Spray apparatus

April 3, 1962

3,027,870

H. G. SCHIRMER

SPRAY APPARATUS

Filed July 5, 1957

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3,927,870

Patented Apr. 3, 1962

United States Patent Office and the following specification wherein a preferred embodiment is illustrated and described.

In the drawings:

FIG. 1 is a perspective view of devices incorporating the invention used with a conventional spray nozzle;

FIG. 2 is a view of the interior of the device illustrated in FIG. 1, along line 2—2;

FIG. 3 is a fragmentary vertical sectional view of FI&lt;j. 1 taken along line 3—3;

FIG. 4 is an enlarged fragmentary view, partly in section, of FIG. 3 showing certain parts thereof in greater detail; and

FIG. 5 is a diagrammatic view in elevation of the device in use in a continuous spraying operation.

Referring to the drawings wherein like characters denote similar parts throughout the several views, there is shown a spray nozzle 1 of conventional form through which the liquid to be sprayed is forced under air pressure positioned within a hollow casing or hood 2. The hood may be attached to the nozzle, if desired, to provide a mobile unit.

In the embodiment illustrated, the hood is in the shape of a hollow, inverted, truncated pyramid having four walls 3 converging downwardly towards each other and meeting to define a rectangular opening 4 through which a liquid 5 from the spray nozzle is discharged on to the surface being sprayed. The hood may be of a variety of forms, as, for example, an oval, a truncated cone, or a polyhedron of other configuration.

As the liquid 5 is discharged from the spray nozzle in the form of finely divided particles, it passes through the opening 4 at the bottom of the hood defined by -the lower peripheral edges of the converging walls 3 and is deposited upon the surface below to be sprayed. Because it is in a finely divided state, and under pressure, not. all of the liquid ejected from the spray nozzle is deposited on the surface being sprayed. Some of it escapes into the surrounding atmosphere; another part bounces back from the surface being sprayed and collects upon the hood, nozzle and other adjacent surfaces of the apparatus. Some of the sprayed liquid collects on the inner surfaces of walls 3 and then rolls downwardly towards the bottom edges of the walls towards the opening 4. When sufficient amounts of the sprayed liquid have collected on these surfaces, it will drip onto the surfaces being sprayed below.

This problem is accentuated when the hood is also being used as a mask or stencil to define the pattern to be sprayed, as for example in connection with apparatus similar to that illustrated in FIG. 5. When the hood is being used in this manner, it is necessary that the spray 5 discharged from the nozzle be larger than the opening 4 in the hood so that spray will fill the opening as it passes through. Consequently, the edges of spray will strike directly upon the inner surfaces of the walls 3 of the hood and a considerable amount of the liquid will collect rapidly on the walls. It is apparent that this liquid must be removed quickly and effectively.

In accordance with the invention, sprayed liquid which collects on the walls of the hood and other adjacent surfaces and which rolls down to the bottom edges of the hood is collected by providing porous hollow members 6, such as a perforated tube, on the bottom edges of the hood walls into which the liquid may be drawn by suction. The invention also contemplates the use of a wicking member 7, as will be more fully explained below, positioned on the bottom parts of the apparatus to hold liquid and to conduct it to openings 8 in the hollow member by capillarity where it is drawn into the interior of the'hollow member by the. suction.

As illustrated in the, drawing, these structural arrangements and . the advantages foliotying therefrom . may be

3,027,870 SPRAY APPARATUS

Henry G. Schinner, Flushing, N.Y., assignor to Personal Products Corporation, a corporation of New Jersey Filed July 5, 1957, Ser. No. 670,088

Claims. (CI. 118—504)

This invention relates to spray devices and more particularly to devices for controlling and confining the spray and the spray patterns of spraying apparatus, such 10 as spray guns. ..,. _Λ

In a typical spraying operation, the liquid to be sprayed is forced through a jet or nozzle under pressure which breaks it down into finely divided particles so that it emerges from the nozzle in a mist-like form. Because it la is in a finely divided state, and under pressure, not all of the liquid emerging from the nozzle is deposited on the surface to be sprayed. Some of its bounces back from . the surface and escapes into the surrounding atmosphere. ' Another part drifts off and is deposited on other surfaces adjacent the surface being sprayed where it collects. In many instances, these incidents of spraying are undesirable because a variety of spraying operations require controlled application of the sprayed liquid to the surface .sprayed. In some cases, it may be necessary to apply the sprayed liquid over the surface uniformly; in others, to apply the sprayed liquid to the surface in a partcular pattern as, for example a line or broad band with sharply defined edges; and in still others, the spraying operation may require rapid removal of any excess sprayed liquid to avoid dripping and spattering.

