Sewing machine for forming a peripheral edge seam

Abstract

The invention relates to a sewing machine (1) and to a method for forming a peripheral edge seam in a large-area and preferably multi-layer sewing material (2), such as a mattress panel, the sewing machine comprising: a sewing material support (3); a sewing unit (4), which comprises a needle (8), a hook and a presser foot (9); a transport device for transporting the sewing material (2) relative to the sewing unit (4); and a holding element (12) which can be moved relative to the sewing material support (3) and can be placed onto the sewing material (2), wherein the sewing material (2) can be moved in the sewing direction by means of a conveying device and preferably can be rotated about the surface normal of the sewing material support (3) with the needle (8) inserted, and wherein the holding element (12) has a support element (13), which can be rotated by an angle of rotation from a starting position into an end position relative to the sewing material support (3) and which has a receptacle (15) preferably in the form of a substantially V-shaped notch, in which receptacle the needle (8) and / or the presser foot (9) is located in the case of the end position.

Description

[0001] Sewing machine for forming a circumferential edge seam

[0002] The subject matter of the invention is a sewing machine for forming a circumferential edge seam in a large-area and preferably multi-layered sewing material, such as a mattress board, with a sewing material support, a sewing unit having a needle, a hook and a presser foot, a transport device for the sewing material relative to the sewing unit, and a holding element which is movable relative to the sewing material support and can be placed on the sewing material, wherein the sewing material can be moved in the sewing direction by means of a conveying device and can be rotated about the surface normal of the sewing material support, in particular when the needle is inserted. The invention further relates to a method for forming a circumferential edge seam and / or for arranging a hem in oron a large-area and preferably multi-layered sewing material, such as a mattress plate or a quilt, which rests on a sewing material support and is fed to a sewing unit having a needle, a looper and a presser foot, wherein the sewing material is moved relative to the sewing unit with a transport device and rotated with a holding element which is movable relative to the sewing material support and can be placed on the sewing material, wherein the sewing material is preferably rotated about the surface normal of the sewing material support when the needle is inserted.

[0003] When processing large-area, preferably multi-layered, fabrics, it is desirable to form the edges of the fabrics with an edge seam. This is even more desirable the more layers the fabric has, as is the case with mattress panels, for example. Such fabrics are processed on sewing machines and should be as automated as possible so that the edge seams can be formed continuously in a fabric. Various sewing machines are known for this purpose.

[0004] For example, US 6,082,277 discloses a generic sewing machine for forming a circumferential edge seam in a large-area sewing material consisting of multiple layers. In this previously known sewing machine, the sewing material rests on a sewing material support and is transported past a sewing unit. The sewing unit has a needle, a hook arranged below the sewing material support, a presser foot, and a transport device with which the sewing material is transported past the sewing unit at a predetermined speed so that the needle and hook execute successive sewing stitches that ultimately form the edge seam. If the sewing material reaches an end region with an edge to be sewn, it is necessary to rotate the sewing material by 90° in a subsequent step so that the edge seam can then be formed in the next edge.In the prior art, a combination of at least two rollers is provided for rotating the sewing material by 90°, of which one roller acts on the underside of the sewing material in the area of ​​the sewing unit, while a second, centrally arranged roller executes a movement in the opposite direction to the first roller, so that an overall rotation of the sewing material results.

[0005] As with many such sewing machines, this state-of-the-art technology also has the disadvantage that the forces acting on the fabric at two distant positions can lead to folding of the fabric in or next to the force applied. A further disadvantage is that the individual layers of the fabric are shifted relative to one another if the fabric is twisted. A subsequent sewing process in the sewing unit can therefore result in poorly executed edge seams being formed, which means that the fabric does not meet the required quality and is no longer suitable for further processing and sale. There is therefore a risk of producing high levels of waste, which increases production costs.

[0006] In the prior art according to the above-mentioned US document, a rotation plate is additionally provided which is lowered onto the sewing material by means of a cylinder before the sewing material is rotated, so that the sewing material is fixed in the area of ​​the rotation plate in the sense of a pivot point around which the sewing material is rotated in order to form a suitable corner area.

[0007] Based on this prior art, the invention is based on the object of developing a sewing machine in such a way that continuous sewing of edge seams on all four outer edges of a sewing material can be carried out continuously without the risk of folding the sewing material and / or shifting of sewing material layers of the uneven edge seam formation with corresponding crease formation in the sewing material.

[0008] The solution to this problem in a sewing machine according to the invention provides that the holding element has a support element which can be rotated by an angle of rotation from a starting position into an end position relative to the sewing material support and has a receptacle, preferably designed as a substantially V-shaped incision, in which the needle and / or the presser foot is or are located in the end position.

[0009] In a method according to the invention, the object is achieved by rotating the material to be sewn with a support element of the holding element in a position placed on the material by an angle of rotation from a starting position into an end position relative to the material support, wherein a receptacle of the support element, preferably designed as a substantially V-shaped incision, is moved in such a way that the needle and / or the presser foot is / are in the end position in the receptacle.

