US2633796A

US2633796A - Printing means using electric fields

Info

Publication number: US2633796A
Application number: US529595A
Authority: US
Inventors: Ford C Pethick
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1944-04-05
Filing date: 1944-04-05
Publication date: 1953-04-07
Anticipated expiration: 1970-04-07

Description

April 7, 1953 F. c. PETHICK 2,633,796

mmm MEANS USING ELECTRIC FIELDS Filed April 5, 1944 3 Sheets-Sheet l INVENTOR 46 F812 D C. PEI-max.

F511- BY ATT RNEY April 7, 1953 g, PETHICK 2,633,796

PRINTING MEANS USING ELECTRIC FIELDS Filed April 5, 1.944 3 Sheets-Sheet 2 a o. 3 w I ATT 0 EY A ril 7, 1953 F. c. PETHICK 2,633,796

PRINTING MEANS USING ELECTRIC FIELDS Filed April 5, 1944 3 Sheets-Sheet 3 IO a 20 I/Z 6 FLEJEJ- Ella-LE1- INVENTOR Hm 9 CT Prrmck mNEY Patented Apr. 7, 1953 PRINTING MEANS USING ELECTRIC FIELDS Ford C. Pcthick, Englewood, N. J., assignor to R. Hoe & 00., Inc., New York, N. Y., a corporation of New York Application April 5, 1944, Serial N 0. 529,595

This invention relates to a novel method and means for printing, and more specifically refers to depositing ink through the influence of an electric field.

The invention contemplates as its principal object, the provision of a method and means for printing which does away with the necessity of inking type before an object can be printed therefrom.

Another object of the invention is to provide a method and means for transferring ink directly from an ink supplying mechanism to the material to be printed.

Another object of the invention is to provide a new and improved mechanism from which ink can be transferred directly to the material to be printed.

Another object of the invention is to provide a means to limit the portion of the web or sheet on which ink may be deposited.

Still another object of the invention is to provide a new type of printing plate.

Other and further important objects of the invention will become apparent from the following description and the appended claims.

In accordance with the invention, as herein shown, a travelling web of paper is passed between a plate carrying form cylinder and an ink supplying mechanism. Due to forces set up by an electric field, ink is removed from the ink supplying mechanism and deposited on the web in accordance with a design carried by the form cylinder. For a more complete understanding of the invention, reference should be' had to the accompanying drawings in which:

Figure 1 is a perspective view of a portion of a printingmachine embodying the principles of the invention;

Figure 1A is an electrical diagram showing a method of supplying electric power to the printingunit shown in Figure l; Figure 2 is an enlarged cross sectional view of a portion of the printing unit shown in Figure l; Figure 3 is a fragmentary view similar to a portion of Figure 2 and depicting a modified form of printing plate; 7

Figure 4 is a perspective view of portions of a 3 Claims. (01. 101-212) Figure 9 is an enlarged view of the ink supplying mechanism shown in Figures 8 and 10; and

Figure 10 is a view, showing a further development of the form of the invention depicted in Figure 8.

Referring to the drawings, the invention has been shown in one form in Figures 1, 1A and 2 as applied to a web printing machine comprising a form or type cylinder H), which cooperates with a guide roller ll about which a sheet or web 12 of paper or other suitable material is led. The form cylinder I0 is rotatable on a shaft l3 and carries a printing form or plate l4 having a design formed by raised, sharp-edged type 15 intermingled with depressions IS. The plate M may be constructed according to usual practices, except, that the letters, numerals, and other designs appearing on the surface thereof, should be direct reading in place of reversed as is the practice with present day newspaper and magazine plates.

As illustrated in Figure 1, the web 12 passes over the guide roller H and about the lower portion of the form cylinder l0. As illustrated, a surface I9 of the web I2 is in contact with the form or plate 14, while a surface 20 of the web is exposed.

