SE433829B - PROCEDURE AND PRESSURE EXTENSION DEVICE FOR PRESSURE PRESSURE - Google Patents

Description

7802884-2 2 The large number of paint rollers requires complicated drive sequences and is relatively expensive to purchase initially and then maintain.

To eliminate both the cost and the disadvantages of a number of paint rollers have some attempts at. has recently been developed to develop dyes in which a fresh film of paint is deposited on a mold roll which is pressurized with a printing plate to eliminate the sequence of rollers, to eliminate ghost images and to eliminate color animation and deficiency.

U.S. Patent No. 5,283,712 discloses a staining apparatus for overcoming ghost images. The device comprises two. rollers of substantially equal diameter and actuated against each other in a pressure indentation relationship to form a nip, the surfaces of the rollers adjacent the nip moving in opposite directions. One of the rollers is cleaned by a pair of doctor blades and the rollers are arranged to be actuated against each other so that the local pressure at any point selected along the contact generator or nip is greater than a "critical pressure threshold", so that theoretically one of the rollers carries a paint film of constant thickness over the entire length of the roller to be applied directly to. a pressure plate without having been brought into contact with leveling rollers.

However, the functional theory presented in the above-mentioned patent does not take into account the fact that viscosity, surface tension, cohesion of dye molecules and adhesion of dye molecules to molecules on the surface of the rollers are all related to the temperature of the dye. Thus, since adjacent surfaces of the rollers at the nip move in opposite directions and since the pressure is not uniform along the length of the nip, the temperature generated by adjacent surfaces moving in opposite directions will result in significant variations in the temperature along the length of the rollers and in the the rollers carried the paint.

In addition to the irregular temperature distribution along the length of the rollers, dyeing devices constructed in accordance with the instructions of the aforementioned patent require considerable force to bring the rollers. rotating and adjusting the thickness of one color film measured by the nip was very sensitive because small changes in the surface speed of the roll, which had been completely cleaned of color, resulted in drastic changes in the color film carried by the other roll.

It was also observed that the surface of the resilient roller tended to vibrate or vibrate as it moved through the nip and encountered considerable forces as a result of being in a pressure indented relationship with the surface of the other roller moving in the opposite direction, which resulted in pressure strips which extended across the direction of movement of the sheet through the printing press. Experience has shown that conventional viscous printing ink cannot be used in this dyeing device. It appears that the dyeing device described in the above-mentioned patent has failed to achieve commercial success due to its inability to measure a film of uniform thickness suitable for dyeing printing plate and due to the considerable requirements for power for to drive the rollers when adjacent surfaces move in opposite directions and are strongly torn against each other.

A stationary metering unit that does not require any drive other than that required to rotate a single mold roll seems to be an ideal solution to the problems encountered by prior staining devices. Attempts have been made to use doctor blades as color measuring devices, but these attempts have always failed. Scraper blades are successfully used as paint drying or ironing units in dyeing devices with a series of rollers to distribute and even out the paint, but such blades have not been found suitable for use as the sole paint measuring unit for a resilient surface mold.

Printing ink is usually an oily, viscous substance, which is highly pigmented and composed to be tacky so that the paint will adhere correctly to the image areas on the printing plate. When the image area of the printing plate transfers color directly to paper or to a felt cylinder, which in turn transfers color to paper, small paper fibers, lint, and fragments of coating material may adhere to the surface of the plate cylinder. the surface causes the foreign substance to be applied to the surface of the paint application roller. If the surface of the paint applicator roller is inserted directly into the reservoir and then ironed or scraped through a conventional soybean blade, the foreign substance tends to accumulate at the edge of the doctor blade, resulting in the formation of an irregular color film on the surface of the roll. For this reason, apart from the irregular cessation of the surface of the resilient roll under dynamic conditions, to date no dyeing device has been developed capable of supporting or carrying a doctor blade to impart a uniform color film directly to the surface of a resilient roll. in rolling engagement with a pressure plate.

U.S. Pat. No. 3,298,505 discloses a dyeing mechanism having a stationary, fully supported edge or edge obtained in a position to substantially depress the surface of a resilient roll so that a film-forming portion of the dyeing mechanism would form a thin uniform color film delivered by a slit in the staining mechanism and was applied to the roll surface. The edge is described as being expressly locked in position to prevent any lifting of the paint film on the roller so as not to adversely affect the hydrodynamic effect. 7802884-2 4 It has been observed that uniform pressure cannot be achieved between the firmly located edge and the surface of a resilient roller under dynamic conditions because it is apparent. the modulus of elasticity of the resilient roller. surface increases when the cyclic. the rate of load increases. The dimensions of the resilient mold roll also vary under dynamic conditions, if the resilient surface is subjected to cyclic loading, since resilient materials have a "memory" and do not immediately recover to an original dimension after being compressed. In addition, vibration is induced in the resilient roller surface by considerable depression of the surface as the resilient casing is unpacked as a result of the compressive load on. one side of the stationary, rigid edge and is under tensile stress on the other side of the edge. Vibrations of the roller shaft relative to a stationary, fixed edge, which vibrations result from the movement of the roller surface into and out of the gap in the plate cylinder, are not insulated. easy way from a firmly supported edge.

It should be further noted that a mechanism, such as that described in U.S. Patent No. 5,298,505, which coats the paint with a firmly supported edge, does not effectively form a thin uniform film. Furthermore, a guide mechanism does not yield simple or easy to adapt to surface variations on the roll and therefore provides a non-uniform color film in areas of desired thicknesses.

U.S. Patent No. 4,007,682 discloses a method of painting a mold roll with a resilient surface, wherein an ultra-thin doctor blade. is mounted at an opposite angle to the paint to divide the paint and apply it to the roller in the desired thickness when relative movement is provided between the roller and the doctor blade. The doctor blade is described as being flexible, for example a blade constructed of Swedish steel with a thickness of 0.20 mm in one example and a thickness of. 0.58 mm in another example.

U.S. Patent No. 4,007,682 discloses that when a high viscosity paint is used and the relative speed of movement between the roll surface and the edge of the blade is high, a sharp blade will "float" on. the color surface, but the leading edge of the doctor blade 'should be cylindrical with a radius of curvature equal to half the thickness of the blade when less viscous. colors are used. The patent states that the speed of the roll surface relative to the doctor blade is adjusted to cooperate with the color viscosity, the blade geometry and the downward force on. the blade to cause the paint to be carried into the nip between the blades. and the roll surface, whereby its viscous resistance to cutting forces creates an upward pressure which causes the doctor blade to "float" over the color film it produces. The surface speed of the roller is varied to vary the thickness of the color film formed on. waltz. The patent states that rotation of the dyeing roller at 172.72 cm / second produces a uniform coating of paint 5 microns thick and that when the rotational speed of the dyeing roller is increased to 456.88 cm / second, a dye layer is formed which is 12 microns thick. It has been observed that a wedge-shaped abutment surface on an ultra-thin, flexible doctor blade which is lightly pressed toward a roll surface as described in U.S. Pat. No. 4,007,682 causes the flexible blade to "flatten" so that the color film thickness changes with the pressing speed, resulting in color density variation on printed sheets. It has further been noted that a considerable radius on the edge of the blade forms an area in which small paper fibers and lint, commonly referred to as "hickeys", accumulate, which results in the formation of an irregular color film on the surface of the roll.

Furthermore, it appears that the cylindrical end of the doctor blade described in U.S. Pat. No. 4,007,682 is not shaped to deflect the roller surface in the direction away from the lower surface of the doctor blade and therefore paint carried by the roller surface will follow the lower surface of the doctor blade and create color. accumulation at the surface of the soybean blade, which will result in dripping; and destruction of the uniformity of the color film formed by blades.

