EP2028310A2 - Sewing machine - Google Patents

Abstract

The automat (1) has a sewing machine (22), a work piece transporting device for transporting a work piece (2) during sewing, and a stitch guiding device. The stitch guiding device comprises a guiding link and a guiding element that is guided to the guiding link. The guiding link is fixedly connected to a work piece supporting plate (3), and the guiding element is fixedly connected to the transporting device. The guiding element is guided to the link at two different guiding distances in two guiding positions for producing respective stitches.

Description

The invention relates to a sewing machine for sewing two mutually parallel seams in sewing material.

An automatic sewing machine of the type mentioned is known by public prior use. When sewing two seams running parallel to one another in sewing material, the problem arises in sewing machines that care must be taken to ensure that the sewing material does not warp during the sewing process even by very small amounts relative to a sewing material transport device. Such double seams are often produced in known sewing machines with two-needle machines. This leads to the outer seam having longer stitches than the inner seam, which is undesirable for reasons of optical stability and thread retention.

It is an object of the present invention to develop a sewing machine of the type mentioned in such a way that it is ensured that the material is practically not distorted relative to the fabric transport device during sewing. A further object of the invention is to avoid that attached to the fabric additional components such as a zipper closing body affect neither the fixing nor the transporting of the fabric during the sewing process.

This object is, as far as the avoidance of a delay of the material, according to the invention solved by a sewing machine with the features specified in claim 1. As regards the avoidance of impairment by attached to the fabric additional components, the object is achieved by a sewing machine with the features specified in the characterizing part of claim 10.

According to the invention, it has been recognized that a seam guiding device with a guide body displaceable between two guide positions makes it possible to use one and the same guide slot for sewing the two seams running parallel to one another (double seams). According to the invention, the guide slot between two guide positions relative to the then not necessarily hubverlagerbar executable guide body between the two guide positions can be displaced in the same way. In particular, when sewing the two seams, it is not necessary to change the relative position of the material to be transported to the material to be sewn. This prevents that such a change leads to a fabric delay. The two seams are inventively sewn sequentially, with only one sewing needle is used. The seams can then both be sewn with a constant stitch length, so that an optimum stitch length in terms of holding strength and yarn consumption can be used.

A rolling off according to claim 2 guide body leads to a safe, reproducible and low-wear guide during the sewing of the two seams. About the outer diameter of the two guide body sections, the positions of the two seams to be sewn are defined relative to each other.

An embodiment of the guide body according to claim 3 is inexpensive and particularly suitable when large lot sizes to be sewn with the same seam spacing.

An alternative embodiment according to claim 4 allows in particular a continuous adjustment of the guide body and thus a plurality of guide positions, each in the exact seam position differ. In this way, double seams with adjustable variable distance of the two mutually parallel seams can be realized.

A beveled contact surface according to claim 5 leads to a flat contact of the conical body with the contact surface of the guide slot. This reduces the wear of the guide elements. For a given stability, the guide elements can be made of less hard material.

A pneumatic drive according to claim 6 is robust and inexpensive. In particular, when an embodiment of the seam guiding device is selected with a cone-shaped guide body, a drive is selected, which allows a plurality of guide positions. For such a drive is particularly suitable a stepper motor. A pneumatic drive with several intermediate stops is also possible.

A pressure bar according to claim 7 leads to a secure holding the fabric during the sewing process. The risk of a fabric delay is eliminated.

This is especially true for a slot design of the pressure bar according to claims 8 and 9.

The object mentioned at the outset is, as far as the avoidance of impairment by attached to the fabric additional components, solved by a sewing machine with the features specified in claim 10.

Such a design prevents the additional component fixed on the sewing material from undesirably hanging on the groove in the sewing material support plate during transport through the material handling device. This cause of a possible fabric delay is thus eliminated. Such a design of a sliding body can also be used independently of the hubverlagerbaren guide body discussed in connection with claim 1, since the advantages of the sliding body of which the seam guiding device with the guide body are independent.

