US2168968A

US2168968A - Web coating apparatus

Info

Publication number: US2168968A
Application number: US184456A
Authority: US
Inventors: David A Babcock; Henry E Van Derhoef
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1938-01-11
Filing date: 1938-01-11
Publication date: 1939-08-08
Anticipated expiration: 1956-08-08

Description

Aug. 8, 1939. D. A. BABcocK ET A1.

WEB COATING APPARATUS Filed Jan. ll. 1938 9 :0J 40. IIII Il lTmmlLl |IIIIIIPI rlllllflllLLlll wwe/.4. Mmc/e Hen/:y f. Vaner/loef BY @am A TTOR'EYS Patented Aug. 8, 1939 PATENT OFFICE WEB CGATING APPARATUS David A. Babcock and- Rochester, N. Y., Company, Rochester, New Jersey Application January 11,

7 Claims.

The present invention relates to coating apparatus, and more particularly to means for permitting the application of a fresh coating to one side of a web of material, the other side of which has already been coated with a similar or different solution which is still wet.

In the production of sheet material of many forms, such as plastic sheeting, paper, web materials, adhesive tape, artificial leather, photographic nlm, photographic paper, by way of example, it is often found necessary or desirable to treat the surface of the sheet with a liquid agent, in order to leave a deposit on the sheet by evaporation, setting or congealing of the liquid, or simply to alter the character of the surface by the action of solvents or chemical agents. Several means or methods are available for applying the liquid for as long a time as feasible, after which a continued or continuous motion brings the sheet out of contact with the liquid. The particular method of application to which this invention refers, is that in which the moving sheet or lm passes around the surface of a roll the periphery of which may or may not move at the same rate of speed as the film, and while in contact with the roll dips to a greater or less extent below the surface of the liquid coating material, which is contained in a suitable vessel.

In known apparatus for carrying out this process, which may be called the immersion process in coating, the surface of the sheet not being coated is in contact with the whole or part of the immersion roller during immersion, safe edge cups being provided at the ends of the immersion roller to prevent the coating solution from coming in contact with the reverse side of the sheet or film, or with the surface of the immersion roller. While this method of coating is satisfactory where only one side of a sheet or lm is to be coated, it is not satisfactory where it is desired to apply a coating to one side of a sheet at one coating station, and subsequently another coating to the other side of the sheet at another coating station, particularly when one coating is to be applied while the other coating is still wet.

Therefore, one object of the present invention is to provide a coating apparatus with an immersion roller which supports the sheet to be coated at its edges only thereby allowing the coating of one side of the sheet While the other, which has previously been coated, is still wet. Another object is to provide a coating apparatus wherein the immersion roller is protected by safe edge cups so that only one side of the immersed sheet is coated at a time, allowing the individual application of Henry E. Van Derhoef,

assignors to Eastman Kodak N. Y., a corporation of 1.938, Serial No. 184,456 (Cl. 91-46) different coatings on either side of the sheet. A further object is to provide an apparatus of the type referred to wherein the safe edge cups are mounted in such a way as to insure their proper cooperation with the immersion roller at all times. And still a further object is to provide an apparatus of the type referred to wherein the immersion roller and the safe edge cups are simultaneously adjusted through the actuation of a single means so as to accommodate webs of material to be coated which are of different widths. And a further object is the provision of an apparatus of the type referred'to which is simple in construction, and simple and efficient in operation.

Briefly, the present invention consists of an immersion roller comprising two spools for supvporting the web to be coated at its edges only, said spools being adjustable relative to one another for accommodating ebs of different widths. Associated with each spool is a safe edge cup which encases the end of the spool and engages the web passing thereover to prevent the coating solution from wetting the reverse side of theweb or wetting the supporting spool. 'I'hese safe edge cups are so mounted relative to the spool that the pooperation between the two is automatically controlled by a combination of forces induced by gravity and resilient means. The safe edge cups are adjustably mounted relative to one another and are connected to theV adjusting means for the spools so that the safe edge cups and spools are simultaneously adjusted by a single adjusting means.

