US2573336A - Inking mechanism - Google Patents

Description

Oct. 30, 1951 R. H. HoLMwooD INKING MECHANISM Filed Sept. 5, 1947 IIIK llll Il IIIHIIIIIIIII INVENTOR A. H. HOZMWOOD BY 6. AGENT Patented oct. 3o, 1951 mmc MEcnANlsM Richard H. Holmwood, Binghamton, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application Septembe 3, 1947, Serial No. 771,919 l Claim/s (Cl. lol-364) This invention relates to printing machines, and, more particularly, to means for inking in connection with high speed rotary printing de.

vices having intaglio print cylinders.

High speed printing mechanisms employing rotating print cylinders frequently require complicated inking mechanisms in order to obtain perfect print impressions. When intaglio print cylinders, i. e. rotogravure devices, are employed,

it is essential that the ink be supplied to the print cylinder with suilicient pressure to be forced into the indentures of the cylinders periphery. Closed ink fountains wherein ink is pumped with high pressure against the print cylinder have been utilized, or arrangements such as that shown in U. S. -Patent 2,376,620 have been used. 'I'hese devices suffice for ordinary requirements; however, when low viscosityv inks, so chosen for their quick drying properties, are used, certain difllculties are encountered; as for example, escaping of ink and contamination of the printing machine and paper stock. n

It is an object of this invention to provide an improved ink fountain of simple construction and arrangement of parts suitable for use Awith any high speed intaglio print cylinder mechanism.

It is a further object of this invention to provide an improved ink fountain for high speed intaglio print cylinders wherein the ink pressure is substantialy dependent upon the rotation of the said cylinder.

It is still a further object of the invention to provide an improved ink fountain of simple arrangement for supplying ink to an intaglio print cylinder wherein the ink pressure is ineffective to cause ink to escape from the immediate path of rotation of the said cylinder to other parts of the mechanism.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of examples, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 illustrates a partial sectional view of the ink fountain mechanism.

Fig. 2 is a detail view of a valve and its control part of the top of an ink reservoir Il, and contains an entry port I5, from which ink ows into a cavity I6 extending across the cylinder between the cylinder II and the top surface of the plate I3. Ink I1 is supplied from the reservoir I4 by way of an intake I 8 of a pump I! (outside the reservoir) through a pipe 20 to a.' rotary valve 2| (see also Fig. 2) from which another pipe 22 connects with the port I5. The valve 2l is adjustable so that a part of the ink may be by-passed through a pipe 23 and returned into the reservoir Il by a port 24, thereby regulating the quantity of ink supplied to the cylinder II independently of the pump I9. 'Ihe valve 2| is manually adjusted to regulate the ink flow by a knob 25 which is mounted on the outside of the reservoir Il, which also holds a dial 26 for indicating the valve setting. A shaft 21 carries a platen 28 which coacts with the'print cylinder II to provide a backing for a web 29 which is printed upon as the cylinder II is rotated. A doctor blade 30 is provided to remove excess ink from the peripheral surface of the print cylinder II before it encounters the web 29, the excess ink being returned into the reservoir I4 via an exit port 3l.

Ink is pumped from the reservoir I4 by the pump I9 through the pipe 2II, the valve 2I, the pipe 22, and the port I5 into the cavity I6, the quantity of ink being gradually increased by manually adjusting the valve 2l, as the cylinder II is accelerated to its final speed of rotation, so that the cavity I6 remains substantially iilled. The cylinder I I and the arcuate plate I3 are ar-` ranged so that their axes of curvature lie in a common plane represented by a line C-C, which cuts the surfaces of these members at the points :c and y respectively. The distance between a: and y is relatively small, its dimension being governed by the quantity of ink required to wet the surface of the cylinder and by the speed ofrotation of the cylinder II, and in one particular design of ink fountain actually was .031 inch. The radius of curvature of the plate I3-is larger than the radius of the cylinder II, the most effective ratio being found to be approximately 1.5 to 1 respectively for the plate to cylinder, and in the design referred to above the arcuate plate radius was 1.7 inches while the radius of the cylinder was 1.2 inches :.tpproxirxiately.` The plate I3 extends beyond the line` C-C in the direction of rotation of the cylinder II, the most effective distance being found to be approximately, 50% of the radius of the cylinder II, and in the designreferred to was .5625 inch. It is to be noted that the above ratios and dimensions were determined experimentally for a speed of operation of the print cylinder I I of 1000 R. P. M., or a printing speed of approximately 600 feet per minute.