[0010] In the design of the sewing machine according to the invention, a receptacle is provided in the area of ​​the support element, which is placed on the sewing material support before the sewing material is rotated relative to the sewing material support. This receptacle can be V-shaped and serves to ensure that the needle and / or presser foot is / are in the receptacle in the end position, i.e. in the position reached after the sewing material has been rotated by 90° relative to the sewing material support, so that the support element rests on the sewing material as close as possible to the presser foot and / or needle at the time a new edge seam is started, so that the formation of folds in the area of ​​the support element or presser foot is essentially prevented.The transport device for the sewing material relative to the sewing unit also supports this purpose. In combination with the support element, this transport device moves the sewing material into an unfolded length alignment before the first stitch formation of an edge seam, so that an edge seam is subsequently carried out in an unfolded and also unstretched sewing material.

[0011] Preferably, the starting position and the end position are arranged on a circular arc corresponding to a 90° rotational movement of the support element. The starting position is the position of the holding element upon completion of an edge seam along a first longitudinal edge of the material, while the end position is the starting point of the sewing process with the sewing unit along a next longitudinal edge of the material, which runs perpendicular to the first longitudinal edge of the material. Thus, when the edge seam is completely formed, the material is moved three times by 90° along all four longitudinal edges of the material from a starting position to a final position before the next sewing process is started.

[0012] According to a further feature of the invention, the holding element has two cantilever arms, preferably arranged at right angles to one another, which can preferably be placed on the fabric together with the holding element and can be moved relative to the fabric support. The cantilever arms are aligned substantially parallel to two longitudinal edges of the fabric arranged at right angles to one another and can be placed on the fabric so that, when the fabric moves, it is moved on the fabric support with as few creases as possible, as the cantilever arms guide and support the movement of the fabric on the fabric support.

[0013] Preferably, the holding element is movable parallel to the surface normal of the material support and / or at an angle perpendicular to the surface normal of the material support. Accordingly, lowering of the holding element in the direction of the material on the material support is possible, as is pivoting of the holding element on a circular arc with the material support as the tangential area. In this regard, it has proven advantageous to provide a combination of lowering or raising the holding element with pivoting of the holding element in order to cause the shortest possible downtime of the material transport during the movement of the holding element. With this configuration, only a slight lifting and thus release and subsequent pivoting of the holding element is necessary.

[0014] According to a further development of the sewing machine according to the invention, a tensioning element that is displaceable in the longitudinal axis direction of the cantilever arm, in particular relative to the cantilever arm, is arranged on at least one cantilever arm. The cantilever arm is preferably designed with the tensioning element, which, when the sewing material is rotated, is moved from a starting position substantially perpendicular to the sewing direction to an end position substantially parallel to the sewing direction. The tensioning element tensions a longitudinal edge of the sewing material to be fed with the sewing material so that no wrinkles remain in this area of ​​the sewing material before the sewing process. Corresponding wrinkles could arise due to the rotation of the sewing material. The tensioning element tensions the sewing material in this area and holds the sewing material in a taut and therefore wrinkle-free arrangement. The tensioning element is moved before the cantilever arm rotates to tension the sewing material.The tensioning element is guided, for example, in a groove in the cantilever arm and is preferably continuously movable between two end positions via a linear motor. This allows the tensioning element to be extended depending on the length of the longitudinal edges of the fabric. Excessive tension in the fabric can thus be avoided, so that puckering of the fabric is prevented when the tension is released. The tensioning element is driven by a linear motor, which preferably has a pneumatically movable piston. However, other drives are also conceivable, such as a rack arranged on the tensioning element or on the cantilever arm, which meshes with an electric motor-driven gear.

[0015] According to a further feature of the invention, the conveyor device comprises two conveyor belts, at least one of which is reversible in its conveying direction for rotating the material on the material support. During the normal sewing process, namely when forming an edge seam along a longitudinal edge of the material, both conveyor belts are moved in the same direction at the same speed. Once the end of the longitudinal edge is reached, the material must now be rotated on the material support in such a way that the edge seam can be performed on the subsequent longitudinal edge, which runs at right angles to the first longitudinal edge.To ensure that the fabric is rotated without creases, the conveyor direction is reversed when the end point of the edge seam is reached along the first longitudinal edge of the fabric. This reversed conveyor belt is now driven in a direction opposite to the direction of the second conveyor belt, thus supporting the rotation of the fabric on the fabric support. The conveyor belt can interact, in particular, with the two cantilever arms of the holding element, with the conveyor speed of the reversed conveyor belt being coordinated with the pivoting movement of the two cantilever arms in such a way that the formation of creases in the fabric due to different specific speeds of surface sections of the fabric is prevented.

[0016] Preferably, the rotation of the sewing material is achieved by combining the conveying direction of the conveyor belt and the holding element, in particular the cantilever arm. In a first step, the sewing material is rotated predominantly by the holding element. Once the sewing material reaches a predetermined end position, the rotation is completed with the conveyor belt, aligning the longitudinal edge of the sewing material to be subsequently sewn and / or trimmed parallel to the sewing direction. Preferably, the rotation of the sewing material over at least 80% of the rotation angle takes place via the holding element.

