Process for embroidering three-dimensional workpieces

Abstract

The present invention relates to a method for embroidering three-dimensional workpieces (2) using an embroidery machine (100) comprising at least one embroidery head (101) and at least one embroidery frame (1) for positioning the workpiece (2). The method according to the invention is characterized in that the workpiece (2) is positioned by means of the embroidery frame (1) at at least two angles (Θ, µ, ω) ​​with respect to at least two axes (X, Y, Z) which are related to the axis of movement of the embroidery head (101), in order to introduce at least one stitch of an embroidery into the workpiece (2).

Description

Technical area

[0001] The present invention relates to a method for embroidering three-dimensional workpieces according to the preamble of patent claim 1. State of the art

[0002] It is known from the prior art that embroidery machines can embroider not only flat structures, but also curved structures. A corresponding patent can be found in DE 44 37 021 C2. Such curved structures are often half-shells and are used as headgear in the form of caps. Various patents can be found for this purpose, such as DE 44 37 021 C2, US 5 884 572 A, and WO 2004 / 031467 A1. Common to these patents is the fact that the embroidery frames, arrangements, and methods described therein relate to the embroidering of a section of the outer surface of a cylinder. Furthermore, sewing robots are known that can process curved surfaces.

[0003] Furthermore, sewing robots are known that can process curved surfaces, as shown, for example, in the patent US 2022 / 290346 A1.

[0004] Post-bed sewing machines are used to sew hollow bodies and are also assumed to be known. One embodiment is described in WO 2012 / 150536 A2, which also describes various embodiments of the hook assembly. Also worth mentioning is patent JP 2022 015729 A, which essentially describes changing a bobbin on a post-bed sewing machine using a robot.Document JP 2022 015729 A discloses a method for embroidering three-dimensional workpieces (skins for automotive trim) using an embroidery machine comprising at least one embroidery head for embroidery and at least one embroidery frame for positioning the workpiece. The workpiece is positioned by means of the embroidery frame through at least two angles (six rotations about six axes, indicated by six double-headed arrows) with respect to at least two axes (six axes) relative to the axis of movement of the embroidery head, in order to insert at least one stitch of an embroidery into the workpiece. The descriptive text of patent JP 2022 015729 A also states that the robot used for changing the bobbin thread can move a three-dimensional workpiece for embroidery around several axes beneath an embroidery head by means of a suitable embroidery frame attached to its handpiece.

[0005] The full-surface embroidery of a curved, three-dimensional structure using inexpensive movement equipment is not possible today with an embroidery machine. Instead, in the case of a cap, for example, only a partial area is embroidered, which almost corresponds to a rectangular section of a cylinder's surface. The movement for embroidering such a section of a cylinder's surface in relation to the needle is derived from the X and Y directions of a partially existing embroidery frame. This is done in such a way that the movement in the depth direction Y of the pantograph of the embroidery machine is maintained. In contrast, the lateral movement X of the pantograph is converted into a rotary movement, for example by means of a cable pull. This makes it possible to embroider part of a cap, whereby this part is determined by the way the cap is clamped before the embroidery process.The motif to be embroidered on this section is specified to the embroidery machine's control system in the form of stitch data. This stitch data is a sequence of data in the form of a triplet consisting of an adjustment path in the X direction, an adjustment path in the Y direction, and the information to create a stitch at the position reached on the cap to be embroidered after the adjustment. A large number of these triplets in an ordered sequence one after the other creates the desired motif on the cap. Since the section to be embroidered is part of a cylinder surface, its unfolding can be viewed as a flat, rectangular element. Therefore, to create the stitch data triplet, a motif is simply artistically designed on a rectangular base area, since the use of the aforementioned cable pull mechanism inherently transfers the data to the section of the cylinder surface.

[0006] If several parts of such a cap are to be embroidered, this is only possible by laboriously re-clamping the cap so that several cylindrical sections can be embroidered one after the other. Description of the invention

[0007] The present invention is based on the object of eliminating the aforementioned disadvantages and eliminating the limitation of embroidering a workpiece to a rectangular section of a cylinder surface. To this end, the present invention demonstrates how almost full-surface embroidering of the surface of a workpiece can be advantageously achieved. In the following description, the term "workpiece" is used, since the invention presented here is not limited to the embroidery of caps.

