EP1321555B1 - CNC-controlled buttonhole sewing machine - Google Patents

Abstract

The traversing table (7) has split support plates (15a, 15b) and the fabric is held on both sides of the buttonhole between plates (19a, 19b) and hinged clamps (17a, 17b). One of the clamps (17b) can be moved by a small amount to spread the buttonhole. The drive is through a stepping motor and eccentric under the control of the central programming unit. <??>The clamp (17b) is displaced at right angles to the buttonhole by only half the required spreading distance while the other clamp (17a) is moved a similar amount in the opposite direction by movement of the traversing table (7). Alternatively both clamps can have a displacement drive. The clamping mechanisms are driven by pneumatic cylinders attached to the support plates (15a, 15b).

Description

The invention relates to a CNC-controlled buttonhole sewing machine according to the preamble of claim 1.

From the brochure JUKI MEB-3200 Instruction Manual no. 02 29343316 a CNC-controlled buttonhole sewing machine of the generic type is known. It has an x-y table, which is displaceable by means of two stepper motors as x-drive and y-drive in the near plane. On the x-y table two Nähgutklammern are arranged by means of which a fabric can be held on the x-y table. These are in each case displaceable mirror-symmetrically relative to a center plane in the x-direction by means of a pneumatic cylinder in the plane of intersection formed by the x-y plane. Both pneumatic cylinders can each be actuated by means of a control command stored in the control unit. On the x-y table adjusting screws are provided on each side, which allow adjusting the spreading path of each Nähgutklammer of an unchangeable inner spread-starting position in a spread end position.

Such a sewing machine is also known from JP 2001 334082 A.

With the displacement of the Nähgutklammern a pulling apart, a so-called spreading, of the previously firmly clamped in the Nähgutklammern sewing material is achieved so that the fabric is thus spent in a taut, flat state. As a result, high-quality buttonholes can be produced. With the spreading of the fabric is also achieved that there is sufficient space for the needle when the buttonhole is first cut and then sewn, ie when the sewing machine works in the so-called Vorschneide mode. The amount of displacement is up to 1.0 mm on each fabric clamp so that they are spaced by a spreading distance of up to 2.0 mm are relocatable. The amount of spreader travel depends on various sewing parameters such as the nature of the fabric, ie weave density, material and the like, the type of yarns to be sewn, the yarn tension values, the needle thickness, if necessary, the processing of a gimp yarn and other parameters.

A disadvantage of the known sewing machine, that the spreading-starting position and the amount of Spreizweges, so the spreading end position, only by a time-consuming adjustment with the aid of tools, such as screwdrivers and measuring tool, are executable. For the implementation of this work, the use of a trained mechanic is required. The numerous components required for adjustment are susceptible to wear. It is difficult to find the once empirically determined settings again, to make reproducible. Each different width buttonhole seam requires a new setting; otherwise, it is not possible to clamp the fabric near the buttonhole seam to be produced.

From DE-PS 457 750 a spreading device for the workpiece clamp of buttonhole sewing machines is known, which has Nähgutklammern which are symmetrical to a central plane by means of a mechanism displaced. There is provided a lever mechanism having a manually adjustable stop, by the adjustment of the spreading path is variable. This known device has the aforementioned disadvantages.

From DE 29 38 064 C2 (corresponding to US-PS 4,312,283), a sewing machine is known, in which by a CNC control unit coordinate values for a Retativbewegung between a sewing machine and one in its size adjustable material holder can be generated. In order to avoid a collision of the needle with the Nähguthalter the control unit information about the current size setting of the fabric holder supplied, so that the control unit can automatically perform a corresponding correction of a sewing program.

The invention has the object of providing a CNC-controlled buttonhole sewing machine of the generic type so that the adjustment of the spreading path can be adjusted by the operator without the use of tools with very little time according to the current Nähbedingungen.

This object is achieved by the features in the characterizing part of claim 1. As a result of the solution according to the invention, it is achieved that the spread path can be preset in a very comfortable manner by inputting into the control unit, so that the values of the spread path corresponding to the current sewing conditions can be set in a simple manner. These include the quality of the sewing material, the parameters of the buttonhole seam, thread tension values of the threads processed during sewing, etc. This increases the quality of a buttonhole by very exact adjustment of the spread end position after moving the Nähgutklammern from the Spreizauss Position reached by the spreading path in the spreading end position. Spreader-starting position is the distance of the Nähgutklammern understood in their rest position in which they are close to each other. Under the spread-end position, the position of the Nähgutklammern is understood, in which they are moved from the spread-starting position to the spreading path. These setting operations can be performed by the operator, resulting in a high ease of use. The setting can be done without use be carried out by special aids. Machine downtime can be eliminated due to the time required for the adjustment. The company mechanic is relieved. The entered control data forms a basis for further processing of the setting values in an optical display and / or for calling up stored sewing programs. The production of high-quality buttonholes is therefore reproducible.

