EP0453792B1 - Ink metering device with pivoting ink fountain - Google Patents

Abstract

1. For accurate ink metering in printing machines, ink fountains with ink metering elements are supported on ink fountain rollers. In this connection, weight influences are intended to be minimised and handling problems eliminated. <??>2. The ink fountain 1 is supported via cam rollers 5, 6, 8 on bows 4, 7 on the surface of the ink fountain roller 2. The ink fountain 1 rests by means of support rollers 3 on rolling surfaces 12 on the machine frame. To clamp the ink fountain 1 to the ink fountain roller 2, the bow 7 is pivotable about the axis of the cam roller 6 and can be set, loaded with springs 9, against the ink fountain roller 2. For setting against the ink fountain roller 2 or for pivoting off and returning via the rolling surface 12, a lever drive is used. On running up against the stop 13, the ink fountain 1 tips backwards and can be cleaned. The pivoting device can also be executed simply as a pivoting mechanism. <??>3. The ink fountain 1 is aligned with minimal action of force on the ink fountain roller 2. Weight differences as a result of filling and consumption of printing ink have no effect on the ink metering. Operability for cleaning and maintenance is optimised. <IMAGE>

Description

The invention relates to a device for guiding an ink fountain of a printing press according to the preamble of patent claim 1.

A device of this type is described in DE-PS 3 033 998.

The ink is fed in offset printing machines with the aid of ink metering elements in an ink fountain, which interacts with an ink fountain roller. A differently profiled ink layer is generated on the ink fountain roller, which results from the positioning of the ink metering elements relative to the ink fountain roller. In order to achieve the best possible reproducibility of these ink layers, an exact storage of the ink fountain relative to the ink fountain roller is necessary. It should also be borne in mind that deformations in the ink fountain area and on the ink fountain roller result from the weight and high viscosity of the relatively tough printing ink. On the other hand, the ink fountain should also be able to be parked so far away from the ink fountain roller for cleaning and adjustment purposes that optimum operation is possible.

In order to minimize the deformations on the ink fountain roller or on the ink fountain, it is proposed in a storage for a ink fountain according to DE-OS 3 033 998 to store the ink fountain on both roller journals of the ink fountain roller between the two side frames. For this purpose, a support ring, for example in the form of a roller bearing, is provided on the roll neck, around which a holder for fastening the Color box is put around. The adjustment is made with the help of a tensioning element that connects the holder (eg steel band) to the ink fountain. The ink fountain is attached to the machine frame using retaining pins in enlarged holes on the ink fountain. The coupling between the ink fountain and the holding pin is elastic. In this way, the ink fountain can be slightly lifted out of its frame-fixed bearings when it is placed against the ink fountain roller.

This arrangement is particularly disadvantageous in that the weight of the ink and ink fountain directly affected its suspension. In addition, when the ink fountain is placed on the ink fountain roller, additional forces act on the ink fountain roller from the elastic mounting on the holding pin. Furthermore, the ink fountain can only be in the defined pivot point of the holding pins, i.e. very close to the ink fountain roller, swiveled. The ease of use is poor because the loosening and fastening of the clamping device is cumbersome and accessibility is hindered.

Another arrangement is shown in a paint metering device according to DE-PS 3 427 909. Here the ink fountain is supported by cam rollers on the surface of the ink fountain roller. In order to ensure the permanent contact of the cam rollers on the ink fountain roller, the ink fountain is turned against the ink fountain roller from the machine frame with a lever drive and a relatively stiff spring assembly. The ink fountain is also lifted out of a swivel bearing that is fixed to the frame.

This arrangement has the disadvantage that relatively large forces have to be applied in order to be able to place the ink fountain securely against the surface of the ink fountain roller. The forces must be at least as great that the ink fountain is set up with sufficient force even when fully loaded with printing ink. These forces act on the ink fountain roller at all times and of course bend it. Depending on the loading condition of the ink fountain, however, the deflection changes in that there is a minimal deflection when the ink fountain is fully loaded and a maximum deflection of the ink fountain roller when the ink fountain is largely empty. The tight guidance of the ink fountain on the ink fountain roller also does not allow the ink collection space below the metering elements to be designed in such a way that it is easy to clean and has a volume that is sufficient for a long service life.