A means for printing on the exposed side 20 of the web l2 has been provided adjacent to the exposed side thereof, and includes a plurality of atomizer type ink supplying mechanisms 2|, each having an enclosed ink reservoir 22, and an insulated ink supply tube 23. Preferably ink is caused to rise in the tubes by means of air pressure supplied to the reservoir by way of an air duct 24. An air blast from insulated nozzles 25 cooperates with each insulated ink tube, to atomize the ink and to produce an ink mist. A means 21 for electrifying the ink spray or mist is positioned directly in front of the atomizer 2|, and in the embodiment of the invention illustrated in Figures l, 1A- and 2, comprises a fine wire 28 positioned parallel to the axis of the cylinder Ill and located parallel to and between a .pairof parallel cylindrical rods 29. A high voltprinting machine showing a modifledfonn-of the invention; s Figure- 5 is an enlarged cross sectional view taken through the line 5-5 of Figure 4, and lookingin the direction-of the arrows;

Figure 6 is a view similar to Figure 5, but

showing .theformpcylinder in a slightly advanced position;

vFigure 7..is a fragmentary cross sectional view showing another modified form of the invention; Figure 8is a yiew showing a printing machine equipped. with .;a modifled..fprm.;of.ink supplying mechanism;

age source oi -direct currents!) is connected between the wire 28 and rods 29, the wire 28 pref- :erably being charged positively with respect to the rods 29 which may be maintained at ground potential.

As particles of ink in the ink mist pass the highly charged wire '28, they acquire a positive electrical charge and form a positively charged ink mist 30a. A shield 3|, having a flared portion 32, is positioned concentric with the form cylinder 10 and preferably is spaced one-eighth to one-half an inch therefrom. The atomizer 2| .and the electrifying mechanism 21 are positioned :sothat, the stream of electrified ink mist 30a is .:dir.ected toward. the. space 33 between. the exposed side 20 or the web l2, and the shield ll.

3 The shield 3| is highly charged positively with respect to the form cylinder I5, which may be maintained at ground potential.

One method of electrifying various portions of the equipment is shown in Figure 1A wherein the wire 28, and shield 3| are shown connected to a positive terminal 34 of the high voltage electrical source 30 by a conductor 35. The negative terminal 33 of the source 30 is grounded as at 39. Rods 29 and the cylinder 20 are grounded by conductors 40 and 4| respectively.

The high voltage which is applied between the positively charged shield 3| and the negative form cylinder It causes a strong electric field to be formed therebetween. As the positively charged particles of the ink mist 36a enter this electric field, they are repelled by the positive shield 3| and attracted by the negative plate $4, with the resultthat ink is deposited on the lower surface 25 of web I2 in accordance with the design carried on the plate I4. Since any face 42 of the type or other design I5 is closer to the shield 3| than are the bottoms of the depressions of the web I2 and a new design on the plates I4 are rotated into the electric field defined by the shield 3|, and this results in the web I9 being printed as it passes over the form cylinder I5.

Figure 3 shows amodified form of printing plate I4 in which the depressions I6, between the raised portions I5 of the type are filled with an insulating material 48 having a high dielectric constant. Placing this material in the depressions I6 is equivalent to increasing their depth, and helps to concentrate the electric field, and thus the ink on the area of the web opposite the face 42 of the type or other design. The modified form of plate I4 shown in Figure 3 of course may be substituted for the plate I4 shown in Figure 2.

-A modified form of theinvention is illustrated in Figures 4, 5 and 6 wherein the web I2 is forwarded by being passed underneath the roller I i and then over the top of the form cylinder I0. An ink supplying mechanism 53 is located close to and above the rotatable form cylinder Ill. The cylinder 15 and its shaft I3 carry a concentric cam 54, having two low portions 58 and two high portions 59. A cam follower 60 engages the cam 54 to control'an electric switch 6|, the function of which is hereinafter described. The ink supplying mechanism 53, supported on proper insulators (not shown), may consist of a hopper or V-shaped metallic box 5| having a cover 62, and an opening or slot 63 atthe bottom thereof, whereby ink mist 64, produced in the ink supplying mechanism 53, may bedeposited on the face 2|) of the web I2. Preferably the box 5| may contain a plurality of ink spray nozzles 65 arranged to produce the ink mist 54.

