JPH0543752Y2 - - Google Patents

Description

[Detailed description of the invention] A. Field of industrial application The present invention relates to a cloth feed control device for a sewing machine, and in particular, when sewing a curved part of the edge of cloth with a sewing machine, the curved edge is moved to the point where the sewing machine's needle is placed. In order to continuously change the feeding direction of the fabric so as to feed the fabric, the needle location of the fabric is shifted a certain distance from the feeding direction in order to give a moment to the needle location of the fabric. The present invention relates to a cloth feed control device for a sewing machine, which is equipped with a pressing means that presses the cloth at a location where the moment is centered.

B. Prior Art FIG. 1 is a plan view of the vicinity of a needle 1 of a sewing machine.
The edge of the cloth to be sewn is fed by a cloth feed plate 2 of the sewing machine in the direction indicated by the arrow through a needle 1 that moves vertically (in a direction perpendicular to the plane of the paper in FIG. 1). As long as the edge of the fabric is straight, the fabric may be fed straight in the direction of arrow F, but if the edge is curved, the feeding direction of the fabric must be bent.

Therefore, in the prior art, the cloth is pressed at a point shifted a certain distance to the side from the direction in which the cloth is fed on the needle 1, and a moment is applied to the cloth at the needle 1 with this point as the center of moment.

For example, in FIG. 1, a portion of the cloth that is deviated by a certain distance from the direction in which the cloth is fed on the needle 1 is pressed by a pressing body such as a ball 3, for example. Then, a moment is applied to the needle 1 of the fabric, centering on the area pressed by the ball 3 and having an arm defined by the distance from this pressing area to the needle 1, thereby bending the feeding direction of the fabric (first (in the case of the illustrated example, to the right). This is how the subsequent curved edges are sewn.

C. Problems to be Solved by the Invention Such conventional cloth feed control devices are only suitable for sewing curved edges having a relatively large radius of curvature corresponding to the length of the moment arm.

D. Means for Solving the Problems Therefore, the present invention provides a fabric feed control device for a sewing machine as described at the beginning of this detailed description, in which the pressing means includes at least two pressing bodies, one of which To provide a cloth feed control device in which one pressing member is set closer to the needle than the other pressing member.

E. Effect According to the present invention, when sewing a curved edge with a relatively large radius of curvature, the fabric is pressed with a pressing body (for example, pressing body 3 in FIG. 1) that is relatively far from the needle, and the curvature is When suturing a curved edge with a smaller radius, a second pressing body (for example, pressing body 4 in FIG. 1) that is closer to the needle also applies pressure.
Thus the moment arm length (moment radius)
is made smaller so that smaller radius curved edges can be handled. Also, a small moment radius means a large curvature, and a large force is applied to the fabric, but in this case, the fabric is pressed by two pressing bodies, so it can withstand that large force.

F. Embodiments Hereinafter, explanations will be continued based on embodiments of the present invention shown in the drawings.

First, with reference to FIG. 1, the control of, for example, the hole-shaped cloth pressing body 3 (and 4) will be explained.

This cloth feed control device is set on the feed direction line of the edge of the cloth passing through the needle 1, and has a first sensor 5 that detects the presence or absence of the edge of the cloth, and a A second sensor 6 is provided to detect the presence or absence of the curved edge.
Therefore, the following three states occur.

(i) If the edges of the fabric are straight. sensor 5
and 6 both sense the presence of the limbus. In this case, the pressing body 3 is lifted away from the surface of the cloth.

(ii) When the cloth reaches the edge. Sensors 5 and 6 both sense the absence of cloth. In this case, the sewing machine will be stopped.

(iii) When the edge of the cloth has a curved shape (in the embodiment shown in FIG. 1, it curves toward the upper right). Sensor 5 senses the absence of a fabric edge and sensor 6 senses the presence of a fabric edge. In this case, the pressing body 3 is lowered and pressed against the cloth. The pressing bodies 3 and 4 are attached to one end, that is, the tip, of a pressing body mounting member having spring properties, which will be described later.
The other end, that is, the rear end of this pressing body mounting member is attached to a driving means, which will be described later, which drives the pressing bodies 3 and 4 so as to press them against the cloth.

This lowering operation of the pressing body 3 is performed by a drive signal, which is generated only when the sensors 5 and 6 are in the third state. This driving means includes, for example, an electromagnet 7 shown in FIGS. 2 and 3;
This can be done by lowering the pressing body 3 via an interlocking mechanism which will be described later.

Similarly, regarding the pressing body 4 closer to the needle 1,
By arranging sensors similar to sensors 5 and 6 to be able to sense the presence or absence of a curved edge of smaller radius, using the same or a separate electromagnet and interlocking mechanism as the pusher 3, It can be made to rise and fall.

