US 3293063 A
Description (OCR text may contain errors)
H. E. POHL ETAL PROCESS AND APPARATUS FOR APPLYING LIQUID Dec. 20, 1966 IN A DISGONTINUOUS MANNER TO A SUBSTRATE Filed May 25, 1963 INVENTORS CLAYTON E. WORKMAN HAROLD E. POHL BY ATTORNEY United States Patent O PROCESS AND APPARATUS FUR APPLYING LIQUID IN A DISCBNTINUOUS MANNER T A SUBSTRATE Harold E. Pohl, Kankakee, IlL, and Clayton E. Workman, Minneapolis, Minn., assignors to General Mills, Inc, a corporation of Delaware Filed May 23, 1963, Ser. No. 282,757 17 Claims. (Cl. 11'745) This invention relates to a method and apparatus for applying in a discontinuous manner a liquid material to a base member to form thereon a desired decorative pattern, and more particularly to such a method and apparatus adapted to accomplish such a discontinuous application as one of the steps in a process disclosed in a copending US. patent application, Serial No. 193,846, filed May 10, 1962, now Patent No. 3,219,735, entitled Process for Producing a Decorative Coating and Products Produced by Said Process, of which the applicants herein are among the co-inventors.
With the process disclosed in this copending US. patent application, it is possible to produce a decorative coating which closely simulates polished surfaces of natural stone formations such as m arble, granite, etc., or surfaces of members which are made with natural stone, such as Terrazzo. The manner in which this is accomplished is that a base coat of a suitable resinous liquid material of a desired shade and color is applied uniformly over a surface of a substrate (i.e. a panel, such as a piece of plasterboard or beaver-board, pressed wood, fiber glass, metal etc.). After this base coating has polymerized or set for a predetermined length of time so that a break able or friable film has formed over the surface of the base coat, there is a subsequent application of a material similar to that which comprises the base coat but distinguishable therefrom in color and/or shade.
This second application of material is made in a discontinuous and random manner and with a moderate impact onto the base coat. It is believed that the effect of this is that various concentrations of material of this second application break through the film which has formed on the base coat and actually flow or spread outwardly to a moderate extent to form puddles, the peripheral portions of which extend beneath the base coat (i.e. between the base coat and the panel). After this discontinuous and random application of the second coat, the panel is either tilted or moved laterally to cause those portions of the base coat which overlap the peripheral portions of the second layer concentrations or puddles to break loose and slide over the second layer. The effect is to create a number of flakes of the base coat material which flakes are themselves spread in a somewhat random pattern over the various localized background areas formed by the concentrations of the material of the second discontinuous application. The panel is then allowed to stand so that the coatings can set up and harden.
When this process is used to make decorative panels for Walls, floors, and the like, to produce a proper esthetic effect and yet to realistically simulate panels made from natural stone, it is desirable to obtain some general uni formity or overall pattern for a particular group of panels, and yet to have each panel or portion thereof be distinctive within the limits of this general pattern. One reason for this is that natural stone is usually cut in successive layers or slabs, which, because of their proximity in the natural formation will be somewhat similar in overall pattern but will have individual variations. There is also the practical consideration that a user of these panels (e.g. a customer who is selecting a type of panel by sample) would desire the particular panels which he or she buys to be of a distinctive design and yet have the panels conform to some overall esthetic standard or pattern.
Thus it is an object to provide a method and apparatus to apply a liquid to a substrate member in a discontinuous and random manner, and yet in a manner which conforms generally to an overall pattern, so that While each application results in a truly distinctive design, there is conformity to a general esthetic standard or pattern.
It is also an object to provide such a method and apparatus which is especially adapted for use inthe aforementioned process described in said pending US. patent application (i.e. Serial No. 193,846), now Patent No. 3,219,735 which method and apparatus, while accomplishing the first named object, facilitate the practice of said above-mentioned process in creating a coating which realistically simulates a polished surface comprised of natural stone, and which conforms to a high esthetic standard.
It is yet another object to provide such a method and apparatus in which said random and discontinuous application of material can readily be accomplished with a multi colored liquid application, and in which the aims of both the afore-mentioned objects can be accomplished along with such multi-colored application.
It is a further object to provide a simple apparatus, which, while accomplishing the afore-mentioned objects, is capable of adjustment and/or rearrangement so that a great variety of truly distinctive patterns can easily be produced by this apparatus.
These and other objects and features of the invention will be more readily understood and appreciated from the following detailed description of the preferred embodiment thereof selected for purposes of illustration and shown in the accompanying drawing, in which:
FIGURE 1 is a perspective view of the applicator portion of an apparatus embodying preferred teachings of our invention, and
FIGURE 2 is a side elevational view, partly in section, of said apparatus.
