Cutter for self-adhesive, unsupported endless belt labels

Abstract

The invention relates to a cutter for self-adhesive, backingless continuous tape labels, comprising a transport roller rotatable about a pivot axis and a cutter unit. The cutter unit includes a cutter carriage linearly movable parallel to the pivot axis of the transport roller and a cutting blade fixed to the cutter carriage and directed towards the transport roller. The continuous tape labels can be guided between the transport roller and the cutter unit. The cutter unit comprises a cutter holder which forms a single assembly with the cutting blade, the cutting blade projecting beyond the cutter holder with a fixed overhang. The assembly is slidably attached to the cutter carriage and includes a spring device, in particular a compression spring, which biases the assembly into an extended position.

Description

[0001] The invention relates to a cutter (also referred to as a cutter) for self-adhesive, backingless continuous tape labels, comprising a transport roller rotatable about a pivot axis and a cutting unit comprising a cutting carriage linearly movable parallel to the pivot axis of the transport roller and a cutting blade fixed to the cutting carriage and directed towards the transport roller, wherein the continuous tape labels can be guided between the transport roller and the cutting unit. Such a cutter is known from document DE 199 58 274 A1.

[0002] To process such linerless labels, which are coated on one side with adhesive, a cutter or a label printer with a cutter is required to separate the labels from the continuous tape. For this purpose, the cutter's transport roller, which acts as a counter-holder for the cutting blade, is coated with an elastomeric material, as described in document DE 199 58 274 A1. This material allows the cutting blade to penetrate the coating when separating the labels.

[0003] A disadvantage of this method is that the cutting blade gradually damages the elastomeric coating, causing wear on the transport roller. This is particularly problematic because the labels rest on the transport roller with their adhesive-coated side facing down. For trouble-free transport of the continuous tape labels, it is essential that the surface of the transport roller offers little to no adhesion to the adhesive. This property of the transport roller, especially one with a non-stick coating, is lost over time due to wear caused by the cutting blade penetrating the surface.

[0004] The invention is based on the objective of providing a cutter of the type mentioned above which also enables trouble-free transport of the continuous tape labels over the long term.

[0005] This problem is solved by a cutter with the features of independent claim 1, and in particular by the fact that the knife unit comprises a knife holder which forms a unit with the cutting knife in which the cutting knife projects with a fixed overhang beyond the knife holder, wherein the unit is slidably attached to the knife slide and a spring device, in particular a compression spring, is provided which biases the unit into an extended position.

[0006] The cutter according to the invention has the advantage that the cutting blade does not penetrate the transport roller, or at least not as deeply, when separating the labels. This is because, due to its spring-loaded, movable mounting, the cutting blade can deflect away from the surface of the transport roller upon contact. Nevertheless, the spring force exerts sufficient pressure on the cutting blade to achieve a clean cut when separating a label. Because the cutting blade moves together with the cutter unit and always has the same fixed protrusion, it can be ensured that the penetration depth of the cutting blade into the continuous tape labels remains constant and that the labels can be reliably separated even in the case of tolerance-related unevenness in the surface of the transport roller.

[0007] It is preferably provided that the knife holder and the cutting blade are each designed in a plate-like shape, with their flat sides abutting each other. A plate-like component is both lightweight and stable. Two plate-like components abutting each other reinforce each other.

[0008] Furthermore, it is preferable for the cutting blade to be positioned between the blade carriage and the blade holder. Between the blade holder and the blade carriage, the cutting blade can be supported on both sides and thus held particularly securely.

[0009] The knife carriage can have a base body and a, in particular plate-shaped, extension projecting from the base body towards the transport roller, to which the assembly is slidably attached, wherein preferably the flat sides of the plate-shaped extension are oriented parallel to the plane of movement of the cutting knife when the knife carriage is moved and / or parallel to the plane of movement of the cutting knife when the assembly is moved. This increases the stability of the arrangement.

