TAFT NEEDLE

Description

[0001] The invention relates to a taffeta needle.

[0002] Taffeta needles are used in large numbers in a so-called taffeta machine. The taffeta machine is typically used to insert pieces of thread cut from a supply into the soil. This insertion movement is also called "tafting." These pieces of thread are intended to support the natural grass blades and also provide stabilization, i.e., reinforce the soil.

[0003] The taffeta needle is pressed into the ground in a vertical motion, holding the thread at its tip in a fork-like guide. It is clear that the needle tip is subject to a certain amount of abrasive stress. The needle tip can also be damaged if the ground is not adequately prepared to remove stones and other obstacles.

[0004] Document DE 10 2015 112 329 A1 discloses a taffeta unit for a taffeta machine, a taffeta machine with such a taffeta unit, and a method for inserting yarn sections into a substrate. Yarn sections are cut and transported parallel along a circulating path and inserted into the substrate.

[0005] The document WO 2018 / 074 930 A1 discloses a method for inserting yarns into a substrate using a device.

[0006] It is therefore an object of the present invention to further develop the known taffeta needles in such a way that the effort required in the event of repair or replacement is reduced.

[0007] To achieve this object, the invention is based on a taffeta needle as described above and proposes that the taffeta needle has a needle carrier and a needle tip, wherein the needle tip can be placed on the needle carrier and firmly connected to it and an alignment element is provided on the needle tip, which cooperates with an alignment counter element of the needle carrier for aligning the needle tip on the needle carrier.

[0008] This division of the taffeta needle into two separately manufactured elements allows these two elements to be optimized for their respective areas of application. This means that the entire taffeta needle does not have to be made of the same hard material as the needle tip, which is subject to considerably greater wear. Furthermore, a predetermined breaking function can be implemented in the typically significantly larger needle carrier, which might not be possible in the needle tip. Furthermore, in the event of damage to the needle tip, only the tip needs to be replaced, which can be achieved easily and cost-effectively with an appropriate structural arrangement, as proposed by the invention.

[0009] The arrangement of an alignment element on the needle tip and a counter alignment element on it enables simple, reliable and reproducible definition of the alignment and / or positioning of the needle tip on the needle carrier, especially when changing the needle tip, e.g. in the event of breakage or as a precautionary measure if the ground to be taffetaed is too hard for the inserted needle tip and there is a risk of damage or destruction to the needle tip. The needle tip is placed on the needle carrier and preferably connected with a connecting element. Typically, a locating mandrel is provided on one or the other element for this purpose. The locating mandrel and the communicating counter element can also be equipped with an alignment element, e.g. a flattened, planar surface, thus enforcing a fixed geometric position between the nose tip and the needle carrier, as well as the needle holder of the taffeta machine.A similar result can also be achieved by deviating from a rotationally symmetrical design of the mandrel and its opposite, thus also resulting in an easily repeatable alignment.

[0010] In particular, the aim is for the needle tip to be releasably and firmly mounted on the needle carrier. This means that the needle tip is initially held mechanically stable and firmly by the needle carrier, but this connection can preferably be separated, i.e., detached, without causing any damage (e.g., during maintenance, servicing, or repair).

[0011] The taffeta needle is specifically designed for a taffeta machine, where the taffeta machine is designed to insert or taffeta cut pieces of thread into a base. In a typical taffeta machine, a taffeta needle is guided by an element of the taffeta machine such that the taffeta needle is vertically movable. In a retracted position, the taffeta machine typically picks up a piece of thread, then moves downwards and inserts the piece of thread into a base.

[0012] Different variants are possible regarding the design of the alignment element. For example, a notch can be provided on the circumference, into which a projection of the other element fits. The projection can be provided either on the needle tip or on the needle carrier. The notch is then typically provided on the other element. The same can also be achieved with a tongue-and-groove arrangement, with one element accommodating the tongue and the counter element accommodating the groove.

[0013] According to a preferred embodiment, the alignment element provided on the needle tip and the alignment counter-element arranged on the needle carrier interact in such a way that the needle tip is positioned on the needle carrier in a rotationally precise position. Such a configuration allows different needle tips to be positioned accurately on the needle carrier in the event of replacement. This is preferably achieved by a positive and / or torsion-resistant interaction of the alignment element and the alignment counter-element. In particular, positive locking in the circumferential direction (e.g., oval cross-section, tongue-and-groove arrangement, notch protruding into a recess, etc.) of the rotationally symmetrical taffeta needle is used.

