FUMAGALLI, Riccardo (Via Baravico 41, Oggiono, I-23848, IT)
CORTI, Marco (Via Fornaci 16, Lecco, I-23900, IT)
FUMAGALLI, Riccardo (Via Baravico 41, Oggiono, I-23848, IT)
CLAIMS
1 ) Device particularly suitable for cleaning idler rolls (1 ) of paper webs (C) in rotary printing presses, characterized in that it comprises, under each cleaning roller and parallel thereto, at least one bar (4) whose nozzles (104) spray liquid solvent on command, the spray being sufficiently distributed at least on the portion of the paper web (C) which is about to come into contact with the cleaning roller, and which, during the cleaning of the latter, is made to advance in the same direction of operation, but at limited speed, and also characterized in that it comprises means which are activated, in the same cleaning phase, to cause the independent rotation of the cleaning roller, thus making it rub against the paper web carrying the solvent and progressively bringing it into contact with this web over its whole surface, so that the dirt is removed by the said paper web treated with solvent, these latter means being preferably such that they transmit to the cleaning roller a rotation in the opposite directionto the direction of advance of the paper web carrying the solvent. 2) Device according to Claim 1 , in which the said means which are activated on command to cause the cleaning roller to rotate and rub against the paper carrying the solvent are such that they act on at least one end portion of the cleaning roller, which is clean because it is not normally in contact with the paper web (C). 3) Device according to Claim 2, in which the said means which is brought, on command, into contact with at least one end of the cleaning roller (1 ) to transmit thereto a rotation independent of the paper web is formed by at least one roller (8), preferably rubber-coated and with its axis parallel to that of the cleaning roller, or an equivalent means, which is moved by suitable means from a rest positionto a position of contact with the end of the cleaning roller. 4) Device according to Claim 3, in which the said rubber-coated roller (8) is mounted on a lever (7) which a linear actuator (10) can cause to oscillate on its fulcrum (6) to move the said roller (8) from a remote rest positionto a position of contact with the end of the cleaning roller (1 ), the said actuator preferably being formed by a cylinder and piston unit of the pneumatic type, by means of which the said roller can be made to contact the cleaning roller with the correct pressure. 5) Device according to Claim 4, in which the shaft or the end of the said rubber- coated roller (8) is mounted on the oscillating support lever (7) and interacts with the end of an operating lever (12), with the interposition of free wheels (1 1 ) such that, when the rubber-coated roller is brought into contact with the cleaning roller (1 ), the latter stops, while when the said operating lever (12) is made to oscillate cyclically by a corresponding linear actuator (14) formed for example by a pneumatic cylinder, the rubber-coated roller, together with the cleaning roller, is made to rotate intermittently and still in the same direction which is preferably opposite to the direction of advance of the paper web carrying the solvent (C). 6) Device according to claim 1 , characterized in that it comprises a pair of supports (2), which are fixed with screw clamps (102) to the ends of the shaft (101 ) on which the cleaning roller (1 ) rotates idly, and which project away from the paper web (C) in an L-shape so that their bases support brackets (3) for supporting the ends of the said bar (4) carrying the cleaning liquid delivery nozzles, the base of one of these supports (2) also being made to support the fulcrum (6) of the oscillating lever (7) which carries the said rubber-coated roller (8) or an equivalent means.
7) Device according to claim 4, characterized in that the said oscillating lever (7) for supporting the said rubber-coated roller (8) carries an arm (107) fixed at a right angle on the end opposite the fulcrum, with the ends of the said linear actuators (10, 14) pivoted on this arm, the rods of the actuators being pivoted respectively on the upper part of the said support (2) and on the said operating lever (12).
8) Device according to Claim 1 , in which a suitable casing (5) is provided above the bar (4) for delivering the cleaning liquid to the paper web (C), this casing preventing or limiting the bar's direct wetting of the lower surface of the cleaning roller (1 ) located above it.
