US3800743A

US3800743A - Materials application apparatus

Info

Publication number: US3800743A
Application number: US00119914A
Authority: US
Inventors: R Egnaczak
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1969-11-14
Filing date: 1971-03-01
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

Apparatus for coating materials onto a surface comprising a housing pivotally connected to a carriage, a chamber and applicator within the housing. The pressure of the applicator against the surface to be coated is adjusted by varying the pivot of the housing containing the applicator relative to the carriage. The entire apparatus is advanced automatically into and out of contact with the surface to be coated. An alternative embodiment with an extruder applicator is also disclosed.

Description

United States Patent [1 1 Egnaczak I 1 1 Apr. 2, 1974 MATERIALS APPLICATION APPARATUS [75] Inventor: Raymond K. Egnaczak, Williamson,

[73] Assignee: Xerox Corporation, Rochester, N.Y.

[22] Filed: Mar. 1, 1971 21 Appl. No.: 119,914

Related US. Application Data [62] Division of Ser. No. 876,646, Nov. 14, 1969, Pat. No.

[52] US. Cl 118/259, 117/l7.5, 1l8/DIG. 23, 118/241, 118/637 [51] Int. Cl. B056 1/06, B050 l/O8 [58] Field'of Search 118/DIG. 23, 637, 104,

118/203, 258, 259, 241, 242, 260, 268, 266, 50; l17/l7.5, 37 LE [56] References Cited UNITED STATES PATENTS 2,159,674 5/1939 Petersen 91/50 3,410,713 11/1968 Schneidereit... 117/37 2,770,215 11/1956 Knight 118/260 2,915,038 12/1959 Wallenberg 118/249 3,363,530 1/1968 Rice 95/89 3,561,400 2/1971 Smitzer... 118/637 3,298,305 1/1967 Noon 101/366 3,052,565 9/1962 Chinn et a1. 118/411 3,633,505 1/1972 Ferrari 118/258 2,856,848 10/1958 Pritchard 101/147 3,634,077 l/l972 Sullivan 96/14 3,354,867 1l/1967 Pomper et al. 118/104 2,874,674 2/1959 Hornbostel 118/113 3,179,536 4/1965 Martinck 117/102 2,649,758 8/1953 Cowgill 118/602 Primary ExaminerMervin Stein Assistant Examiner-Leo Millstein [57] ABSTRACT Apparatus for coating materials onto a surface comprising a housing pivotally connected to a carriage, a chamber and applicator within the housing. The pressure of the applicator against the surface to be coated is adjusted by varying the pivot of the housing containing the applicator relative to the carriage. The entire apparatus is advanced automatically into and out of contact with the surface to be coated. An alternative embodiment with an extruder applicator is also disclosed.

9 Claims, 4 Drawing Figures MATERIALS APPLICATION APPARATUS This is a division of application Ser. No. 876,646, filed in the United States, Nov. 14, 1969, now US. Pat. No. 3,609,029.

This invention relates to coating systems and in particular to a fluid extruder system.

Systems exist that require working with layers of fluids, especially viscous liquids, that must be uniformly applied to a surface for working on the surface. One such system improved by a uniform coating technique and by the invention herein is the photoelectrophoretic imaging process. A detailed description of this process is given in US. Pat. Nos. 3,384,565, 3,384,566 and 3,383,993. These patents disclose how to produce a visual image at one or both of two electrodes between which a photoelectrophoretic particle suspension is placed. The particle suspension is comprised of photosensitive particles suspended within an insulating liquid carrier. The particles appear to undergo a net change in charge polarity or a polarity alteration by interaction with one of the electrodes upon exposure to activating electromagnetic radiation. The theory of operation is that the particles have a net charge when suspended in the liquid carrier and are attracted to the electrodes under the influence of an electrical field placed between them. Mixtures of two or more differently colored particles can secure various colors of images. The particles will migrate from one of the electrodes under the influence of an electric field when struck with energy of a wavelength within the spectral response of the colored particles.

Since the disclosure of the basic processes, continuous imaging machines have been disclosed, for example, in US. Pat. No. 3,427,242. It becomes important to be able to supply uniformly thin layers of the imaging suspension to one of the electrodes in such automated devices in order to form the best possible images from the machine. I

It is also helpful in many instances to stress the suspension with a shear stress. This apparently improves the imaging qualities of the suspension.

