US3884180A

US3884180A - Coating apparatus

Info

Publication number: US3884180A
Application number: US297669A
Authority: US
Inventors: Ford H Mcberty
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-16
Filing date: 1972-10-16
Publication date: 1975-05-20
Anticipated expiration: 1992-05-20

Abstract

A means for coating a material on both sides of a tape is made available which affords a turbulence chamber, for example, by means of an element that has an orifice that approximates the thickness of the tape and has serrations and in proximity to it a second orifice that also approximates the thickness of the tape but has larger serrations than those in the first orifice. The tape can be roll fed into a shallow pool of the coating material and then into the turbulence chamber through the orifice having the larger serrations. More coating material than is needed is carried by the tape but the exotropic nature of the coating material is broken down, so that when the tape passes through the orifice having the smaller serrations, a smooth thin coating results. Serrated orifices are not necessary in certain embodiments as discussed below. The side walls between the two orifices can be shaped to form a tapered chamber to control the direction of the tape. The coating die just described is mountable on a vessel that can contain the coating material, and the orifice having the larger serrations is at the tapered end of the chamber and is just above the coating material. The finely serrated orifice is, thus, the outermost one with reference to the coating material. In one embodiment, the uncoated tape is preferably pushed into the first orifice and through it downwardly. As it so passes, it is guided by the tapered chamber into and through the second orifice and hence into the container. Coating is effected by immersing the tape within the container in the liquid material and then withdrawing it by pulling on the free end that has been left outside the container above the first orifice. The second orifice with its larger serrations affords a rough spreading of the coating material on both sides of the tape. As the tape passes through the tapered chamber and through the finer serrated orifice and out of the device, the coatings on the tape are reduced in thickness and are converted into uniform coatings all over the two sides of the tape. The free end which is used to withdraw the tape never has to contact coating material affording a ready handling of the coated product. In another embodiment, the tape is fed from a roll outside the container through a slot in the container to and through a roll system upwardly to and through the die of this invention. Coating material, which is already in the container or is added after the threading-up step preferably through a supply tied in with the container, is present as a shallow pool and is carried by the upwardly moving tape or is brushed, squeezed, sprayed or the like against the tape in the turbulence chamber.

Description

United States Patent McBerty May 20, 1975 COATING APPARATUS ken down, so that when the tape passes through the [76] Inventor, Ford McBerty, RD 3 BOX 243, orifice having the smaller serrations, a smooth thin Oxford Pa. 19363 coatmg results. Serrated or1f1ces are not necessary in certain embodiments as discussed below. [22] Filed: 1972 The side walls between the two orifices can be shaped [21] Appl. No.: 297,669 to form a tapered chamber to control the direction of the tape. The coating die just described is mountable on a vessel that can contain the coating material. and ll8/l2651cl$1/l (1)g the Orifice having the larger mutations is at the Field of 125 122 tapered end of the chamber and 15 ust above the llg/bfdnig 43/114417 1177 coating mater1al. The finely serrated onfice 15, thus. 22/181 164 the outermost one w1th reference to the coatmg material. In one embodiment, the uncoated tape is preferably pushed into the first orifice and through it [56] References cued downwardly. As it so passes, it is guided by the UNITED STATES PATENTS tapered chamber into and through the second orifice 1,269,604 6/1918 Heuer l18/DIG. 19 and hence into the container. Coating is effected by 1,734,474 11/1929 Creech 222/185 immersing the tape within the container in the liquid Girard 6t al. l X matgrial and then on the free 1,803,951 5/1931 ThQma 118/121 end that has been left outside the container above the et g 3 first orifice. The second orifice with its larger 2:165:03 7/1939 i: X serrat ons affords a rough spreadlng of the coatmg 2193.887 3/1940 seeley U 118/405 X materlal on both s1des of the tape. As the tape passes 2,366,077 12/1944 Wildy etal. 118/125 through the tapered Chamber and through the finer 2 429 370 10/1947 Dahistmm 118/1310, 13 serrated orifice and out of the device, the coatings on 2,868,159 1/1959 Lit et a1. 118/125 the tape are reduced in thickness and are converted Primary Examiner-Morris Kaplan [5 7] ABSTRACT A means for coating a material on both sides of a tape is made available which affords a turbulence chamber, for example, by means of an element that has an orifice that approximates the thickness of the tape and has serrations and in proximity to it a second orifice that also approximates the thickness of the tape but has larger serrations than those in the first orifice. The tape can be roll fed into a shallow pool of the coating material and then into the turbulence chamber through the orifice having the larger serrations. More coating material than is needed is carried by the tape but the exotropic nature of the coating material is brointo uniform coatings all over the two sides of the tape. The free end which is used to withdraw the tape never has to contact coating material affording a ready handling of the coated product.

