JPS597477B2 - Cloth feed mechanism in sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cloth feeding mechanism in a sewing machine.

Since the conventional feed dog is constructed so that the center of oscillation is simply moved downward, the movement trajectory is mainly as shown in Fig. 1A, where the feed dog a rises from the tip and moves in an elliptical manner. Therefore, as shown in Fig. 1B, when feeding fabric b forward or backward, there is little contact between the feed dog a and the fabric in a horizontal position near E, and therefore the feed dog Since the parts a are completely in contact with each other and are averaged, it is not possible to obtain a feed, which causes wrinkles and disordered stitches, especially in thin fabrics.

In FIG. 1, C is the throat plate, and d is the presser foot.

In view of the above-mentioned conventional drawbacks, the present invention makes the teeth of the feed dog protrude evenly from the upper surface of the throat plate so that they are in contact with the fabric, and the fabric is always fed horizontally, thereby making it possible to reliably feed the fabric without wrinkles. The purpose is to provide a cloth feeding mechanism in a sewing machine.

The structure of the present invention will be explained in detail based on the embodiment shown in FIG. 2 and below.

As shown in FIG. 3, a lower shaft 4, which rotates in conjunction with a sewing machine drive source (not shown), is inserted into and supported by support pieces 2 and 3 that project from the machine frame 1 at intervals.

A horizontal feed cam 5 and a vertical feed cam 6 are mounted on the lower shaft 4 at intervals.

Further, a U-shaped pedestal 7 is fixed to the machine frame 1 in parallel with the lower shaft 4, and a feed adjuster shaft 8 is mounted thereon.

One end of a feed adjuster arm 9 is pivotally attached to the shaft end of the feed adjuster shaft 8, and a feed adjustment link 11 is pivotally connected to the other end of the feed adjuster arm 9 via a horizontal link 10. An adjustment link 11 is positioned parallel to the feed adjuster arm 9, and a horizontal feed rod 12 and a horizontal feed link 13 are pivotally connected to the other end of the feed adjuster arm 9, respectively.

The other end of this horizontal feed rod 12 is connected to the horizontal feed cam 5.
are barking at each other.

Further, a feed base 14 is fixed to the machine frame 1 in parallel with the lower shaft 4 and on the opposite side of the feed adjuster shaft 8.

This feed table 14 is formed in a U-shape, with rising portions 15 at both ends.
．． 16 is provided, and a vertical feed shaft 17 is rotatably horizontally mounted parallel to the lower shaft 4.

This seventh lower feed shaft 171 has a vertical feed actuating arm 19 pivoted thereon so that the contact portion 18 at the upper end always engages with the vertical feed cam.

Further, the connecting portion 21 side of a horizontal feed member 20 having a tenon-shaped shape is fitted into the vertical feed shaft 17.

One arm 22 of the horizontal feed member 20 is pivotally connected to the horizontal feed link 13, and the other arm 23 is formed shorter than the arm 22, and the end thereof is raised to form a swing arm 24. However, a two-pronged portion 25 is provided on the end face of this swinging arm 24.

Furthermore, one end of the vertical feed arm 26 is pivotally connected to the shaft end E of the vertical feed shaft 17, and one end of a T-shaped vertical feed member 27 is pivotally connected to the other end of the vertical feed arm 26 using a pin 28. There is.

Then, a portion of the vertical member 29 of the vertical feed section +827 located above the pin 28 is pivotally connected to the rising section 16 by a vertical feed link 30, so that the vertical feed link 30 and the vertical feed arm 26 These form a parallelogram, and the vertical feed member 27 is vertically moved up and down.

Further, a feed dog receiver 31 projecting from the swinging arm 24 side E is rotatably and horizontally attached to the upper end of the vertical member 29.

Further, the horizontal member 32 of the vertical feed section O 27 is made to protrude toward the vertical feed shaft 17 side, and the lower end of a vertical feed operating arm 33 extending in the vertical direction is pivotally attached to the end thereof.

The upper end of this vertical feed operation arm 33 is provided with the feed dog receiver 31.
The operating shaft 34 is fixed by passing through it horizontally so that the operating shaft 34 is fixed in a horizontal direction, one end of the operating shaft 34 is fitted into the two prongs 25 of the swinging arm 24, and one end of the ten feed dogs 35 is connected to the other end. It is pivoted.

This feed dog base 35 rests on the feed dog receiver 31,
A protruding portion 36 with a feeding dog a fixed on the upper surface and protruding from one end.
and a locking piece 37 fixed to the machine frame 1] The end of the coil spring 38 is locked so that the feed dog base 35 is always in contact with the feed dog receiver 311.

In addition, numeral 36 in the figure is a rotary shaft driving gear to which the lower shaft 4l is fixed.