[0014] According to a preferred embodiment, the needle carrier has a receiving mandrel that extends into a receiving opening in the needle tip. The receiving mandrel typically protrudes beyond the rest of the needle carrier. It can, in particular, be designed as a projection.

[0015] A particular advantage of this design is that if a needle tip becomes worn, it can be easily removed, the needle carrier's mandrel can be cleaned, and a fresh needle tip with a clean opening can then be placed on the mandrel. This variant simplifies assembly and, in particular, maintenance of the taffeta needle. Replacing the needle tip is sufficient in most cases for the necessary intervention, thus eliminating the need for complex assembly work.

[0016] According to one embodiment, the needle tip has a receiving mandrel that extends into a receiving opening of the needle carrier. This corresponds to a kinematic reversal of the previously described feature, which is also feasible and offers similar advantages.

[0017] The needle tip preferably has a thread guide. This can be designed, in particular, as a fork- or prong-like thread guide. This allows a piece of thread to be reliably held, especially while it is inserted vertically downward into a substrate during a taffeta process.

[0018] Preferably, the thread guide is located on the side opposite the receiving mandrel or the receiving opening. This allows for a simple design. However, it is also possible to arrange the thread guide at a different location; for example, a thread guide can also be formed along a longitudinal extension of the needle tip.

[0019] In particular, an adhesive, welded, or soldered connection between the needle carrier and the needle tip can be provided. This enables a reliable connection that is easy to establish. These connections can be easily removed if the needle tip becomes worn. However, other connection types are also possible.

[0020] The thread guide can, in particular, have a thread guide plane designed to accommodate the thread piece to be inserted. This allows the thread piece to be held not only in position but also in a defined orientation.

[0021] A thread guide plane can be defined, in particular, with reference to the needle tip or the entire taffeta needle. It can be a plane in which the thread piece extends during proper operation. The thread piece is typically pulled downward by the needle tip during taffeta insertion. The thread piece can form a triangular shape; this triangle is preferably part of the thread guide plane. The term "the thread piece to be inserted is received in the thread guide plane" is not to be understood objectively, but geometrically. The thread guide plane can, in particular, be an imaginary plane.

[0022] The needle carrier can, in particular, have an alignment surface designed to align the taffeta needle in a needle receptacle (of the taffeta machine). The position of the taffeta needle in the needle receptacle ultimately determines the orientation of the thread guide plane. For optimal thread guidance in the taffeta process, the most precise alignment of the thread guide plane is advantageous. The proposed provision of an alignment surface on the needle carrier makes this process considerably easier.

[0023] Preferably, the alignment surface is oriented perpendicular to the thread guide plane. Thread guide planes of all thread pieces to be inserted into a taffeta machine are typically oriented parallel to one another. The taffeta needles, which are typically rotationally symmetrical, are therefore mounted in precisely defined geometric positions. This can be achieved by arranging an alignment surface against which, for example, the taffeta needle is tensioned during assembly. Thus, the alignment of the taffeta needle is fixed, and this geometric relationship is transferred to the needle tip via the alignment element or alignment counter-element. All other spatial arrangements and (acute or obtuse-angled) alignments of the thread guide plane to the alignment surface are also disclosed as essential to the invention.A right-angled arrangement allows good accessibility of the taffeta needle in its needle holder, but without limiting the invention to this.

[0024] Ideally, the taffeta needle is designed to be straight. The needle tip and needle carrier are aligned, meaning their longitudinal axes are identical, and the taffeta needle has no bend or offset, which could potentially lead to the destruction of the taffeta needle under the considerable pressures (up to 65 kN (6.5 t) acting on the 88 needles of a taffeta machine during the taffeta process).

[0025] Furthermore, it is advantageous that the needle carrier and / or needle tip are predominantly, preferably entirely, made of solid material. This design significantly increases the mechanical stability and resilience of the taffeta needle according to the invention.

[0026] The needle carrier preferably has a predetermined breaking point. This can ensure that if it becomes impossible to insert the taffeta needle into the ground, for example, due to a stone or a plate, the needle carrier breaks in a defined manner. This can prevent further damage to a taffeta machine. In particular, the taffeta machine can be designed so that if a taffeta needle breaks at the predetermined breaking point, no further damage occurs, and a relatively simple replacement of the needle carrier is sufficient.

[0027] The predetermined breaking point can be formed, in particular, by a weakening of the material of the needle carrier. This can be a geometric weakening, for example, a constriction. This can ensure a defined break at the predetermined breaking point.

