US1908230A - Spraying apparatus - Google Patents

Description

May 9, 1933. c. E. FAWKES SPRAYING APPARATUS Filed Feb. 16, 1928 l wefiifi Charles Lawn Emma,

aided Wm 11M C59 Patented May 9, 1933 PATENT OFFICE CHARLES ELLIOTT FAWKES, OF CHICAGO, ILLINOIS SPRAYING API'ARATUS Application filed February 16, 1928. Serial No. 254,637.

The present invention relates to apparatus for spraying materials. It has particular reference to the production of a directed spray of liquid materials such as paint, lacquer, varnish, insecticides,,fungicides, etc., but it pertains in general to the dispersion of particles of matter in a fine state of subdivision. For liquids it produces a fine state of subdivision at the same time that it disperses the particles. The apparatus is also adapted for dispersing finely divided materials such as dust or powder and it may be employed in dusting operations which are commonly conducted for the distribution of fungicides and insecticidesin agriculture.

The art of spraying materials is especially well developed and all the common methods includes the releasing of compressed gas to cause dispersion of the liquid as av spray.

Air, nitrogen, etc., either in liquid form or. as gases under pressure, are utilized, usually by feeding the gas in a highly compressed form to a suitable gun or nozzle wherein it is associated with the liquid to be sprayed. The processes all depend upon the energy of compression for producing the spray. Compressors, pressure reservoirs, pressure hose, etc., are necessary for such processes and these may all be eliminated by the present invention. The present hand pumps, such as are used in agricultural sprayers and the like, are also replaced and in some instances even an operator may be dispensed with. New devices on the market utilize a small electrically driven rotary air compressor as part of a spraying gun for supplying compressed air used in spraying. Although such devices have some of the advantages of the present invention they are not adapted to produce suflicient pressure for spraying viscous liquids such as lacquers, varnishes, etc.

Thepresent invention depends upon mechanical energy for dispersing and for producing and dispersing a finely divided material. In case finely divided dust is fed to the device dispersion alone is effected, but when a liquid is employed the device itself g will both produce the fine particles and disperse them in the form of a spray. The mechanical power may be provided by manually operated means, machine power, even compressed air, or preferably electricity- A motor may be provided with a flexible ex- 5 tension cord as a substitute for the now prevalent air hose leading to spray devices. The motor may be small and form an integral part of a hand-held spraying gun.

The invention utilizes centrifugal force to produce dispersion, obtaining it preferably through the medium of a rotary member which is so constructed that it imparts to the material the proper rotation to create a centrifugal force sufficient to form a spray of the desired character. When a rotary member is used the preferable method of feeding material to it is to introduce the material at some point withinthe hurling periphery of the rotary member, but it is to be understood that this is not necessary, nor is it the only method of feeding the material as will readily be explained.

A rotary member fed as above described will produce a circular spray of material in which particles tend to leave the field of rotation in a tangential direction. Since the invention contemplates a directed spray a directing means must be used in combination with the rotor to effect the desired'result. The invention therefore contemplates such a combination. It is to be understood that the term directing means is employed for that part of the combination which effects a directed spray. In spite of the fact that the rotary member itself gives direction to each particle of the spray it is not considered to be the means which directs the spray as a whole. The directing means is considered to be that" member or means which defines the limits of the spray usefully employed. The directing means em-. bodies a baflie, shield, casing, housing or other construction so constituted that it intercepts a substantialportion of the circular spray, leaving a non-intercepted portion of the circular spray bounded by two substantially tangent lines whichportion serves as the spray to be directed for useful purposes.

1 throughthe unbafiled portion of the spray.

Various means may be employed for con-' ducting the aforesaid process of spraying. For illustrating the nature of such apparatus and in order to explain the process and some of its modifications, I have shown in the accompanying drawing a number of devices capable of operating according to the present invention. In the drawing:

Figs. 1 and 2 are respectively front and side views of a device containing a brushtype rotor.

Figs. 3 to 7 inclusive illustrate other types of rotors which may be employed in place of the brush of Fig. 2.

The apparatus and the process will be explained with particular reference to the spraying of nitrocellulose lacquers (which is representative of the materials most difficult to manipulate) ,but it should be remembered that this example is not to be considered as a limitation.

