US1977321A

US1977321A - Method and apparatus for applying materials to surfaces

Info

Publication number: US1977321A
Application number: US542257A
Authority: US
Inventors: Louis G Merritt; Ericsson H Merritt
Original assignee: LAMINATING PATENTS CORP
Current assignee: LAMINATING PATENTS Corp
Priority date: 1931-06-05
Filing date: 1931-06-05
Publication date: 1934-10-16
Anticipated expiration: 1951-10-16

Description

9ct. 16, 1934. L. G. MERRlTT-Er AL 19977321 METHOD AND APPARATUS FOR APPLYING MATERIALS TO SURFACES Filed June 5. 1931. 4 Sheets-Sheet l INVENTORS.

Oct. )16, 1934. L. G MERRITT ETAL 1,977,321

METHOD AND APPARATUS FOR APPLYING MATERIALS T0 SURFACES Filed June 5. 1931 4,*Sheets-Sheet 2 JNVENTORS a, M Y I ATTORNEYS.

' @et 16, i934. IL, G| MERRITT EfAL 1,977,321

METHOD AND APPARATUS FOR APPLYING MATERIALS TO SURFACES Filed June 5. 1931 4 Sheets-Sheet. 3

INVENTORS. Y

Oct. E6, 1934. L. G. MERRITT ET AL 1,977,321

METHOD AND APPARATUS FOR APPLYNG MATERIALS TO SURFACES Filed June 5. 1951 4 Sheets-Sheet 4 :9 INVENTORS. M Amm M Patented Oct. 16, 1934 METHOD AND APPARATUS FOR APPLYING MATERIALS TO SURFACES Louis G. Merritt and Ericsson H. Merritt, Lockport, N. Y., assignors, by mesne assignments, to Laminating Patents Corporation, Seattle, Wash., a corporation of Delaware application .time 5, i931, serial No. 542,257

l2 Claims.

This invention relates to methods and apparatus for disseminating powdered materials,and, more particularly, for the application of powdered materials to surfaces of articles such, for example, as veneer sheets and the like.

An object of the invention is to provide improved methods and apparatus of the character under consideration.

Another object is to provide a method whereby powdered materials may be applied to surfaces of articles in a particularly uniform manner.

A further object is to provide a method whereby powdered materials containing particles of varying sizemay be readily, effectively and uniformly applied to surfaces of articles, and particularly to surfaces of moving articles.

Another object is to provide apparatus of the character under consideration for readily and elfectively applying powdered materials to the surfaces of articles.

Another object is to provide apparatus of the character under consideration whereby powdered materials may be applied to the surfaces of articles in a particularly uniform manner.

Another object is the provision of improved means for applying powdered materials tothe surfaces of moving articles.

Another object is to provide means for eifectively applying to the surfaces of articles a powdered material containing particles of varying size.

An additional object is the provision of .apparatus of the character indicated which is relatively simple in construction, which can be readily assembled, and in which parts may be readily removed for repair and replacement: which will operate in a particularly uniform marmer, and which will eciently accomplish the purposes for which it is intended.

Other objects of the invention will in part be Jbvious and will in part appear hereinafter.

The invention accordingly'comprises the several steps and the relation and order of one ir more of such steps with respect to each of ;he others, and the apparatus embodying fea- ;ures of construction, combinations of elements md arrangement of parts, all as exemplified in yhe'following detailed disclosure, and the scope if the application of which will be indicated in `he claims.

For a fuller understanding of the nature and bjects of the invention reference should be lad to the following detailed description taken n connection with the accompanying drawings, n which:

Figure 1 is a view of a form of apparatus-exemplifying the invention in vertical section along the line 1-1 in Fig. 3;

Fig. 2 is an enlarged detail showing of the 60 central portion of Fig. 1; Y

3 is a view at right angles to Fig. 1 in vertical section along the line 3-3 in Fig. 4; and

Fig. a is a side view of the apparatus.

The problem of applying powdered material to surfaces of articles, as, for example, in applying coating materials inl powdered form or in applying powdered adhesive materials to surfaces to be glued has proved a matter of considerable4 dimculty, particularly in instances wherein an especially high degree of uniformity in the spread of the powdered material on the surfaces was desired. 'I'hat there are many such instances will be readily apparent when it is considered that the appearance of coated articles often depends upon the uniformity of the coating applied, and that in the gluing art the strength of the bond is often dependent upon a high degree of uniformity of. spread. Again,- where the coating material or the adhesive material is of a relatively expensive nature the desirability of limiting the spread to a minimum throughout the entire area of the surface to which the material is applied will be readily apparent.