9) Device according to claim 4, in which terminal appendages (115) of a small casing (15) are fixed to the support (2) which supports the said oscillating lever (7) carrying the rubber-coated roller (8) or other equivalent means, this casing protecting this roller (8) and the corresponding contact area of the cleaning roller (1 ) for safety reasons. 10) Device according to claim 1 , characterized in that, since the cleaning liquid used for one cleaning roller can also be used for a sufficient number of successive cleaning rollers which can thus be provided solely with the independent movement equipment formed by the rubber-coated roller (8) and ratchet (1 1 -14) or other suitable equivalent means, and since the paper web (C) touches some of the successive cleaning rollers with the face opposite that which is sprayed with solvent by the said bar (4), the device can be provided with a second spray bar (4') opposite the aforesaid bar (4), to spray solvent additionally on the outer face of the paper web (C), also with a correct upward inclination, this outer bar (4') being supported at its ends by brackets (3') fixed to the bases of suitable attachments (202) of the said end supports (2).
1 1 ) Device according to Claim 10, characterized in that flat deflectors (105, 105') are fixed to the bodies of the opposing spray bars (4, 4') along their whole length, the longitudinal edges of these deflectors projecting to a position close to the paper web (C), so as to form, in combination, a double-pitched roof of a chamber such that, if a web (C) whose width is smaller than the nominal maximum width is used, end portions of the said chamber are in direct communication with each other and the said upper deflectors (105, 105') can collect the solvent sprayed by the end nozzles of the said bars (4, 4'), and this solvent is directed, by gutters (205, 205'), into collecting and discharge tanks (16, 16', 1 16, 1 16').
12) Device according to claim 1 , characterized in that it comprises sensors for indicating, at the end of the cleaning cycle, when the rollers or other means (8) for causing the cleaning rollers (1 ) to rotate have returned to the rest position, so that the rotary press can resume its operation in entirely safe conditions. |
TITLE: DEVICE FOR CLEANING THE IDLER ROLLS OF PAPER WEBS IN ROTARY PRINTING PRESSES
DESCRIPTION The invention relates to a device which is particularly suitable for the periodic cleaning of idler rolls of the continuous paper web in rotary printing presses, since these rolls, also called cleaning rollers, tend to become progressively dirtier. There is a known method of cleaning the cleaning rollers by spraying liquid on them to dissolve the dirt, which is removed by the continuous paper web which is kept moving during the cleaning phase. The solutions used at present have proved to be rather unreliable and complicated, and the invention therefore proposes a device for the periodic cleaning of the cleaning rollers which is easy to construct and easy to fit even to systems which are already operational, and which has a high degree of reliability in use.
The characteristics of the device in question are indicated in the attached Claim 1 and in the following dependent claims, and will be made clear by the following description of a preferred embodiment of the device, illustrated purely by way of non- limiting example in the figures on the three attached sheets of drawing, in which:
- Fig. 1 is a view in lateral elevation and in partial section of the device in the rest position;
- Figs. 2 and 3 show the device as shown in Figure 1 , but in two different positions of its operating cycle; - Fig. 4 is a perspective view from above of an end portion of the cleaning roller with a corresponding part of the device in question;
- Fig. 5 shows the device as shown in Figures 1 - 3, in an improved version;
- Fig. 6 is a perspective view of an end portion of the cleaning roller with a corresponding part of the device shown in Figure 5.
In Figures 1 and 4, the number 1 indicates the cleaning roller which rotates idly about its shaft 101 which is supported at its ends by supports which are not shown in the drawings. At the ends of this shaft 101 , flat supports 2 are fixed transversely, for example by a clamp fastening and with screws 102, and these supports project in an L-shape from the part of the hollow tube 1 which is not in contact with the paper web C which follows, for example, an ascending path, as indicated by the arrow F. On the base portions of the supports 2 there is fixed, by means of end brackets 3 (see below), a bar 4 with nozzles 104 which, on command, deliver atomized cleaning liquid which has the property of dissolving the dirt on the cleaning roller. The nozzles 104 are positioned at a precise distance from each other and are orientated so as to strike in a sufficiently distributed and uniform way a transverse portion of the face of the paper web C which is about to come into contact with the cleaning roller 1 and which is positioned immediately upstream of the cleaning roller. To prevent the cleaning liquid delivered by the nozzles 104 from being deposited directly and/or to an excessive extent on the lower surface of the cleaning roller 1 , a suitable casing 5 is provided above the bar 4 and parallel thereto, this casing being fixed to the bar 4 and/or to the said brackets 3.
