APPARATUS FOR THE ALTERNATIVE CLEANING OF TWO ADJACENT CYLINDERS IN A PRINTING PRESS, WITH A SINGLE CLEANING DEVICE

Abstract: The shoulders (F, F') of the cleaning device (B, P, T, R1, R2) are hinged to connecting rods (3, 3') rotating on a real or virtual pivot axis (A, A', 33) situated between the cylinders to be cleaned (C1, C2) and parallel to these, the said connecting rods being interconnected by torsion means. At least one of the said shoulders (F') is provided with a rear wheel (8) which runs in a fixed guide (9) situated approximately at the same height as the said pivot axis and approximately perpendicular to it. Means (14, 20, 25, 28) are provided for pivoting the said connecting rods, in such a way that because of the presence of the said guide (9) the cleaning device executes a simultaneous movement of rotation upon itself and about the said pivot axis (A, A', 33), in order to act on one of the cylinders to be cleaned or to park in a position away from these, useful as a position of rest or of maintenance of the apparatus. On at least one of the shoulders of the cleaning device is at least one wheel (22) that can interfere with cams (D) fixed to the side of one of the cylinders to be cleaned if the latter is provided with gripping clamps (Z) or other irregularities of its surface, in order automatically to prevent undesired interference of the cleaning device with critical areas of the said cylinder that is to be cleaned.

Description: TITLE: Apparatus for the alternative cleaning of two adjacent cylinders in a printing press, with a single cleaning device. DESCRIPTION The invention relates to reel- or sheet-fed rotary printing presses with parallel cylinders which in the course of operation become wetted with ink and fouled with particles of paper and must therefore be cleaned periodically. Known cleaning devices for this purpose comprise, for example, a light alloy bar parallel to the cylinder to be cleaned. This is usually fixed and its face turned towards the cylinder usually incorporates a longitudinal straight recess through which is guided a presser with a flexible elastic membrane close to the cylinder. The same bar contains pneumatic actuators which on command press the presser against the cylinder so as to contact it with an interposed cloth on which washing fluids are sprayed by nozzles mounted in seats let into the face of the bar which is nearest the cloth. The cleaning cloth is unwound from a feed roller and its other end is connected to a winding roller and both these rollers, together with their means of rotation, are mounted on parallel shoulders supporting the said bar. Also known are cleaning devices that differ from the above and comprise a brush designed to contact the cylinder to be cleaned and sprinkled by nozzles with the cleaning fluid. In the remainder of the description the expression "cleaning device" will be used to denote any device for cleaning the cylinders of a printing press, even if different from the devices indicated above. In the prior art, each printing cylinder that has to be cleaned is normally provided with its own printing device. This solution is rather expensive and reduces the amount of space available for inspecting the cylinders of the printing press. To solve these problems, because the cylinders that are to be cleaned are often close together, for example the impression cylinder and the blanket cylinder, it is also known practice to use a single device for the alternative cleaning of one or other of the two cylinders and for this purpose this device is mounted on suitable drive systems. In some printing presses, such as those of the type produced by the Japanese company Komori, there is a functional shaft running parallel between the two abovementioned cylinders which makes it impossible to use conventional transfer systems for transferring the cleaning device from one roller to the other. The invention aims to solve this technical problem with an apparatus for transferring the cleaning device which is technically reliable, of moderate cost, and in which the cleaning device can be installed and removed quickly and simply on and off its supporting means. The device according to the invention can be fitted both to presses that do have this functional shaft between the cylinders that are to be cleaned, and to those presses which originally have no such functional shaft and which because of the presence of gripping clamps on one of the cylinders can usefully employ the present apparatus, which is characterized by among other things the fact that it can automatically prevent interferences between the cleaning device and