US2096164A - Means for dispelling printing press mist - Google Patents

Description

Oct. 19, 1937. w. 'r. DIEFENBACH 2,096,164

MEANS FOR DISPELLING PRINTING PRESS, MIST Filed April 29, 1935 2 sheets-sheet 1 W/L L /AM 7.17/57 E/VBAC'H IN V EN TOR.

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A TTORNEY Oct. 19, 1937.

w. 'r. DIEFENBACH 2,096,164 MEANS FOR DISPELLING PRINTING PRESS MIST Filed April 29, 1935 2 Sheets-Sheet 2 INVENTOR.

M F RY M Fig 4 M Q A TTORNEY Patented Oct. 19, 1937 UNITED STATES PATENT OFFICE 2,096,164 MEANS FOR DISPELMLIIgrG PRINTING PRESS This invention relates to an ink mist precipitator or dispeller for printing presses for ameliorating, mitigating or controlling the flying or misting of ink, liquids or finely divided substances in printing or similar processes involving the transfer of such materials. 'This application is a continuation in part of my application Serial No. 741,180, filed August 23, 1934.

Some printing processes, especially the printing of newspapers where the speed of the press is relatively great, have been attended by a harmful andannoying phenomenon called ink flying or "ink misting. For reasons not understood up till now, ink from the press would distribute itself throughout the pressroom in such a fine mist that it was invisible. This mist would then blacken or make gray the walls or other objects with which it came into contact. This effect is not to be confused with ink thrown off by centrifugal force or spattered from various rollers or cylinders of the press, evidence of said spattering which occurs on or about the press generally in lines perpendicular to the axes of the printing rollers. Ink when it mists" spreads throughout the pressroom and is recognized by its effect of darkening objects at various points in the room even out of line with the printing" presses and at all points in the room.

in and about printing presses and has for many years been a source of complaint from both the tradesmen and operators of printing equipment. Numerous methods have been proposed for the prevention and elimination of this distressful condition in the publications of the printing fraternity but these have proven unsatisfactory.

After exhaustive studies on this phenomenon andon the structures of inks I have discovered the cause of ink mists and have created a means of controlling or dispelling them.

Although in the following discussion I shall speak of ink, other materials such as liquids, finely divided substances and films are also implied where they are pertinent.

As a result of my studies I have made the following discoveries:

In the printing process, films of ink or other material are transferred from rollers or cylinders to other rollers or cylinders, also to plates or plate cylinders and to paper, or other material in sheet or web form.

During this transfer not only is the ink transferred from one surface to another but also due to surface tension in the ink film, the cohesive property of the ink, and to other causes, the ink often gets drawn out into filaments or thin films between the inked surfaces as they move away from one another. A similar film is observed when the platinum ring of a Du Noy tensiometer is lifted from the surface of a printing ink.

This drawing out of ink into films or filaments occurs at various points on printing presses such as where the distributing rollers run in contact with the ink cylinders, or distributing drum where the plate inking rollers or form rollers run in contact with the ink cylinder where the form rollers run in contact with the plate cylinder and at other points.

As the contacting rollers or surfaces move further apart these films or filaments get drawn out thinner and thinner and finally shatter. This shattering gives rise to numerous very minute particles of ink in the vicinity of the moving rollers, cylinders or other parts involved.

These are the particles which go to form the ink mist and consequently this is a very important phase of my discovery, as I have found the actual source of the offensive mist particles.

The peripheral speeds of the press rollers or cylinders are not sufiiciently high to dissociate the ink particles by spattering or throwing to as high a degree as the dissociation observed in the phenomenon of ink misting. But the high press speeds very probably augment the attenuation of the film with subsequent increased fineness of the vision of the ink particles.

I have also discovered that these ink particles at the time of shattering become charged with electrical energy as a result of the shattering of the thin films or filaments. Particles acquiring charges of similar electric sign repel each other and this forms a mist or cloud which is readily carried about the pressroom, and elsewhere by air currents. Later these particles coming into contact with the various surfaces in the pressroom separate from the mist or fog onto the said surfaces and cause smutting or dirtying either by losing their electrical charge, or otherwise.

Now, in view of the foregoing, my invention relates to a means for eliminating, ameliorating or mitigating the spread of these ink particles by applying in combination with a printing press, a means for destroying the mist or fog as close as possible to the point of its emanation in said printing press.

