Squeegee rubber, squeegee head and squeegee system

Abstract

The present invention relates first to a squeegee rubber (1) with a squeegee edge (105), comprising in the longitudinal direction of the squeegee rubber (1) on the side opposite the squeegee edge (105) recesses (101) of length b1 and depth t1 for slip-free reception of the squeegee rubber (1) into an engagement device (303) on a squeegee head (3).Furthermore, the present invention relates to a doctor blade head (3) comprising: - at least one bolt (301) having at its first end (301a) an engagement device (303) for receiving a doctor blade rubber (1); - a base body (305) with at least one bolt guide (307), wherein each bolt guide (307) receives and guides the shank (301s) of a bolt (301); - at least one element (309) for receiving at least one spring (311) for generating a contact pressure of the at least one bolt (301), wherein the element (309) is arranged above the bolt guide (307) in the base body (305) and the spring (311) is in operative connection with the second end (301b) of the bolt (301); - at least one device (313) for generating a preload in the spring (311), which is received in a two-part clamping system (315a, 315b). is, wherein the device (313) can be reversibly secured by a terminal block (315b).Finally, a squeegee system (5) is the subject of the present invention.

Description

[0001] The present invention relates to a specially designed squeegee rubber, a squeegee head with this squeegee rubber and a squeegee system having the squeegee head.

[0002] Squeegee systems have long been used in screen printing for printing objects and workpieces using the screen printing process. A squeegee rubber is used to push ink through a screen to apply a design to the object to be printed. In industrial applications, the flexible squeegee rubber is clamped between movable, adjacent holding bars to follow the contours of the surface to be printed and achieve a consistent print result.

[0003] EP 0 099 587 B1 discloses a spring squeegee system designed to achieve flawless printing results even on uneven surfaces. The squeegee rubber is clamped into mounting brackets that are guided in the squeegee head so that they can be moved in the direction of pressure. A spring in each mounting bracket exerts a contact pressure between the squeegee rubber and the screen. This ensures that the pressure on the screen is independent of the elasticity of the squeegee rubber. A further advantage is that narrower squeegee rubbers can be used, which are significantly more flexible than with squeegee rubbers used for pressure transfer. The spring tension of each individual spring can be adjusted using a lock nut.

[0004] The state-of-the-art technical design is primarily used for hard hollow bodies, such as glass. For soft items such as plastic bottles, the state-of-the-art systems are generally not suitable. Therefore, there is a need for innovative solutions.

[0005] For easy cutting of doctor blade belts, WO 2021 / 233591 A1 presents a doctor blade belt with predetermined breaking points perpendicular to the longitudinal propagation direction. DE 203 03 186 U1 describes an ink wiper designed to prevent printing ink from contacting the pins and being transported into the pin guides.

[0006] All of the systems listed above can be easily combined with one another. Nevertheless, the flexibility of the squeegee rubber and the guidance of the squeegee rubber represent a limiting factor in the quality of the print results. In these systems, bolts are guided in a guide block, the preload of which is adjusted using springs and adjusting screws. The preload of each spring in the spring squeegee system is adjusted separately by tightening a lock nut. This is time-consuming. If, despite the greatest care, ink or operating fluids get into the guides of the bolts, the inner coating of the housing, which ensures the sliding properties of the bolt, reacts chemically with the fluids. This results in the entire squeegee head having to be replaced because the guide block is firmly connected to the housing.

[0007] The present invention therefore aims to overcome the disadvantages of the prior art and to provide a flexible squeegee rubber and a squeegee head with optimized squeegee rubber guidance, enabling higher print quality with shorter setup times. Likewise, a novel system is to be provided with which soft and / or flexible bodies can also be printed.

[0008] The above-mentioned object is achieved in a first aspect of the present invention by a squeegee rubber (1) with a squeegee edge (105), comprising recesses (101) of length b1 and depth t1 in the longitudinal direction of the squeegee rubber (1) on the side opposite the squeegee edge (105) for slip-free reception of the squeegee rubber (1) in an engagement device (303) on a squeegee head (3).

