Tufting machine and method for incorporating yarn strands into a substrate

Description

[0001] The invention relates to a tufting machine and an associated method for inserting yarn strands into a substrate.

[0002] Tufting machines are typically used to embed strands of yarn into a substrate. Such a substrate might be, for example, soil or other material covering the ground, which is to be transformed into artificial turf or at least partially artificial grass by embedding the yarn strands. Tufting machines are also used for the maintenance or improvement of such surfaces.

[0003] Tufting machines are typically large and heavy devices that are moved across the area to be processed. This can be done using their own drive or by using a towing vehicle. Depending on the required accuracy of positioning the yarn strands, it may be necessary in known designs to stop the tufting machine to perform a tufting operation. Only in this case is it ensured that a mechanism for inserting yarn strands does not move during the insertion process. In practice, this has proven to be time-consuming, as the tufting machine has to be stopped and restarted each time.

[0004] WO 2017 017 237 A1 discloses a taffeta unit for a taffeta machine for a method of inserting gamma sections into a subsoil, wherein the gamma sections are cut off and transported parallel along a orbit and subsequently inserted into the subsoil.

[0005] WO 2019 027 317 A1 describes a device configured for installing artificial turf sections into the ground. The device comprises a frame, a plurality of spools with strands of artificial grass on them, and a rotating device attached to the frame that rotates about a substantially horizontal axis. The rotating device is configured to pick up a plurality of strands of artificial grass from the spools and rotate these strands with the movement of the rotating device. The rotating device further has a plurality of clamps configured to hold a series of strands of artificial grass between a front clamp and a rear clamp, and a cutting device for cutting the clamped strands. The strands of artificial grass are inserted into the ground by means of an insertion device.

[0006] A device for introducing synthetic fibers into the soil according to WO 2017 183 977 A1 comprises a vehicle with a frame, several rotatable rollers on which synthetic fibers are wound, conveying means for conveying the fibers from the rollers to the respective insertion positions above the soil, pin-shaped insertion elements arranged in at least one row above the fibers at the insertion positions, and first means of movement for moving the insertion elements up and down. The conveying means include a number of clamping elements, the clamping elements being provided on connecting elements. The device further comprises means for cutting the fibers and guide means for moving the connecting elements provided with the clamping elements in an endless path. The pin-shaped insertion elements extend within the endless path, at least in the upper position. The connecting elements are pivotally connected to one another.

[0007] WO 2018 074 930 A1 discloses a method for introducing fibers into the soil using a device. After providing a thread-like fiber, it is positioned under a fiber insertion pin of the device. The fiber insertion pin is then moved downwards and upwards, pressing the fiber into the soil during the downward portion of the movement. The fiber insertion pin is then moved parallel to and above the soil over a step length in one direction of movement, and the aforementioned steps are then repeated.

[0008] It is an object of the invention to provide a tufting machine which, compared to known designs, is implemented in an alternative or improved manner, for example, by avoiding the need to stop for inserting yarn strands. It is a further object of the invention to provide an associated method.

[0009] This is achieved according to the invention by a tufting machine and a method according to the respective main claims. Advantageous embodiments are claimed in the dependent claims.

[0010] The invention relates to a tufting machine. The tufting machine has a frame. The tufting machine has a drive unit configured to move the frame along a surface at least in a forward direction. The tufting machine has a tufting unit configured to insert a number of yarn strands into the surface during each tufting operation. The tufting machine has a horizontal movement unit configured to move the tufting unit relative to the frame at least in the opposite direction to the forward direction during a tufting operation.

[0011] Using such a tufting machine, the tufting unit can be moved relative to the frame. This allows the frame to move across a surface at a constant speed while the tufting unit remains in a fixed position relative to the surface for a specific period of time. This enables the tufting process to take place at that position without any change in the tufting unit's position. In this way, the need for constant stopping and starting of the tufting machine is avoided.

[0012] The frame can be understood as the basic structure of the tufting machine. It can, in particular, form wholly or partially the outer boundary of the tufting machine. The drive unit can, for example, be electric, enabling the tufting machine to be moved across the surface using electrical energy. The drive unit can be designed for forward motion only, or for forward and reverse motion, and / or for controlling the direction of the tufting machine. The drive unit can also be designed as a towing vehicle or as a means of coupling to a towing vehicle.