To accomplish this, I have devised an embodiment of means comprising a cylindrical copper tube made of copper mesh of such a diameter as to fit between rollers or cylinders or other places where these attenuated films or filaments, which later shatter giving rise to the electrically charged mist particles develop, as for example between the form rollers and the plate cylinders, said cylindrical copper tubes to be in close proximity to their point of contact, yet not touching either. v

Also I have devised a means of supporting this cylinder in this location in such a way that it is free to rotate about its axis, said axis to be represented by a stationary hollow tube extending through the end of the framework of the printing press. The tube is so mounted in the framework as to be electrically insulated from it, that is to say, the tube is not in electrical contact with said frame ends. The cylindrical copper mesh is rotatably or permanently mounted on said hollow tube or shaft in electrical contact with it at all times.

Now I propose to develop on this shaft and on the said wire mesh attached to it an electrical charge of a given polarity or sign, which polarity or sign is opposite to that which is developed on 'the ink particles at the time of and due to the rupture or shattering of the films or filaments of ink. By this means the ink particles are attached to and deposited on the wire mesh and the charge on the mist or fog" is destroyed or neutralized.

Also by this means the ink mist or fog is destroyed at the point of its emanation and not leaving the improved machine as a mist or fog cannot circulate about the pressroom or vicinity to cause smutting or dirtying of surfaces with which it might have come into contact.

The ink which will be deposited on the charged wire mesh cylinder during a run will not-be of a very large quantity. In machines of some design no provision for wiping or cleaning is necessary as the ink if it does drip from the collecting mesh cylinder will only fall on the distributing rollers or the distributing drum which is sometimes also called the ink cylinder.

For cleaning, the wire mesh with its supporting shaft can be easily removed from the press and wiped or otherwise cleaned. If desired, means can be provided for removing the collected ink from the wire mesh cylinder while it is mounted in the printing press and for removing the collected ink through the hollow shaft or axial tube supporting the said wire mesh cylinder. In this I arrangement the hollow axial supporting shaft would have a slot on its upper side throughout its length. Attached to the axial tube or shaft at the upper side and extending upward to contact the wire ink collecting cylinder there would be a felt wiper. Means would then be provided to rotate the wire ink collecting cylinder about the shaft so that the felt wiper would remove the ink, causing it to flow down into the hollow axial supporting tube from which it could be removed from either side of the press frame.

With the above and other objects in view, the invention will be hereinafter more particularly described, and the combination and arrangement of parts will be shown in the accompanying drawings and pointed out in the claims which form part of this specification.

Reference will now be had to the drawings, wherein like numerals of reference designate corresponding parts throughout the several views, in which:

Figure l is a fragmentary view of a printing press showing an embodiment of the invention applied thereto.

Figure 2 is a fragmentary sectional elevation of aoeaiea the printing press with the mist dispelling embodiment partlyin section.

Figure 3 'is a cross-sectional view, the section being taken as on line 3-3 in Figure 2.

Figure 4 is a side view, diagrammatic in part, showing a newspaper printing press having two printing couples arranged in substantially horizontal position and having a modified embodiment of my invention applied thereto, the said apparatus being shown fragmentary and partly in section, the section being taken as on line 1-41 in Figure 5.

Figure is a top view of the printing press with my modified mist dispelling apparatus in superl posed relation.

As shown in Figures 1 to 3 inclusive, AA represents the side-frames of a printing press E, the said side-frames being apertured to receive a hollow tubular shaft C mounted in insulating bushings B and .causing the shaft to be electrically insulated from the side frames. The shaft C has a slot D extending throughout its length. A wire mesh cylinder F having spider mountings G is rotatably mounted on the shaft C in electrical contact with said shaft. 1

A wiper H, made of soft material such as felt is secured to the shaft C in line with the slot D and intermediate the spider mountings G and serves to wipe the ink particles collected on the wire mesh cylinder F into the hollow interior of the shaft 0.

Any well-known means may be employed to produce an electrical charge which may be de livered to the wire mesh cylinder 1 and shaft C by transmission through a conductor if having a positive or negative charge as desired.

The embodiment heretofore disclosed in Figures 1 to 3 inclusive consists of one elementary mist dispelling unit cooperating with two or more printing rollers or cylinders 39 and M3 for treating charged particles directly at the source where the shattering takes place. It is to be understood that several of these units may be installed on a printing press.

Another embodiment which may be employed comprises a unit which can take care of all the printing rollers in the entire press and not directly at the source of shattering, but at a point on the press removed from the operating mechanism.