I have observed that if a liquid, such as a nitrocellulose lacquer of viscosity below one hundred centipoises be subjected to a peripheralvelocity of 100 feet per second or more, and then be released, centrifugal force will create and hurl finely divided particles in a tangential direction in Y the form of a mist or spray comparable to that obtained with air-operated spraying appa-- ratus. It is not important how the liquid is given this rotational force nor how it is discharged to produce such an atomized spray. Nevertheless, there are certain practical features of importance which are necessary tobe considered in the construction of apparatus. A mechanical rotor is the referred means for securing the rotational eld and various forms may be provided. The bafiies or directing means are preferably formed as housings for the rotors, and are provided each with an opening for a desired spray to escape. i

Figs. 1 and 2 illustrate a rotor which may be termed the radial type. An intercepter is used, which functions as a directing means. A motor shaft 32 projects into the casing 30 and carries a' rotating member thereon which is disk-like in construction. The type of disk which 'I prefer to use is one which provides a large surface extending radially. Hence I employ a hub 33 mounted on the shaft and from the hub to the eriphery of the disk I provide radial mem ers which offer such a large surface. These are herein ex mpl fie by brist es 3% made of steel or other similar material which will provide a smooth surface, and also a large number of points at the periphery. An ordinary steel wire brush ,wheel such as is now found in the market is satisfactory. The bristles extend almost to the periphery of the casing, there being very slight-clearance which is shown in exaggera tion in the drawing and designated 35.

In the present instance liquid is fed into the device on the outer side of the casing 30, at the center thereof, by means of a conduit 36 from a reservoir 37 through control valve 38.. The location of the feed at the center tends tomake a balanced peripheral spray when no baflle acts. Where part of the spray is baflled and returned to the periphery this balance is somewhat distorted and suitable change in the location of the feed will tend to correct any undesirable variations in the intensity of the directed spray. An adjustable eccentric feed may be made to produce desired effects or changes, the adjustment being both radial and arcuate.

The periphery of the casing has an open ing therein which is designated 39., It is so located and dimensioned that it permits the desired width of spray to issue. It is to be noted that the elements of the spray issue substantially tangentially from the rotor, and it is preferable to omit any noise or like construction as the walls of such a device would merely afford a surface where sprayed liquid may accumulate and finally drip off with possible injury to the work. The spr ay isindicated at 4.0 issuing between the tangential bounds 41 and 42.

- The interior of the casing intercepts the material in the remainder of the, circular spray and this forms a film in the casing. Because the clearance is small the ends of the bristles constantly clean this film of ma terial away and throw it out of the opening 39 when the bristles pass it. The construction prevents the accumulation of any liquid in the device and it may be operated at any angle in the same manner as the usual handheld air-operated spray gun.

The bristles provide a large surface, and it is assumed that each is covered with a film of the liquid which travels rapidly and with accelerationas the end of the bristle is approached. It is further assumed that one of two actions takes place: either the film is stretched out and becomes very thin at the end, or it is constantly broken into small bands which leave the bristle as particles of mist. Thisrefers to the liquid which is fed in at some point within the periphery of the rotor, and not to the liquid removed fromthe inside wall of the casing. Suclrparticles of liquid as do not first strike a bristle must eventually encounter a rapidly moving bristle which will cut the particle and divide it. This process will recur continually until a fine mist is produced at the periphery.

Although the bristles provide one form of disk rotor of the radial type the invention is not limited to it. A flat smooth plane surface may be employed and may be mounted perpendicularly to its plane surface as shown at 50 in Fig. 3 or it may be mounted on an angular axis as shown at 51 in Fig. 4. The disk of Fig. 3 may be provided with a dished periphery as shown at 52 in Fig. 5 to throw the mist in a distorted spray.- Fig. 6 shows a multiplicity of slightly spaced disks 53, 54 and 55 and these may be mounted as are the single disks in Figs. 3 and 4. They are shown mounted on a perpendicular axial shaft. 56. Various contours may be provided at the periphery or throughout the disk in order to vary the character of the spray. It will be observed that the angularly mounted disk of Fig. 4 will provide a .wider and perhaps more flaring spray than centrifugal distributing rotary the disk of Fig. 3.. The disk may be so shaped that the particles leave it at various angles within a limited range. For .example, the disk 57 of Fig. 7 shows radial corrugations 58 to effect this. a

The bristle type of rotor offers another advantage. When a liquid is used in which there are solid suspended particles, as for example a pigment, as in paints or lacquers, there is no danger of separation of solid 2nd liquid by selective action of centrifugal orce.

It is to be noted that in the radial type of rotor each particle of material has a radial as well as a rotary motion, which when compounded together give a resulting path which deviates from a true circular motion. The actual direction of a particle in the spray is dependent upon the actual direction of the particle at the instant thatit is released from the rotor. The shorter the radial travel, the less will be the deviation from a tangent.

The invention is susceptible tothe provision of air or gas supply to the spraying device, not, however, as a spraying means, but as a vehicle. For example, in Fig. 5 a current of air carrying dust may be supplied through conduit 36. Or gas may be sup plied to furnish a hot medium or envelope to follow along with the spray. in cases where a material is employed which is liquid when hot and susceptible to congealing when cold after being sprayed, such for example as the spraying of glue solutions with steam or hot gas, as described in my copending applications Ser. No. 251,665, filed Feb. 3, 1928, and Ser. No. 291,476, filed July 9, 1928.