[0010] Preferably, the spring assembly is supported on one side by the knife slide, in particular the aforementioned base body, and on the other side by the assembly unit. Alternatively or additionally, it is preferred if the spring assembly directly acts on both the knife holder and the cutting knife. This allows for a compact design of the arrangement.

[0011] According to one embodiment of the invention, the knife unit comprises a fastening screw with which the assembly is slidably attached to the knife carriage, wherein, in the axial direction of the fastening screw, the assembly is accommodated with play between the head of the fastening screw and the knife carriage. The fastening screw allows for secure attachment in a simple manner. To nevertheless ensure its slidability, the assembly is accommodated with play between the head of the fastening screw and the knife carriage.

[0012] To allow play in the assembly between the head of the fastening screw and the knife slide, the knife assembly preferably includes a spacer sleeve that extends at least through the assembly, wherein the shank of the fastening screw extends at least into the spacer sleeve, and wherein the head of the fastening screw abuts an axial end of the spacer sleeve to allow the play.

[0013] It can be provided that the spacer sleeve abuts with its other axial end on a side of the knife slide facing the assembly, in particular the aforementioned extension, and that the shank of the fastening screw extends through the spacer sleeve into the knife slide, in particular the extension, wherein the fastening screw is screwed into the knife slide, in particular the extension, and wherein in the axial direction the extension of the spacer sleeve is greater than the extension of the assembly.

[0014] Alternatively, it can be provided that the spacer sleeve extends through the assembly and the knife slide, in particular the aforementioned extension, and abuts a flange formed at its other axial end on a side of the knife slide, in particular the extension, facing away from the assembly, wherein the fastening screw is screwed into the spacer sleeve, and wherein in the axial direction the extension of the spacer sleeve is greater than the common extension of the assembly and the knife slide, in particular the extension.

[0015] Preferably, at least one elongated hole is formed in the knife holder through which the fastening screw, and in particular the aforementioned spacer sleeve, extends, and the assembly is displaceable in the direction of the elongated hole. The cutting blade can then be arranged in a region of the knife holder that is not in direct contact with the fastening screw. However, the displaceability of the assembly can also be achieved in other ways, for example, if the cutting blade is arranged on the side of the knife holder facing away from the knife slide. The head of the fastening screw can then be captured and displaceably guided in a linear guide formed on the knife holder with stops on both sides.In particular, both the knife holder and the cutting blade each have a slotted hole that is aligned with each other and through which the fastening screw, and especially the aforementioned spacer sleeve, extends, allowing the assembly to be displaced in the direction of the two slots. This is particularly advantageous if the dimensions of the knife holder and the cutting blade are at least approximately the same, as is preferred for a stable and compact design of the assembly.

[0016] According to a further embodiment of the invention, the knife holder and the cutting blade are joined together to form the assembly, wherein the knife holder has at least one pin projecting towards the cutting blade and the cutting blade has at least one opening to receive the respective pin. This allows a stable assembly to be realized in a simple manner.

[0017] It is preferred if the knife holder has two pins and the cutting blade has two openings that are opposite each other with respect to the fastening screw. The resulting symmetrical design creates a particularly stable assembly.

[0018] It is further preferred if the respective pin of the knife holder extends through the respective opening of the cutting knife and into a respective elongated hole formed in the knife slide. This simultaneously ensures that the respective pin prevents the assembly from rotating relative to the knife slide. However, it is also possible to provide a separate anti-rotation device, for example, two retaining arms projecting from the knife holder towards the knife slide, which bear against the knife slide on both sides, in particular the aforementioned extension.

[0019] The projection of the cutting blade beyond the blade holder can be between 0.1 mm and 0.8 mm, preferably between 0.2 mm and 0.3 mm. This ensures that the cutting blade protrudes only slightly, yet sufficiently, beyond the blade holder to reliably separate the labels.