With the foregoing and otherends in View, the present invention contemplates the provision of methods and means whereby various factors hav ing tendencies away from a maximum of uniformity may be desirably controlled and various diiiiculties overcome.

vThe invention pnovidesfmethods and mea'ns in the performance and use of which more orless of a varietyof desirable steps may be performed in a desired sequence. While in the more specie aspects of the invention, all, or at least several, of such steps will :be performed, the invention in its broader aspects is not limited to the performance of a. method involving, or the use .of apparatus for performing, any particular num- 100 ber or sequence of such steps.

As an example 4of a methodsuch as contein-V plated -by the invention reference may be had to a procedure which may be conducted by the ap-' paratus hereinafter described, and which involves continuously disseminating above moving articles, such as veneer sheets or the like, a stream of particles substantially as wide as the sheets,

breaking up the stream so-as'to assure thatV the particles will not be associated in globules or in. 111111.01.' streams, and directing a. current of air against the broken-up stream,` so as to carry par.-

ticles evenly and regularly onto the moving sheet. Where the particles to be disseminated are contained in a receptacle, it is'desirable to replenish f the particles continuously and. preferably at a controlled and substantially uniform rate, and

it is also desirable that lthe particles 1to ybe sup-r plied be agitatedl in many instances One form of apparatus such as contemplated by the invention and such as utilizable in carry-f ing out the methods contemplated by the inven tion isr exemplified in the drawings.

This apparatus comprisesja.r container l0 yfor holding a massof powdered material, across the bottom of which there extends a portion of an endlessbelt 11 of `forarninate construction. Such a belt may desirably be formed of cloth or wiremesh and is adapted to be supported on a plate 12 which is preferably formed of .rubber firmly vulcanized toia platel 13 carried by the framework of* the machine. 'line belt is adapted :to pass into the container -undera bar y11i on aside plate 15 and: after travellingbeneath a mass of particles 16 in the container and receiving'such,

particles in itsinterstices-r passes out of the container between the bevelledend 17 of the 'plate' i2 and a rubber cylinder i8 on aroller i9.A In' order to assure that the`r powdered material will drop outof lthe interstices of the belt as the latter clears the end l'l of the plate l2, therer ispro-'f vided a vibrator roller 20, the periphery-of which is formed with protuberances 2l which are adapted dwing-rotation t0 jai the belt which is heldr tight lby means; hereinafter to ybe exemplied.

f .in order to assure that only the particles withinl the interstices of the belt will lbe carried from lthe contairner,y the roller 19 is rotated, preferably relatively slowly,. in a direction such that its surface will move inwardly andA upwardly'as it entersA l the container, amd in order to prevent particles which are desirable for use in the formation of plywood and similar procedures the particles of the material will have a tendency more or less to cohere, and for the purpose of breaking up globules thus formed, as well as for other purposes including the smoothing out of any unevenness in the film or stream of particles, a suitable break-up element is disposed in the path of movement of the particles. As exemplified, this element consists of a rotatable roll 25 having its downwardly moving side in the path of the stream of particles falling from the points where the belt leaves the edge 17 of the support 12. It is to b'e noted that the particles tend to follow an arcuate course along the side of this roll due to the natural induction of the air surrounding the roller.

The diiculties in providing a spread having a high degree of uniformity attend especially a procedure wherein the size of the particles to be sprayed is irregular, i. e. where the material to be spread consists of both coarse and ne particles. This is not only the case wherein a mixture of two materials of relatively different size is utilized; but also in all cases where it is desired to avoid the necessity of using a powder of which the particles are of substantially the same size,

with the attendant expense and waste involved 1ny the lprovision of such a powder.

` In order to avoid the tendency of casual air currents to vary the movement of. theparticles beneath the roll 25y and tor separate the finer particles from the coarse-r as well as to dissipate certain of the finer particles, and also in order to Aguider the .particles in an even and substantially uniform manner in a desired direction toward the surface to be coated there is providedmeans for ejecting a jet of air againstthe. stream at a point ldownwardly soA as todirect a current of air, just under the roller 25, in a direction transverseto the f stream of the falling particles and. downwardly, with the result that these particles will assume courses generally between a sharply inclinedr y;

plane anda less inclined plane above the same,

'the' heavier particles following a course adjacent the sharply inclined plane, and the lighterparf ticles following a course adjacent the less inclined plane. f A current of. air is carried into the nozzle member 27 from a blower' 3l at oneside of: the machine through a `conduit comprising opening .'Bla, dampening chamber 31h and opening 32.