In attempts to overcome these problems, hoods and similar devices have been .used to confine and control the spray particularly when the spraying is being performed _ggin closed areas. Although the use of hoods has aided in overcoming some of the problems, others remain. For example, the hoods themselves have surfaces upon which some of the sprayed liquid may deposit, collect and then drip off. This is particularly troublesome when the sur- ₄₍₎face being sprayed is positioned below the spray nozzle; e.g., where the spraying operation involves spraying a horizontal surface. The liquid which has collected ..on the hood surfaces may fall upon the surface being sprayed. When the spraying operation involves the use _4gof a mask or stencil to define a sprayed pattern of particular form, or the operation involves the application, of the liquid sprayed-in controlled amounts, it is apparent that such dripping must be avoided.

In those operations which involve spraying a pattern or 50 design on a surface, it is desirable that the stencil or mask used be so constructed as to provide a clear, well-defined pattern. The -part of the spray which does, not pass through the opening in the stencil or mask should be . effectively removed before it accumulates in such quanti- ³⁵ties as will result in its dripping on the surface sprayed. A partcularly suitable device of this nature would provide for rapid removal of this part of the spray.

It is an object of this invention to provide a device for ₆θ confining and collecting surplus sprayed liquid resulting from spraying operations. It is another object of this invention to provide a hood, which can be used in spraying operations to confine the. sprayed liquid. It is, still another object of this, invention to provide a device which 55 also-can be used as a mask or stencil for defining, the,pattern sprayed. It is a still further object of. this invention to provide a device;which can be employed in spraying operations involving spraying horizontal surfaces to prevent. dripping of the sprayed liquid on such surfaces. 70 Other and further objects of_; the invention will become . apparent: from. a consideration of the attached drawing

8,027,870 obtained by attaching a porous, hollow member, such as a tube, to the bottom edges of the hood walls at the opening 4 through which the sprayed liquid is discharged. If the opening is rectangular shaped, as illustrated, or of similar form, each side may be provided with a separate 5 tube and all tubes connected to each other to form a continuous passageway around the opening. If the opening is circular or oval or of a similar form, one continuous tube of like shape may be used. The tubes 6 are connected to return tubes 9 which conduct the collected liquid 10 to a master return tube 10 for return to the system for reuse, or to storage, or to waste, as desired.

The openings 8 in the tubes 6 are preferably on the surface of the tubes facing towards the interior of the hood so that the liquid rolling down the inner surface of the 15 hood walls will be quickly drawn through the openings into the tube by the suction. These openings may be a series of ports extending the length of the tubes, a thin, longitudinal slot or of other suitable forms. The hollow member may be a porous ceramic tile or of similar ma- 20 terial. The openings in the tube should be sufficiently large to permit the liquid to enter the tube readily, but not so large that it would be difficult or uneconomical to maintain adequate suction to draw the liquid into the interior of the tubes. 25

As the sprayed liquid is ejected from the spray nozzle, some of it deposits on the inner surface of the walls of the hood. When sufficient amounts of it have collected, it rolls downwardly towards the lower edges of the hood. VZhen the rolling liquid contacts the openings 8 in the 30 tubes 6, it is drawn into the interior thereof by the suction into the return tubes 9.