In another embodiment, the tape is fed from a roll outside the container through a slot in the container to and through a roll system upwardly to and through the die of this invention. Coating material, which is already in the container or is added after the threading-up step preferably through a supply tied in with the container, is present as a shallow pool and is carried by the upwardly moving tape or is brushed, squeezed, sprayed or the like against the tape in the turbulence chamber.

5 Claims, 10 Drawing Figures PATENTED HAYZ 0 I975 SHEET 10F 2 PAIENTED HAYZOIQYS 7 884, 18 O SHEET 2 OF 2 COATING APPARATUS BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION This invention relates to a coating device for spreading a layer of liquid material on each side of a film or tape. More particularly, this invention relates to a means for inserting a thin strip of material into a vessel which contains a liquid material to be coated onto the thin strip, which means affords the withdrawal of the thin strip uniformly coated with the said material This invention also affords a means for repeatedly coating the same thin strip.

There have been numerous devices for coating materials onto a substrate and many of these devices have been used for coating articles with materials to form an article useful in killing various insects such as flies. However, heretofore, there has been available no equipment which allows the ready coating of thin, flexible strips. Practically all of the devices have been throw-away devices which are used the one time and then discarded. The use of such throw-away articles has a number of drawbacks. For example, in the mainte' nance of a large dairy farm, where flies are usually very numerous, ceilings in barns and the like are generally quite high and difficult to get to and it is in such areas that the insects tend to settle. Repeated replacements of devices that afford only exposures of small areas for a one-time use makes fly control in such commercial enterprises as dairy farms very difficult. Thus, an objective of this invention is to afford a container that is capable of holding a very substantial amount of coating material and that has a coating die that not only acts as a closure for the container but is a means for coating the thin strip of material in such a way that the coating material is applied to both sides of the strip in a uniform fashion. The thin strip that is used can be of any desired width depending upon the diameter of the opening to the container, and, hence, the diameter of the coating die. Very long lengths of the thin strip can be used. The coating equipment of this invention affords the insertion and removal of only a single thickness of the strip and the ready production of the desired layers of the coated material. Further, in the one embodiment the coating die of this invention was within it a guide that forces the thin strip directly downward onto or into the liquid in the container, preventing wandering of the film or tape. Also, the die or the coating means of this invention has an outermost inlet which is serrated, this inlet being at one end of the guide and at the other end of the guide is another serrated aperture. These serrations differ in size and number, and they cooperate to effect a uniform coating of the material on both sides of the film.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will be further understood by reference to the drawings and description below, all of which is given for illustrative purposes only and is not limitative.

FIG. 1 is a perspective of the one embodiment apparatus of this invention shown in the upright position and showing the withdrawal of a tape as it is being coated and hung in place with the hanger of this invention.

FIG. 2 is a plan view of FIG. 1 showing the tape about to come out of the uppermost or said first orifice of the coating die of this invention and showing the hanger lying horizontally on top of the device.

FIG. 3 is partly in cross-section and is taken on line 33 of FIG. 2.

FIG. 4 is a perspective of the coating die of this invention, showing the two halves in juxta-position.

FIG. 5 shows the coating die of this invention with a means for supporting it on the container of this invention.

FIG. 6 is a plan view showing the coating die of this invention from the bottom with means for holding the parts of the coating die together along with means for supporting it on the container.

FIG. 7 shows one embodiment of this invention in an inverted position, the container and coating die elements being in cross-section.

FIG. 8 is a cross-sectional view showing a die having the turbulence chamber outside and in conduit relationship with the container.

FIG. 9 is a perspective of apparatus of this invention embodying a continuous roll feed system; and

FIG. 10 shows in perspective supply and feeding means tied in with the container.