The embodiment of the present invention is constructed as described above, and the horizontal feed rod 12, which is connected to the horizontal feed cam 5 and connected to the rotating lower shaft 4 by the driving source of the sewing machine (not shown), adjusts the feed. It horizontally reciprocates within a range corresponding to the movement of the feed adjustment arm 9 and the feed adjustment link 11 determined by the instrument axis 8.

This reciprocating motion of the horizontal feed iron 12 is caused by the horizontal feed link 1
3 to the horizontal feed member 20.

Since this horizontal feed member 20 is attached to the vertical feed shaft 17, it swings around the vertical feed shaft 17, and the swing arm 24 swings around C as shown by the arrow ε in FIG. let

This oscillation causes the feed dog a to horizontally reciprocate via the operating shaft 34 inserted into the two-pronged portion 25.

On the other hand, the vertical feed actuating arm 19 that engages with the vertical feed cam 61 of the lower shaft 4 rotates the vertical feed shaft 17 in forward and reverse directions.

Now, when the maximum eccentric part of the vertical feed cam 6 (see Fig. 5) is engaged with the contact part 18 of the vertical feed operating arm 19, {this is the vertical feed link via the old lower feed arm 26. 3
0, the vertical feed member 27 is raised in the vertical direction, and the feed dog a is positioned at the highest position.

At this time, the vertical feed operation arm 33 is also raised at the same time, and the operation shaft 34 is also positioned at the highest position, so that the feed dog a is raised horizontally.

Then, the swinging action of the swinging arm 24 horizontally moves the feed dog a (see FIGS. 6 and 2A) via the operating shaft 34.

On the other hand, when the contact portion 18 is engaged with the minimum eccentric portion of the vertical feed cam 6, the vertical feed member 27 is vertically lowered and located at the lowest position, and the operating shaft 34 is also located at the lowest position. Then, by swinging the swinging arm 24, the feed dog a is horizontally moved to the lowest position (see FIG. 2A).

Therefore, the feed dog a supports the feed dog receiver 3
1 and the operating shaft 34 are simultaneously raised and lowered to move the operating shaft 34 horizontally, so that the feed dog a can be moved horizontally in close contact with the cloth surface.

Since the present invention has the above-described structure and operation, the feed dog a rises in a horizontally lying position, and moves horizontally in close contact with the fabric surface while maintaining the horizontally lying position, thereby ensuring reliable feeding of the fabric. , %E It does not cause wrinkles even in thin fabrics.

[Brief explanation of the drawing]

FIG. 1A is an explanatory diagram showing the motion locus of a conventional feed dog, B is a sectional view showing the relationship with the cloth, and FIG. 2A is a diagram showing the motion locus of the feed dog of the cloth feed mechanism in the sewing machine according to the present invention. Explanatory drawing, B is a sectional view showing the relationship with the cloth, FIG. 3 is a perspective view of the main part, FIG. 4 is a side view showing only the horizontal movement relationship, FIG. 5 is a side view showing only the vertical movement relationship, FIG. 6 shows a large side view showing the compound motion. In addition, in the figure, a is the feed dog, 4 is the lower shaft, 5 is the horizontal feed cam,
6 is a vertical feed cam, 12 is a horizontal feed rond, 13 is a horizontal feed link, 14 is a feed base, 17 is a vertical feed shaft, 20
24 is a horizontal feed member, 24 is a swinging arm, 25 is a two-pronged part, 26 is a vertical feed arm, 29 is a vertical feed member, 30 is a vertical feed link, 31 is a feed dog receiver, 33 is an operating arm, and 34 is an operating shaft ,
35 is a feed dog base.

Claims (1)

[Claims] 1 Horizontal feed cam 5 driven by the drive source of the sewing machine
and a lower shaft 4 on which a cam 6 for vertical feeding is attached, and a vertical feeding shaft 1 supported by a feed base 14 that rotates by a vertical feeding operating arm 19 having a contact portion 18 at its tip abutted against the cam 6 for vertical feeding.
7 and the horizontal feed rod 1 which is combined with the horizontal feed cam 5l.
2, one end of which is pivotally connected to the horizontal feed link 13 and the other end of the horizontal feed member 20 that is pivotally connected to the vertical feed shaft 17, and a swing arm 24 that extends upward and has a bifurcated portion 25 at the upper end; A vertical feed operating arm 33 that horizontally supports an operating shaft 34 that interlocks with the two-pronged portion 25 at its upper end;
3, a vertically moving vertically moving member 27, which is pivotably mounted on the lower end of 3 by a horizontal member 32 protruding from the center shaft, and has a feed dog receiver 31 parallel to the operating shaft 34 attached to the upper end, and the vertically moving shaft 17.
The vertical feed arm 26 is pivoted to the side opposite to the vertical feed operating arm 19 and the lower end of the seventh lower feed portion +827, and the vertical feed arm 26 is parallel to the former lower feed arm 26 on the feed base 14 and the center shaft of the vertical feed member 27. a vertical feed link 30 which is pivotally connected as shown in FIG. Sewing machine E consists of a cloth feed mechanism.