the said clamps. The features of such an apparatus and the advantages which result therefrom will be clear from the following description of certain preferred embodiments, illustrated purely by way of non-restrictive examples, in the figures of the attached sheets of drawings, in which: - Figs. 1 , 2 and 3 illustrate the present apparatus in side view, respectively in the position for cleaning the lower cylinder, in an intermediate position and in the position for cleaning the upper cylinder; - Fig. 4 illustrates other details of the apparatus partly sectioned on IV-IV as marked in Figure 2; - and Figs. 5, 6 and 7 illustrate variants of the apparatus, the first two in side view and the last in perspective. In the figures, C1 is the blanket cylinder, C2 the impression cylinder, C3 the transfer cylinder and A is the functional shaft which in some machines is situated parallel between the cylinders C1 and C2. The apparatus under consideration pivots about the shaft A and, in a preferred embodiment, uses this shaft as a fulcrum. Mounted rotatably by their big ends on the ends of shaft A are mutually aligned connecting rods 3, 3', made for example from a suitable material with a low coefficient of friction, to which the ends of a steel half tube 1 is fixed coaxially with the same shaft A but not touching it, the only function of the half tube being to connect the connecting rods structurally to each other, so that if one of them is pivoted, this pivoting is transmitted simultaneously to the other connecting rod. The rods 3, 3' may be made for example from a bronze alloy plate and they comprise an arcuate head piece 2, 2' and a shank 102, 102' whose forked end bears on the shaft A together with the said head piece 2, 2' and the ends of these two parts partially overlap and are fixed together and to the half tube 1 by means of screws 4, 4'. The half tube 1 may for example be located on the same side as the head pieces of the rods 3, 3'. Hereinbelow, with reference to Figure 5, a variant will be described of the connecting rods and of their means of interconnection. 5, 5' indicate the stop screws fixed perpendicularly to the outside flanks of the connecting rods 3, 3' and acting on the shoulders S, S' of the printing press in order to ensure that the assembly 1 , 3, 3' suffers no undesirable axial movements. Figures 1 and 4 illustrate the cleaning device mounted on the present apparatus and, by way of example, it comprises a bar B that supports the presser P and that carries the complex of nozzles for dispensing the washing fluid onto the cloth T which travels around the complex B, P, being unwound by suitable means from the roller R1 and wound back onto the roller R2. These rollers and the said bar B are all supported by the shoulders F, F' which in turn are hinged to the little ends of the connecting rods 3, 3' by pins 6, 6', of which more later. It will be understood that any other cleaning device, wholly or partly different from that considered above, may be mounted on the shoulders F, F'. On the rear end of one of the shoulders F, F', for example shoulder F, is a protrusion 7 on the side of which is a wheel 8 which runs in a guide channel 9: the latter is roughly perpendicular to the shaft A and to the various surfaces to be cleaned, is approximately horizontal or suitably inclined and is formed in a plate 10 fixed by the distance pieces 110 to the nearest shoulder S of the printing press. The plate 10 may for example be at approximately the same height as the shaft A. The distance between the imaginary hinge axis formed by the pins 6, 6' and the nearest point on the circumference of the shaft A needs to be greater than the distance between the same imaginary axis and the adjacent upper and lower forward part of the complex B, F, F' in order that this complex can when required rotate about itself and about its shaft A, while keeping its forward face always oriented towards the cylinders C1 , C2 and without interfering with the said shaft (see later). In Figure 4 it can be seen for example that the pins 6, 6' can be moved axially within their blind seats 11 , 11 ' which are formed in the complex F, F', B, B', together with springs 12, 12' which push the pins outwards against the connecting rods 3, 3' where their narrow ends 106, 106' pass into holes formed in the little end of these connecting rods 3, 3'. By pushing the pins 6, 6' into the seats 12, 12' with a pointed tool, and moving the cleaning device in such a way that the wheel 8 comes out of the guide 9, the cleaning device can be removed quickly from its supporting means. Whereas the narrow end of pin 6 fits into a hole directly