Through the development according to claim 2 it is achieved that the spreading-starting position of the respective shape and size of a buttonhole seam to be generated can be adjusted. This makes it possible to clamp the fabric near the seam to be produced. This leads to a particularly reliable stitch formation and thus a particularly good buttonhole quality.

The development according to claim 3 leads to a particularly advantageous embodiment, since in this case only one Nähgutklammer relative to the x-y-table must be displaced, with a compensation movement is generated by the already existing displaceability of the x-y-table. This leads to a reduction of the required components and thus a more reliable operation and also to lower production costs.

The embodiment according to claims 4 and 5 also leads to a very simple embodiment.

In the claims 7 to 10, an advantageous embodiment is specified, in which at least transfer of the displaceable Nähgutklammer no forces in the guides of the fabric clamp on the xy-table become. Thus, no friction forces occur during the positioning of the fabric clamp, which counteract the displacement of the fabric clamp for spreading. The forces occurring during the stapling of a sewing material thus remain in the sewing material clamp itself. This in turn has an advantageous effect on the speed and precision of the spreading process. In addition, the entire spreading can be lighter, so constructed to save material.

Fig. 1

eine Seitenansicht einer Knopfloch-Nähmaschine,

Fig. 2

eine Teil-Draufsicht auf einen x-y-Tisch der Nähmaschine entsprechend dem Sichtpfeil II in Fig. 1,

Fig. 3

eine Teil-Ansicht der Nähmaschine in gegenüber Fig. 1 vergrößertem Maßstab und in bereichsweise aufgebrochener Darstellung,

Fig. 4

eine Draufsicht auf den in Fig. 3 gezeigten Teil der Nähmaschine entsprechend der Schnittlinie IV-IV in Fig. 3,

Fig. 5

einen perspektivisch dargestellten Teil der Knopfloch-Nähmaschine einschließlich der schaltungsmäßigen Verknüpfung der verschiedenen Antriebe mit der Steuer-Einheit und der Bedien-Einheit,

Fig. 6

Teile in einer Draufsicht in einem gegenüber Fig. 2 vergrößerten Maßstab,

Fig. 7

eine Draufsicht auf ein Nähgut mit einem Augen-Knopfloch,

Fig. 8

eine schematische Darstellung eines zweiten Ausführungsbeispiels der Erfindung,

Fig. 9

eine Teil-Seitenansicht eines dritten Ausführungsbeispiels der Erfindung,

Fig. 10

einen Horizontal-Schnitt durch das dritte Ausführungsbeispiel entsprechend der Schnittlinie X-X in Fig. 9, und

Fig. 11

einen Querschnitt durch das dritte Ausführungsbeispiel entsprechend der Schnittlinie XI-XI in Fig. 9.

The invention will be explained in more detail with reference to three exemplary embodiments illustrated in the drawing. It shows

Fig. 1

a side view of a buttonhole sewing machine,

Fig. 2

1 is a partial plan view of an xy table of the sewing machine corresponding to the sighting arrow II in FIG. 1,

Fig. 3

2 is a partial view of the sewing machine in relation to FIG. 1 enlarged scale and in a partially broken-away representation,

Fig. 4

3 shows a plan view of the part of the sewing machine shown in FIG. 3, corresponding to the section line IV-IV in FIG. 3,

Fig. 5

a perspective view of part of the buttonhole sewing machine including the circuit-wise connection of the various drives with the control unit and the control unit,

Fig. 6

Parts in a plan view in a comparison with FIG. 2 enlarged scale,

Fig. 7

a plan view of a fabric with an eye buttonhole,

Fig. 8

a schematic representation of a second embodiment of the invention,

Fig. 9

a partial side view of a third embodiment of the invention,

Fig. 10

a horizontal section through the third embodiment according to the section line XX in Fig. 9, and

Fig. 11

a cross section through the third embodiment according to the section line XI-XI in Fig. 9.

As can be seen in Fig. 1, a buttonhole sewing machine is C-shaped, i. it has an upper arm 1, a lower, cabinet-like base plate 2 and a connecting both, approximately vertical stand 3. In the arm 1, an arm shaft 4 is mounted in the usual manner, which is driven by a 4 indicated only in Fig. Drive motor 4a. From the arm shaft 4, the drive of a vertically displaceable needle bar 5 with a needle 6 and a vibratory drive are derived for this purpose in a conventional manner.