The novel features that we consider characteristic of our invention are set forth with particularity in the appended claims. 'Ihe invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specie embodiments when read in connection with the accompanying drawing in which;

- Fig. 1 is a broken front view of a preferred form of the combination, partly in elevation and partly in section, and clearly showing the combination in coating position,

Fig. 2 is an end elevation of Fig. 1, showing the relation of the supporting means for the immersing roller and the safe edge cups, and the means for adjusting the two simultaneously to accommodate webs of different widths,

Fig. 3 is a detail showing the method of mounting the safe edge cups, and

Fig. 4 is an enlarged detail clearly showing the cooperation between one safe edge cup and one end of the immersion roller.

Like reference characters refer to correspond ing parts throughout the drawing.

Referring now to the drawing, reference 5 designates two spaced frame members which may be part of a machine including one or a plurality of coating stations of the type shown in the drawing and described fully hereinafter. Extending across the frame members 5 and being journaled at either end in bearings 6 therein is a shaft 1 having two threaded

portions

8 and 9, one being left-hand threaded while the other is right-hand threaded for the purpose hereinafter described. In threaded engagement with the threaded

portions

8 and 9 and extending vertically below the shaft 1 are brackets III the lower ends of which constitute bearings II in which the edge spools I2 are rotatably mounted. In the forms shown, these edge spools include a comparatively short cylindrical portion I3, a flange Il, and a tapered portion I5, clearly shown in Fig. 4. The web of material W which is to be coated is fed from the source of supply or from a previous coating station where it has been coated on one side, in the direction indicated by the arrows in Fig. 3 and is passed over the edge spools I2. The web W is supported at its edges only on the cylindrical portion I3 of the spool, the flanges Il serving merely to guide the web and prevent it from running olf of the spool. When a wide web of material issupported in a loop by supporting it at its edges only, the tube or loop formed, if of proper diameter, lends sufficient rigidity to the unsupported expanse of the web so that it will withstand a slight pressure tending to collapse the unsupported section. Therefore, the diameter of the cylindrical supporting portion I3 of the edge spools I2 is determined by the thickness, stiffness, and width of the web of material to be coated so that the unsupported portion of the web will have suilicient rigidity to overcome the tendency to collapse when brought into contact with the coating solution. By way of example, it has been found that an edge spool having a cylindrical portion 21/4 inches in diameter will support a film support .005 inch thick and 54 inches wide.

The tapered portion I5 of each of the edge spools I2 is bored out to receive the ends of tubes I3 and I5', and each of these tubes is pinned to its respective spool and telescope with one another to allow the spools to be adjusted toward and away from one another to accommodate webs of different widths. A pin and slot connection, indicated at I1, is provided between the telescoping tubes I6 and I6 to allow them to be adjusted axially but to insure both spools rotating at the same speed. These telescoping tubes I6 and I6' constitute a spindle connecting the two edge spools I2, and the combination of said spindle and said edge spools constitute the novel form of immersion roller on which the web is supported on its edges while being immersed in the coating solution. The diameter of the telescoping tubes I8 and I5' is less than that of the cylindrical supporting portion I3 of the edge spools I2, and this fact along with the fact that the inner end of the edge spool tapers inwardly, as shown at I5, insures that the surface of the web not being coated does not contact any portion of the immersion roller save at its edges. If the unsupported portion of the web W should for any reason tend to momentarily collapse, it will contact the tapered portion I5 of the edge spool I2 or the spindle formed by the telescoping tubes I6 and I5',

and will thereby be prevented from complete collapse wherein its edges would become disengaged from the supporting surfaces I3 necessitating a shut down of the machine. While the safe edge spools I2 have been shown including tapered 5 portions I5 and as being connected by a spindle, it is pointed out that these safe edge spools I2 could be formed without the tapered portions I5 and could be mounted to rotate independently of one another without the benefit of the described connecting spindle and without going beyond the scope of the present invention.

