TUFTING NEEDLE

Abstract

The invention relates to a tufting needle of a tufting machine, wherein the tufting machine is provided to insert or tuft severed yarn pieces into a ground, and the tufting needle has a needle carrier and a needle tip. The needle tip is able to be placed on the needle carrier and able to be connected to the latter in a fixed manner, in particular so as to be secured against rotation and extraction, and provided on the needle tip is an alignment element which for aligning the needle tip on the needle carrier interacts with an alignment counter element of the needle carrier.

Description

The invention relates to a tufting needle.

Comparatively large numbers of tufting needles are used in a so-called tufting machine. The tufting machine typically serves to insert yarn pieces severed from a yarn supply into a ground. This inserting movement is also referred to as “tufting”. These yarn pieces are intended to support the natural grass blades, on the one hand, and also stabilize, i.e. reinforce, the ground, on the other hand.

In the process, the tufting needle is pushed into the ground in a vertical movement, wherein said tufting needle holds the yarn piece in a fork-type yarn guide at the tip of said tufting needle. It is obvious that the needle tip is subjected to a certain amount of abrasive wear. The needle tip may also be destroyed if the substrate has not been correspondingly prepared, i.e. is free of rocks or obstacles.

It is therefore an object of the present invention to refine the known tufting needles in such a manner that the complexity in the event of repair or replacement is reduced.

In order for this object to be achieved, the invention proceeds from a tufting needle as described at the outset and proposes that the tufting needle has a needle carrier and a needle tip, wherein the needle tip is able to be placed on the needle carrier and able to be connected to the latter in a fixed manner, and provided on the needle tip is an alignment element which for aligning the needle tip on the needle carrier interacts with an alignment counter element of the needle carrier.

This partitioning of the tufting needle into two elements which are to be produced individually permits these two elements to be optimized for their respective field of application. In this way, the entire tufting needle does not have to be composed of the same hard material as the needle tip, the latter after all being subjected to substantially more wear and tear. Moreover, a predetermined breaking function, which could potentially not be implemented in the needle tip, can also be implemented in the usually significantly larger needle carrier. Also, only the needle tip has to be replaced in the event of damage to the latter, this being possible in a simple and cost-effective manner as the result of a corresponding structural arrangement as proposed according to the invention.

The disposal of an alignment element on the needle tip and of an alignment counter element on the needle carrier enables the alignment and/or positioning of the needle tip on the needle carrier to be defined in a simple, reliable and reproducible manner, specifically when replacing the needle tip, for example in the event of a breakage or as a precautionary measure when the ground to be tufted is too hard for the needle tip in use and damage to or destruction of the needle tip is imminent. The needle tip is pushed onto the needle carrier and preferably connected by a connecting device. For this purpose, a receiving mandrel is typically provided on the one element or the other. The receiving mandrel and the counterpart communicating therewith can also be equipped with an alignment element, for example an oblate flat face, and thus enforce a fixed geometrical position between the needle tip and the needle carrier and the needle holder of the tufting machine. This can be achieved in a similar way in that the receiving mandrel and its counterpart deviate from a rotationally symmetrical design embodiment, thereby also resulting in an easily reproducible alignment.

The particular objective is that the needle tip is disposed on the needle carrier in a releasably fixed manner. This means that the needle tip is primarily always held in a stable and fixed manner by the needle carrier, but that this connection can preferably be severed, thus released, in a non-destructive manner (e.g. for servicing, refurbishing or repairing).

The tufting needle is provided in particular for a tufting machine, wherein the tufting machine is provided to insert or tuft severed yarn pieces into a ground. In a typical tufting machine, a tufting needle is guided by an element of the tufting machine such that the tufting needle is vertically movable. In a retracted state, the tufting machine in the process typically picks a yarn piece, then moves downward, and inserts the yarn piece into a substrate.