On the base plate 2, an xy-table 7 is arranged, which is thus one in two horizontal coordinate directions, namely the x-direction and the y-direction, sliding cross slide is. The xy-table 7 is formed in a conventional manner, as it is known for example from DE 198 07 771 A1 (corresponding to US-PS 6,095,066). The drive of the xy-table 7 takes place by means of only indicated in Fig. 5 drives, namely an x-drive 8 and a y-drive 9, which are positionable electric motors, so preferably preferably stepper motors, or even controllable DC motors is.

On the x-y table 7, a support plate 10 is arranged, which is supported via a ball-linear guide 11 in the x-direction slidably on the x-y table 7. It is displaceable in the x-direction by means of a sliding drive 12 designed as a stepping motor. This drive 12 is - as shown in FIGS. 3 and 4 can be removed - attached to the xy table 7 and acts on a mounted on its shaft 13 eccentric 14 and cooperating with this sliding block sliding connection 14 a on the support plate 10, so maximum displacements of the support plate 10th in the x direction corresponding to the double eccentricity of the eccentric 14 are possible. The displacement paths are in the range of about 2 mm.

Above the support plate 10, a two-part support plate 15a, 15b is arranged. The - seen in the y-direction - left part-support plate 15a is fixed by means of screws 16a on the x-y table 7, so this immovable. In contrast, the - seen in the y-direction - right part support plate 15b is fastened by means of screws 16b on the sliding support plate 10, so with this displaceable in the x direction. The tops of the partial support plates 15a, 15b lie in a common x-y plane.

On each partial support plate 15a or 15b, a fabric clamp 17a or 17b is mounted, each one on the respective part support plate 15a, 15b mounted partial support plate 18a, 18b, which is associated with a respective clamping plate 19a and 19b. The clamping plates 19a, 19b are mounted on bearing levers 20, which are each mounted by means of a pivot bearing 21 on the associated part-support plate 15a and 15b. The Nähgutklammern 17a and 17b are relative to the respective partial support plate 15a, 15b - apart from the pivoting about the pivot bearing 21 - stationary. The Nähgutklammern 17a, 17b are pivotable by means of drive levers 22 which are actuated by a pneumatically actuated clamping drive 22a. The respective partial support plate 18a, 18b and the respective clamping plate 19a and 19b have partial openings 23a, 23b, which complement each other to an opening which surrounds a buttonhole seam 24 to be produced at a small distance.

The partial support plates 15a, 15b can be moved against each other in a vertical mid-plane 25 against each other, in which they and also the Nähgut-Klammem 17a, 17b are in their respective zero position. In this position, the opposing edges 26a, 26b of the sub-support plates 15a, 15b against each other. In this plane 25, a stationary knife 27 for cutting a button hole 28 is also arranged on the base plate 2 of the sewing machine. This knife 27 is part of a cutting device 29, which also includes an anvil 30, which is attached by means of a cutting drive 31 on the underside of the arm 1.

The sewing machine is provided with a control unit 32, via which the x-drive 8, the y-drive 9, the shift drive 12, the drives 22a for the Nähgutklammern 17a, 17b, the drive motor 4a of the arm shaft 4 and the cutting drive 31 are controlled. The control unit 32 has a storage part 33. Furthermore, it is associated with an operating unit 34 with an input keyboard 35 and a display 36.

The memory part 33 stores the programs and data relating to the buttonhole seam 24 to be produced and the spread-out position. Also stored are spreader paths associated with the nature and shape of the buttonhole seam 24 and the quality of the fabric.

Before starting a sewing operation, the xy table 7 is brought into a zero position according to the data stored in the memory part 33 in the usual way by means of the stepping motors 8, 9 in which the edges 26a, 26b of the part support plates 15a, 15b abut each other in the plane 25 and the center plane 25 also receives the needle 6 in its vertical middle position. Such zero position adjustments are common in sewing control technology and therefore need no further explanation. By appropriate operation of the operating unit 34, the operator selects a certain type of buttonhole 28 with buttonhole seam 24. In addition, it calls a corresponding control program to which the substance data and the like are assigned.