Accordingly, the printing ink to be introduced into the ink fountain and its effect due to weight and hydrodynamics in connection with the manufacturing tolerances in relation to the ink fountain roller must be considered as a particular problem for the exact positioning.

Also known from EP 0 339 711 A1 is a device for printing objects, such as cups made of synthetic material and the like. It has paint boxes that are slidably placed on a support in a housing. The ink fountains are arranged so that they can be set against the associated ink fountain roller. They are supported on the surface of the respective ink fountain roller by means of rollers which are attached to the side walls of the ink fountain.

In addition, a color box for printing presses, reproducers or the like is known from GB-PS 1,111,182. The ink fountain described has a foldable plate, with the aid of which a flexible ink container inserted into the ink fountain can be pressed out. The color box is on a fixed frame Axis can be swiveled in and out relative to an ink fountain roller. For this purpose, an arrangement of operating elements is provided which controls the pivoting movement of the ink fountain guided by a hand lever.

The object of the invention is therefore to improve a device according to the preamble of claim 1 so that its adjustment largely independent of the weight of the printing ink to be introduced into the ink fountain, but thereby an exactly reproducible setting of the metering elements and a compensation of manufacturing tolerances on the ink fountain roller or ink fountain enables, and otherwise achieved an improvement in operation by further pivoting the ink fountain.

The solution of the problem is obtained according to the characterizing part of patent claim 1. In this new device for guiding an ink fountain, it is particularly advantageous that the weight of the ink fountain itself or the weight of the printing ink to be introduced is intercepted in a special storage. The color box but the surface follow the ink fountain roller as a reference surface for ink metering. The different loading of the ink fountain with printing ink no longer has an adverse effect on the ink dosage. The entire arrangement is largely free of force and only introduces minimal external bending moments into the ink fountain roller. Due to the better swiveling of a special embodiment, operation and cleaning of the ink fountain are made considerably easier. In addition, the collecting space for printing ink emerging on the underside of the metering elements is considerably enlarged.
The ink fountain is locked to the ink fountain roller by internal forces. Operation is extremely simple and safe.

An exemplary embodiment of the invention is explained below with the aid of some drawings.

Figur 1

eine schematische Darstellung Farbkastens nach der Erfindung,

Figur 2

eine Ausführungsform im angeschwenktem Zustand,

Figur 3

eine Ausführungsform im abgeschwenktem Zustand,

Figur 4

Halterungselemente am Gestell,

Figur 5

eine Seite der Führung an der Farbkastenwalze in Draufsicht,

Figur 6

eine Draufsicht einer Traverse.

In detail shows

Figure 1

1 shows a schematic illustration of ink fountain according to the invention,

Figure 2

an embodiment in the pivoted state,

Figure 3

an embodiment in the pivoted state,

Figure 4

Mounting elements on the frame,

Figure 5

one side of the guide on the ink fountain roller in top view,

Figure 6

a top view of a traverse.

In the description of the figures, it can be assumed that the means mentioned for one side of the arrangement are also present in mirror image on the other side.