In order that the coating solution will not pass around the end of the edge spools I2 to wet the reverse side of the web supported thereby, or wet the edge supporting spool itself, the following structure is provided. Extending across the frame members and being journaled in bearings IB therein is another shaft 20 which includes right and left hand threaded portions 2| and 22.

'Ihis shaft 20 is parallel to and identical with shaft 1 supporting the edge spools and is located behind and slightly above shaft 1, see Figs. 1 and 2, the web W passing between the two shafts on its way to the immersion roller. In threaded engagement with the threaded portions 2| and 22 on the shaft 20 are brackets 23 having

arms

24 and 25, see Fig. 3. A hanger 25 is suspended from each of the brackets 23 by means of a pair of fiat springs 21 and 2B connected to the

arms

24 and 25 of the brackets 23. An offset arm 29 is pivotally supported in each hanger 25 by means of a pin 30 thereon engaging an inclined slot 3l in the hanger 25, see Fig. 3. Integral with one end of each arm 29 is a safe edge cup 32 which encases the end of each edge spool I2, and on the other end of the arm is a counterweight 33 which is heavier than the safe edge cup 32 and tends to force the same vertically upward in the direction of the force Fx.

Referring particularly to Figs. 1, 3 and 4, it will be noticed that each safe edge cup 32 is semicircular in shape and is deep enough to receive and encase the lower portion of its respective edge spool I2 and the bearing I0 therefor. One end 4:

wall 34 of the safe edge cup 32 is straight across the top and completely covers the lower portion of the edge spool, but the other vertical wall or dam 35 is arcuate to conform to the shape and size of the loop of the web supported on the edge 51 spools I2. Under the action of the counter weight 33 the safe edge cup 32 is forced upward so that the dam 35 will engage the surface of the web, and the effect of the counter weight is carefully controlled on the web W will provide a liquid tight joint at this point to prevent the passage of the coating solution into the safe edge cups. Although the dam 35 is shown as engaging the web W adjacent the supporting surface giving an indication that the liquid tight joint might depend upon the depression of the web adjacent said supporting surface I3 of the spool, it is pointed out that the dam 35 could be located so as to press the web directly against the supporting surface I3 `and still give the required liquid tight joint at this point. While the dam 35 could be formed as an integral part of the safe edge cup I2, we have chosen to show it as a separate member removably attached to the bottom of the safe edge cup I2 by a holding strip 31 and screws 33 so that it can be easily interchanged for a new one in the event it becomes inefficient due to wear or damage, see Fig. 4. The

flat springs

21 and 23 supporting the cup assembly f so that the pressure of the dam 35 5 I3 of the edge spool I2, e

A means of handle tained which exerts a slight pressure at the point on the dam where the web leaves the cup. 'I'his force FI tends to make the safe edge cup I2 flt 'tightly around the loop of the web as the web leaving the spool pulls it up.

A tank 40 containing the coating material L is adjustably mounted relative to the immersion roller so that it can be brought up to the roller for immersing the web thereon, or canbe removed therefrom to permit the web W to be threaded over the immersion roller. For the purpose of illustration, we have shown a pair of screws 4I rotatably mounted on the frame 5 in threaded engagement with which are a pair of supporting brackets 42 which carry the tank 40. The shaft 43 rotatably mounted in the frame members 5 has a pair of beveled gears 44 aiiixed thereto in engagement with bevel gears 45 on the ends of the screws 4I, and by rotating the shaft 43 by 46 the screws 4I will be rotated simultaneously to raise or lower the tank depending upon the direction in which the handle 46 is rotated. In immersing position, the top of the tank 40 is substantially below the open end of the safe edge cup 32 so that any overflow which might occur in the tank will not enter the safe edge cup. The safe edge cups 32 are designed so that the bottom 41 thereof is well below the bottom of the safe edge spool so that in case there may be a slight momentary accidental leak of the coating solution through the joint formed between the web and the dam 35, it can be accumulated in the bottom of the safe edge cup without coming in contact with the supporting surfaces I3 of the edge spools I2 or without passing to the other side of the web W. The solution leaking through the dam 35 may be removed from the safe edge cup 32 by suction nozzles (not shown) before the level has reached a point to cause wetting of the edge spool I2 or the back l of the web W. l

