EP1130150A2 - Sewing device for producing folds and darts - Google Patents

Abstract

A sewing unit for folding and sewing end seams has a pneumatically driven (12) folding knife (14) that moves a folded fabric (N) under a sewing machine (3). The movement (B) of the knife (14) is limited as the edge of the fabric fold (NK) contacts an end stop (22). The distance (D) between the end stop (22) and the sewing machine needle (5) is adjustable, e.g. by a threaded spindle. Exact shaping of the folded edge is assisted by guide plates (24, 25), which are spring loaded to accommodate different thicknesses of fabric. Preferred Features: The end stop (22) and guide plates (24, 25) together with retaining pins (29) are mounted together on a common slide.

Description

The invention relates to a sewing unit according to the preamble of Claim 1.

From DE-PS 1 660 839 is a sewing unit for the manufacture of Darts known. The sewing unit contains a between a receiving position and a transfer position for the folding tool that can be moved, a resilient folding auxiliary sheet, holding means in the form of a Needle bar for the folded dart and a pressure rail for Takeover of the folded sewing material and for guiding during the sewing process. The folding tool is in its angular position relative to the Adjustable pressure rail to achieve a certain dart depth. The folding tool pushes the material in under its forward movement through the resilient folding auxiliary sheet and the raised pressure rail so far that the dart on the back of the pressure rail protrudes, depending on the preselected angular position of the folding tool, d. H. according to the desired dart depth. At the end the needle bar becomes after the feed movement of the folding tool moved downwards, with their needles sewing material in the area of the fold grasp and fix on a sewing table top.

There is no indication in the publication of what means the end of the feed movement of the folding tool is determined whether for example by any attacks or by the end point the feed path of the drive means for the folding tool. It is the exact determination of the end of the feed movement of large Importance, because of the location or the distance of the end point of the Feed movement of the folding tool to the needle of the sewing machine is the The point of intersection of the dart seam with the material folding edge is determined. Just if the shortened end stitches of the seam for the purpose of securing the seam have the required distance to the edge of the material to be sewn, that will desired quality sewing result achieved. Is the said distance too large, the dart forms one instead of a sharp point ugly looking funnel-shaped depression. But the distance is too small, the dart length becomes too short and part of the shortened end stitches in free, which means that the seam is not is adequately secured.

DE 295 14 185 U1 is a sewing unit for the manufacture of Folding and darts known, in which the folding tool resiliently a rotatable stop disc, through which the folding or Dart depth is adjustable. What is special about this adjustment device for the folding tool is that the stop washer has stepless control curve and a stepper motor is finely adjustable. This way, when you switch from thin to thick or vice versa from thick to thin material Deviation of the actual intersection of the dart seam with the outside the sewing material folding edge corrected from the target intersection become. Although through this known adjustment device Carrying out such a correction is very simplified still the need, if necessary, such a correction to have to do at all. Furthermore, it is still necessary sew at least one sample piece to be able to check whether the chosen correction value was sufficient.

The invention is therefore based on the object of handling a still trained according to the preamble of claim 1 sewing unit to further simplify. The task is characterized by the Feature of claim 1 solved.

By the measure, the sling gear for limiting the Feed movement of the folding tool in the movement path of the folded material surrounding part of the folding edge of the folding tool and to be arranged directly in the path of the material folding edge achieved that the path length of this feed movement from the material itself is influenced, with the position of the sling unchanged the outside of the fabric folding edge for both thin and thick material is always the same distance from the needle, while the folding tool by the measure of the respective thickness of the sewing material in to a certain extent self-adjusting in front of the stop bar Stand comes. This ensures that regardless of the respective material thickness and without any corrective measures the actual point of intersection of the dart seam with the outside of the material folding edge always coincides exactly with the target intersection.

To achieve different dart depths is according to claim 2 and 3 the distance of the stop bar to the needle can be changed.