[0009] "Squeegee rubber" refers to an element made of a flexible material such as rubber, caoutchouc, silicone, polyurethane, or the like, which has a substantially rectangular cross-section. The thickness of the squeegee rubber (1) is particularly less than its height. A thickness of 4 mm and a height of 5 mm are particularly preferred. The length of the squeegee rubber (1) depends on the intended application and the tool used.

[0010] The "squeegee edge" is the side of the squeegee rubber (1) which is placed on the printing screen, which is located above the body to be printed.

[0011] The "length b1" of the recesses (101) extends in the longitudinal direction of the squeegee rubber (1), the "depth t1" of the recesses (101) extends in the direction of the squeegee edge (105).

[0012] The squeegee rubber (1) according to the invention has the advantage over conventional squeegee rubbers according to the prior art that the recesses (101) can accommodate an engagement device (303) on a squeegee head (3), so that the squeegee rubber (1) is mounted without slippage and cannot shift during use. For this purpose, the recesses (101) can in particular have a length b1 that essentially corresponds to the width of the support surface (301f) of the engagement devices (303). Specifically, the width of the support surface (301f) is reduced by the concave formations (301k) to such an extent that it is the same size as or slightly smaller than the recesses (101) with the length b1 and the depth t1.

[0013] In a further development, the squeegee rubber (1) further comprises grooves (103) of length b2 and depth t2 in the longitudinal direction of the squeegee rubber (1) for increasing the flexibility of the squeegee rubber (1) in the longitudinal direction, which grooves are arranged between the recesses (101).

[0014] The "length b2" of the grooves (103) extends in the longitudinal direction of the squeegee rubber (1), the "depth t2" of the grooves (103) extends in the direction of the squeegee edge (105).

[0015] This refinement results in increased flexibility of the squeegee rubber (1) due to the reduced height of the grooves (103), thus enabling the printing of complex-shaped bodies. It has proven advantageous if these grooves (103) are narrower but deeper than the recesses (101).

[0016] The above-mentioned object is achieved in a second aspect of the present invention by a doctor head (3) comprising at least one bolt (301) having at its first end (301a) an engagement device (303) for receiving a squeegee rubber (1), a base body (305) with at least one bolt guide (307), each bolt guide (307) receiving and guiding the shaft (301s) of a bolt (301), at least one element (309) for receiving at least one spring (311) for generating a contact pressure of the at least one bolt (301), the element (309) being arranged above the bolt guide (307) in the base body (305) and the spring (311) being operatively connected to the second end (301b) of the bolt (301), at least one device (313) for generating a preload in the spring (311), which is received in a two-part clamping system (315a, 315b), the device (313) being formed by a clamping strip (315b) can be secured reversibly.

[0017] "Squeegee head" refers to a device that accommodates a squeegee rubber (1) in corresponding engagement devices (303) and resiliently mounts it so that the squeegee rubber (1) evenly applies the screen to the body to be printed. In practice, several squeegee heads (3) are mounted side by side, depending on the height of the print image to be applied to the body to be printed. The length of the squeegee rubber (1) is preferably 5 mm longer than the print image to be applied.

[0018] The "bolts" with their engagement device (303) serve to hold the squeegee rubber (1), while the shaft (301s) of each bolt (301) is spring-mounted in the base body (305), is guided by the bolt guide (307) and presses the squeegee rubber (1) against the printing screen, which is located above the body to be printed.

[0019] In a further development of the bolt (301) according to the invention, the bolt has a thread at its end opposite the engagement device (303), onto which a securing element (319) can be screwed, the cross-section of which is slightly larger than the shaft (301s) of each bolt (301). This prevents the bolt from slipping downward through the bolt guide (307) toward the body to be printed. The securing element (319) is guided in a corresponding bore of the element (309), in which the spring (311) is also guided. This can be, for example, a screw sleeve.

[0020] According to the invention, the "element for receiving at least one spring" serves to receive the second end (301b) of the bolt (301) and to guide the spring (311) operatively connected thereto and to support it against the bolt (301).