Therefore, it is an object of this invention to improve fluid coating means. Another object of this invention is to improve means for uniformly coating liquids on a surface. Still another object of this invention is to extrude fluids onto a surface. Yet another object of this invention is to pre-stress fluids for application to a surface.

The invention herein is described and illustrated in a specific embodiment having specific components listed for carrying out the functions of the apparatus. Nevertheless, the invention need not be thought of as being confined to such a specific showing and should be construed broadly within the scope of the claims. Any and all equivalent structures known to those skilled in the art can be substituted for specific apparatus disclosed as long as the substituted apparatus achieves a similar function. It may be that other processes or apparatus will be invented having similar needs to those fulfilled by the apparatus described and claimed herein and it is the intention herein to describe an intention for use in apparatus other than the embodiment shown.

These and other objects of this invention are accomplished by employing a system for forcing fluids to a moving surface through an extruder mechanism adapted to supply a uniformly thin coating of the fluid on'the surface moving thereby. A smoothing means and a pulsed fluid manifold ensure the uniformity of the thin layer of fluid on the coated surface. These and other objects and advantages of this invention will become apparent to those skilled in the art after reading the description in conjunction with the accompanying drawings wherein:

FIG. 1 schematically represents an embodiment of this invention in conjunction with a photoelectrophoretic imaging system;

FIG. 2 is a close-up of the application member with portions broken away to show internal structure;

FIG. 3 is a fluid supply system shown, for example, for use in conjunction with the apparatus of FIG. 4; and

FIG. 4 shows an alternative embodiment of apparatus according to this invention.

There are certain terms of art used in conjunction with the photoelectrophoretic imaging process that should be defined. The injecting electrode is so named because it is thought to inject electrical charges into activated photosensitive particles during imaging. The term photosensitive for the purposes of this disclosure refers to the property of a particle which, once attracted to the injecting electrode, will alter its polarity and migrate away from the electrode under the influence of an applied electric field when exposed to activating electromagnetic radiation. The term suspension may be defined as a system having solid particles dispersed in a solid, liquid or gas. Nevertheless, the suspension used in the disclosure herein is of the general type having a solid suspended in a liquid carrier. The term imaging electrode is used to describe that electrode which interacts with the injecting electrode through the suspension and which once contacted by activated photosensitive particles will not inject sufficient charge into them to cause them to migrate from the imaging electrode surface. The imaging electrode is covered with a dielectric surface composed of a material having a volume resistivity preferably in the order of 10 or greater ohm-cm and a conductive member which is preferably a resilient material such as a conductive rubber used to give flexibility to the imaging electrode.

For photoelectrophoreticimaging to occur it is thought that these steps, (not necessarily listed in the sequence that they occur) take place: (1) migration of the particles toward the injecting electrode due to the influence of an electric field, (2) the generation of charge carriers within the particles when struck by activating radiation within their spectral response curve, .(3) particle deposition on or near the injecting electrode surface, (4) phenomena associated with the forming of an electrical junction between the particles and the injecting electrode, (5) particle charge exchange with the injecting electrode, (6) electrophoretic migration toward the imaging electrode, (7) particle deposition on the imaging electrode. This leaves an optically positive image on the injecting electrode.

The schematic representation of FIG. 1 shows a photoelectrophoretic imaging apparatus having an injecting electrode 1 with a coating of a transparent conductive material 2 such as tin oxide over a transparent glass member 3. Such a combination is commercially available under the name NESA glass from Pittsburgh Plate Glass Company of Pittsburgh, Pa. However, other elcc trically conductive transparent coatings over transparent substrates are suitable for use herein. Imaging sus pension is applied to the surface of the injecting electrode by the extruder mechanism 4 where it is carried because of the motion of the injecting electrode to the imaging area between the injecting electrode and the imaging electrode 5.

The imaging electrode 5 has a surface 6 composed of a dielectric material sleeve and a conductive substrate 7 which is preferably a resilient material such as an electrically conductive rubber. The imaging electrode prevents sufficient charge injection into the particles to cause them to migrate from its surface. The imaging electrode is connected to a potential source 8 while the injecting electrode is shown as electrically grounded to give the necessary field affect at the imaging area between the two electrodes. An exposure mechanism including an illumination means I0 and a lens III presents a flowing image of the object I2 at the image area which coincides with the optical image plane. The image is moving at the imaging area at the same rate as are the moving surfaces of the injecting and imaging electrodes. The image thus formed at the imaging area is carried by the injecting electrode to the transfer station where it is transferred to a support sheet 15. The transfer roller 16 is coupled to an electrical source 17 providing a field with the injecting electrode opposite in sign from that at the imaging area. A cleaning brush I8 removes residual particles from the surface of the injecting electrode so that the imaging cycle may be completed with other images being formed.