It has been determined experimentally that the pressure at m-l (Fig. 1) is greater than the pressure at m-Z is greater than the pressure at 11n-'3, and that the pressure at p-Z is greater than the pressure at p-I; consequently, since the cavity I 6 ismaintained filled with ink (the quantity of ink being substantially constant), it follows that these pressure relationships are brought about by the arrangement and relative motion of the cylinder II and the plate Il affecting the flow of ink in the cavity I6, wherein the velocity of the ink at m-I is less than the velocity at m-2 is less than the velocity at vnf-3, and -that the velocity at p-2 is l'ess than the velocity at p-I. It is therefore apparent that the subject device functions in a manner according to Bernoullis theorem, whereby the resultant pressure of the ink at a point p-2 (see Fig. 1) is equal to the static head delivered by the pump I9 (at the entrance to the cavity I6) plus the velocity head acquired by the ink due to the rotation of the cylinder II. Consequently, the ink pressure at a point p-2 is actually derived, for the most part, from the rotation of the cylinder I I since the static head is almost negligible. It is obvious that as the speed of rotation of the print cylinder is increased the pressure at a point p-2 will be increased so that, within limits, the ink will be forced into the indentations of the print cylinder with increasing pressure as the speed of rotation of the cylinder is increased, thereby effectively permitting satisfactory print impressions to be made at very high speeds.

It is obvious that the print cylinder II may be replaced by another cylinder, serving as an inking cylinder, to deliver ink to a print cylinder in the more conventional methods employed in rotary printing machines.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. An inking mechanism comprising a rotating cylinder, and a receptacle having an arcuate surface of substantially greater radius mounted in ink feeding relationship parallel thereto with the said surface disposed eccen- -trically adjacent to but spaced from the peripheral surface of the said cylinder, an ink inlet formed by the said cylinder and said receptacle, an ink outlet formed by the said cylinder and said receptacle, the said cylinder and said receptacle further being arranged to form an ink passageway between the said inlet and said outlet, means for causing ink to ilow into the said inlet through the said passageway, and out of the said outlet, the said outlet having a greater opening than the said passageway and a lesser opening than the said inlet.

2. An inking mechanism comprising a rotating cylinder, and a receptacle having an arcuate surface of substantially fifty percent greater radius mounted in ink feeding relationship eccentrically adjacent to but spaced from the said cylinder thereby mutually providing a ow cavity having an inlet of a predetermined crosssectional area, an orifice having a lesser crosssectionai area at a predetermined distance from said inlet in said cavity, and an outlet having a cross-sectional' area lesser than the said inlet and greater than the said orifice, the said outlet being spaced a distance from the said orifice equal to one-half the radius of the said cylinder in the direction of rotation of the said cylinder,

whereby the pressure of ink flowing in the said.

cavity against the said cylinder varies directly with the speed of rotation of the said cylinder.

3. An ink fountain for a printing machine comprising, a rotatable ink cylinder, a container for holding ink, an ink receptacle associated with and forming a closure for the said container, the said receptacle having an ink inlet at one end and an ink outlet at the other end, an arcuate surface upon the said receptacle extending from the said inlet to the said outlet, the said surface being of substantially greater radius than the said cylinder and disposed eccentrically adjacent to but spaced from the said cylinder in ink feeding relationship so that a flow cavity is mutually formed thereby, the said cavity having a maximum cross-section at the said inlet. a lesser cross-section at the said outlet, and a minimum cross-section therebetween; a pump connected between the said container and the said inlet for supplying ink to the said receptacle to fill the said cavity thereby establishing a static head, and means to rotate the said cylinder, whereby the final pressure head of the ink in the said cavity is equivalent to the sum of the said static head and the velocity head derived from the rotation of the said cylinder.

4. An ink fountain for a printing press comprising, a rotatable ink cylinder, a container for holding a supply of ink, an ink receptacle associated with and forming a closure for the said container, the said receptacle having an ink inlet at one end and an ink outlet at the other end, an arcuate surface upon the said receptacle between the said inlet and the said outlet, the said surface being of substantially greater radius than the said cylinder and disposed eccentrically adjacent to but spaced from the cylinder in ink feeding relationship so that a flow cavity is formed mutually thereby, the said cavity being of maximum cross-section at the said inlet, of

lesser cross-section at the said outlet, and of minimum cross-section at a point therebetween nearer the said outlet; a pump between the said container and the said inlet for supplying ink to the receptacle and for building up and maintaining a static head of ink in the said cavity, means for rotating the said cylinder to set up in the said cavity a velocity head combiningy with the said static head to feed ink under pressure to the cylinder at the said outlet, and a valve between the said pump and the said inlet for regulating the flow of ink to the said receptacle.