in the little end of the connecting rod 3, the end of pin 6' engages in the axial cavity of a screw 13 fastened to the little end of the rod 3', to the projecting portion of which is anchored the end of the rod of a double-acting primary jack 14 (operated by fluid pressure or electromechanically), whose body is attached to a pin 15 fixed to the adjacent shoulder S' of the printing press, for example approximately at the same height as the shaft A. It is understood that the axial mobility of the pins 6, 6' may be provided by a different solution to that described, e.g. by using screws for the pins. The present apparatus is completed by a lever 16 pivoting on a pin 17 fixed to the flank S of the printing press at approximately the same height as the shaft A and beneath the plate 10. This lever points towards the shaft A and on its free end has a wheel 18 and is hinged at an intermediate point 19 to the rod of a small secondary double-acting jack 20 (operated in a similar way to the said primary jack) which is hinged by its body to a pin 21 fixed to the said shoulder S. When the jack 20 has its rod retracted as in Figure 2, the wheel 18 is on the outside of the orbit which can be followed by a protrusion 103 that extends the connecting rod 3 beyond its little end. The operation of the apparatus as described is simple and obvious. When the apparatus is in position to clean the lower cylinder C2, the connecting rods 3, 3' are pointing down, the rod of the primary jack 14 is extended and the bar B is a short distance from the cylinder C2, this last condition being ensured for example by the force of the jack 14 and by the abutment of any part of the apparatus against a suitable stop means, for example by the abutment of the wheel 8 against a blind end 109 of the guide 9 or by the abutment of the connecting rods 3, 3' against end-of-stroke stops (not illustrated). The actuators mounted on the bar B and linked to the presser P, will provide the necessary interference between the cloth T, pushed by this presser, and the cylinder C2. To prevent interference between the cleaning cloth and any clamps Z on the cylinder C2, one side of the complex B, P is provided with a wheel 22 projecting the correct amount from the forward face of this complex and acted upon by cams of known type D fixed laterally with respect to the area of the cylinder C2 where said clamps are situated, so as to retract the said complex sufficiently to automatically achieve the abovementioned condition of non-interference. When the apparatus is to be prepared for cleaning the cylinder C1 , the primary jack 14 is retracted as in Figure 2. The cleaning device rises and simultaneously rotates about the shaft A and upon itself, about the axes 6, 6'. When a sensor (not shown) detects that the jack 14 has reached the end of its retraction stroke, e.g. a magnetic sensor which detects the position of the piston of the jack, the rod of the secondary jack 20 is extended. This causes upward pivoting of the lever 16 with the wheel 18 which interferes with the protrusion 103 on the connecting rod 3 and lifts the hinge axes 6, 6' of the apparatus above the point of dead centre which is defined by the previous withdrawal of the primary jack 14, which latter at the correct moment is extended to complete the raising of the cleaning device and the positioning of the bar B a short distance from the cylinder C1 , as in Figure 3. After performing its short lifting stroke, the secondary jack 20 can be retracted in order to return the wheel 18 to the down or rest position, or alternatively this wheel can be left in the up position, out of the orbit of interference with the protrusion 103 of the connecting rod 3 (see later). In this case, too, the cleaning device is secured in the correct position relative to the cylinder C1 to be cleaned, by the force of the primary jack 14 and by the abutment of any of the parts of the apparatus against suitable stop means, e.g. by abutment of the wheel 8 against the blind end 109 of the guide 9 or by abutment of one of the connecting rods against a barrier (not shown). When the apparatus is not being used and/or when the cleaning device is in need of maintenance and must be removed, the apparatus is, for example, in the intermediate position shown in Figure 2 and safety means can be provided to lock the apparatus mechanically in this position. Safety means may also be provided to lock the cleaning device mechanically adjacent to the cylinders that are to be cleaned, provided these have no gripping clamps or other irregularities on the round surface. The return of the apparatus to the down position for