The current is smoothed out tol provide; an even outward how throughout the length of the space between'the plates 28 and 29 by meansl of barile members 32a extending transversely. of the nozzle member .27..y f y The current of air issuing from between'the members 28 and 29 provides lalmovinginclined support. on which the particles toboggan" to th surface on which they are to be'spread. f

It is desirable that lthe velocity of lthis air` l current be just enough to overcome the tendency of natural or prevailing air-currents to influence the falling powder. For example, under conditions where no extraneous air currents are set up outside the machine a desirable velocity, at the point where the air leaves the nozzle portion may be about feet per minute for 200 mesh particles, may be from to 200 feet per minute for material 90% of which would pass through 100 mesh and Ll0% of which would pass through 150 mesh; and may be 230 feet per minute for material all of which would pass through 80 mesh and 30% of which would pass through 150 mesh and which contained a relatively small percentage of i'lnes. rllhe foregoing gures are apparent velocities, based upon readings of an anemometer (Tycos No. A105, outside diameter of the blade circle 3% inches, inside diameter 1% inches, width of blade .one inch on outside circle and il inch on inside circle) placed with its center particles have different weights; a higher velocf ity being used with powders having a greater Weight per particle.

The surfaces of the articles upon which the particles are to be received may be arranged in any 'desired manner for the reception of these The particles referred to are those of an through the path of flow of the particles, as, for example, on a suitable conveyor. In the present instance, there is provided a conveyor 33 arranged to move sheets 34 of veneer or the like along a plane which is relatively close to the roll 25 and through the cloud of particles indicated at 30.

The surfaces may be moved in any desired dlrection with respect to the direction in which the particles are carried by the air current. In the present instance, the movement of the sheets is exemplified as being in a direction opposite to the horizontal component in the direction of movement of the particles. Such an arrangement is of advantage in certain instances, as, for example, when relatively non-coherent particles are being applied to a relatively adherent surface, for instance, a moist surface, since the finer particles will rst contact with the adherent surface. Eective results, are secured, however, in a large number of instances when the direction of movement of the sheets is the same as the horizontal component of the direction of movement of the particles.

It will accordingly be seen that the present invention is of value in carrying out various gluing 'methods such, forexample, as 'that disclosed in the application of Theodore Williams Dike, filed February 28, 1931, Serial No. 518,944, and which has matured into Patent Number 1,869,957, issued August 2, 1932.

Powdered material may be supplied to the container 10 in any suitable manner, but is prefer-l ably supplied thereto at a uniform rate and in controlled amounts.. To this end there is provided at a point above the container a trough-like container 35, the bottom wall of which is provided by a plate 36 having formed at one side of its center line a series of openings 37, and above the plate 36 there is disposed an adjustable plate 38 having a series of similar openings 39 adapted to coincide with the openings 37. For the adjustment of this plate there is provided a handwheel 40 carrying a screw 41 extending into a threaded opening in a bar 42 secured to the plate 38. Accordingly, by the movement of the handwheel the size of the channels provided by the

openings

37 and 39 may be reduced to any desired extent. l

Powdered material is supplied to the troughlike container from a hopper 43, and movement of the powdered material past the openings, as well as continuous agitation of the material in the trough-like container is assured by causing a continuous circulation of the material as by means of a pair of parallel oppositely-moving spiral conveyors 44 and 45.

The endless belt 11, which may be supported and driven in any suitable manner, is, as exemplified, carried from the vibrating roll 20 over a roll 46 and thence over rolls 47, 48 and 49. Prior to passing into the container. the belt passes over av roll 50. Between the

rolls

49 and 50 it passes inwardly about a tensioning roll 51, the shaft of which is journalled in boxes 52 and 52', which are adapted to slide'between ltrack

members

53 and 54, and 53 and 54', respectively. A movement of the roll to eiect the tensioning of the belt may be. vcaused by the adjustment of a tension rod 55. It