[0020] According to a further embodiment of the invention, a threaded spindle with a threaded rod and the knife slide as a spindle nut, as well as an electric motor driving the threaded rod, are provided to move the knife slide linearly. This enables precise movement of the knife slide in a simple manner. Preferably, a linear guide in the form of a guide rod running parallel to the threaded rod is provided, which extends through an opening formed in the knife slide and along which the knife slide is guided for linear movement. This allows the knife slide to be held particularly stable during movement.

[0021] The knife carriage can be moved back and forth between a first end position and a second end position, with the cutting blade having a cutting edge on the leading edge in both directions of travel. This allows one label to be cut off during the forward movement and the next label during the return movement of the knife carriage. Therefore, after cutting off a label, the knife carriage does not need to be returned to the first end position before the next label can be cut off, thus increasing throughput. Preferably, in the plane of movement of the cutting blade, the two cutting edges together form a V-shape during the movement of the knife carriage. This allows for particularly clean cuts when separating the labels, as both cutting edges also exert a force component during the cutting process, pressing down on the continuous tape labels.

[0022] In particular, the cutter carriage is linearly movable transversely, especially vertically, to a transport direction of the self-adhesive, backingless continuous tape labels, and / or the assembly is linearly displaceable from the cutter carriage. Specifically, the cutting blade projects with its fixed overhang beyond an end face of the blade holder that faces the transport roller. The transport roller can be provided with a non-stick coating or made of a non-stick material. Preferably, the transport roller is a driven transport roller, so that the continuous tape labels are also pulled and held under tension in the area of ​​the cutter. However, controlled transport of the continuous tape labels is generally ensured by a pressure roller of a label printer, driven by an electric motor, in which the cutter is integrated.In principle, the transport roller can also be a non-driven, rotating transport roller.

[0023] The present invention further relates to a label printer with a cutter for self-adhesive, carrierless continuous tape labels, as described above.

[0024] The present invention also relates to a scale, in particular a retail scale, with a label printer as described above.

[0025] Further advantageous embodiments of the invention are described in the dependent claims, the description of the figures and the drawing.

[0026] The invention is described below by way of example with reference to the drawing. The drawing shows, Fig. 1 a scale according to the invention, in particular a retail scale, with a label printer according to the invention, Fig. 2A, B the label printer made of Fig. 1 In a single view with a front cover and in a view in which the front cover is omitted so that a cutter according to the invention is visible, Fig. 3 the cutter made of Fig. 2B in individual view with a knife unit, Fig. 4A, B the knife unit made of Fig. 3 in a single view with a component comprising a knife holder and a cutting knife in a front view and in a view in which the knife holder is hidden, Fig. 5A, B the knife unit made of Fig. 4A in a side view and in an exploded view, Fig. 6A, B the knife unit made of Fig. 4A in a rear view and in a representation in which the assembly is removed, Fig. 7 the assembly made of Fig. 6B in an exploded view, Fig. 8A, B the knife unit according to Fig. 4A In a representation with the assembly extended and in a representation with the assembly retracted, Fig. 9 the knife unit according to the Fig. 8A und 8B in a target position, Fig. 10 a method for separating continuous tape labels, and Fig. 11 an alternative knife unit in a cut side view.

[0027] The in Fig. 1 The illustrated, exemplary retail scale 11 comprises a load platform 13, which determines the weight of an item placed on it. This weight is displayed on a screen 15 for the customer and on a screen 17 for the salesperson. The screen 17 is a touchscreen, allowing the retail scale 11 to be operated via this device. An identification number (PLU) assigned to the respective item can be entered via the touchscreen 17. Using the weight, a price for the item can then be calculated and displayed on both screens 15 and 17. Furthermore, the retail scale includes a label printer 19 for printing a label with the weight, the name of the item, and the calculated price. Fig. 1 A schematic representation of a control device 20 of the retail scale 11 is shown, which is integrated into the retail scale 11 and is designed to control the operation of the retail scale 11, in particular including the label printer 19.

