US3120346A

US3120346A - Rotary spray devices

Info

Publication number: US3120346A
Application number: US234356A
Authority: US
Inventors: Ernie D Willhoite
Original assignee: AMF Inc
Current assignee: AMF Inc
Priority date: 1962-10-31
Filing date: 1962-10-31
Publication date: 1964-02-04
Anticipated expiration: 1981-02-04

Description

1964 D. WILLHOITE I 3,120,346

ROTARY SPRAY DEVICES Filed Oct. 31, 1962 2 Sheets-Shet 1 Fig.4

I NTOR. ERNIE 0. LL HO/TE Feb. 4, 1964 Filed Oct. 31, 1962 fig.

E. D. WlLLHOlTE ROTARY SPRAY DEVICES 2 Sheets-Sheet 2 INVENTOR. EEN/E 0. W/LLHOI TE aw h ATTORNEYS United States Patent 3,12%),346 RUTARY SERAY DEVIQES Ernie D. Wiilhoite, Houston, Tex, assiguor, by mesne assignments, to American Machine it Foundry Comparty, a corporation of New Jersey Fiietl (st. 31, 1%2, Ser. No. 234,356 16 Claims. (Qi. 239-215) This invention relates to rotary spray devices and, more particularly, to an improved fluid-driven rotary spray device which, while not limited to such uses, is particularly effective in spraying the inner surfaces of pipe and tubing.

It has long been proposed to construct spray devices in such fashion that the material being sprayed is discharged from a rotor driven by compressed air or other equivalent fluid under pressure. For some types of spraying operations, satisfactory fluid-driven rotary spray devices have been proposed heretofore. For other types of spraying operations, however, prior art devices of the fluid-driven type have been largely unsuccessful. This is particularly true, for example, in the case of devices to be employed for spraying relatively viscous materials and in the case of devices required to spray laterally relative to their axis of rotation.

Lack of success of prior-art rotary spray devices in some fields results from several difliculties. One such difficulty is the problem of devising a fluid-driven structure which is adequately small, yet can be driven at relatively high rates. Another problem is obtaining adequate and uniform feeding of the material to be sprayed, and accomplishing good atomizing thereof. A particularly vexing problem arises in so designing the device that the material being sprayed does not enter the region of the rotary bearings, for example. Difficulties are also encountered in constructing a rotary spray device which, although relatively small, is capable of spraying materials of relatively widely varying viscosity.

The problems just mentioned are encountered, for example, in devising a rotary spray device for the internal coating of pipe and tubing employed in oil and gas wells. Such tubular goods must be coated with great uniformity and accurate control of the coating thickness, using coat ing compositions of various viscosities and which frequently have a substantial solids content which varies between the different compositions. Coating must be accomplished by spraying laterally relative to the axis of the work, the spray device being passed axially through the work one or more times. The nature of the material being sprayed is such that, to be effective, the spray device must rotate at relatively high speed and deliver the sprayed material at a high rate, wi h uniform and effective atomization, over long periods of use. The coating materials employed are such that entry thereof into the bearing areas, for example, of the spray device will render the same inoperative.

A general object of the invention is to devise an improved rotary spray device.

Another object is to provide a fluid-driven rotary spray device which is especially useful for the internal coating of tubular work.

A further object is to provide a high speed rotary spray device which is driven by air or other fluid under pressure and is capable of accomplishing uniform and effective atomization of relatively viscous materials sprayed outwardly from the axis of rotation of the device.

Yet another object is to devise a fluid-driven rotary spray device so constructed that the material being sprayed does not enter the region of the bearings of the device during its operation.

A still further object is to provide such a device which is capable of spraying coating materials of various viscosities and solids contents.

In order that the manner in which these and other objects are attained in accordance with the invention can be understood in detail, reference is had to the accompanying drawings, which form a part of this specification, and wherein:

FIG. 1 is a longitudinal sectional view of a rotary spray device constructed in accordance with one embodiment of the invention;

FIGS. 2, 3 and 4 are transverse sectional views taken on lines 2-2, 33 and 44, respectively, of FIG. 1;

FIG. 5 is a side elevatio-nal View of the rotary nozzle member of the device of FIG. 1;

FIGS. 6 and 7 are three-dimensional diagrams illustrating the manner in which certain ports of the nozzle member of FIG. 5 are inclined transversely and axially;

FIG. 8 is a longitudinal sectional View of a revolving spray device constructed in accordance with another embodiment of the invention;

FIGS. 9, "10 and 11 are transverse sectional views taken, respectively, on lines 9-9, 19-10 and 11-11, FIG. 8;

FIG. 12 is a side elevational view of the nozzle member of the device of FIG. 8;

FIG. 13 is a fragmentary transverse sectional View of a modified form of the device of FIG. 8; and

FIGS. 14 and 15 are fragmentary enlarged elevational views illustrating the distribution of certain ports employed in the device of FIG. 13.

Turning now to the drawings in detail, and first to FIGS. 1-7 thereof, it will be seen that the embodiment of the invention illustrated comprises a hollow rotor 1, a supporting and fluid supply structure indicated generally at 2, and a rigid assembly 3 of concentric tubes which is effective both to conduct fluids to the spray device and to allow the same to be manipulated relative to the Work.