Different variants in terms of the design embodiment of the alignment element are possible. For example, a notch into which a protrusion of the other element projects can be provided on the circumference. The protrusion can be provided either on the needle tip or on the needle carrier. The notch is then typically provided on the respective other element. The same can also be achieved with a tongue-and-groove assembly in which the tongue is received in one element and the groove is received in the counter element.

According to one preferred embodiment, the alignment element provided on the needle tip and the alignment counter element disposed on the needle carrier interact in such a manner that the needle tip is positioned in a precise rotational position on the needle carrier. Such a design embodiment makes it possible for different needle tips to be positioned accurately on the needle carrier in the event of a replacement. This is preferably achieved by the alignment element and the alignment counter element interacting in a form-fitting manner and/or a co-rotational manner. In particular, the form-fit (e.g. oval cross-section, tongue-and-groove assembly, notch projecting into a recess) is used in the circumferential direction of the rotationally symmetrical tufting needle.

According to one preferred embodiment, the needle carrier has a receiving mandrel which plunges into a receptacle opening of the needle tip. The receiving mandrel typically projects beyond the remaining part of the needle carrier. Said receiving mandrel can in particular be configured as a protrusion.

It is particularly advantageous in this embodiment that in the event of a worn needle tip the latter can be easily disassembled, the receiving mandrel of the needle carrier can be cleaned, and then a fresh needle tip with a clean opening is placed on the receiving mandrel. This variant facilitates the assembling and in particular also the servicing of the tufting needle. In most cases in which an intervention is required, replacing the needle tip is sufficient, as a result of which complex assembling work can be dispensed with.

According to one embodiment, the needle tip has a receiving mandrel which plunges into a receptacle opening of the needle carrier. This corresponds to a kinematic reversal of the feature previously described, which is likewise implementable and is associated with similar advantages.

The needle tip preferably has a yarn guide. The latter can in particular be configured as a fork-type or prong-type yarn guide. In this way, a yarn piece can be reliably held, in particular while the latter is inserted vertically downward into a substrate during a tufting procedure.

The yarn guide is preferably situated on the side that lies opposite the receiving mandrel or the receptacle opening. This enables a simple embodiment. A disposal of the yarn guide on another location is however possible; for example, a yarn guide can also be configured along a longitudinal extent of the needle tip.

An adhesively bonded, welded or soldered connection can in particular be provided as a connecting device between the needle carrier and the needle tip. This enables a reliable connection which is easy to produce. Said connections can also be released again with little complexity in the event of wear on the needle tip. Other types of connections can however also be used.

The yarn guide can in particular have a yarn guide plane which is provided for receiving the yarn piece to be inserted. As a result, the yarn piece cannot only be held in position but also in a defined alignment.

A yarn guide plane can in particular be defined in terms of the needle tip or the entire tufting needle. Said yarn guide plane can in particular be a plane in which the yarn piece extends during orderly operation. When tufting, the yarn piece is typically pulled downward by the needle tip. The yarn piece can form a triangular shape in the process, this triangle preferably being part of the yarn guide plane. The notion that the yarn piece to be inserted is received in the yarn guide plane is not to be understood objectively but geometrically. The yarn guide plane here can in particular be an imaginary plane.

The needle carrier can in particular have an alignment face which is provided to align the tufting needle in a needle holder (of the tufting machine). The position of the tufting needle in the needle holder ultimately determines the orientation of the yarn guide plane. An ideally exact alignment of the yarn guide plane is advantageous with a view to the yarn being optimally guided in the tufting process. This is significantly facilitated by the proposed provision of an alignment face on the needle carrier.