[0013] The tufting unit is typically the unit that performs the actual insertion of yarn strands. It may be functionally connected to other components of the tufting machine, such as a yarn feeder, power supply components, or control components. Within the tufting machine, the tufting unit is typically distinguished from other components by its horizontal and, typically, also vertical movement, particularly relative to the frame.

[0014] The horizontal motion unit typically includes components for guiding the tufting unit during its movement relative to the frame. This ensures that this movement occurs as desired.

[0015] The horizontal movement unit can be configured, in particular, to move the tufting unit relative to the frame in the opposite direction to the forward direction at the same speed as the drive unit moves the frame forward on the substrate during a tufting operation. This allows the tufting unit to be held in precisely the same position relative to the substrate during the tufting process. Specifically, a control system can be configured to execute such a movement. However, other types of relative movement are also fundamentally possible.

[0016] The horizontal movement unit can be designed, in particular, to hold the tufting unit in one position, especially a constant position, on the substrate during a tufting process, while the drive unit moves the frame. This ensures that there is no relative movement of the tufting unit to the substrate during the tufting process. This results in the insertion of yarn strands at a defined position.

[0017] The horizontal movement unit can be specifically designed to move the tufting unit forward relative to the frame between two consecutive tufting operations. This allows the tufting unit to be brought into a starting position from which it can be moved again in the opposite direction to hold it in a defined position on the substrate during a tufting operation.

[0018] The horizontal movement unit can be specifically designed to move the tufting unit relative to the frame at least 1.5 times faster and / or at most three times faster, or twice as fast, in the forward direction between two immediately successive tufting operations as the drive unit moves the frame forward on the substrate. This ensures that the tufting unit returns to its starting position in a timely manner.

[0019] The horizontal movement unit can be specifically designed to move the tufting unit relative to the frame from a starting position to an end position during a tufting process, and to move it from the end position to the starting position between two consecutive tufting processes. The starting position is typically the position from which the tufting unit is held at a defined location relative to the substrate. The tufting process should be completed no later than when the end position is reached. The tufting unit is then returned to its starting position.

[0020] The horizontal movement unit can be specifically designed to move the tufting unit linearly relative to the frame. This ensures proper guidance of the tufting unit. Linear guidance, in particular, ensures a constant height relative to the substrate.

[0021] It should be mentioned that, in particular, a control system can be configured and / or programmed to control components such as the hydraulic cylinders mentioned below, so that the described movement sequences are carried out.

[0022] The horizontal motion unit may, in particular, have a number of guide rails for linearly guiding the tufting unit in and against the forward direction. The guide rails are typically oriented horizontally, especially if the frame rests on a horizontal surface. They may also be referred to as horizontal rails. This has proven to be a sensible and practical approach for guiding the tufting unit. However, other guiding mechanisms may also be used.

[0023] The horizontal motion unit can, in particular, have at least a number of linear bearings on a first side and on a second side of the tufting unit, preferably at least eight linear bearings on each side, preferably twelve linear bearings on each side. Such numbers of linear bearings have proven to provide reliable guidance for the tufting unit. However, the use of more or fewer linear bearings is also possible.

[0024] In particular, each linear bearing can engage with one of the guide rails. This can mean, in particular, that in the assembled state, parts of the guide rail are positioned both above and below the respective linear bearing. This ensures vertical guidance both upwards and downwards at every point of contact between the linear bearing and the linear rail. Uncontrolled vertical movement of the tufting unit can thus be prevented.

[0025] Alternatively, it may be provided that some or all linear positions are arranged only above or only below the respective guide rail.

[0026] The tufting machine can, in particular, have an inner frame. The inner frame can, in particular, be arranged within the frame and, in particular, be vertically movable relative to the frame. The guide rails can, in particular, be attached to an inner frame. The tufting process can, in particular, be carried out by a vertical movement of the inner frame. During a tufting process, the inner frame is thus moved vertically, which carries the guide rails attached to it. The engaging linear bearings, which are attached to the tufting unit, also move the tufting unit vertically. Simultaneously, a horizontal relative movement of the tufting unit relative to the frame can be achieved.