[0017] According to a further feature of the invention, the receptacle for the holding element has a linear boundary which, in the end position, is aligned substantially parallel to a front edge of the presser foot. In this embodiment, the recess is preferably L-shaped, so that a first edge runs along the presser foot and a second edge runs at right angles thereto as a linear boundary parallel to the front edge of the presser foot. This embodiment allows the holding element to be moved very close to the presser foot before the sewing process is carried out after reaching the end position to form a further edge seam along a longitudinal edge of the sewing material.

[0018] Preferably, in this embodiment, it is provided that the straight boundary of the receptacle of the holding element merges into a region of the outer contour of the holding element which is oriented at right angles to the boundary and which, in the end position, is oriented substantially parallel to the edge seam, wherein this region of the outer contour of the holding element is brought as close as possible to the presser foot.

[0019] It is further provided that a hem feed device is assigned to the sewing unit, which feeds a textile strip to the sewing unit as a surrounding element, which element is sewn to the sewing material. This element encompasses the edge of the sewing material and is attached to the sewing material with the edge seam. The element, also referred to as the hem, prevents the individual layers of the sewing material from unraveling, in particular from fraying. The hem also achieves a clean finish, covering, for example, uneven cuts in the individual layers of the sewing material.In the hem feed device, the textile strip is folded in half immediately before reaching the sewing material layer, so that two equal halves of the strip are created, one half of which comes to rest in the area of ​​a lower surface of the sewing material layer and the other half in the area of ​​an upper surface of the sewing material layer, before both halves are sewn together and to the sewing material layer via the edge seam.

[0020] According to a further feature of the invention, the cantilever arms are guided on a frame arranged above the fabric support, in particular via a roller. The cantilever arms can be supported by the frame, so that they rest on the fabric layer with a uniform pressure along their length. For example, increased pressure on the fabric layer at the end of the cantilever arms is prevented.

[0021] According to a further feature of the invention, a third cantilever arm is arranged between the cantilever arms arranged at right angles to one another, positioned at the angle bisector. This third cantilever arm supports the uniform rotation of the fabric on the fabric support and additionally prevents the formation of wrinkles or displacement of the fabric layers relative to one another on the fabric support during rotation of the fabric.

[0022] In a preferred embodiment of the sewing machine according to the invention, at least one sensor is arranged in the area of ​​the material support, via which sensor the alignment of an edge of the material to be sewn and / or trimmed with the sewing unit can be determined parallel to the conveying direction of the material to the sewing unit. This sensor detects the alignment of the material relative to the sewing direction required for a correct sewing process and transmits the data to a control system, which activates the sewing process based on the detected position of the material. The sewing process therefore only starts when the material has reached the intended position for flawless edge seam formation. This can reduce or eliminate the production of defective materials.

[0023] It should be noted that the invention fundamentally allows two different sewing processes. Firstly, it can involve the formation of seams in the area of ​​the longitudinal edges of the sewing material made up of several layers of material, whereby the seams connect the layers of material to one another. Secondly, it can be a trimming process in which the longitudinal edges of the sewing material are formed with a hem that encompasses the longitudinal edges. This hem encompasses and closes the edges of the layers of the sewing material. This ensures a visually appealing design of the sewing material. At the same time, the hem protects the longitudinal edge from opening, for example due to mechanical stress, as occurs during washing processes in washing machines. During the trimming process, trimming of the longitudinal edge to be sewn can be provided.Where this description refers to sewing the long edge or trimming the long edge, both processes should be covered jointly or alternatively.

[0024] Sewing materials, such as quilts, can have two long edges of different lengths, so that two sensors arranged at a distance from one another are provided in the area of ​​the sewing material support. These sensors can determine the parallel alignment of the long edges of the sewing material of different lengths to be sewn and / or trimmed with the sewing unit. The two sensors can be used to process long edges of different lengths in their alignment to the sewing unit. The distance between the sensors can be adjusted. Preferably, one sensor is fixed and one sensor is adjustable relative to it in the area of ​​the sewing material support. The adjustability of the sensors relative to one another allows the sewing machine to be set up quickly and easily for sewing materials of different dimensions.

[0025] Furthermore, a control system can be used to coordinate the sewing process in a transition area between two longitudinal edges of the fabric to be subsequently sewn with the rotation speed of the support element to ensure crease-free sewing in the transition area. For example, the sewing speed and / or stitch length are synchronized with the rotation speed of the support element. For this purpose, the control system has sensors that can detect a starting area and / or an end area of ​​the longitudinal edge to be sewn.