[0028] In particular, the needle carrier can have hardened and unhardened areas, and hardened areas can form a predetermined breaking point. Such hardened areas typically break more quickly under the influence of forces than unhardened areas, which are more likely to withstand the forces due to a defined yielding.

[0029] The needle carrier can, in particular, be designed as a cylindrical base body. This allows for simple production and use. However, other shapes are also possible.

[0030] The ratio of the length of the needle carrier to its diameter can preferably be greater than 40, more preferably greater than 50, and especially preferably greater than 60. This enables an elongated design, which allows for a dense arrangement of taffeta needles. However, other length-to-diameter ratios are also possible. In particular, the needle carrier can have a diameter corresponding to that of the needle tip.

[0031] The needle carrier can be designed as a metal rod made of iron, steel, or an iron alloy. Such materials have proven particularly stable and abrasion-resistant for the relevant application. However, the use of other materials is also possible.

[0032] Preferably, the needle carrier has a Vickers hardness of less than 1000 HV, particularly preferably less than 900 HV, at least in sections. Such hardnesses have proven advantageous for typical applications. The needle carrier can also have such a Vickers hardness throughout.

[0033] The needle tip can preferably be made of iron, steel, iron alloy, ceramic, fiber, or glass fiber-reinforced plastic, especially polyetheretherketone (PEEK). This allows for easy manufacturing and good durability.

[0034] The needle tip can be designed, in particular, as a metal injection molded (MIM) component. This design enables particularly simple and cost-effective production.

[0035] The needle tip can preferably have a Vickers hardness greater than 1000 HV, more preferably greater than 1300 HV, and especially preferably greater than 1400 HV. In particular, the Vickers hardness can be greater than that of the needle carrier. This can accommodate the fact that the needle tip is typically exposed to greater abrasive stress during operation, as it is inserted into the substrate.

[0036] The problem posed at the beginning is also solved by a method for changing the needle tip of a taffeta needle, as described, which is characterized by the sequence of the following steps: Separating the needle carrier and needle tip, in particular by heating the taffeta needle, in particular in the connection area of ​​the needle carrier and needle tip, in such a way that the connecting means firmly connecting the needle carrier and needle tip reduces or loses its connecting force. Removing the needle tip from the needle carrier. In the connection area of ​​the needle carrier and the new needle tip, equipping at least one of the mutually facing contact surfaces of the needle carrier and the new needle tip with a connecting means firmly connecting the elements. Placing a new needle tip on the needle carrier, the needle tip being precisely aligned and positioned in a rotational manner on the needle carrier and held in this position until the connecting means has developed a sufficient connecting force.

[0037] The advantages of the invention described at the beginning with regard to the taffeta needle also apply in the same way to the method now proposed according to the invention.

[0038] In a preferred embodiment of the method, it is provided that before the needle tip is separated from the needle carrier, the mechanical load on the taffeta needle during the taffeta process is determined and, in the event of an impending or existing overload, a change of the taffeta needle or the needle tip is indicated.

[0039] The present application also discloses a variant in which the mechanical load on the taffeta needle is monitored. For example, the hydraulic pressure during the process of setting the taffeta needles and pressing them into the ground is measured and monitored. This is a direct measure of the mechanical stress on the taffeta needles. If their mechanical load exceeds a threshold value, this overload is indicated in a suitable manner, for example, by a measuring device or visually and / or acoustically. In response to this, it is now proposed that either one (or more) taffeta needles be used that can withstand the higher mechanical stresses, or that a needle tip be replaced or inserted on a taffeta needle that can withstand the increased mechanical stresses.

[0040] Furthermore, the invention also includes the use of a taffeta needle having a needle carrier and a needle tip, wherein the needle tip can be placed on the needle carrier and connected thereto in a detachable and secure manner, in particular in a manner that prevents twisting and pulling off, in particular as described in this application, for inserting or taffetaing cut thread pieces into a base, in particular with a taffeta machine.

[0041] This inventive use significantly reduces the effort required to replace the taffeta needles, as these are now often recyclable.

[0042] In this context, it is particularly noted that all features and properties described with respect to the device, i.e., the "taffeta needle," as well as procedures, are also transferable mutatis mutandis with respect to the formulation of the inventive method or use, and can be used within the meaning of the invention and are deemed to be disclosed. The same applies in reverse, meaning that structural features, i.e., features related to the device, mentioned only with respect to the method or use, can also be considered and claimed within the scope of the device claims, relating to the claimed taffeta needle or other objects, and are also considered part of the disclosure.