[0027] The tufting machine can, in particular, have one or more vertical drives designed to move the inner frame vertically relative to the frame in order to perform a tufting operation. These vertical drives can, in particular, be hydraulic cylinders. The vertical drives can, in particular, be connected to the frame and to the inner frame. The inner frame can, in particular, be guided in the frame by means of one or more tufting rails, which can also be referred to as vertical rails and which are, in particular, vertically oriented, so that it is movable in one dimension vertically within the frame. In other words, the tufting machine can have one or more tufting rails that keep the inner frame movable vertically relative to the frame and, in particular, keep it movable exclusively vertically.

[0028] The linear bearings and / or guide rails can be aligned horizontally within the frame. This allows for horizontal movement of the tufting unit relative to a horizontally oriented frame. As a result, the tufting unit is also moved horizontally relative to the floor. This prevents any change in height.

[0029] The horizontal motion unit, in particular its components, can be arranged on the right and left sides of the tufting unit when viewed in the forward direction. This allows for a space-saving arrangement, which avoids further increasing the length of the device, which is typically already significantly longer than it is wide. Specifically, components of the horizontal motion unit can be arranged between the inner frame and the tufting unit.

[0030] The horizontal motion unit may, in particular, include components that can initiate movement of the tufting unit relative to the frame. These components may, in particular, be designed to exert a force that moves the tufting unit relative to the frame and / or relative to the inner frame.

[0031] The motion unit can, for example, include a number of hydraulic cylinders, a spindle drive, a linear actuator, and / or an electric actuator to move the tufting unit relative to the frame. This has proven to be a reliable drive method. However, other types can also be used.

[0032] The horizontal motion unit, or motion unit, can, for example, have four horizontal hydraulic cylinders for moving the tufting unit relative to the frame, specifically on each of the two sides. Such hydraulic cylinders can move the tufting unit efficiently and without jamming. However, a different number of hydraulic cylinders can also be used. The term "horizontal hydraulic cylinders" serves, in particular, to distinguish them from the hydraulic cylinders mentioned above, which provide vertical movement of the inner frame.

[0033] In particular, each horizontal hydraulic cylinder can be attached to the inner frame on one side and to a cylinder mount on the other, which is rigidly connected to the tufting unit. This allows the respective horizontal hydraulic cylinder to move the tufting unit horizontally relative to the inner frame.

[0034] The cylinder receptacles can be arranged, in particular, directly below or above a linear bearing. Specifically, this can be understood to mean that the respective cylinder receptacle is arranged such that a portion of the guide rail, into which the linear bearing engages, engages between the linear bearing and the cylinder receptacle.

[0035] The tufting machine can, in particular, include a position detection unit for determining the position of the tufting unit relative to the frame. This allows the position of the tufting unit relative to the frame to be determined, for example, along a predefined path. This facilitates the control and monitoring of the tufting unit.

[0036] The position detection unit can, in particular, comprise a rotary encoder and a rack, wherein, during horizontal movement of the tufting unit relative to the inner frame and / or the frame, the rotary encoder and rack perform a relative movement to each other, which is detected by the rotary encoder. This allows for simple and reliable determination of the tufting unit's position, even under harsh operating conditions. However, other configurations can also be used.

[0037] The drive unit can be specifically designed to move the frame 10 mm to 50 mm during a tufting process. This has proven to be a practical value for how far the tufting unit can be moved during a tufting process without disrupting it. However, other values ​​are also possible in principle.

[0038] The tufting unit can be specifically designed to perform a tufting operation within a minimum of 1 second and / or a maximum of 2.5 seconds, or 1.5 seconds. This has proven to be a practical timeframe or duration for a tufting operation. Within this timeframe, the operations necessary for inserting yarn strands can typically be carried out. However, other durations can also be used in principle.

[0039] The tufting machine can, for example, have a measuring wheel to detect the movement of the frame on the surface. Using such a measuring wheel, the actual speed of the tufting machine on the surface can be determined. This can be used to control the relative movement of the tufting unit relative to the frame.