[0021] According to the invention, the "device for generating a preload in the spring" serves for support, which prevents the spring (311) from slipping out of the element (309) and at the same time enables the preload in the spring (311) to be varied.

[0022] The device (313) is accommodated in a two-part clamping system (315a, 315b) and is simultaneously reversibly secured by this. In particular, the clamping bar (315b) ensures that the preload in the spring (311) set by the device (313) is not altered, for example, by vibrations of the squeegee head (3) during use.

[0023] The wording "above the bolt guide (307)" means that the element (309) is arranged on the side of the bolt guide (307) facing away from the squeegee rubber (1).

[0024] The present invention, embodied as a squeegee head (3), has the general advantage that, in contrast to the existing solution, higher print qualities can be achieved with shorter setup times. Furthermore, the present invention opens up a significantly wider range of applications for screen printing, since the squeegee head (3) according to the invention—including the squeegee rubber (1) according to the invention—can also be used to print on soft plastic bottles or other flexible bodies.

[0025] The squeegee head (3) according to the invention further has the advantage that the bolts (301) accommodated therein are mounted securely and smoothly, whereby the preload of the spring (311) and thus the contact pressure of each individual bolt (301) can be individually adjusted. In this way, for example, a pre-adjustment to the contour of the body to be printed can be made. Furthermore, the squeegee rubber (1) can be optimally pressed in this way.

[0026] It is particularly preferred for the squeegee head (3) according to the invention if the squeegee rubber (1) intended for reception is a squeegee rubber (1) according to the invention, as defined above and in the claims.

[0027] The engagement device (303) for receiving a squeegee rubber (1), which the at least one bolt (301) has at its first end (301a), is designed such that it positively engages the recesses (101) of length b1 and depth t1 of the squeegee rubber (1) according to the invention. If multiple bolts (301) are present, the respective engagement devices (303) engage the adjacently arranged recesses (101) of the squeegee rubber (1) according to the invention.

[0028] The combination of the squeegee rubber (1) according to the invention and the squeegee head (3) according to the invention advantageously ensures that the squeegee rubber (1) according to the invention is picked up and held without slippage.

[0029] A preferred embodiment of the doctor head (3) according to the invention provides that the base body (305) has at least two bolt guides (307a, 307b) arranged one above the other, which are separated by a spacer block (317), wherein each bolt guide (307a, 307b) and the spacer block (317) receives and guides the shaft (301s) of a bolt (301), wherein at least one bolt (301) is guided in the base body (305), wherein the at least one bolt (301) and the bolt guide (307) are made of hardened steel.

[0030] In this preferred embodiment, the bolt guide (307) is divided into two separate elements (307a, 307b) and the spacer block (317) is arranged between them. The spacer block (317) is preferably made of a different material than the hardened steel of the bolt guides (307a, 307b), particularly preferably aluminum. The softer material of the spacer block (317) creates a distance between the two parts of the bolt guides (307a, 307b), so that the bolts (301) can be guided permanently without lubricant. The spacer block (317) maintains the necessary minimum distance. Lubrication-free operation is important to prevent the lubricant from coming into contact with the printing ink and contaminating it.

[0031] Furthermore, manufacturing the bolt guide (307) with two separate elements (307a, 307b) and a spacer block (317) is significantly more cost-effective than a monolithic bolt guide (307). Finally, the split bolt guide (307) is significantly easier to clean than prior art bolt guides.

[0032] It has proven advantageous to provide additional external bores in the elements (307a, 307b) of the bolt guide (307) and in the spacer block (317), which are provided with centering pins to connect the individual parts in precise alignment. The additional bores with centering pins can extend into the element so that the entire base body (305) can be aligned.

[0033] An advantageous development of the doctor head (3) according to the invention provides that at least the element (309) has a symmetrical cross-sectional area relative to the plane parallel to its direction of movement. In other words, this refers to the plane that is at right angles to the adjacently arranged bolts (301). Preferably, the entire base body (305) is designed symmetrically in this way.