The invention described herein relates to the problem of forming a printing ink film of uniform thickness on a resilient roll surface and bringing the color film into engagement with the image area on a silicon wafer while eliminating roll sequences in the dyeing devices, eliminating the need to consume considerable power to measure a thin uniform color film, elimination of problems associated with accumulation of "hiokeys", thereby providing a foreclosure means which does not adversely load a resilient roll surface to impart. the resilient roller surface rotates and is provided with mating means which form a uniform film, the thickness of which is independent of the pressing speed.

The improved dyeing device which is the subject of this application comprises a roller with a resilient surface arranged to be actuated to a pressure-indented relationship with a pressure plate 'in combination with an improved liquid measuring device arranged to form a thin uniform color film on the surface of the the resilient roller, the thickness of the color film being independent of the surface velocity of the resilient roller.

The roll surface moving from engagement with the printing plate is passed through a paint reservoir so that an excess of paint is applied to it. the surface of the roller. A measuring means is arranged relative to the resilient surface of the roll to form an orifice through which a thin uniform color film is extruded, which color film adheres to the resilient surface of the roll.

The measuring means is resiliently mounted so that a polished, flexible edge thereof moves relative to the axis of the resilient, covered roll and is actuated towards the resilient surface of the roll to maintain a substantially constant pressure relationship relative to the entire surface of the roll and around it. - circuit. The polished, flexible edge of the baffle is firmly supported in a direction substantially tangential to the roll surface and is shaped and oriented to deform the resilient roll surface to minimize wetting of a substantial surface area of the baffle downstream of the polished edge to effect separation of the paint from the foreclosure means adjacent to the polished edge. The lower surface of the foreclosure means is shaped and / or located so that color on the depressed, resilient roller surface does not separate from the roller surface taxi and adheres to the lower surface of the foreclosure means when the paint recovers from a compressed condition taken as a result of the passage of the foreclosure means. nets flexible., polished edge.

The flow of paint in the reservoir towards the foreclosure means is turbulent due to the structure of the foreclosure means adjacent to the reservoir and thus causes lint and other foreign material to be generally removed from a high pressure area immediately adjacent the front edge of the foreclosure means. This fluff and foreign material are retained in the reservoir and therefore the accumulation of particles against the edge of the measuring means is also minimized. The color flow carried by the movement of the resilient, surface of the roller in the direction of the polished edge of the measuring device experiences a rapid increase in pressure and the flow becomes laminar immediately adjacent to the polished edge. The paint speed increases as the paint moves through an opening or orifice between the resilient surface of the roller and the polished edge of the binder. Immediately downstream of the orifice, the paint is separated from the polished surface and the paint is retained on the resilient surface of the roll.

The polished edge of the measuring means is actuated against the resilient surface of the application roller by means of a static force within a range between about 0.177 and 1.065 kg per linear cm of the length of the edge, the force being sufficient to depress the roller surface along the entire length of the roller surface. citation modulus, casing thickness, color viscosity and others. color characteristics.

The polished edge of the measuring means easily impresses the surface of the resilient roller, for example about 0.76 mm on a 40 Shore A durometer roller with a coating thickness of approximately 7.94 mm. As the roll rotates, the polished edge of the baffle member moves relative to the geometric axis of the roll to maintain an equilibrium state so that the edge forms an opening or mouth that automatically moves radially relative to the geometric axis of the roll to form a film of uniform thickness longitudinally relative to the roll surface. periphery although the roll surface is not perfectly round and not free of slight waviness.

A main object of the invention is to provide a coloring device for printing presses which provides continuous precision control of the thickness of a color film which is delivered to a printing plate. to eliminate ghost images and resulting color variations in printed images. Another object of the invention is to provide an improved liquid metering means and an associated support device for positioning the metering means relative to a resilient roll surface to form a liquid film on the roll surface, the thickness of the film being substantially independent of the roll surface. - tighet.

Another object of the invention is to provide an improved printing ink measuring means which is particularly suitable for being actuated to such a condition relative to a roll that foreign material in the paint moving in the direction of the measuring means surface and carried by the surface of the roll is diverted in the direction from the foreclosure body.

A further object of the invention is to provide a simple and efficient dyeing device which is capable of forming a thin continuous color film of uniform thickness in the longitudinal direction and on the circumference of a movable, resilient rolling surface, the device being stationary to operate without producing too much heat and without requiring considerable force to drive the device.

Another object of the invention is to provide an improved method and apparatus for forming a uniform color film on the surface of a resilient roller, the color being measured through an opening or orifice formed between a flexible, polished edge which is resiliently pressed into direction towards the resilient roller surface so that the orifice or opening automatically moves radially relative to the roller so that the thickness of the paint film is independent of the surface speed of the roller and does not vary significantly when the speed of the printing presses changes.

A further object of the invention is to provide an improved method and apparatus for forming a uniform color film on the surface of a resilient roller by using an edge mounted on a bracket or a cantilever beam, the edge being moved in a pressure ratio with a color film on the roll surface past a threshold point where the color film ceases to decrease in thickness when an increase in force is applied to the edge and begins to increase in thickness as the color film becomes more uniform.

Another object of the invention is to provide a coloring device in which a non-rotating foreclosing means is located and arranged so that paint passing under the means while the paint is being dispensed does not separate from itself and accumulates on the lower surface of the measuring means to finally return again drawn to the measured film and destroy the uniformity.

Another object of the invention is to provide an improved dyeing device in which a polished edge of a mating member is resiliently actuated to a pressure indented relationship with a resilient roller surface so that vibrations in the printing press are isolated from the polished edge to eliminate streaks in the the dyeing device formed the color film. Another object is to provide a staining device in which a polished edge of a mating surface is affected to a pressure indented relationship with a resilient roll surface so that the angle of the mating surface relative to a radius of the roll is adjustable to adjust the thickness of a: film carried by the roll surface past the polished edge.

The invention will be further described by way of example by reference; to the accompanying drawings, in which Fig. 1 is a cross-sectional view taken across a printing press, Fig. 2 is an enlarged, fragmentary cross-sectional view illustrating the relationship between the measuring means and a resilient, coated roller, Fig. 5 is an enlarged schematic view of a first embodiment of measuring the means and a portion of the resilient surface of the application roller under dynamic conditions, Fig. 4 is an enlarged schematic view of a second embodiment of the measuring means, Fig. 5 is a sohematic view showing that when the force acting on the measuring means to pressure indented relationship with a rolling surface increases a minimum thickness of the color film is achieved, Fig. 6 is a schematic view similar to Fig. 5 and illustrating a number of curves, Fig. 7 is a schematic view showing variation of the color density laterally over a printed sheet corresponding to changes in the force affecting a edge of the xx measuring means for pressure ratio with a resilient surface, Fig. 8 is a schematic view showing position variations of an edge of. the measuring means when a resilient, coated roller rotates at a constant speed and also at varying speeds, Fig. 9 is a schematic view showing that the color film thickness is independent of the pressing speed, and Fig. 10 is a schematic view showing the color density of a printed sheet.

Reference numerals are used to denote equal parts throughout the various figures. the drawings.

In Figs. 1 and 2, the number 1 generally indicates a dyeing device with separated side frames 2, which are movably locked at side frames 5 of a printing press with a conventional plate cylinder P, a felt cylinder B and a printing cylinder I mounted in the press for printing on a weave t 'or a sheet of paper.