DESCRIPTION OF THE DRAWINGS AND EMBODIMENTS As can be seen in FIG. 1, a film 10 is partially immersed in liquid 11 contained in vessel 12. For convenience, vessel 12 is mounted on stand 13 which comprises legs 14, cross bars 14a (FIG. 2) and adjustable container supports 15. The film 10 extends above the top level of liquid 11 passing through the closure 16 and being attached at its outermost end to holder 17. Also as shown in FIG. 1, with the support 13 resting on the floor or a table top or some similar surface 18, the film can be pulled out of the container and mounted to a pin or hook 19 in ceiling or wall 20. This withdrawal is shown in phantom in FIG. 1 and the coating material is shown in the uppermost portion of tape 10 in a striated form 11a, for convenience. Preferably, the degree of viscosity or thixotropicity of the coating material is such that thinning or dripping is avoided, making the striations relatively permanent. However, if desired, in the use of thickners, both as to quantity and quality thereof, adjustments can be made so that the striations that are formed as the film is drawn through the die within closure 16 disappear due to the flowing of the striated material to form a uniform coating on both sides of the film. The striations shown in FIG. 1 are given merely to illustrate the type of coating that occurs immediately at the uppermost orifice of the coating die 21 (FIG. 3). With certain very viscous materials, the striations persist for some time without any substantial detriment to the insect removal desired, and such striations are preferred.

The uppermost aperture 22 is shown in the plan view given in FIG. 2 looking down upon the device of this invention. The holder 17 at the uppermost end of tape 10 is shown lying flat upon the top of the apparatus prior to its being pulled to its mounting place. As can be seen in FIG. 2, the die 21 is made up of two

sections

23 and 24 which come together forming aperture 22 and serrations 25. The two

sections

23 and 24 are shown in FIG. 3 where the guide 26 can also be seen. This guide comprises a triangular-shaped element made up of two parts each of which might be considered to be one-half of an isosceles or equilateral triangle, the bases of which come together to form the serrated aperture 22, the altitude edges of which come together to form the serrated aperture 27 (FIG. 6). The two halves of the die contain a recess 28 about midway, as shown in FIG. 4. Mounted in this recess, as shown in FIG. 5, is support 29 which in turn is held in place on the upright support 13 much in the manner shown in FIG. 3. As can be seen there, the support 29 rests on the top edges of container 12. This is shown at 30, for example. Container 12 can be threaded at the top to receive the threaded lid 31 which, when threaded at the top to receive the threaded lid 31 which, when threaded on the threads of the container, clamps the support 29 tightly up against the upper edges of container 12. Prior to placing the die 21 into locked position at the top of the container 12, the two sections are brought and held together by means of spring clip 32 at the underneath side, as shown in FIG. 6.

In order to hold the container 12 in position on support 13, a support 33 (FIG. 2) is provided that is threadily mounted or supported at the threaded ends of container 12 and its outer edges are clamped, screwed to or otherwise mounted on crossbars 140 as shown in FIGS. 2 and 3, screws 34 being shown. By the use of support 13 and auxiliary support 33, container 12 is kept off the floor. The upright legs 14 extend beyond the top of the coating device and beyond the bottom of container 12. Thus, the coating part of the apparatus of this invention is kept out of contact with the floor or ground whether upright or inverted. This prevents breakage and dirtying of the coating parts.

In using this embodiment, container 12 is partially filled with liquid 11 as shown in FIG. 3. Preferably, it should be filled only from about 50% to about 60% with the liquid coating material. Low levels can be used such as 25% and higher levels can also be used as, for example, up to about 75% fillings. However, in order to make the introduction of the uncoated tape into the container smoothly, amounts of more than 75% should be avoided, because the presence of too much material makes it difficult to introduce the tape into the liquid. The liquid mixtures used in this invention are nonpoisonous to live-stock and are generally very viscous compositions, and it is difficult to force a flexible film down into the liquid. Therefore, the apparatus in this embodiment is allowed to stand in the upright position for a convenient period of time in order to allow the liquid to drain downwardly into the vessel and to allow any liquid in the orifices of the die to drip away into the fluid below. When it is felt that all desirable drainage has occurred, the tape to be inserted, which may be a tape that has just been used and then cleaned, is inserted in either one of two ways. In one method, the screw cap or lid that holds the die element in position on top of the container is removed and one end of the new tape is pushed upwardly from the bottom of the die' so that about an inch or so projects from the uppermost orifice of the die. This allows for the attachment of hanger 17. Following this step, the bottommost section of the tape is then pushed into the liquid 11 and the cap is replaced with the die in position. This method is inconvenient and inefficient because it is a messy operation and the attachment of a hanger is fairly complicated. The preferred method is to take the end of the tape to be used that is free that is, the end which has no hanger attached to it and insert it through the uppermost orifice of the die, through the die and the guide mechanism and down onto or into the liquid, depending on its viscosity. The film or tape generally lies on top of the liquid as shown in solid lines in FIG. 3.