Rotor 1 includes an integrally formed nozzle member 4 and a tubular extension 5. Nozzle member 4 is generally cup-shaped, being closed at its tip and having an open, exteriorly threaded end 6, the tubular portion between the tip and open end of the nozzle member being of adequate length to provide space for an annular transverse exterior portion 8. As shown in FIGS. 2 and 3, both nozzle member 4 and extension 5 are of circular transverse cross-section. At one end, extension 5 is provided with internal threads engaged with the external threads of the open end of the nozzle member. Exteriorly, the extension 5 presents a right cylindrical surface 9.

In an area spaced axially from its internally threaded end, extension 5 includes a portion 10, of smaller internal diameter, disposed between two portions of larger internal diameter, the latter portions accommodating rotary antifriction bearings 11 and 12, respectively, which may be conventional ball bearings, of any suitable type, arranged with their outer races fixedly retained by the surrounding portions of extension 5. It will be understood that bearing 11 is forced axially into place, shouldering against the end of portion 149, before nozzle member 4 is attached to extension 5.

Extension 5 is provided with a plurality of circumferentially spaced axially extending bores 13 which all open through end faces 14 of the extension and communicate with the space within extension 5 adjacent the open end of nozzle member 4.

Supporting and fluid supply structure 2 is mounted on tubular assembly 3 and carries rotor 1. Though structure 2 is movable in the sense that it can be manipulated by assembly 3, structure 2 can be considered as stationary relative to rotor 1.

Assembly 3 includes a central tube 15 and an outer tube 16, both exteriorly threaded at their tips. Structure 2 comprises a rigid tubular central member 17 having an intermediate, exterior, transverse, annular flange 18, an exteriorly threaded tip 19, and an exteriorly threaded end portion 20 opposite tip 19. A tubular connector 21 is employed to attach end portion 2t? of member 17 to the tip of tube 15, the connector having a larger internally threaded end engaged with the threaded tip of tube 15, and a smaller internally threaded end engaged with threaded end 20 of member 17 Adjacent the tip of tube 15, connector 21 accommodates a flow control ring 22 of accurately predetermined internal diameter. Material to be sprayed is supplied under pressure via tube 15, passes through ring 22 and is conducted into member 17 via plain bore 23 of connector 21.

On the side of flange 18 facing tip 19, member 17 has a plain cylindrical outer surface. Before nozzle member 4 is attached to extension 5, but with bearings 11 and 12 in place, member 17 is passed through the bearings with the inner races of the bearings engaging the outer surface of member 17 in a friction fit and with the inner race of bearing 12 shouldering against flange 13. There is then attached to tip 19 of member 17 a tubular discharge member 24. At one end, member 24 is interiorly threaded to engage threaded tip 19. At its other end, member 24 has a flat, circular, transverse end face 25. End face 25 is of larger diameter than the main body of member 24, so that a transverse, circular flange 26 is provided, defined by the peripheral portion of end face 25, a short cylindrical outer surface 27 and a frusto-conical surface 28. Member 24 has an axial bore 29 which opens centrally through end face 25 and is of the same diameter as the bore of member 17.

Internally, nozzle member 4 has a plain cylindrical surface portion 30 adjacent the closed tip of the nozzle, and a plain cylindrical surface portion 31 adjacent open end 6, surface portions 30 and 31 being interconnected by a frusto-conical surface portion 32 which tapers inwardly toward the open end of the nozzle member. Surface portion 31 is of such diameter as to pass flange 26, so that the nozzle member can be attached to extension after the extension and bearings have been assembled on member 17 and member 24- has been secured to tip 19. Surface portion 30 is relatively short, axially of the nozzle member, and is so located as to extend from a point spaced beyond end face 25 to a point spaced in the opposite direction beyond flange 26. The closed end of nozzle mem her 4 presents a conical outer face 33 and an inner face which includes a conical portion 34 tapering inwardly toward the center of bore 29. The base of conical portion 34 joins an annular, flat, transverse surface 35 which intersects surface portion 39 at right angles. Surface portions 39, 31, 32, 33 and 34- are all centered on the axis of bore 29.

Structure 2 is completed by an outer tubular member 36 and a member 37. Member 37 includes a cylindrical portion 33 having a central bore embracing member 17 on the side of flange 18 opposite rotor 1, portion 33 being clamped against flange 18 by a nut 39 engaged with the exterior threads of portion 24} of member 17. End face 40 of portion 38, directed toward rotor 1, is a flat, circular surface extending transversely of member 17 and spaced axially from end face 14 of extension 5. Portion 38 of member 37 is exteriorly threaded. Tubular member 36 is internally threaded at both ends, one end being engaged with the threads presented by portion 38 and the other end with the threads presented by the tip of outer tube 16 of assembly 3.

Portion 38 is provided .with a plurality of axially extending, circumferentially spaced bores 41 which place the annular space between members 17 and 36 in communication with the space between end faces 14 and 40.

Member 37 includes a tubular extension 42, in the form of a right cylinder, which projects from end face 40 toward flange 7 and is concentric with member 17. The inner diameter of extension 42 is slightly larger than the outer diameter of extension 5, so that a small clearance or annular space 43 is provided between extensions 5 and .2, which space communicates directly with the space between end faces 14 and 48.

