JPH0411236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feed device such as a cycle stitch sewing machine, and more particularly, a cam body that has a cam surface as control information for operating the feed means and rotates at a reduced speed in conjunction with the main shaft of the sewing machine; It is equipped with a swinging body that swings in accordance with changes in the cam surface of the cam body, and when the sewing needle is coming out of the workpiece and rising, the feeding means is actuated based on the swinging of the swinging body to follow the planned shape. In a sewing device that forms a seam with a seam, a cam surface corresponding to the final seam of the cam body is provided on a sub-cam body that is movable and lockable in a direction intersecting the direction of movement of the cam surface with respect to the rocking body, and both cam bodies The sewing machine is characterized in that a setting position corresponding to the sewing condition is displayed, and by changing the setting position of the sub-cam body, the setting of the needle drop position related to the final stitch can be changed as appropriate.

Conventionally, as this type of sewing device, the
27660 or JP-A-50-89160 are known. And, with these sewing devices,
For example, when performing the so-called bar tack stitch shown in Figure 3, the last two stitches are irregularly dropped to prevent the stitch from fraying at the end, which is called a "knot stitch".
However, since the control of the needle drop point of each stitch, that is, the feed of the sewing device, is controlled by a cam surface formed on a single disc, there are the following drawbacks: It was hot.

In other words, if we compare the case of sewing relatively thick and stiff fabrics such as denim with cotton thread, and the case of sewing relatively weak fabrics such as wool or wool blends with synthetic fiber thread, we can see that the sewing thread is similar to the fabric and sewing thread. The frictional resistance and the penetration resistance of the needle through the cloth are greater in the former than in the latter. For this reason, the needle of the former is more likely to be bent when it pierces the fabric than the latter, and the 21st needle in Figure 3 falls in the same place as the 20th needle, causing the upper thread to be cut. When a frictional force is applied from the outside to the thread of the final stitch when removing the needle thread after cutting or using it after sewing, the stitch tends to lift up. In the former case, these phenomena occur from the needle drop point of the 20th needle to the 21st needle drop point.
The smaller the distance (feed pitch) P from the needle to the needle drop point, the more noticeable it becomes, and in the latter case, the larger the feed pitch P becomes. Therefore, if the feed pitch P is set to the optimum value for the former, in the latter case the upper thread will float and the stitch of the knotting stitch R will become frayed.On the other hand, if the feed pitch P is set to the optimum value for the latter, the needle will become loose in the former case. There were disadvantages such as needle thread falling twice in the same place, causing needle thread breakage.

It is an object of the present invention to solve the above-mentioned drawbacks of the conventional method by making it possible to change the cam surface of the cam body related to the final stitch in accordance with the sewing conditions of different combinations of sewing thread and material to be sewn. .

Embodiments of the present invention will be described below with reference to the drawings.

The sewing device 1 is a known cycle stitch sewing machine (hereinafter referred to as the sewing machine) in which starting/stopping and cloth feeding are mechanically controlled. The main shaft is interlocked via a clutch mechanism, and after a predetermined rotation of the main shaft, the clutch mechanism is released and the main shaft is stopped at the position where the needle 2 is raised to its highest position.The main shaft is generally constructed as follows.

The cam body 19 controls cloth feeding, has cam grooves in the X-coordinate direction and the Y-coordinate direction on both end faces, and rotates at a reduced speed in conjunction with the above-mentioned main shaft.

The first rocking body 3 is swingably supported on the machine frame by a horizontal shaft 4, and a roller 5 supported at one end of the first rocking body 3 is loosely fitted into a cam groove on one end surface of a cam body 19. The first moving body 7 is swingably supported on the machine frame at 6.
are connected to interlock with each other via a square piece 8,
By changing the position of the square piece 8 from the horizontal shaft 6 using the fixing means 9, the swing angle of the first series of moving bodies 7 with respect to the first swinging body 3 is changed. The lower end of the first moving body 7 is connected to a sliding body (not shown) that can freely slide along a straight line in the Y direction (left-right direction in FIG. 1) parallel to the bed plane, and furthermore, the cloth support 10 Feed table 1 placed on the top surface of the bed
1 is rotatably supported on an axis perpendicular to this sliding body. The presser foot 12 is fixed integrally with the feed table 11, and the presser feet 13, 13 are movably supported on the presser foot 12 so as to be movable up and down and lockable so as to clamp and release the cloth between them and the cloth support 10. There is.

The second rocking body 14 is swingably supported on the machine frame by a horizontal shaft 4, and a roller 15 supported at one end of the second rocking body 14 is attached to the cam body 1.
It loosely fits into the cam groove on the other end surface of 9.

The second interlocking body 16 is supported by the machine frame with a shaft perpendicular to the lower part of the bed, one end of which is connected to the other end of the second rocking body 14 via a rod 17, and the other end is connected via a pin 18. It is linked with the feed stand 11.