[0034] This further development has the advantage that the entire squeegee head (3) can be removed from its attachment to the printing device and easily reattached after being rotated by 180 degrees in order to change the printing direction in the opposite direction.

[0035] According to the invention, it is preferred if the shaft (301s) of each bolt (301) has a square cross-section, which is guided in a rotationally secure manner at least by the shape-equivalent bolt guide (307). The recess in the spacer block (317), however, is larger than the shape-equivalent guides in the elements (307a, 307b) of the bolt guide (307). The bolts (301) must not come into contact with the spacer block (317), as otherwise trouble-free operation is not possible. In this way, it is prevented that the squeegee rubber (1) is also rotated by rotating one or more bolts (301) and, in the worst case, no longer rests completely on the screen above the workpiece to be printed.

[0036] The angular cross-section can have various numbers of corners, as long as the anti-twist protection is ensured, although a square cross-section is particularly preferred for the present invention. The edges can be chamfered to ensure smoother running.

[0037] In a further embodiment of the doctor head (3) according to the invention, the bolts (301) are positioned in the base body (305) with a clearance B between them that is at most half the width of the shaft (301s). "Clearance" here refers to the space between two adjacent bolts (301).

[0038] Because the bolts (301) are arranged so closely together in this specific embodiment, the squeegee rubber (1) can be pressed very securely against the workpiece to be printed, following virtually any contour. This close arrangement allows for the use of narrower, thinner squeegee rubbers (1) that offer greater flexibility compared to the prior art. Due to the close arrangement, even smaller contours can be printed with the present invention. Furthermore, peak loads on the printhead can be avoided.

[0039] A further development of the bolts (301) according to the invention provides that they have concave formations (301k) between one another at the transition from the shaft (301s) to the engagement device (303), which reduce the width of the shaft (301s) and increase its depth, wherein the concave formations (301k) form a distance A. This leads to the advantage that the engagement device (303) has some flexibility with respect to the shaft (301s) in the lateral direction, i.e. in the direction in which the squeegee rubber (1) extends, while the stability in the direction of movement of the squeegee rubber (1) is maintained. The squeegee rubber (1) can thus be guided securely and in a fully snug fit even with more pronounced contours of the body to be printed.

[0040] Furthermore, the length b1 of the recesses (101) is smaller than the width b3 of the engagement device (303), which contributes to a secure hold of the squeegee rubber (1).

[0041] The above embodiment is advantageously further developed such that the width of a support surface (301f) for the squeegee rubber (1) in the engagement device (303) is reduced by at least 50% compared to the width of the bolt (301) by the concave formations (301k).

[0042] Advantageously, the contact surface (301f) of each engagement device (303) of a bolt is significantly reduced by the concave formations (301k), thereby significantly increasing the flexibility of the squeegee rubber (1). Specifically, a clearance A is formed between two adjacent concave formations (301k), which is significantly larger than the clearance B between the bolts (301).

[0043] A special embodiment of the doctor blade head according to the invention relates to the two-part clamping system (315a, 315b). This two-part clamping system (315a, 315b) can be designed in a first part (315a) above the element (309) for receiving the spring (311) in such a way that it has first threaded holes (315a1) aligned with the bolts (301) and the spring (311) located in the element (309), as well as further second threaded holes (315a2), wherein the device (313) for generating the preload can be screwed into the first threaded hole (315a1).

[0044] Additionally or alternatively, the two-part clamping system (315a, 315b) can be designed in a second part (315b) above the first part (315a) in such a way that the clamping strip (315b) can be fastened by means of a second threaded bore (315a2), which has a flexible lip (315g) oriented towards the device (313) for generating the preload, which lip rests on the external thread of the latter and serves to secure it.

[0045] The first embodiment ensures that the device (313) for generating the preload is in linear operative connection with the spring (311), and that the preload can be changed by screwing it in or out. At the same time, the bolts (301) are mounted in the bolt guide (307) in a rotationally secure manner, while the spring (311) is accommodated in the element (309).