It is preferably provided that the alignment face is oriented so as to be orthogonal to the yarn guide plane. The yarn guide planes of all yarn pieces to be inserted in a tufting machine are typically oriented so as to be mutually parallel. Therefore, the tufting needles which are typically configured so as to be rotationally symmetrical in principle, are assembled is in precisely defined geometric positions. This can be achieved by disposing an alignment face in relation to which the tufting needle is clamped during assembling, for example. In this way, an alignment of the tufting needle is fixedly established, and this geometric correlation is also transmitted to the needle tip by way of the alignment element or the alignment counter element, respectively. All other spatial arrangements and alignments of the yarn guide plane in relation to the alignment face (at acute or obtuse angles) are also disclosed as being relevant to the invention. An orthogonal arrangement permits easy accessibility to the tufting needle in its needle holder, but the invention is not limited thereto.

It is favorably provided that the tufting needle is straight. The needle tip and the needle carrier herein are co-aligned, meaning that their longitudinal axes are identical and the tufting needle is not angled or offset, which could potentially lead to the destruction of the tufting needle at the substantial pressures (a total of up to 65 kN (6.5 t) acts on 88 tufting needles of a tufting machine during the tufting procedure).

It is furthermore advantageous that the needle carrier and/or needle tip are/is predominantly, preferably completely, composed of solid material. This design embodiment significantly increases the mechanical stability and load-bearing capability of the tufting needle according to the invention.

The needle carrier preferably has a predetermined breakage region. The latter can ensure that the needle carrier breaks in a defined manner in the event that it is impossible for the tufting needle to be inserted into the ground, for example owing to a rock or a slab. As a result, further damage to a tufting machine can be avoided. The tufting machine can in particular be constructed such that no further damage arises in the event of a tufting needle breaking at the predetermined breaking point, and a comparatively simple replacement of the needle carrier suffices.

The predetermined breaking region can in particular be configured by a material weakening of the material of the needle carrier. This can in particular be a geometric weakening, for example a constriction. In this way, it can be ensured that breaking in a defined manner takes place at the predetermined breaking point.

The needle carrier can in particular have hardened and non-hardened regions, and hardened regions can configure a predetermined breaking point. Under the influence of forces, hardened regions of this type typically break faster than non-hardened regions, the latter being better able to withstand the forces by way of a defined resilience.

The needle carrier can in particular be configured as a cylindrical main body. This enables simple production and use. However, other shapes are also possible.

The ratio between the length of the needle carrier and the diameter of the latter can preferably be more than 40, furthermore preferably more than 50, and particularly preferably more than 60. This enables an elongate embodiment which makes it possible for tufting needles to be disposed in dense rows. In principle, however, other length-to-diameter ratios are also possible; in particular, the needle carrier may have a diameter which corresponds to that of the needle tip.

The needle carrier can in particular be configured as a metal bar from iron, steel or an iron alloy. Materials of this type have proven to be particularly stable and wear-resistance for the specific use of relevance here. However, the use of other materials is also possible.

The needle carrier at least in portions preferably has a Vickers hardness of less than 1000 HV, particularly preferably less than 900 HV. Hardnesses of this type have proven to be advantageous for typical applications. The needle carrier in its entirety may also have such a Vickers hardness.

The needle tip can preferably be composed of iron, steel, iron alloy, ceramic, fiber or glass fiber-reinforced plastics material, in particular polyether ether ketone (PEEK). This enables simple producibility and good durability.

The needle tip can in particular be configured as a metal injection molding (MIM) component. Such an embodiment enables a particularly simple and cost-effective production.

The needle tip can preferably have a Vickers hardness of more than 1000 HV, furthermore preferably more than 1300 HV, particularly preferably more than 1400 HV. The Vickers hardness may in particular be more than that of the needle carrier. In this way, it can be taken into account that the needle tip is typically subjected to greater abrasive stress during operation, because said needle tip is introduced into the substrate.