cleaning of the cylinder C2 may not require operation of the secondary jack 20, as the weight of the complex B, P on the connecting rods 3, 3' should be sufficient to ensure that the latter rods have no difficulty getting past the dead centre, while the primary jack 14 moves automatically from the retraction phase to the extension phase. It would be understood, however, that should the weight of the apparatus be insufficient to overcome the friction of the fulcrums and hinges, so that gravity is unable to move the apparatus past the position shown in Figure 2, this job can be done by the secondary jack 20 which will be kept extended when the apparatus is in the raised position and will be retracted when the apparatus is in the position of Figure 2, so that the wheel 8 interferes from the top down with the protrusion 103 of the connecting rod 3 and pushes the complex below horizontal dead centre. Reference to Figure 5 will show that in a possible variant the connecting rods 3, 3' may be identical and made of steel, with an internal radius of curvature of parts 2, 102, 2', 102' greater than the radius of the shaft A, these parts of the connecting rods being fitted with three rotatable wheels 23 whose axes are parallel to the said shaft A and that bear on this shaft to enable the connecting rods to pivot with rolling friction. The same Figure 5 shows that the connecting rods 3, 3' may be connected in a different way by a pair of parallel beams 24, 24' fastened to the connecting rods by the pairs of screws 4, 4' which enable fastening together of the parts 2, 102, 2', 102' of which the rods are composed. In another variant illustrated in Figure 5, the connecting rods 3, 3' are pivoted by means different from the jacks 14, 20 discussed previously. A sector gear 25 is fixed to the outside of one of the connecting rods and meshes tangentially with a rack 26 which is kept on this gear 25 by an idle wheel 27 and attached to the rod of a jack 28, which in turn is flanged to a support 29 fixed at 30 to a plate 10' attached to the adjacent shoulder S of the printing press. Means (not shown) are provided so that the jack 28 can be actuated with an intermediate stroke which places the cleaning bar B in a position remote from both cylinders C1 , C2, which is useful for various operations of maintenance of the apparatus. The apparatus according to the invention can also be fitted to printing presses that do not have the functional shaft A discussed previously. In this case the machine can be fitted with such a shaft A', preferably mounting it on the shoulders S, S' with intermediate supports 31 with bearings, as in Figure 7 and using monolithic connecting rods 3, 3' which are keyed to the shaft by means of a set screw 32 or by other suitable means. Figure 6 illustrates another alternative construction in which the connecting rods can be keyed to a synchronizing shaft A', or can be hinged at one end to the shoulders of the press, as indicated for example at 33 in Figure 6, in such a way that the apparatus is able to rotate about an axis, parallel to the rollers to be cleaned, that is no longer physical as in the previous cases, but virtual. In this case use will be made of means for accurately synchronizing the pivoting of the connecting rods 3, 3', e.g. by using a synchronizing shaft 34 supported rotatably by the connecting rods and fitted at its end with pinions 35 meshing with sector gears 36, the latter being concentric with the axes of rotation 33 and fixed to the shoulders S, S' of the press. 37 denotes one of the connecting rod operating jacks. In the example shown in Figure 6, the shaft 34 is fixed to the flanks F, F' of the cleaning device and if the sector gears 36 have external teeth, as indicated in solid lines, during the pivoting of the connecting rods the cleaning device rotates with its working face on the orbit 38, which is the opposite of the orbit followed in the previous cases. The cleaning device can rotate on the same orbit as in the previous cases, if the sector gears 36' have internal teeth as partly illustrated in broken lines in the same Figure 6. It is understood that the interconnection provided by the shaft 34 may be achieved otherwise by the frame F, F', B only of the cleaning device, as this also is a rigid element. It will be understood that the scope of the invention also encompasses other ways of rotating the cleaning device about a virtual axis parallel to the cylinders to be cleaned, such as with the same cleaning device supported rotatably at either end by carriages with wheels running on fixed arcuate guides whose centre of curvature is on the said virtual axis.