[0026] When trimming the long edges of a fabric, it is necessary to cover the starting area of ​​the first sewn or trimmed long edge with the hem at the end of the sewing or hemming process. A visually and technically appealing finish is made possible by a device that can be moved parallel to the fabric support in the direction of a long edge of the fabric that is in the sewing process. This device shifts a long edge area of ​​the fabric, which is acted upon by the device, towards the support element before a textile strip is sewn and / or trimmed to the long edge area of ​​the fabric. The device allows the area of ​​the long edge that is double-hemmed to be moved slightly away from the sewing unit in order to be able to place an end area of ​​the hem on a starting area and a hem that was sewn to the fabric at the beginning of the sewing process without creating any creases, whereupon the sewing unit carries out the sewing process on this end area.In addition, a strip of the fabric that was previously cut circumferentially from the material can now be completely severed from the material. During this cutting process, the longitudinal edge of the fabric is deflected from its parallel alignment to the sewing direction and thus to the cutting direction of the cutting device, so that the cutting device completely severes the strip of fabric at an angle to its longitudinal axis.

[0027] In the method according to the invention, it is provided that the sewing material is rotated by a support element of the holding element in the position placed on the sewing material by an angle of rotation from a starting position into an end position relative to the sewing material support, wherein a receptacle of the support element, preferably designed as a substantially V-shaped incision, is moved in such a way that the needle and / or the presser foot is / are located in the end position in the receptacle.

[0028] The method according to the invention is preferably further developed in that two cantilever arms of the holding element, preferably arranged at right angles to one another, are placed on the sewing material and are moved with the sewing material relative to the sewing material support.

[0029] In order to enable crease-free sewing and / or trimming of the material to be sewn, a further development of the method provides that the material to be sewn is tensioned in the area of ​​the longitudinal edge of the material to be sewn with a tensioning element that can be moved in the longitudinal axis direction of the cantilever arm, in particular relative to the cantilever arm.

[0030] A very precise alignment of the longitudinal edge to be sewn after the sewing material has been rotated by the holding element can be achieved in that the rotation of the sewing material is carried out at least partially by two conveyor belts of the transport device, of which at least one conveyor belt is driven reversibly in its conveying direction for rotating the sewing material on the sewing material support.

[0031] In order to achieve a clean finish on the long edges of the material to be sewn, the method according to the invention provides that a textile strip is fed to the sewing unit as an encompassing element from a hem feed device, which element is sewn as a hem to the edge area of ​​the material to be sewn. The edge area here comprises the long edges of the material to be sewn. A high level of automation of the method according to the invention can be achieved in that a parallel alignment of the long edges of the material to be sewn and / or trimmed with the sewing unit is detected by a sensor in the area of ​​the material support, wherein preferably two sensors arranged at a distance from one another detect a parallel alignment of the long edges of the material to be sewn and / or trimmed with the sewing unit, of different lengths. The sensors and a control system can be used to sew or trim the material.The trimming process can be started automatically immediately after the intended alignment of the sewing material relative to the sewing unit has been achieved.

[0032] In the method according to the invention, it has further proven advantageous that the sewing material on the sewing material support is rotated in a first step by the holding element and then in a second step by a conveyor belt in the area of ​​the sewing material support.

[0033] It is preferably provided that after completion of an edge seam, the sewing material is rotated by 90° in an edge region of the sewing material with the needle inserted into the sewing material, wherein the rotation is preferably carried out over at least 60°, in particular over at least 80° by means of the holding element and otherwise by means of the conveyor belt and the sewing material is aligned with its edge region parallel to the sewing direction for the execution of an edge seam after completion of the rotation.

[0034] In order to form a straight longitudinal edge in the edge area of ​​the sewing material before attaching a hem, it is provided that in the area of ​​the edge area to be sewn or the longitudinal edge of the sewing material to be trimmed, a narrow strip is cut off to form a straight edge area, before a textile strip is subsequently fed to the sewing material, in particular in the area of ​​the sewing unit, as a comprehensive element from a hem feed device, which element is sewn to the edge area of ​​the sewing material with the sewing unit as a hem.

[0035] The method according to the invention is particularly preferably used for sewing and / or trimming a fabric when seams to be executed in the edge area or the longitudinal edges are formed from lockstitches. Further features and advantages of the invention will become apparent from the following description of the accompanying drawings. The drawings show:

[0036] Fig. 1 a sewing machine in side view;

[0037] Fig. 2 the sewing machine according to Fig. 1 in plan view;

[0038] Fig. 3 is a detailed view of the sewing machine according to Fig. 1 in a first position;

[0039] Fig. 4 is a detailed view of the sewing machine according to Fig. 1 in a second position;

[0040] Fig. 5 is a detailed view of the sewing machine according to Fig. 1 in a third position;

[0041] Fig. 6 the sewing machine according to Fig. 3 in perspective view;

[0042] Fig. 7 shows the sewing machine according to Fig. 5 in a perspective view;

[0043] Fig. 8 is a schematic diagram of a support element of the sewing machine according to Figures 1 to 7 in a first position;

[0044] Fig. 9 shows the support element according to Fig. 8 in a second position rotated by 45°;

[0045] Fig. 10 shows the support element according to Figures 8 and 9 in a third position rotated by 45° relative to the position in Fig. 9 and by 90° relative to the position in Fig. 8;

[0046] Fig. 11 shows a seam feeding device for a sewing machine according to Figures 1 to 10 in a perspective view;

[0047] Fig. 12 shows the seam feed device according to Fig. 11 in side view; and

[0048] Fig. 13 the seam feeding device according to Figures 11 and 12 in a plan view.