[0040] The tufting machine can further include a control device that controls the horizontal movement unit depending on the movement of the frame on the substrate. In particular, the aforementioned movement unit can be controlled. Data generated by the aforementioned measuring wheel and / or the position detection unit can be used for this control.

[0041] The horizontal movement unit and / or the tufting unit can be height-adjustable, particularly relative to the frame. This allows for height adjustment, enabling the tufting unit to be easily adapted to different desired heights and / or different soil conditions or other circumstances. The height adjustability can be achieved hydraulically.

[0042] In particular, the tufting unit can have a number of tufting needles which perform a tufting process when moved vertically. This vertical movement allows for the insertion of yarn strands. The tufting needles are typically significantly longer than their diameter, enabling the insertion of yarn strands without damaging the substrate.

[0043] The drive unit can be specifically designed to move the frame forward at a constant speed. This allows for smooth movement of the tufting machine.

[0044] In particular, the drive unit can have a number of tracked undercarriages. Such tracked undercarriages have proven effective for the application relevant here, as they allow even heavy loads to be moved across a surface without damaging it. However, other designs can also be used.

[0045] The invention further relates to a method for introducing yarn strands into a substrate, wherein the method comprises the following steps repeated several times: ▪ Inserting the yarn strands into the substrate using a tufting unit which is held in a frame, ▪ moving the frame in a forward direction and moving the tufting unit relative to the frame and at least against the forward direction such that the tufting unit remains in the same position on the substrate, then ▪ further moving the frame on the substrate, moving the tufting unit relative to the frame into a starting position for the next insertion of the yarn strands.

[0046] The process can be carried out in particular using a tufting machine described herein. All described designs and variants of the tufting machine can be used. The advantages already mentioned can be achieved. In particular, the frame of the tufting machine can be moved across a substrate at a constant speed, and yet the tufting unit can be kept in the same position relative to the substrate during each tufting operation.

[0047] It should be noted that a tufting machine has a mass of, for example, more than 8 tons and may be subject to the requirement of advancing exactly 20 mm and stopping again with each cycle. In this case, a tufting operation can be carried out with the machine stationary. The forward motion is achieved, for example, by means of two tracked carriages that are electrically controlled and hydraulically driven.

[0048] Experience with known tufting machine designs has shown that the desired value is often difficult to achieve. For example, the tufting machine may stop too early or too late.

[0049] To prevent the tufting machine from starting and stopping abruptly, the procedure described here ensures that it maintains a constant motion. This is achieved by moving the tufting unit back and forth using a linear motion. A horizontal motion unit, for example, is located within the frame of the base unit and is vertically adjustable. The tufting unit can be attached to the horizontal motion unit using linear bearings. The horizontal motion unit can be positioned on the right and left sides of the tufting unit in the direction of travel. Two guide rails can be attached to the horizontal motion unit. The eight linear bearings on each side and the guide rails enable the linear (horizontal) movement of the tufting unit. Horizontal movement of the tufting unit can be achieved, for example, using four hydraulic cylinders, one on each side.A rotary encoder can scan a rack and pinion and determine the position of the tufting unit within the base unit.

[0050] While the base unit moves forward, the tufting unit can move in the opposite direction at the same speed. Once the tufting process is complete and the needles are no longer on the floor, the tufting unit can move forward again. For example, twice the speed can be used for this. When the tufting unit reaches the next starting point, which might be 20 mm further forward than the last tufting process, for example, the tufting unit moves back in the opposite direction to the base unit at the same speed.

[0051] A control system for the tufting machine can align the position between a measuring wheel on the base unit and rotary encoders of the tufting unit.

[0052] The invention will now be explained with reference to the attached figures. These show: Fig. 1 a tufting machine, Fig. 2 a tufting unit, Fig. 3 an inner frame, Fig. 4 a part of the inner frame, Fig. 5 a tufting unit, and Fig. 6 an inner frame and a tufting unit.

[0053] Fig. 1 Figure 1 shows a tufting machine 10 according to an embodiment of the invention. The tufting machine 10 has a frame 20, which at least substantially forms an outer boundary of the tufting machine 10 and to which the other components are attached. For movement on a surface not shown, the tufting machine 10 has a drive unit 21 with a tracked chassis 22. This is electrically driven and thus generates propulsion on the surface. A normal direction of movement of the in Fig. 1 The tufting machine 10 shown is configured in particular such that it moves to the left. A front chassis 23, which has steerable wheels, serves to control the direction of travel.