A support member 5 is provided to adjustably lock a foreclosure means 10 between the side frames 2 and to position the foreclosure means 10 relative to a resilient, coated applicator roller 40. Opposite ends of the applicator roller 40 are rotatably attached to the side frames 2 in suitable bearings and the applicator roller 40 is driven by any suitable drive device, such as a chain 4, as on. drive way connects a sprocket. the plate cylinder P with a sprocket on a clutch (not shown) at one end of the applicator roller 40. The surface velocity of the applicator roller 40 is preferably equal to the surface velocity of the plate cylinder P.

However, the surface velocity of the applicator roller 40 may be about 10% faster or slower than the surface velocity of the plate cylinder P to facilitate cleaning of non-reproducing areas on the plate cylinder P. End dams 6 are attached to the s-support member 5 and actuated to sealing joints with opposite ends of the applicator roller 40 and the measuring means 10 to form a reservoir E, from which ink is measured. the surface of the applicator roller 40. One or more vibrator rollers 8 are located in rolling engagement with paint on the surface of the applicator roller 40 to smooth out any surface irregularities that may occur in the paint film before: the paint film is carried by the surface of the roller 40 to the surface of a printing plate P1 on the plate cylinder P. The vibrator rollers B are in printing with ink on the surface of the applicator roll 40 and serve not only to smooth surface irregularities, but also to change a smooth measured finish to a smooth matte finish to condition the color film for proper printing on a representation on a printing cylinder. .

It should be noted that as soon as the surface of the applicator roller 40 moves away from the surface of the printing plate P1, the surface ink is soaked in ink and an excess of ink is applied to it at the reservoir R.

If the dyeing device is used for lithographic printing, moistening fluid is applied to it. the surface of the pressure plate P1 on the plate cylinder P, is arranged to force such a humidifying fluid from the surface of the vase 40 to prevent the accumulation of too much humidifying fluid in the reservoir R. As shown in Fig. 1, a hollow, perforated tube extends 9 across the side frames 2 and has openings through which. dried, compressed air is discharged to cause a stream of dry air to be directed towards the surface of the roller 40. One end of the tube 9 is connected by a line to an air compressor (not shown). When the humidification fluid is used with the staining device according to the invention, a larger proportion of alcohol relative to water than normal can be used to accelerate the evaporation of the sparking fluid remaining on the applicator roller 40 as it moves away from the pressure plate P1. The humidification solution may contain more than the normal 5 - 25% alcohol to ensure rapid evaporation of the humidification solution from the applicator roller 40 during the movement between the plate P1 and the paint measuring means.

As will be explained in more detail below, in order to provide precision control of the dye viscosity in the reservoir R and to vary the dye viscosity in the dye reservoir, flexible tubes are connected to deliver fluid, such as water, at a controlled temperature and at a controlled flow rate. at one end of a passage 5 'in the support member 5 and out of the other end of the passage 5'.

For high speed throttling of webs, the physical properties of the color film 150 formed between the baffle 10 and the resilient casing 40 of the roll 40 can be controlled by temperature control of a fluid passing through the vibrator rollers 8 and through a passage in the core 40 of the roll 40. It has been found that a high flow rate gives only a slight temperature change along the length of a roll and that by monitoring and controlling the outlet temperature heat can be dissipated 1ßo2sa4-2 w and the color temperature is regulated so that the physical properties of the formed film are kept substantially constant throughout the length of a production run.

Therefore, by cooling and / or heating fluid passing through the support member 5 and the roll core 42, the color viscosity at the shear nip can be controlled to maintain a constant desired. color film for correct printing on the plate P1.

Two alternative embodiments of the color measuring means 10 are illustrated in Figs. 5 and 4, respectively, in the drawings.

In Fig. 5, the color measuring means 10 has a smooth, polished, highly developed, precision edge or edge 15, which is formed at the junction of the surfaces 12 and 18.

The edge 15 advantageously extends in terms of length over a distance within a range from 25.4 to 254 cm and is limited by polished portions 14 and 16 on the surfaces 12 and 18. The polished portions 14 and 16 meet each other to form a wedge with an edge phase angle a on. approximately 9130. Although an angle of 900 between the portions 14 and 16 has been found to be very effective in forming the precision edge 15, the edge 15 may also be formed with the polished portions 14 and 16 at other angles of less than 1200 'and larger. than the GOO edge 15 is formed of relatively hard material, normally metal is used. The material advantageously has a hardness: within an area between Rockwell C10 and Rockwell C60 and preferably about Rockwell C50.

The measuring means 1.0 is advantageously a resilient metallic material with a modulus of elasticity in a range between 1.05 and 2.1 x 106 kg / cm 2 and preferably about 2.03 x 106 kg / cm 2.

The measuring means 10 has with good results been formed of a strip of stainless steel of the type used in the manufacture of compressor valves, which steel is commercially available from Uddeholm and is distributed as UHB Stainless 716.

The stainless steel strip had a thickness of 0.79 mm and a width of. 88.9 mm. The material strip had a clear, extra finely polished surface finish, bevelled edges, extra careful flatness and normal straightness. Because the strip of stainless steel material was hardened and tempered, it was. resistant to corrosion in the presence of air, water and most organic acids in dilute form at room temperature.

The stainless steel strip was chosen for its hardness; flatness, »resilience and fine surface finish to provide high durability and good fatigue properties.

Before polishing, the edge 15 when joining the surfaces 15 and 18 formed a line consisting of uneven notches which formed an uneven edge contour. To form a straight precision edge to provide a solid line across the extent of the measuring means 10, several segments of the strip material were clamped together and their surfaces 12V were ground simultaneously and honed with a fine-grained stone as a first step in the formation of the peiemae edge 15. 11 7802884-2 A pair of strips or strips, of which the measuring means 10 were to be formed, were then clamped in a vice with a spacer between the strips, the surfaces 12 of each of the strips being located in a common plane. to support a grinding block. The surfaces 12 of each of the strips were then smoothed with sandpaper having grain sizes of 520, 400 and 600 and then polished with high gloss polishing cloth.

As a third step, the pair of stainless steel strips were placed on a flat horizontal surface so that each surface 12 was adjacent to the other. the surface 12, the surface 19 of each strip or strip being supported on a liner; so. that the edge 12 was inclined at an angle of about 0.2 ° from a vertical line. The polished part 16 on. each surface 18 was then smoothed with sandpaper with grain sizes 520, 400 and 600 and then polished with high gloss polishing fabric or fabric.

If a sharp edge is formed on the measuring means 10 while the portions 14 and 16 of the surfaces 12 and 18 are ground and polished, the sharp edge must be removed. When the sharp edge or wire-like irregular edge is removed, a microscopic curve is formed on the edge 15. In the method of polishing or "sharpening" the edge 15, the sharpness of the edge 15 should be changed slightly to form a non-cutting edge which does not penetrate the film. This method gives a fine, continuous, smooth, smooth, polished, highly developed edge or edge 15 with minimal surface irregularities. There must be no small notches or protrusions in the edge 15. The developed edge 15 formed by the polished portions 14 and 16 on the surfaces 12 and 18 'air a very fine edge which has been polished to give it a highly developed finish and as close to perfect condition as possible.

The edge 15 is surface treated to a surface finish which is approximately equal to that of the edge of a razor blade. However, it can be noted that the angle α between the polished portions 14 and 16 on the surfaces 12 and 18 is considerably larger than a phase angle α 'which, for example, is provided. a razor blade and thus a blunt, non-cutting and non-penetrating edge is formed. In fact, the portion 14 in the portion 16 merges with the edge 15 to form a continuous, polished surface near the edge 15.