Some of the sprayed liquid, including pail of that which bounces back from the surface being sprayed and that which has escaped into the surrounding atomsphere, 35 collects on the bottom edges 11 of the tube. This liquid will not be drawn into the tubes by the applied suction if it does not contact the tube openings. Consequently, it will collect and drip from the tubes. This is also true of liquid which collects on the outer surfaces of the tubes 40 and adjacent surfaces of the hood walls. In accordance with the invention, the liquid which collects on these surfaces can be drawn into the tubes by the suction by employing an element which acts as a wick to pick up this liquid and conduct it to the tube openings. _4g

As illustrated in FIG. 4 of the drawings, wicking element may extend from adjacent the lower inner edges of the hood walls 3 downwardly over the openings 8 in the tubes 6, around the bottom of the tube and then upwardly a short distance along the outer surfaces of the ₅θ walls. It is not necessary, however, that the wicking element cover the openings in the tubes; it may extend to the edges of the openings or in such proximity to the openings to bring liquid held by it under the influence of the suction to enable the suction to draw the liquid through the _ggopenings into the tubes. The wicking material may be applied to the wall and tube surfaces by means of an adhesive, hooking devices, snaps, pins, or in any other suitable manner. Any suitable material which provides the wicking-like action may be used. A number of plies _e0of woven textile fabric such as gauze or a nonwoven fabric are suitable because they may be quickly replaced, if necessary. Liquid which contacts the wicking element will be retained by the element by virtue of its capillary properties and will be conducted to the openings in the _ggtubes under the influence of the applied suction.

In FIG. 5, the device is shown in use in connection with an operation involving spraying the surface of a horizontally moving web. A web 12 of fibers is fed from a feed roll 13 to an endless supporting belt 14 under the γθ spray nozzle 1 and then to a driven take-up roll 15. The hood 2 is placed above the web a sufficient height to permit the web to move freely below. The spray nozzle is directed downwardly towards the upper surface of the web and is positioned inside the hood so that the spray 75 will be confined within the hood as it passes through to the web below. Liquid sprayed from the nozzle is discharged through the opening in the bottom of the hood and is deposited upon the upper surface of the web moving below.

In the illustration, the hood is also used as a mask. The opening in the bottom of the hood is positioned over the center of the web so that the pattern which is sprayed upon the web will be limited to the center portion and so that the edges of the web will be unsprayed. To insure that the sprayed liquid is deposited on the web evenly and in uniform concentrations, it is necessary for the spray to pass through the opening in the hood in regular and in uniform concentrations. To this end, the spray pattern from the spray nozzle and the position of the nozzle in the hood is regulated so that edges 16 of the spray strike the inner surface of the converging walls of the hood. Consequently, a large amount of the sprayed liquid accumulates rapidly upon these surfaces and rolls downwardlly towards the bottom edges of the hood. When the sprayed liquid contacts the wicking element, it is picked up by the element, as best seen in FIG. 4, and directed to the openings in the tubing positioned around the hood opening. It is drawn into the interior of tubes 6 by the suction and then passes from the tubes to the collecting tubes 9 communicating therewith. The pattern sprayed upon the surface of the moving web is in the form of a continuous band.

In the example, water is lightly sprayed in the form of a fine mist upon a web under two pounds of pressure through a hood having an opening one and three-eighth inches square. The sprayed area is a continuous band one and three-eighth inches wide. Copper tubes, one and three-eighth inches long having an outside diameter of one-quarter inch and an inside diameter of threesixteenth inch is attached to each side of the hood opening. Each tube has eight aligned holes, one-eighth inch in diameter, equally placed throughout its length. The tubes are positioned so that the line of holes face towards the center of the hood opening. Each tube is covered with a wicking element consisting of absorbent cotton fabric sheeting. The amount of suction applied to draw the excess sprayed liquid into the tubes is adjusted as required.

The device may be used in spraying operations which are intermittent instead of continuous. For example, the web of material to be sprayed may be moving intermittently and the surface of the web directly below the spray nozzle and the hood sprayed each time the web is halted in its movement. In this manner there may be provided on the web patterns of different configurations in a repeating fashion depending upon the configuration of the opening in the hood.

The hood may be attached to the spraying apparatus, or to a mobile spray gun, so that the entire assembly may be moved freely; or it may be attached to other parts of the equipment with which it is used.

It is to be appreciated that the invention is not limited to the specific forms illustrated and described above and that changes may be made without departing from the spirit of the invention.