EP1278903B1 - Sewing device - Google Patents

Description

The invention relates to a sewing device with a programmable electronic control device for sewing pleats and darts.

In known such sewing devices, the sewing material is usually first with the help of a folding tool, which is provided on the front side with a replaceable and adapted to the stitching seam guide tongue, transported to a transfer position, temporarily fixed there and then held by lowering a pressure bar by this. The feed of the material is then then by the longitudinal and, if necessary, also in the transverse direction and also with respect to their shape adapted specifically to the seam pressure bar. It is stitched as close as possible to the pressure bar along, so that the pressure bar can be moved in a transverse thrust movement only away from the sewing needle to the outside.

A disadvantage of these known sewing devices, inter alia, that when changing the desired seam course not only the corresponding seam program must be changed, but also the form of the respective seam shape dependent parts (pressure bar and guide tongue) must be replaced. In addition, additional mechanical adjustments must be made when changing the Nähgutdicke, because in the known devices, the removal of the sewing needle depends on the Nähgutfaltkante of the Nähgutdicke.

From DE-GM 71 16 976 a sewing device with a driven in its longitudinal direction stencil rail is known, consisting of a pressure bar for the fabric and off a guide rail is made, which is in constant contact with a contact held by a carrier guide means to execute the dependence on the shape of the guide strip sideways, the longitudinal movement superimposed movements. Even with this known sewing device therefore not only the corresponding seam program has to be changed when changing the desired seam course, but also the shape-dependent parts of the respective seam (guide bar) are exchanged.

The same applies to the known from the publications DE 42 34 968 C1 and DE 40 31 200 A1 sewing devices with a driven in the longitudinal and transverse direction Nähguthalter. These sewing cloth holders serving for stitching pockets each have a sewing slot corresponding to the seam shape. Since the material holder frictionally engages the pocket on both sides of the sewing slot, it is entrained without distortion in any direction of transport in an unchanged alignment position.

When making darts in which the seam always ends at an acute angle to the Nähgutfaltkante, this must be free. For this reason, it is not possible to use the fabric holder enclosing the seam to be formed for holding and guiding fabric to be provided with darts.

From DE-PS 1660 839 a sewing unit for making darts is also known, which is a movable between a receiving position and a transfer position for the sewing folding tool, a resilient Falthilfsblech, holding means in the form of a needle bar for the folded dart and a pressure rail for the acquisition of The folding tool is adjustable in its angular position relative to the pressure rail to achieve a certain Abnähertiefe. The folding tool pushes forward during its forward movement of the fabric under the resilient Faltsilfsblech and the raised pressure rail through so far that the dart protrudes on the back of the pressure rail, depending on the preselected angular position of the folding tool, ie according to the desired Abnähertiefe. At the end of the feed movement of the folding tool, the needle bar is moved downward, with their needles seize the fabric in the area of the fold and fix it on a Nähtischplatte.

This document is, however, no indication to be taken by which means the end of the advancing movement of the folding tool is determined, for example, by any stops or by the end point of the feed path of the drive means for the folding tool. In this case, the exact determination of the end of the feed movement of great importance, because by the position or the distance of the end point of the feed movement of the folding tool to the needle of the sewing machine, the intersection of Abnähernaht is determined with the Nähgutfaltkante. Only if the end stitches of the seam shortened for the purpose of seam protection have the required distance to the sewing material folding edge is the desired quality result achieved. If the said distance is too large, the dart instead of a sharp point forms an ugly-looking funnel-shaped depression. However, if the distance is too small, the darning length is too short and it fall part of the shortened end stitches to the outside, which has the consequence that the seam is not sufficiently secured.

German patent application DE 100 11 162.9 discloses a sewing apparatus with a sewing machine, a folding tool movable between a receiving position and a transfer position for the sewing material, and a pressure strip for taking over the folded material and guiding the material during the sewing process the supply movement of the folding tool are provided in the transfer position, which lie in the movement path of the part of the folded edge of the folding tool surrounded by the folded material. By thus arranged stop means is achieved that at unchanged position of the stop means the outside of the Nähgutfaltkante always has the same distance to the sewing needle both thin and thick material. In this sewing apparatus, therefore, irrespective of the respective material thickness and without any corrective measures, the actual point of intersection, e.g. a darning seam, with the outside of the Nähgutfaltkante always exactly together with the desired intersection.