[0028] The label printer 19 is in Fig. 2A shown in a single view from the front. Fig. 2B The front cover of the label printer 19, in the form of a flap 21 and a separate cover section 22, has been omitted, so that the interior of the label printer 19 is visible. Inside the label printer 19, a receptacle 23 for a label roll and a deflection roller 25 are visible. A printhead and a print roller of the label printer 19, however, are in Fig. 2B not visible.

[0029] The label printer 19 can be operated in particular with self-adhesive, linerless continuous tape labels. Therefore, the label printer 19 has a cutter 27 (which is located in Fig. 2B (partially concealed by a cover plate 28), with which the labels are separated from the continuous tape. As can be seen from Fig. 3 The cutter 27 comprises a driven transport roller 29, rotatable about a pivot axis, for the continuous tape labels. In addition, a knife unit 31 is provided, which includes a knife carriage 33 (see figure). Fig. 4A bis 6B The label printer 19 comprises a linearly movable transport roller 29 parallel to its axis of rotation, and a plate-shaped cutting blade 34, fixed to rotation on the knife carriage 33 and directed towards the transport roller 29. The label printer 19 can also be operated with receipt paper.

[0030] The cutter slide 33 is designed as a spindle nut with a through-hole 35 with an internal thread, which is driven by an electric motor 39 in both axial directions of the threaded rod 37 via a threaded rod 37, with which it forms a threaded spindle. To ensure stable guidance of the cutter slide 33 during its movement, the cutter 27 further comprises a linear guide running parallel to the threaded rod 37, which is designed as a guide bar 41 with a round cross-section extending through an opening 43 formed in the cutter slide 33. The opening 43 has an elongated cross-section so that tolerances in the distance between the threaded rod 37 and the guide bar 41 can be compensated for.

[0031] The self-adhesive, carrierless continuous tape labels are guided between the transport roller 29 and the cutting unit 31, with the adhesive-coated side of the continuous tape labels facing the transport roller 29, which acts as a counter-holder for the cutting unit 31, in particular the cutting blade 34 of the cutting unit 31. The two opposing directions of travel of the blade carriage 33 are perpendicular to the transport direction of the continuous tape labels. The print head and the printing roller are located in the Fig. 2B and 3 arranged behind or under the transport roller 29 and therefore - as already mentioned above - not visible in the figures.

[0032] The knife carriage 33 has a base body 45 and a plate-shaped extension 47 projecting from the base body 45 towards the transport roller 29. The cutting knife 34 is held on this extension by means of a plate-shaped knife holder 49 of the knife unit 31. The cutting knife 34 is positioned between the extension 47 and the knife holder 49. The extension 47, the cutting knife 34, and the knife holder 49 are arranged with their flat sides abutting each other. The flat sides of these components are thus oriented parallel to the plane of movement of the cutting knife 34 during the movement of the knife carriage 33. The passage 35 for the threaded rod 37 and the opening 43 for the guide rod 41 are each provided in the base body 45.

[0033] The knife holder 49 and the cutting knife 34 form a unit 51 (see the Fig. 5A, 5B , 6B and 7), which is slidably attached to the extension 47 of the knife slide 33 (see the respective double arrow in the Fig. 5A and 8A ), which are moved into an extended position by a spring device 53 in the form of a compression spring (cf. Fig. 8A ) is pressed and the endless tape labels 55 running between the transport roller 29 and the knife unit 31 are pushed back into a retracted position against the spring force of the spring device 53 when the knife unit 31 is placed on top of it (see Fig. 8B The spring assembly 53 is supported at one end on the base body 45 and at the other end on the assembly 51, specifically on both the knife holder 49 and the cutting knife 34.

[0034] The spring-loaded mounting of the cutting blade 34 or the assembly 51 has the advantage that the cutting blade 34, or at least its tip, does not penetrate the surface of the transport roller 29 when a label is cut off. Instead, it is retracted by a distance determined by the spacing between the blade unit 31 and the transport roller 29 relative to its extended position. This prevents the surface of the transport roller 29 from becoming roughened by continuous cutting. Such a roughened surface would cause the continuous tape labels to adhere more strongly to the transport roller 29 over time, with their adhesive-coated side sticking to it, thus disrupting the smooth transport of the continuous tape labels.