The object set at the outset is also achieved by a method for replacing the needle tip of a tufting needle as described, said method being distinguished by the sequence of the following steps:

• • separating the needle carrier and the needle tip, in particular by heating the tufting needle, in particular in the connecting region of the needle carrier and the needle tip, in such a manner that the connecting device fixedly connecting the needle carrier and the needle tip reduces or loses its connecting force;
  • removing the needle tip from the needle carrier;
  • equipping at least one of the mutually facing contact faces of the needle carrier and the new needle tip in the connecting region of the needle carrier and the needle tip with a connecting device that fixedly connects the elements;
  • placing a new needle tip on the needle carrier, wherein the needle tip is precisely rotationally aligned and positioned, and held in position, until the connecting device has developed a sufficient connecting force.

The advantages of the invention described at the outset in the context of the tufting needle apply in analogous manner also to the method according to the invention proposed here.

In one preferred design embodiment of the method, it is provided that prior to separating the needle tip from the needle carrier the mechanical stress on the tufting needle during the tufting procedure is determined and a replacement of the tufting needle or of the needle tip is prompted in the event of an imminent or existing overload.

The present application also discloses a variant in which the mechanical stress of the tufting needle is monitored. For example, the hydraulic pressure when lowering the tufting needles and pushing the latter into the ground is measured and monitored. This is a direct measure for the mechanical stress of the tufting needles. If the mechanical stress of the latter exceeds a threshold value, this overload is suitably displayed, for example indicated by a measuring apparatuses or else displayed optically and/or acoustically. As a response thereto it is now proposed that either one tufting needle (or a plurality of tufting needles) which withstands/withstand the high mechanical stresses are/is inserted, or else a needle tip which in turn withstands the increased mechanical stresses is replaced/inserted on a tufting needle.

The invention furthermore comprises the use of a tufting needle which has a needle carrier and a needle tip, wherein the needle tip is able to be placed on the needle carrier and able to be connected to the latter in a releasably fixed manner, in particular so as to be secured against rotation and extraction, in particular as described in this application, for inserting and/or tufting severed yarn pieces into a ground, in particular using a tufting machine.

This use according to the invention significantly reduces the expense of replacing the tufting needles, because the latter are now often able to be recycled.

In this context it is pointed out in particular that all features and properties or else procedural methods described in the context of the device, thus the “tufting needle”, can be applied in an analogous manner to the wording of the method or use according to the invention, and can thus be used in the context of the invention and are considered included in the disclosure. The same applies conversely, meaning that features in terms of the construction, thus the device, which have been mentioned only in the context of the method or the use, can also be considered and claimed in the context of the claims directed toward the device and referring to the claimed tufting needle or other subject matter, and are likewise included in the disclosure.

The invention will now be described in more detail by way of the appended drawings in which:

FIG. 1a: shows a tufting needle in a first position, in an external view;

FIG. 1b: shows the tufting needle of FIG. 1a in a cross-sectional view;

FIG. 2a: shows the tufting needle as per FIG. 1a in a second position which is rotated by 90° about the longitudinal axis, in an external view; and

FIG. 2b: shows the tufting needle of FIG. 2a in a cross-sectional view.

FIG. 1a shows a tufting needle 1 according to a first exemplary embodiment in an external view. The tufting needle 1 has a needle carrier 3 and a needle tip 5. These two elements conjointly form the tufting needle 1. Overall, the tufting needle 1 is elongate and has a high length-to-diameter ratio. The tufting needle 1 can in particular be used for gripping yarn pieces in a tufting machine and inserting said yarn pieces into a substrate.

The needle tip 5 is fastened to the needle carrier 3 such that said needle tip 5 is releasable from the needle carrier 3. This makes it possible for the needle tip 5 to be fastened to a movable element of a tufting machine such that the needle carrier 3 can perform a defined movement. This can in particular be a vertical movement.

In the process, the needle tip 5 guides a yarn piece which is not illustrated and is to be inserted into a substrate. In that respect, it can happen that the substrate has a rock or a similarly hard element which may damage the needle tip 5. In this event, it is typically sufficient for only the needle tip 5 to be replaced, whereas the needle carrier 3 may remain in its fastening.

