JPH044704Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is designed to move the cloth presser foot that gives a feed motion to the processed cloth and the cord guide that guides the cord sewn during buttonhole sewing. The present invention relates to a sewing machine for sewing buttonholes, and in particular to a device for preventing the cord from sticking out when changing the position of the cord guide.

[Conventional technology]

Generally, when the cord is guided to the buttonhole seam position by a cord guide and the cord is sewn into the seam using the needle thread, the tip of the cord guide is You must always be ahead of the needle.

On the other hand, when sewing buttonholes, it is necessary to sew both sides of the buttonhole, and the presser foot and cord guide are controlled to reciprocate, and the cord guide position is adjusted every time the feeding direction of the work cloth changes. must be changed without interfering with the needle, and the cord guide is controlled so that its movement trajectory is as shown in FIG.

In FIG. 2, 1 indicates a work cloth and 2 indicates a buttonhole.

[Problem that the invention attempts to solve]

As mentioned above, the cord is used to reinforce the buttonhole of a shrinkable material such as knit, and must be sewn into the seam by the upper thread. However, even when the position of the cord guide is changed as shown by A and B in FIG. There is a drawback that the core string cannot follow the seam and the core string protrudes from the seam without being sewn into the seam.

In order to solve this drawback, it has been attempted to temporarily release the thread tension disc when changing the position of the cord guide, but this method has not been sufficiently effective due to frictional resistance of the cord guide path.

[Means for solving problems]

The present invention improves this point, and aims to provide a cord extrusion prevention device that can prevent the cord from protruding by improving the ability of the cord to follow the position locus of the cord guide.

In the present invention, one end is engaged with a cord locus conversion operating shaft that rises when the position of the cord guide is changed, and the other end guides the cord and loosens the cord in synchronization with the position change of the cord guide. It is characterized by having a link mechanism that can be rotated so as to be held.

[Effect]

As a result, the cord is loosened at the same time as the position of the cord guide begins to change, the cord tension due to the frictional resistance of the cord guide path is released, and the ability of the cord to follow the motion trajectory of the cord guide is improved. , there is a margin for thread feeding of the core string, and the core string is prevented from protruding from the seam.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of the main parts of an embodiment of the present invention.

In the figure, 11 indicates a needle, and 12 indicates a fabric presser plate.

Further, reference numeral 13 indicates a cord tensioner, from which the cord 15 is guided to a cord guide 16 with a predetermined tension. This cord guide 16 is supported by a support rod 17, which is connected to an actuating rod 18. Reference numeral 19 denotes a cord locus conversion operating shaft that cooperates with the support rod 17 and the operating rod 18 to change the position of the tip of the cord guide 16 as shown by A or B in FIG. These configurations are well-known configurations and are not characteristic of the present invention, so detailed explanations will be omitted.

The feature of the present invention is that one end is engaged with a cord locus conversion operating shaft that rises when the position of the cord guide is changed, and the other end guides the cord and loosens the cord in synchronization with the position change of the cord guide. It is equipped with a link mechanism that can be rotated so as to be held, and an example of this link mechanism is constructed as shown in the figure. That is, 20 in the figure indicates a bridge member fixed to the cord locus conversion operating shaft 19,
A locking plate 21 is screwed onto this piece member 20. This locking plate 21 has a cord feeding wire attachment plate 2.
The cord feeding wire mounting plate 22 is held rotatably about a swing shaft 26 by an L-shaped metal fitting 25 screwed onto the mounting plate 23 with a screw 24. A cord feeding wire 27 is screwed onto the other end of the cord feeding wire attachment plate 22 with a screw 28.
A hole 30 is formed at the tip of the cord feeding wire 27, and the cord 15 is passed through the hole 30. The end of the cord feeding wire attachment plate 22 to which the cord feeding wire 27 is attached is attached to the spring 3.
1, it is biased clockwise. The link mechanism is configured as described above.

〔motion〕

The characteristic operation of one embodiment of the present invention constructed in this way will be explained. Now, when the cord guide 16 changes its motion trajectory to the left or right as shown by A or B in FIG. start. At this time, the cord feeding wire attachment plate 22 is also pushed upward and rotated counterclockwise around the swing shaft 26,
The cord feeding wire 27 rotates downward (in the direction of arrow C). As a result, the cord 15 is forcibly pulled out from the cord tensioner 13, and at the same time as the position change of the cord guide 16 begins, the cord 15 is loosened, and the cord is stretched due to the frictional resistance of the cord guide path. This improves the ability of the cord to follow the movement locus of the cord guide 16, and prevents the cord 15 from protruding from the seam. When the position conversion of the cord guide 16 is completed and the cord locus conversion operating shaft 19 is lowered, the cord payout wire 27 returns to its initial position.

〔effect〕

As explained above, according to the present invention, when changing the position of the cord guide in a buttonhole sewing machine, the cord is forcibly pulled out from the cord tensioner to give slack to the cord. Therefore, even when the position of the cord guide is changed, it is possible to prevent the cord from protruding from the seam.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of an embodiment of the present invention. Figure 2 is a motion locus diagram of the cord guide. 11... Needle, 12... Presser foot, 13... Core cord tensioner, 15... Core cord, 16... Core cord guide, 19...
... Cord locus conversion operation axis, 20... Bridge member, 21...
... Locking plate, 22 ... Cord feed wire attachment plate, 27
... Core cord feeding wire, 30 ... Hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cord tensioner that adjusts the tension of the cord; and a cord guide that guides the cord from the cord tensioner to the buttonhole seam position. In a buttonhole sewing machine according to the present invention, one end is engaged with a cord locus conversion operating shaft that rises when the position of the cord guide is changed, and the other end guides the cord and changes the cord in synchronization with the position change of the cord guide. A cord extrusion prevention device characterized by having a link mechanism that can be rotated so as to provide slack in the cord. (2) The means has one end in contact with a cord locus conversion operating shaft that rises when the position of the cord guide is changed, the cord is guided to the other end, and the means rotates in synchronization with the position change of the cord guide. The cord extrusion prevention device according to claim 1, which is a movable cord feeding wire.