The extruder mechanism 4 is mounted on a brace 20 which has rails 21 therein. A stationary bracket 22 mounts an air cylinder 24 having an air inlet 25 and an air intake hose 26. The piston 27 of the cylinder, through the crank arm 28, moves a rack 29 and pinion 30 to engage and disengage the extruder in suspension application interface with the injecting electrode surface 2. The rack moves the extruder mounting 31 in the rails 21 of the brace 20.

The interfacing portion 32 of the extruder is pivoted about a pin 33 and is preset with an interface pressure adjusting screw 34 and an adjusting spring 35. The interfacing member shown in FIG. I is a smoothing rod 36 which can be grooved, wound wire, knurled, or smooth surfaced to present a uniformly thin layer of suspension on the injecting electrode surface.

FIG. 2 is a closeup of the interfacing portion 32 of the extruder with the side wall removed so that internal parts are seen. The suspension is pulsed in through the inlet tube 40 into a chamber 42 enclosed by the smoothing rod 36, a frame member 43, a coater blade M and a scraper blade 46. The smoothing rod 36 is driven with outboard oversize drive wheels pressed against the ends of the injecting electrode cylinder so that it moves when the wheels are in contact with the cylinder. A coater blade 44 limits the amount of suspension traveling around the periphery of the smoothing rod 36 for contact with the injecting electrode surface 2. The scraper blade 46 prevents used imaging suspension from contaminating the suspension held in the chamber 42 while preventing the suspension within the chamber 42 from leaking out of that chamber. The chamber 48 of the interfacing portion 32 of the extruder is a vacuum chamber for removing suspension materials within its housing walls 50. The materials are carried through the outlet 52 for removal from the vicinity of the injecting electrode and the imaging systern. The drive wheels are larger in diameter than is the smoothing rod 36. The difference in diameter determines the clearance between the smoothing rod 36 and the surface 2. The thickness of the coated fluid on the surface is more or less equal to the clearance.

FIG. 3 demonstrates the gas and suspension supply system for the extruder. A few definitions of terms will be helpful at this point to more fully understand the use intended herein. A negative pressure source" refers to a cylinder or other means which is partially evacuated of gases to lower its internal pressure below atmospheric pressure. Similarly a positive pressure source refers to a cylinder or other means containing a compressed gas to create an internal pressure greater than atmospheric pressure. The term vacuum" refers to a negative pressure but not necessarily to an absolute void. The term fluid encompasses both gases and liquids The gases referred to are those commonly found in the atmosphere and identified generally as air.

The imaging suspension holding tank 54 maintains a quantity of imaging suspension 56 in its hermetically sealed chamber. Gases from the positive pressure gas source 58 enter the tank 54 through a gas regulator 59 which sets the positive pressure in the suspension hold ing tank 54. The mechanism 60 maintains the seals in the closure of the tank to prevent fluids escaping therefrom.

To reach the extruder 4, the suspension must pass through a valve 62 operated by a cylinder 64 and a crank arm linkage combination 66. The valve has a passage way 68 therein which, when turned in the proper direction, permits a pulsed shot of suspension to pass through the conduit 70 to the distribution manifold 72 for passage through the individual ink flow metering valves 73-76. The valve 62 is opened and closed by the action of the solenoid SOL-ll and the 4-way valve 78 having a gas intake conduit 79 and an exhaust conduit 80. The solenoid and 4-way valve operate to move the piston 82 of the cylinder 64 to rotate the valve 62 thus opening and closing the passageway. This connects the suspension 56 from the tank 54 to the conduit 70 allowing for pulsed shots of suspension through the distribution manifold 72 and conduits 77a-80a to the extruder 4.

An alternative embodiment for an extruder mechanism is shown in FIG. 4i. An extruder housing 84 with a suspension intake connection 86 has an internal chamber 87 for accumulating suspension. The suspension is forced through the extruder at the exit aperture 88 for application to the surface 2 of the injecting electrode I. To ensure that a smooth uniform layer of suspension moves to the imaging area, a smoothing rod 89 is placed downstream from the extruder along the path of movement of the surface. The smoothing rod is journaled through the support bracket 90 of a shaft 91 to freely rotate while being driven by the injecting electrode ll.