By the folding auxiliary strips specified in claims 4 and 5 a particularly exact formation of the material folding edge and thus the Darts achieved.

The development according to claim 6 ensures that the Stop bar with the folding auxiliary bars and the holding means always have a constant mutual distance and that is why also in this regard when processing sewing material of different thickness no distance corrections are necessary.

Fig. 1

eine Teilansicht einer Näheinheit;

Fig. 2

einen vergrößerten Ausschnitt aus Fig. 1, in dem die Anschlagleiste und zwei Falthilfsleisten dargestellt sind;

Fig. 3

eine vergrößerte Teilansicht der Näheinheit mit in Ausgangsstellung befindlichem Faltlineal das ein Nähgutteil trägt;

Fig. 4

eine noch stärker vergrößerte Teilansicht der Näheinheit mit in Faltstellung befindlichem Faltlineal, und

Fig. 5 und 6

je einen vergrößerten Ausschnitt aus Fig. 4, in dem die Situation bei der Verarbeitung von unterschiedlich dickem Nähgut dargestellt ist.

The invention is explained with reference to an embodiment shown in the drawing. Show it:

Fig. 1

a partial view of a sewing unit;

Fig. 2

an enlarged section of Figure 1, in which the stop bar and two folding auxiliary bars are shown.

Fig. 3

an enlarged partial view of the sewing unit with the folding ruler in the starting position carrying a workpiece;

Fig. 4

an even more enlarged partial view of the sewing unit with folding ruler in the folded position, and

5 and 6

4 each shows an enlarged detail from FIG. 4, in which the situation when processing sewing material of different thickness is shown.

The sewing unit has a table top 2 carried by a frame 1 on. On the table top 2, a sewing machine 3 is arranged, the one contains up and down movable needle bar 4 with a needle 5.

In a known manner, the sewing unit has the shape of the one to be produced Seam determining pressure rail 6 on between two Rollers 7 can be passed. The pressure rail 6 and the rollers 7 are movable up and down with the help of two pressure cylinders 8. By not Drive means shown is the pressure rail 6 in its longitudinal direction slidable, whereby, as already mentioned, between the Rollers 7 is moved through.

A guide rail 9 for a slide 10 is on the frame 1 attached. The piston rod 11 of an air cylinder engages on the slide 10 12 on. On the sled 10 is an upward projecting carrier 13 attached to which is parallel to the table top plane extending plate-shaped folding ruler 14 is arranged is. The edge of the folding ruler 14 facing the pressure rail 6 forms a folded edge 15.

On a bracket 16 attached to the table top 2 is a Guide rail 17 attached, which in turn a carriage 18, wearing. The carriage 18 is connected to a threaded spindle 19 Positioning motor 20 in drive connection.

A rod 21 with an L-shaped cross section is attached to the slide 18, whose horizontally extending leg is transverse to the movement path B the folding edge 15 of the folding ruler 14 extending stop bar 22 for the folding ruler 14 forms. On the stop bar 22 is one of the abutting surface 23 projecting flat in the vertical plane Folding auxiliary bar 24 is formed. On the top of the stop bar 22, a second folding aid strip 25 is arranged. she is in vertically and is moved by a spring mechanism 26 pressed against the stop bar 22.

On the carriage 18, a compressed air cylinder 27 is arranged, the Piston rod a holding bar running parallel to the stop bar 22 28 for a plurality of holding needles 29 carries. The holding needles 29 are corresponding in the upper folding aid bar 25, not shown through holes assigned.

In the folding ruler 14 are one of the number of in a known manner Holding needles 29 corresponding number of passage slots, not shown formed for the holding needles 29, which differ from the Extend folding edge 15 starting transversely to this.

It works as follows:

The operator places the sewing material N on which, for. B. a dart to be formed on the one in the starting position Folding ruler 14 according to FIGS. 1 and 3, with part of the sewing material N hangs over the folded edge 15.