[0035] As can be seen in particular from Fig. 4A (and also from the Fig. 5A , 6A and 8AThe cutting blade 34 protrudes with a defined projection d beyond the blade holder 49, in particular an end surface 56 of the blade holder 49 facing the transport roller 29. The penetration depth of the cutting blade 34 into the continuous tape labels thus remains constant. This also applies in the case of tolerance-related unevenness in the surface of the transport roller 29. The projection d is adapted to the thickness of the labels and selected such that the labels can be reliably separated from the continuous tape. For example, the projection can have a value between 0.1 mm and 0.8 mm, preferably between 0.2 mm and 0.3 mm.

[0036] The knife unit 31 is preferably oriented such that the cutting knife 34, or the tip of the cutting knife 34, runs along the generatrix of the transport roller 29 closest to the cutting knife 34, or the tip of the cutting knife 34, when the knife carriage 33 is moved. However, it is also possible for the cutting knife 34, or the tip of the cutting knife 34, to run along a generatrix of the transport roller 29 that has a predetermined offset from the nearest generatrix.

[0037] The sliding mounting of the assembly 51, comprising the knife holder 49 and the cutting knife 34, is ensured by an arrangement of elongated holes. For this purpose, an elongated hole 57, 59 is formed in both the knife holder 49 and the cutting knife 34, respectively. These elongated holes are aligned with each other, and a fastening screw 61 extends through them, allowing the assembly 51 to be slidably mounted along the two elongated holes 57, 59. The fastening screw 61 is screwed into a mounting hole 63 formed in the extension 47 of the knife carriage 33.

[0038] To prevent the assembly 51 from being rigidly fixed to the extension 47, the assembly 51 is mounted with play in the axial direction of the fastening screw 61 between the head of the fastening screw 61 and the extension 47. This play is achieved by providing a spacer sleeve 65, the axial extent of which is greater than the corresponding extent of the assembly 51, and through which the shank of the fastening screw 61 is inserted, so that the spacer sleeve 65 also extends through the two elongated holes 57, 59. The head of the fastening screw 61 abuts the spacer sleeve 65 at one axial end, and the extension 47 of the knife slide 33 abuts the spacer sleeve 65 at the other axial end.

[0039] The blade holder 49 and the cutting blade 34 are assembled to form the assembly 51. For this purpose, the blade holder 49 has two pins 67 projecting towards the cutting blade 34, which engage in corresponding openings 69 formed in the cutting blade 34. These two connections are opposite each other with respect to the fastening screw 61 and the spacer sleeve 65, respectively. The two pins 67 of the blade holder 49 extend through the two openings 69 formed in the cutting blade 34 and each engage in a corresponding elongated hole 71 formed in the extension 47. This reliably prevents the assembly 51 from rotating about the longitudinal axis of the fastening screw 61 or the spacer sleeve 65.

[0040] The knife carriage 33 is located between a first end position to the right of the transport roller 29 (cf. Fig. 8A The cutting blade 34 can be moved back and forth between the transport roller 29 (not shown) and an analogous second end position to the left of the transport roller 29 (not shown), and can cut labels in both directions of travel. For this purpose, the cutting blade 34 has a cutting edge 73 on the leading edge in both directions of travel of the blade carriage 33. The two cutting edges 73 together form a V-shape in the plane of movement of the cutting blade 34 when the blade carriage 33 is moved, which allows for a particularly good cutting result. Before a change of travel direction, the continuous tape labels 55 are advanced stepwise by motor, one label at a time.