After attaching the hanger 17, if it is not already attached, the entire apparatus is inverted, as shown in FIG. 7. As can be seen there, film 10 now is completely immersed and covered by liquid 11. The inversion of the entire apparatus causes the fluid to flow down and around all of the tape and to cover or submerge the lowermost orifice 27 of the coating die. It is not necessary to see to it that all of the cavities within the guiding mechanism be filled with coating material, because the tape itself will carry coating material to the uppermost orifice as it is being removed after turning over the apparatus to place it in the upright position. In other words, once the fluid has reached the bottommost orifice of the die, the apparatus may be immediately inverted and the tape may be immediately withdrawn. With the inversion, the tape 10 takes a position much like that shown in dotted lines in FIG. 3.

In the withdrawal of the tape, coating material is carried with the tape to the bottommost edges 27 of the coating die. This bottommost edge has very wide serrations 35 (FIG. 6) and these serrations effect a fairly wide width of fluid material to be placed on both sides of the tape. The tape carrying the fluid with it from the bottommost wide serrations 27 in its upward pull passes through the uppermost orifice 22 where the serrations 25 are very small. In other words, the upper orifice may be considered to afford a fairly large plurality of doctor knife edges which come together in close proximity to allow a single thickness of the tape-to pass through it along with the liquid carried from below. As noted above, depending on viscosity, the liquid is caused to be thinned and to be spread out and the very small apertures between the doctor knife edges afford a minimum of sideway flow needed to get the uniform coating all over the tape on both sides, or relatively permanent striations can be produced. In either event, the small orifice at the top with its small serrations forces coating material downwardly toward the oncoming, relatively massive coating afforded by the large serrations below. The result is a turbulence that occurs on the tape within the chamber between the two orifices, the combination of which affords excellent coatings.

Generally, the speed of drawing the tape from the containers through the orifices is not critical, but it will vary from liquid to liquid depending upon the viscosity of the liquid. In general, the more viscous the liquid, the slower one will withdraw the tape in order to allow more time for the flow of the coating materials. The speed of the pull on the tape is generally short of risking tearing the tape. However, this is a factor which is very easily regulated by the user.

In another embodiment of this invention, the turbulence chamber, for convenience, is placed outside the vessel 12 as shown in FIGS. 8-10. The tape 10 can be handled in the manner described above, or, as shown in FIG. 9, a supply 36 can be contained on a roll held by bracket 37 mounted to a leg 14. Tape 10 is fed through a conventional gasketed orifice '38, if such is desired, in a wall of vessel 12 and then around roller 39 as shown in FIG. 9. Passing from roller 39 tape 10 goes directly to the die mechanism, through turbulence chamber 26 and out, bearing with it coatings 11a. The roller can be separately cantilever mounted to a wall of vessel 12 or it may be also conventionally mounted on a separate support, all of which is not shown for convenience. Irrespective of the mountings of the roller, once threaded no further threading is needed, for a new tape is readily mounted to the very end of tape coming off at supply 36, and the new roll simply replaces the old. The top or lid 16 is easily unscrewed to add more coating material, the flexibility of tape 10 affording its ready twisting without tearing or breaking it. If desired, the supply means 41 shown in FIG. 10 can be used.

In the embodiment shown in FIG. 10, a container 42 is present generally independently supported by vessel 12. It can be activated to supply coating material to vessel 12 through float 43 which activates valve 44 when the level of liquid 11 falls below a certain point. On such a happening, liquid flows from container 42 through valve 44 and conduit 45 into vessel 12.

In still another embodiment, pump 46 is present being in conduit relationship through pipe 46 with fluid in the bottom of vessel 12 and pumping it through pipe 47 into the turbulence chamber 26, as shown in FIG. 10. The coating material is thus applied to tape 10 in a relatively massive turbulent manner in the chamber 26. While this embodiment can avoid the need of both serrated orifices, the turbulence chamber is present, and, further, it is preferred to use finely serrated edges in the uppermost orifice 22. The applicator 48 in forcing liquid 11 against the tape 10 takes the place oflarge serrations 25 in effecting the turbulence desired within chamber 26.