The invention has for its object to provide a sewing device of the type mentioned in which can be dispensed with a change of sewing program on a change of form-dependent parts (guide tongue, pressure bar) and in spite of a change in the Nähgutdicke additional mechanical settings not required are.

This object is achieved by the features of claim 1. Further, particularly advantageous embodiments of the invention disclose the dependent claims.

The invention is based on a device of the type described in DE 100 11 162.9 and dispenses with the use of a guide tongue depending on the shape of the seam and a pressure bar which is dependent on the shape. Rather, the supply of the sewing material is carried out only with a folding tool with a straight fold and the support and guidance of the material in the sewing process by means of a rectilinear pressure bar, wherein the electronic control device is programmed so that the desired seam course exclusively by superposition of longitudinal and transverse movements the pressure bar results.

In order to sew the largest possible number of different seam courses with the sewing device according to the invention, it has proven to be advantageous not to sew directly on the pressure bar along, but to choose the mean distance between the sewing needle and the pressure bar over known devices larger, so that the pressure bar can perform both movements to the outside and to the sewing needle out. In order to avoid the problems possibly arising when pulling out the sewing needle, designed as a Schwebefuß hold-down is located in the sewing needle, which is located just above the Nähgutfaltkante and holds the fabric when pulling out the needle and tightening the Fadenverknotung, but otherwise not touched.

In order to substantially shorten the changeover times of the sewing device when changing the sewing program, it is provided in a preferred embodiment of the invention that the seam parameters are programmable graphic-supported. For this purpose, the sewing device comprises a screen electrically connected to the control device, on which the respectively desired geometric seam course can be displayed. In the control device also preferably standard seam programs are stored. When changing a seam program, the respective new seam program is called up by a corresponding key press and the seam course is displayed on the screen.

If parameters of the illustrated seam program have to be changed, the corresponding new parameters are entered via a keyboard connected to the control device. All parameters of a seam course are defined as length measures.

To avoid the formation of bulges of the material in the axial and radial direction, it has proved to be advantageous if the Schwebefuß both on its folding edge of the material facing side of an opening wedge-shaped course and on its the direction of movement of the material opposite end face an oblique Faltkante of the sewing material has decreasing course.

In a further embodiment of the invention, the hold-down is not attached to the sewing machine of the sewing device according to the invention, but at one of the transverse movements of the pressure bar with exporting part. As such a part, in particular the roller carrier of the pressure bar transversely to the longitudinal direction displacing drive has proven to be suitable. Through the co-movement of the blank holder in the transverse direction, it can be formed over a large area so that it covers the fabric area between the pressure bar and the fabric edge during the entire sewing process and thereby keeps flat. Buckling, as they can often occur in fixed to the sewing machine down device especially towards the end of the respective sewing process by the large between hold-down and pressure bar existing distance, therefore omitted in this case.

In another embodiment of the invention is provided for the distortion-free transport of the sewing material on the pressure bar to arrange a transversely projecting pressure finger whose bottom is aligned with the underside of the pressure bar. As a result, the pressure bar comprises an L-shaped sewing area. Preferably, the Druckfmger has a wedge-shaped cross-section, so that the seated at the beginning of the sewing process on the pressure finger hold-down slides with progressive sewing jerk-free from the pressure finger.

• Fig.1 die perspektivische Ansicht einer erfindungsgemäßen Nähvorrichtung mit einer Nähmaschine, an welcher ein Niederhalter befestigt ist, und einer Tastatur- und Bildschirmeinheit;
• Fig.2 eine vergrößerte Ansicht der in Fig.1 dargestellten Nähvorrichtung im Bereich des Niederhalters mit durch eine gestrichelte Linie angedeutetem Nähgut;
• Fig.3 und 4 eine Draufsicht und eine Seitenansicht auf den in Fig.2 dargestellten Niederhalter;
• Fig.5 ein schematisches Blockschaltbild der elektronischen Steuereinrichtung mit angeschlossener Tastatur- und Bildschirmeinheit;
• Fig.6 eine Vorderansicht der Tastatur- und Bildschirmeinheit mit einem grafisch dargestellten Nahtprogramm;
• Fig.7-10 Bildschirmansichten von vier unterschiedlichen Standard-Nahtprogrammen;
• Fig.11 die perspektivische Ansicht eines zweiten Ausführungsbeispieles der erfindungsgemäßen Nähvorrichtung;
• Fig.12 eine vergrößerte perspektivische Ansicht der Antriebe der Druckleiste, der in Fig.11 wiedergegebenen Nähvorrichtung mit Druckleiste und Niederhalter;
• Fig.13 und 14 zwei Draufsichten auf die in Fig.12 dargestellte Antriebsanordnung bei unterschiedlichen seitlichen Stellungen der Druckleiste und
• Fig.15 einen Schnitt durch die in Fig.13 dargestellte Anordnung entlang der dort mit XV-XV bezeichneten Schnittlinie.