A lever 7 is pivoted at 6 on the same base of one of the supports 2, this lever carrying in its intermediate part the shaft of a roller 8 which has a rubber-coated face parallel to the cleaning roller 1 , and the lever 7 carries an arm 107 fixed at a right angle to its upper end remote from the cleaning roller, with the body of a cylinder and piston unit 10, preferably of the pneumatic type, pivoted on this arm at 9, with its rod pointing towards the cleaning roller 1 and pivoted by this rod at 109 on the upper part of the support 2. By means of the piston 10, the rubber-coated roller 8 can be kept in the rest position of Figure 1 , away from the cleaning roller 1 which rotates freely as a result of the paper web C running on it, or the rubber-coated roller 8 can be brought into contact with the requisite degree of pressure with the cleaning roller 1 , thus stopping it, because the end or the shaft of this roller is connected for operation, with the interposition of opposing free wheels 11 , to the corresponding support lever 7
and to the end of an operating lever 12 whose other end is pivoted at 13 on the rod of a cylinder and piston unit 14, of the pneumatic type for example, which in turn has its body pivoted at 1 13 on the free end of the arm 107. Because of the presence of the said free wheels 1 1 , the lever 12 can be made to oscillate by the cylinder 14, and the rubber-coated roller 8 can transmit an intermittent rotationto the cleaning roller 1 , with a limited angular movement.
The device designed as above operates in the following way.
As stated above, when the rubber-coated roller 8 is at rest, as in Figure 1 , the bar 4 is inactive and the rubber-coated roller 8 is positioned away from the cleaning roller 1 which rotates, for example, in the clockwise direction, as a result of the paper web C which runs on it while travelling in the direction F. When the cleaning roller 1 has to be cleaned, the paper web C is made to advance, still in the direction F but at a lower speed than the printing speed, and the bar 4 is activated to deliver the cleaning liquid onto the portion of the web C which is about to run on the cleaning roller 1 , this liquid being spread uniformly on the web by gravity, thus preventing dangerous accumulations. The spraying of the liquid onto the web C can be continuous or pulsed, according to requirements (see below). In synchronization with the activation of the bar 4, the cylinder 10 is actuated so as to bring the rubber-coated roller 8 into contact with the cleaning roller 1 , to stop it, thus making the paper web carrying the solvent rub against the cleaning roll and clean it. In synchronization, the rod of the cylinder 14 is made to follow a cyclic path of extension and retraction, as shown in Figures 2 and 3, to transmit to the cleaning roller 1 small cyclic rotations about its axis, in such a way that the cleaning roller progressively presents different portions of its surface to make contact with the paper web C, which thus cleans the whole surface of the cleaning roller. The operating cycle can be timed or can be controlled by a programmer and by means which detect the cyclic movements of the lever 12, and deduces from these the cyclic rotation of the roller 8 and the rotation which this roller transmits to the cleaning roll 1. These means have not been illustrated, since persons skilled in the art will find them evident and easy to produce.
