JPS6161834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing machine having a guide device for a workpiece as defined in the preamble of claim 1.

Before sewing the parts to be sewn together, the edges of the parts to be sewn must be flattened by the sewing lady, neatly overlapped and directed through the sewing position in a direction corresponding to the desired seam. Must be. However, this only takes place in the particular area of the workpiece that lies between the sewing woman's body and the needle. After one area of parts has been sewn, the part to be sewn is released and the area of another part has to be prepared as described above and moved through the sewing position. Therefore, the sewing process often has to be interrupted. Special difficulties arise when processing knitted materials.
This is because the edges of such materials roll up and must therefore be unrolled before sewing can take place.

One device is already known from Japanese Utility Model Publication No. 54-6586, in which the layers of the workpiece to be sewn together must be unwound in front of the needle of the sewing machine. The device consists of a casing, which is designed as a hollow body. The hollow space of the casing is connected to a low pressure source. When the edge of the workpiece to be unwound by this device is fed towards the needle, it is neatly unrolled, but in order to avoid being sucked too deeply into the hollow space of the casing, the sewing woman must Continuously applying a pullback force to the layer of the workpiece in a direction opposite to and compatible with the flow of suction air, and at the same time aligning the edges of the layer of the workpiece with the desired seam line. direction must be fed towards the needle. This not only requires great skill but also concentration and can be stressful and tiring.

From West German Utility Model No. 8236844, a sewing machine having a guide device for the workpiece is already known, and this device has a funnel-shaped chamber inside one casing. This chamber is open on one longitudinal side and on two lateral sides for the passage of the article to be sewn and is bounded by a lateral guide wall having at least one guide pin projecting into the chamber. ing. This guide wall is connected via one opening to a chamber, which is connected to a low pressure source. The connecting portion with the low pressure source is located in the central part of the side of the guide wall formed by the guide pin, and is located approximately in the center between the end where the workpiece is fed into the guide device and the end where it is sent out. There is.

With the above-mentioned guide device, when the edge of the workpiece is fed, the rolled-up part is constantly unrolled, and at the same time, the edge is sent to the sewing position while contacting the guide wall, and the workpiece part is placed under a low pressure source. cannot be sucked into the passage connected to the However, there is a tendency to be sucked in.

The funnel-shaped chamber is connected to a suction hole provided on the side of the chamber at approximately half the height of the guide wall, so that it passes through the sewing material passage space and the chamber and reaches the suction hole in a radial manner. A flow of air is generated in the opposite direction, and this flow of air determines the direction of the force acting on the part to be sewn.
Therefore, in the first half of the guide device, the force acting on the workpiece has, in addition to a lateral component, a forward component directed in the feed direction of the workpiece, while in the rear half of the device, the force acting on the workpiece has a lateral component. In addition to the component directed toward the workpiece, a component directed toward the direction opposite to the direction in which the workpiece is fed in the publication acts on the workpiece. Due to the above-mentioned flow conditions, when the edge of the workpiece facing the air flow is fed to the sewing position, it is accelerated in the half on the side fed by the sewing woman and accelerated on the side fed out. It is slowed down in half of the time. The deceleration or braking of the edge section immediately in front of the sewing position can lead to undesirable deformations of the material to be sewn. Moreover, in the case of knitted materials, it is inevitable that the edges will curl up again. This is because in the area directly in front of the needle the air flows approximately parallel to the lateral guide walls.

The object of the invention as claimed in claim 1 is to improve the properties when rolling and guiding the rolled-up vines obtained according to the state of the art.

Due to the characteristic formation shown by the invention as claimed in claim 1, the layer of the workpiece is fed obliquely forward in the direction of the guide wall, at least until the needle is pierced. facing the direction of the air flow, thus ensuring that rolling up again before sewing the edges is avoided, and the guidance of the lateral edges of the layers of the workpiece being sewn at least from the side feeding into the device. It is securely attached to the correct position.

The embodiment section indicates further advantageous measures to achieve the object of the invention.

One embodiment of the invention will now be described in detail using the accompanying drawings.

The guiding device shown as an example includes a substrate 1,
It consists of an intermediate plate 2 and a cover plate 3 made of transparent acrylic glass, for example, for observing the object to be sewn. These plates 1, 2 and 3 are fastened together by screws 4.
The guide device can also be constructed as a one-piece injection molded part. In order to form a chamber 5, the intermediate plate 2 is cut out on its left longitudinal side in FIGS. 1 and 2 and is therefore approximately U-shaped. This intermediate plate has a leg 6 on the side into which the material to be sewn is fed and a leg 7 on the side from which the material to be sewn is fed, by means of which the lateral sides of the chamber 5 are closed. has been done. On the lower side of the cover plate 3, there is a
A long hole 8 extending parallel to the chamber 5 is machined above the chamber 5.

In the region of the guide device on the side into which the workpiece is fed, a chamber 5 enlarged in cross section by the elongated hole 8 is provided with a screw which is attached to the upper surface of the cover plate 3 by, for example, adhesive. A tube piece 9 screwed into the tube 10 is connected via a tube 11 to a low pressure source 12, for example a turbine or a pump. As shown, the tube piece 9 is oriented obliquely upwards in the direction of the right longitudinal side of the plates 1 to 3, so that better flow conditions inside the chamber 5 are achieved.