Further details and advantages of the invention will become apparent from the following with reference to figures explained embodiments. Show it:

• 1 is a perspective view of a sewing device according to the invention with a sewing machine, to which a hold-down is attached, and a keyboard and display unit;
• 2 shows an enlarged view of the sewing device shown in Figure 1 in the region of the blank holder with indicated by a dashed line sewing material.
• Figures 3 and 4 are a plan view and a side view of the downholder shown in Figure 2;
• 5 shows a schematic block diagram of the electronic control device with connected keyboard and display unit;
• 6 is a front view of the keyboard and display unit with a graphically displayed seam program;
• Fig.7-10 screen views of four different standard seam programs;
• 11 is a perspective view of a second embodiment of the sewing device according to the invention;
• FIG. 12 shows an enlarged perspective view of the drives of the pressure bar, the pressure bar and hold-down device shown in FIG. 11; FIG.
• Figures 13 and 14 are two plan views of the drive arrangement shown in Figure 12 at different lateral positions of the pressure bar and
• 15 shows a section through the arrangement shown in FIG. 13 along the section line labeled XV-XV there.

In Fig. 1, numeral 1 denotes a sewing apparatus for sewing pleats and darts with one a table 2 arranged electric sewing machine 3 and a programmable electronic control device 4. On the table 2, a folding tool 5 is further arranged with a straight folding edge 6, which is arranged displaceably from a receiving position into a transfer position for the workpiece. Further, located on the table 2 is a rectilinear pressure bar 7 for holding and guiding the material to be sewn during the sewing process, which can be moved by means of corresponding drives 8, 9 in the longitudinal and transverse directions.

The sewing device 1 further comprises a holding device 10 with stop means for limiting the feeding movement of the folding tool 5 in the transfer position and for temporarily fixing the material provided with the fold, and a screen keyboard unit 12 arranged on a pivoting arm 11.

The electric sewing machine 3, the screen keyboard unit 12, the drives 8, 9 for the pressure bar 7 and the drives 13, 14 for the holding device 10 and the folding tool 5 are electrically connected to the control device 4 (Figure 5). The structure of the screen keyboard unit 12 is Fig.6 again. These keys are so-called softkeys.

On the sewing machine 3, a hold-down 16 designed as a floating foot is fastened in the area of the sewing needle 15 (FIG. 2), which is merely shown as a dot-dash line and whose connection with the sewing machine 3 is not shown in detail for reasons of clarity. In order to avoid the formation of bulges of the sewing material 17 indicated by dashed lines when sewing in the axial and radial directions, the floating foot 16 has an oblique path decreasing towards the folding edge 19 of the sewing material (FIG. 3) as well as on its end face 18 opposite the direction of movement of the sewing material 17 its the folding edge 19 of the material 17 facing side 20 an opening wedge-shaped course (Figure 4).

The mode of operation of the sewing device according to the invention will be explained in more detail below. Initially, regardless of the desired Nahtverlauf- the fabric is moved in a conventional manner to form the desired fold by means of the folding tool 5 from a receiving position to a transfer position and there with the help the holding device 10 fixed by lowering of holding needles. Subsequently, the folding tool 5 moves back into its receiving position. The pressure bar 7 lowers to the fabric and now holds the fabric while the holding needles are moved up and release the fabric.

If not already done, the desired seam program (for example for a darts) can now be set. For this purpose, by means of a corresponding key, e.g. set shown in Figure 7 and designated 25 seam course. This seam course then appears graphically on the screen 21 of the screen keyboard unit 12. By pressing the number keys 22, the parameters of the seam course can be changed. The variable values are: the dart depth 1 ', the dart length 2' and the curvature 3 '. In addition, other values such as program number, stitch length, seam additions, etc. can also be entered via the keyboard and displayed on the screen 21. After pressing the "Enter" key 23, the programmed values are transferred to a corresponding memory 24 of the control device 4 (FIG. 5) and the sewing process is initiated. After completion of the sewing process, the pressure bar 7 releases the fabric 17 and returns to its original position, so that a new material can be fed by means of the folding tool 5.

