US2064125A - Method and apparatus for spraying - Google Patents

Description

De c.- 15, 1936.

i ri J'W '12 a [J FiQTE- o Q /9 1a 22 I m 3/ 21 M W T Patented Dec. 15, 1936 METHOD AND APPARATUS FOR SPRAYING Edward 0. Norris, Port Chester, N-. Y., assignor to The Norris Painting Machinery Corporation,

Inc., New York, N Y.,

York

a corporation of New Application October 19, 1931, Serial No. 569,569 Renewed March 17, 1934 16 Claims.

This invention relates to a method and device for spraying liquid and more particularly to a portable paint sprayer. I

In general, it is an object of this invention to provide a device of the character described,

which will eficiently perform the purpose for which it is'intended, which is simple and economical of construction, which can be expeditiously, conveniently and safely manipulated and which isreadily manufactured and assembled.

Another object of this invention is to provide an apparatus for spraying liquid wherein the liquid is preheated with heat derived from excess heat frictionally and electrically arising in the motivating elements.

Another object is to provide liquid spraying apparatus wherein the motivating elements are cooled by the liquid, which is to be sprayed.

' Another object is to provide a centrifugal distributor for liquid spraying apparatus, which is provided with teeth so designed that successive films are cast off having a dimension substantially parallel with the axis of rotation.

Another object is to provide a centrifugal distributor for liquid spraying apparatus adapted to set up successive films having a dimension substantially parallel to the axis of rotation and l provided with rotating slots parallel to said axis for atomizing and further distributing said films. Another object of the invention is to provide a screw feed for a centrifugal spraying apparatus wherein the screw has multiple threads at its delivery end, a portion of the screw feed is unthreaded, and the pitch and/or size of the thread at the pick-up end of said feed is greater than at the end which delivers the material to the centrifugal elements.-

/ Another object of the invention is to provide centrifugal spraying apparatus having a reservoir which is so situated that it may supply material by gravity for substantially all angles of the rotating axis except those approaching the horizontal which is nevertheless not immediately adjacent to the pick-up end of the rotating parts. Other objects of the invention will'in part be obvious and will in part appear hereinafter.

This application is a continuation in part of my copending applications Serial No. 479,900, filed st-tptemtei s, 1930, Serial No. 530,551, filed April 16, 1931, and Serial No. 544,360, filed June 15, 1931.

The invention accordingly comprises the several steps and the relation and order of one or 5 more of such steps with respect to each of the others, and the apparatus embodying features of construction, combinationsof elements and arrangement of parts which are adaptedto effect such" steps, all as exemplifiedjin the following detailed disclosure, and the scope of the 'applica- 5 tion of which will be indicated iri'the claims.

For a fuller understanding. of the nature and objects of the. invention referenceshould behad to the following detailed description taken in connection with the accompanying drawing, in 10 which:

Fig. 1 is a view partly in section and with certain parts cut away of one form of a spraying device embodying the invention; and

Fig. 2 is a perspective view with certain parts 15 cut away of a detail of the device shown in Fig. 1.

In portable spraying devices'it is of importance that the paint, varnish or other liquid which is to spread should be thoroughly beaten. and

.whipped up so that. all portions, no matter how 20 minute, may be alike and that homogeneity may be attained. With a liquid of uniform composition throughout a finished surface is obtainable which it is impossible to secure otherwise. The present invention contemplates-a device wherein 25 the liquid is centrifugally given a, high speed by passing it over revolving teeth. The shape of the teeth gives the annular overflow an axial dimension. Further break-up is secured by smashing the liquid, as it comes from the various 30 teeth, against and through rotating slots.

It is also important from the standpoint of spread that the viscosity and surface tension of applied drops be relatively low.v The hereinafter describeddevice allows part 'of the liquid 35 coming from the distributor element to pick up heat from the motor and then be returned to the main supply line. As 18,000 revolutions ,per minute are not unusual for portable tools of this type, it will be seen how' valuable this feature is 40 for the motor.

Furthermore. it is of importance that a screw feed should add no-more weight to the rotating parts than necessary. -'I'-he present device does away with threads and friction along a consider 45 able portion of the screw member.

Referring now to the drawing, in denotes a casing divided into two compartments, II and I2, in the first of which is'a motor l3. The shaft 14 of the motor extends into the compartment 12 and has journaled thereto a disk IS. The outer edge of the disk has a slotted flange l6 extend-. ing axially into compartment I2. The plane of each of the slots ll is parallel with the axis of" the shaft and is tangent to a. circle about that axis, the position of the slot being such that the rear' wall of the slot as it rotates will smash into fluid coming tangentially from a rotating inner member. An angle of about 20 degrees between the slot and a radius thereto may be used. The slot has a greater speed and a direction of motion differing from that of the liquid. Attached to the disk by bolts I8 is a member I9 with afrustro-conical inner surface 20 coaxial with the shaft, the larger end of which extends into the space between the shaft and the flange 16. This end is provided with radial slits 2|, which may have their greatest angular width at the extreme end of the member 19. The portions of the member i9 between the slits form teeth 22. The forward faces of the teeth, in the rotary sense, may be single radial planes. The rear face of each tooth may be an arcuate surface extending from the tip of the forward face to the base of the forward face of the following tooth, or it may comprise two plane, radial surfaces, one 23- extending from the tip of the forward face backward at an angle with the axis and another 24 substantially parallel to the axis. Such an arrangement leaves a small open space between the bottom of the.