A sewing material passage space 13 formed between plates 1 and 3 is present on the left vertical side surface of the guide device in the figure. This sewing material passing space 13 is a chamber 15.
In contrast, the front faces 14, 1 of the legs 6, 7 of the intermediate plate 2
5 and are arranged at a distance from each other, projecting into the chamber 5 and having left-hand guide surfaces facing the front surfaces 14, 15.
It is bounded by a workpiece edge guide formed by a guide roller 16 coplanar with the material. Guide roller 16 is screwed to plates 1 and 3 by screws 17. When viewed from the guide slit 13, the cross-section of the chamber 5 is the workpiece edge guide 14/
15/16 are also made somewhat smaller by means of a flat member 18 mounted on the base plate 1, for example by means of adhesive, thus allowing less air to pass through in this area and making it easier for the sewing material to be sewn in particular. In the majority of the chamber 5 located on the side from which the material is delivered, the amount of air passing through is smaller.

In order to make it possible to bring the end of the guide device on the workpiece delivery side as close as possible to the piercing position of the needle 19 of the sewing machine, the plates 1 and 3 are arranged at 20 on the workpiece delivery side. It is retracted to the plane of the edge guides 14/15/16 of the workpiece to be sewn.
This retreated range is provided for the cutting blade of the sewing machine and the workpiece presser foot 22. 1st
The figure shows that the chamber 5 extends behind the puncture position of the needle 19.

In order to mount the guide device on the workpiece carrier plate of the sewing machine, base plate 1 has two slits 24 on its extension 23, through which the mounting screws pass.

The operating mode of the device described above is as follows. The edge of the workpiece part to be processed is first inserted into the workpiece passage space 13 from the workpiece feed side after the low pressure source 12 has been activated. Workpiece passage space 13, workpiece edge guide with hole 14/1
5/16 and the suction air flowing through the chamber 5, the edge of the workpiece part is pressed towards the workpiece edge guide 14/15/16. In the case of knitted materials, the edge is already connected to the front face 14 and the first guide roller 1 in the area where it is fed.
It is unrolled between 6 and 6. This is because this range is the range where the amount of air flow is greatest. This is achieved by the fact that the suction tube piece 9 is provided at the end of the chamber 5 adjacent to the sewing position and that the cross section of the chamber 5 extends parallel to the direction of feed of the workpiece (arrow V). Since the elongated hole 8 is provided to give the air flow an effect in the feeding direction, the sewing machine can feed the workpiece to the sewing position on the lower side of the cover plate 3. After that, they will be assisted in the subsequent process. When passing through the part of the chamber 5 whose cross-sectional area is reduced by the flat member 18, the edges of the part to be sewn are correspondingly weaker due to the reduced amount of air flow compared to the inlet part. It is subjected to a suction force, which force is just sufficient to prevent the edge of the workpiece part from rolling up again and, furthermore, the edge is moved into the workpiece edge guide 14/1.
This is sufficient to ensure contact with 5/16. This also prevents parts of the sewing material from being sucked into the chamber 5. Therefore, the sewing woman moves the workpiece material located outside the workpiece passage space 13 during feeding to the sewing position and then adjusts the length of the next workpiece part into the workpiece passage space 13. It is only necessary to infiltrate the inside of 13. The chamber 5 and the suction air passage reaching the rear of the sewing position are connected to the legs 6 and 7.
between the guide rollers of the workpiece edge guide which reach the rear of the sewing position with the front face 15 of the flat element 18 and the suction tube piece 9.
By intentionally grading the action of the air flow and influencing the direction of the air flow, by adjusting the position of the By being stronger in the area of infeed and weaker before and after the sewing position, a substantial improvement of the guiding device is achieved with respect to the flattening and guiding properties of the winding and the flattening of the part to be sewn. The cut edge is guided in a controlled manner to a location as close as possible to the piercing position of the needle 19 due to the cutting blade 21 and workpiece presser 22 necessary for cutting the edge.

For example, in order to process two workpiece parts whose edges are rolled out flat, cut and sewn together, the device shown in the exemplary embodiment can be used to create a unique workpiece for each workpiece part. object passage space,
It can have a chamber connected to a workpiece edge guide and a low pressure source 12.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the guide device relative to the sewing position of the sewing machine, and FIG. 2 is a sectional view taken along the line -- in FIG. 3... Cover plate, 5... Chamber, 8... Long hole, 9...
Pipe piece, 13...Sewn object passage space, 14/15/
16...Sewn material edge guide, 19...Needle, V...Direction of feed.

Claims (1)

[Scope of Claims] 1. It has a sewing material passing space bounded by a lateral guide wall, and the space is connected to one chamber through at least one opening provided in the guide wall. In a sewing machine having a guide device for the workpiece, the chamber is connected to one low pressure source.
at least one of the openings is located at sewing position 1 of the sewing machine.
Sewing machine with a guide device for the workpiece, characterized in that the end extending up to 9 and adjacent to the sewing position 19 has a low-pressure connection. 2. The cross-section of the chamber 5 decreases laterally by the guide wall 14/15/16 in the area adjacent to the sewing position 19 of the sewing machine and by the guide wall 14/15/1.
The cross-section of the area of the chamber 5 located on the side of 6 and remote from the workpiece passage space 13 extends approximately parallel to the workpiece feed direction (arrow V) and is connected to a low-pressure connection. 2. The sewing machine according to claim 1, wherein the sewing machine is enlarged by an elongated hole 8 provided in the cover plate 3 of the guide device. 3 The lateral side of chamber 5 is a guide wall 14/15/16
3. The sewing machine according to claim 1, wherein the sewing machine is closed to the surface extending through the sewing machine. 4. According to claims 1 to 3, the chamber 5 has a tube piece 9 pointing obliquely upward away from the guide wall 14/15/16 as a low-pressure connection. Any one of the sewing machines mentioned above.