[0043] The invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1aA taffeta needle in a first position in an external view, Fig. 1bThe taffeta needle of Figur 1a in a cross-sectional view, Fig. 2aThe taffeta needle according to Figur 1a in a second position rotated by 90° around the longitudinal axis in an external view, Fig. 2bThe taffeta needle of Figur 2a in a cross-sectional view.

[0044] Fig. 1a shows an external view of a taffeta needle 1 according to a first embodiment. The taffeta needle 1 has a needle carrier 3 and a needle tip 5. These two elements together form the taffeta needle 1. Overall, the taffeta needle 1 is elongated and has a high length-to-diameter ratio. The taffeta needle 1 can be used, in particular, to grip pieces of thread in a taffeta machine and insert them into a substrate.

[0045] The needle tip 5 is attached to the needle carrier 3 in such a way that it can be detached from the needle carrier 3. This allows the needle tip 5 to be attached to a movable element of a taffeta machine, allowing the needle carrier 3 to perform a defined movement. In particular, this can be a vertical movement.

[0046] The needle tip 5 guides a piece of thread (not shown), which is to be inserted into a substrate. For example, the substrate may contain a stone or a similarly hard element that could damage the needle tip 5. In this case, it is typically sufficient to simply replace the needle tip 5, while the needle carrier 3 can remain in its mounting.

[0047] The needle carrier 3 has an alignment surface 32, which can interact with a fastening of the needle carrier 3. This allows the alignment of the needle carrier 3 relative to a fastening. This involves, on the one hand, a possible rotation about a longitudinal axis, and, on the other hand, a positioning along this longitudinal axis. The alignment surface 32 is designed as a recessed surface, which can be held, for example, by a complementary element.

[0048] The needle tip 5 has an alignment element 50. The needle carrier 3 has a complementary alignment counter-element 30. The alignment element 50 is in the form of a projection. The alignment counter-element 30 is designed as a complementary recess. In this way, it can be ensured that the needle tip 5 placed on the needle carrier 3 has a predetermined orientation relative to the needle carrier 3. This particularly applies to rotation about a longitudinal axis. However, it can also be ensured that the needle tip 5 has been pushed completely onto the needle carrier 3.

[0049] It should be noted that in addition to the embodiment shown, the reverse embodiment is also possible. In particular, the alignment element 50 can be designed as an exception and the alignment counter-element 30 as a projection.

[0050] Fig. 1b shows a cross-sectional view of the taffeta needle 1 of Fig. 1a It can be seen that the needle carrier 3 has a receiving mandrel 31, which engages in a receiving opening 51 of the needle tip 5. This enables a reliable connection between the needle carrier 3 and the needle tip 5. The receiving mandrel 31 extends, as shown, along the longitudinal direction of the entire taffeta needle 1.

[0051] A thread guide 52 is located at the end of the needle tip 5. This serves to securely hold the thread piece and fix its position so that it can be reliably inserted into a substrate. The taffeta needle 1 can move vertically downwards for this purpose, taking the thread piece with it. The thread guide prevents unwanted displacement or removal of the thread piece.

[0052] In the Fig. 2a und 2b is the taffeta needle 1 after Figur 1a, b and rotated 90° around its longitudinal axis.

[0053] The following mainly refers to the differences to the presentation according to Figur 1a , b received.

[0054] In the second embodiment, the alignment element 50 of the needle tip 5 is arranged elongated on the outside. It engages in an external notch, which forms the alignment counter element 30. This also allows the position and alignment of the needle carrier 3 and the needle tip 5 relative to each other to be determined.

[0055] In Fig. 2aA thread guide plane 53 is also shown. The thread piece typically runs in this thread guide plane 53 when it is gripped by the thread guide 52. The thread guide plane 53 is perpendicular to the alignment surface 32. The position and alignment relationship, which is defined by the interaction between the alignment element 50 and the alignment counter-element 30, defines the position of the thread guide plane 53 relative to the alignment surface 32. Thus, when the taffeta needle 1 assumes a defined position and alignment relationship to the taffeta machine by means of the alignment surface 32, the position of a thread piece is also defined.