It has been found that the majority of the darts and pleats occurring in practice can be programmed by the four basic shapes shown in FIGS.

8, the seam course 26 of a further dart is shown. The variable values in this case are: the darning depth 1 ", the darts length 2", the waist depth 3 ", the waist length 4", the first curvature 5 "and the second curvature 6".

9 shows the seam course 27 of a pleat fold with variable first pleat fold depth 1 '", pleat pleat length 2"', second pleat fold depth 3 '"and curvature 4' ''.

10 likewise shows the seam course 28 of a pleat fold with variable first pleat depth 1 ^IV , first pleat pleat length 2 ^IV , second pleat fold depth 3 ^IV , second pleat pleat length 4 ^IV , third pleat fold depth 5 ^IV , first bend 6 ^IV and second bend 7 ^IV .

After entering all the values determining the respective seam course, a plausibility check of the data is carried out by the control device. If they lead to an inadmissible seam, the incorrectly indicated value is displayed on the screen keyboard unit 12.

Further, unusual seam shapes can be achieved through free programming. In the sewing field that can be moved by the sewing device (for example 250 × 30 mm), any desired seam course is possible.

The invention is by no means limited to the embodiment described above. Thus, for example, Figures 11-15 an embodiment in which a hold-down 30 is provided, which is not attached to the sewing machine 3, but on a roller carrier 31. Der Haltering 30 ist in der Zeichnung dargestellt. This leads the again indicated 7 pressure bar and is connected to the second drive 9, so that it participates in the transverse movements of the pressure bar 7. Through this co-movement of the blank holder 30 in the transverse direction, it can be formed over a large area so that it covers the sewing field 32 between the pressure bar 7 and folding edge 19 of the material 17 (Fig.13) during the entire sewing process and thereby keeps flat.

The effect caused by the longitudinal movement of the pressure bar 7 effect, according to which a moment effect occurs in the fabric, which promotes buckling of the material, therefore, makes much less noticeable in the large-area hold-down 30 when using the described in connection with Figs.1 and 2 hold-down 16th

The corresponding arrangement of the blank holder 30 on the roller carrier 31 is apparent in particular from Fig.12. In this case, the pressure bar 7 is arranged laterally pivotable about an axis of rotation 34 displaceable by the drive 8 in the longitudinal direction, wherein the lateral pivoting movement to achieve the planar sewing field 32 (Fig.13) by means of the second drive 9. This drive 9 acts via the roller carrier 31 with the rollers 35 on the pressure bar 7, which can be guided on the one hand between the rollers 35 in the longitudinal direction and on the other hand can be pivoted transversely to the longitudinal direction.

In connection with the rotatable mounting of the pressure bar results from Fig.14 apparent special effect that due to the different radial distance R1 and R2 between the rotation axis 34 and the rollers 35 on the one hand and the hold 30 on the other hand present at the beginning of the sewing very small Distance between the pressure bar 7 and hold-down 30 in the course of the sewing process is noticeably larger, but without exposing the corresponding area of the fabric to a significant extent. The increase in the distance generated in the same manner as in the downholder 16 shown in Figures 1 and 2, a transversely directed tensile force. Although this tensile force is significantly smaller than that which occurs when using the blank holder 16, it can still exert a noticeable smooth drawing effect, since the bulges of the material under the blank holder 30 are considerably flatter than the bulges between the blank holder 16 and the pressure bar 7 can train.

Another contribution to the distortion-free transport of the sewing material is a arranged on the pressure bar 7, transversely projecting, relatively short pressure finger 36 whose bottom is aligned with the underside of the pressure bar 7. As is apparent from Fig. 13, the pressure bar 7 and the pressure finger 36, the sewing field 32 L-shaped.

The pressure finger 36 has a wedge-shaped cross section (FIG. 15). As a result, the hold-down 30 seated on the pressure finger 36 at the beginning of the sewing process can slide off the pressure finger 36 smoothly as the sewing progresses.

