US3074650A

US3074650A - Spraying mechanism

Info

Publication number: US3074650A
Application number: US795650A
Authority: US
Inventors: Joseph S Kanarek
Original assignee: Ziff Davis Publishing Co
Current assignee: Ziff Davis Publishing Co
Priority date: 1959-02-26
Filing date: 1959-02-26
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22

Description

Jan. 22, 1963 J. s. KANAREK 3,074,650

SPRAYING MECHANISM Filed Feb. 26, 1959 2 Sheets-Sheet 1 United States Patent 3,074,650 SPRAYING MECHANISM Joseph S. Kanarek, Lombard, Ill., assignor, by mesue assignments, to Ziif-Davis Publishing Company, New York, N .Y., a corporation of Delaware Filed Feb. 26, 1959, Ser. No. 795,650 1 Claim. (Cl. 239-215) This invention relates to a spraying mechanism and more particularly to a rotary mechanism adapted to attenuate liquids, such as paint and the like, and to discharge the attenuated liquid therefrom.

Spraying mechanisms embodying the present invention are of general utility and may have any desired form and shape. An illustrative embodiment of the present invention is in the form of a spray gun having a pistollike grip or handle. The spray gun form of the invention is described below in conjunction with the accompanying drawings as an illustrative embodiment of the invention. Also, the spray gun will be described with reference to its use for spraying paint, although it may be used with any suitable liquid.

The spray gun has a lower chamber or can for holding the paint. A conveyor in the form of a feed screw or screw conveyor feeds the paint upwardly from the lower chamber to an upper chamber and an attenuator, which in this embodiment of the invention is a smooth surfaced inverted cone, is rotatably mounted in an upper chamber and receives the paint fed upwardly by the screw conveyor. A motor mounted in the mechanism rotates the screw conveyor for feeding paint and rotates the inverted cone to attenuate the paint. An adjustable shield controls the outlet through which the attenuated paint is discharged. I

The inverted cone attenuator has a substantially flat outer peripheral edge portion" across which attenuated and filmed paint is discharged as a finely filmed spray substantially in the fiat plane of theflouter edge portion of r the attenuator.

distanceabove the open top of the attenuator to cover the inverted cone attenuator to prevent excess discharged paint expelled from the spraying mechanism as a whole, from rebounding or otherwise re-entering the attenuator from the;top. This prevents such excess paint from disturbing the filming-out and attenuating action of the attenuator. By this means a smooth and uniform spray is obtained without interference from excess discharge from the attenuator and Without spattering or other irregularitie's in the spray pattern. 7

The excess paint discharged from the attenuator is redirected and fed back to the lower chamber or paint can through communication openings from the upper chamber, for reuse.

In addition to the valve assembly on the feed tube, the magnitude of the discharge from the spray gun, and the width of the spray pattern are controlled by a shield arrangement on the spray gun. An inner shield fixed to the top of the upper chamber has a skirt depending below the space between the open top of the inverted cone and the flat disk. A portion of the skirt, however, is cut away to provide part of a discharge outlet. An outer shield or gate is rotatably mounted between the inner shield and the top of the upper chamber, and has a depending skirt substantially of the same size and shape as the skirt of ice the inner shield. A lever fixed to the outer shield projects outwardly through a slot in the housing and is accessible for manually rotating the outer shield to vary the length of the discharge outlet formed by the portions of the openings in the two shields in registration with each other.

The maximum length of the discharge outlet is limited to the size of the openings in the skirts of the shields, which, in this embodiment is about one-fourth the circumference of the skirts, respectively. Thus, in this embodiment of the invention, approximately seventy-five percent of the paint passing across the outer edge of the inverted cone strikes the inner surface of the inner shield, and a small additional portion of the paint may strike the inner surface of the portion of the outer skirt which may overlap the opening in the inner skirt such as when the openings in the two skirts are not in complete registration.