In Figure 1, the operative relationship between an ink fountain 1 and its holder on an ink fountain roller 2 is shown. This shows in particular how the forces from the ink fountain 1 and holder are introduced into the ink fountain roller 2 or other elements. The ink fountain 1 itself is supported on a support roller 3 fixed to the frame. This support roller 3 takes up the main weight of the ink fountain 1 and the printing ink present therein. Connected to the ink fountain 1 is a bracket 4 at the two ends of which cam rollers 5, 6 are provided. The cam rollers 5, 6 run on the surface of the ink fountain roller 2. A second bracket 7, which likewise carries a cam roller 8, is movably connected to this first bracket 4. Between the first bracket 4 and the second bracket 7, a suspension 9 is provided which acts in such a way that the second bracket 7 is sprung with its cam roller 8 against the surface of the ink fountain roller 2. The suspension is supported on the first bracket 4 and in this way pulls or presses the cam roller 5 against the surface of the ink fountain roller 2. The arrangement of the cam rollers 5, 6, 8 is selected so that the first cam roller 5 lies in the plane , in which there are also color metering elements 10 of the ink fountain 1. The spring-loaded cam roller 8 of the second bracket 7 is diagonally or at least approximately diagonally opposite this first cam roller 5. The second cam roller 6 on the first bracket 4 is meanwhile located on the top of the ink fountain roller 2, so that its bearing force acts in a vertical direction on its surface. The weight forces from ink fountain 1 and printing ink are now distributed to the support roller 3 fixed to the frame and the support of the second cam roller 6 on the ink fountain roller 2. Since the support roller fixed to the frame 3 is located closer to the center of gravity of the ink fountain 1, the main weight will accrue there. The weight force acting on the ink fountain roller 2 is thus minimized and limited to a proportion necessary for reliable guidance. The contact force in the area of the color metering elements 10 is applied by internal forces in the bracket system 4, 7. It is no longer necessary to generate a contact force between the machine frame 11 and the ink fountain roller 2. This means that no bending moment can be introduced into the ink fountain roller 2 at this point. Nevertheless, due to the attachment in the manner of a clamping of the ink fountain 1 with the bracket system 4, 7 on the ink fountain roller 2, secure guidance is ensured. The ink fountain 1 and thus also the ink metering elements 10 follow the surface of the ink fountain roller exactly despite all manufacturing inaccuracies such as out-of-roundness or eccentricity. The reproducibility and accuracy of the dosing element adjustment is always guaranteed.

The changes in the force effects on the ink fountain 1 due to the filling of printing ink are limited to a minimum. The change in force on the ink fountain 1 or on the ink fountain roller 2 from the loading with printing ink is largely absorbed by the roller 3 fixed to the frame, which carries the ink fountain 1 yes. The remaining portion that is introduced into the ink fountain roller 2 via the cam roller 6 can no longer produce any significant bend there.

To turn off the ink fountain 1 with handling aids such. B. connected to a lever drive, not shown here, or a worm drive, which are coupled to the bracket 7 and its suspension 9. To swivel the ink fountain 1, an unlocking mechanism is provided with which the second bracket 7 can be raised slightly so that it can be moved over the high point of the roller surface when swiveled out, as shown in broken lines in FIG. To the To be able to pivot ink fountain more easily and further from ink fountain roller 2, a roller conveyor 12 is provided below ink fountain 1, on which ink fountain 1 is supported with support roller 3. When swiveling the ink fountain 1 moves up to a stop 13 at the end of this runway 12 and is then pivoted backwards about the support roller 3. He is held by the handling aid. Due to the low position of the pivot point, the ink fountain 1 can be pivoted particularly far back from the ink fountain roller 2. A paint tray on the front of the ink fountain 1 is then freely accessible on the surface. The ink fountain can therefore be made larger because the ink fountain is first moved horizontally and only then swiveled. This makes the ink fountain more receptive to running ink and also easier to clean.

In Figure 2, the ink fountain bracket is shown constructed. Here an ink fountain roller 14 with the ink fountain 15 is shown. Since the drawing is designed as a side view, the ink fountain 15 is covered in its essential parts by the ink fountain bracket. The ink fountain 15 is supported with a support rail 16 attached to its underside in a swivel bearing 17 which is fixed to the frame in a cross member 18. A holding element, which consists of brackets 20 and a cable bushing 21, is fastened to an ink fountain side wall 19. On the cable bushing 21, two brackets 20 are arranged parallel to the ink fountain roller 14 in the axial direction. A cam roller 23 is arranged on an axis 22 between the brackets 20 in the area of the ink metering elements 10. At the upper end of the bracket 20, a further cam roller 25 is arranged on a further axis 24. A pivot bracket 26 is arranged on the same axis 24 and encompasses the cam roller 25. A third cam roller 28 is seated on the swivel bracket 26 at the outer end on an axis 27. The opposite end of the swivel bracket 26 is shown in FIG an axis 29 connected to a spring support 30. The spring support 30 is supported on the axle 29 with a plate spring assembly 31. It is connected at the other end in a pivot point 32 to an unlocking element 33. The unlocking element 33 is held on an axis 34 between the brackets 20. A handle 35 is arranged on the unlocking element 33 and can be displaced in the longitudinal direction against a spring. A rubber buffer 36 is also attached to the unlocking element 33.