A ramp according to claim 11 leads to an edge-free transition of the groove bottom to the fabric support plate. This prevents snagging of the additional component even when the sliding body is not fully raised at the moment when the additional component passes the ramp.

A double-acting cylinder according to claim 12 is robust, compact and inexpensive.

Fig. 1

einen Nähautomaten zum Nähen zweier parallel zueinander verlaufender Nähte in einem Nähgut, dargestellt in einer Ausgangsstellung, in der das Nähgut auf eine Auflageplatte aufgelegt und positioniert ist, in einer Ansicht von oben;

Fig. 2

den Nähautomaten in einer sich an die Ausgangsstellung anschließenden Momentanstellung, wobei eine Nähgut-Haltekralle in eine Fixierstellung für das Nähgut verlagert ist;

Fig. 3

den Nähautomaten in einer sich hieran anschließenden Momentanstellung, wobei zusätzlich eine Ausgleichsklammer dargestellt ist, die zum Halten des Nähguts längs der zu erzeugenden Nähte in eine Klammerstellung verlagert ist;

Fig. 4

perspektivisch und im Vergleich zur Fig. 3 vergrößert die Ausgleichsklammer;

Fig. 5

den Nähautomaten in einer sich an die Momentanstellung nach Fig. 3 anschließenden Momentanstellung mit der Ausgleichsklammer in einer Innennaht-Nähposition;

Fig. 6

vergrößert und perspektivisch einen Ausschnitt des Nähautomaten im Bereich eines als Führungskörper dienenden Rollensatzes kurz vor Erreichen der Nähposition nach Fig. 5;

Fig. 7

perspektivisch einen in der Nähgut-Auflageplatte des Nähautomaten in einer Auflageplattennut versenkten Schiebekörper in einer abgesenkten Stellung;

Fig. 8

in einer zu Fig. 7 ähnlichen Darstellung den Schiebekörper nach Fig. 7 in einer angehobenen Stellung, in der die Auflageplattennut durch den Schiebekörper so ausgefüllt ist, dass dieser die ihn umgebende Nähgut-Auflageplatte stufenfrei fortsetzt;

Fig. 9

den Nähautomaten in einer Momentanstellung, die sich an die Momentanstellung nach Fig. 5 anschließt, nach dem Vernähen einer Innennaht im Nähgut;

Fig. 10

den Nähautomaten in einer Momentanstellung, die sich an die Momentanstellung nach Fig. 9 anschließt, zu Beginn des Vernähens einer Außennaht im Nähgut;

Fig. 11

in einer zu Fig. 6 ähnlichen Darstellung den Führungskörper kurz vor dem Erreichen der Außennaht-Anfangsstellung nach Fig. 10;

Fig. 12

den Führungskörper in einer vergrößerten perspektivischen Ansicht.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

Fig. 1

a sewing machine for sewing two mutually parallel seams in a fabric, shown in a starting position in which the fabric is placed and positioned on a support plate, in a view from above;

Fig. 2

the sewing machines in an adjoining the starting position instantaneous position, wherein a sewing material holding claw is displaced in a fixing position for the sewing material;

Fig. 3

the sewing machines in an adjoining instantaneous position, wherein in addition a compensation clip is shown, which is displaced to hold the material along the seams to be produced in a stapling position;

Fig. 4

in perspective and in comparison to Fig. 3 increases the balance bracket;

Fig. 5

the sewing machines in one to the momentary employment after Fig. 3 subsequent instantaneous adjustment with the compensation clamp in an inner seam sewing position;

Fig. 6

enlarged and perspective a section of the sewing machine in the area serving as a guide body roller set shortly before reaching the sewing position Fig. 5 ;

Fig. 7

in perspective, a sliding body sunk into the fabric bed of the automatic sewing machine in a support plate groove in a lowered position;