In that cylindrical area of portion 3 which generally surrounds flange 25 of discharge member 24, the tubular portion of nozzle member 4 is provided with a plurality of spray discharge ports 44. In a second area of portion 8, spaced axially away from flange 26 and toward the open end 6 of the nozzle member, the tubular portion of the nozzle member is provided with a plurality of reaction fluid discharge ports 45. Ports M are angularly spaced from each other so as to be distributed generally circularly about the nozzle member. Similarly, ports 45 are angularly spaced from each other. The ports 44 and 45 can be distributed in various patterns. Advantageously, the ports 44 can be arranged in a plurality of circular series, with the series spaced axially from each other, and the ports 45 can be similarly arranged. Thus, in the embodiment illustrated, the ports 44 are arranged in four circular series, and the ports 45 are arranged in two circular series. Commencing at the tip of nozzle member 4, the first series of ports 44 opens into the interior of the nozzle member near surface 35, and the last series of ports 44 is spaced a material distance from flange 25 toward the open end of the nozzle member. Located in the circular area of portion 3 immediately adjacent flange 7, ports 45 are spaced a substantial distance from ports 44.

Ports 45 are in the form of straight bores nngularly disposed in such fashion that their axes slant outwardly toward the open end of the nozzle member and, if projected onto a transverse plane at right angles to the axis of rotation of rotor 1, extend chordwise of the circle defined by the intersection of that plane with the outer surface of portion 3. Thus, as illustrated in FIG. 7, the axes of bores 45 can slant outwardly toward the open end of nozzle member 4 at 10 and can be so disposed that, if projected as just mentioned, lie at 45 relative to a diameter of the outer surface of portion 8.

As indicated in FIG. 6, ports 44 are also in the form of straight bores and are angularly disposed the same as are ports 45, except that ports 44 are slanted outwardly toward the closed tip of the nozzle member.

Assembly 3, connected to the rotary spray device in such fashion as to allow positively controlled manipulation thereof, constitutes what is commonly termed a lance in the pipe coating industry. By valved means not shown, the space between tubes 15 and 16 is connected to a source of reaction fluid under pressure. Thus, the reaction fluid can be compressed air at 30-55 psi. The material to be sprayed, which may be a relatively viscous, high solids content, synthetic resin coating material, for example, is supplied under pressure via tube 15.

Compressed air supplied via tube 16 passes through member 36 and thence through bores 41 into the space between faces 14 and 40. A relatively small proportion of the air escapes via space 43, discharging forwardly around flange '7. Most of the air passes forwardly through bores 13 and into the open end of the nozzle member 4, so that the nozzle member is thus filled with air under pressure. Assuming that material to be sprayed is not yet supplied via members 17 and 24, the compressed air will escape outwardly from the nozzle member 4, both via ports 4-4 and via ports 45. Because of the angular disposition of the ports, escape of the air therefrom, occurring at a reasonably high velocity, creates reaction forces which cause rotor 1 to rotate about its longitudinal axis on bearings 11, 12. Such rotation is at a relatively high speed, in the range of 15,00025,000 rpm, for the embodiment illustrated when made in the relatively small sizes used for coating oil and gas well tubular goods.

The fluid material to be sprayed is supplied under pressure through tube 15, passing through ring 22, bore 23, the bore of member 17 and bore 29 of member 24, so as to discharge directly into the space between transverse faces 25 and 34. With nozzle member 4 rotating at high speed as a result of discharge of air from ports 45, the

spray material discharged from bore 29 flows radially outwardly by centrifugal force, spreading over surface 34 and being discharged via spray ports 44. Depending upon the viscosity of the spray material and the pressure and rate at which it is supplied, the spray material may escape via only the ones of ports 44 nearest the closed end of the nozzle member, or may be discharged at progressively lower rates through those circular series of ports 44 spaced in succession away from the closed end of the nozzle member. Thus, the centrifugal spraying action accomplished during operation of the device is self compensating, the spray material being automatically directed to a larger number of the spray ports when that condition is required.

Assuming that the spray material flows centrifugally outwardly over surface 34 at a rate greater than can be accommodated by the first circular series of ports 44, the spray material forms cylindrically on surface 38, spreading to the right (as the device is viewed in FIG. 1) and therefore finding its way to the second, third and fourth circular series of ports 44. Since surface 32 tapers inwardly toward the open end 6 of the nozzle member, centrifugal force tends to oppose any spray material which reaches the junction between surfaces 39 and 32.

An important feature of the invention is the inherent ability of the device to exclude the spray material from the area where bearings 11 and 12 are located. Presence of spray material in the bearings would give serious trouble in operation, particularly since rotation of the rotor depends upon the driving action of the reaction fluid discharging from ports 45, so that starting torques are low. The self compensating action just described, and the frusto-conical configuration of surface 32, both act to prevent travel of the spray material toward the bearings. This action is further aided by the fact that the air is supplied to ports 45, under pressure, from the open end of the rotor toward the spray ports 44. Finally, the location of the reaction fluid discharge ports 45 is such that any stray quantities of spray material will be discharged through the ports 45.