So that the immersion roller and its associated safe edge cup 32 can be adjusted relative to one another for accommodating webs of different widths, the shaft 1, on which the edge spools I2 are mounted, is directly geared to a shaft 2D, on which the safe edge cups are mounted, through engaging spur gears 48 and 49 xed to said shafts.

By virtue of this gearing connection and the threaded connections between the spools and safe edge-cups with said shafts, when handle 50 is rotated, both shafts are simultaneously rotated whereupon each edge spool and its respective safe edge cup is moved to or from the other edge spool and its safe edge cup depending upon the direction of rotation ofthe handle. The pitch of the threaded

portions

8 and 9 on shaft 'I and 2| and 22 of shaft 20 should be the same, as should the size of the spur gears 48 and 49 so that upon rotation of the handle 50 both shafts will be rotated at the same speed and the edge spools I2 and their respective safe edge cups 32 will be moved simultaneously at the same rate so that their positions relative to one another will be maintained.

While we have shown one coating station of a web feeding machine, it will be obvious to one skilled in the art that a single machine may contain one or a plurality of such coating stations through which the web can be properly fed in order to receive one or more coatings of the same or different solutions on either or both surfaces thereof. In a machine using an immersion roller of the type described the web will necessarily be supported on all subsequent immersing and drying rollers at the edges only, and since the structure shown insures a dry and uncoated selvage along each edge of the web, the necessary frictional engagement between the web and subsequent rollers, particularly the driving rollers for feeding the web, will be insured. After the web has been compietely treated, the uncoated selvage is cut off leaving a web uniformly treated on ,each surface with any different number and kinds of coating material desired. With the coating apparatus described, one surface of a web may be coated While the other surface thereof, which has been previously coated is still wet; and a great saving of time and space is manifested. In addition, since the immersion roller can be easily adjusted for accommodating webs of different widths, it has the versatility of several machines which would accommodate only one width web.

Although we have shown and described certain specic embodiments of our invention, we are ful/ly aware that many modifications thereof are possible. Our invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and the spirit of the appended claims.

Having thus described our invention, what we claim is new and desire to secure by Letters Patent is:

1. In a web coating apparatus, the combination with an immersion roller for a web of material to be coated, said roller` comprising a pair of spaced circular supporting surfaces for supporting the web of material at its edges only,v a spindle connecting said supporting surfaces and being of smaller diameter than said supporting surfaces whereby that portion of the web between the supporting surface is free from contact with the roller, of means for encasing the endsv of said roller and engaging the surface of the web adjacent said supporting surfaces to form a liquid tight joint between the center of the roller and its ends, and a tank containing the coating liquid, said tank confining the lower portion of the immersion roller whereby the unprotected portion of the web of material on the roller will be immersed in the coating solution.

2. In a web coating machine, the combination with an immersion roller for a web of material to be coated, said roller comprising a. pair of spaced circular supporting surfaces of one diameter for supporting the web at its edges only, a spindle connecting said supporting surfaces whereby that portion of the web between the supported edges is free from contact with the roller, of a tank containing the coating solution and located adjacent the immersion roller so that the web on the roller is immersed in said coating solution, and means adjustably mounted relative to said roller for encasing the ends of said roller and pressing the web of material toward the roller to form liquid tight joints between the center of the web and the ends thereof.