In a preferred embodiment of the invention, the ratchet system 1 1 and 12 described herein can transmit a cyclic rotationto the cleaning roller 1 in the anticlockwise direction as shown in Figures 2 and 3, with active rotation during the extension of the rod of the cylinder 14, as in the transition from Figure 1 to Figure 2, while in the reverse phase of retraction of this rod, as in the transition from Figure 2 to Figure 3, the ratchet absorbs the motion and the cleaning roller 1 does not rotate. In the cleaning phase, the cleaning roller 1 rotates in the anticlockwise direction, opposite to the direction of advance of the portion of web C with which it is in contact, causing the dirty surface of the cleaning roller to carry with it a small amount of the solvent sprayed by the bar 4 onto the web C, in such a way that, before coming back into contact with the web, this small amount of solvent has time to react with the dirt on the cleaning roller, so that when this dirt comes into contact with the web C it is in the best state for removal.
At the end of the cleaning cycle, the roller 8 is moved away from the cleaning roller 1 , the reciprocating movement of the cylinder 14 is halted, the bar 4 is turned off in synchronization, and the rotary press can return to normal operation.
The rubber-coated roller 8 acts on an end portion of the cleaning roller which is not in contact with the paper web C and therefore is not dirty; consequently the rubber- coated roller does not tend to gather dirt. The considerable simplicity of construction and high reliability in use of the described device is evident.
With reference to Figures 5 and 6, an improved design of the device will now be described, in which, among other features, terminal appendages 1 15 of a small casing 15 are fixed to the support 2 which supports the lever 7 carrying the oscillating roller 8, to protect the roller 8 and the corresponding contact area of the cleaning roller 1 for evident safety reasons.
In tests of the operation of the device it was found that the cleaning liquid used for a cleaning roller can also be used for a sufficient number of successive cleaning rollers, which can thus be provided solely with the independent movement equipment having a rubber-coated roller 8 and ratchet 1 1 -14. Since the paper web touches some of the successive cleaning rollers with its face opposite that which is sprayed with solvent by the said bar 4 described with reference to Figures 1 to 4, in the improved version of the device as shown in Figures 5 and 6 a second spray bar 4' is provided opposite the bar 4, to spray solvent additionally onto the outer face of the paper web C, again with the correct upward inclination. The bar 4' is, for example, supported at its ends by suitable brackets 3' fixed to the bases of L-shaped extensions 202 of the said end supports 2. The improved design described herein also serves to overcome a further technical problem, namely that of making the device usefully applicable in the case in which the rotary printing press sometimes uses paper webs with a width smaller than the nominal maximum width. If the device were designed for wider webs C, then, when narrower paper webs were used, corresponding end portions of the spray bars 4, 4' would be exposed and would disperse the solvent into the environment. To overcome this problem, flat deflectors 105, 105' are fixed to the bodies of the spray bars 4, 4' along their whole length, the longitudinal edges of these deflectors projecting to a position close to the paper web C, so as to form, in combination, a shape resembling a double-pitched roof over the chamber through which the web C passes. If a web C having a width less than the nominal maximum width is used (Fig. 6), end portions of the said chamber will be in direct communication with each other, and the said deflectors 105, 105' will collect the solvent delivered by the end nozzles of the bars 4, 4', and this solvent will be directed, by means of L-shaped gutters 205, 205', towards collecting tanks 16, 16' located under the said bars, and will be removed from these through corresponding discharge pipes 116, 1 16'.
It is to be understood that the description relates to a preferred embodiment of the invention, to which numerous variations and modifications may be made, particularly
as regards construction, which may for example relate to the fact that the rubber- coated roller 8 can be replaced with a small belt or conveyor, in such a way that the surface of this means contacting the cleaning roller is not restricted to a line but is wider and more distributed. The ratchet system as described can be replaced with other means for transmitting an intermittent or possibly continuous rotationto the rubber-coated roller 8 or to the equivalent means as stated above. The pneumatic cylinders 10 and 14 can be replaced with actuators of the electromechanical or other type. The tanks 16, 16' can be connected to air intake means, of low capacity, so as to prevent the dispersion into the environment of the odours of the solvent sprayed by the bars 4, 4'. Suitable sensors (not shown) can also be provided to indicate the return of the cleaning roller drive rollers to the rest position at the end of the cleaning cycle, so that the rotary press can resume its operation in entirely safe conditions.