Pipes

61 and 68, containing proper insulating joints (not shown), may be employed to supply air and ink to the mist producing nozzles. Due to the force of gravity and the air pressure produced in the box 5| by the spray nozzles, the ink mist 54 is expelled through the opening 53. As best illustrated in Figures 5 and 6, the opening 63 is equipped on both sides with sharp edged troughs 89. running lengthwise of the box 5|, which through connecting pipes (not shown), carry away any liquid ink which may form on the inside of box 5|. Opening 53 is also equipped with a knife shaped electrode I2 supported at 13, running lengthwise of the opening 63, and preferably spaced equi-distant between the two troughs 69. Preferably a high potential source of directcurrent 36 is controlled by contactor I4. The metallic box 5| of the ink supplying mechanism 53 may be connected to one contact 15 of the contactor I4 by means of electrical conductor I8, and the other contact of the contactor 14 may be connected to the positive terminal 34 of source 30 by conductor 85.

The negative terminal of source 30 and the form cylinder it are grounded by means of conductors 39 and 4| respectively. Solenoid 8|, which operates the movable contact of contactor I4, is connected to one terminal of a control power source 52 by means of a conductor 83 and to one terminal of the switch 5| by a conductor 84. The other terminal of the switch 6| is connected to the second terminal of the control power source 82 by a conductor 85. The low portions 58 of the cam 54 are positioned opposite the margin bars 88, located between the edges of the two plates I4. Thus when the cam follower 50 follows into the low portions 53, the switch BI is opened and the solenoid 8| of the contactor I4 is deenergized, with the result that the high potential source 35 is disconnected from the ink supplying mechanism 53 during the period while the margin bars 88 pass the opening 53 in the box 5|. This assures that irregularities caused by the margin bars 88 and the edge of the plate I4 will not appear as printing on the web I2. It will be understood that an electronic contactor having proper grid control can be substituted for the magnetic contactor 14. As in the previously described embodiment of the invention, ink from the ink supplying mechanism is deposited on the side 20 of web I2 opposite from the side I9 which contacts the form I4 and the electric field which is established between the ink supplying mechanism 53 and the form cylinder in controls the particles of ink mist 64, with the result that ink is deposited on the web I2 in accordance'with the design carried by the form or plate I4. The particles of the ink mist 64 which leave the positively charged ink supplying mechanism 53 carry a positive electrical charge and thus are repelled by the box 5| and are attracted by the negatively charged plate I4 and cylinder I0.

As the form cylinder IIJ rotates to carry the plate I4 past the opening 63 in the box 5|, the electric field which exists between the box 5| and the face 42 of the form I4 varies as the design on the form or plate varies. This phenomenon is illustrated in Figures 5 and 6 where the design carried on the plate I4 is shown in two different positions with respect to the knife 12 and opening 63. I

A further modification of the invention is illustrated in Figure 7 in which a plurality of atomizers 2| (only one of which is shown), have parts formed from insulating material similar to the atomizer 2| shown in Figure 2, and spray atomized ink past the positively charged wire 28 located between the rods 29, which are similar to the wire 28 and the rods 29 shown in Figure 2. The ink mist 35a which is electrified after passing the wire 28, passes between a positively charged knife type electrode 92and the negatively charged printing plate 14. The electric lines of force existing between the electrode 92 and the plate it controls the ink mist so that it is deposited on the exposed face 2c of the web 12 in accordance with the design carried by the plate Id. A collection system consisting of an exhaust pipe a reclamation tank 9:. having baffles s5, and a suction pipe at, has been provided in order to remove any excess ink mist 30a which is not deposited on web l2.