The material used to form the edge 15 must not only be hard and capable of being formed. to give a blunt, fine, polished, unbroken edge, the Ixtan material must also be flexible along the length of the edge. In themselves. the workpiece 15 must be rather flexible in the longitudinal direction so that when pressed to the pressed surface with the resilient surface of the applicator roll 40, the edge 15 will bend while yielding to the surface of the roll 40 to conform to the edge 15 and the roll 40. surface. to form a uniformly depressed area along the length of the roll 40. As will be explained in more detail below, the surface of the roll 40 has a thickness of approximately 6.55 mm and a resilience of about 40 Shore A durometers. This bending of the edge 15 to achieve adaptation to the surface of the roll 40 should be possible without excessively depressing the surface of the roll 40 when it is in a static state. The edge 15 of the measuring means 10 should be arranged so that it is resiliently pressed in the direction of the surface of the applicator roll 40 and is free of movement in a direction radially relative to the applicator roll 40. The edge 15 must also be constantly supported in a direction substantially tangential relative to the surface of the applicator roller 40.

An ideal support for the edge 15 is a flexible cantilever beam, which supports the edge 15 and provides the required prestressing and rigidity. Although the edge 15 may be part of a separate element attached to a cantilever beam, it is preferred to form the edge 15 on it. the beam so. that the two form a unit in one piece.

To achieve this, the beam must be built of a material of the type necessary for the edge 15 and it must be flexible in two directions, namely along the length of the edge and also along the width of the belt or the length of the cantilever beam.

The ink measuring means 10 shown in Fig. 3, in which the edge 15 is formed on the unsupported end of a cantilever beam, has a substantially rectangular cross-section limited by the surfaces 11, 12, 18 and 19. The surface 12 lies in a plane 12 ', which intersects a plane 18', in which the surface 18 lies when the cantilever beam is in a non-raised condition. The planes 12 'and 18' intersect at a tip A which is a straight line.

As an example, the cantilever beam comprising the edge 15 may be. formed of a thin, flexible, elongated, stainless steel strip, as described above, with a thickness of 0.79 mm and a width of B_8.9 mm. The width of the beam or the length of the material strip preferably in the range from 25.4 to 254 cm and the beam is supported as such. that it is flexible along the length of the edge 15 as well as along the length of the cantilever beam. The modulus of elasticity E of the beam can be, for example, 2.05 x 106 kg / cm 2, which represents the stiffness of the material; i.e. its resistance to deformation. When combined with the moment of inertia I, the EI factor represents the rigidity of the cantilever beam.

The specific dimensions and characteristics of the measuring means 10 are presented for exemplary purposes and such dimensions, characteristics and mounting methods may vary to meet specific conditions. Consequently, preferred areas have been discussed here.

A second embodiment generally denoted by the number 10 'is shown in Fig. 4 of the drawings.

The ink measuring orgasm shown here '10' will finally have a fine, polished, highly developed, preoision edge or edge 25, which is. formed at the junction of the polished surfaces 24 and 26 using the method described above to form the edge 15 of the member 10. The measuring means 10 'differs from the measuring means 10 mainly in that a groove or cut-out area 27 is formed in the lower surface 28 of. the strip of material from which the measuring means 10 'is formed.

The strip of material from which the measuring means 10 'is formed is preferably of stainless steel or a high carbon steel having a thickness of. about 1.27 mm and a width of about 88.9 mm.

The portion of the strip of material or strip to be polished to form the polished edge 25 is masked and the metallic material adjacent to this edge is removed by chemical milling to remove a portion of the metal without relieving or generating stress which would be able to make the material band skewed.

The surfaces 289. which delimit the support area are leveled by grinding to remove approximately 0.076 mm of uneven surface material. The surfaces delimiting the removed area 27 can then be electropolished to give a very smooth surface finish. These surfaces can be electropolished by making the member 10 'the anode of the electropolishing process and immersing it in an electrolyte containing phosphoric acid. and butyl alcohol so that the high points of. the surfaces will dissolve in the electrolyte.

If the thickness, i.e. the distance between the lower surface 28 and the upper surface 29, of the material strip is 1.27 mm, the depth of the unloaded area 27 is preferably about 0.51 mm so that the thickness of the material between the surface 28 'and the surface 29 is approx. - approximate 0, 7 6 mm.

The surface 28a intersects the polished surface 26 at an angle A 'in a range between 50 and 90 ° as shown.

The upper part of the surface 24 of the measuring means 10 'is chamfered at an angle of approximately 50 ° to form a surface 22.

In the illustrated embodiment of the measuring means 10 ', the polished surface 24 extends upwards from the polished edge 25 a distance which is approximately equal to the depth of the relieved area 27 or approximately 0.508 mm to cut the surface 22. It should be clear. that the polished surface 26 supports or carries the polished edge 25. If the surfaces 24 and 28a are parallel, the surface 26 can again be surface-treated without changing the load-bearing characteristics of the polished edge 25 of the measuring means 10 '.

However, it should be readily understood that the surface 22 may be shaped so as to extend through the polished edge 25, if it is deemed appropriate to do so. that the polished surface 24 and the surface 22 lie in a common plane.

The relief or clearance angle A "" should be sufficient to cause a color film worn on the surface of the roll 40 to deviate and separate from the surface 26 without accumulating either. surface 26 or surface 28a to effect final drip of the accumulated paint to effect non-uniformity. The applicator roll 40 comprises the core 42, which has a hollow, rigid tubular shape and has the resilient casing or cover 44, which is non-absorbent, attached to the core, the casing 44 having a uniformly smooth and resilient outer surface 45. Although resilient the housing 44 on the applicator roller 40 is relatively stable, for example in a range between 50 and 90 Shore A durometers.

The housing 44 of the applicator roll 40 is advantageously formed of a resiliently resilient urethane, polyurethane or a rubber-like material attached to the metallic core 42.

The housing 44 of the applicator roll 40 should have high tensile strength, excellent compressive and abrasion resistance and resistance to oils, solvents and chemicals.

The casing should also have a low compression set, good resilience and uniform color receptivity. A suitable casing or coating may be formed using a resin commercially available under the registered trademark "Solithane" from Thiokol Chemical Corporation, of Trenton, New Jersey, in combination with suitable plasticizers to form a resilient casing of about 40 Shore A durometer.

After the resilient casing 44 has been formed, the roller 40 may have a glossy, smoothed outer skin or film over its surface and this may be removed by grinding.

After this grinding, the plastic surface is ground using a sandpaper with a grain size of 180 to form a surface of uniform roughness over the outer surface 45 of the resilient casing 44. Microscopic reservoirs in which ink is retained ensure that a continuous color film is maintained. on the outer surface 45 of the applicator roll 40. Final surface treatment using different sandpaper to grain size 400 is performed to ensure a velvety smooth surface free of "an orange peel" or other surface irregularities. As will be explained in more detail below, the adhesive force between dye molecules and molecules of the outer surface 45 of the casing 44 must exceed the cohesive force between the dye molecules to allow cutting of the dye to form a controlled dye film on the surface 45 of the applicator roller 40.

It is understood that it is physically impractical, if not impossible, to make the roller 40 so that the surface 45 is perfectly round in the circumferential direction, perfectly straight in the longitudinal direction and walking concentric with the axis 42 of the core 42. The straightness of the surface 45 of the roll 40 / is economically kept within a tolerance of about 0.051 mm along the length of the roll 40 and the radial eccentricity can be economically kept within a tolerance of about 0.058 mm.

A Shore A durometer sample is commonly used to indicate the hardness of a resilient roll casing by measuring the penetration resistance at a constant temperature of about 24,500 while the resilient casing is stationary. The apparent hardness of a resilient surface under dynamic conditions differs radically from the hardness indicated by the durometer sample under static conditions. The spring constant of a resilient material also increases slightly as the deformation increases.