[0054] A door 25 is formed within the frame 20. This door allows an operator to enter the tufting machine 10. During operation, this operator is typically inside the tufting machine 10 and operates components located within it. For example, components such as coils, valves, an oil tank, or drive motors are located inside the tufting machine 10, or within the frame 20.

[0055] A measuring wheel 24 is attached to the frame 20 and rotates on the ground to precisely record the movement of the frame 20. This allows accurate information about the movement to be obtained at any time. The measuring wheel 24 is connected to a rotary encoder.

[0056] The tufting machine 10 has a tufting unit 30. The tufting unit 30 will be described in more detail below. It serves to insert several yarn strands into the substrate, these yarn strands typically being cut from stored yarns and then inserted into the substrate. Typically, numerous yarn strands are inserted in parallel.

[0057] At one rear end, the tufting machine 10 has a smoothing wheel 26. This serves to smooth the floor or substrate after the insertion of yarn strands. In particular, it can be lowered and / or pressed downwards.

[0058] Fig. 2 The figure shows the tufting unit 30 in greater detail. The perspective is from the front, against the typical direction of travel. It can be seen that the tufting unit 30 has several tufting needles 31 arranged side by side and aligned parallel to each other. The tufting needles 31 can be moved vertically simultaneously and in parallel to carry out the insertion process. This will be discussed in more detail below.

[0059] On the left and right sides of the Fig. 2 Vertical tufting rails 42 are arranged for this purpose, corresponding to the left and right sides in a front view of the tufting machine 10. These are not attached directly to the tufting unit 30, but to an inner frame which is located in Fig. 3 The tufting rails 42 allow the tufting unit 30, and thus the tufting needles 31, to perform a guided vertical movement. The tufting unit 30 is guided and stabilized by the tufting rails 42, in particular such that the position of the in Fig. 3 The inner frame shown in frame 20 remains unchanged forwards, backwards, right and left, and a horizontal relative movement of the tufting unit 30 relative to the frame 20 is generated exclusively by the components described below.

[0060] In the embodiment shown, the tufting unit 30 has a total of 88 tufting needles 31. However, it should be understood that more or fewer tufting needles 31 can also be used.

[0061] Fig. 3 shows an inner frame 50, which is located laterally to the tufting unit 30. Such an inner frame 50 is located, in particular, behind each of the two in Fig. 2 visible tufted rails 42, i.e. behind the paper plane of Fig. 2 Tufted rails 42 are also in Fig. 3 as can be seen, with one located on the left side and one on the right side of the inner frame 50. Each inner frame 50 thus has two tufting rails 42; when using two inner frames 50 (one on the left and one on the right side of the tufting machine 10), there are a total of four tufting rails 42 (two each, viewed in the direction of travel, on the front and rear of the inner frames 50).

[0062] The inner frame 50 has a receptacle 32 for a hydraulic cylinder, by means of which the inner frame 50 can be raised or lowered. This movement is transmitted to the tufting unit 30 in a manner to be described later. This results in the insertion movement already described, using the tufting needles 31. This movement is guided in one dimension by means of the tufting rails 42.

[0063] Four horizontal hydraulic cylinders 52 are attached to the inner frame 50. These cylinders are designed to trigger a horizontal movement of the tufting unit 30 relative to the inner frame 50. The horizontal hydraulic cylinders 52 are directly attached to the inner frame 50, and their respective pistons 53 are attached to the tufting unit 30 in a manner to be described later. The horizontal hydraulic cylinders are thus able to actively move the tufting unit 30 within the frame 20 between two predetermined horizontal end positions.

[0064] The horizontal movement is stabilized by guide rails 44. These are arranged horizontally in the inner frame 50 and guide the movement, initiated by the hydraulic cylinders 52, in one dimension. For this purpose, linear bearings, which are attached to the tufting unit 30, engage in the guide rails 44. This will be described in more detail below.