Claims: CLAIMS 1. Apparatus for the alternative cleaning of two adjacent parallel cylinders (C1 , C2) in a printing press, with any suitable type of cleaning device (R1 , R2, B, P, T) having for example a pair of shoulders (F, F') located on the inside of and a short distance from the shoulders (S, S') of the printing press, which apparatus is characterized in that it comprises cleaning device support means (3, 3') that enable the cleaning device to describe on command a rotational or pivoting movement about a real or virtual axis (A, A') parallel to and between the cylinders to be cleaned, and in that it comprises means such that the same cleaning device executes a simultaneous rotational or pivoting movement about its own longitudinal axis which passes through the points of connection of the said support means, in such a way that the cleaning device is able to move from a position in which its working face is towards the lower cylinder (C2), to a position in which its working face is towards the upper cylinder (C1 ), or vice versa, with a parking position alongside either of these cylinders or in an intermediate position of rest or of maintenance. 2. Apparatus according to Claim 1 , characterized in that the shoulders (F, F') of the cleaning device are hinged on their outward faces to parallel connecting rods (3, 3') whose little ends pivot on a real or virtual axis (A, A') parallel to and between the cylinders to be cleaned (C1 , C2), means being provided for pivoting these connecting rods in a synchronized manner and means being provided for rotating the cleaning device about the supporting hinges (6, 6') by means of the said connecting rods, in such a way that the cleaning device positions its working face against the said cylinders to be cleaned or locks itself in an intermediate position of rest or of maintenance. 3. Apparatus according to Claim 1 , in which the connecting rods (3, 3') use as their pivot axis a shaft (A) arranged parallel to and between the cylinders that are to be cleaned, which shaft may be functional and intrinsic to the printing press or may be added, for example by attachment to the shoulders of the said press, the connecting rods being mounted rotatably on this shaft and being interconnected by torsion means (1 , 24) which cause them to act together in the pivoting movement. 4. Apparatus according to Claim 3, characterized in that the connecting rods (3, 3') may each be made in at least two parts (2, 102, 2', 102') for collar-type assembly around the pivoting shaft (A, A'), it being preferably for the screws (4, 4') for the fixing together of the two connecting rod pieces to be able to be used to fix the said connecting rods to the ends of the torsion means (1 , 24). 5. Apparatus according to Claim 3, in which the connecting rods (3, 3') are made from a material with a low coefficient of friction and pivot in contact with the said shaft (A). 6. Apparatus according to Claim 2, in which the connecting rods (3, 3') are made of steel and are mounted rotatably on the said shaft (A) with intermediate wheels (23) fixed rotatably to and projecting from one side of the said connecting rods. 7. Apparatus according to claim 3, in which the torsion means that connect together the connecting rods (3, 3') consists of a half tube (1 ) arranged parallel to and concentrically about the shaft (A) on which the said connecting rods pivot. 8. Apparatus according to Claim 2, characterized in that the torsion means that connects together the connecting rods (3, 3') consists of one or of a pair of beams (24) parallel to each other and to the said connecting rod support shaft (A). 9. Apparatus according to Claim 2, characterized in that if the printing press has no functional shaft (A) between the cylinders that are to be cleaned, supports (31 ) are fitted to the shoulders (S, S') of the press for the rotary support of the ends of such a shaft (A') to which the connecting rods (3, 3') of this apparatus are fixed. 10. Apparatus according to Claim 1 , in which at least one of the shoulders (F) of the cleaning device (B, P, T, R1 , R2) carries at its rear and to the side a wheel (8) which runs in a guide channel (9) situated approximately at the same height as the shaft (A, A') that supports the apparatus, approximately perpendicular to this shaft and formed for example in a plate fixed to the adjacent shoulder (S) of the printing press, the whole arrangement being such that as a result of the pivoting of the connecting rods (3, 3') on which the cleaning device is supported, the cleaning device moves from the position of perpendicularity to one of the cylinders to be cleaned to a position of perpendicularity to the other cylinder to be cleaned, with a pivoting movement also about the said rear wheel (8). 