teeth where a large portion of the liquid would tend to spill over and a larger space-between screw extends through the smaller end of the g I tor.

but is also to a certain extent arcuate about the axis. Each film therefore, as it is smashed by the slots in the outer rotating flange, is cut by various slots and forced to commingle with other films. Films of entirely reconstituted formation are finally thrown off by these outer slots. The

teeth and spaces *therebetween are axially in registry with the slots 11.

The disk l5 and member l9 form a distribu- Attached to the shaft l4 and forming an axial extension thereof is a feeding element which may take the form of a screw 25. This The braces also support a sleeve 28 surroundingthe screw. The end of the screw which passes through the ring and the small end of member l9 has threads 29, preferably multiple. The other end of the screw within=the sleeve has threads 30 which 'may be of greater pitch and size than threads 28. The middle portion of the screw is preferably unthreaded, leaving a space 3| between the screw and the sleeve.

Attached over the end of the sleeve removed from the distributor is a valve mechanism adapted for opening and closing that end of the sleeve and operated by a. shaft 32 extending through the casing. The shaft in turn may be operated by the oval arm 33 pivoted to the easing. A portion ofthe seat of the valve may be chamfered as at 34 to facilitate the seating.

Adjacent the compartment Ii and outside the casing is a reservoir 35 from which extends. a conduit 38 through the casing into compartment I2. The'conduit opens adjacent the end of the sleeve 28. The reservoir is preferably placed so close to the axis of the device that for all angles of the axis greater than approximately 20 degrees with the horizontal the liquid in the reservoir will flow under gravity into the end i of the sleeve. It is advisable to have the liquid fiow into the sleeve end so that the screw may carry it to the distributor and suck other liquid from the reservoir as hereinafter described. In certain cases, such as the spraying of ceilings, it is advantageous to hold the device with its axis away from the vertical, and with the reservoirfar from the axis there might be positions of the device where the reservoir would be below the end of the sleeve. The reservoir and conduit are replaceable, when they become empty, by similar refill units. The casing may be restricted in the apron around the end of the conduit and the end of the sleeve. A portion of the casing is cut away at 31 adjacent some of the slots IT.

'A sliding gate 38 is adapted to restrict or close this opening. Fan blades 39 may be attached to the shaft l4 within the compartment II.

The operation of the device is as follows: The motor is started and the distributor and screw rotate. The entire device may be held in the hand. Pressure on the arm 33 opens the valve mechanism. The screw in the sleeve extends below the surface'of the liquid and carries the liquid along the interior of the sleeve. The liquid fills the space 3! and is carried farther by the threads 29 into the member IS. The multiple threadscarry the liquid along the screw 25 so that it does not collect small masses on the narrowest part of the conical surface andrise thereon in pulses, but it is thrown off from the. threads against the conical wall for an appreciabl'e distance, giving a regular centrifugal flow up to the teeth.- Some of the liquidimmediately passes into the slits. The rest rides .up the conicaL surface of the teeth and pours over the various'parts of teeth with the result that a film of liquid passes out past each tooth and has an axial breadth. As hereinbefore described these films are also arcuate and each is of substantially equal thickness at one end as at the other. They present an ordered distribution of material well suited for the smashing and redistrib-- uting to follow.

When these films are caught between the teeth, their rotary. motion is greatly increased because the liquid as it rises on the cone attains but a part of the velocity of rotation of the distributor, due to inertia. Leavingthe teeth tangentially, the films are smashed by the vertical slots with their greater peripheral speed. Theliquid under centrifugal force passes through the slots and is. thrown outward toward the casing. A portion of the liquid passes through the opening in the casing as a thoroughly mixed spray. The remainder is caught by the casing and absorbs the heat which the casing has conducted from the motor. The fans assist in this by keeping the air in the motor compartment in motion. The heated liquid flows under gravity to the pool at the foot of the screw and is ready to repeat the above process. As will be apparent, some heat is absorbed by the liquid as it passes along the shaft.

The pool of liquid at the foot of the screw is Reference'islmade ,tomy copending applica- 65 .sufiiciently deep to seal the end of the sleeve and embody the invention may be made without deof said slots piercing; said element parting from its scope, it is intended that all matter contained inthe above description .or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A liquid-distributor comprising a'rotatable member, teeth on-a. periphery of said member, said teeth being broadest at their base, and a rotatable element surrounding said toothed periphery and having slots adapted for receiving liquid from said member and for spraying said liquid.