A still further modification of this invention is shown in Figures 8, 9 and in which another type of ink supplying mechanism its is employed. The web it is passed over a roller II and under a form cylinder it while electrical energy is supplied from the high potential source 3?} and the control source 82 in a manner similar to that shown in Figure 4. One of the differences being that the switch 61 is located above the cam 54, and that the ink supplying mechanism Hit is positioned below the form cylinder It. The ink supplying mechanism ice is connected to the positive terminal 34 of high voltage source and is insulated from round by post type insulators Iiil. A motor 52 drives a pair of rollers M3 by means of belt its and pulleys 195. The two large rollers Hi3 and a small roller H16 are mounted on a frame its in the form of a triangle and carry a wide belt I07 having bristles I08 protruding from the outer surface thereof. The lower part of the rollers Hi8 and the portion of the belt Hi1 stretched therebetween are immersed in a tray H I containing a supply of ink. As the belt I6! travels over the three pulleys it carries ink from the tray II I to a point I I2 close to the exposed surface 2!! of the web 12. The high potential electric field which exists between the roller I06 and the plate I4 carried by cylinder i8 transfers ink from the bristles I68 to the exposed surface 20 of the web :2. Since the small particles of ink on the ends of bristles I88 are positively charged, they are repelled by the positively charged roller H16 and attracted by the negatively charged plate It and thus the web [9 is printed in a manner similar to the method hereinbefore described.

The embodiment shown in Figure 10 is similar to that shown in Figures 8 and 9 except that a plurality of separate ink supplying mechanisms MA, [MB and I680 are spaced around the periphery of the plate cylinder [0. Each ink supplying mechanism is associated with a switch 61A, BIB, and 610, a contactor MA, MB and 140, a high potential power source 36, and a control power source 82; all being similar to those previously described. By means of these mechanisms it is possible to apply more than one application of ink to the web as it passes over the form cylinder 10. For example, as the web 12 passes around the lower half of form cylinder I0, it receives an initial printing as it passes by the roller IDEA of ink supplying mechanism of 100A, and as the same portion of the web passes ink supplying mechanism 18313 and IBIC it receives a second and third printing. It will be understood that the same design is printed by all three ink supplying mechanisms with the result that the design printed will be more intense than a design formed by one printing. The switches BIA, 61B and GIC cooperate with the ink supplying mechanisms WA, 18813 and 1000 respectively to deenergize their respective high voltage source at the instant that the margin bars 88 pass by the rollers IDEA, IOSB and 106C respectively.

It will be understood that the invention may be embodied in other specific forms, as for example, it can be arranged to print sheets in place of a web, without departing from the spirit or essential attributes thereof, and it is therefore desired that the illustrated embodiments be considered in all respects as illustrative and not restrictive.

What I claim is:

l. A printing unit for printing on a sheet comprising in combination a form cylinder, a printing plate mounted on the form cylinder and arranged to contact one side of the sheet, at least one ink supplying mechanism, and a means for producing an electric field between the ink supplying mechanism and the plate; the said ink supplying mechanism comprising in combination an ink tray, a travelling belt having a multiplicity of bristles and being arranged to transfer ink from the said ink tray to a point adjacent to the side of the sheet which is not in contact with printing plate.

2. In a web printing unit comprising in combination a form cylinder having a design carried by a plate arranged to contact one side of a sheet of material, at least one ink supplying mechanism, and a means for producing an electric field between the said ink supply mechanism and the plate, and a means for deenergizing the electric field producing means when the edge of the plate is in the neighborhood of the ink supplying mechanism; the said ink supplying mechanism comprising in combination a tray, a travelling belt having a multiplicity of bristles and being arranged to transfer ink from the said ink tray to the point adjacent to the side of the material which is not in contact with the plate.

3. A printing unit for printing on a sheet or web and comprising in combination a form cylinder, a printing plate mounted on the form cylinder and arranged to contact one side of the sheet or Web, at least one ink supplying mechanism, and a means for producing an electric field between the ink supplying mechanism and the plate, the said ink supplying mechanism comprising in combination an ink tray, a traveling belt having a multiplicity of bristles capable of supplying ink in the form of small particles and arranged to transfer ink from the said ink tray to a point adjacent to the side of the sheet or web which is not in contact with the printing plate.

FORD C. PETHICK.

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

UNITED STATES PATENTS Number Name Date 767,684 Burdick Aug. 16, 1904 1,217,250 Wensel Feb. 27, 1917 1,763,731 Whittaker June 1'7, 1930 1,820,194 Huebner Aug. 25, 1931 2,224,391 I-Iuebner Dec. 10, 1940 2,408,144 Huebner Sept. 24, 1946 2,451,288 Huebner Oct. 12, 1948 FOREIGN PATENTS Number Country Date 214,669 Great Britain 1924