JPH0584197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for forming a buttonhole using a zigzag sewing machine, and more particularly to a method for forming a keyhole-shaped buttonhole having an annular shape at one end.

(Prior Art) One example of a method for forming keyhole-shaped buttonholes using a conventional zigzag sewing machine is to use a machine with a feed adjuster because the feed directions are different for the left overlock stitch and the right overlock stitch. This has the disadvantage that the stitches of the left and right overlock stitches become unsightly due to the cumulative errors that occur. Another example is that when the left and right overlock stitches are sewn in the same direction, half of the annular part formed at one end of the keyhole shape is sewn, so if the seams of the left and right overlock stitches are separated, a gap will be created. In any case, it was quite difficult to obtain buttonholes with a beautiful finish.

(Problems to be Solved by the Invention) The present invention provides a buttonhole that is obtained by a zigzag sewing machine and that makes the stitch pitch of the left and right overlocking stitches the same and that there is no gap between the left and right overlocking stitches. It is intended to form a

(Means for Solving the Problems) The present invention forms a button hoe using a zigzag sewing machine, and in order to make the stitch pitch of the left and right overlocks the same, the left and right overlock stitches are fed in the same direction. By sewing and applying zigzag stitching to the joining portions of the left and right overlock stitches, it is possible to prevent gaps from forming at the joining portions.

(Function) The present invention is capable of creating zigzag stitches by using a zigzag sewing machine to swing a needle bar with a needle attached to its lower end from side to side, and to rotate a thread loop catching device in synchronization with the vertical movement of the needle. A device equipped with a function works together with the cloth feed movement of the feed dog to move the cloth to one side for both the left and right overlock stitches of the buttonhole, and the cloth is moved to the other side by a straight stitch that interrupts the swinging of the needle. The buttonhole is sewn by continuously combining the stitching process and the process of reinforcing the joining parts of the left and right overlock stitches.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 2. A is an arm machine frame of a sewing machine, and a drive shaft (not shown) is rotatably supported on the arm machine frame. has been done. Reference numeral B designates a needle bar having a needle C fixed to its lower end, which is moved up and down in conjunction with the rotation of the drive shaft, and is also allowed to make appropriate amplitude movements in the lateral direction. D is a bed machine frame of the sewing machine, which is integrally connected to the arm machine frame A. In the bed machine frame, a horizontal fully rotating thread ring catcher E is rotated in synchronization with the vertical movement of the needle bar B, and the thread ring catcher E is rotated in synchronization with the vertical movement of the needle bar B.
The upper thread carried by the upper thread is captured by a tip formed at one end of the outer periphery and intertwined with the lower thread of a lower thread bobbin (not shown) supported inside to form a lock stitch.

Further, the stitch forming mechanism forms a zigzag stitch by vibrating the needle bar in the lateral direction and moving the fabric forward or backward using a feed dog (not shown).

To form a buttonhole using such a zigzag seam forming device, first mark 1, 2 to 7, 8 on the center line of the longitudinal slit F to be formed in the center of the completed keyhole-shaped buttonhole. The first step is formed by moving the needle forward and backward while adjusting the amplitude of the needle, and then the 8th step of the step
Starting from the seam 9, 10 to 11, 12, 13,
A second step of the darning part connected to the semicircular annular part at one end, indicated as 14, is formed on one side of the slit F by feeding in one direction, and then a seam is formed on the other side of the slit F. A third step from 16 to seam 18 is formed by straight stitching by feeding in the other direction.

Next, from the stitch 18 to the stitch 19 at the same position as the stitch 1 of the first step, to the stitch 2.
The fourth step of the darning part, which has a semicircular annular part formed at one end leading to number 6, is sewn on top of the straight stitch of the third step by feeding in one direction in the same way as the second step, and finally and a fifth step extending from the seam 27 to the seam 30 so as to straddle the other ends of the overlocking portions of the fourth step and the second step.
After sewing the bartack part of the step, perform a few tacking stitches in the right places in the overlock stitch to complete all steps of the buttonhole.

Since the buttonhole forming method using the zigzag sewing machine of the present invention is as described above, both the left and right overlock stitches are performed by feeding in one direction, so there is no pitch error between the left and right overlock stitches. It is possible to sew with uniform stitches, and reinforcing stitches such as bartacks can be applied to the seam of the left and right overlock stitches, that is, the semicircular annular portion formed at one end, and the other end, respectively. Because of this, a strong buttonhole stitch will be sewn. Furthermore, even when an automatic buttonhole presser is used, the buttonhole according to the present invention is constructed by inserting a stitch with a small feed pitch in a part of the straight stitch in the third step to ensure detection by the buttonhole positioning sensor. It was made so that it could be done.

As stated above, the present invention uses a new method to form buttonholes, and has a great practical effect in that the stitches on both overlocked portions are uniform and both ends are strongly sewn. be.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an external view of a zigzag sewing machine embodying the present invention, and FIG. 2 is a plan view showing the order of formation of the present invention.

Claims (1)

[Claims] 1. A buttonhole in which a bartacking part is sewn to the other ends of the left and right overlocking parts connected by an annular part at one end, and a slit part is formed between the left and right overlocking parts. In the forming method, a step is formed on one side by feeding in one direction, and a step is formed on the other side by feeding in the opposite direction to the step. a step of straight stitching, a step formed by feeding in one direction a darning part connected to a semicircular annular part formed at one end on the other side, and darning parts formed on both sides of said one and the other. Before carrying out the step of forming a bartacking part by spanning both the overlocking parts at the other end, and the step of forming the overlocking part on one side, the semicircular annular parts on one and the other side are A method of forming buttonholes using a zigzag sewing machine, which comprises a step in which a buttonhole is formed at a planned connection position while changing the amplitude by feeding in one direction and the other direction. 2 The feed amount of the first few stitches of the straight sewing steps formed on the other side is smaller than the feed amount of subsequent stitches. A buttonhole forming method using a zigzag sewing machine according to item 1.