3. In a web coating apparatus, the combination with a tank containing a coating solution, an immersion roller for a web of material to be coated, said roller comprising a pair of spaced circular supporting surfaces extending below the surface of the liquid in the tank and for supporting the web at its edges only, a spindle connecting said spaced supporting surfaces and being of smaller diameter `than said supporting surfaces whereby that portion of the web between the supporting surfaces does not contact the roller, and means for encasing the ends of the immersion roller and pressing the web toward the roller throughout its arc of contact therewith to form a liquid tight joint between the supported edges and the center of the web.

4. In a web coating apparatus, the combination with means for supporting a web of material to be coated, said means including a pair of spaced circular supporting surfaces for supporting the web of material at its edges only, means for adjustably mounting said supporting surfaces whereby they can be moved relative to one another to accommodate webs of dlierent widths, of a pair of safe edge cups for encasing the ends of the supporting surfaces and engaging the surface of the web adjacent said supporting surfaces to form a liquid tight joint between the supported edges of the web and the center thereof, adjustable supporting means for said safe edge cups whereby they can be adjusted along with the supporting surfaces, and a tank containing the coating solutions, said tank adjustably mounted relative to the immersion roller for bringing the coating material into contact with the unprotected portion of the web on the immersion roller.

5. In a web coating apparatus the combination with an immersion roller for a web of material to be coated, said roller comprising a pair of spaced circular supporting surfaces for supporting the web at its edges only, an adjustable spindle connecting said supporting surfaces, the diameter of said spindle being less than the diameter of said supporting surface whereby that portion of the web between the supported edges is free from contact with the roller, means for adjusting said supporting surfaces relative to one another to accommodate webs of different widths, of safe edge cups encasing the ends and lower portion of the supporting surfaces and engaging the surface of the web adjacent said supporting surfaces to form a liquid tight joint between the center of the roller and its edges, means for adjusting the safe edge cups relative to one another, said means connected to the adjusting means for the supporting surfaces whereby the supporting surfaces and the safe edge cups are adjusted simultaneously, and a tank containing the coating solution, said tank adjustably mounted for bringing the coating solution into contact with the unprotected portion of the web on the immersion roller.

6. In a web coating apparatus, the combination with an immersion roller for a web of material to be coated, saldroller comprising a pair of spaced narrow spools for supporting the web at its edges only, an adjustable spindle connecting said spools, the diameter of said spindle being less than the diameter of the spools whereby that portion of the web between the spools is free from Contact with the roller, means for adjusting the spools relative to one another to accommodate different width webs, of a safe edge cup encasing the ends and lower portion of each of said spools, an arcuate lip on each of said safe edge cups arranged to engage the surface of the web adjacent the spools to form a liquid tight joint between the edges and center of the immersion roller, means for normally forcing each safe edge cup toward its respective spool to press the lip against the web, means for adjusting said safe edge cups relative to one another and connected to the adjusting means for the spools whereby cach spool and its safe edge cup are moved together, and a tank containing the coating solution, said tank adjustably mounted for bringing the coating solution into contact with the unprotected portion of the web on the immersion roller.

7. In a web coating apparatus, the combination wth an immersion roller for a web of material to be coated, said roller comprising a pair of spaced narrow spools for supporting the web at its edges only, an adjustable spindle connecting said spools, the diameter of said spindlebeing less than the diameter of the spools whereby that portion of the web between the spools is free from contact with the roller, means for adjusting the spools relative to one another to accommodate diiferent width webs, of a safe edge cup encasing the end and lower portion of each of said spools, an arcuate dam on each of said safe edge cups arranged to engage the surface of the web adjacent the spools to form a liquid tight joint between the edges and center of the immersion roller, combined resilient and gravity actuated means for normally forcing each safe edge cup toward its respective spool to control the pressure of the dam against the web, means for adjusting said safe edge cups relative to one another and connected to the adjusting means for the spools whereby each spool and its safe edge cup are moved together, and a tank containing the coating solution into contact with the unprotected portion of the web on the immersion roller.

DAVID A. BABCOCK. HENRY E. VAN DERHOEF.