[0041] An alternative method for separating the continuous tape labels 55 is described in Fig. 9 As shown, in the alternative method, a label is first printed, then the continuous tape labels are advanced by one label, and subsequently the knife unit 31 or the knife carriage 33 is moved between a starting position that corresponds to the aforementioned first end position of the knife carriage 33 (see figure). Fig. 8A ), and a target position as described in Fig. 9 The process is linear, as shown. Fig. 9 This results in the cutting blade 34 being located to the left of the left edge of the continuous tape labels 55, i.e., the label to be detached has been completely detached. However, the detached label is in the target position according to Fig. 9 held by the knife unit 31 on the transport roller 29, it can then be removed by an operator.

[0042] Holding the detached label in the target position of the cutting unit 31 is achieved by the continuous tape labels 55 resting with their underside on the transport roller 29 and being clamped between the end surface 56 of the knife holder 49, which rests on the top of the continuous tape labels 55 and rests on the transport roller 29, as the cutting unit 31 moves from the starting position to the target position. This clamping action applies particularly to the detached label in the target position of the cutting unit 31. Ultimately, the cutting unit 31, or rather the knife carriage 33, is not moved completely into the aforementioned second end position, but only to the point where the end surface 56 of the knife holder 49, with a trailing section, remains within the area of ​​the continuous tape labels 55 or the detached label.In the process of the knife unit 31, the cutting knife 34 sits sliding on the surface of the transport roller 29.

[0043] It is advantageous if, during the operation of the knife unit 31, the end surface 56 of the knife holder 49 runs along the generatrix of the transport roller 29 that is closest to the end surface 56 of the knife holder 49, as this ensures particularly good retention of the detached label. The cutting knife 34, or rather the tip of the cutting knife 34, then runs along a generatrix of the transport roller 29 that is offset, in particular slightly, from this.

[0044] The system then waits until the detached label is removed by an operator. A detector (not shown) is provided for this purpose, which detects whether the detached label has been removed by an operator. Only then does the cutting unit 31 automatically move out of the target position. The cutting unit 31 can either return to the starting position or move to a further starting position beyond the target position, corresponding to the aforementioned second end position. The continuous tape labels 55 can then be retracted (reversed) to the respective label beginning where the label was detached, before the next label, which has already partially passed through the printing area, is printed. The process steps described above are then repeated for the next label to be detached.

[0045] If the cutting unit 31 has moved further into the next starting position, the cutting unit 31 moves in the opposite direction of travel, i.e., in the direction of the starting position, to a further target position (not shown) to detach the next label. Fig. 9 The position shown corresponds to this, but at the right edge of the continuous tape labels 55. The knife unit 31 is therefore not returned completely to the first end position, but only to the point where the end surface 56 of the knife holder 49, with a trailing section, remains within the area of ​​the continuous tape labels 55, so that the next detached label is also held on the transport roller 29. After the next label has been removed, the knife unit 31 then returns completely to the starting position.

[0046] To calibrate the starting position of the cutting unit 31, a reference run of the cutting unit 31 is performed when the label printer 19 is switched on. For this purpose, the cutting unit 31 is equipped with a magnet 75, which interacts with a stationary magnetic field sensor 77, in particular a Hall sensor, which detects the passing magnet 75 (see figure). Fig. 3 ).

[0047] A flowchart illustrating the process steps described above is shown in Fig. 10 The process steps are shown, with the control unit 20 controlling or executing them. The alternative method can also be carried out with carrier tape labels, where the labels are applied to a carrier tape.

[0048] In Fig. 11 An alternative knife unit 31 to the one described in the previous figures is shown. Unlike the previous knife unit 31, the knife unit 31 extends according to Fig. 11 The spacer sleeve 65 extends not only through the assembly 51, but also through the extension 47 of the knife slide 33. In particular, the spacer sleeve 65 is positioned against the knife unit 31 according to Fig. 11 with the other axial end not on the side of the extension 47 facing the assembly 51, but with a flange 79 formed at this end on the opposite side of the extension 47. Furthermore, the fastening screw 61 of the knife unit is according to Fig. 11 not screwed into the extension 47, but into the spacer sleeve 65. In order to allow the aforementioned play of the assembly 51, the extension of the spacer sleeve 65 in the axial direction of the fastening screw 61 is greater than the combined extension of the assembly 51 and extension 47 of the knife slide 33.