The skirts of the shields in addition to controlling the magnitude of the discharge from the spray gun, also are effective to redirect the excess paint issuing from the attenuator, toward the bottom of the upper chamber for return through the communication openings to the can. For this purpose at least the upper portions of the skirts are formed as substantially 45 cones and are radially aligned with the outer edge portion of the attenuator so that excess paint issuing from the attenuator will strike the conical surfaces and be redirected as described.

Some of the excess paint may find its way onto the top and edge of the cover plate or disk. To prevent this portion of the excess from interferring with the spray pattern, the inner shield is provided with a doctoring blade having an edge closely adjacent the top surface and to the edge of the cover plate. The plate rotates with the inverted cone, and the doctoring blade scrapes the paint from the top of the plate and directs it to another doctoring blade which extends below the upper edge of the inverted cone and removes excess paint from the edges of the attenuator and the disk cover plate. The paint removed in this manner then flows back into the lower chamber along with the rest of the excess paint.

The structure by means of which the above-mentioned and other advantages of the invention are attained will be described in the following specification, taken in conjunction with the accompanying drawings forming a part of this specification, showing a preferred illustrative embodiment of the invention, in which like reference numerals refer to likeparts and in which:

FIGURE 1 is a front elevational view of a spray gun embodying the invention;

FIGURE 2 is a side elevational view of the spray gun;

FIGURE 3 is a fragmentary vertical view, partly in elevation and partly in section, showing the interior construction of the spray gun;

FIGURE 4 is a fragmentary vertical sectional view, showing the screw conveyor for feeding the paint into the inverted cone; and

FIGURE 5 is a detail perspective view of the inverted cone.

Referring to the drawings, the reference numeral 2 indicates a motor housing in which is mounted a motor (not shown) having a drive shaft 3 (FIGURE 4) depending therefrom. A hollow handle 4, fixed to housing 2 in any suitable manner forms a conduit for electrical wiring 5 for connecting the motor to an electric current source. A switch (not shown) is mounted on the handle for controlling operation of the motor. A barrel 6 having a cylindrical wall 7 is secured to the underside of housing 2 by a plurality of screws 8 (FIGURE 3). Barrel 6 has a lower transverse wall 9 provided with a plurality of liquid return apertures 10; and a skirt 11 depends from. thecylindrical wall 7 below the transverse .wall 9.

A container or can engaging external thread 12 extends around the external circumferential face of the skirt 11.

Barrel 6 has an open top and fits against the bottom wall 2' of housing 2 to form an upper chamber '13.

The upper end of a central tubular hub 14 fixed to transverse 'wall 9 extends into chamber 13, and its lower end extends below the lower edge of the cylindrical skirt 11 on 'the barrel 6. An integral arm 15 extending upwardly at a slight angle from hub 14 to cylindrical wall 7 is provided with an axial recess in threaded to receive a valve control screw 17 having a conical end 18. An aperture 19 extends through the lower wall of arm 15 adjacent to the inner end of recess 16.

The inner surface of hub 14 is threaded to receive a tubular sleeve 20 which extends below the lower edge of hub 14, and a lock nut 21 is threaded on the lower end of the sleeve to hold the hub and sleeve against accidental separation. The upper end of sleeve 26 is recessed on its outer surface, as indicated at 22, and the upper end of hub 14 is recessed on its inner surface, as indicated at 23, to form an annular space 24 between the upper end of sleeve 2% and the upper end of hub 14. An attenuator in the form of an inverted cone 25 disposed within the chamber formed by the barrel 6 and the transverse wall 2 of the housing 2, is provided with a depending cylindrical flange 26 fitting loosely in space 24. A washer 26' or other form of seal is provided between the upper 22d of the sleeve 20' and the lower end of the attenuator A vertical boss 27 extending upwardly from the apex region of the cone 25 is provided with an axial bore 28 counterbored from the lower end, as indicated at .29, to form a shoulder 36. The outer surface of boss 27 is provided with a plurality of external reinforcing ribs 31 and the lower end of boss 27 is provided with a plurality of apertures 32 which terminate substantially flush with annular shoulder 30.