[0046] The second embodiment advantageously provides a locking mechanism for the device (313) with the clamping strip (315b), preventing it from becoming displaced during operation of the squeegee head (3), for example due to vibrations, and thus inadvertently changing the preload of the spring (311). The flexible lip (315g) can preferably be a rubber lip or the like.

[0047] The prior art also provides safeguards to prevent preload adjustment, but these essentially consist of threaded nuts that must be tightened individually for each conventional bolt. It is possible to adjust the originally set preload by turning the threaded nut itself. In contrast, the clamping strip (315b) according to the invention can simultaneously secure a plurality of devices (313) against adjustment without the devices (313) having to be moved.

[0048] It has proven advantageous for the maintenance and, if necessary, repair of the squeegee head (3) according to the invention if its components can be reversibly disassembled and replaced separately. This allows individual parts to be replaced quickly and easily without having to replace the entire squeegee head (3). This also reduces costs.

[0049] A doctor head (3) according to the invention accommodates at least one bolt (301) including a spring (311) and a device (313). From a practical point of view, however, it has proven useful to provide two bolts (301), better three bolts (301), particularly preferably four bolts (301) and up to eight bolts (301), each including a spring (311) and a device (313). However, there is no upper limit to the number of bolts (301) in a doctor head (3) as long as the number is technically feasible. It is also conceivable that doctor heads (3) could be designed with 10 or 20 bolts (301) next to one another.

[0050] In a third aspect of the present invention, the above-mentioned object is achieved by a doctor blade system (5) comprising at least one doctor head (3) as described above, a doctor rubber (1) as described above, wherein the squeegee rubber (1) is received in the engagement devices (303) in the bolt (301).

[0051] The present invention in the form of a doctor blade system (5) also generally has the advantage that, in contrast to the existing solution, higher print qualities can be achieved with shorter set-up times.

[0052] The squeegee system (5) according to the invention combines all the above-described advantages of the squeegee rubber (1) and the squeegee head (3) and offers a compact and functional solution for squeegee-based screen printing. Furthermore, the present invention opens up a significantly broader range of applications, since the squeegee head (3) according to the invention, including the squeegee rubber (1), can also be used to print on soft plastic bottles or other flexible bodies.

[0053] In particular, the squeegee heads (3) according to the invention are significantly narrower than comparable models of the prior art. In addition to the more precise printing technology already mentioned above, another important advantage of the present invention lies in the number of pins (301) per centimeter of squeegee rubber (1). According to the prior art, one pin per centimeter of rubber can be achieved, whereas in the present invention, at least two pins per centimeter of squeegee rubber (1) can be arranged side by side.

[0054] Further objects, features, advantages, and possible applications will become apparent from the following description of non-limiting embodiments of the invention, taken in conjunction with the figures. All described and / or illustrated features, individually or in any combination, constitute the subject matter of the invention, regardless of their summary in the claims or their references. They show: Fig. 1: a schematic representation of a squeegee rubber 1 according to the invention, Fig. 2: a schematic representation of a squeegee rubber 1 according to the invention, which is received in engagement devices 303 of the bolts 301, Fig. 3a: a schematic representation of a squeegee rubber 1 according to the invention, which is received in engagement devices 303 of the bolts 301, Fig. 3b: a schematic detailed representation of the squeegee rubber 1 according to the invention, Fig. 4: a schematic detailed representation of a bolt 301 at different angles, Fig. 5: a schematic perspective representation of a fully assembled squeegee head 3 according to an embodiment of the invention, Fig. 6: a schematic side representation of a fully assembled squeegee head 3 according to an embodiment of the invention, Fig. 7: a schematic representation of four bolts 301 with springs 311 and devices 313 arranged above them, Fig.Fig. 8a: a schematic plan view of the doctor head 3 according to an embodiment of the invention, Fig. 8b: a schematic sectional view of the doctor head 3 according to an embodiment of the invention, and Fig. 9: a schematic exploded view of the two-part clamping system 315a, 315b.

[0055] The same reference symbols designate the same elements in the figures, but for reasons of clarity not all reference symbols are given in all figures.