Fig. 8

in one too Fig. 7 similar representation of the sliding body after Fig. 7 in a raised position, in which the support plate groove is filled by the sliding body so that it continues step by step the sewing material support plate surrounding it;

Fig. 9

the sewing machine in a momentary position, which is based on the momentary position Fig. 5 connects, after sewing an inner seam in the fabric;

Fig. 10

the sewing machine in a momentary position, which is based on the momentary position Fig. 9 connects, at the beginning of sewing an outer seam in the fabric;

Fig. 11

in one too Fig. 6 similar representation of the guide body shortly before reaching the outer seam start position after Fig. 10 ;

Fig. 12

the guide body in an enlarged perspective view.

A sewing machine 1 is used for sewing two seams running parallel to one another in a sewing material 2. The seams to be sewn to the sewing machine 1 are two parallel and curved seams, ie a double seam, for sewing a zipper a trouser outer fabric.

Fig. 1 shows the sewing machine 1 in a starting position after the positioned placement of the fabric 2 on a fabric support plate 3. The fabric 2 is aligned in a known manner via a stop body 4 and possibly a light curtain not shown in the drawing and positioned on the support plate 3 , For fixing the Nähguts 2 in the starting position to Fig. 1 serves a holding claw 5, the fabric 2 in the in the Fig. 2 illustrated Fixierstellung in the area of a waistband of the material 2 against the support plate 3 is stuck. The Fig. 1 shows the retaining claw 5 in a non-clamping rest position.

For temporary planar fixation of the material 2, a plurality of rows of suction holes 6, which are executed in the support plate 3, with a vacuum source in combination, so that in the starting position, in the Fig. 1 is shown, the fabric 2 is sucked flat on the support plate and thus fixed.

For transporting the material to be sutured 2 during the sewing of the two seams is a fabric transport means in the form of a compensating bracket 7, for the sake of clarity in the Fig. 1 and 2 not shown. The Fig. 3 shows the balancing clamp 7 in a stapling position in which the balancing clamp 7 clamps the fabric 2 along the trainees seams against the support plate 3. For this purpose, a pressure bar 8 of the compensating bracket 7, which in detail in the Fig. 4 is shown. The pressure bar 8 has in the region of the waistband of the sewing material 2 a plurality of arranged in a row Klemmfüßchen 9, which are biased independently of each other via associated springs 10 against the fabric 2. When in the Fig. 4 illustrated embodiment, a total of fifteen Klemmfüßchen 9 are available. The Klemmfüßchen 9 ensure, for example, due to different thicknesses or due to a different number of fabric layers uneven fabric for height compensation and despite the unevenness for a uniform clamping force exerted by the pressure bar 8 on the fabric 2.

In the pressure bar 8, a slot 11 is executed. An inner edge 12 of the slot 11 follows the course of the trainee 2 trainee inner seam. An outer edge 13 of the slot 11 follows the course of the sewing material 2 trainees outer seam. The Klemmfüßchen 9 clamp the fabric 2 through the slot 11 of the pressure bar 8 through, in a region of the elongated hole 11 which is spaced from a bent portion of the pressure bar 8.

The slot 11 has transversely to the seam to be sewn seam of the inner and the outer seam in the fabric 2 a width which is greater than the distance of the parallel seams to be produced from each other. At the same time, this width of the oblong hole is smaller than twice the distance between the two parallel seams to be produced from each other.

Fig. 3 shows the compensating bracket 7 after its displacement from an elevated release position in the stapling position. The sewing material 2 is then fixed relative to the compensating bracket 7. In the position of the sewing machine 1 after Fig. 3 is the retaining claw 5 raised back to the neutral position. The stopper 4 is from the stop position to Fig. 1 in the Fig. 3 shifted upwards to a rest position.

A guided drive 14 allows a displacement of the compensating clamp 7 parallel to the support plate 3 in both the x and y direction of the in the Fig. 3 shown Cartesian coordinate system. The x-direction runs in the Fig. 3 to the left. The y-direction runs in the Fig. 3 downward.