In the accompanying drawing, numeral 11) designates generally a conveyor upon which a succession of panels 12 are carried along a predetermined course. As shown herein, this conveyor comprises an endless belt 14 having drive and idler rollers 16 and 18, respectively.
At the forward end of the belt 12 is a suitable means to apply to the upper surface of each of the panels 12 riding on the belt 14 a base coat of a suitable resinous liquid (as described in the afore-mentioned copending United States patent application). Such applicating means is shown schematically as a spray applicator 20 located above the belt 14. It is to be understood, however, that any suitable applicating means may be empioyed by which such a base coat is applied uniformly over a substrate member.
As the various panels 12 are carried by the belt 14 at a predetermined rate of travel rearwardly from the spray applicator 20, the freshly applied base coat begins to set" so as to form the afore-described friable film thereon. At the location along the conveyor 10 where each portion of the base coat applied to the panels 12 has set for the desired length of time, there is positioned an apparatus, generally designated 22, by which a second application of a suitable resinous liquid (as described in the aforementioned copending United States patent application) is made in a discontinuous manner onto the upper surface of the panel 12.
This apparatus 22 comprises a support frame 23, on which is mounted a plurality (three herein) of parallel and adjacent dispensing troughs 24a, b, and arranged to eifect a series flow of liquid of various shades and/ or colors onto a discharge apron 26, from which the liquid drops onto the panels 12 passing beneath. At the discharge edge 28 of the apron 26 is a damming spindle, which functions to intermittently block liquid flow over the apron 26 at various predetermined time intervals and at various predetermined locations along the apron 26.
Each of the troughs 24a, [9 and 0, comprising front, rear, bottom and side walls 32, 34, 36 and 38, respectively, is located moderately above, and extends transversely of, the conveyor belt 14, and is arranged to extend a slight distance beyond each of the side edges of the panels 12 passing therebeneath. There is provided for each trough 24a, b, and c a related pump 40a, b, and c, respectively, from which the afore-described liquid material of a particular shade and/or color is supplied to its related trough through a related feed pipe 42 at an accurately predetermined rate. The top edge 44a, 1), and c of the front wall 32 of each trough 24a, b, or c is moderately lower than the upper edge of its related rear and side walls 34 and 38, so that each front wall 32 acts as a weir over which the liquid from its related pump 46a, 12, or c flows at a predetermined rate. One of the troughs 24c is shown herein as being mounted (as at 43) to the frame 23 for swing motion about an axis parallel to its own length, and for limited vertical motion along with said swing motion to maintain the proper position relative to the trough 24b. Thus by slowly rotating trough 240 during the coating process, the flow therefrom may be varied, without need of changing the rate offlow from its related pump 400. The other troughs 24b and 24a may also be swing mounted either as a unit with trough 240 or individually.
Just below the top edge 44b and c of each of the middle and rear troughs 24b and c is a related one of two narrow moderately sloping drip aprons 45b and 0, respectively. The troughs 24a, 12, and c are so arranged that each of the drip aprons 45b and c of the middle and rear troughs 24b and c overhangs the rear wall 34 of the trough immediately in front (i.e. 24a and b, respectively), with the discharge edge of each drip apron 45b and 0 being about one inch (1") above the surface of the liquid in the trough 24a, or b in front. Thus fluid pumped into the rear trough 240 from its related pump 40c flows over its front wall 32 onto its apron 45c and into the middle trough 24b, and along with the liquid pumped into the middle trough 24b flows into the front trough 24a. Extending forwardly with a moderate downward slope (i.e. about 20 from the horizontal) from the front top edge 44a of the front trough 24a is the aforementioned discharge apron 26, which likewise extends transversely of the belt 14 and extends moderately beyond each side edge of the panel 12 passing therebeneath. Thus liquid from the three troughs 24a, b, c, flows onto and down the apron 26 and over the front discharge edge 28 thereof to drop onto the panel 12 below.
The afore-mentioned damming spindle comprises a drive shaft 46 mounted parallel to, above, and moderately in front of the discharge edge 28 of the apron 26, and is journal mounted on the supporting frame 23. This shaft 46 is driven through a clutch 50 from a suitable power source such as the motor 52 having a variable speed control handle 54. Secured to the shaft 46 at various apparently random, but predetermined locations along the axial length thereof are a number of mounting blocks 56, each of which carries on the outer or peripheral portions thereof one or more damming shoes 58. So that the angular position of each block 56 as well as its longitudinal position along the length of the shaft 46 can be adjusted, each block 56 is fixed to the shaft 46 by means of a respective hold screw 60.