I claim:

1. A liquid spraying device comprising a member, means to feed liquid to the center of said member, a housing about said member having a limited opening therein in the path of liquid centrifugally sprayed by said member, said opening permitting escape of spray for application and said housing collecting liquid elsewhere sprayed by said member, said housing and said member being separated by a minimum clearance space whereby liquid adhering to the housing is dragged bysaid member. v

2. A liquid spraying device comprising a centrifugal distributing rotary member, a housing surrounding said member with a minimum of clearance at the periphery of said member, said housing having a limited opening in the line of the periphery of said member, and means to feed liquid to the member at the center thereof.

3. A liquid spraying device comprising a centrifugal distributing rotary member of disk-like shape, a housing surrounding said member with a minimum of clearance at the periphery of said member. and at the sides of said member, said housing having a limited opening in the line of the periphery of said member, and means to feed liquid to the member at the center thereof.

4. A liquid spraying device comprising a centrifugal distributing rotary member comprising bristle-like members extending radially from a central hub, a housing surrounding said member with a minimum of clearance at the periphery of said member, said housing having a limited opening therein in the line of the periphery of said member, and means to feed liquid to the hub at the center thereof for centrifugal flow to the bristles of said member.

5. A liquid spraying device comprising a centrifugal distributing rotary member of disk-like shape comprising bristle-like members extending radially from a central hub, a housing surrounding said member with a minimum of clearance at the periphery and at the sides of said member, said housing having a limited opening in the line of the periphery of said member, and means to feed liquid to said member at the .center thereof.

6. A portable liquid spraying devicecomprising in combination a circular housing, a dislclike rotary distributing member mounted in said housing with a limited clearance space between the member of the housing, said housing having an opening therein in line with the periphery of said member, a motor attached to said housing having said rotor mounted on the motor axis, and a conduit connected to the housing to introduce liquid to the center of said member to be sprayed by rotation of the enclosed member.

7. A liquid spraying device comprising a centrifugal distributing rotary member, means to feed liquid to said member Within the periphery thereof, a housing about said member having a limited opening therein in the path of liquid centrifugally sprayed by said member, said opening permitting escape'of spray for application and said 5 housing collecting liquid elsewhere sprayed by said member, said housing and said member being separated by a minimum clearance space whereby liquid adhering to the housing is dragged by said member.

8. A liquid spraying device comprising a.

centrifugal distributing rotary member, a. housing surrounding said member with a minimum of clearance at the periphery of said member, said housing having a limited opening in the line of the periphery of said member, and means 1- to feed liquid to the member within the periphery thereof.

9. A liquid spraying device comprising a centrifugal distributing rotary member of disk-like shape, a housing surroundingsaid member with a minimum of clearance at the periphery of said member and at the sides of said member, said housing having a limited opening in the line of the pe- 5 riphery of said member, and means to feed liquid to the member within the periphery thereof. I

10. A liquid spraying device comprising a centrifugal distributing rotary .member comprising bristle-like members extending radiallyfrom a central hub, a housing surrounding said member with a minimum of clearance at the periphery of said member, said housing having a limited opening therein in the line of the periphery of said member, and means to feed liquid to the hub thereof for. centrifugal flow to the bristles of said member. r

11. A liquid spraying device comprising 40 a centrifugal distributing rotary member of disk-like shape comprising bristle-like members extending radially from a central hub, a housing surrounding said member with a minimum of clearance at the periphery and at the sides of said member, said housing having a limited opening in the line .of the periphery of said member, and means to feed, liquid to said member within the perlphery .thereof. 12. A portable liquid spraying device comrising in combination a circular housing, a disk-like rotary distributing member mounted in said housing with a limited clearance space between the member of the housing, said housing having an-sopening therein in line with the periphery of-said member, a motor attached to said housing having said rotor mounted on the motor axis, and-a conduit connected to the housing to introduce liquid Within the periphery of said member to be sprayed by rotation of the enclosed member. y In testimony whereof I have hereunto aflixed my signature.

" CHARLES ELLIOTT .FAWKES.

Patent No. 1,908,230.

CERTIFICATE OF CORRECTION.

' May 9, 1933.

CHARLES ELLIOTT FAWKES.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page ,1, line 19, for "includes" read "include"; page 2, line 56, after "means." insert the sentence "A cylindrical casing 30 is mounted along side and rigid with a motor casing 31."; and line 497,, for "noise" read "nose"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of July, A. D. 1933.

M. J. Moore.

(Seal) Acting Commissioner of Patents.

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