In the support plate 3 a along the x-direction groove 15 is executed. In this groove 15 runs in the displacement of the compensating clamp 7 with the fabric 2 from the staple position Fig. 3 in a sewing position Fig. 5 a closing body of the zipper to be connected to the sewing material via the seams.

The bottom of the groove 15 is formed by a sliding body 16 (see. Figs. 7 and 8). Fig. 7 shows the sliding body 16 in a lowered position in which the groove 15 is formed, in which therefore the sliding body 16 forms the bottom of the groove 15. Fig. 8 shows the sliding body 16 in a raised position in which the sliding body 16, the groove 15 fills in such a way that the sliding body 16 continues the surrounding him sewing material support plate 3 stages. To convert the sliding body 16 between the lowered and the raised position is a double-acting lifting cylinder 17. The latter is connected at one end to the sliding body 16 and the other end to a fixedly connected to the support plate 3 base 18. The cylinder 17 is arranged lying in the base body 18. In the extended position of the cylinder 17 (see. Fig. 7 ) is the sliding body 16 in the lowered position. Obliquely extending guide slots 19, which are executed in the base body 18, provide a guide of the displacement movement of the sliding body 16 between the lowered and the raised position, wherein the raised position of the sliding body 16 in the retracted position of the cylinder 17 is present. In the displacement between the extended and the retracted position, the cylinder 17 is pivoted about a pivot joint 20 which is provided at the location of the fixing of the cylinder 17 on the base body 18 by a pivot angle which is about 10 °.

In the momentary settings of the sewing machine 1, which in the Fig. 1 to 3 are shown, the sliding body 16 in the lowered position, so that the closing body of the zipper dipping into the groove 15 and can not interfere with the fixing of the fabric 2 by the balance bracket 7.

A sewing head 21 of a sewing machine 22 of the automatic sewing machine 1 is provided with stitch forming tools, in particular a sewing needle and a gripper, a stitch formation region 23 of the support plate 3, which in the Fig. 5 indicated by dashed lines. In the stitch formation area 23, a stitch plate (not visible in the drawing) with a stitch hole is inserted into the support plate 3.

An end of the groove 15 facing the stitching region 23 has a ramp 24, so that this end opens in a ramp shape into the sewing material support plate 3 surrounding the groove 15. The ramp 24 therefore ensures, during transport of the sewing material 2, a trouble-free running of the zipper closing body out of the region of the groove 15.

When relocating the balance bracket 7 together with the fabric 2 from the clip position to Fig. 3 to the sewing position Fig. 4 at the same time the slider 16 is transferred from the lowered to the raised position. This ensures that the zipper closing body does not get caught on the support plate 3 during this transport displacement by the compensating clamp 7. A delay of the sewing material 2 when moving to the sewing position Fig. 5 is thus excluded.

In the sewing position after Fig. 5 The sewing machine 22 begins with the sewing of the inner seam, starting from the bent end of this.

To guide the curved seam course serves a seam guiding device 25, which in the Fig. 6 and 11 is shown in a perspective cutout. The seam guiding device 25 has a guide slot 26 with a leading edge 27, which is bent in accordance with the curved seam shape of the inner and the outer seam. As another guide element the seam guide device 25 next to the guide slot 26 is a guide body 28. The guide slot 26 is rigid with the fabric support plate 3 and the guide body 28 is rigidly connected to the compensating bracket 7.

Fig. 12 shows the guide body 28 enlarged in detail. The guide body 28 comprises a small guide roller 29 as the first guide section for producing the inner seam. The latter is mounted rotatably about a vertical axis 30 via a needle bearing 31. Axially in the direction of the axis of rotation 30 offset down to the small guide roller 29, the guide body 28 has a second, large guide roller 32. This is also rotatably mounted about the rotation axis 30 via a further needle bearing 33. A shaft extending along the axis of rotation 30 around which the rollers 29 and 32 rotate is extended into an outer sleeve 34 of the guide body 28 via a shaft extension 35. The shaft extension 35 is mounted axially via bearing bushes 36 in the outer sleeve 34. An anti-rotation 34a for the outer sleeve 34 is formed as non-rotatably connected to the outer sleeve 34 rib. This rib engages in a corresponding groove of a frame-fixed carrier for the guide body 28 a.