As the loading frequency of a resilient member increases, the dynamic modulus of elasticity or apparent modulus of elasticity increases, causing the casing to appear as a harder, stiffer material. However, occlusal loading of a resilient member results in the generation of internal heat, with the increase in temperature resulting in a decrease in the durometer and therefore in the modulus of elasticity of the resilient casing.

Furthermore, since the surface 45 of the casing 44 on the roller 40 is advantageously pressed against the surface of the plate cylinder P, which has a gap extending in its longitudinal direction, this cyclic load will result in the generation of heat at an irregular speed on the circumference of the surface 45. . Such temperature differences across the surface 45 can cause a significant variation in the radial distance from the axis of the roll 40 to points above the surface 45 because the coefficient of thermal expansion of elastomeric materials used to form resilient roll heights is several times the coefficient of thermal expansion of steel.

As shown, the roll 40 may be different in diameter from the plate cylinder P without adversely affecting the sizing of the color film 150 because the sizing means 10 or 10 'provides a continuous ink strip independent of the previous indentation and independent of thermal changes within the roll casing 44.

As shown in Fig. 1 of the drawings, the support means 5 for supporting the measuring means 10 in a cantilevered manner comprises an elongate, rigid support rod 50 with a ground and really flat surface 52 on one side and a surface 54 arranged at an angle relative to the flat surface 52 below forming a shoulder 55 extending longitudinally relative to the support rod 50. Bearing 56 extends outwardly from opposite ends of the support rod 50 and is rotatably attached to a self-aligning bushing 57 in bearing blocks 60 with outwardly extending projections 58 next to opposite sides thereof.

Each of the protrusions 58 has an elongate slot through which anchoring bolts 52 extend to secure the bearing blocks 60 to the vein frame 2 of the staining device.

Four height adjusting screws 64 extend through threaded passages in the projections 58 on the bearing blocks 60 and engage a surface 65 of the color frame side frame 2 for movement of the support rod 50 in the vertical direction, as illustrated in Fig. 1.

Side adjusting screws 66 extend through threaded openings in outwardly extending flanges 68 on the side frame 2 of the staining device and engage an end surface 66 'of the projections 58. From the foregoing it should be fully understood that the position of the bearing block 60 is adjustable vertically and horizontally, as the device is shown in Fig. 1 of the drawing, for movement of the support rod 50 relative to the axis C of the roller 40.

An arm 70 is bolted or on. otherwise attached to the end of a bearing 56 on the support rod 50 and actuated by a piston rod 71 of a fluid pressure operated cylinder 72 to engage one end of a stop screw 74, which is threadedly locked to an arm 75, which is bolted or on. otherwise attached to the bearing block 60. It should be clear that the support rod 50 is rotatable relative to the bearing block 60 by adjusting the position of the end of the stop screw 74 relative to the arm 75.

A pressure regulator H1 is installed for the purpose of adjusting the inlet pressure in the cylinder 72 sufficiently to hold the arm 70 firmly against the screw 74 for all depressions of the edge 15 into the surface 45 of the housing 44.

The measuring means 10 is attached to the flat surface 52 of the support rod 50 by means of bolts 76, which extend through spaced openings in a clamping means 78, through oversized spaced openings extending through the cantilever beam adjacent its rear edge. The bolts 76 are the threaded attachment of threaded passages formed in the support rod 50. The bolts 76 and the clamp * 78 cooperate so that the measuring member 10 is uniformly attached or supported by the support rod 50 so that the edge 15 has a uniform resilience relationship along its length.

In the embodiment of the apparatus illustrated in Fig. 1, the stop screw 74 is remotely controlled by an electrically driven DC motor 80 which is attached to the arm 75 by a support bracket 81. If it is deemed appropriate to do so. For example, a downshift shaft arrangement may be provided between the motor 80 and the screw 74 to further control the rotational speed of the screw 74. A spline clutch 76a is coupled between the screw 74 and the output shaft of the motor 80. The engine 80 may be of the type commercially available from the Globe Industrial Division of TRW, Inc. of Dayton, Ohio. The conductor 82 and 84 extend between the motor BO and a motor position control unit 85. The motor position control unit 85 is of conventional design and comprises a direct current source and a three-position switch. The I-position position controller 85 has a digital readout indicator 86 for indicating the position of a rotary potentiometer (not shown) at the end of the stop screw 74 which engages the arm 70 to provide a visual indication of the position of the support rod 50 in front of the foreclosure means 10 or the foreclosure means 10 '. The motor position control unit 85 is attached to the side frame 5 on. the printing press in the embodiment illustrated in Fig. 1.

However, an additional motor position control unit 85 is advantageously located near the discharge end of the printing press so that the position of the measuring means 10 can be set at a distance as printed sheets are inspected for adjustment. the ink density of the ink to the required degree. The side frames 2 are pivotally attached by a shaft 90 to the press side frames 5 adjacent the opposite sides of the printing press. A fluid pressure actuated release cylinder 92 is pivotally attached to flanges 95 attached to the side frames 5 of the printing press and has a piston rod 94 which is pivotally attached to a flange 95 which is welded or otherwise attached to the paint frame side frames 2. A stop adjustment screw 96 is threaded at a flange attached to the press side frame 5 and is located to engage the side frame 2 of the dyeing device when the pressure between the outer surface 45 of the applicator roller 42 and the pressure plate P has been properly established. A stop-stop adjusting screw 98 is the thread locked to a flange which is welded or otherwise attached to the frame 5 of the printing press to engage the side belt 2 of the inking device when the piston rod 94 of the release cylinder 92 is extended to thereby separate the surface 45 of the applicator roller 40 from the printing plate. P1 surface.

As described above, the end dams 6 are actuated in sealing relationship with the opposite ends of the applicator roll 40 and form opposite ends of the reservoir R. A color retainer 100 is located in sealing relationship with the surface 45 of the applicator roll 40 as illustrated in Figs. 1 and 2 of the drawings and has opposite ends attached to the end dams 6. The lower edge 102 of the color retaining means 100 is preferably slightly spaced from the surface 12 of the color measuring means 10, for example by 0.635 mm.

The color retention oxygen 100 forms the inlet side of the reservoir R.

The outlet side of the reservoir R is formed by a member 105 which is attached to the support rod 50 by bolts 106. A lower seal 106 adjacent the member 105 is located adjacent the upper surface 19 of the measuring member 10 to prevent color flow from the reservoir R up to the upper surface 19 of the measuring member 10. so that a stagnation area is formed in which color ceases to flow. Since the ink is thixotropic, the viscosity of the ink is significantly reduced when the ink is in motion compared to the viscosity of the ink when it is not in motion.

As illustrated in Fig. 1, an ink stirrer 110 is attached to the ink retaining means 100 to stir the ink to the reservoir R.

The paint stirrer 110 is of conventional design and commercially available from Baldwin-Gegenheimer of Stamford, Connecticut, Ußå.

The ink stirrer 110 typically includes a rack and pinion that extends longitudinally across the top of the reservoir R and carries a mixer head driven by a chain driven by a constant speed motor. As the mixer head approaches the end dam 6 adjacent one end of the applicator rollers 40, it reverses its direction and it moves to the other end of the reservoir. The agitator rotates inside the ink to laterally stir or cut the ink to prevent viscosity irregularities along the reservoir. The operation and function of the apparatus described above is as follows: The ejecting member 10 is aligned and secured to the surface 52 of the support rod 50 by means of the bolts 76. Anchoring bolts 52a. unloaded to allow movement of the bearing blocks 60 relative to the side frame 2 of the paint device.