When the device is used to coat the interior of a pipe, it is first run into the pipe by manipulation of the lance structure 31, no spray material being supplied at this time. Then, with both compressed air and spray material supplied via tubes 16 and 15, respectively, the lance structure 3 is moved in the opposite direction through the pipe, so that the device travels from left to right as viewed in FIG. 1. Since, for this direction of axial travel, the ports 45 lead, the discharged air or other reaction fluid is directed onto the work surface before the spray material is applied. The air is discharged from ports 45 at a relatively high velocity and this discharge is effective to purge the pipe of particles and the like before the spray material is applied. In this connection, it is to be noted that the reaction fluid discharge ports 45 slant outwardly away from the spray ports 44, so that the air discharge tends to carry any particles present on the inner surface of the pipe forcibly away from the area in which the spray material is discharged.

The device is particularly useful for spraying the inner surface of hollow work and, therefore, is frequently employed in what can be considered as a semi-closed environment. Such operating conditions make entry of the spray material into openings in the spray device a distinct danger. On the other hand, the rotor ll must be kept free to turn, even under the low starting torques available from the effect of discharge of the reaction fluid, and positive mechanical seals are therefore undesirable. In this connection, it is to be noted that the annular space 43, com municating with the space between faces 14 and 44 allows a relatively small portion of the air supplied from tube 16 to be discharged from the end of tubular extension 42 toward the location of ports 45. Such discharge of air prevents both the spray material and foreign particles from entering extension 42 and finding their way to the bearing area.

The spray material is delivered from tube 16 to the space between surfaces 25 and 34 at a constant rate which is predetermined, by conventional feed apparatus not shown, for the conditions of operation. Once delivered to the space between surfaces 25 and 34, the spray material is forced outwardly centrifugally, by reason of high speed rotation of the nozzle resulting from discharge of the reaction fluid via ports 45. The spray material is discharged centrifugally via ports 44, rather than by positive pressure, and is atomized primarily as a result of the relatively high escape velocity, rather than by air flow.

Advantageously, the supply of compressed air via tube 16 is commenced before feeding of the spray material via tube 15 is started, and is terminated after feeding of the spray material is stopped. This procedure allows the rotor to come up to working speed before the spray material enters the nozzle member 4, and assures that residual amounts of spray material will be purged from the nozzle member before rotation of the nozzle member ceases.

A particular advantage of the invention lies in its ability to apply thicker, more uniform coatings of relatively viscous, high-solids-content coating materials than has heretofore been possible. Thus, in a single pass of the device through a pipe to be coated, the embodiment of the invention illustrated is capable of applying a uniform coating of relatively viscous resinous material up to 25 or more mils in thickness. The ability of the device to apply such thicker coatings flows in part from the location of ports 44 relative to surfaces 34 and 25. As has been previously described, the spray material, after travelling centrifugally outwardly over surface 34, forms cylindrically on surface 3% From FIG. 5, it will be seen that the ports 44 are not only arranged in a succession of circles centered on the axis of rotation of the nozzle member but are also staggered from circular row to circular row, so that certain ones of the ports in all four circular rows or series lie on a line which extends helically about the axis of rotation. Because of this manner of spacing of the ports, and recognizing that, during use, the nozzle member is both rotating and moving axially relative to the work, it will be clear that the operating parameters can be so selected that each discrete area of the work surface is subjected successively to the spray from spray ports 45 which are in more than one of the circular series of spray ports.

For purposes of economy, it is advantageous to make ports 44 and 45 in the form of straight bores extending angularly through the wall of portion 8 of nozzle member 4. However, those skilled in the art will recognize that the ports can be provided in other ways. While it is advantageous to have ports 44 angularly disposed in the same manner as ports 45, since the ports 44 can then serve as reaction fluid ports before the feed of spray material commences, ports 44 can be arranged radially or in other fashions.

For purposes of simplicity of terminology, the ports 45 are defined as each having a discharge axis extending as a tangent to a circle centered on the axis of rotation for the rotor, even though the discharge axes are also advantageously inclined axially in the manner shown in FIGS. 6 and 7.

Turning now to FIGS. 8l5, it will be seen that this embodiment of the invention comprises a hollow rotor 51, a supporting and fluid supply structure indicated generally at 52, and a rigid assembly 53 of concentric tubes for supplying the driving fluid under pressure and the material to be sprayed, the assembly 53 also serving to manipulate the spray device relative to the work.

Rotor 51 includes an integral nozzle member 54 and a tubular extension 55. Nozzle member 54 is generally cup-shaped, being closed at its tip and having an open, exteriorly threaded end portion 56, the tubular portion between the tip and open end of the nozzle member being of adequate length to provide space for an annular transverse exterior portion 58. Between portion 58 and extension 55, the nozzle member is provided with a trans verse annular outwardly projecting flange 57. As seen in FIGS. 9 and 10, both nozzle member '4 and extension 55 are of circular transverse cross-section. At one end, the extension 55 has internal threads engaged with the external threads at the open end of the nozzle member.

Adjacent flange 57, extension 55 has a first right cylindrical surface 5% of larger diameter. The remaining outer surface 59' of the extension is in the form of a right cylindrical surface of somewhat smaller diameter, as shown.

In an area spaced axially from its internally threaded end, extension 55 includes a portion 6%, of smaller internal diameter, disposed between two portions of larger internal diameter, the latter portions accommodating rotary ball bearings 61 and 63, respectively. In that portion of extension 55 disposed between nozzle member and bearing 61, the tubular wall of the extension is provided with a plurality of generally radially extending, circularly spaced bores 63.