[0049] Fig. 1 shows a sewing machine 1 for forming a circumferential edge seam in a large-area, multi-layered fabric 2 (Figures 8 to 10). The sewing machine 1 has a fabric support 3 and a sewing unit 4. The fabric support 3 consists of two conveyor belts 5 and 6 of different widths, with the conveyor belt 5 being significantly wider than the conveyor belt 6, which is located in the area below the sewing unit 4. At least the conveyor belt 5 is switchable in its conveying direction.

[0050] The sewing machine 1 has a support frame 7.

[0051] The sewing unit 4 has a needle 8 (Figures 8 to 10), a looper (not shown in detail), a presser foot 9 (Figures 8 to 10), and a cutting device 10 (Figures 8 to 10). A transport device 11 is also provided, which has the two conveyor belts 5, 6.

[0052] Furthermore, the sewing machine 1 has, in the area of ​​the sewing unit 4, a holding element 12 that can be placed on the sewing material 2. The holding element 12 is formed with a support element 13, which can be rotated through an angle of 90° from an initial position according to Fig. 8 to an end position according to Fig. 10 relative to the sewing material support 3. From Figures 8 to 10, it can be seen that the support element can be rotated about a pivot point 14, wherein the pivot point 14 is arranged in the immediate vicinity of the needle 8.

[0053] Furthermore, Figures 8 to 10 show a receptacle 15 of the support element 13, which is triangular in plan view. The receptacle 15 is arranged in the region of a cathetus of the support element 13, which is designed as a right-angled triangle. The receptacle 15 of the support element 13 has a straight boundary 16, which in the end position according to Fig. 10 is aligned essentially parallel to a front edge 17 of the presser foot 9. The straight boundary 16 of the receptacle 15 of the support element 13 merges into a region 18 of the outer contour of the support element 13, which region is aligned at right angles to the boundary 16, wherein this region 18 in the end position according to Fig. 10 is aligned parallel to an edge 19 of the presser foot 9 and to an edge region 20 of the sewing material 2.

[0054] Figures 8 to 10 show the process of forming an edge seam in the fabric 2. The conveying direction of the fabric 2 is indicated by the arrow 21 in Fig. 8. When the fabric 2 reaches an end region with its edge region 20, it is necessary for the fabric 2 to be rotated by 90° relative to the fabric support 3 with a view to achieving a continuously formed edge seam. The conveying of the fabric 2 is interrupted and the fabric 2 is rotated relative to the fabric support 3. In this regard, Fig. 9 shows a first step of the rotation by 45° relative to the fabric support 3. It can be seen that a transition in the shape of a circular arc from the region 18 into the second leg 22 of the support element 13 is guided past the presser foot 9. During this rotary movement, the needle 8 can execute further stitches and the cutting device 10 can trim the edge region of the fabric 2. During the turning process according to Fig.9, the sewing material 2 is rotated exclusively around the pivot point 14, but not conveyed according to the arrow 21 in Fig. 8.

[0055] Fig. 10 shows the final position before the start of the sewing process of the edge seam along another longitudinal edge 23 of the sewing material 2. It can be seen that the limit 16 has reached the front edge 17 of the presser foot 9 and the sewing process can be continued in the direction of the arrow 21 in Fig. 10.

[0056] While the next edge seam is now being sewn along the longitudinal edge 23 with the sewing machine 1, the holding element 12 with the support element 13 is removed from the surface of the sewing material 2 and returned from the end position shown in Fig. 10 to the starting position shown in Fig. 8, so that when the end region of the longitudinal edge 23 is reached, the holding element 12 is available for a renewed turning process as described above.

[0057] The support element 13 supports the rotation process of the sewing material 2 in such a way that a large surface area of ​​the sewing material 2 is held in the area of ​​the needle 8 in such a way that folds below the holding element 12 can be avoided, as can a displacement of the sewing material layers of the sewing material 2 relative to one another.

[0058] The rotational movement of the sewing material 2 on the sewing material support 3 is supported by a control of the conveyor belt 5, which is driven counter to the conveying direction according to arrow 21. In addition, the conveyor belt 6 can be driven in the direction of arrow 21.

[0059] Above the sewing material support 3, a triangular support frame 24 is arranged, on which a guide track 25 is formed. The guide track 25 is semicircular and serves to guide at least one guide roller 26. Each guide roller 26 is connected to a cantilever arm 27 of the holding element 12, wherein the two cantilever arms

[0060] 27 are arranged at right angles to one another and, together with the holding element 12, can be placed on the sewing material 2 and moved relative to the sewing material support 3. The cantilever arms 27 are moved together with the support element 13 according to Figures 8 to 10 to support the rotational movement of the sewing material 2 on the sewing material support 3.