The parts unlocking element 33, spring support 30 and swivel bracket 26 form a lever system that can be pushed over. By means of the handle 35, the lever system can be pivoted in the swung-in state of the ink fountain 15 against the force of the plate spring assembly 31 into its overpressure position, so that the cam roller 28 rests on the surface of the ink fountain roller 14. The ink fountain 15 rests in this position on the pivot bearing 17 and the cam roller 25. The focus of the ink fountain lies a little to the right next to the vertical above the pivot bearing 17, so that the entire ink fountain 15 rests almost on the ink fountain roller 14. This also ensures that the cam roller 23 rests securely on the surface of the ink fountain roller 14. Since the ink metering elements 10 also lie in the plane in which the two cam rollers 23 are located, a secure reference position for the adjustment of the ink metering elements 10 is thus provided. In order to ensure absolutely reliable guidance for all operating states of the ink fountain system, the cam roller 28 is set with the swivel bracket 26 to clamp the ink fountain 15 on the ink fountain roller 14 via the lever system. Basically, it is sufficient if the cam roller 28 lies diagonally opposite the cam roller 23. For safety reasons, but the encasement of the ink fountain roller 14 between cam roller 23 and cam roller 28 may, including the cam roller are slightly greater than 180 chosen ^o 25th

In Figure 3, the pivoted position of the ink fountain 15 is shown. To swivel the handle 35 against its spring force, pull it up out of its holder and move it backwards. The unlocking element 33 pivots about the axis 34 and pulls the spring support 30 downwards. As a result, the overpressure of the lever system is released and at the same time the swivel bracket 26 together with the cam roller 28 is pivoted upward away from the ink fountain roller 14. The ink fountain 15 is thus free and can be pivoted backwards from the ink fountain roller 14 on the handle 35 or the handles 35 in the pivot bearing 17. In the position described, the lower extension 37 of the handle 35 engages in a locking hole 38 on the cable bushing 21, as a result of which the lever system is rigidly locked to the ink fountain 15. In the pivoted-down position, an ink collecting trough 39, which is normally located in its holder 40 on the lower part 41 of the ink fountain 15 below the ink fountain roller 14, is freely accessible. The ink tray 39 can be easily removed for cleaning. In the pivoted-down position, the rubber buffers 36 are also moved into a catch position together with the unlocking element 33. As explained in more detail in FIG. 4, the pivoting position is secured by further rubber buffers.

If the ink fountain 15 is to be pivoted again, it only has to be pushed in the direction of the ink fountain roller 14 using the handles 35. In order to mitigate the impact on the roller surface, the rubber buffers 36 now first hit the surface of the ink fountain roller 14. Then the handles 35 are to be pulled again against the force of the springs and the lever system comprising the unlocking element 33, spring support 30 and swivel bracket 26 can be swiveled back into the overpressed position to secure the ink fountain 15 on the ink fountain roller 14. At the same time, the rubber buffers 36 are pivoted downward from the surface of the ink fountain roller 14.

The assignment of the ink fountain holder to the parts fixed to the frame is explained in more detail in FIGS. 4 and 5. In the pivoted-in state of the ink fountain, the brackets 20 encompass a roller bearing 42 which is mounted on the side frame 43. In the pivoted-off state, the ink fountain lies in the region of the cam rollers 23 with the axis 22 of the cam rollers 23, which axis 22 is extended outward as a stop 44, against further rubber buffers 45. The rubber buffers 45 are mounted on a cable duct 46 fixed to the frame, which lies opposite the cable duct 21 on the ink fountain 15.

In Figure 5 it is additionally shown that the swivel bracket 26 is designed as a box-shaped part and carries the cam roller 28 between its side walls on the axis 27. Diagonally opposite on the other side of the ink fountain roller 14, the cam roller 23 is arranged on the axis 22. The side walls of the cable bushing 21 to the side of the cam roller 23 form the lower end of the bracket 20, which receive the cam roller 25 on the axis 24 and the swivel bracket 26 at their upper end. The cable duct 21 or the bracket 20 are connected directly to the ink fountain side wall 19, to which the ink metering elements 10 are also connected. A drip plate 47 is indicated in front of the ink metering elements in FIG. The arrangement from FIG. 5 also applies in mirror image to the other side of the ink fountain roller 14.