The needle carrier 3 has an alignment face 32 which can interact with a fastening of the needle carrier 3. This makes it possible for an alignment of the needle carrier 3 relative to a fastening to be established. On the one hand, this is a potential rotation about a longitudinal axis, but on the other hand also a positioning along this longitudinal axis. The alignment face 32 here is embodied as a recessed face which can be held by a complimentary element, for example.

The needle tip 5 has an alignment element 50. The needle carrier 3 has an alignment counter element 30 which is complementary thereto. The alignment element 50 presently is configured in the form of a protrusion. The alignment counter element 30 is configured as a clearance which is complementary thereto. It can be ensured in this way that the needle tip 5 pushed onto the needle carrier 3 has a defined orientation relative to the needle carrier 3. This relates in particular to the rotation about a longitudinal axis. However, it can also be ensured in this way that the needle tip 5 has been completely pushed onto the needle carrier 3.

It is to be pointed out that, in addition to the embodiment shown, the reverse embodiment is also possible. In particular, the alignment element 50 can be configured as a clearance, and the alignment counter element 30 can be configured as a protrusion.

FIG. 1b shows a cross-sectional view of the tufting needle 1 of FIG. 1a. It can be seen here that the needle carrier 1 has a receiving mandrel 31 which engages in a receptacle opening 51 of the needle tip 5. This enables a reliable connection between the needle carrier 3 and the needle tip 5. As is shown, the receiving mandrel 31 extends along the longitudinal direction of the entire tufting needle 1.

A yarn guide 52 is disposed on the end side of the needle tip 5. Said yarn guide 52 serves to securely hold the yarn piece and to fix the latter in terms of its position to the extent that said yarn piece can be reliably inserted into a substrate. For this purpose, the tufting needle 1 can move vertically downward and entrain the yarn piece in the process. Any undesirable displacement or removal of the yarn piece is prevented by the yarn guide.

In FIGS. 2a and 2b, the tufting needle 1 as per FIG. 1a, b is shown as and rotated by 90° about its longitudinal axis. The points of differentiation in comparison to the illustration as per FIG. 1a, b are substantially discussed hereunder.

The alignment element 50 of the needle tip 5 in the second exemplary embodiment is disposed so as to be elongate on the external side. Said alignment element 50 engages in an external notch which forms the alignment counter element 30. The position and the alignment of the needle carrier 3 and the needle tip 5 relative to one another can also be established as a result.

Moreover, a yarn guide plane 53 is plotted in FIG. 2a. The yarn piece, when gripped by the yarn guide 52, typically runs in this yarn guide plane 53. The yarn guide plane 53 here is orthogonal to the alignment face 32. The position of the yarn guide plane 53 relative to the alignment face 32 is defined by the correlation of position and alignment that is defined by the interaction between the alignment element 50 and the alignment counter element 30. When the tufting needle 1 by means of the alignment face 32 assumes a defined correlation of position and alignment in relation to the tufting machine, the position of a yarn piece is thus also defined.

The needle tip 5 and the needle carrier 3 can in particular be manufactured independently of one another. This permits the use of materials and production methods which are in each case optimized.

The invention is not limited to any of the embodiments described above but may be modified in many ways.

All of the features and advantages, including constructive details, spatial arrangements and method steps, which are derived from the claims, the specification and the drawings can be essential to the invention individually as well as in a wide variety of combinations.

LIST OF REFERENCE SIGNS

• • 1 Tufting needle
  • 3 Needle carrier
  • 5 Needle tip
  • 30 Alignment counter element
  • 31 Receiving mandrel
  • 32 Alignment face
  • 50 Alignment element
  • 51 Receptacle opening
  • 52 Yarn guide
  • 53 Yarn guide plane

Claims

1. A tufting needle of a tufting machine, wherein the tufting machine is provided to insert or tuft severed yarn pieces into a ground, and the tufting needle has a needle carrier and a needle tip, characterized in that the needle tip is able to be placed on the needle carrier and able to be connected to the latter in a fixed manner, in particular so as to be secured against rotation and extraction, and provided on the needle tip is an alignment element which for aligning the needle tip on the needle carrier interacts with an alignment counter element of the needle carrier.