FIGS. 2 and 3 show the sensor 5 as described above,
The pressing body 3 is lowered by a signal from 6, and the pressing body 4, which is closer to the needle 1, is lowered by a signal from a similar sensor (not shown) (hereinafter referred to as a pair of sensors (not shown)), and the pressing body 4 is lowered against the cloth surface. The interlocking mechanism for pressing is shown. This interlocking mechanism connects the electromagnet 7 and the pressing body mounting member, and includes a slide 9, a lever 13, and a connecting bar 15.

As mentioned above, for example, the ball-shaped pressing bodies 3 and 4
are fixedly mounted on the tip of the same or separate pressing body mounting member 8 by appropriate means in the positional relationship shown in FIG. Mounting member 8 is preferably made of a spring material so as to have spring properties.

The pressing bodies 3 and 4 are the pressing body 3 which is farther from the needle 1.
From the pressing part (lower surface) of the pressing part (i.e. the pressing body used in correspondence with the curved edge part with a larger radius), the needle 1
In FIG. 2, the pressing part (lower surface) of the closer pressing member 4 (i.e., the pressing member used when the radius of the curved edge is smaller) is slightly higher, i.e. between the two lower surfaces. It is best to set it with steps as indicated by d. In this way, the pressing body 3 applies a stronger pressing force to the cloth than the pressing body 4.

The pressing body mounting member 8 is attached directly or via a mounting plate 10 to the lower end of a slide 9 that can slide up and down.

A height adjustment screw 11 is connected to the mounting spring 8 by suitable means, by means of which the height of the balls 3 and 4 can be adjusted as appropriate.

Slide 9 is biased upwardly by spring 12.

The slide 9 has a cam surface 9a at its upper end, and a roller 13a attached to the lower end of the lever 13 engages with this cam surface 9a. The upper end of the lever 13 is pivoted to a frame 14 of the mechanism.

One end of a connecting bar 15 is pivotally connected to an intermediate point between the pivot point of the lever 13 and the roller 13a, and the other end of this bar 15 is fixed to the rotational output shaft 7a of the electromagnet 7. It is pivotally connected to the swinging arm 16.

When the electromagnet 7 receives the signals emitted by the sensors 5 and 6 in the above state (), its output shaft 7a is rotated by a small angle α ₁ in the direction of arrow f (clockwise) in FIG. It is assumed that when the sensor pair (not shown) receives a signal emitted in a state corresponding to (), the output shaft 7a is rotated in the same direction to a larger angle α ₂ .

In the configuration as described above, when the sensors 5, 6 sense a relatively large radius curved edge of the cloth, the rotary output shaft 7a of the electromagnet 7 rotates by an angle α ₁ , whereupon the arm 16, the connecting bar 15, Via the lever 13, the slide 9 is pressed down against the force of the spring 12, so that the pressing body or ball 3 is pressed against the fabric surface and creates a moment center.

Further, when a pair of sensors (not shown) detects a relatively small radius curved edge of the cloth, the output shaft 7a of the electromagnet 7 further rotates to an angle α ₂ , where the pressing body 3
In addition, the pressing body 4 is also pressed against the fabric surface, creating another moment center closer to the needle 1 than the moment center.

G. Effects of the Invention As is clear from the above description, according to the present invention, it is possible to sew the edge of a curved cloth with a smaller radius than before, and it is also possible to press the cloth more strongly.

It goes without saying that the overall configuration of the present invention and the shape and arrangement of each component can be modified in various ways other than the illustrated embodiment.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the area near the needle showing the arrangement of the needle and cloth pressing body of the sewing machine, Fig. 2 is a schematic side view of the fabric feed control device of the sewing machine according to the present invention, and Fig. 3 is the device shown in Fig. 2. FIG. 1... Sewing machine needle, 3, 4... Cloth pressing body, 5, 6
... Cloth detection sensor, 7 ... Electromagnet, 8 ... Pressing body mounting member, 9 ... Slide, 9a ... Cam surface,
13... Lever, 13a... Roller, 15... Connection bar, 16... Swinging arm.

Claims (1)

[Claims for Utility Model Registration] (1) When sewing a curved edge of a cloth with a sewing machine, the feeding direction of the cloth should be adjusted so that the curved edge is fed into the needle of the sewing machine. In order to change the needle continuously, the center of the moment is pressed by pressing the fabric at a position shifted a certain distance from the feed direction of the needle in order to apply a moment to the needle in the fabric. In a cloth feed control device for a sewing machine, the pressing means includes at least two pressing bodies, a spring-like pressing body mounting member with the pressing body attached to one end, and a pressing body mounting member. a driving means for supporting the other end and driving the pressing body via the pressing body mounting member so as to bring the pressing body into contact with the cloth or separating the pressing body from the cloth, the driving means for driving the pressing body through the pressing body mounting member; The sewing machine's cloth feed control device is located closer to the needle than the sewing machine. (2) The control device according to claim 1, wherein one pressing body and the other pressing body are arranged with a difference in level from each other with respect to the cloth when the cloth is not pressed.