[0061] The cantilever arms 27 also serve to prevent undesired creases in the sewing material 2 or undesired displacement of the individual sewing material layers relative to one another during the rotation of the sewing material 2 relative to the sewing material support 3.

[0062] Pneumatic cylinders 28 are provided for the relative movement of the cantilever arms 27 relative to the workpiece support 3. Each cantilever arm 27 is suspended at its end in a guide element 29, which indirectly connects the cantilever arm 27 to the support frame 24. The guide elements 29 are telescopic.

[0063] Figure 1 additionally shows a tensioning element 41 on the cantilever arm 27. The tensioning element 41 is arranged on a surface of the cantilever arm 27 facing the workpiece support 3 and is displaceable relative to the cantilever arm 27 in the longitudinal axis direction of the cantilever arm 27. For this purpose, the cantilever arm 27 can have an undercut groove into which T-shaped guide elements of the tensioning element 41 engage. The relative movement of the tensioning element 41 to the cantilever arm 27 is carried out via a linear motor 42, for example a pneumatic cylinder. When reference is made to tensioning the workpiece 2, this means a crease-free arrangement of the workpiece 2 on the workpiece support 3 without the workpiece 2 being stretched.

[0064] Figures 3 to 5 show a detailed view of the sewing machine 1, wherein the mobility of the holding element 12 is illustrated in Figures 3 to 5. In Figure 3, the holding element 12 is in a raised and wasted position relative to the material support 3. In contrast, Figure 4 shows the holding element 12 in a position in which it is in its intended position before the holding element 12 is lowered onto the material 2. Figures 3 to 5 show a transport device 30 which rests on the material 2 during the sewing process and transports it past the needle 8. This transport device 30 is adjustable in height relative to the material support 3. In Figure 4, the transport device 30 is moved to its highest position, so that the support element 13 can reach the area below the transport device 30 due to the pivoting movement of the holding element 12, before it is then lowered as shown in Figure 4.5 is lowered towards the sewing material support 3 and thus onto the sewing material 2.

[0065] To pivot the holding element 12 from the position shown in Fig. 3 to the position shown in Fig. 4, the sewing machine 1 has a pneumatic cylinder 31, one end of which is connected to an axle 32. The second end of the pneumatic cylinder 31 is supported on the support frame 24.

[0066] The lowering of the support element 13 from the position shown in Fig. 4 to the position shown in Fig. 5 is carried out via pneumatic cylinders 33 which are arranged in a housing 34 of the holding element 12.

[0067] Figures 6 and 7 show the sewing machine 1 according to Figures 3 and 5 in corresponding perspective views.

[0068] The sewing machine 1 additionally has a hem feed device 35, as shown in Figures 11 to 13. The hem feed device 35 serves to convert a textile strip 36 into a U-shaped element in cross-section, in order to then feed this element to the sewing material 2 in the edge region during the sewing process to create an edge seam. The strip 36 rests on the one hand on an upper side of the sewing material 2 and on the other hand on an underside of the sewing material 2, while a connection, preferably U-shaped in cross section, of the two strip elements resting on the surfaces of the sewing material 2 covers the edge of the sewing material 2. The edge seam sews the strip 36 to the sewing material 2.

[0069] For this purpose, the hem feed device 35 has a binding device 37 in which the strip 36 is transferred from its flat orientation into an orientation with a U-shaped cross-section. Furthermore, a drive 38 is provided for conveying the strip 36. The drive 38 pulls the strip 36 from a supply roll 39 and feeds it to the sewing process. In addition, a cutting device 40 is provided with which the strip 36 is cut off at the end of the sewing process, i.e. after sewing all four longitudinal edge regions of the sewing material 2 as well as the four regions between the longitudinal edge regions of the sewing material, which regions can be designed as a curve, for example. However, it can also be provided that a cutting process is carried out after completion of a sewing process for each longitudinal or marginal edge region of the sewing material 2.

[0070] Figure 8 additionally shows two sensors 43. The sensors 43 are arranged in the area of ​​the material support 3 and serve to detect the orientation of the material 2 on the material support 3. The orientation of the material 2 relative to the sewing unit 4 is detected via the sensors 43. If the orientation of the material 2 is correct, the sensors 43 transmit signals regarding the completed rotation of the material 2 to a control system (not shown in detail), which serves to enable a subsequent sewing process along the longitudinal edge of the material 2.

[0071] The sensors 43 are arranged in a line spaced apart from one another and, in combination, serve to detect the orientation of the sewing material 2 with different edge lengths. The distance between the sensors 43 can be adjustable. However, the sensors 43 can also be used to detect the beginning and end of a longitudinal edge region of the sewing material 2 to be sewn.

[0072] Additionally, Figure 8 shows a movable device 44. The device 44 is designed as a pneumatic cylinder and is designed to apply a force to the edge region 20 of the sewing material 2, as needed, slightly displacing the edge region 20. For this purpose, the device 44 has a plate-shaped slider that can be moved toward the edge region 20 when controlled.