The guide body 28 is hubverlagerbar between two guide positions. The Fig. 6 shows a first of these two guide positions of the guide body 28 for generating the inner seam. The Fig. 11 shows the second guide position of the guide body 28 for producing the outer seam. In this second guide position, the guide body 28 is displaced upwardly relative to the first guide position. This displacement is effected by a pneumatic cylinder 37, the working piston with the shaft extension 35 is sheared and tensile strength connected. about an air connection 38 is the working cylinder 37 with a compressed air source, not shown, in fluid communication.

Fig. 6 shows the guide body 28 during transport of the material 2 by the compensating clamp 7 shortly before reaching the first guide position for generating the inner seam. In this position Fig. 6 the small guide roller 29 comes into contact with a switching lug 39, which is arranged upstream of the guide slot 26 and is spring-loaded against the guide body 28 on the guide slot 26. Due to the contact of the small guide roller 29 with the switching lug 39, a switching signal is triggered when the switching lug 39 retracts in the direction of the guide slot 26, which signals the transport movement of the compensating clamp 7 from the position Fig. 3 in the position Fig. 5 decelerates from a first, higher transport speed to a second, lower transport speed. This braking ensures that the small guide roller 29 comes sufficiently soft with the guide slot 26 in reaching the first guide position in contact.

Fig. 9 shows the sewing position at the end of the sewn inner seam. During the sewing of the inner seam, the small guide roller 29 is unrolled on the guide edge 27 of the guide slot 26. The seam course of the inner seam follows the inner edge 12 of the elongated hole 11 at a small distance, so that a distortion of the material 2 during the sewing of the inner seam is excluded.

After sewing the inner seam, the compensating clamp 7 transports the sewing material 2 substantially in the negative x-direction with a raised sewing needle back into one in the Fig. 10 illustrated sewing position "beginning outer seam". The compensating clamp 7 transports the material 2 so far in the negative x-direction that the switching lug 39 relative to the guide link 26 can move out again. Subsequently, the pneumatic cylinder 37 is actuated, so that now the large guide roller 32 comes to rest at the level of the leading edge 27. It is therefore set the second guide position of the guide body 28 for sewing the outer seam. This position of the guide body 28 is in the Fig. 11 shown. Now, with the compensating clamp 7, the sewing material 2 is displaced again in the positive x-direction, with the switching lug 26 engaging the guide link 26 ensuring that this displacement movement takes place in a braked manner, as already explained in connection with the first guiding position.

When the large guide roller 32 comes into contact with the leading edge 27 of the guide slot 26, which is in the Fig. 10 shown sewing position "beginning outer seam" reached. Subsequently, the large guide roller 32 rolls on the guide edge 27, wherein the compensating clamp 7 moves the material 2 in the positive x-direction and due to the curved course of the outer seam in the negative y-direction. Due to the larger outer diameter of the large guide roller 32 in comparison to the small guide roller 29 of the guide body 28 is guided in the second guide position for generating the outer seam at a greater guide distance to the guide slot 26 as in the first guide position for generating the inner seam. The course of the outer seam follows at a small distance from the outer edge 13 of the elongated hole 11, so that during the sewing of the outer seam, a delay of the Nähguts 2 is prevented relative to the compensating clamp 7.

After sewing the outer seam sewing the zipper part to the fabric 2 is completed and the fabric 2 is, for example, by a blast of compressed air, ejected.