Assembly 53 includes a central tube 65 and an outer tube 66, both exteriorly threaded at their tips. The supporting and fluid supply structure 52 includes a main body 67 and a rigid tubular central member 63 carried thereby. Body 67 has an axial bore 69 which is interiorly threaded at each end. The threaded tip of central tube 65 of assembly 53 is engaged in one threaded end portion of bore 69. Tubular central member 68 has an exteriorly threaded end portion engaged in the other threaded end portion of bore 69. Body 67 has an interiorly threaded cylindrical extension 70, the threads of which are engaged with the threaded tip of outer tube 66. A plurality of longitudinally extending, circularly spaced bores 71, all communicating with the space between tubes 65 and 66, lead through body 67.

At its end opposite assembly 53, body 67 has an outer cylindrical surface portion 72 of reduced diameter terminated by shoulder 73. A tubular sleeve 74 slidably embraces surface portion 72 of body 67, one end 75 of the sleeve being engaged with shoulder 73. Sleeve 74 serves to mount a right cylindrical, thin-walled tubular confining member 76 which projects from sleeve 74 forwardly toward flange 57 of nozzle member 54 and, therefore, surrounds the tubular extension 55. Sleeve 74 has a main cylindrical outer surface portion which is slidably engaged by the inner surface of member 7 6 and which is terminated by the shoulder, at 77, engaged with the corresponding end of member 76.

The outer surface 72 of body 67, and the inner surface of sleeve 74, are provided with matching transverse annular grooves, as will be clear by comparison of FIGS. 8 and 11, which accommodate a snap-type retaining spring 78. Similarly, the outer surface of sleeve 74 and the corresponding inner surface portion of member 76 are provided with matching transverse annular grooves which coact to accommodate a retaining spring 79.

Member 76 projects from sleeve 74 adequately to extend well beyond the location of bores 63. The inner diameter of member 76 is only slightly greater than the outer diameter of outer surface portion 59 of member 55. Accordingly, member 76 cooperates with the outer surface portions 59 and 59' of member 55 to define annular spaces 80 and 80. Immediately adjacent the corresponding end of main body 67, tubular central member 63 is provided with outwardly projecting transverse annular deflecting flange 81. Flange 81 has an outer diameter only slightly smaller than the diameter of surface portion 59' of extension 55. The flange tapers conically toward the juncture between member 68 and body 67. As will be clear from FIG. 8, all of bores 71 open toward the tapered surface of flange 81. Accordingly, fluid supplied from the space between tubes 65 and 66 and travelling via bores 71 passes outwardly about flange 81 first into space 80. Of this fluid, the major portion is conveyed inwardly,

to the interior of member 55, by bores 63. A small proportion of the fluid is, however, carried by the annular space 80 and discharged toward flange 57 from the open tip of member 76.

On the side of flange 81 opposite body 67, central tubular member 68 has a right cylindrical outer surface which, as shown, is directly engaged by the inner races of the ball bearings 61 and 62. The assembly of bearings 61 and 62, and tubular ex ension 55, is retained on member 68 by a suitable snap-type retaining element 82, engaged in a matching groove in member 68, as shown in The length of member 63 is such that the exteriorly threaded tip portion '53 thereof is located within the tubular portion of nozzle member 54-. A discharge tip member 34, provided with an interiorly threaded skirt, is mounted on tip portion 83 of member 68. Discharge member 84 has a flat, annular, transversely extending face 35 which is directed toward and parallel with the flat face 86 provided by the closed end of nozzle member 54.

The tubular portion of nozzle member 54 has a cylindrical inner wall 87 which extends for the greater part of the length of this portion. With the outer surfaces of the adjacent portion of member 63 and of discharge member 84-, surface 37 defines an annular space 38. In the area surrounding the free end of discharge member 84, the inner diameter of the tubular portion of nozzle member is increased, providing a cylindrical inner surface 39 which is somewhat larger in diameter than is surface 87, surfaces 87 and 89 being joined by a frustoconical shoulder 96 which tapers away from the closed end of the nozzle member. The axial length of surface portion 89 is materially greater than the axial spacing between faces 35 and 36, so that a portion of surface 89 overlaps the end portion of discharge member 84. Within the area defined by surface 39, the tubular wall of nozzle member 54 is provided with a plurality of outwardly directed, angularly disposed discharge ports 91. As will be clear from FIG. 12, the ports Q1 are arranged in groups with each group extending helically relative to the outer cylindrical surface of portion 58 of the nozzle member.

Referring to FIGS. 8 and 12, it will be understood that ports 91 open not only directly toward the space between faces 85 and 86, but also toward the outer end portion of discharge member 84. Thus, the ports are distributed both circularly and axially over the entire area of the nozzle member defined by surface 89.

All of discharge ports 91 are similarly angularly disposed so as to extend tangent to a circle centered on the central axis of member 68, as will be clear from FIG. 9. As indicated in FIG. 8, all of discharge ports 91 also are inclined forwardly and outwardly of the nozzle member.