In Figure 6, the cross member 18 is shown in plan view. The support rail 16 and thus also the ink fountain 15 are supported on the cross member 18. Swivel bearings 17 are let into the cross member 18. As can be seen from FIG. 3, the pivot bearings 17 are inserted into the crossmember 18 as separate bearing elements 48, 49. For the normal case is a narrower bearing element 49 in the middle of the cross member 18 and at the same distance to the side of the bearing element 49 two further bearing elements 48 are provided. The support rail 16 is slightly raised in the middle in the region of the bearing element 49. As a result, in the pivoted-in state, the ink fountain 15 with the support rail 16 rests only on the central bearing element 49, which results in a statically determined support of the ink fountain. A support surface 50 with a height of approximately 0.5 mm is therefore provided in the middle on the support rail 16. In the pivoted-off state, the ink fountain 15 can tip laterally to the left or right onto one of the other bearing elements 48. In order to achieve an axial centering of the ink fountain 15, adjusting blocks 51 are provided on each side of the bearing elements 48, on each of which a countered adjusting screw 52 is arranged. The set screws 52 are set so that a minimal lateral movement of the ink fountain 15 with its support rail 16 can be permitted. In order to secure the cross member 18 against the accumulation of dirt, a cover plate 53 is inserted in such a way that the support rail 16 of the ink fountain 15 remains freely movable.

The handling of the ink fountain 15 is extremely simplified in this way, the load on the ink fountain roller 14 being reduced as much as possible. In addition, the entire ink fountain 15 can be removed from the machine in the simplest way for assembly and disassembly purposes. When reinserting, no complex assembly work is necessary and the adjustment when it is placed against the ink fountain roller 14 is carried out automatically by the ink fountain 15. In addition, no more constraining forces are applied between the machine frame and the ink fountain roller.

For cases of large deviations in the position tolerances or for retrofitting on older printing presses, this can include, among other things be provided that the support surface 50 or, alternatively, the bearing element 49 are adjustable in height. In the normal case, it is irrelevant whether the ink fountain 15 is set slightly higher or lower on the ink fountain roller 14. This results only in a slightly different position for the position of the ink metering elements 10 on the circumference of the ink fountain roller 14, but this position has no influence on the function of the entire arrangement.

Reference list

1

Paint box

2nd

Ink fountain roller

3rd

Support roller

4th

hanger

5

Cam roller

6

Cam roller

7

hanger

8th

Cam roller

9

suspension

10th

Color metering element

11

frame

12th

Runway

13

attack

14

Ink fountain roller

15

Paint box

16

Support rail

17th

Swivel bearing

18th

traverse

19th

Ink box side wall

20th

hanger

21

Cable entry

22

axis

23

Cam roller

24th

axis

25th

Cam roller

26

Swivel bracket

27

axis

28

Cam roller

29

axis

30th

Spring support

31

Disc spring package

32

Pivot point

33

Unlocking element

34

axis

35

Handle

36

Rubber buffer

37

renewal

38

Locking hole

39

Paint collecting tray

40

bracket

41

Lower part

42

Roller storage

43

Side frame

44

attack

45

Rubber buffer

46

Cable entry

47

Drip tray

48

Bearing element

49

Bearing element

50

Support surface

51

Trestle

52

Set screw

53

Cover plate

Claims (13)