By entering the start of sewing, the already mentioned zero position adjustment is carried out automatically on the one hand. In addition, by appropriate control of the sliding drive 12, the support plate 10 with the part support plate 15b and the Nähgutklammer 17b spent in a spread-starting position in which the partial openings 23a, 23b limiting longitudinal edges 37a, 37b of the clamping plates 19a , 19b have a distance a from one another which corresponds to the total width b of the buttonhole seam 24 plus a distance c of, for example, 0.5 mm between each buttonhole seam 24 and each adjacent longitudinal edge 37a or 37b. If the clamping plates 19a, 19b with their partial openings 23a, 23b of the buttonhole seam 24 to be produced are already exactly matched, then it is necessary There is no adjustment of the previously described type, but only the zero-position setting of the xy-table. 7

The sewing material clamps 17a, 17b are now opened by the operator via the operating unit 34 or automatically according to the stored sewing program, and the operator can place and align the sewing material 38 on the support plates 18a, 186. Subsequently, the sewing material clamps 17a, 17b are closed by corresponding actuation of the drive 22a, so that the sewing material 38 is clamped in the two sewing material clamps 17a, 17b. Thereafter, the method of the support plate 10 with the Nähgutklammer 17 b to the stored in the memory part 33 spreading path d in the x-direction takes place fully automatically by means of the controlled by the control unit 32 shift drive 12. Simultaneously or immediately thereafter, the xy-table 7 is moved by a distance d / 2 in the opposite direction, so that the two support plates 18a, 18b are again mirror-symmetrical to the central plane 25 in its spread-end position. As a result, the part-openings 23a, 23b are in turn mirror-symmetrical with respect to the center plane 25. The stapled and now spread material 38 is located under the needle 6 in the position exactly defined for carrying out the sewing operation. In FIG. 6, the clamping plate 19b is pulled out in its initial position and dashed in its spread position by the method of the support plate 10 to the spreading path d but before the compensation by the back-process of the xy-table 7 by half a spread path d / 2 shown. The cutting of the buttonhole 28 by means of the knife 27 can be done before sewing the buttonhole 28 or after sewing. As can be seen in FIG. 7, the buttonhole seam 24 is a conventional bead seam which is produced by a corresponding needle oscillating drive of the needle bar 5. It can in addition to the buttonhole eye 39 opposite end of the buttonhole seam 24 an unillustrated end bar are sewn.

FIG. 8 diagrammatically shows a further embodiment in which two support plates 15'a, 15'b on spherical-linear guides 11 'are displaceably arranged in the x-direction on an x-y table 7'. To shift a spindle 40 with opposite threads 41a, 41b, which engage in spindle nuts 42a, 42b. The spindle nuts 42a, 42b are connected to the support plates 15'a, 15'b. By appropriate control of the arranged on the xy table 7 'shift drive 12', the support plates 15'a, 15'b in the x-direction toward or away from each other, in each case mirror-symmetrically to the center plane 25. On the Support plates 15'a, 15'b are arranged in the same manner as in the first described embodiment, the Nähgutklammern, which are not shown in Fig. 8. In the embodiment according to FIG. 8 likewise a zero position adjustment of the x-y table 7 'takes place; it is done in the same way the spreading of the fabric clamps, not shown, with the fabric; but it requires no compensation of the spread path by an opposite method of the x-y table 7 'by half the spread path d / 2.

In the embodiment according to Figures 9 to 11, two support plates are displaceably arranged on an xy table 7, of which only the support plate 15 "b is indicated The design and mounting correspond to that according to the first embodiment This embodiment differs from the previous ones described in that at least on the relative to the xy table 7 sliding support plate 15 "b attached fabric clamp 17" b is actuated by a clamping drive 43 which is attached to the support plate 15 "b. This is the double-arm bearing lever 20 ", which carries the clamping plate 19b, mounted by means of a pivot bearing 44 in a drive and bearing housing 45 which is secured to the underside of the support plate 15" b by means of screws 46. Both parts are connected at their contact surface using a liquid sealant, not shown, compressed air tight together.

In the housing 45, a top and bottom open cylinder space 47 is formed, in which a piston 48 is arranged sealed up and down movable. This piston 48 has a piston rod 49 projecting downwards out of the cylinder space 47, which is articulated by means of a joint 50 at the facing end of the bearing lever 20 ".A compressed air channel 51 is formed in the housing 45 next to the cylinder space 47. which is connected at the top of the housing 45 by means of an overflow channel 52 with the cylinder space 47. This unit forms a one-sided acted upon pneumatic piston-cylinder unit .On the underside of the housing 45 opens into the compressed air channel 51, a compressed air Line 53, in which a solenoid valve 43 'is located, which is controlled by the control unit 32.