The side adjusting screws 66 'are used to move the bearing block 60 relative to the applicator roller 40 to align the edge 15 of the baffle member 10 relative to the surface 45 of the resilient housing 44 of the applicator roller 40.

The height adjustment screws 64 are used to adjust the angular relationship between the surface of the measuring means 10. 12 relative to a radius of the applicator roller 40.

After the edge 15 of the measuring means 10 has been aligned with the surface of the applicator roll 40 and the angular relationship between the surface 12 and a line extending radially relative to the applicator roll 40 has been determined, the anchoring bolts 52a are tightened, firmly locking the bearing blocks 60 relative to the side frames 2; The edge 15 is now in position in "kissing" contact with the surface 45 of the applicator roll 40. An amount of paint in excess relative to that required to color the plate P1 on the plate cylinder P is provided from the reservoir R to the surface of the applicator roll 40 approaching the mating surface 12 of the measuring means 10. After the edge 15 has been brought into "kissing" contact with the surface 45, the stop screw 74 is turned, whereby the support rod 507 pivots from the position shown in solid lines in Fig. 2 to the position illustrated by dashed lines. This results in deflection. of the cantilever beam and the flexible, polished edge 15 are actuated to a depressed ratio to conform to the resilient surface of the applicator roller 40. The rotation of the roller 40 now brings ink from the reservoir R into contact with the edge 15 and the mating surface 12 thus cuts or shears. ink of limited thickness on the surface 45 of a film 150, the thickness of which may change as will be explained in more detail below.

Assuming that the edge 15 is mounted on a cantilever beam, which is firmly supported at one end, the equation for the elastic curve is Y = F (2L5x + 1: 5) 1'- 6EI.

In the prototype, the distance between the shoulder 55 and the foreclosure means 10 of the foreclosure means -12, which is the unsupported end of the cantilever beam, was 41.275 mm, the distance between the surfaces 18 and 19 was 0.787 mm and a static load of 0.72 kg per width centimeter was applied to the edge 15. The modulus of elasticity E of the measuring means 10 was 1.89 x 106 kg / cm 2.

The moment of inertia I of a rectangular surface is equal to bhö å- 12, where b is equal to the width of the base of the rectangular surface and is equal to the height of the rectangular surface. The moment of inertia Ia of the measuring means 10 with a thickness of. 0.187 mm was calculated to be 0.945 x 10-6 per cm width of the cantilever beam. 7802884-2 19 At the unsupported end of the cantilever beam, x is equal to 0 and therefore the deflection Y is equal to FL5 4 5 EI. It was therefore calculated that the deflection of the cantilevered beam of the cantilever beam would be approximately 2.255 mm when a load of 0.177 kg / cm width is applied to the edge 15. Therefore, it was concluded that the spring constant of the cantilever beam would be 0.56 mm of deflection per 0.45 kg force applied to edge 15 or 7.965 kg per cm width of edge 15.

It should of course be understood that the equation for the above elastic curve is only approximate for calculating the deflection of the edge 15 since the measuring means 10 is not firmly supported or clamped at the shoulder 55 on the support rod 50. However, it will be clearly understood that the edge 15 resiliently actuated or pressed in a direction radially relative to the applicator roller 40.

The deflection or the distance that the edge 15 of the measuring means 10 is moved was measured in the example above to 5.08 mm when an average static force of 0.708 kg / cm was applied to the edge 15. Division of the force of 0.708 kg / cm with the deflection of the measuring means 10 gives that the spring constant of the measuring means 10 is low and approximately 5.54 kg / cm deflection. The spring constant calculated from the actual deflection of the resilient member 10 differs from the approximate spring contact calculated as above. However, the differences were predicted with respect to the spring constant as this was calculated approximately and actually measured.

As will be explained in more detail below, the total distance that the edge 15 is deflected plus the distance that the edge 15 is pressed into the roll surface should be significantly greater than the maximum distance between points on the roll surface 45 and the edge 15 when the surface 45 and the edge 15 are affected by "kissing". For example, irregularities or manufacturing defects in the roll surface 45 and slight waviness of the edge 15 can result in a maximum deviation error of 0.05 mm so that the surface 45 and the edge 15 do not mesh with each other when first touched. If the edge 15 is deflected 5.08 mm and pressed into the surface 45 a distance of 0.76 mm, the initial deviation of 0.05 mm will be about 1% of the total or combined distance of 5 mm. Since the edge 15 and the housing 44 are resilient, the edge 15 and the surface 45 will bend or yield and conform to each other.After such an adjustment, the pressure along the edge area will be substantially constant and the effect of small differences will a tt be insignificant.

The composite deflection and indentation distance is preferably greater than ten times the initial deviation so that the maximum error after the edge 15 and the surface 45 are actuated to the indented relationship will be less than ten percent to maintain a color film thickness which will print whatever those skilled in the art are considered as acceptable uniformity of color density. For what is referred to as "very solid" control, the color density should not vary more than five percent over the surface of a sheet. As illustrated in Fig., The edge 15 of the measuring means 10 is exposed to the indented relationship with the surface 45 of the applicator roller 40 so that the resilient material is stacked or solitary upstream of the surface 12 to form a swelling or wave 120 in the housing 44 while grooves or a channel 125 are formed in the casing 44 downstream of the edge 15. This forms an orifice or orifice through which printing ink is extruded, the orifice or orifice being bounded on one side by a portion of the surface 12 and the rim 15 and on the other side being bounded by a portion of the surface 45 probably between the top of the swelling 120 and the portion of the surface 45 immediately adjacent the polished edge 15. Since the cantilevered beam allows the flexible edge 15 to follow the contour of the applicator roll 40, the mouth or opening automatically moves radially relative to the applicator roll 40. axis C. Since the opening or mouth is formed by the interaction of the opposite flexibly biased edge 15 and resilient surface 45 of applicator roller 40 make this movement desirable if a constant pressure ratio is to be maintained in the ink extruded through the orifice. The surface 45 of the applicator roll 40 will continuously change its contour as the roll rotates due to elastic "memory", temperature changes and variations in the dynamic modulus of elasticity as discussed above. Consequently, it is important that the edge 15 should automatically move radially and bend longitudinally to follow its varying contour.

It should be noted that the ink * carried by the surface 45 of the applicator roll abuts the mating surface 12 and creates an area of turbulent flow adjacent the top of the swelling 120 in the resilient roll surface 45. Although the edge 15 is resiliently pressed in the downward direction as shown in Fig. 3, the measuring surface 12 is shaped and located to prevent lifting of the edge 15 by hydrodynamic forces exerted on it. the measuring means 10 through the ink. This condition is established by locating the polished edge 15 so. that it is closer to the central axis C of the applicator roller 40 than any other point = on the measuring means 10.

The blunt, polished edge 15 advantageously deforms the resilient casing 44 of the applicator roller 40 to form a compression molding to form a color film. with precisely regulated thickness.

The surface 18 of the measuring means 10 immediately downstream of the polished edge 15 is located so that the measured color film is in contact with the measuring means 10 only 7 at the edge 15 to cause the color film 150 to immediately separate from the measuring means 10 to prevent dragging of the paint along the surface. 18, which would result in color accumulation, dripping and consequently uneven flow which would destroy the uniformity of the film 150. In the embodiment of the measuring means 10 illustrated in Fig. 4, the lower surface of the measuring means 10 'has been shaped so that the surface 28a at the heel of the polished surface 26 and adjacent to the unloaded area 27 is angularly arranged relative to the direction of movement of the color film 150. that the roll surface 44 cannot return. to a position where the color film 150 is in contact with the surface 28 '.