Each shoe 58 is made of a flexible material and is secured by its leading edge 62 to its related block 56. That peripheral surface portion or portions 64 of each block 56 which backs its respective one or more shoes 58 is curved along an are having the axis of the drive shaft 46 as its center of curvature. The shaft 46 and the blocks 56 with their shoes 58 are so located with respect to the apron 26 that as the shaft 46 rotates (clockwise as seen in FIGURE 2), each shoe 58, as it passes the discharge edge 28 of the apron 26 engages with moderate pressure this discharge edge 28. With the shaft 46 being located above and moderately forward of the discharge edge 28, the exposed or contact surface 66 of each shoe 58, while contacting the discharge edge 28, makes an angle of about ten to twenty degrees with the surface of the apron 26. The effect of each shoe 58 so contacting the apron 26 is to interrupt the flow of liquid off the apron 26 at the area of contact and to actually back up or dam the liquid on the apron immediately behind the shoe 58 which is so contacting the apron 26. When the trailing edge 68 of the shoe lifts free of the discharge edge 28 of the apron 26, this dammed or accumulated liquid flows over the discharge edge 28 in a surge of flow so that a concentrated puddle falls on the panel 12 passing beneath.
After this surge of flow, the liquid flows over this now unobstructed portion of the discharge edge 28 at a more moderate rate. By properly controlling the rate of liquid flow from the pumps 49a, b, and c, this more moderate rate of liquid flow over the discharge edge 28 will be such that the liquid breaks off in random and discontinuous drops and streaks, which fall onto the panel 12. Also, at locations along the apron edge 28 where no shoes 58 make contact, the flow will continuously be in random streaks or drops.
It is readily apparent that the width (dimension parallel to axis of the drive shaft 46) and length (i.e. arc length) of each of these shoes 58 may be varied, and that several shoes 58 may be placed on one block so as to be at the same location along the length of the shaft 58. In addition, these various shoes 58 may be shifted both longitudinally and angularly and may be reap-ranged on the shaft '58 so that a great variety of patterns of these concentrations of the liquid material of the discontinuous applications may be achieved.
After each complete revolution of the shaft 58, the shoes 58 will substantially repeat the distribution of the various concentration of material on the panels 12. ever, not only will there be some moderate variation in these various corresponding concentrations of material from one revolution of the shaft 58 to the next, but the discontinuous and random flow of the liquid over areas of the discharge edge 28 which are not being obstructed by the shoes 58 will not necessarily follow any pattern dictated by the various surges of liquid flow caused by the damming action of the shoes 58. Hence, while an overall pattern does prevail by virtue of the predetermined concentrations of flow, there will be in each location of Howeach panel distinctive variations not existing in the corresponding location of any other portion of any panel.
It will be noted that the front top edges 44b and 44c of the middle and rear trough 24b and 240 are formed with a plurality of randomly spaced shallow (i.e. one quarter of an inch or less) cut-outs 70 of varying length (i.e. the dimension parallel to the edge 4412 or c). The elfect, of this is to localize or direct the liquid from the related trough 24b or 0 along definite channels onto their respective drip aprons 45b or c and then onto the liquid in the adjacent forward trough 24a or b. There is random flow over the portions of the edges 44b and c not so notched so that the three separate sources of liquid mix to some extent in the middle and front troughs 24b and a, but where the liquid fiows through a cut-out 70, it maintains substantial identity or separation. By properly arranging the various cut-outs 70 in relation to the arrangement of damming shoes 58, various concentrations predominantly of one of the three different liquids can be produced. Or if desired, concentrations of the discontinuous coat in which two or three of the liquid sources are substantially present may be achieved.
By varying the relative rates of flow into the three troughs 24a, b, and c, one or two of the sources of liquid of the discontinuous coat may be made to predominate in the pattern of the panels 12. By increasing or decreasing the total flow over the discharge end 28, the amount of discontinuous and random flow over the unobstructed portions of the discharge end 28 may be changed, so as to vary the non-repetitive or random deposits of the material of the second coating, and the amount of liquid in the various surges or concentrations can also be varied.
What is claimed:
1. An apparatus to app-1y liquid in a discontinuous manner onto a substrate member, said apparatus comprising: a liquid dispensing apron having an elongate discharge portion over which liquid is dispensed onto said substrate member, means to feed said liquid onto said apron at a predetermined rate with a predetermined distribution on the apron, means to periodically obstruct and then release liquid flow at said discharge portion at predetermined time intervals and at various predetermined locations at said discharge portion, so that when flow is so interrupted by said obstructing means at any one of said locations, liquid collects at said any one of said locations during such interruption, and upon release of collected liquid at said any one location, there is a concentration of liquid flow from said any one location onto said substrate member.