LIST OF REFERENCE NUMBERS

1

suturing device

2

table

3

sewing machine

4

control device

5

Faltwerkzeug

6

fold

7

print bar

8.9

drives

10

holder

11

swivel arm

12

Screen keyboard unit

13.14

drives

15

sewing needle

16

Downholder, Schwebefuß

17

workpiece

18

Front side (floating foot)

19

Folding edge (sewing material)

20

Side (Schwebeffuß)

21

screen

22

number keys

23

Enter key

24

Storage

25-28

seam courses

30

Stripper plate

31

roller carrier

32

sewing area

34

axis of rotation

35

role

36

pressure fingers

1 ', 1 "

dart depth

1 ''', 1 ^IV

first waist depth

2 ', 2 "

dart

2 '' '

Pleat length

2 ^IV

first pleat length

3 '

curvature

3 "

waist deep

3 ''', 3 ^IV

second waist depth

4 ''

waist length

4 '' '

curvature

4 ^IV

second pleat length

5 "

first curvature

5 ^IV

third bundle depth

6 "

second curvature

6 ^IV

first curvature

7 ^IV

second curvature

Claims (13)

1. Sewing device with a programmable electronic control system (4) for sewing folds and tucks with the features:

   a) the sewing device (1) comprises a sewing machine (3) with a sewing needle (15) and with a holding-down device (16; 30), with a folding tool (5), which can be moved between a receiving position and a transfer position for the fabric (17), stop means for limiting the feed motion of the folding tool (5) in the transfer position, a holding means (10) for the fold or tuck formed, and a pressure pad (7) for taking over the folded fabric (17) in the transfer position and for guiding the fabric (17) during the sewing operation;

   b) the pressure pad (7) has a straight design independently from the seam format;

   c) to obtain a flat sewing field (32), the pressure pad (7) is arranged movably in the longitudinal direction by a first drive (8) connected to the control system (4) and in the transverse direction by a second drive (9) connected to the control system (4);

   d) the control system (4) can be programmed such that the particular desired seam course (25-28) can be obtained exclusively by the superimposition of the longitudinal and transverse movements of the pressure pad (7), wherein both movements away from the sewing needle (15) and movements toward the sewing needle (15) are possible;

   e) the holding-down device (16; 30) is designed as a floating foot that holds the fabric flat at least in the area of the sewing needle (15).
2. Sewing device according to Claim 1, characterized in that the pressure pad (7) is arranged laterally pivotably around an axis of rotation (34) that can be displaced in the longitudinal direction by the first drive (8), so that the pressure pad (7) is displaced laterally during its movement in the longitudinal direction by the second drive (9) to obtain the flat sewing field (32).
3. Sewing device according to Claim 1 or 2, characterized in that the holding-down device (30) is arranged at a part that also participates in the transverse movement of the pressure pad (7).
4. Sewing device according to Claim 3, characterized in that the second drive (9) is connected to a roller carrier (31), whose rollers (35) guide the pressure pad (7), and the holding-down device (30) is fastened to the roller carrier (31).
5. Sewing device according to Claim 3 or 4, characterized in that the width of the holding-down device (30) is selected to be such that it approximately covers the entire area between the pressure pad (7) and the folded edge (19) of the fabric (17) during the sewing operation.
6. Sewing device according to Claim 1 or 2, characterized in that the holding-down device (16) is fastened to the sewing machine (3).
7. Sewing device according to one of Claims 1 to 6, characterized in that the floating foot (16) has an opening, wedge-shaped course on its side (20) facing the folded edge (19) of the fabric (17).
8. Sewing device according to one of Claims 1 to 7, characterized in that the floating foot (16) has an oblique course decreasing toward the folded edge (19) of the fabric (17) on its front side (18) located opposite the direction of movement of the fabric (17).
9. Sewing device according to one of Claims 1 to 8, characterized in that a transversely projecting pressing finger (36), whose underside is flush with the underside of the pressure pad (7), is arranged at the pressure pad (7).
10. Sewing device according to Claim 9, characterized in that the pressing finger (36) has a wedge-shaped cross section, such that the holding-down device (30) seated on the pressing finger (36) at the beginning of the sewing operation slides off from the pressing finger (36) without a jerk as the sewing progresses.
11. Sewing device according to one of Claims 1 to 10, characterized in that the sewing device (1) includes a display screen (21), which is connected to the control system (4) and on which the particular desired geometric seam course (25-28) can be displayed.
12. Sewing device according to Claim 11, characterized in that standard seam programs, whose seam courses (25-28) can be displayed on the display screen (21), are stored in the control system (4), and that the parameters (1'-7^IV) associated with the particular seam course (25-28) can be changed by means of a corresponding keyboard.
13. Sewing device according to Claim 11 or 12, characterized in that all parameters (1 ' -7^IV) of a seam course (25-28) are defined as length measurements.

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