JPS6017552B2 - Upper feed mechanism of sewing machine - Google Patents

Description

[Detailed description of the invention] The present invention relates to an upper feed mechanism of a sewing machine.

As shown in Fig. 1, overlock sewing machines and the like are known to have an upper feed mechanism that feeds the cloth through four movements in cooperation with the lower feed teeth in order to improve the feed force of the cloth or to form gathers in the cloth. ing.

This upper feed mechanism has a presser foot at the tip as shown in Figure 1.
The upper feed arm 5, which is swingably supported by pin 3 and pin 4 on the presser foot arm 2 and has an upper feed dog 5A at its tip, and the pin 6 provided on the upper feed dog 5A compete with the pin 6 to Feed dog 5
It is composed of a swinging arm 7 that provides four interlocking movements to A.

Therefore, as the upper feed arm 5 rotates about the vertical axis 2A of the presser arm 2, the pin 6 comes out of the swing arm 7 and can move together with the presser arm 2 to a position away from the needle. This has the advantage that operations such as needle replacement can be facilitated.

However, since the upper feed arm 5 is connected to the swing arm 7 by a pin 6 at a portion close to the upper feed dog 5A, the load of the swing arm 7 is applied to the upper feed dog 5A.
When A moves four times, the upper feed dog 5A does not move accurately due to the inertial force due to the load of the swing arm 7, resulting in the drawback that the gathers are not formed beautifully or the seams are not uniformly aligned. .

The object of the present invention is to provide an upper feed mechanism for a sewing machine that can eliminate these drawbacks.

Hereinafter, one embodiment of the present invention will be described based on the drawings.
In FIG. 2, reference numeral 8 denotes a support stand rotatably supported on the machine frame 9 about a horizontal axis 10, 11 a first vertical shaft supported on the support stand 10 so as to be rotatable about a single vertical axis, and 12 1 is a presser arm having a base end fixedly supported on the first vertical shaft 11 and provided with a presser foot 14 having a through hole 13 at the tip; 15 is rotatably supported on the machine frame 9 and swings in conjunction with the main shaft. 16 is an upper rotating arm whose base is fixed to a horizontal shaft 17 which is rotatably supported on the machine frame 9; 18 is a connecting pestle for punching the free ends of the driving arm 15 and the upper rotating arm 16; be. Reference numeral 19 indicates a front and rear swinging arm whose base is fixed to the horizontal shaft 17 and extends the free machine downward; 20 indicates a shaft that is supported so as to be spreadable on the machine frame 9 and swings as it moves in a royal line;
Reference numeral 1 denotes a vertically swinging arm whose base end is fixed to a shaft 201 and whose free end extends horizontally, and a roller R is rotatably supported at the free end.

22 has a horizontal support part 23 at the base end, the middle part is rotatably supported by the free end of the front-back swinging arm 19, and the tip part is supported by the vertical swinging arm 21.
A rocking table 24 extending above the roller R is provided on the rocking table 22 and is a leaf spring having an elastic force that acts so as to come into contact with the roller R at all times.

The rocking table 22 is designed to perform four movements in conjunction with the main shaft by a synthetic movement of the back and forth movement of the front and back swinging arms 19 and the vertical movement of the vertical swinging arms 21. 25 is the rocking table 22
In the horizontal support portion 23, the second vertical shaft is rotatably supported on an axis substantially extending from the axis of the first vertical shaft 11.

Reference numeral 26 denotes an upper feed dog 2 whose base end is fixedly supported on the second vertical shaft 25 and whose tip is free-floating in the upper and lower through holes 13 of the presser foot 14.
It is a sending arm with 7.

Reference numeral 28 denotes a lower feed dog which moves four times in conjunction with the main shaft and feeds the cloth in cooperation with the upper feed dog 27.

Reference numeral 29 denotes a pressure regulating device that adjusts the presser pressure of the presser foot 14 and includes a spring 30 that constantly presses the upper surface of the presser foot arm 12 downward.