The relationship between the cam body 19 and the feed base 11 is such that when the cam body 19 rotates and the first rocking body 3 is rotated clockwise or counterclockwise by one of the cam grooves, the cloth support 10 moves along the Y coordinate line. When the feed base 11 moves together with the sliding body so as to move to the right or left along 1st
The feed bar 11 swings around the connecting portion with the sliding body so as to move in an arc toward or toward the paper surface of the drawing, and as a result of these combinations, the fabric held between the fabric support 10 and the presser foot 13, 13 is moved to the needle 2. The movement of the robot is controlled as desired with respect to the passage route of the vehicle.

FIG. 2 shows a cam body 19 acting on the second rocking body 14.
This is a schematic representation of a part of the cam groove 20 on one side, where the angle α is the movement period of the feed table 11 corresponding to the time when the needle 2 is coming out of the cloth, and the angle β is the period when it is stopped. It is. The long groove 21 formed in this cam body 19 extends from the second half of the movement period α corresponding to the final stitch (the 21st stitch in the example) to the movement period corresponding to the next first stitch (the first stitch in the example). The cam groove 2 of the cam body 19 over the rotation angle range up to the first half of
They are formed parallel to a radial line passing through these ranges so as to resolve 0. The long groove 21 is connected to the cam groove 20 separated by this.
A sub-cam body 19a as a changing means, which has a cam groove 20a formed with both ends wider than the width of the cam groove 20, is loosely fitted so as to be slidable along the above-mentioned straight line, and the set screw 22 is used to tighten the cam. One end of an eccentric shaft 23 fixed to the body 19 and rotatably supported by the cam body 19 is loosely fitted into the long hole 24 of the sub-cam body 19a. Further, on the upper end of the eccentric shaft 23, there are a plurality of markings P ₁ , P ₂ as information corresponding to different sewing conditions depending on different combinations of sewing thread and cloth (in this embodiment, two corresponding to cotton thread and synthetic fiber thread). is provided opposite to the stamp 0 provided on the sub-cam body 19a.

This invention has the above-described configuration, and when performing bar tacking as shown in FIG. The control of the first rocking body 3 by the other cam groove (not shown) of 19 is the vertical feed control shown in FIG.

FIG. 2 shows a state in which the eccentric shaft 23 is adapted to the sewing conditions using synthetic fiber thread, and in this case, the rotation of the cam body 19 in the counterclockwise direction in FIG. is the stop period β of the 20th needle to the 21st
When the needle (last sewing needle) reaches the stop period β, the second oscillating body 14 rotates slightly clockwise in FIG. 1 around the shaft 4, so that the cloth is sent a predetermined distance to the left in FIG. 3. . When the eccentric shaft 23 is rotated clockwise to align the markings O and _P1 , the sub-cam body 19a moves along the long groove 21 from the center of rotation of the cam body 19, as shown by the chain line in FIG. Because it moves away,
As a result, when the roller 15 advances to the stop period of the 21st stitch, the fabric is fed further to the left in Figure 3 than in the above case, and from the needle drop point of the 20th stitch to the 21st needle. The distance P to the falling point increases by a distance corresponding to the amount of movement of the sub cam body 19a.

As described above, the present invention provides a cam surface corresponding to the final seam of the cam body on the sub-cam body which can be moved and locked in a direction intersecting the direction of movement of the cam surface with respect to the rocking body, and also provides a cam surface on both cam bodies. By displaying the setting position corresponding to the sewing conditions and changing the setting position of the sub-cam body according to the display, the needle drop position related to the final stitch can be changed as appropriate. The seam pitch can be set to the optimum length with simple operations, corresponding to the sewing conditions of different combinations of sewing thread and workpiece, so even if the sewing conditions change, there will be no lifting of the upper thread or breakage of the upper thread. It is possible to make knot-free stitches, and the beauty of the seams is not lost.
Therefore, the versatility of the sewing machine and the quality of sewing products are improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the sewing machine, FIG. 2 is a partial plan view of a cam body having changing means, and FIG. 3 is a plan view of a seam.

Claims (1)

[Claims] 1. A stitch forming means that forms a final stitch through cooperation with a sewing needle that supports an upper thread and moves up and down and a shuttle that supports a bobbin thread and rotates in synchronization with the sewing needle, and a feeding means operable to move either or both in a horizontal direction;
A cam body 19 that has a cam surface as control information for operating the feeding means and rotates at a reduced speed in conjunction with the main shaft of the sewing machine, and rocking bodies 3 and 14 that rock following changes in the cam surface of the cam body. In the sewing device that operates the feeding means based on the swinging of the swinging body when the sewing needle is coming out of the workpiece to form a pattern consisting of a predetermined number of stitches along a predetermined shape, the cam body A cam surface corresponding to the final stitch is provided on the sub-cam body 19a which can be moved and locked in a direction intersecting the direction of movement of the cam surface with respect to the rocking body, and both cam bodies are provided with setting position indications corresponding to the sewing conditions. A feeding device for a sewing machine, characterized in that the needle drop position for the final stitch can be changed as appropriate by changing the setting position of the sub-cam body.