Operation of this embodiment of the invention is generally similar to operation of the embodiment hercinbefore described with reference to FlGS. 1-7, save that both the driving fluid, supplied via the space between tubes and 66, and the material to be sprayed, supplied via tube 65 and member 68, are discharged via ports 91. The driving fluid, normally air under pressure, is supplied forwardly via borcs 71, space bores 63, and space 88. The material to be sprayed is supplied concurrently, under pressure, via bore 69, the bore of member 68, discharge member 84, and the space between faces 35 and 86. Escape of the driving fluid through ports 91 causes rotation of rotor 51 on bearings 61 and 62. Such rotation causes the material to be sprayed to be discharged centrifugaliy via the ports 91 and atomized as it escapes from the ports. Since some of the driving fluid is discharged forwardly from the tip of member '76 and, therefore, about flange 57, it is impossible for sprayed material to find its way to the region of bearings 61 and 62.

Since discharge ports 91 are distributed over the axial distance between face 86 and shoulder 90, the device Of this embodiment of the invention is selfmmpensating in the same general fashion as hereinbefore described with reference to the embodiment illustrated in FIGS. 1-7. Thus, referring to FIG. 8, it will be obvious that the material to be sprayed, discharging from the central bore of member 84, spreads centrifugally outwardly over the flat face 86 and then over the annular surface 89 through which ports 91 open. Depending upon viscosity of the spray material and the pressure and rate at which it is supplied, the spray material may escape via only the ones of ports 91 nearest surface 86', or may be discharged at progressively lower rates through those ports spaced in succession away from surface 86.

The embodiment of the invention illustrated in FIGS. 812 is particularly advantageous when the material to be sprayed is of relatively lower viscosity. In this embodiment, it is to be understood that the driving fluid, such as air under pressure, and the spray material both escape via ports 91, no separate driving ports being employed. Passage of the driving fluid forwardly through annular space 83 of course aids in keeping the spray ma terial away from the region of bearings 61 and 62.

Where the device is to be employed for spraying more viscous materials, the nozzle member 54- and discharge member 84 can be modified in the fashion seen in FIG. 13. Here, the nozzle member is provided with a transverse annular interior shoulder 92 spaced from shoulder 90 and facing toward the open end of the nozzle member. Discharge member 84 is provided, at its end nearest the open end of the nozzle member, with a transverse, annular, outwardly extending flange 93 of such diameter that the periphery of the flange lies in close proximity to the cylindrical surface 8'7 of the tubular portion of the nozzle member immediately adjacent to shoulder 92. Flange 93 has an inwandly and forwardly tapering front face disposed in close proximity to shoulder 92. Accordingly, flange 93 serves to substantially seal the space between member 84 and the tubular portion of the nozzle in an area located between discharge ports 91 and flange 57.

In this modified form of the nozzle member, a plurality of driving ports 94 are provided immediately adjacent to flange 57 and on the side of flange 57 nearest the closed end of the nozzle member. Driving fluid under pressure passes via bores 63 into the open end of the nozzle member and is discharged outwardly via the driving ports 94. Because of the substantial sealing effect of flange 93, only a small proportion of the driving fluid is allowed to pass forwardly to the are-a occupied by spray ports 91. Driving ports 94 are, of course, angularly disposed so that each driving port extends as a tangent to a circle centered on the longitudinal axis of central member 68. The driving ports 94 are also inclined outwardly away from the location of spray ports 91.

FIGS. 14 and 15 illustrate typical arrangements for the discharge ports 91 and the driving ports 94, respec* tively.

In assembling the embodiment of the invention illustrated in FIGS. 8-12, body 67 is first applied to the concentric tubes 65 and 66. Sleeve '74 and confining member 76 are then mounted on body 67 with the aid of the retaining springs 78 and 79. Member 55, with its bearings 61 and 62, is then placed on central member 68 and secured in its operative position by the snap-retainer d2. Normally, discharge member 84 will already have been applied to member 68. The assembly is now completed by attaching nozzle member 54 to the internally threaded end of tubular member 55.

Though particularly advantageous embodiments of the invention have been chosen for illustration, it will be understood that various changes and modifications can be made therein Without departing from the scope of the invention defined in the appended claims. Thus, in particular, it is to be understood that the invention is not limited to the specific angular disposition and particular spaced orientation of the discharge ports, nor to specific structural features and modes of use referred to.

What is claimed is: 1. In a rotary spray device of the type described, the combination of a hollow rotor having a closed end, an open end and a tubular portion therebetvveen; a rotor supporting structure comprising a projection of smaller transverse dimension than said tubular portion of said rotor, and first duct means extending through said projection, said projection terminating in a discharge tip through which material to be sprayed, supplied under pressure via said first duct means, is discharged; rotary anti-friction bearing means mounting said rotor on said supporting structure with said tubular portion of said rotor surrounding and spaced outwardly from said projection,