2. The tufting needle as claimed in claim 1, characterized in that the alignment element provided on the needle tip and the alignment counter element disposed on the needle carrier interact in such a manner that the needle tip is positioned in a precise rotational position on the needle carrier.

3. The tufting needle as claimed in claim 1, characterized in that the needle carrier has a receiving mandrel which plunges into a receptacle opening of the needle tip, or the needle tip has a receiving mandrel which plunges into a receptacle opening of the needle carrier.

4. The tufting needle as claimed in claim 1, characterized in that the needle tip has a yarn guide, in particular comprising a fork-type or prong-type yarn guide, wherein the yarn guide has in particular a yarn guide plane which is provided for receiving the yarn piece to be inserted.

5. The tufting needle as claimed in claim 1, characterized in that an adhesively bonded, welded or soldered connection is provided as a connecting device between the needle carrier and the needle tip, and/or the tufting needle is straight.

6. The tufting needle as claimed in claim 1, characterized in that the needle carrier has an alignment face which serves for aligning the tufting needle in a needle holder, and/or the needle carrier has a predetermined breaking region.

7. The tufting needle as claimed in claim 6, characterized in that the alignment face is oriented so as to be orthogonal to the yarn guide plane.

8. The tufting needle as claimed in claim 1, characterized in that the needle carrier and/or needle tip are/is composed of solid material.

9. The tufting needle as claimed in claim 6, characterized in that the predetermined breaking region is configured by a material weakening of the material of the needle carrier, and/or the needle carrier is configured as a cylindrical main body, and/or the needle carrier has hardened and non-hardened regions and the hardened region forms a predetermined breaking point.

10. The tufting needle as claimed in claim 1, characterized in that the ratio between the length of the needle carrier and the diameter of the latter is more than a range of 40 to 60.

11. The tufting needle as claimed in claim 1, characterized in that the needle carrier is configured as a metal bar from iron, steel or an iron alloy, and/or the needle carrier at least in portions has a Vickers hardness of less than 1000 HV, in particular of less than 900 HV.

12. The tufting needle as claimed in claim 1, characterized in that the needle tip is composed of iron, steel, iron alloy, ceramic, fiber or glass fiber-reinforced plastics material, in particular polyether ether ketone (PEEK), and/or the needle tip is configured as a metal injection molding (MIM) component, and/or the needle tip has a Vickers hardness of more than a range of 1000 HV to 1400 HV.

13. A method for replacing the needle tip of the tufting needle as claimed in claim 1, characterized by the sequence of the following steps: separating the needle carrier and the needle tip, in particular by heating the tufting needle, in particular in the connecting region of the needle carrier and the needle tip, in such a manner that the connecting device fixedly connecting the needle carrier and the needle tip reduces or loses its connecting force;removing the needle tip from the needle carrier;equipping at least one of the mutually facing contact faces of the needle carrier and the new needle tip in the connecting region of the needle carrier and the needle tip with a connecting device that fixedly connects the elements;placing a new needle tip on the needle carrier, wherein the needle tip is precisely rotationally aligned and positioned, and held in position, on the needle carrier until the connecting device has developed a sufficient connecting force.

14. The method as claimed in claim 13, characterized in that prior to separating the needle tip from the needle carrier the mechanical stress on the tufting needle during the tufting procedure is determined and a replacement of the tufting needle or the needle tip is prompted in the event of an imminent or existing overload.

15. A method for using a tufting needle which has a needle carrier and a needle tip, wherein the needle tip is able to be placed on the needle carrier and able to be connected to the latter in a releasably fixed manner, in particular so as to be secured against rotation and extraction, in particular as claimed in claim 1, for inserting or tufting severed yarn pieces into a ground, in particular using a tufting machine.