[0049] The alternative knife unit 31 according to Fig. 11 This has the advantage that no mounting hole with an internal thread is required in the extension 47. This is particularly advantageous if the knife carriage 33 with the extension 47 is made of plastic. For the same reason, the knife unit 31 is designed according to... Fig. 11 An insert sleeve 81 is also provided in passage 35. The spacer sleeve 65 and the insert sleeve 81 can be made of a metal that can easily be provided with an internal thread for the fastening screw 61 or for the threaded rod 37. Furthermore, the alternative knife unit 31 is designed according to... Fig. 11 The two elongated holes 71 are designed as countersunk holes, but can just as well be designed as through elongated holes. Bezugszeichenliste

[0050] 11 Store scale 13 Load plate 15 Customer display 17 Operator touchscreen 19 Label printer 20 Control unit 21 Flap 22 Cover section 23 Mount 25 Deflection roller 27 Cutter 28 Cover plate 29 Transport roller 31 Knife unit 33 Knife carriage 34 Cutting blade 35 Through hole 37 Threaded rod 39 Electric motor 41 Guide rod 43 Through hole 45 Base body 47 Extension 49 Blade holder 51 Assembly unit 53 Spring device 55 Endless tape labels 56 End face 57 Slotted hole 59 Slotted hole 61 Mounting screw 63 Mounting hole 65 Spacer sleeve 67 Pin 69 Opening 71 Slotted hole 73 Cutting edge 75 Magnet 77 Magnetic field sensor 79 Flange 81 Insert sleeve d protrusion

Claims

1. Cutter for self-adhesive, carrier-free endless band labels (55), with a transport roller (29) rotatable about a rotational axis and a knife unit (31) which comprises a knife carriage (33) which is linearly movable parallel to the rotational axis of the transport roller (29) and a cutting knife (34) which is held in a rotationally fixed manner on the knife carriage (33) and directed towards the transport roller (29), wherein the endless band labels (55) can be guided between the transport roller (29) and the knife unit (31), characterized by that the knife unit (31) comprises a knife holder (49) which forms a structural unit (51) with the cutting knife (34), in which the cutting knife (34) projects beyond the knife holder (49) by a fixed projection (d), wherein the structural unit (51) is displaceably fastened to the knife carriage (33) and a spring device (53), in particular a compression spring, is provided which prestresses the structural unit (51) into an extended position.

2. Cutter according to claim 1, characterized by that the knife holder (49) and the cutting knife (34) are each plate-shaped, wherein the knife holder (49) and the cutting knife (34) lie against one another with their flat sides, and / or that the cutting knife (34) is arranged between the knife carriage (33) and the knife holder (49).

3. Cutter according to claim 1 or 2, characterized by that the knife carriage (33) has a base body (45) and a particularly plate-shaped extension (47) which projects from the base body (45) in the direction of the transport roller (29) and to which the structural unit (51) is displaceably fastened, wherein the flat sides of the plate-shaped extension (47) are preferably oriented parallel to the plane of movement of the cutting knife (34) when the knife carriage (33) is moved and / or parallel to the plane of movement of the cutting knife (34) when the structural unit (51) is displaced.

4. Cutter according to one of the preceding claims, characterized by that the spring device (53) is supported on the one hand on the knife carriage (33), in particular a base body (45) thereof, and on the other hand on the structural unit (51), and / or that the spring device (53) directly acts on both the knife holder (49) and the cutting knife (34).

5. Cutter according to one of the preceding claims, characterized by that the knife unit (31) comprises a fastening screw (61) with which the structural unit (51) is slidably fastened to the knife carriage (33), wherein in the axial direction of the fastening screw (61) the structural unit (51) is received with play between the head of the fastening screw (61) and the knife carriage (33).