As can be seen from the above, a narrow and coarsely serrated entrance slot is used in those instances in which the tape to be coated could approach the slot bunched up or in convolutions which approach could cause jamming, tearing or the passage of uncoated tape through the slot. Such a slot allows only a single thickness to pass and the coarse serrations afford the turbulence needed through ample entraihment of liquid. If the approach of the tape is such that one side might not get coated and there is no danger of bunching of the tape, the coarsely serrated slot will be wide, affording ample liquid and access of the coating fluid by ample flow to both sides of the tape before it reaches the outlet slot or die. If, however, the approach of the tape to the entrance slot assures contact of both sides of the tape with the liquid, then a wide, unserrated entrance slot can be used. In some instances, the space where the coating apparatus of this invention is to be used is very restricted, so that the flow ater removal of the tape through the outlet is curtailed. In such circum stances means within the turbulence chamber, such as described above, for making the liquid flow to both sides of the tape are provided. Here the slots used are narrow and unserrated so that maximum pressure within the turbulence chamber can be built up to effect more efficient flow of the coating material to both sides of the tape. These and other embodiments can be adjusted and provided for readily by the operator as dictated by the prevailing conditions he has.

In every embodiment of this invention there results a positive regulation of the coating to both sides of the tape so that uniform thicknesses of coating material are obtained. The apertures of the coating die are so adjusted to insure single thickness of the movement of the tape through the coating orifice. It is impossible for the tape to double up on itself and pass through the orifice in a doubledup fashion. There is very little resistance to the movement of the tape through the orifice and there is a minimum of obstruction of the flow of the coating material to the orifices of the coating die. Further, the coating die of this invention is constructed so that the insertion of the uncoated tape into the container is facilitated and can be effected so that the container does not have to be opened to insert another tape. Thus, the end of the tape that is to receive the hanger never has to come in Contact with the coating material and can be attached at any time. Most importantly, the turbulence chamber affords an efficient means of effecting uniform coatings of tape whether the coatings be in the form of uniform striations or in the form of unitary layers.

The apparatus of this invention also has the advantage that any length of tape can be used so that very great areas of various coating materials can be exposed to insect-infested areas with a substantial increase in the efficiency of the removal of such insects as flies. There are no hazards involved; the cost is very moderate; and the apparatus can be readily used with a minimum amount of preparation, maintenance and cleanup time involved.

While the invention has been disclosed herein in connection with certain embodiments and certain structural and procedural details, it is clear that changes, modifications or equivalents can be used by those skilled in the art; accordingly, such changes within the principles of the invention are intended to be included within the scope of the claims below.

I claim:

1. A device for use in coating a liquid material on a film or tape which device comprises a container for said liquid; disposed within the upper section of said container and above the level of any liquid therein a means for temporarily accumulating any liquid as it is being passed through said means, said means having a configuration and depth defined by at least two coacting plates spaced apart and forming two orifices in conduit relationship with each other, one orifice being an outlet from said device for said film or tape and liquid thereon and the other orifice being adapted to receive liquid and said film and tape first but having a slot width larger than that of said outlet orifice, the differential in said orifice sizes thereby effecting said accumulation and effecting turbulence of the accumulated liquid to thereby enhance said coating; and in combination with said device, an invertible support for said container affording inversion of said container.

2. A device in accordance with claim 1 in which each orifice is serrated, the serrations in said outlet orifice being smaller than those in said other orifice.

3. A device in accordance with claim 1 in which said co-acting plates diverge outwardly from the outlet end thereof.

4. In a container which can hold a liquid and a film or tape and including container support means adapted to further support said container in an inverted position, an element comprising a turbulence chamber disposed in the upper section of said container which chamber comprises at least two plates positioned apart from each other and each having an orifice therein and being in conduit relationship with each other, the one orifice being an outlet from said container for said tape or film and any liquid thereon and the other being adapted to receive said tape and liquid first but having a slot width larger than that in said outlet orifice, the differential in said orifice sizes affording temporary accumulation of said liquid in said chamber and affording application of said liquid in a turbulent manner to said tape or film.

5. An apparatus in accordance with claim 4 in which said orifices are serrated, the serrations in said outlet orifice being smaller than those in said other orifice.