[0073] Reference symbol

[0074] 1 sewing machine

[0075] 2 sewing material

[0076] 3 Sewing material support

[0077] 4 sewing unit

[0078] 5 Conveyor belt

[0079] 6 Conveyor belt

[0080] 7 Support frame

[0081] 8 needle

[0082] 9 Presser foot

[0083] 10 Cutting device

[0084] 11 Transport device

[0085] 12 Holding element

[0086] 13 Support element

[0087] 14 Pivot point

[0088] 15 recording

[0089] 16 Limitation

[0090] 17 leading edge

[0091] 18 Area

[0092] 19 edge

[0093] 20 Marginal area

[0094] 21 Arrow

[0095] 22 cathetus

[0096] 23 Longitudinal edge

[0097] 24 Support frame

[0098] 25 guideway

[0099] 26 Leadership role

[0100] 27 cantilever

[0101] 28 pneumatic cylinders

[0102] 29 Guide element

[0103] 30 Transport device

[0104] 31 pneumatic cylinders

[0105] 32 Axis

[0106] 33 Pneumatic cylinder 34 Housing

[0107] 35 Seam feed device

[0108] 36 stripes

[0109] 37 Binding device 38 Drive

[0110] 39 supply roll

[0111] 40 Cutting device

[0112] 41 clamping element

[0113] 42 Linear motor 43 Sensor

[0114] 44 Facility

Claims

AMENDED CLAIMS received by the International Bureau on 26 June 2025 (26.06.2025) 1. Sewing machine (1) for forming a circumferential edge seam in a large-area and preferably multi-layered sewing material (2), such as a mattress board, with a sewing material support (3), a sewing unit (4) having a needle (8), a hook and a presser foot (9), a transport device (11) for the sewing material (2) relative to the sewing unit (4), and a holding element (12) which is movable relative to the sewing material support (3) and can be placed on the sewing material (2), wherein the sewing material (2) is movable in the sewing direction with the transport device (11) and is rotatable about the surface normal of the sewing material support, preferably when the needle is inserted, wherein the holding element (12) has a support element (13) which is rotatable by an angle of rotation from a starting position to an end position relative to the sewing material support (3), characterized in that the support element (13) of the holding element (12) has a,preferably has a receptacle (15) formed as a substantially V-shaped or L-shaped incision, in which the presser foot (9) or the presser foot (9) and the needle (8) are located in the end position.

2. Sewing machine according to claim 1, characterized in that the starting position and the end position are arranged on a circular arc which corresponds to a rotational movement of the support element (13) of 90°.

3. Sewing machine according to claim 1 or 2, characterized in that the holding element (12) has two cantilever arms (27), preferably arranged at right angles to one another, which can be placed on the sewing material (2) together with the support element (13) of the holding element (12) and are movable relative to the sewing material support (3).

4. Sewing machine according to one of claims 1 to 3, characterized in that the holding element (12) is movable parallel to the surface normal of the sewing material support (3) and at an angle perpendicular to the surface normal of the sewing material support (3).

5. Sewing machine according to claim 3, characterized in that on at least one cantilever arm (27) a in the longitudinal axis direction of the cantilever arm (27) a clamping element (41) which is displaceable relative to the cantilever arm (27) is arranged.

6. Sewing machine according to claim 5, characterized in that the clamping element (41) is guided in a groove of the cantilever arm (27) and is movable, preferably continuously, between two end positions via a linear motor (42).

7. Sewing machine according to one of claims 1 to 6, characterized in that the transport device (11) has two conveyor belts (5, 6), of which at least one conveyor belt (6) is reversible in its conveying direction to support the rotation of the sewing material (2) on the sewing material support (3).

8. Sewing machine according to one of claims 1 to 7, characterized in that the receptacle (15) of the holding element (12) has a rectilinear boundary (16) which, in the end position, is aligned substantially parallel to a front edge of the presser foot (9).

9. Sewing machine according to claim 8, characterized in that the rectilinear boundary (16) of the receptacle (15) of the holding element (12) merges into a region (18) of the outer contour of the holding element (12) which is oriented at right angles to the boundary (16) and which, in the end position, is oriented substantially parallel to the edge seam.

10. Sewing machine according to one of claims 1 to 9, characterized in that the sewing unit (4) is assigned a seam feed device (35) which feeds a textile strip (36) to the sewing unit (4) as a comprehensive element to the sewing material (2), which element is sewn to the sewing material (2).

11. Sewing machine according to one of claims 3 to 10, characterized in that the cantilever arms (27) are guided on a support frame (24) arranged above the sewing material support (3), in particular via a roller (26).

12. Sewing machine according to one of claims 3 to 11, characterized in that between the cantilever arms (27) arranged at right angles to one another, a third cantilever arm (27) is arranged in the position of the angle bisector.