Also, 31 is a pressing device equipped with a spring 32 that constantly presses the upper surface of the free end of the rocking table 22 downward. As shown in FIG. 3, the rocking table 22 is rotatably supported on the front and rear swinging arms 19 by a shaft 22A, and a fork 22B is formed at the base end of the rocking table 22. The base end of the presser foot arm 12 may be rotatably supported by the second vertical shaft 25. next,
The operation of this invention will be explained. FIG. 2 shows a state in which the upper feed dog 27 and the presser foot 14 are in the sewing position facing the lower feed dog 28.

When the sewing machine is started in this state, the lower feed dog 28, which is interlocked with the main shaft, moves four times, and the driving arm 15 and the vertically swinging arm 21, which are moving with the main shaft, swing. The driving arm 15 swings through the connecting village 18 and the upper rotating arm 16 to the front and back swinging arm 19.
is transmitted to the oscillation of the The vertical motion of the vertically swinging arm 21 is transmitted to the rocking table 22 via the leaf spring 24, and the back-and-forth motion of the vertically swinging arm 19 is also directly transmitted to the rocking table 22, resulting in a synthetic movement of the vertical and longitudinal movements. causes the rocking table 22 to make four movements. The four movements of the rocking table 22 cause the feed arm 26 to make four movements, and in conjunction with this, the upper feed dog 27 makes four movements to feed the cloth in synchronization with the four movements of the lower feed dog 28. Since the four movements of the upper feed dog 27 are performed by the rocking table 22 connected to the rear of the upper feed dog 27, the load of the rocking table 22 does not act much on the upper feed dog 27, which reduces the inertia of the upper feed dog 27. The force is reduced and the upper feed dog 27 performs four movements accurately without jumping. Next, in order to replace the needle or remove cloth scraps near the needle, the upper feed dog 27 and the presser foot 14 are separated from the suture part, but the center of rotation of the feed arm 26 having the upper feed dog 27 is Since the second vertical axis 25 and the first vertical axis 11, which is the center of rotation of the presser foot arm 12, are located on almost the same parallax line, the presser foot 14 and the upper feed dog 27 are connected to each other. The needle can be rotated around the first and second vertical shafts 11 and 25 and moved away from the sutured portion, making it easier to replace the needle or remove cloth scraps. As described above, according to the present invention, the feed arm having the upper feed dog is connected to the rocking table at the rear away from the upper feed dog, so the load of the rocking table does not act much on the upper feed dog. As a result, the inertia of the upper feed dog is reduced, allowing the upper feed dog to perform four movements accurately without jumping, making it possible to form gathers beautifully and to make uniformly aligned stitches. This effect is achieved.

In addition, since the feed bowl and the presser foot arm are supported so that they can be rolled around the first and second vertical axes that are located on the same axis, the presser foot and the upper feed dog work together to perform sewing using a sewing machine. This has the effect that needle replacement and removal of cloth around the needle can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional top feed mechanism, FIG. 2 is a front view of an embodiment of the top feed mechanism of the present invention, and FIG. 3 is a perspective view of main parts of another embodiment of the top feed mechanism. . 8... Support stand, 11... First vertical axis, 12...
... Presser foot arm, 22 ... Rocking table, 26 ...
...Second vertical ball, 26...Feeding arm, 27...
...Upper feed dog, 28...Lower feed dog. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A support stand rotatably supported on the machine frame around a horizontal axis, and a presser foot that is rotatably supported around a first vertical axis whose base end is provided on the support stand and has upper and lower through holes at its tip. a presser foot arm provided with a presser foot; a rocking table supported on the machine frame so as to make four movements in synchronization with the lower feed dog that moves forward and backward relative to the throat plate in conjunction with the main shaft; A sewing machine comprising: a feed arm whose base end is supported on a second vertical shaft supported on a rocking table so as to be rotatable about an extension axis; Top feed mechanism.