is to be noted that in the construction indicated the roll 51 may be readily slipped in place after the endless belt has been positioned over the other rolls and may readily be removed merely by loosening a securing means, such as the bolt and nut "attachment shown at 56. The tension rods 55 are suitably fitted at their outer end to pass through tension-adjusting wheels 57, which, acting through spaced sleeves 58, serves to bear against an equalizer bar 59. A weighted tension lever 60 is suitably connected to the central portion of the equalizer bar 59 as through link pins 61, 62 and 63, link 64 and clevis 65. A shaft 66 is disposed to pass between portions of the framework. The tension weight 67 is attached to the lever 60 by means of gibs 68 in a manner which allows for a wide vrange of movement of the ing articles-the air delivery means. A combina tion of such elements provides a particularly effective means'for the spreading of powdered materials and especially satisfactory results have been found to be obtained by the use of apparatus similar to that exemplified. However, in certain of its broader aspects the invention contemplates the provision of a variety of forms of apparatus embodyingone or more of the types of elements set forth and adapted for use in various ones of a wide number of procedures.

'I'he exemplified apparatus embodies a form of conveyor which has been found particularly de sirable for use in methods such as those underk consideration. As exemplified, the conveyor 33 comprises a single endless cable 70 extending back-and-forth over drums 71 and 72 which are provided with annular grooves 73 for the reception of the cable.' During a portion of its run from4 one end of the drum 72 to the other end of the drum 71, the cable passes about'sheaves 74 and 75 which are carried, respectively, on brackets 76 and 77. 'I'he brackets are adjustably mounted between

rails

78 and 79, and 80 and 81, respectively, so that they may be slid to a position to suitably tension the cable. adjusted position by suitable means such as the nuts 82 and 83, respectively.A Suitable means (not shown) may be'provided for driving one or the other of the drums 71.and 72; such means may include variable speed mechanism of any well-known type, if desired.

Suitable means are likewise provided for driving the other movable elements of the apparatus. In this connection it is to be noted that the foraminate belt or screenV preferably moves at a relatively slow speed, in certain instance, for example, two, three or four feet per minute. It is desirable, in many cases, that variable speed mechanism be provided in the driving means for this belt so that the `quantity of material disseminated may be readily controlled.

' In the present instance there is provided a driving motor`106 from the shaft of which rotative motion is transferred by a sprocket 107, a chain 108, and a sprocket 109 to the constantspeed shaft 110 oiv a variable-speed mechanism indicated generally at 111 and which may be of any well-known type, as, for example, the coneand-belt type. On the variable-speed shaft 112 of the variable-speed mechanism there is carried .a gear 113 meshing With a reduction gear 114 They are held inv Sense.

carried for the sake of simplicity of construction on the shaft 110, in the present instance, but freely movable thereon. Carried on the gear 114 is a small gear 115 meshing with a secondary reduction gear 116 which carries a sprocket 117 connected by a chain 118 with a sprocket 119 rotatably mounted on'a stud 120. Carried on the sprocket 119 is a smaller sprocket 121 from which a chain 122 extends to a sprocket 123 carried on the shaft of the drive roll 49 for the screen. There is also carried on the sprocket 119 a sprocket 124 from which a chain 125 extends over a sprocket 126 carrying a gear 128 meshing with a gear 129 mounted on the shaft of the doctor roll 19.

The shaft 110 also carries a sprocket 130 from which a chain 131 extends to a sprocket 132 rigidly keyed to one of the ends of the break-up roll 25. A second sprocket 133 rigidly mounted beside the sprocket 132 imparts its motion through a chain 134 to a sprocket 135 rigidly fixed to one of the ends of the Vibrator roll 20.

The drive for the spiral conveyors is an independent unit in the present instance, due to the somewhat remote locations of these conveyors. A motor 136 supported on a bracket 137 imparts its motion through a coupling 139 to a worm gear speed reducer 140 from which the reduced rotative speed is further conveyed to the' spiral conveyors'through a sprocket 141, a chain 142 and a sprocket 143.

The term dry air as used herein is intended to refer to air to which droplets of moisture have not been added.

Since certain changes in carrying out the above method and in the constructions set forth, which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawings shall` be interpreted as illustrative and not in a limiting 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 a matter of language might be said to fall therebetween.

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

1. The method of applying powdered material to a surface, which comprises causing a movement of the surface, directing generally toward said surface a stream of particles at a rate substantially just suicient for the desired coating of the moving surface and'directing against said stream a current of dry air moving in a direction transverse to said stream and toward said surface and so regulated that material quantities of particles will not be removedfrom said surface by said current.