[0065] The tufting unit 30 also includes a rotary encoder 34, which serves to determine the current horizontal position of the tufting unit 30 relative to the frame 20. The rotary encoder 34 can monitor the horizontal movement and be used to control it.

[0066] The in Fig. 3 The components shown are to be considered as a single unit. During operation of the tufting machine 10, this unit is moved up and down by means of the hydraulic cylinders (not shown) to initiate the tufting motion. Thus, the components responsible for the horizontal movement are also moved up and down.

[0067] Fig. 4 shows a cross-sectional view along the in Fig. 3 Section line marked with AA. This view is therefore of Fig. 4 to show a side view in the longitudinal direction. The components already mentioned can be seen. In particular, two hydraulic cylinders 52 can be seen in a frontal top view, exerting a force transverse to the plane of the paper. Fig. 4 can exercise this. Accordingly, the direction of movement is also intended to be perpendicular to the plane of the paper. Fig. 4 lies.

[0068] The stabilization of the horizontal movement in the longitudinal direction is achieved via the aforementioned guide rails 44. These are in Fig. 4 its cross-section can be seen. The vertical movement for tufting is achieved by a hydraulic cylinder (not shown) acting on the mounting 32, which moves the inner frame 50 up and down. This movement is transmitted to the tufting unit 30 via the guide rails 44 in a manner to be described later.

[0069] Fig. 5 Figure 3 shows the tufting unit 30 and other components in a side view. It can be seen that the tufting needles 31 of the tufting unit 30 point downwards and can therefore be inserted into a substrate 12 shown here by a vertical movement. In doing so, they typically pick up cut yarn sections.

[0070] Linear bearings 46 are mounted on the tufting unit 30. The linear bearings 46 engage in the guide rails 44. The linear bearings 46 thus enable a horizontal relative movement of the tufting unit 30 relative to the inner frame 50. The previously described vertical movement of the inner frame 50 is transmitted to the tufting unit 30 by the combination of guide rails 44 and linear bearings 46, which therefore also performs the movement.

[0071] The horizontal hydraulic cylinders 52 and their respective pistons 53 are mounted on respective cylinder mounts 48. In this case, the cylinder mounts 48 are each arranged directly on a linear bearing 46, specifically above and below, respectively, as shown in Fig. 5 This can be seen. This allows for an advantageously simple movement. Furthermore, forces are introduced directly at the linear bearings 46, thus preventing tilting.

[0072] The described implementation enables the frame 20 to travel at a constant speed over the surface 12, a movement achieved by the drive unit 21. The horizontal relative movement of the tufting unit 30 relative to the frame 20, actively controlled by the horizontal hydraulic cylinders 52, makes it possible to temporarily move the tufting unit 30 against the direction of travel during the continuous movement of the frame 20. This movement relative to the frame 20 can be set to such a speed that the tufting unit 30 does not perform any horizontal relative movement to the surface 12 for a certain period, for example, approximately 2 seconds. The tufting unit 30 thus remains in a constant position on the surface 12 and can carry out the tufting process, i.e., the vertical movement already described, without any interruption and without requiring the frame 20 to stop.

[0073] To monitor the relative motion, in Fig. 5 A rack 36 is shown, which interacts with the previously mentioned rotary encoder 34. This allows immediate feedback on the current relative position between the tufting unit 30 and the frame 20 at any time. This can be used to control the movement. The rack 36 and rotary encoder 34 thus together form a position detection unit 33, as shown in Fig. 6 can be seen.

[0074] Fig. 6 shows a tufting unit 30 with more components than Fig. 3 In particular, the interaction of the horizontal hydraulic cylinders 52 with the linear bearings 46 and the cylinder mounts 48 is clearly visible. The horizontal hydraulic cylinders 52 provide the previously described horizontal relative movement, while the mount 32 serves to attach a hydraulic cylinder that provides vertical movement.

[0075] Horizontal hydraulic cylinders 52, cylinder mounts 48, linear bearings 46 and guide rails 44 together form a horizontal motion unit 40, which enables a horizontal movement of the tuft unit 30 relative to the frame 20.