Thus, in the embodiment of Fig. 5 as well as in the embodiment of Fig. 4, the measuring means 10, 10 'is formed or located to cause the color film to immediately separate from the measuring means 10, 10' before the roll surface 45 returns to its relaxed, non-depressed location.

During testing of the apparatus described above, it was found that when the force acting on the edge 15 to the indented relationship with the surface 45 is initially increased, the thickness of the film 150 decreases to a minimum thickness and then, with further force dissolution, the film 150 begins to increase in thickness.

Referring now to Fig. 5, it should be noted that this surprising phenomenon occurs when the force forcing the edge 15 of the discharge member 10 formed by a cantilever beam in the direction of the roller 40 (surface 45) is increased. When a light pressure per linear length unit of the edge 15 was used to press the edge 15 to pressure »in connection with the surface 45 the color density decreased when load was applied and the same was uniform around the circumference of the surface 45 of the roller 40. With this light load, however, the color density was not uniform laterally across the length of the roll 40.

As the force increased, the color film thickness lens on the roll was reduced until a slightly higher load per width unit of the edge 15 was reached. The color film thickness then began to increase as the force pressing the polished edge 15 against the central axis C of the roll 40 increased. Expressed in other words, when the force increased, the film thickness was first reduced and the same then began to increase when additional load was applied. However, the color density became extremely uniform laterally over the length of the roll 40 as the load approached a static average force of. 0.708 kg / cm on. edges 15.

This phenomenon, where at a threshold pressure the color film thickness suddenly ceases to decrease and begins to increase when the force on. the edge 15 becomes larger, has been observed when the edge 15 constitutes the lower, leading edge of a foreclosure means in the form of a cantilevered beam. Figs. 5 and 4 show the measuring means 10 and 10 ', respectively, in such a pressed-in connection with the surface 45 of the roller 40 at such a location that the edge deflection load, the pressure and the indentation and therefore the color film thickness (which determines the color) are substantially constant. With continued reference to Fig. 5, it should be noted that the thickness of the color film 150 varies as a function of the indentation of the depolarized edge 15 into the resilient surface 44 of the applicator roller 40. When, as described above, the indentation increases. , the thickness of the color film 150 decreases rapidly to a ninixnurx and this then begins to increase. Unevenness or inaccuracies in the surfaces of the output means 10 and the applicator roll 40 can be easily seen in the measured color film 150 until the polished edge 15 is pressed to a point where the variation in edge deflection, for example, is less than 10 percent) At this point, the color film 130 becomes more regular and uniform and it remains substantially uniform as the polished edge 15 is further deflected and pressed into the surface 45 of the applicator roll 40.

It has been observed that the thickness of the minimal color film, as indicated at the bottom of the curve in Fig. 5, is controlled by the angle of the measuring surface 12 relative to the radius of the roller 40.

Referring now to Fig. 5, when the mating surface 12 pivots about the polished edge 15 from the position shown, in which the mating surface 12 is inclined towards the top of the swell 120, clockwise in Fig. 5 to a position in which the mating surface 12 passes a line extending radially relative to the roller 40, the minimum film thickness of the archives in FIG.

Thus, by adjusting the angle between the measuring surface 12 and a radius of the roller 40, a family of curves such as that shown in Fig. 5 can be generated as shown in Fig. 6. From the above it should be clear that the thickness of the color film 150 can be adjusted by rotating the mating surface 12 around the polished edge 15 or by increasing the indentation of the polished edge 15 into the resilient surface 45 of the applicator roller sex 40.

It has also been observed that the thickness of the film 150 can be changed by varying the viscosity of the paint in the reservoir R. Thus, by adjusting the temperature of water or any other suitable liquid through the tubes 7 and the passage 5 'in the support rod 50, the viscosity of the paint in reservoir R is adjusted.

It should be noted that the obtainable minimum film thickness as a result of adjusting the angular relationship between the baffle surface 12 and a radius of the roller 40 can result in complete removal of color from the surface of the roller 40 before the point at which the film thickness begins to increase. Thus, to prevent damage to the surface of the roll 40, the color film thickness should be observed while making adjustments. When the film 150 becomes very thin, the applicator roll 40 should be stopped while the force which presses the polished edge 15 into the pressed relationship with the roll 40 is increased. After the force has been increased sufficiently to pass through the minimum film thickness threshold, the roller 40 can be rotated without risk of loss of the lubrication qualities of the film 150. Fig. 7: schematically illustrates the phenomenon discussed above, which results in increasing uniformity of the color density of the paint on a printed sheet as the force resiliently pushes the edge 15 to the pressed relationship with the surface 45 of the roller 40 increases.

As previously described in the azun labels regarding: Pig 10, the ink density of ink printed on a sheet was measured at points above the surface of the sheet. Readings on maximum and minimum color density were noted. Sheets were selected which were printed with different loads applied to them. edge 15 of the measuring means 10.

It can be noted that the variation in color density between the maximum and the minimum on a sheet decreased as the force acting on the polished edge 15 to the pressed ratio with the resilient casing 44 of the roll 40 increased, as indicated by the length of lines 131, D2, 135 and 34 in FIG.

It will be appreciated that as the force acting on the rim 15 to be pressed relative to the surface 45 increased, the foreclosing member 10, which is a cantilever beam, was deflected; the resilient cover 44 on the roller 40 was deflected or depressed and the edge 15 was easily deformed along its length so. that the edge 15 and the surface of the roller 40. 45 immediately thereafter were adapted to each other even though the edge 15 and the surface of the roller 40, when located in "kissing" contact, did not match perfectly. Thus, the deflection of the measuring member w, the deflection of the edge 15 along its length and the indentation of the housing 44 contribute to achieve. correct color film thickness and color density uniformity over the surface of a printed sheet.

Reference is now made to Figs. 7. It can be noted that the color film thickness decreases to a minimum and then begins to increase as the force acting on the edge 15 to the pressed relationship with the roll surface 45 increases. Thus, the same color film thickness is achieved at two different points on the curve. However, as indicated by the difference in length on lines 132 and D4 in Fig. 7, the color density variation is different at the two points on the curve.

Referring now to Fig. 8, an indicator clock was attached to the support rod 50 and placed in engagement with the upper surface 19 adjacent the foreclosure surface 12 of the foreclosure means 10. When the applicator roller 40 was caused to rotate, a total indicator clock indication was observed. 0.0152 mm. This indicated that the throw in the radius of the surface of the roller 40 was 0.0076 mm and that the edge 15 of the measuring means 10 moved; 0.0152 mm at each revolution of the roller 40. As the surface speed of the roller 40 increased, the magnitude of the movement of the edge 15 remained substantially the same at different surface speeds of the roller 40. However, the overall deflection of the baffle 10 increased slightly as the surface speed of the roller 40 increased. The polished edge 15 of the measuring means 10 thus moves automatically relative to the axis 0 of the applicator roller 40 at each revolution of the applicator roller 40 and in response to changes in the speed of the applicator roller 40. Fig. 9 shows that the color film thickness remained substantially constant over a wide speed range and that it is therefore substantially independent of the surface speed of the applicator roll 4.0.

As described above, the edge 15 of the measuring means 10 automatically moves in the radial direction when the applicator roller 40 rotates. However, the measuring means 10 is located so that the measuring surface 12 and the polished edge 15 are firmly supported in the tangential direction. It can be noted that the force imparted to the measuring surface 12, as a result of the application of paint to said surface, is directed substantially tangentially relative to the applicator roller 40 and the measuring means 10 is angularly located so that it is very rigid in one direction substantially. tangential relative to the applicator roller 40.