By acting on the compressed air cylinder 12, the folding ruler 14 under the raised pressure rail 6 and the raised holding needles 29 moved into the transfer position shown in Fig. 4. The sewing material N forms a U-shape around the folded edge 15. As soon as that Folding ruler 14 with the part of the sewing material N surrounding the folding edge 15 into the space between the two auxiliary folding strips 24, 25 occurs, due to the braking effect of the folding auxiliary strips 24, 25 in the sewing material N along the folding edge 15 an exactly shaped darts fold formed and the adjacent sewing material area smoothed. The one there Folded edge formed in the sewing material N is denoted by NK.

As soon as the folding ruler 14 with the folding edge 15 folded material N on the stop surface 23 of the stop bar 22 abuts, this prevents a continuation of the feed movement.

5 and 6 between the stop surface 23 and the Needle 5 of the sewing machine 3 is parallel to the path of movement B Folded edge 15 of the folding ruler 14 measured distance D. This distance D remains unchanged until a by the positioning motor 20 other distance D is set. In contrast, changes depending on the Thickness of the material N the distance d between the folded edge 15 and the Stop surface 23. Figures 5 and 6 show the corresponding Differences for thick and thin material N. For thick material the folding ruler 14 remains by the dimension d1 corresponding to the material thickness and with thin sewing material by the correspondingly smaller dimension d2 before Stop surface 23 stand. In contrast, the one at the Stop surface 23 on the outside of the material folding edge NK regardless of the respective sewing material thickness, always the unchanged Distance D to the needle 5 at.

After completion of the feed movement through the folding ruler 14 by actuating the compressed air cylinder 27, the holding needles 29 in the Sewing material N is lowered, which makes it easier when the Folding rulers 14 is held securely. Then the print bar 6 moved in the longitudinal direction to the sewing machine 3 and then this switched on, whereupon the dart seam is formed.

Because the sewing material edge NK is independent of the respective material thickness always has the distance D to the needle 5, the intersection of the Sewing seam with the sewing material folding edge NK always at the desired location lie and thus in an arbitrarily repeatable way an exact trained darts manufactured.

Claims (6)

Sewing unit for making folds and darts with one Sewing machine (3), one between a receiving position and one Transfer position for the folding tool (14) which can be moved, which has a folded edge (15), with a stop means for Limiting the feed movement of the folding tool (14) in the Transfer position, with holding means (29) for the fold formed or the dart and with a pressure rail (6) to take over of the folded sewing material in the transfer position and for guiding of the sewing material during the sewing process, characterized in that that the stop means (22) in the path of movement (B) of the folded part of the folded material (15) of the Folding tool (14). Sewing unit according to claim 1, characterized in that the Slings of one essentially transverse to the trajectory (B) the folding edge (15) of the folding tool (14) extending Stop bar (22) formed and parallel to the path of movement (B) the folded edge (15) of the folding tool (14) measured distance the stop bar (22) to the needle (5) of the sewing machine (3) is changeable. Sewing unit according to claim 2, characterized in that the Stop bar (22) via a threaded spindle (19) with a Positioning device (20) is in drive connection. Sewing unit according to one or more of claims 1 to 3, characterized in that the stop bar (22) at least a folding auxiliary bar (24; 25) connected to it is assigned, which are essentially horizontal and also transverse to Movement path (B) of the folded edge (15) extends. Sewing unit according to claim 4, characterized in that the Stop bar (22) two spaced apart has superimposed folding auxiliary strips (24, 25), of which the upper with the help of a spring mechanism (26) in one Is held in the rest position from which it is retracted Folding tool (14) between the two folding auxiliary strips (24, 25) can be moved upwards. Sewing unit according to claim 4 and 5, characterized in that the stop bar (22) with the folding auxiliary bars (24, 25) and the holding means (29) for the fold formed on one common rail-guided slides (18) are arranged, which is connected to the threaded spindle (19).

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