[0056] In Figure 1 is a schematic representation of a squeegee rubber 1 according to the invention having, in the longitudinal direction on the side opposite the squeegee edge 105, recesses 101 of length b1 and depth t1 for slip-free reception of the squeegee rubber 1 in an engagement device 303 on a squeegee head 3 and further grooves 103 of length b2 and depth t2 for increasing the flexibility of the squeegee rubber 1 in the longitudinal direction, which are arranged between the recesses 101.

[0057] Figure 2 schematically illustrates a squeegee rubber 1 according to the invention, which is received in engagement devices 303 of the bolts 301. The illustration clearly shows how the engagement devices 303 are received in the recesses 101 of the squeegee rubber 1, while the grooves 103 remain free therebetween.

[0058] In Figure 3a the view of the Figure 2 shown again in a schematic side view, while the detailed representation of the Figure 3b the arrangement and dimensions of the recesses 101 (length b1, depth t1) and the grooves 103 (length b2, depth t2). In this illustration of the Figure 3a It is also clear that the width b3 of the engagement device 303 is greater than the length b1 of the recesses 101 to ensure a secure fit. Also highlighted is the concave formation 301k of the bolt 301 to increase flexibility.

[0059] A bolt 301 according to the invention is Figure 4 shown schematically at different angles. Important here are the concave formations 301k, which have a direct influence on the width of the support surface 301f for the squeegee rubber 1 in the engagement device 303. The width of the support surface 301f is reduced by at least 50% compared to the width of the bolt 301. This smaller support surface 301f significantly increases the flexibility of the squeegee rubber 1, while the previously described design of the squeegee rubber 1 itself, in conjunction with the engagement device 303, ensures optimal hold of the squeegee rubber 1.

[0060] Especially with irregularly shaped surfaces, different forces act on the squeegee rubber 1. This leads to the squeegee rubber 1 wanting to move sideways, see in Figure 3aeither to the right or to the left. The recesses 101 according to the invention prevent this lateral displacement.

[0061] A fully assembled doctor head 3 according to an embodiment of the invention is shown in a perspective view in Figure 5 shown. The squeegee head 3 according to the invention initially comprises a base body 305 with an element 309 and at least one bolt guide 307 for at least one bolt 301, which has an engagement device 303 at its first end 301a for receiving the above-described squeegee rubber 1. Each bolt guide 307 receives the shaft 301s of a bolt 301 and guides it. In the illustrated embodiment, the squeegee head 3 has four bolts 301.

[0062] In principle, the number of bolts 301 is not limited to one centimeter of the squeegee rubber 1. However, a practical difficulty is that the spring pressure above each bolt 301 is individually adjustable and each device 313 must be able to be secured. This becomes even more difficult the more bolts 301 are located close together.

[0063] Furthermore, an element 309 is provided for receiving at least one spring 311, which generates a contact pressure of the at least one bolt 301. The element 309 is arranged above the bolt guide 307 in the base body 305. The spring 311 is operatively connected to the second end 301b of the bolt 301, i.e., it presses on the bolt 301 from above.

[0064] At least element 309 is designed symmetrically in this embodiment; in the present illustration, the entire base body 305 is also symmetrical. This symmetry refers in particular to the two opposing projections for fastening in / to the printing device. As already described above, this allows for a simple and quick rotation of the squeegee head 3 by 180 degrees and thus a simple and quick reversal of the printing direction.

[0065] To preload the spring 311, a device 313 is provided for generating this preload, which is housed in a two-part clamping system 315a, 315b. The two-part clamping system has a clamping bar 315b, by which the device 313 can be reversibly secured. This prevents the device 313 from accidentally being adjusted during operation.

[0066] In the illustrated embodiment, the base body 305 has at least two bolt guides 307a, 307b arranged one above the other, separated by a spacer block 317. As already explained above, this arrangement serves to provide lubrication-free support for the bolts 301. Each bolt guide 307a, 307b receives and guides the shank 301s of a bolt 301. At least the bolts 301 and the bolt guide 307 are made of hardened steel.