While this invention has been described with refer ence to the structures disclosed herein and while certain theories have been expressed, it is not confined to the details set forth; and this application is intended to cover such modifications or changes as may come within the purposes of the improvements and scope of the following claims.

What is claimed is:

1. A coating apparatus comprising:

a. a carriage;

b. a housing pivotally connected to said carriage;

c. an applicator mounted in said housing and adapted to be brought into contact with a surface to be coated;

d. a chamber defined by a portion of said housing, said chamber for maintaining a reservoir of coating material to be applied by said applicator;

e. pressure adjusting means to vary the contact pressure of said applicator against the surface to be coated by varying the pivot of said housing and said applicator relative to said carriage, wherein said pressure adjusting means is operatively connected between said carriage and said housing; and

f. drive means for advancing said carriage, said housing and said applicator into and out of contact with the surface to be coated.

2. Coating apparatus according to claim 1 wherein said applicator is a roller mounted for rotation in said housing and including in combination a. a second chamber defined by a portion of said housing, said chamber for collecting coating material from the surface of said applicator roller after said roller has contacted the surface to be coated; and

b. removing means for removing uncoated material from said applicator roller portions after said portions have contacted the surface to be coated and to remove such material to said second chamber prior to the portions rotating into the chamber for maintaining a reservoir of coating material to be applied by said applicator.

3. The coating apparatus according to claim 2 wherein said removing means comprises a scraper blade which also separates said chamber and said second chamber.

4. Coating apparatus according to claim 3 wherein said second chamber is a vacuum chamber and further including in combination coating material removal means for removing coating material from said second chamber which has been scraped from said roller applicator.

5. Coating apparatus according to claim 3 including in combination supply means for supplying coating material under pressure to said chamber.

6. Coating apparatus according to claim 5 including in combination means for supplying metered amounts of coating material to said chamber comprising a pulsing valve means to enable pulsed shots of coating material to pass to said chamber.

7. Coating apparatus according to claim 3 further including in combination a smoothing means connected to said housing to form a uniform layer of coating material on the surface of said applicator roller after it has come in contact with coating material from said chamber but before it contacts the surface to be coated.

8. An extruder apparatus for applying coating material to a surface comprising:

a. a carriage;

b. an extruder housing mounted to said carriage, said housing defining an exit aperture;

c. a chamber defined internally by said housing, said chamber for maintaining a reservoir of coating material to be applied through the exit aperture;

d. supply means for supplying coating material to said chamber;

e. valve control means to enable pulsed shots of coating material to be supplied to said chamber and then through the exit aperture to a surface to be coated;

f. a smoothing rod mounted on said extruder housing downstream from said exit aperture along the path of movement of the surface to smooth the coating materials coated on the surface to be coated through the exit aperture; and

g. drive means for advancing said carriage, said extruder housing and said smoothing rod to and from the surface to be coated, so that said smoothing rod could be brought into and out of contact with said surface.

9. A coating apparatus comprising:

a. a carriage;

b. a housing pivotally connected to said carriage;

c.,an applicator roller mounted for rotation in said housing and adapted to be brought into contact with a surface to be coated;

d. a chamber defined by a portion of said housing, said chamber for maintaining a reservoir of coating material to be applied by said applicator roller;

e. a second chamber defined by a portion of said housing, said chamber for collecting coating material from the surface of said applicator roller after said roller has contacted the surface to be coated;

f. removing means for removing uncoated material from said applicator roller portions after said portions have contacted the surface to be coated and to remove such material to said second chamber prior to the portions rotating into the chamber for maintaining a reservoir of coating material to be applied by said applicator, said removing means comprising a scraper blade which also separates said chamber and said second chamber;

g. pressure adjusting means to vary the contact pressure of said applicator roller against the surface to be coated by varying the pivot of said housing and said applicator roller relative to said carriage;

h. supply means for supplying coating material under pressure to said chamber, said supply means including means for supplying metered amounts of coating material to said chamber comprising a pulsing valve means to enable pulsed shots of coating material to pass to said chamber; and

i. drive means for advancing said carriage, said housing and said applicator roller into and out of contact with the surface to be coated, said drive means for advancing said carriage comprising:

i. a stationary brace slideably mounting said carriage,

ii. a rack mounted on said carriage,

iii. a rod,

iv. rod drive means for advancing said rod,

v. a pinion engaging said rack, and

vi. a crank arm connecting said rod and said pinion to translate the movement of said rod to said carriage.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 743 Dat d I April 2 1974 Inventor(s) R aymond K. Egnaczak It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 62, delete "intention" 2nd occ. and insert --inventi0n-.