[0008] According to the invention, the above object is achieved according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous embodiments and further developments of the inventive method are specified in the dependent subclaims 5 and 6. An embroidery machine according to the invention is defined in claim 2. Preferred embodiments of the embroidery machine are defined in subclaims 3 and 4.

[0009] The method according to the invention for embroidering curved three-dimensional workpieces is carried out using an embroidery machine which comprises at least one embroidery head for embroidering and at least one embroidery frame for positioning the workpiece, wherein the workpiece is positioned rotatably through at least two angles about correspondingly at least two axes X, Y, Z, which are related to the axis of movement of the embroidery head, for introducing at least one stitch of an embroidery into the workpiece.

[0010] The present invention enables the embroidery of a workpiece (e.g., a cap) in a single setup over virtually the entire surface of the workpiece. According to the invention, this is achieved by the method according to the invention and an embroidery frame, including drives, described in more detail below, using a particular embodiment of the embroidery machine, applying the method according to the invention for positioning the workpiece, as defined in claim 1 and the subsequent subclaims according to the features listed. Brief description of the drawings

[0011] Further objects, features, advantages and possible applications of the method according to the invention, an embroidery frame and an embroidery machine will become apparent from the following description of embodiments with reference to the drawings.

[0012] The drawings show Fig. 1 a post-bed embroidery machine with an embroidery frame for full-surface embroidery; Fig. 2 an embroidery frame for full-surface embroidery with the axes and rotation angles; Fig. 3 an embroidery frame for full-surface embroidery with its individual elements; Fig. 4 an embroidery frame for full-surface embroidery with a stretched workpiece, here a cap; Fig. 5 an embroidery frame for full-surface embroidery with a cap stretched out and an exemplary embroidery position set according to the angle of rotation Θ = +45° µ = 0 ω = 0; Fig. 6 an embroidery frame for full-surface embroidery with a cap stretched out and an exemplary embroidery position set according to the rotation angle Θ = 0° µ = -45° ω = 0°; Fig. 7 an embroidery frame for full-surface embroidery with a cap stretched out and an exemplary embroidery position set according to the rotation angle Θ = +30° µ = +30° ω = 180°. Implementation of the invention

[0013] As from Fig. 1 As can be seen, the embroidery frame 1 according to the invention for positioning a workpiece 2 for carrying out the method according to the invention comprises at least one drive 3, 4, 5 for the driven positioning of the workpiece 2 by the at least two angles Θ, µ, ω.

[0014] Furthermore, the present invention relates to an embroidery machine 100 for carrying out the method according to the invention, which comprises at least one embroidery head 101 for embroidering and at least one embroidery frame 1 according to the invention for positioning the workpiece 2.

[0015] In a particularly advantageous embodiment of the invention, such an embroidery machine 100 can also comprise a plurality of embroidery frames 1, wherein each of these plurality of embroidery frames 1 is assigned at least one embroidery head 101.

[0016] According to the invention, the embroidery machine 100 is provided with a movement device for the curved three-dimensional workpiece 2, which allows the tilting of the curved workpiece 2 by the two independent but limited angles Θ and μ, as well as the rotation by the infinite angle of rotation ω. This arrangement makes it possible to bring almost any position of the surface of the curved workpiece 2 below the needle position.

[0017] Fig. 1 shows a (post-bed) embroidery machine 100 with a control system. The (post-bed) embroidery machine 100 is equipped with an embroidery head 101 that is equipped with multiple needles, whereby only one of the multiple needles within the embroidery head 101 is connected to the drive mechanism of the embroidery head at any one time. By laterally displacing the embroidery head 101, it is possible to select a different one of the multiple needles, so that this needle is driven by the drive mechanism of the embroidery head 101. Since the different needles can be equipped with differently colored threads, for example, this makes it possible to create embroidered areas of different colors in order to achieve the artistic impression of the embroidery.

[0018] Fig. 1 further shows the embroidery frame 1 according to the invention for full-surface embroidery as well as several drives 3, 4, 5 of the embroidery frame 1.