1. Device for guiding an ink fountain with metering elements against an ink fountain roller, wherein the ink fountain lies on a part fixed to the frame with elements which, at both ends of the ink fountain roller, generate holding forces between ink fountain roller and ink fountain, and operating elements engaging on these, characterised in that firmly connected with the ink fountain (1, 15) are arranged first (5, 23) and second guide elements (6, 25) in the plane of the metering elements (10) or in or near an exact vertical diametral plane against the upper side of the ink fountain roller (2, 14), and that third guide elements (8, 28) are arranged swivellably on the ink fountain (1, 15) which are themselves connected with the elements (9, 30, 33) to generate the holding forces while supporting themselves against the ink fountain (1, 15) itself, wherein the first (5, 23) and third guide elements (8, 28) with inclusion of the second guide elements (6, 25) in each case enclose an angle of at least 180°.
2. Device according to Claim 1, characterised in that the ink fountain (1) lies guided on both sides of the support rolls (3) on roller tracks (12) fixed to the frame and accordingly on four points on the guide elements (5, 6, 8) and the support rolls (3), that the roller tracks (12) are provided on the ends remote from the ink fountain roller (2) with stops (13) and that for operation, a lever drive is provided which is so supported between press frame (11) and ink fountain (1) that the ink fountain (1) for tipping away from the ink fountain roller (2) is positively guided around the axis of the support rolls (3) lying against the stops (13).
3. Device according to Claim 1, characterised in that the ink fountain (15) is provided on its underside with a support rail (16) and the support rail (16) provided centrally with a slightly higher lying support surface (50), that a cross member (18) fixed with respect to the frame is provided with at least one bearing element (49) on which the ink fountain (15) rests by means of the support surface (50), and that for operation, lever drives (30, 33) are provided which connect the ink fountain (15) with the third guide elements (28) and which can be locked to the ink fountain (15).
4. Device according to Claim 3, characterised in that the support surface (50) is raised only slightly, e.g. by 0.3-0.5 mm above the edge of the support rail (16) and is slightly broader than the bearing element (49).
5. Device according to Claim 3 and 4, characterised in that on both sides arcuate bows (20) are connected with the ink fountain (15), that cam rolls (23, 25) are provided on the bows (20) as guide elements, that at the upper end of each pair of bows (20) there is provided in each case a swinging bow (26) on the axle (24) of the cam roll (25) arranged there, that at one end of each swinging bow (26) there is provided a further cam roll (28) as a third guide element and engages at the other end the lever drive.
6. Device according to Claim 3 and 4, characterised in that each lever drive consists of an unlocking element (33) arranged swivellably on the bow (20), with handle (35) arranged on this and a spring support (30), wherein the latter is pivotally connected with the unlocking element (33) and the swivel bow (26).
7. Device according to Claims 3 to 6, characterised in that the handle (35) is slidable in the unlocking element (33) against spring force and is provided with a prolongation (37), and that in a component connected with the bow (20), a locking bore (38) is provided in which the prolongation (37) of the lever drive engages in unlocked condition.
8. Device according to Claims 3 to 7, characterised in that damping elements (36, 45) are provided between ink fountain (15) and ink fountain roller (14) as well as between ink fountain (15) and side frame (43).
9. Device according to Claim 8, characterised in that on each unlocking element (33) a rubber buffer (36) is provided in such a fashion that this, on swinging on of the ink fountain (15) with the handle (35) engaged, meets the ink fountain roller (14) prior to the cam roll (23) and on locking on excess pressure of the lever drive is swung away from the surface of the ink fountain roller (14) and that further rubber buffers (45) fixed to the frame are provided which cooperate on swinging away with stops on the ink fountain (15).
10. Device according to Claim 9, characterised in that the additional rubber buffers (44) on the side frame (43) are mounted and that prolongations (44) of the axles (22) of the cam rolls (23) in the plane of the ink metering elements (10) serve as stops.
11. Device according to Claim 3 and 4, characterised in that in the cross member (18), three bearing elements (48, 49) are provided, wherein the central (49) is arranged relative to the guide surface (50) on the support rail (16) and carries the respective swivel bearing (17) and both the outer are provided with identical swivel bearings, but which are arranged behind the edge of the support rail (16) inclined back behind the guide plane (50), that the bearing elements (48, 49) are arranged symmetrically relative to the cross member (18) and that on both sides of the outer bearing elements (48) adjustment blocks (51) are provided, in which adjusting screws (52) are arranged for axial positioning of the ink fountain (15) against side surfaces of the support rail (16).
12. Device according to Claim 3 and 4, characterised in that the support surface (50) on the central bearing element (49 is height adjustable.
13. Device according to Claim 8, characterised in that as damping element between ink fountain (15) and side frame (43) a shock absorber is provided which, in each case, is pivotally connected with the ink fountain (15) and the side frame (43).

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