6. Cutter according to claim 5, characterized by thatthe blade unit (31) comprises a spacer sleeve (65) which extends at least through the structural unit (51), wherein the shank of the fastening screw (61) extends at least into the spacer sleeve (65), and wherein the head of the fastening screw (61) bears against an axial end of the spacer sleeve (65) in order to allow for play.

7. Cutter according to claim 6, characterized by thatthe spacer sleeve (65) rests with its other axial end on a side of the knife carriage (33), in particular an extension (47) thereof, facing the structural unit (51), and the shaft of the fastening screw (61) extends through the spacer sleeve (65) into the knife carriage (33), in particular the extension (47), wherein the fastening screw (61) is screwed into the knife carriage (33), in particular the extension (47), and wherein the extension of the spacer sleeve (65) is greater in the axial direction than the extension of the structural unit (51).

8. Cutter according to claim 6, characterized by thatthe spacer sleeve (65) extends through the structural unit (51) and the knife carriage (33), in particular an extension (47) thereof, and rests with a flange (79) formed at its other axial end on a side of the knife carriage (33), in particular the extension (47), facing away from the structural unit (51), wherein the fastening screw (61) is screwed into the spacer sleeve (65), and wherein in the axial direction the extension of the spacer sleeve (65) is greater than the common extension of the structural unit (51) and the knife carriage (33), in particular the extension (47).

9. Cutter according to one of claims 5 to 8, characterized by thatat least in the knife holder (49) an elongated hole (57) is formed through which the fastening screw (61), and in particular the spacer sleeve (65), extends, wherein the structural unit (51) is displaceable in the direction of the elongated hole (57), wherein preferably both in the knife holder (49) and in the cutting knife (34) an elongated hole (57, 59) is formed which are matched to one another and through which the fastening screw (61), and in particular the spacer sleeve (65), extends, wherein the structural unit (51) is displaceable in the direction of the two elongated holes (57, 59).

10. Cutter according to one of the preceding claims, characterized by thatthe knife holder (49) and the cutting knife (34) are plugged together to form the structural unit (51), wherein for this purpose the knife holder (49) has at least one pin (67) projecting in the direction of the cutting knife (34) and the cutting knife (34) has at least one opening (69) receiving the respective pin (67).

11. Cutter according to one of claims 5 to 9 and claim 10, characterized by that the knife holder (49) has two pins (67) and the cutting knife (34) has two openings (69) which are opposite one another with respect to the fastening screw (61).

12. Cutter according to claim 10 or 11, characterized by that the respective pin (67) of the knife holder (49) extends through the respective opening (69) of the cutting knife (34) and into a respective elongated hole (71) formed in the knife carriage (33).

13. Cutter according to one of the preceding claims, characterized by thatthe projection (d) has a value between 0.1 mm and 0.8 mm, preferably between 0.2 mm and 0.3 mm.

14. Cutter according to one of the preceding claims, characterized by that a threaded spindle with a threaded rod (37) and the knife carriage (33) as a spindle nut and an electric motor (39) driving the threaded rod (37) are provided in order to move the knife carriage (33) linearly, wherein preferably a straight guide running parallel to the threaded rod (37) is provided in the form of a guide rod (41), which extends through an opening (43) formed in the knife carriage (33) and along which the knife carriage (33) is guided so as to be linearly movable.

15. Cutter according to one of the preceding claims, characterized by thatthe knife carriage (33) can be moved back and forth between a first end position and a second end position, wherein the cutting knife (34) has a cutting edge (73) on the respective leading edge in both directions of travel of the knife carriage (33), wherein preferably in the plane of movement of the cutting knife (34) when the knife carriage (33) is moved, the two cutting edges (73) together form a V-shape.

16. Label printer with a cutter (27) for self-adhesive, linerless, endless band labels (55) according to one of the preceding claims.

17. Scales, in particular shop scales, with a label printer (19) according to claim 16.

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