5. An ink fountain for supplying ink to a rotating cylinder of a predetermined curvature comprising an arcuate member of lesser curvature partially surrounding the cylinder in ink feeding relationship spaced from and arranged with the said cylinder -to mutually form therewith an elongated ink cavity having an inlet and an outlet and a constriction located intermediate thereof, the cross-sectional area of the outlet being less than that of the said inlet and parallel thereto with the said surface dispQsed 'I5 more than that of the said constriction.

6. An ink fountain for a printing machine comprising, a rotatable ink cylinder, a container for holding ink, an ink receptacle associated with and forming a closure for the said container, the said receptacle having an ink inlet at, vone end and an ink outlet at the other end, an arcuate surface upon the said receptacle extending from the said inlet to the said outlet, the said surface being of substantially greater radius than the said cylinder and disposed eccentrically adjacent to but spaced from the said cylinder in ink feeding relationship so that a flow cavity is mutually formed thereby, the said cavity having a maximum cross-section at the said inlet, a lesser cross-section at the said outlet, and a minimum cross-section therebetween.

7. An ink fountain for a printing press comprising, a rotatable ink cylinder, a container for holding a supply of ink, an ink receptacle asso ciated with and forming a closure for the said container, the said receptacle having anvink inlet at one end and an ink outlet at the other end, an arcuate surface upon the said receptacle between the said inlet and the said outlet,A the said surface being of substantially greater radius than the said cylinder and disposed eccentrically adjacent to but spaced from the cylinder in ink feeding relationship so that a ow cavity is formed mutually thereby, the said cavity being of maximum cross-section at the said inlet, of lesser cross-section at the said outlet, and of minimum cross-section at a point therebetween nearer the said outlet.

8. A n ink fountain for a printing machine comprising, a rotatable ink cylinder, a container for holding ink, an ink receptacle associated with and forming a closure for the said container, the said receptacle having an ink inlet at one end and an ink outlet at the other end, an arcuate surface upon the said receptacle extending from the said inlet to the said outlet,

the said surface being of substantially greater.

radius than the said cylinder and disposed eccentrically adjacent to but spaced from the said cylinder in ink feeding relationship so that a flow cavity is mutually formed thereby, the said cavity having a maximum cross-section at the said inlet, a lesser cross-section at the said o'utlet, and a minimum cross-section therebetween; means for supplying ink to the said receptacle to ll the said cavity thereby establishing a static head, and means to rotate the said cylinder, whereby the final pressure head of lthe ink in the said cavity against the said cylinder is equivalent to the sum of the said static head and the velocity head derived from the rotation of the said cylinder.

9. An ink fountain for a printing press comprising, a rotatable ink cylinder, a container for holding a supply of ink, an ink receptacle associated with and forming a closure for the said container, the said receptacle having an ink inlet at one end and an ink outlet at the other end, an arcuate surface upon the said receptacle between the said inlet and the said outlet, the said surface being of substantially greater radius than the said cylinder and disposed eccentrically adjacent to but spaced from the cylinder in ink feeding relationship so that a iiow cavity is formed mutually thereby, the said cavity being of maximum cross-section at the said inlet, of lesser cross-section at the said outlet, and of minimum cross-section at a point therebetween nearer the said outlet, means coacting with the said container and the said inlet for supplying ink to the receptacle and for building up and maintaining a static head of ink in the said cavity, means for rotating the said cylinder to set up in -the said cavity a velocity head combining with the said static head to feed ink under pressure to the cylinder at the said outlet, and a valve for regulating the dow of ink to the said receptacle. p

10. An hiking mechanism comprising a rotating cylinder, and a receptacle having a curved surface mounted in ink feeding relationship thereto with the said surface adjacent to but spaced from the said cylinder thereby mutualiy forming an elongated i'low cavity, said cavity providing an ink inlet at one extremity and an ink outlet at the other extremity, the said inlet having a greater cross-sectional area than the outlet and a portion of the cavity therebetween having a cross-sectional area. less than either, whereby the pressure of ink in the said cavity flowing against the said cylinder at the said outlet varies directly with the speed of rotation of the cylinder.

RICHARD H. HOLMWOOD.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 374,644 Turner Dec. 13, 1887 846,131 Munz Mar. 5, 1907 1,293,305 Bechman Feb. 4, 1919 1,644,723 Halliwell Oct. 11, 1927 1,861,142 Scherrer May 31, 1932 2,039,992 Harold May 5, 1936 2,154,544 Taylor Apr. 18, 1939

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