The lower end or" drive shaft 3 has an axial bore 33 threaded to receive a screw 34 rigidly secured to the upper end of a screw conveyor 35. Screw 34 has an annular flange 36 abutting the upper end of screw conveyor 35. Flange 36 fits within counterbored portion 29 of boss 27 and engages shoulder to support inverted cone 25. If desired, the inverted cone may be supported on the upper endof sleeve 20 or on the bottom of space 24.

Screw may be of any suitable material, but is preferably made of nylon which is inert and noncontaminating to liquids to be conveyed thereby. The screw 35 extends to a point spaced a short distance above the bottom of a can 37 or other receptacle which comprises the lower chamber of the spray gun. Can 37 is provided with a wide month which is threaded, as indicated at 38, to engage thread 12 of the skirt 11 on the barrel 6 so that it may be easily attached to and removed from the spray .gun, for cleaning or filling. The can has no opening except its mouth, and completely encloses the lower portion of the spray gun.

A tube 3% is drive fitted into the lower end of sleeve 20 and cooperates therewith to provide an open ended housing for screw 35. The lower end of tube 39 extends a short distance below the bottom of screw 35. A split, metal clamp 40 extends around tube 39 above its lower end. The clamp is held against the tube with sufiicient friction to prevent relative movement therebetween. Clamp 40 has an integral extension 41 extending downwardly and outwardly relative to tube 39. Extension 41 is bent, as indicated at 42, to provide a resilient, flat, valve plate 43 extending across the open bottom of tube 39. A rigid, valve operating rod 44 has one end secured to the free end of the plate 43 and the other end 45 of the rod 44 projects through aperture 19 into tube 15.

As the screw 17 is threaded into tube 15 the conical end 18 of the screw engages the end 45 of rod 44 and forces the rod downwardly, thereby moving the resilient valve plate 43 away from the bottom f tube 39, The

.4 angle of extension 41 enables the resilience of the metal of which plate 43 is formed to move the plate toward the bottom of tube 39 as screw 17 is threaded outwardly relative to tube 15. Thus, the plate 43 acts as a flap valve for the open end of tube 39, and the distance between plate 43 and the bottom of tube 39 controls the amount of paint that is permitted to flow from the can 37 into the tube 39.

Boss 27 extends slightly above the plane of the upper end of inverted cone 25, and a disk-shaped cover plate 45, apertured tofit around drive shaft 3, is seated on the top of the boss. Plate 46 is held in position by a sleeve 47 and a plurality of washers 48 which are mounted on the drive shaft above the disk. The diameter of the plate 46 may be substantially equal to or slightly greater than the diameter of the upper end of inverted cone 25 and is spaced therefrom to provide a continuous opening 49 between the upper end of the inverted cone and the disk throughout the circumference thereof, for flow of attenuated paint across the llat outer edge portion 25' of the attenuator.

An inner shield 50' is rigidly secured to the bottom of motor housing'2 by screws 51 and has an annular skirt 52 depending into upper chamber 13 below opening 49. An outer shield 53 is rotatably mounted between inner shield 56 and the bottom of motor housing 2. Shield 53 has a depending skirt 54 of approximately the same size and shape as skirt 52. A finger operated lever 55 secured to outer shield 53 "projects through a slot 56 in housing 2. Lever 55 may be manually manipulated to rotate outer shield 53.

Each of

skirts

52 and 54 has an opening which in this embodiment of the invention is approximately one-fourth of the circumference of the skirts to provide openings 57 and 58, respectively. When lever 55 is positioned to make opening 58 coincide with opening 57, the discharge outlet, which comprises the portions of openings 57 and 58 that are in registration with each other, has a length equal to about one-fourth of the circumference of either skirt, which is the maximum length of the discharge outlet. As lever 55 is moved from said position, the length of the discharge outlet is gradually reduced by movement of lever 55 in the same direction, until the. discharge outlet is closed by the continued rotation of outer shield 53 until opening 58 is completely out of registration with opening 57.