[0019] In Fig. 2 The embroidery frame 1 for full-surface embroidery and the drives 3, 4, 5 of the embroidery frame 1 are shown in detail in relation to the embroidery head 101. The Cartesian axes X, Y and Z are shown for orientation. According to the invention, but without limiting its general validity, the angle Θ denotes a rotation about the X-axis, the angle µ a rotation about the Y-axis and the angle ω a rotation about the Z-axis. The angles Θ and µ can assume both positive and negative values, but are limited due to the mechanical arrangement. The angle ω can also assume positive and negative values ​​and is not limited by the mechanical arrangement, as will be explained further.

[0020] Fig. 3 shows the embroidery frame 1 according to the invention for full-surface embroidery in relation to at least one advantageously provided (hook) column 102. The (hook) column 102 accommodates the hook, which accommodates the usual bobbin thread. The embroidery frame 1 is suspended in a cardanic manner within the (hook) column 102. This cardanic suspension allows the Fig. 2 The illustrated rotations by the angle Θ around the X-axis and by the angle μ around the Y-axis are as previously described. To perform the rotation around the X-axis, drive 3 is used to adjust the angle Θ. Performing a positive adjustment of drive 3 results in the front area of ​​embroidery frame 1 pivoting upwards by the positive angle Θ and the rear area of ​​embroidery frame 1 pivoting downwards to the same extent. Accordingly, the pivoting directions are reversed when drive 3 is adjusted negatively.

[0021] Independently, drive 4 serves to adjust the angle µ around the Y-axis. Performing a positive adjustment of drive 4 causes the right section of embroidery frame 1 to pivot upwards by the positive angle µ, and the left section of embroidery frame 1 to pivot downwards by the same amount. Accordingly, the pivot directions are reversed when drive 4 is adjusted negatively.

[0022] Since the two drives 3, 4 are orthogonal to each other for the angles Θ and μ, it is possible to bring the entire surface of the clamped workpiece 2 under the needle positions for embroidery. The orthogonal arrangement of the drives 3, 4 to each other is one of several possible embodiments.

[0023] Fig. 3 shows further elements of the embroidery frame 1 according to the invention for full-surface embroidery. A strut 8 connects the fixed inner ring 7 along the X-axis to the cardanic suspension within the (hook) column 102. Accordingly, the strut 9 connects the fixed inner ring 7 along the Y-axis to the cardanic suspension within the (hook) column 102.

[0024] A rotatable outer holder 6 serves to hold the workpiece 2 - as in Fig. 4 shown - to be picked up during embroidery and held at the lower edge. The rotatable outer holder 6 is mounted on the fixed inner ring 7 in such a way that a rotation of the outer holder 6 around the inner fixed ring 7 by the angle ω is possible. This can be achieved, for example, by a circumferential groove being machined on the inside of the outer holder 6 and webs being attached to the outside of the fixed ring 7, which webs engage in the circumferential groove of the holder 6. The drive 5 is used to realize the rotation of the outer holder 6 by the angle ω around the Z-axis. The transmission of the drive energy of the drive 5 to the outer holder 6 can be achieved, for example, by a gear ring being machined all the way around the inside of the outer holder 6 and a driven gear from the drive 5 engaging with this gear ring and thus transmitting the rotary movement.According to the invention, this arrangement allows continuous, unlimited rotation of the workpiece 2 around the Z-axis. The angle of rotation ω can assume any positive or negative value.

[0025] By implementing the three independent angle adjustments Θ, µ and ω, the embroidery of the workpiece according to the invention is advantageously possible in one clamping and over almost the entire surface of the workpiece 2 as well as circumferentially.

[0026] The Figuren 5 , 6 und 7 Each shows different positions of the workpiece 2 in relation to the needle position. Thus, almost full-surface embroidery of a three-dimensional workpiece 2 is possible using the movement system described here.

[0027] Particularly advantageously, according to the method, the respective new position of the workpiece 2 is determined from predetermined coordinate triplets and the at least one embroidery frame 1 is controlled by means of the drives 3, 4, 5 in such a way that the positioning of the workpiece 2 is carried out by the angles Θ, µ, ω.