said closed end of said rotor being disposed adjacent to said discharge tip of said projection, said tubular portion of said rotor being provided with a plurality of outwardly opening ports spaced circumferentially about said rotor, at least some of said ports being located in at least approximately the same axial position as is said discharge tip to receive and discharge the material to be sprayed, at least some of said ports being angularly disposed in such fashion that their axes of discharge each extend as a tangent to a circle centered on the axis of rotation of said rotor; and second duct means for supplying fluid under pressure to the annular space between said projection and said rotor for discharge via at least some of said ports to drive said rotor. 2. A rotary spray device in accordance with claim 1 and wherein said ports include a plurality of spray discharge ports all located in the region of said discharge tip, said spray discharge ports being arranged in a plurality of circular series spaced axially of said rotor, some of said spray discharge ports being spaced from said discharge tip toward the open end of said rotor. 3. A rotary spray device in accordance with claim 1 and wherein said discharge tip includes a transverse end face and is provided with a discharge orifice opening through said face, said closed end of said rotor presents a transverse face opening toward and spaced adjacent to said transverse phase of said discharge tip, and said transverse faces define a space into which the material to be sprayed is discharged via said orifice and through which such material flows radially outwardly to the region of said ports as said rotor is rotated. 4. A rotary spray device in accordance with claim 3 and wherein said ports include a plurality of spray discharge ports 60 spaced over a material part of the length of said tubular portion of said rotor, some of said spray discharge ports communicating directly with the space between said transverse faces, others of said spray discharge ports being spaced axially [from said transverse end face of said discharge tip toward the open end of said rotor and communicating with the annular space between said tubular portion and said projection. 5. A rotary spray device in accordance with claim 1 and wherein at least a portion of the inner wall of said tubular portion of said rotor tapers inwardly and away from said closed end of said rotor. 6. A rotary spray device in accordance with claim 1 75 and further comprising a tubular member surrounding said rotor and spaced outwardly therefrom,

said tubular member having an open tip directed toward the location of said ports; and means placing the space between said tubular member and said rotor in communication with said second duct means. 7. In a rotary spray device of the type described, the combination of a hollow rotor having a closed end, an open end and a tubular portion therebetween; a rotor supporting structure comprising a projection of smaller transverse dimension than said tubular portion of said rotor, and first duct means extending through said projection, said projection terminating in a discharge tip through which fluid material to be sprayed, supplied under pressure via said first duct means, is discharged; rotary anti-friction bearing means mounting said rotor on said supporting structure with said tubular portion of said rotor surrounding and spaced outwardly from said projection,

said closed end of said rotor being disposed adjacent to said discharge tip of said projection, said tubular portion of said rotor being provided with a plurality of outwardly opening spray discharge ports spaced generally circumferentially about said rotor and located in at least approximately the same axial position as is said discharge tip, said tubular portion of said rotor also being provided with a plurality of reaction fluid discharge ports spaced generally circumferentially about said rotor in a location spaced from said spray discharge ports toward said open end of the rotor, said reaction fluid discharge ports being angularly disposed in such fashion that the discharge axis for each of said ports extends as a tangent to a circle centered on the axis of rotation of said rotor, said spray discharge ports and said reaction fluid discharge ports communicating with the interior of said hollow rotor; and second duct means for supplying reaction fluid under pressure to the annular space between said projection and said rotor, supply of fluid under pressure, via said second duct means, causing the reaction fluid to discharge via said reaction fluid discharge ports with such discharge causing said rotor to rotate at high speed relative to said supporting structure, such rotation causing the fluid material to be sprayed to be centrifugally discharged outwardly via said spray discharge ports. 8. A rotary spray device in accordance with claim 7 and wherein said spray discharge ports are angularly disposed similarly to said reaction fluid discharge ports. 9. A rotary spray device in accordance with claim 7 and wherein said reaction fluid discharge ports are inclined outwardly away from the region of said spray discharge ports. 10. A rotary spray device in accordance with claim 7 and further comprising annular partition means located in the annular space between said tubular portion of said rotor and said projection, said partition means being disposed between said spray discharge ports and said reaction fluid discharge ports. 11. In a rotary spray device of the type described, the combination of elongfied tubular means having at one end a discharge tip and adapted for connection at its other end to 12 conduit means for supplying fluid spray material under pressure to be discharged via said tip; a hollow rotor having a closed end and a tubular portion projecting therefrom,

said rotor being disposed with its closed end adjacent to but spaced from said discharge tip and said tubular portion surrounding said tubular means and spaced outwardly therefrom; anti-friction bearing means operatively arranged between said tubular means and said rotor in a location spaced axially from the closed end of said rotor, said bearing means mounting said rotor on said tubular means for rotation about the longitudinal axis of said tubular portion of said rotor, said tubular portion of said rotor being provided with a plurality of discharge ports, at least some of said ports being located at least generally in the axial region of said discharge tip, at least some of said ports being angularly disposed in such fashion as to be each tangent to a circle centered on the axis of rotation of said rotor; and means carricd by said elongated tubular means and defining duct means communicating with the space between said tubular means and said tubular portion of said rotor for supplying reaction fluid under pressure thereto. 12. A rotary spray device in accordance with claim 11 and wherein said ports include a plurality of spray discharge ports, at least some of which open into the space between said closed end of said rotor and said discharge tip, and a plurality of reaction fluid discharge ports, said reaction fluid discharge ports being spaced axially from said spray discharge ports on the side thereof opposite said closed end of said rotor. 13. A rotary spray device in accordance with claim 11 and wherein said rotor has a cylindrical outer surface at the end thereof opposite said closed end, the spray device further comprising a tubular member spaced outwardly from said cylindrical surface and having an open tip directed toward said ports, said duct means communicating with the annular space between said cylindrical surface and said tubular member. 14. In a rotary spray device, the combination of a hol- 10w rotor having a closed end and a tubular portion;

a central member disposed coaxially within said tubular portion of said rotor and having an axial bore, and a tip disposed adjacent to but spaced from me closed end of said rotor, said bore opening through said tip for discharge of fluid spray material into the space between said closed end of said rotor and said tip; anti-friction rotary bearing means mounting said rotor for rotation about the axis of said tubular portion,

said rotor being provided with a plurality of outwardly opening spray ports communicating with the space between said closed end of said rotor and said tip of said central member, said rotor also being provided with a plurality of augularly disposed reaction fluid discharge ports communicating with the space between the tubular portion of said rotor and said central member in a location spaced axially from said tip, said reaction fluid discharge ports being arranged to discharge fluid outwardly along axes which are each tangent to a circle centered on the axis of rotation of said rotor; and means for supplying reaction fluid under pressure to the space between said tubular portion of said rotor .and said central member.