The

skirts

52 and 54 of the

shields

50 and 53, in addition to controlling the magnitude of the discharge from the spray gun, also are effective to redirect the excess paint issuing from the attenuator, toward the bottom 2' of the upper chamber 13 for return through the communication openings 10 to the can 37. For this purpose at least the upper portions 52 and 54' of the

skirts

52 and 54 are formed as substantially 45 cones and are radially aligned with the outer edge portion 25' of the attenu'ator 25 so that excess paint issuing from the attenuator will strike the

conical surfaces

52 and 54 and be redirected as described.

In the operation of the spray gun the screw 35 is rotated counter-clockwise, as viewed in FIGURE 4. This direction of rotation of the screw causes the groove 59 to move the paint in the groove upwardly until it reaches the top of the screw. The paint then flows through openings 32 and is attenuated, filmed-out and spreads outwardly on the surface of the rotating inverted cone. The paint moves upwardly on the surface of the cone and is filmedout and increasingly attenuated until it moves outwardly across or over the flat peripheral edge region 25' of the cone attenuator 25. The distribution of the paint around the circumference of attenuator 25 is substantially uniform, and the paint is centrifugally sprayed across the edge portion 25 as a finely filmed spray.

The paint that impinges on the conical portions 52' and 54' of the

shields

50 and 53 is directed thereby to flow through apertures 10 into the lower chamber. Inner shield 50 is provided with

doctoring blades

60 and 61 that have edges arranged radially and axially of the plate 46 so close to its upper surface and edge, respectively, that they scrape excess paint therefrom as the plate is rotated. Blade 60 terminates adjacent to blade 61 that extends downwardly past the outer upper edges of the plate 46 and the inverted cone 25 to remove excess paint therefrom and guide the paint downwardly into upper chamber 13, from which it flows through apertures along with the excess paint from the inner surface of the skirts. Paint passing through apertures 10 falls directly into the lower chamber from which it is again fed by screw conveyor 35.

The size of the pattern of paint sprayed may be regulated by adjusting the length of the discharge outlet. This is done by rotating outer shield 53 by means of lever 55. The amount of paint sprayed is afiected by two factors, namely the distance between plate 43 and the bottom of tube 39, and by the speed of the motor. Paint may be sprayed from the gun continuously until the lower chamher is substantially empty, because the paint from the lower chamber will be fed upwardly into inverted cone 25 as long as there is enough paint in the lower chamber to be engaged by screw 35.

Although I have described a preferred embodiment of the invention in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details may be modified or changed without departing from the spirit or scope of the invention. Accordingly, I do not desire to be re stricted to the exact construction described.

I claim:

In a spraying mechanism, a lower chamber for containing a liquid to be dispensed, an upper chamber having a discharge outlet, a tube extending from said upper chamher to said lower chamber, a rotatably mounted screw conveyor extending through said tube to carry liquid from said lower chamber to said upper chamber, a resilient cover plate secured by a spring extension thereof and positioned against the open lower end of said tube to regulate the flow of liquid into said tube, a rod secured to said cover, and means accessible from outside said lower chamber and engageable with said rod for moving said cover extension away from the lower end of said tube, the resiliency of said cover moving it toward the lower end of said tube when pressure against said rod is released.

References Cited in the file of this patent UNITED STATES PATENTS 2,023,710 St. Onge Dec. 10, 1935 2,064,125 Norris Dec. 15, 1936 2,086,921 Norris July 13, 1937 2,749,179 Almquist June 15, 1956 2,888,206 Waldrum May 26, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,074,650 January 22, 1963 Joseph S. Kanarek It is hereby certified that error appears in the above numbered patent requiring correction and that th e said Letters Patent should read as corrected below.

Column 6, line- 15', strike out "extension"; line 16, after "cover" insert extension Signed and sealed this 20th day of August 1963.

(SEAL) lttest:

RNEST W. SWIDER xttesting Officer DAVID L. LADD Commissioner of Patents