In the modified embodiment of the invention shown in Figures 4 and 5, the numeral iii indicates a newspaper printing press comprising two printing couples M, ii, arranged in substantially horizontal position and respectively including the usual ink fountain 52, pick up roll it, distributing rolls l l, ink cylinder l5, an inked plate or type cylinder 06, and an impression cylinder ill.

As shown in Figure the web 118 is led upwardly into one of the printing couples l l where the printing is done on one side and is then led into the second printing couple where the printing is done on the other side of the web and then leaves the press in an upward direction. The shattering close a portion of a type cylinder and a portion of an impressioncylinderwhich jointly form a print-: ing couple. I'he housings l9 enclose the upright clearance spaces 33 between the side frames 28 and the ends of the cylinders". The upright spaces or passages 33 permit particles of ink shattered between any two contacting cylinders such as the type cylinder 16 and the form roll 34 to rise into the housing l9.

At the line where the type cylinder l6 contacts the form roll 35, I have provided a shield 36 extending the entire distance between the side frames 2|. The shield 36 prevents any shattered particles from passing sideways beyond the overhanging side walls of the housing l9.

In operating position, the housings l3 are like inverted troughs and are secured in end walls 26, which are fastened to the side frames 2| of the printing press ID by means of bolts 22. The end walls 20 have concave circular flanges 23 at their upper elevations to receive the housings l9, which are secured in position by bolts 24.

Mounted centrally in each of the housings I9 is a tube 25, the outer circumference of which is spaced away from the housing to form arcuate passages 26 therebetween. The passages 26 lead upwardly into a tubular extension 21 of the housing IS. The tubular extension 21 has a small end 28 and a large end 29. A rapidly revolving centrifugal fan 30 has been secured to the extension 21 at its large end 29 and causes an air suction upward into the housing.

A series of small diameter wire electrodes 3 have been alternately disposed in spaced relation relative to a series of large diameter electrodes 32 in the arcuate passages 26. The electrodes are positioned parallel to the type cylinder l6 and impression cylinder l1, and are of a length to be co-extensive with the cylinders. The electrodes are positioned below the tubular extension 21 and so positioned that the shattered electrically charged particles from the rollers being sucked into the housing will contact the electrodes and be attracted to electrode surfaces charged with an opposite potential.

The superposed housings IS are positioned so as to treat charged' particles from all the conparticular mode of generation of electricity and that any kind of charge may be used, such as that produced by an alternating current, a direct current or by static electricity.

I claim:

1. In an ink precipitator for a printing press having contacting inked type and impression cylinders for printing upon a web at high velocity and causing electrically charged particles of ink to leave the region of contact of said cylinders, an enclosure for a portion of the type and impression cylinders, and electrodes in said enclosure for electrically precipitating said charged ink particles.

2. In an ink precipitator for a printing press having contacting inked type and impression cylinders for printing upon a web at high velocity and causing electrically charged particles of ink to leave the region of contact of said cylinders, means for enclosing a portion of the type and impression cylinders, said enclosure comprising air suction means and electrodes for electrically precipitating said charged ink particles, said electrodes being positioned parallel to said cylinders and intermediate said suction means and said cylinders.

3. In an ink precipitator for a printing press having contacting inked type and impression cylinders for printing upon a web at high velocity and causing electrically charged particles of ink to leave the region of contact of said cylinders, means for enclosing a portion of the type and impression cylinders, said enclosure comprising air suction means and electrodes for electrically precipitating said charged ink particles, said electrodes being positioned parallel to said cylinders and intermediate said suction means and said cylinders and of a length to be co-extensive with said cylinders.

4. In an ink precipitator for a printing press having contacting inked type and impression cylinders for printing upon a web at high velocity and causing electrically charged particles of ink to leave the region of contact of said cylinders, means for enclosing a portion of the type and impression cylinders, said enclosure comprising air suction means and a series of small diameter electrodes alternately disposed in spaced relation relative to a series of large diameter electrodes, said electrodes being positioned parallel to said cylinders and intermediate said suction means and said cylinders and of a length to be co-extensive with said cylinders.

5. In an ink precipitator for a printing press having rotatably contacting inked type and impression cylinders, means comprising a housing containing electrodes adapted for electrically precipitating charged ink particles, said electrodes being operatively positioned relative to the type and impression cylinders so as to intercept said particles.

6. In an ink precipitator for a printing press having rotatably contacting inked type and impression cylinders, electrode means adapted for electrically precipitating charged ink particles, said electrode means being housed and operatively positioned relative to the type and impression cylinders so as to intercept said particles.

WILLIAM T. DIEFENBACH.

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