11. Apparatus according to Claim 10, characterized in that there is hinged to the opposite shoulder (S') of the press from that carrying the plate (10) with the said guide channel (9), for example approximately at the same height as the shaft (A, A') positioned between the cylinders that are to be cleaned, the body of a primary jack (14), operated by means of pressurized fluid or electromechanically, and double-acting, whose rod is hinged to the same little end of the adjacent connecting rod (3') as one side of the cleaning device is hinged to, in order to keep this device in the working position alongside the lower cylinder (C2) or alongside the upper cylinder (C1 ), the little end of the opposite connecting rod (3) having a protrusion (103) which continues beyond the axis (6) whereby it is hinged to the cleaning device and which, when the rod of the said jack (14) is retracted, with the cleaning device approximately equidistant from the cylinders (C1 , C2), is situated on the orbit that can be followed by the wheel (18) on the end of a lever (16) pivoting on the shoulder (S) of the printing press and hinged (19) to the normally retracted rod of a secondary 0 jack (20) which is activated when the cleaning device is to be raised from the said position of equidistance from the cylinders in order to act on the upper cylinder (C1 ), because by this activation the wheel (18) of the said lever interferes with the said protrusion (103) on the end of the connecting rod (3) and can raise it past the dead centre, while the primary jack acts in phase in order to push the cleaning device 5 towards the upper cylinder. 12. Apparatus according to Claim 11 , characterized in that the secondary jack (20) can be used actively to take the apparatus past the point of dead centre caused by the activation of the primary jack, even when the cleaning device is to be transferred from the upper cylinder to the lower cylinder, in order for example to o overcome any friction in the pivot fulcrums of the said apparatus. 13. Apparatus according to Claim 2, characterized in that the connecting rods (3, 3') are caused to pivot by a pinion-and-rack system (25, 26) which acts on one of the said connecting rods, the rack being actuated by a double-acting jack (28). 14. Apparatus according to Claim 2, characterized in that the connecting rods are hinged about spindles (33) supported rotatably by the adjacent shoulders (S, S') of the printing press and lined up on a common virtual axis parallel to the cylinders that are to be cleaned, the shoulders (F, F') of the cleaning device being fixed to a shaft (34) parallel to the said virtual axis, which is supported rotatably by the connecting rods (3, 3') and which carries, fixed to its ends, pinions of equal diameter (35) or equivalent means which mesh directly or indirectly through positive drives with fixed toothed annuli (36, 36'), concentric with the said virtual axis, so that when the connecting rods (3, 3') are pivoted by a jack (37), the cleaning device pivots about itself, either passing or not passing through the said virtual axis, in order to locate itself with the necessary perpendicularity relative to the cylinder that is to be cleaned. 15. Apparatus according to Claim 1 , having means for stopping the connecting rods (3, 3') rotating when the cleaning device is alongside one of the cylinders that are to be cleaned, in order that the cleaning device is stopped in a position of non-interference with the cylinder, against which the active member (P, T) of this device is pushed by its own means. 16. Apparatus according to Claim 1 , characterized in that on one of the shoulders (F, F') of the cleaning device, at the forward face of this device, is a wheel (22) that can be acted upon by cams (D) of known type mounted on the side of one of the cylinders to be cleaned (C2), for example by the impression cylinder, where there are gripping clamps (Z) on this cylinder, in order to move this same cylinder automatically away from the cleaning device when the latter would interfere with the said clamps, in order to avoid such interference, whereas when the clamp has been passed, the elastic action of the pivoting means of the connecting rods (3, 3') of the apparatus causes the cleaning device to return automatically to the working position on the cylinder that is being cleaned. 17. Apparatus according to Claim 3, characterized in that when the connecting rods (3, 3') are mounted rotatably on a supporting shaft (A), adjustable stops are preferably provided on the outside flanks of these connecting rods to act on the adjacent shoulders (S, S') of the press in order to prevent undesirable axial movements of the apparatus. 18. Apparatus according to Claim 2, in which the pins (6, 6') by which the shoulders (F, F') of the cleaning device are hinged to the connecting rods (3, 3') are mounted on the said shoulders in a removable condition, in order to permit quick, simplified assembly and disassembly of the cleaning device to and from its supporting means.

Inventors: CORTI MARCO, FUMAGALLI RICCARDO, CORTI, MARCO, FUMAGALLI, RICCARDO
Applicants: CORTI MARCO, FUMAGALLI RICCARDO, CORTI, MARCO, FUMAGALLI, RICCARDO
Application year: 1999
Main classification: B41F35
IPC codes: B41F35