[0076] Furthermore, in Fig. 6 A yarn feeder 38 is shown, which serves to feed a yarn to a tufting needle 31. Bezugszeichenliste

[0077] 10 Tufting machine 12 Substrate 20 Frame 21 Drive unit 22 Tracked chassis 24 Measuring wheel 25 Door 26 Smoothing wheel 30 Tufting unit 31 Tufting needles 32 Mount 33 Position detection unit 34 Rotary encoder 36 Rack and pinion 38 Yarn feeder 40 Horizontal movement unit 42 Tufting rails 44 Guide rails 46 Linear bearings 48 Cylinder mount 50 Inner frame 52 Horizontal hydraulic cylinders 53 Piston

Claims

1. Tufting machine, comprising ▪ a frame (20), ▪ a drive unit (21) which is designed to move the frame (20) on a base (12) at least in a forward direction, and ▪ a tufting unit (30) which is designed to insert a number of yarn strands into the substrate (12) during a respective tufting operation, characterized in that the tufting machine has a horizontal movement unit (40) which is designed to move the tufting unit (30) relative to the frame (20) during a tufting operation at least counter to the forward direction.

2. Tufting machine according to claim 1, characterized in that the horizontal movement unit (40) is designed to move the tufting unit (30) relative to the frame (20) against the forward direction during a tufting operation at the same speed as the drive unit (21) moves the frame (20) on the base (12) in the forward direction.

3. Tufting machine according to one of the preceding claims, characterized in that the horizontal movement unit (40) is designed to hold the tufting unit (30) in one position on the substrate (12) during a tufting operation, while the drive unit (21) moves the frame (20) away.

4. Tufting machine according to one of the preceding claims, characterized in that the horizontal movement unit (40) is designed to move the tufting unit (30) in the forward direction relative to the frame (20) between two immediately successive tufting operations.

5. Tufting machine according to one of the preceding claims, characterized in that the horizontal movement unit (40) is designed to move the tufting unit (30) relative to the frame (20) from a starting position to an end position during a tufting operation, and to move it from the end position to the starting position between two immediately successive tufting operations.

6. Tufting machine according to one of the preceding claims, characterized in that the horizontal movement unit (40) is designed to move the tufting unit (30) linearly relative to the frame (20), the tufting machine (10) having a number of guide rails (44) for linear guidance of the tufting unit (30) in and against the forward direction.

7. Tufting machine according to claim 6, characterized in that a number of linear bearings (46) are provided on a first side and on a second side of the tufting unit (30), each linear bearing (46) engaging in one of the guide rails (44).

8. Tufting machine according to claim 6 or 7, characterized by an inner frame (50) which is arranged inside the frame (20) and is vertically movable relative to the frame (20), wherein the guide rails (44) are fixed to the inner frame (50).

9. Tufting machine according to claim 8, characterized by one or more vertical drives which are designed to move the inner frame (50) vertically relative to the frame in order to carry out a tufting operation, one or more tufting rails (42) being provided which keep the inner frame (50) vertically movable relative to the frame (20).

10. Tufting machine according to one of the preceding claims, characterized in that the horizontal movement unit (40) comprises a number of horizontal hydraulic cylinders (52), a spindle drive, a linear drive and / or an electric servomotor for moving the tufting unit (30) horizontally relative to the frame (20).

11. Tufting machine according to one of the preceding claims, characterized by a position determining unit (33) for determining the position of the tufting unit (30) relative to the frame (20).

12. Tufting machine according to one of the preceding claims, characterized by a measuring wheel (24) for detecting a movement of the frame (20) on the substrate (12).

13. Tufting machine according to one of the preceding claims, characterized by a control device which controls the horizontal movement unit (40) as a function of a movement of the frame (20) on the substrate (12).

14. A method of inserting yarn strands into a substrate, the method comprising the following steps repeated a plurality of times: ▪ Insertion of the yarn strands by means of a tufting unit, which is mounted in a frame, characterized by ▪ Moving the frame in a forward direction and moving the tufting unit relative to the frame and at least against the forward direction such that the tufting unit remains in the same position on the substrate, then ▪ Further movement of the frame on the base, moving the tufting unit relative to the frame to a starting position for the next insertion of the yarn strands.

15. The method according to claim 14, which is carried out with a tufting machine according to any one of claims 1 to 13.