Although it is necessary for the measuring means 10 to be resiliently positioned to act on the edge 15 in the radial direction, the measuring means 10 must be of sufficient thickness to allow the formation of the measuring surface 12 and the polished edge 15. The measuring means 10 should not be too thin because when compressive forces exercised in the plane of a thin plate, it will tend to dent and be distorted in much the same way as a long, thin, axially loaded pillar. - The color density of printing ink printed on. a sheet was measured using: an "SOS-40'H digital reflection densitometer commercially available from CONSAR Corporation of Garland, Texas. The color density readings of process I yellow" longitudinally and across the printed sheet are set forth in Fig. 10. It is noted that side color adjustment is within a very narrow area and that length adjustment is also very tight. Other process colors, namely magnet, cyan and carbon black were measured with equally good color control.

The data data schematically illustrated in Fig. 10; indicates that a uniform film is measured by the measuring means 10 on the surface 45 of the applicator roller 40. It has been observed that forces required to operate a printing press with the above-described dyeing system do not differ significantly from the force required to drive printing presses equipped with conventional dyeing devices. However, as explained above, all ghost representations on are removed. the surface of the applicator roll 40 moving from the plate P1 towards the inlet side of the reservoir R and a fresh paint film is metered out and delivered to the pressure plate P1 at each revolution of the applicator roll 40. Thus ghost representations are eliminated. The measuring means 10 and 10 'manufactured and supported, as described above, are further capable of measuring. a film that is sufficiently thin and uniform enough to color the printing plate to achieve very high quality multicolor printing. The color density can be changed immediately by simply adjusting the position of the stop screw 74, which is adjusted on. distance. The sizing edge 15 of the sizing means 10, when said edge is properly formed, causes lint and other foreign material in the ink to be removed from the orifice or opening formed between the sizing means 10 and the surface of the applicator roller 40. To perform this function, the front or counter surface 12, against which the roller surface 45 moves, plays an important role. The measuring surface 12 forms above the edge 15 a barrier, against which the excess paint on the applicator roller 40 strikes, and creates a turbulence area as described above. Since the high pressure area is formed immediately before the movement of the paint past the polished edge 15, lint and other material will tend to be removed from this area if a low pressure path is provided in the reservoir R. The reservoir R is preferably at atmospheric pressure.7 It has been observed that so as long as the mating surface 12 is maintained in a position within about 500 on either side of a radius of the roller 40, which radius passes through the polished edge 15, lint and foreign material accumulate not appreciably adjacent to the polished edge 15. However, the tendency of foreign material to increase collects adjacent the edge 15 as the mating surface 22 is moved toward the top of the swelling 120. The measuring surface 12 is thus also held at an angle in order to maintain a turbulence area in the reservoir R adjacent to said surface. It should further be noted that the care of the abrupt surface 12 substantially radially prevents the emergence of hydrokinetic or hydrodynamic forces which would create a hydraulic pressure wedge which would tend to lift the polishing element 15 and thereby cause the thickness of the paint film 150 to vary as the surface speed of roll 40 changes. The edge 15 is thus hydrostatically supported by the roller surface 45 with ink.

From the foregoing, it will be apparent that the ink measuring means 10 and the ink measuring means 10 'when coordinated with the applicator roller 40 fulfill the above-listed objects of the invention.

It should furthermore be clear that other and further embodiments of the invention can be developed without departing from the scope of the invention as defined in the following claims.

Claims (7)

, 78028 84-2 26 _ Patent claim A method of forming a thin film of ink of uniform thickness on a resilient roller surface (44), wherein. an excess of ink is applied to it. a portion of the surface of the roller (40) which here is an ink film of irregular thickness, characterized by a combination of the steps of locating a measuring means (10 ') having a measuring edge (25) and a trailing edge, in printing relation to the resilient valeytan so. printing ink carried by the resilient roller surface strikes a substantially flat measuring surface (24) on the measuring means (101) adjacent the discharge edge (25), to act on both the measuring edge (25) and the trailing edge (at the intersection between 26 and 28a) in a direction substantially radially relative the resilient roller (40) for influencing both the beading edge and the trailing edge to the depressed relationship with the resilient roller surface and locating the beading edge (25) so that it is pressed -in the resilient roller surface a distance greater than the distance by which the trailing edge pressed into the resilient. the rolling surface, and to influence the mating edge (25) into the resilient rolling surface so. that the thickness of the ink film on the resilient roller surface which passes the mating edge of the mating member is reduced to a minimum thickness and - begins to increase in thickness when the force acting on the mating edge is pressed to the resilient member. the roller is increased. - 2. Ink measuring device for applying ink to. a printing plate (P ') in a printing press, to which an excess of ink is applicable. the surface of a mold roll (40) having a resilient surface (44) and the ink is callable to form a thin film of controlled thickness, characterized by the combination that the apparatus comprises the mold roll (40) having the resilient roll surface affected to pressure ratio to the pressure plate, a resilient. foreclosure means (10 '), a polished support surface (26) on. the resilient discharge means, a foreclosure surface. (24) on the resilient foreclosure means, a third surface (2Ba) on the resilient foreclosure means, that the discharge surface (26) and the foreclosure surface (24) intersect via a tip to form a releasable discharge edge (25), that the surface (26) and the third surface (28a) intersect at a tip to form a resilient trailing edge, a support device supporting the resilient dispensing means (10 ') for depressing the resilient the resilient edge (25) and the resilient trailing edge inside the resilient roller surface (44), that the support device is arranged to locate the resilient foreclosing means (10 ') so that the resilient deflecting edge (25) is pressed into the resilient roller surface (44) a distance at least as large as the distance by which the resilient trailing edge is pressed into the resilient roller surface, that the support device is arranged to resiliently support the resilient member (10 ') in a direction radially relative to the forming roll to allow movement of the resilient measuring edge (25) relative to the geometric axis of the forming roll and that the support device is arranged to support the resilient measuring edge (25) to prevent movement of the resilient measuring edge in a direction tangential to the forming roll, for applying an excess of ink to the resilient roller surface (44), which carries an ink film of irregular thickness after contacting the printing plate, and a device for causing the mold roll (40) to rotate to move the excess ink so that it strikes the mating surface (24). Apparatus according to claim 2, characterized in that the support device comprises a device for adjusting the angular relationship between the measuring surface (24) and a radial line extending through the resilient measuring edge (25). 4. Apparatus according to claim 2, characterized in that the support device comprises a device for adjusting the indentation of the resilient measuring edge (25). 5. Apparatus according to claim 2, characterized in that the discharge surface lies in a plane which intersects a radial plane at an angle of less than 300. " Apparatus according to claim 2, characterized in that the third surface (28a) lies in a plane which is set at an angle of at least 500 relative to a projection of the plane in which the support surface (26) lies. 27-8028 84-2 28 7. An apparatus according to claim 2, characterized in that the resilient foreclosure means comprises a hard, resilient, elongate strip having an upper surface and a lower surface, that the foreclosure surface (24) extends between and intersects the upper and lower surfaces, that the lower surface (28) of the elongate strip has a recessed area formed therein, that the recessed area (27) has a depth of at least 0.51 mm and that the third surface (28a) defines the polished support surface (26) on the resilient measuring edge (25) opposite the side of the polished support surface, that the third surface (28a) slopes relative to the polished abutment surface at an angle of at least 50 ° to form a resilient trailing edge which is spaced apart. from the compliant. the measuring edge (25), and that the support device engages with the hard, flexible, elongate strip to form a cantilevered beam with the measuring surface (24) on. the end of the cantilever beam.