2. A- liquid distributor comprising a rotatable member, teeth on a periphery'of said member, said teeth being broadest at their base, and a rotatable element surrounding saidtoothed periphery and having slots adapted for receiving liquid from said member and spraying said liquid, each having an inner frustro-conical surface, teeth on a periphery of said member, and a rotatable element surrounding said toothed periphery and having slots adapted for receiving liquid from said member and for spraying said liquid, screw means adapted for feeding liquid to the smallerend of said-surface, having one end extending into said member and multiple-threaded; having a central portion unthreaded and having anotherend singly threaded, means adapted for supplying liquid to said screw means and comprising a reservoir located substantially near an assumed extension of theaxis of said screw means aliquid to said distributing means, means adapted for actuating said distributing means, means adapted for heating said liquid comprising means for conducting heat from said. actuating means to a portion of said distributed liq id, and

at an angle supplying means. 6. In apparatus of the character described, the

means for returning said heated portion to said .eombination comprising means adapted for distributing a liquid, means adapted for actuating said distributing means, means adapted for cooling said actuating means and for heating said liquid, comprising a casing separately enclosing -said distributing means and said actuating means, said casing adapted for returning a portionof said distributed liquid to said distributing means, and means for circulating the air between said actuating means and said casing.

7. A method of spraying liquid comprising distributing said liquid, intercepting a portion of said distributed liquid, permitting another portion of the distributed liquid to escape as a spray heating said intercepted'portion withexcess heat from the motivating means, and returning said heated portion to be redistributed.

8. In a device of the character described, the

combination comprising motive means, a shaft liquid-containing well beneath said distributor,

a tube leading to said distributor from a point above eth'e bottom of said well, a" rotatableshaft within said tube and extending within said conical surface, screw means at the bottom of said shaft, and means on said shaft providing a plurality of discharge edges at a point within said conical surface, said shaft being smooth intermediate said screw means and said discharge means.

10. A spraying device comprising a centrifugal above the bottom of said well, a rotatable shaftwithin said tube and extending within said conical surface, screw means 'at the bottom'of said shaft, and additional screw means on said shaft 1 providing a plurality of discharge edges at a point within said conical surface, said 'shaft being smooth intermediate the lower and upper screw means.

11. A spraying device comprising a centrifugal .distributor' having a conical inner surface, a

liquid-containing well beneath said distributor, a tube leading. to said distributor from-a point above the bottom of said well, a rotatable shaft within'said tube and extending within said conicalsurface, screw means at the bottom of said shaft, and multiple thread screw means on said shaft providing a plurality of discharge edges at a point within said conical surface, said shaft being ,smooth intermediate the upper and lower screw means.

0 12. A paint spraying device comprising a cen trifugal distributor, means providing awell beneath said distributor, a tube leading to the .in-

: terior ofsaid distributor from a point above the bottom of said well, means to lift liquid from said well through said. tube to'said distributoP/fi a reservoir above said well, a conduit extending fromsaid reservoir to a point within said well above the lower end of said tube and open at its lower end, a housing surrounding the distributor having an aperture for the centrifugal ejectment of liquid, and means for returning excess liquid to the well.

13. A paintspraying device comprising a centrifugal distributor, means providing a well beneath said distributor, a tube leading to the interior of said distributor from a point above the bottomof said well, means to lift liquid from said well through said tube to said distributor, a casing surrounding the aforesaid members, a removable unit providing a reservoir above said well and a neck extending from said reservoir to a point within said well above the lower end of said tube and open at its lower end, a housing surrounding the distributor having an aperture,

for the centrifugal ejectment of liquid, and means for returning excess liquid to the well.

14. Paint spraying apparatus comprising, in combination, screw means adapted, for being positioned at an angle with the vertical and adapted for feeding a liquid; centrifugal means at one end of the screw means adapted for receiving the said liquid from the screw means and for distributing the liquid, supply means adapted for maintaining by gravity a portion of the other end of the screw means under the surface of the liquid being supplied when the axis' of the screw means is at an angle with the vertical, a housing surrounding the distributor having an aperture for the centrifugal ejectment of liquid, and means for returning excess liquid to the base of the screw means.

15. A spraying device comprising a casing formed with an aperture at one side of the device, a hollow centrifugal distributor adapted to eject centrifugally liquid through the said aperture, the casing being arranged to intercept the liq- "uid discharged by the distributor toward the distributor and means for returning excess interrupted liquid to the collection chamber.

16. A. spraying device comprising a casing formed with an aperture at one side of the device, a centrifugal distributor adapted to eject centrifugally liquid through the said aperture, the said casing being arranged to intercept the liquid discharged by the distributor towards the other sides of the device andbeing provided at its base with a collection chamber, a straight tube coaxial with thevsaid distributor and extending directly downwardly from the interior of the distributor and opening into the collection chamber, means within the tube for lifting liquid from the col1ection chamber to the distributor, and means interior of the casing for returning to the collection chamber excess liquid intercepted by the casing.

EDWARD 0. NORRIS.

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