In the housing 45 next to the compressed air channel 51, a bore 54 is formed in which a prestressed tension spring 55 is arranged, which is fixed by means of a retaining pin 56 at the top of the housing 45 and by means of another retaining pin 57 on the bearing lever 20 ". By means of the prestressed tension spring 55, the lever portion 58a between the pivot axis 44 and the hinge 50 is pulled upwards, so the clamping drive 43, so that the lever portion 58b of the bearing lever 20 "is pivoted upwards, ie the clamping plate 19b of the support plate 15 "b. In contrast, if via the compressed air line 53, the compressed air channel 51 and the overflow channel 52 compressed air in the room 47 flows above the piston 48, then the piston 48 is displaced together with the lever portion 58a against the force of the tension spring 55 so that the lever portion 58b is pivoted with the clamping plate 19b to the support plate 15 "b out, whereby an optionally existing fabric part 38 is held clamped.

In the lever portion 58a a coming against the housing 45 adjusting screw 59 is arranged, by means of which can be adjusted by which way the clamping plate 19b is raised.

The arrangement of the clamping drive 43 between the bearing lever 20 "and the support plate 15" b ensures that the forces acting in the Nähgutklammer 17 "b remain within the bracket, so not on the x-y table 7" act.

The other support plate with clamping plate is designed in the same way. This embodiment of the Nähgutklammern can be implemented not only in the embodiment of FIGS. 1 to 7, but also in the in Fig. 8.

Claims (10)

1. A CNC-controlled buttonhole sewing machine, comprising

   - a needle (6), which is drivable via an arm shaft (4);

   - an x-y table (7, 7'),

   -- which is movable by an x drive (8) in an x direction and by a y drive (9) in a y direction, and

   -- which supports a first and a second work piece clamp (17a, 17b, 17"b), the first and second work piece clamps (17a, 17b, 17"b) being mounted for displacement relative to each other, and

   -- which comprises a sliding drive (12, 12') for displacement of the work piece clamps (17a, 17b, 17"b) from an initial position of spread by a length of spread (d) into a final position of spread; and

   - a control unit (32) for control of the drives (8, 9, 12, 12') for displacement of the x-y table (7, 7') prior to the start of production of a buttonhole seam (24),

   characterized
   in that the sliding drive (12) at least of the first work piece clamp (17b, 17"b) is an electric positioning motor; and
   in that the control unit (32) includes a data storage (33) with data stored therein for displacement of the at least one first work piece clamp (17b, 17"b) by a given length of spread (d).
2. A buttonhole sewing machine according to claim 1, characterized in that data are stored in the data storage (33), for displacement at least of the first work piece clamp (17b, 17"b) in relation to the second work piece clamp (17a) into an initial position of spread.
3. A buttonhole sewing machine according to claim 1 or 2, characterized
   in that only the first work piece clamp (17b, 17"b) is displaceable in relation to the x-y table (7) and that the second work piece clamp (17a) is stationary in relation to the x-y table (7); and
   in that data are stored in the control unit (32) for displacement of the first work piece clamp (17b, 17"b) by a given length of spread (d) and for displacement of the x-y table (7) in a reversed direction by half the given length of spread (d).
4. A buttonhole sewing machine according to claim 1 or 2, characterized in that the first and the second work piece clamp (17a, 17b, 17"b) are displaceable one in relation to the other in an opposite direction.
5. A buttonhole sewing machine according to claim 4, characterized in that the first and second work piece clamps (17a, 17b, 17"b) are displaceable by only a single sliding drive (12').
6. A buttonhole sewing machine according to one of claims 1 to 5, characterized in that the electric positioning motor is a stepper motor.
7. A buttonhole sewing machine according to one of claims 1 to 6, characterized in that at least the first work piece clamp (17"b) comprises a supporting plate (15"b) for accommodation of a work piece (38) and a clamping plate (19b) mounted on the supporting plate (15"b); and
   in that a clamping drive (43) for actuation of the clamping plate (19b) supports itself on the supporting plate (15"b).
8. A buttonhole sewing machine according to claim 7, characterized in that the clamping drive (43) is a pneumatic piston-cylinder drive.
9. A buttonhole sewing machine according to claim 8, characterized in that the clamping drive (43) comprises a drive casing (45) mounted on the supporting plate (15"b) and having a cylindrical chamber (47) in which a piston (48) is arranged for displacement, the piston (48) being connected to a bearing lever (20") which carries the clamping plate (19b).
10. A buttonhole sewing machine according to claim 8, characterized in that the clamping drive (43) is a unilaterally actuated piston-cylinder drive.

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