Signed and sealed this 5th day of November 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Commissioner of Patents Attesting Officer USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTING OFFICE: I989 0*366-384,

F ORM PO-IOSO (10-69) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 0.743 Da April 2, 1974 Inventor(5) V Raymond K. Egnaczak It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 62, delete "intention" 2nd occ. and insert --invention--.

Signed and sealed this 5th day of November 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Arresting Officer Commissioner of Patents USCOMM- DC 6037 6-1 69 U.S. GOVERNMENT PRINTING OFFICE I969 0-366-334,

FORM PO-IOSO (10-69)

Claims

1. A coating apparatus comprising: a. a carriage; b. a housing pivotally connected to said carriage; c. an applicator mounted in said housing and adapted to be brought into contact with a surface to be coated; d. a chamber defined by a portion of said housing, said chamber for maintaining a reservoir of coating material to be applied by said applicator; e. pressure adjusting means to vary the contact pressure of said applicator against the surface to be coated by varying the pivot of said housing and said applicator relative to said carriage, wherein said pressure adjusting means is operatively connected between said carriage and said housing; and f. drivE means for advancing said carriage, said housing and said applicator into and out of contact with the surface to be coated.

2. Coating apparatus according to claim 1 wherein said applicator is a roller mounted for rotation in said housing and including in combination a. a second chamber defined by a portion of said housing, said chamber for collecting coating material from the surface of said applicator roller after said roller has contacted the surface to be coated; and b. removing means for removing uncoated material from said applicator roller portions after said portions have contacted the surface to be coated and to remove such material to said second chamber prior to the portions rotating into the chamber for maintaining a reservoir of coating material to be applied by said applicator.

8. An extruder apparatus for applying coating material to a surface comprising: a. a carriage; b. an extruder housing mounted to said carriage, said housing defining an exit aperture; c. a chamber defined internally by said housing, said chamber for maintaining a reservoir of coating material to be applied through the exit aperture; d. supply means for supplying coating material to said chamber; e. valve control means to enable pulsed shots of coating material to be supplied to said chamber and then through the exit aperture to a surface to be coated; f. a smoothing rod mounted on said extruder housing downstream from said exit aperture along the path of movement of the surface to smooth the coating materials coated on the surface to be coated through the exit aperture; and g. drive means for advancing said carriage, said extruder housing and said smoothing rod to and from the surface to be coated, so that said smoothing rod could be brought into and out of contact with said surface.

9. A coating apparatus comprising: a. a carriage; b. a housing pivotally connected to said carriage; c. an applicator roller mounted for rotation in said housing and adapted to be brought into contact with a surface to be coated; d. a chamber defined by a portion of said housing, said chamber for maintaining a reservoir of coating material to be applied by said applicator roller; e. a second chamber defined by a portion of said housing, said chamber for collecting coating material from the surface of said applicator roller after said roller has contacted the surface to be coated; f. removing means for removing uncoated material from said applicator roller portions after said portions have contacted the surface to be coated and to remove such material to said second chamber prior to the portions rotating into the chamber for maintaining a reservoir of coating material to be applied by said applicator, said removing means comprising a scraper blade which also separates said chamber and said second Chamber; g. pressure adjusting means to vary the contact pressure of said applicator roller against the surface to be coated by varying the pivot of said housing and said applicator roller relative to said carriage; h. supply means for supplying coating material under pressure to said chamber, said supply means including means for supplying metered amounts of coating material to said chamber comprising a pulsing valve means to enable pulsed shots of coating material to pass to said chamber; and i. drive means for advancing said carriage, said housing and said applicator roller into and out of contact with the surface to be coated, said drive means for advancing said carriage comprising: i. a stationary brace slideably mounting said carriage, ii. a rack mounted on said carriage, iii. a rod, iv. rod drive means for advancing said rod, v. a pinion engaging said rack, and vi. a crank arm connecting said rod and said pinion to translate the movement of said rod to said carriage.