[0056] In particular, the needle tip 5 and the needle carrier 3 can be manufactured independently of each other. This allows the use of optimized materials and manufacturing processes. List of reference symbols

[0057] 1Taffeta needle 3Needle carrier 5Needle tip 30Alignment counter element 31Holder mandrel 32Alignment surface 50Alignment element 51Holder opening 52Thread guide 53Thread guide plane

Claims

1. Taffeta needle of a taffeta machine, the taffeta machine being intended for inserting cut pieces of thread into a substrate, and the taffeta needle (1) having a needle carrier (3) and a needle point (5), characterized in that the needle point (5) can be placed on the needle carrier (3) and is connected to the latter in a fixed, in particular twist-proof and pull-off-proof, detachable manner, and an alignment element (50) is provided on the needle point (5) and is connected to an alignment counter-element (30) of the needle carrier (3), in particular in such a way that it cannot be twisted or pulled off, and an alignment element (50) is provided on the needle point (5) which interacts with an alignment counter-element (30) of the needle carrier (3) to align the needle point (5) on the needle carrier (3).

2. taffeta needle according to claim 1, characterized in that the alignment element (50) provided on the needle tip (5) and the alignment counter-element (30) arranged on the needle carrier (3) interact in such a way that the needle tip (5) is positioned on the needle carrier (3) in a rotationally precise position.

3. Taffeta needle according to one of the preceding claims, characterized in that the needle carrier (3) has a receiving mandrel (31) which plunges into a receiving opening (51) of the needle point (5) or the needle point (5) has a receiving mandrel which plunges into a receiving opening of the needle carrier (3).

4. taffeta needle according to one of the preceding claims, characterized in that the needle point (5) has a thread guide (52), in particular a fork-like or prong-like thread guide (52).

5. taffeta needle according to one of the preceding claims, characterized in that an adhesive, welded or soldered connection between the needle carrier (3) and the needle point (5) is provided as the connecting means.

6. taffeta needle according to one of the preceding claims, characterized in that the needle carrier (3) has an alignment surface (32) which serves to align the taffeta needle (1) in a needle receptacle.

7. taffeta needle according to claim 6, characterized in that the alignment surface (32) is oriented at right angles to the thread guide plane (53).

8. Taffeta needle according to one of the preceding claims, characterized in that the needle carrier (3) has a predetermined breaking range.

9. Taffeta needle according to claim 8, characterized in that the predetermined breaking area is formed by a material weakening of the material of the needle carrier (3) and / or the needle carrier (3) has hardened and unhardened areas and the hardened area forms a predetermined breaking point.

10. taffeta needle according to one of the preceding claims, characterized in that the ratio of the length of the needle carrier (3) to its diameter is greater than 40, in particular greater than 50, preferably in particular greater than 60.

11. taffeta needle according to one of the preceding claims, characterized in that the needle carrier (3) is designed as a metal rod made of iron, steel or an iron alloy and / or the needle carrier (3) has a Vickers hardness below 1000 HV, in particular below 900 HV, at least in sections.

12. taffeta needle according to one of the preceding claims, characterized in that the needle tip (5) is made of iron, steel, iron alloy, ceramic, fibre or glass fibre reinforced plastic, in particular polyether ether ketone (PEEK) and / or the needle tip (5) is designed as a metal injection moulding (MIM) component and / or the needle tip (5) has a Vickers hardness greater than 1000 HV, in particular greater than 1300 HV, in particular preferably greater than 1400 HV.

13. Method for changing the needle point (5) of a taffeta needle (1) according to one of the preceding claims, characterized by the sequence of the following steps: - Separation of needle carrier (3) and needle point (5) by heating the taffeta needle (1), in particular in the connecting area of needle carrier (3) and needle point (5), in such a way that the connecting means firmly connecting the needle carrier (3) and needle point (5) reduces or loses its connecting force; - Remove the needle tip (5) from the needle carrier (3); - In the connection area of the needle carrier (3) and the new needle tip (5), at least one of the contact surfaces of the needle carrier (3) and the new needle tip (5) facing each other is equipped with a connecting means that firmly connects the elements; - Placing a new needle tip (5) on the needle carrier (3), whereby the needle tip (5) is rotationally aligned and positioned precisely on the needle carrier (3) and held in position until the connecting means has developed a sufficient connecting force.

14. Method according to claim 13, characterized in that before the needle point (5) is separated from the needle carrier (3), the mechanical load on the taffeta needle (1) during the taffetting process is determined and a change of the taffeta needle (1) or the needle point (5) is indicated in the event of an imminent or existing overload.

15. use of a taffeta needle, which has a needle carrier (3) and a needle point (5), wherein the needle point (5) can be placed on the needle carrier (3) and can be releasably fixedly connected thereto, in particular in such a way that it cannot be twisted or pulled off, according to one of the preceding claims 1 to 12, for inserting or dipping cut pieces of thread into a base with a taffeta machine.