13 15 In a rotary spray device, the combination of a hollow rotor having a closed end, an open end and a tubular portion therebetween; a central tubular structure disposed coaxially with respect to said tubular portion of said rotor and having a tip located within said rotor and adjacent to said closed end, said tip having a transverse end face, said closed end of said rotor presenting a transverse face directed toward the end face of said tip, the bore of said tubular structure opening through said end face of said tip for supply of fluid spray material to the space between said transverse faces; anti-friction rotary bearing means mounting said rotor for rotation about the longitudinal axis of said central tubular structure, said tubular portion of said rotor being concentric with said axis,

said tubular portion of said rotor being provided with a plurality of ports spaced both circumferentially and axially of said tubular portion, some of said ports opening directly into the space between said transverse faces, others of said ports opening directly into the annular space between said tubular portion of said rotor and said central tubular structure in an area adjacent said transverse end face of said tip; and means for supplying reaction fluid under pressure to the interior of said rotor. 16. A rotary spray device in accordance with claim 15 and further comprising two concentric fluid supply tubes; a body member having an axial bore,

the inner one of said supply tubes being connected to said body member in communication with said axial bore,

the outer one of said supply tubes also being connected to said body member,

said body member having at least one duct communicating with the space between said inner and outer tubes; and

a tubular member mounted on said body member and projecting toward said rotor,

said tubular member having an open end portion surrounding said tubular portion of said rotor and spaced outwardly therefrom, said open end portion terminating short of said ports,

the annular space between said rotor and said tubular member communicating both with said at least one duct of said body member and the annular space between said rotor and said central tubular means.

References Cited in the file of this patent UNITED STATES PATENTS 1,725,012 Meurer Aug. 20, 1929 1,803,425 Cunningham May 5, 1931 2,336,293 Pletcher Dec. 7, 1943 2,694,022 Schreiner Nov. 9, 1954 2,735,794 Pietcher Feb. 21, 1956 2,954,038 Girard Sept. 27, 1960 2,993,650 Badberg July 25, 1961 3,000,575 Hruby Sept. 19, 1961 3,029,027 Gray Apr. 10, 1962 3,034,729 Gray May 15, 1962

Claims

1. IN A ROTARY SPRAY DEVICE OF THE TYPE DESCRIBED, THE COMBINATION OF A HOLLOW ROTOR HAVING A CLOSED END, AN OPEN END AND A TUBULAR PORTION THEREBETWEEN; A ROTOR SUPPORTING STRUCTURE COMPRISING A PROJECTION OF SMALLER TRANSVERSE DIMENSION THAN SAID TUBULAR PORTION OF SAID ROTOR, AND FIRST DUCT MEANS EXTENDING THROUGH SAID PROJECTION, SAID PROJECTION TERMINATING IN A DISCHARGE TIP THROUGH WHICH MATERIAL TO BE SPRAYED, SUPPLIED UNDER PRESSURE VIA SAID FIRST DUCT MEANS, IS DISCHARGED; ROTARY ANTI-FRICTION BEARING MEANS MOUNTING SAID ROTOR ON SAID SUPPORTING STRUCTURE WITH SAID TUBULAR PORTION OF SAID ROTOR SURROUNDING AND SPACED OUTWARDLY FROM SAID PROJECTION, SAID CLOSED END OF SAID ROTOR BEING DISPOSED ADJACENT TO SAID DISCHARGE TIP OF SAID PROJECTION, SAID TUBULAR PORTION OF SAID ROTOR BEING PROVIDED WITH A PLURALITY OF OUTWARDLY OPENING PORTS SPACED CIRCUMFERENTIALLY ABOUT SAID ROTOR, AT LEAST SOME OF SAID PORTS BEING LOCATED IN AT LEAST APPROXIMATELY THE SAME AXIAL POSITION AS IS SAID DISCHARGE TIP TO RECEIVE AND DISCHARGE THE MATERIAL TO BE SPRAYED, AT LEAST SOME OF SAID PORTS BEING ANGULARLY DISPOSED IN SUCH FASHION THAT THEIR AXES OF DISCHARGE EACH EXTEND AS A TANGENT TO A CIRCLE CENTERED ON THE AXIS OF ROTATION OF SAID ROTOR; AND SECOND DUCT MEANS FOR SUPPLYING FLUID UNDER PRESSURE TO THE ANNULAR SPACE BETWEEN SAID PROJECTION AND SAID ROTOR FOR DISCHARGE VIA AT LEAST SOME OF SAID PORTS TO DRIVE SAID ROTOR.