[0067] Figure 6 shows the squeegee head of the Figure 5 once again from the side, whereby it is particularly clear how the terminal block 315b rests against the device 313 in order to secure it reversibly.

[0068] In Figure 7 four bolts 301 with springs 311 and devices 313 arranged above them are shown, as they are inside the doctor head 3 from the Figure 4 and 5are arranged. To clarify the individual elements, only one spring 311 is shown here. The individual bolts 301 have a locking element 319 at their upper end, which is only indicated here. The locking element 319 prevents the bolt 301 from slipping downward out of the bolt guide 307a, 307b. The guides within the base body 305, however, are wide enough for the locking elements 319 to slide securely within them.

[0069] Figure 8a shows the above-described squeegee head 3 schematically from above, in particular the two-part clamping system 315a, 315b. Here, it is shown again how the clamping bar 315b rests against the devices 313. S2 indicates screws (cylinder head with hexagon socket M4x50), which in this embodiment are accommodated in element 309. The two other openings AS1 serve to accommodate the screws S1, which are not shown here.

[0070] Figure 8ashows a section line B - B, whose intersection in Figure 8b This shows how the screw S2 passes through the element 309 into the lower bolt guide 307b, which has an M4 thread for screwing in. This design offers the possibility of loosening the two screws S2 and removing the unit consisting of bolt guides 307a, 307b, spacer block 317, and the bolt 301 accommodated therein, and reinserting it after being rotated 180°. This allows the squeegee direction, indicated by an arrow in the figure, to be easily reversed.

[0071] By the element 309 according to the invention, which as in Figure 8bSince the squeegee head 3 is clearly shown to be symmetrically constructed and has two projections for attachment in / on the printing device, the present invention makes it even easier to change the printing direction. In practice, the machine setter will use the opposite projection to attach the squeegee head 3 to change the printing direction. Thus, according to the present invention, there are two ways to change the printing direction.

[0072] The Figure 9is a schematic exploded view of the two-part clamping system 315a, 315b, whereby this embodiment has two terminal blocks 315b, which are screwed onto the symmetrically designed element 315a. 315a1 denotes the threads for receiving the devices 313, while 315a2 indicates the thread for securing the terminal block 315b. In the exploded view, three devices 313 are screwed in and one device 313 is unscrewed. 315a2 shows a thread into which the screw 315a3 is screwed. This serves to fasten the respective terminal block 315b to the element 315a of the two-part clamping system 315a, 315b. At the point marked Z is the screw head for the screw S2, which in Figure 8a from above and in Figure 8b is shown in section. Figure 9also shows the position of this screw. Diagonally opposite is the second screw S2, which in this illustration is concealed by the screwed-in devices 313.

[0073] The terminal block 315b is shown in perspective in the exploded view, from which the flexible lip 315g, here in the form of a rubber lip, emerges, which rests against the devices 313 during attachment.

[0074] The element 315a is attached to the element 309 using the screws S1. The heads of the screws S2, see also Figure 8a , are predominantly located in element 309. In addition, the screws S2 also serve to connect the bolt guides 307a, 307b and the spacer block 317 to the element 309. Furthermore, the top sides of the heads of the screws S2 also serve to center the element 315a. Reference symbol

[0075] 1 Squeegee rubber 101 Recesses 103 Grooves 105 Squeegee edge 3 Squeegee head 301 Bolt 301a First end 301f Support surface for the squeegee rubber 1 301k Concave formations 301s Shaft 303 Engagement device 305 Base body 307 Bolt guide 307a, 307b Bolt guides 309 Element for receiving at least one spring 311 Spring 313 Device for generating a preload 315 Two-part clamping system 315a, 315b 315b Clamping strip 315a1 First threaded holes 315a2 Second threaded holes 315a3 Screw 315g Flexible lip 317 Spacer block 319 Securing element 5 Squeegee system AClearance between concave formations 301k BClearance between two adjacent bolts 301 b1Length of the recesses 101 b2Length of the grooves 103 b3Width of the engagement device 303 M4Thread S1, S2Screws AS1Receptacles of the screws S1 t1Depth of the recesses 101 t2Depth of the grooves 103 ZScrew receptacle

Claims

1. Squeegee rubber (1) with a squeegee edge (105), comprising in the longitudinal direction of the squeegee rubber (1) on the side opposite the squeegee edge (105) recesses (101) of length b1 and depth t1 for slip-free reception of the squeegee rubber (1) in an engagement device (303) on a squeegee head (3).