[0028] Furthermore, it may be advantageous that the positioning of the workpiece 2 by the angles Θ, µ, ω is calculated and carried out step by step from continuously transmitted coordinates for each stitch of the embroidery.

[0029] The control of the musculoskeletal system is preferably carried out by the drives (drive units) 3, 4 and 5. These can be powered by an electric motor or by any other drive energy source.

[0030] To control the correct movement of the drives 3, 4, 5, a control system is preferably provided that determines the respective new position of the workpiece 2 from predetermined coordinate triplets and adjusts it using the drives 3, 4, 5. By synchronizing the positioning of the workpiece 2 with the drive mechanism of the embroidery head 101, it is achieved that the needle only penetrates the workpiece 2 after it has been positioned, thus performing an embroidery stitch. By continuously adjusting the workpiece 2 and inserting the additional stitches based on the evaluation of the successive coordinate triplets, the entire surface of the workpiece 2 is embroidered. List of reference numbers

[0031] 1Embroidery frame for full-surface embroidery with drives 2Workpiece (cap) 3Drive for angle adjustment Θ 4Drive for angle adjustment µ 5Drive for angle adjustment ω 6Rotatable outer ring for holding the workpiece 7Fixed inner ring 8Bracing X-direction 9Bracing Y-direction 100Post-bed embroidery machine with control 101Embroidery head 102(Hooker) column for holding the hook

Claims

1. Method for embroidering curved three-dimensional workpieces (2) using an embroidery machine (100) which comprises at least one embroidery head (101) for embroidering and at least one embroidery frame (1) for positioning the workpiece (2), wherein the workpiece (2) is positioned by means of the embroidery frame (1) about at least two angles (Θ, µ, ω) about corresponding to at least two axes (X, Y, Z) which are in relation to the axis of movement of the embroidery head (101), for introducing at least one stitch of an embroidery into the workpiece (2), characterised in that the embroidery machine (100) is provided with a movement apparatus for the curved three-dimensional workpiece (2), which permits tilting of the curved workpiece (2) about two independent but limited angles (Θ, µ) and rotation about an infinite angle of rotation (ω) about correspondingly three Cartesian axes (X, Y, Z).

2. Embroidery machine (100) for carrying out a method according to claim 1, which comprises at least one embroidery head (101) and a hook, which is accommodated in a hook column (102) and accommodates a bobbin thread bobbin, for embroidering and at least one embroidery frame (1) for positioning the workpiece (2), characterised in that the embroidery frame (1) comprises a cardanic suspension within the hook column (102) and at least one drive (3, 4) for the driven positioning of the workpiece (2) about the two limited angles (Θ, µ).

3. The embroidery machine (100) according to claim 2, wherein the embroidery frame (1) comprises an inner fixed ring (7) connected to the cardanic suspension within the gripper column (102) by a strut (8) along the X-axis and correspondingly by a strut (9) along the Y-axis; a rotatable outer holder (6) serves to receive the workpiece (2) during embroidery and to hold it at the lower edge; the rotatable outer holder (6) is mounted on the inner stationary ring (7) in such a way that rotation of the outer holder (6) about the inner stationary ring (7) about the infinite rotation angle (ω) is possible; and a further drive (5) is used to realise the rotation of the outer holder (6) about the Z-axis.

4. Embroidery machine (100) according to one of claims 2 and 3, which comprises several embroidery frames (1) and at least one embroidery head (101) is assigned to each of these several embroidery frames (1).

5. Method for embroidering curved three-dimensional workpieces (2) according to claim 1 while controlling an embroidery machine (100) according to one of claims 2 to 4, wherein determines the respective new position of the workpiece (2) from predetermined coordinate triples and the at least one embroidery frame (1) is controlled by means of the drives (3, 4, 5) in such a way that the positioning of the workpiece (2) is carried out by the angles (Θ, µ, ω).

6. Method according to claim 5, wherein the positioning of the workpiece (2) about the angles (Θ, µ, ω) is calculated and carried out step-by-step from continuously transferred coordinates for each stitch of the embroidery.

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