In an alternative embodiment of the guide body 28, a cone-shaped body 40 is provided in place of the two guide rollers 29, 32, whose outer contour in the Fig. 12 indicated by dashed lines. By Hubverlagerung over the working cylinder 37 of the conical body 40 comes to rest with a different outer diameter portion of the guide edge 27 of the guide slot 26. Depending on the diameter of the currently applied to the leading edge 27 portion of the cone-shaped body 40, the transverse position of the stitched when rolling the cone-shaped body 40 on the guide slot 26 seam changes. In this way, this transverse position can be adjusted continuously via the stroke position of the conical body 40. Instead of a pneumatic working cylinder 37, the guide body 28 can be displaced with the conical body 40, for example via a stepper motor.

In the embodiment of the guide body 28 with a conical body 40, moreover, preferably the guide edge 27 is beveled at an angle which is complementary to the cone angle of the conical body 40 of the guide body 28. In this way, it is ensured that the conical body 40 when rolling on the leading edge 27 comes into contact with this area.

Claims (12)

Sewing machine (1) for sewing two seams running parallel to one another in a sewing material (2). with a sewing machine (22), with a fabric transport device (7) for transporting the sewing material (2) during the sewing, - With a seam guide device (25) with a guide slot (26) and a guide body (28) as guide elements, wherein the guide body (28) on the guide slot (26) is guided to specify a seam shape, wherein one of the guide elements (26) rigidly a fabric support plate (3) and the other of the guide elements (28) is rigidly connected to the fabric transport means (7), - wherein the guide body (28) - Hubverlagerbar is between at least two leadership positions and - Is guided in the first guide position for generating the first seam at a first guide distance to the guide slot (26) and - Guided in the second guide position for generating the second seam in a second, compared to the first larger guide distance to the guide slot (26). Sewing machine according to Claim 1, characterized in that the guide body (28) is designed as a body rolling on the guide slot (26), wherein in the first guide position a first section (29) of the guide body (28) with a smaller outside diameter and in the second, axially opposite the first guide position along a rotational axis (30) of the guide body (28) hubverlagerten guide position, a second portion (32) of the guide body (28) having a larger outer diameter for engagement with the guide slot (26). Sewing machine according to claim 2, characterized in that the first portion of the guide body (28) as a first roller (29) with a smaller outer diameter and the second portion of the guide body (28) is designed as a second roller (32) with a larger outer diameter. Sewing machine according to claim 2, characterized in that the two sections of the guide body (28) are axially spaced areas of a cone-shaped body (40). Sewing machine according to claim 4, characterized in that the conical body (40) on a contact surface of the guide slot (26) abuts against this, which is chamfered at an angle which is complementary to the cone angle of the conical body (40) of the guide body (28) , Sewing machine according to one of claims 1 to 5, characterized by a pneumatic drive (37) for converting the guide body (28) between the at least two guide positions. Sewing machine according to one of claims 1 to 6, characterized in that the material to be conveyed (7) comprises a pressure strip (8) for clamping the material, which comprises at least one sewing edge (12, 13) whose course follows the seam. Sewing machine according to claim 7, characterized in that the sewing edge (12, 13) is part of a slot (11) whose course follows the course of the seam. Sewing machine according to claim 8, characterized in that the slot (11) transversely to the seam has a width which is greater than the distance of the two parallel seams to be generated from each other and smaller than twice the distance between the two parallel seams to be produced from each other. Sewing machine according to one of claims 1 to 9, characterized by a sewing material support plate (3) with a groove (15) extending along a transport direction, - A sliding body (16), the in a lowered position forms the bottom of the groove (15), - In a raised position, the groove (15) fills in such a way that the sliding body (16), the surrounding him sewing fabric support plate (3) continues step-free. Sewing machine according to Claim 10, characterized in that the end of the groove (15) facing a stitch formation region (23) of the sewing machine (22) opens out in the form of a ramp (24) into the surrounding sewing material support plate (3). Sewing machine according to claim 10 or 11, characterized by a double-acting cylinder (17) for converting the sliding body (16) between the lowered and the raised position.

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