder (fifth embodiment) of the present invention.

FIG. 16 is a front view of a main part of another conventional cloth feeding device.

[Explanation of symbols]

Reference Signs List 1 feed dog 2 feed base 3 needle plate 4 presser foot α horizontal movement mechanism β vertical movement mechanism A downstream end of feed dog in feed direction B upstream end of feed dog in feed direction E horizontal momentum of feed dog downstream end on upper surface of needle plate F Horizontal momentum on the upper surface of the needle plate at the upstream end of the feed dog I Distance from the start point of normal feed at the downstream end of the feed dog to the top dead center position J Distance from the start point of normal feed at the upstream end of the feed dog to the top dead center position K Feed Total horizontal momentum at the downstream end of the tooth L Total horizontal momentum at the upstream end of the feed dog

Claims (11)

[Claims] The present invention provides cloth feed movement to a feed dog by combining vertical movement and horizontal movement. In the initial stage in which the feed dog rises from the upper surface of the needle plate, the upstream end of the feed direction is reversed. A sewing machine cloth feeding method that performs a feeding motion and the downstream end performs a normal feeding motion. 2. A cloth feeding motion is given to a feed dog by a combination of a vertical motion and a horizontal motion, wherein an upstream end and a downstream end in a feeding direction are provided in an initial stage when the feed dog in the cloth feeding motion rises from the upper surface of the needle plate. A sewing machine cloth feeding method in which the end makes a reverse feed motion, and the reverse feed momentum is greater at the upstream end than at the downstream end. 3. A cloth feeding motion is given to a feed dog by combining a vertical motion and a horizontal motion, and a vertical movement amount is larger at a downstream end of the feed dog than at an upstream end in a feed direction, and the feed motion in the cloth feeding motion is increased. In the initial stage when the feed dog rises from the upper surface of the needle plate,
A cloth feeding method for a sewing machine in which an upstream end performs a reverse feed movement by 10 to 30% of a cloth feeding amount. 4. A cloth feeding motion is given to a feed dog by combining a vertical motion and a horizontal motion, wherein the downstream end of the feed tooth has a larger vertical movement amount than the upstream end in the feeding direction, and In the initial stage when the feed dog rises from the upper surface of the needle plate,
A cloth feeding method for a sewing machine in which the upstream end performs a reverse feed motion by 10 to 30% of the cloth feed amount, and the downstream end performs a normal feed motion. 5. A cloth feeding motion is given to a feed dog by combining a vertical motion and a horizontal motion, wherein the feed dog has a greater vertical movement amount at a downstream end than at an upstream end in a feed direction. In the initial stage when the feed dog rises from the upper surface of the needle plate,
A cloth feed method for a sewing machine, wherein a downstream end performs a reverse feed movement of less than 10% of the cloth feed amount, and an upstream end performs a reverse feed movement of 10 to 30% of the cloth feed amount. 6. The method according to claim 1, wherein the horizontal momentum of the feed dog on the upper surface of the needle plate is 75% of the total horizontal momentum. 7. The cloth feed of the sewing machine according to claim 1, wherein the distance from the forward feed start point of the feed dog to the top dead center position is 30% or more of the total horizontal momentum. Method. 8. The sewing machine cloth according to claim 1, further comprising a horizontal motion mechanism arranged upstream in the feed direction and a vertical motion mechanism arranged downstream in the feed direction. How to send. 9. A vertical movement mechanism having a horizontal movement mechanism and a vertical movement mechanism having a large vertical movement amount downstream from an upstream side in a feeding direction.
The cloth feeding method for a sewing machine according to any one of claims 1 to 7. 10. A swing of a horizontal feed shaft, which reciprocates once per rotation of an upper shaft, is transmitted to a feeder provided with a feed dog as horizontal motion via a feeder link, and the same rotation as the upper shaft of the sewing machine is performed. The upper and lower feed links are transmitted from the upstream and downstream of the two cams provided on the lower shaft rotating through the upper and lower feed links via respective vertical feed links. A cloth feeding device for a sewing machine connected to an approximately L-shaped upper and lower feed arm having a shaft as a swing fulcrum. 11. The vertical swing amount of the vertical feed link on the downstream side in the cloth feed direction is greater than the vertical swing amount of the vertical feed link on the upstream side in the case where the feed link is inclined upward in the cloth feed direction on the downstream side. A cloth feeder for a sewing machine according to claim 1.