2. Squeegee rubber (1) according to claim 1, further comprising grooves (103) of length b2 and depth t2 in the longitudinal direction of the squeegee rubber for increasing the flexibility of the squeegee rubber (1) in the longitudinal direction, which grooves are arranged between the recesses (101).

3. Squeegee head (3) comprising - at least one bolt (301) having an engagement device (303) for receiving a squeegee rubber (1) at its first end (301a), - a base body (305) with at least one bolt guide (307), each bolt guide (307) receiving and guiding the shaft (301s) of a bolt (301), - at least one element (309) for receiving at least one spring (311) for generating a contact pressure of the at least one bolt (301), the element (309) being arranged above the bolt guide (307) in the base body (305) and the spring (311) being operatively connected to the second end (301b) of the bolt (301), - at least one device (313) for generating a preload in the spring (311), which is received in a two-part clamping system (315a, 315b), the device (313) can be reversibly secured by a terminal block (315b).

4. Squeegee head (3) according to claim 3, wherein the squeegee rubber (1) provided for receiving is a squeegee rubber (1) according to one of claims 1 or 2.

5. Doctor head (3) according to claim 3 or 4, wherein the base body (305) has at least two bolt guides (307a, 307b) arranged one above the other, which are separated by a spacer block (317), wherein each bolt guide (307a, 307b) and the spacer block (317) receives and guides the shaft (301s) of a bolt (301), wherein at least one bolt (301) is guided in the base body (305), wherein at least the bolts (301) and the bolt guide (307) are made of hardened steel.

6. Doctor head (3) according to one of claims 3 to 5, wherein at least the element (309) has a symmetrical cross-sectional area with respect to the plane parallel to its direction of movement.

7. Doctor head (3) according to one of claims 3 to 6, wherein the shaft (301s) of each bolt (301) has a square cross-section which is guided in a rotationally secure manner at least by the shape-equivalent bolt guide (307).

8. Doctor head (3) according to one of claims 3 to 7, wherein the bolts (301) are positioned in the base body (305) with a clearance B relative to one another which is at most half the width of the shaft (301s).

9. Doctor head (3) according to one of claims 3 to 8, wherein the bolts (301) at the transition from shaft (301s) to engagement device (303) have concave formations (301k) between each other, which reduce the width of the shaft (301s) and increase its depth, wherein the concave formations (301k) form a distance A.

10. Squeegee head (3) according to claim 9, wherein the width of a support surface (301f) for the squeegee rubber (1) in the engagement device (303) is reduced by at least 50% compared to the width of the bolt (301) by the concave formations (301k).

11. Doctor head (3) according to one of claims 3 to 10, wherein the two-part clamping system (315a, 315b) is designed in a first part (315a) above the element (309) for receiving the spring (311) in such a way that it has first threaded bores (315a1) aligned with the bolts (301) and the spring (311) located in the element (309) and further second threaded bores (315a2), wherein the device (313) for generating the pretension can be screwed into the first threaded bore (315a1). and / or the two-part clamping system (315a, 315b) is designed in a second part (315b) above the first part (315a) in such a way that the clamping strip (315b) can be screwed into a second threaded bore (315a2), said clamping strip having a flexible lip (315g) oriented towards the device (313) for generating the preload, which lip rests on the external thread of the latter and serves to secure it.

12. Squeegee head (3) according to one of claims 3 to 11, the components of which can be reversibly dismantled and replaced separately.

13. Squeegee system (5) comprising - at least one squeegee head (3) according to one of claims 3 to 12, - a squeegee rubber (1) according to one of claims 1 or 2, wherein the squeegee rubber (1) is received in the engagement devices (303) in the bolt (301).

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