13. Sewing machine according to one of claims 1 to 12, characterized in that in the area of ​​the sewing material support (3) at least one sensor (43) is arranged, via which an orientation of a longitudinal edge of the sewing material (2) to be sewn and / or trimmed with the sewing unit (4) parallel to the conveying direction of the sewing material (2) to the sewing unit (4) can be determined.

14. Sewing machine according to claim 13, characterized in that in the area of ​​the sewing material support (3) two sensors (43) arranged at a distance from one another are provided, with which a parallel alignment of the longitudinal edges of the sewing material (2) of different lengths to be sewn and / or trimmed with the sewing unit (4) can be determined.

15. Sewing machine according to one of claims 1 to 14, characterized in that a sewing speed of the sewing unit (4) is controllable as a function of a stitch length, wherein in particular the sewing speed and / or the stitch length is adjustable in a transition region of a first longitudinal edge of the sewing material (2) to be sewn into a second longitudinal edge of the sewing material (2) to be sewn, in order in particular to synchronize a rotational speed of the support element (13) with the sewing speed and / or the stitch length.

16. Sewing machine according to one of claims 1 to 15, characterized by a device (44) which is movable parallel to the sewing material support (3) in the direction of a longitudinal edge of the sewing material (2) which is in a sewing process and which moves a longitudinal edge region of the sewing material (2) acted upon by the device (44) in the direction of the support element (13) before sewing a textile strip (36) to the longitudinal edge region of the sewing material (2).

17. Method for forming a circumferential edge seam and / or for sewing a Hem in or on a large-area and preferably multi-layered sewing material (2), such as a mattress plate or a quilt, which rests on a sewing material support (3) and is fed to a sewing unit (4) having a needle (8), a looper and a presser foot (9), wherein the sewing material (2) is moved relative to the sewing unit (4) by a transport device (11) and rotated by a holding element (12) which is movable relative to the sewing material support (3) and can be placed on the sewing material (2), wherein the sewing material (2) is preferably rotated about the surface normal of the sewing material support (3) with the needle (8) inserted, characterized in that the sewing material (2) is rotated by a support element (13) of the holding element (12) in the position placed on the sewing material (2) by an angle of rotation from a starting position into an end position relative to the sewing material support (3), wherein a,the receptacle (15) of the support element (13), preferably designed as a substantially V-shaped or L-shaped notch, is moved in such a way that the presser foot (9) or the presser foot (9) and the needle (8) are in the end position in the receptacle (15).

18. Method according to claim 17, characterized in that two cantilever arms (27) of the holding element (12), preferably arranged at right angles to one another, are placed on the sewing material (2) and are moved with the sewing material (2) relative to the sewing material support (3).

19. Method according to claim 18, characterized in that the sewing material (2) is tensioned in the region of the longitudinal edge of the sewing material (2) to be sewn by means of a tensioning element (41) which is displaceable in the longitudinal axis direction of the cantilever arm (27) relative to the cantilever arm (27).

20. Method according to one of claims 17 to 19, characterized in that the rotation of the sewing material (2) is carried out at least partially by two conveyor belts (5, 6) of the transport device (11), of which at least one conveyor belt (6) is driven reversibly in its conveying direction to assist the rotation of the sewing material (2) on the sewing material support (3).

21. Method according to one of claims 17 to 20, characterized in that a textile strip (36) is fed to the sewing unit (4) as a comprehensive element from a seam feed device (35), which element is sewn as a seam to an edge region (20) of the sewing material (2).

22. Method according to one of claims 17 to 21, characterized in that a parallel alignment of the longitudinal edges of the sewing material (2) to be sewn and / or trimmed with the sewing unit (4) is detected by a sensor (43) in the region of the sewing material support (3), wherein preferably two sensors (43) arranged at a distance from one another detect a parallel alignment of the longitudinal edges of the sewing material (2) of different lengths to be sewn and / or trimmed with the sewing unit (4).

23. Method according to one of claims 17 to 22, characterized in that the sewing material (2) on the sewing material support (3) is rotated in a first step by the holding element (12) and then in a second step by a conveyor belt (5, 6) in the region of the sewing material support (3).

24. Method according to claim 23, characterized in that the sewing material (2) is rotated by 90° after completion of a seam along a longitudinal edge of the sewing material (2), in particular when the needle (8) is inserted into the sewing material (2), wherein the rotation is preferably carried out over at least 60°, in particular over at least 80° by means of the holding element (12) and otherwise by means of the conveyor belt (5, 6) and the sewing material (2) is aligned with its edge region (20) parallel to the sewing direction for the execution of a further seam along a further longitudinal edge after completion of the rotation.

25. Method according to one of claims 21 to 24, characterized in that in the region of the edge region (20) of the sewing material (2) to be sewn, a narrow strip is cut off to form a straight edge region (20).

26. Method according to one of claims 17 to 25, characterized in that that seams to be executed in the edge region (20) are formed from lockstitches. 1 / 13 2 / 13 3 / 13 9 / 13 11 / 13 Fig. 13

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