2. The apparatus as recited in claim 1, wherein said obstructing means comprises a plurality of shoe members each of which engages said apron at periodic interva-ls.
3. The apparatus as recited in claim 2, wherein said shoe members are adjustably mounted 'for circular motion about a rotary axis.
4. The apparatus as recited in claim 2, wherein said shoe members are flexible and are arranged to yieldingly engage an edge of said apron at the discharge portion thereof.
5. The apparatus as recited in claim 2, wherein said shoe members each present a generally planar obstructing surface, which surface when it is adjacent said discharge portion, makes with the surface portion of said apron from which said fluid is discharged an angle less than forty five degrees.
6. The apparatus as recited in claim 1, wherein said feed means comprises a trough having a weir over which liquid flows onto said apron.
7. The apparatus as recited in claim 6, wherein there are a plurality of said troughs arranged for series flow onto said apron, each of said troughs being arranged to contain a liquid of a particular character so that flow from one trough to another and finally onto said apron causes a how onto said substrate member of liquid of varying characteristics.
8. The apparatus as recited in claim 7, wherein at least one of said troughs has a weir, portions of which are of different elevation so that flow from said one trough over its weir is lacking in uniformity of distribution.
9. The apparatus as recited in claim 8, wherein said one trough is disposed for the liquid therefrom to flow into a second trough and finally onto said apron, whereby the liquid from said one and said second troughs maintains a fair degree of identity as it flows over the apron and onto said substrate member.
10. The apparatus as recited in claim 7, wherein the troughs are so arranged that when a first liquid flows from. one trough onto a second liquid in a following trough, the first liquid drops a moderate distance, so that there is little intermixing of said first and second liquids.
11. The apparatus as recited in claim 6, wherein at least one of said troughs is mounted for swing motion about an axis parallel to the length of the trough.
12. The apparatus as recited in claim 1, wherein the discharge portion of said apron comprises a substantially continuous horizontal edge so that moderate liquid flow over said apron will, when unobstructed, be in random paths over said discharge edge, and when obstructed, will be in surges of a predetermined character.
13. An apparatus to apply liquid in a discontinuous manner onto a substrate member, said apparatus comprising: a liquid dispensing apron having an elongate discharge portion over which liquid is dispensed onto said substrate member, means to feed said liquid onto said apron at a predetermined rate with a predetermined distribution on the apron, means to periodically obstruct and then release liquid flow at said discharge portion at predetermined time intervals and at various predetermined locations at said discharge port-ion, so that when flow is so interrupted by said obstructing means at any one of said locations, liquid collects at said any one of said locations during such interruption, and upon release of collected liquid at said any one location, there is a concentration of liquid flow from said any one location onto said substrate member, means to move said substrate member, relative to said apron at a predetermined rate and along a path having a component perpendicular to a general line of elongation of said discharge port-ion, whereby said liquid is distributed onto said substrate member in a suitable manner.
14. A method to apply liquid in a discontinuous manner onto a substrate member, said process comprising:
(a) feeding said liquid onto a discharge apron at a predetermined rate and with .a predetermined distribution so that said liquid flows over a discharge portion of said apron,
(b) periodically obstructing and then releasing flow over said discharge portion at predetermined time intervals and at predetermined locations, so that when flow is so interrupted at any one of said locations, liquid collects at said any one location during such interruption, and upon release of the collected liquid, there is a surge of liquid flow at said any one location, and
(c) moving said substrate member beneath said apron so that liquid flows onto said substrate member in a desired general pattern.
15. The method as recited in claim 14, wherein said predetermined rate of liquid flow is sufficiently moderate so that the flow over said discharge portion, aside from said surges, is irregular and discontinuous.
16. The method as recite-d in claim 14, wherein said liquid comprises several liquid portions having differing characteristics, and one portion of said liquid is fed onto said other portion with an irregular distribution so that 7 8 the liquid portions fed onto said apron maintain a fair References Cited by the Examiner of identity with a generally predetermined dis- UNITED STATES PATENTS n u 10!]. i .17. The method as recited in claim 14, wherein said ggfi ggfl substrate member is initially coated with a first layer 5 2761419 9/1956 Merger et of liquid which forms a friable film, with the result that w hen liquid is applied in a discontinuous manner onto FOREIGN PATENTS said substrate member, said discontinuously applied liquid 191,007 8/ 1964 Sweden.
breaks through said friable film as concentrations of said discontinuously applied liquid flow over said apron onto 10 ALFRED LEAVITT, y Examine!- aid s rate member. E. B. LIPSCOMB, Assistant Examiner.