2. The method of applying powdered material to a surface, which comprises causing a movement of the surface, directing generally toward said surface a stream of particles at a rate substantially just sufficient for the desired coating of the moving surface and directing against said stream a current of dry air moving in a direction transverse to said stream and opposite to the direction of movement of said surface and so regulated that material quantities of particles will not be removed from said surface by said current.

3. The method of applying powdered material to a surface, which comprises directing a curtain of particles in a given direction, breaking up any globules or independent streams of particles embodied in said curtain, moving a surface beneath said curtain, directing against said curtain a current of dry air in a direction generally transverse to said stream and toward the surface to be coated and in a manner such that substantially all the particles directed toward said surface will be evenly deposited on said surface.

. 4. The method of applying powdered material to a surface, which comprises causing a relative movement of a container for powdered material and a surface to be coated, supplying a continuous controlled ow of particles of material to said container, withdrawing material from said container at a uniform rate substantially just suncient for the desired coating of a surface during such movement, directing the withdrawn particles in a stream toward the surface of an article to be coated, and guiding the iiow of particles toward said surface by directing against said stream la current of dry air so regulated that material quantities of particles will not be removed from said surface by said air current.

5. Apparatus for applying powdered material to surfaces comprising means continuously to measure out uniform quantities of powdered materials and to uniformly discharge measured amounts of material from the measuring device,

means to separate the individual particles of the material so discharged, and means for directing a current of dry air upon the separated particles whereby said particles are guided to a surface to be glued.

6. Apparatus for applying powdered material to surfaces, comprising means including an endless foraminate belt to disseminate a powdered material, and means to guide the disseminated material toward the surface of an article.

7. Apparatus for applying powdered material to surfaces, comprising means including an endless foraminate belt to disseminate a powdered material, and means to direct a current of air relative to the disseminated material toguide the same toward the surface of an article.

8. Apparatus for applying powdered material to surfaces, comprising means to disseminate a powdered material, said means including an endless foraminate belt and a rotary vibrator member, and means to guide the disseminated material toward the surface 'of an article.

9. Apparatus for applying powdered material to surfaces, comprising means providing a container for materials, means including an endless belt'for withdrawing materials from lsaid container, means including a Vibrator member to remove withdrawn materials from said belt, and means to direct the withdrawn materials against a surface to be coated.

10. Apparatus for disseminating powdered materials, comprising a'n endless foraminate belt, means to cause said belt to receive powdered material in the openings thereof, and means to remove powdered materials from the openings in said belt.

11. ApparatusA for disseminating powdered materials, comprising an endless foraminate belt, means to cause the belt to receive powdered material in the openings thereof, and means to vibrate the belt to cause the removal of particles from said openings.

12. Apparatus for disseminating powdered materials, comprising an endless foraminate belt, means for maintaining a mass of material above a portion of said belt, means to drive said belt,

and means tp cause materials received in the openings of said belt to fall therefrom at a given point in its path.

13. Apparatus for disseminating powdered materials, comprising an endless foraminate belt, a supporting surface for a portion of said belt, means tovprovi'de the side-walls of a container above said supporting surface, means to drive said belt, and means to cause the material received by said belt in the openings thereof to fall therefrom at the point where said belt leaves said supporting surface.

14. Apparatus for disseminating powdered materials, comprising an endless foraminate belt, a supporting surface for a portion of said belt, means to yprovide the side-wallsl of a container above said supporting surface, said means including a doctor roller disposed with its periphery adjacent one edge of said supporting member, means to drive said belt, and means to cause the material received by said belt in the openings thereof to fall therefrom at the point where said belt leaves said supporting surface.

15. Apparatus for disseminating powdered materials, comprising an endless foraminate belt, a supporting surface for a portion of said belt, means to provide the side-walls of a container above said supporting surface, said means including a doctor roller disposed with itsv periphery adjacent one edge of said supportingmember, means to drive said belt, means to-drive said doctor roller in a direction such that its periphery moves rearwardly with respect to said endless belt, and means to cause the lmaterial received by said belt in the openings thereof to fall therefrom at the point where said belt leaves said supporting surface.

16. Apparatus for applying powdered materials to surfaces including means to move a surface in a given path, means to disseminate a powdered material, and means to provide a low velocity current of dry air to direct the powdered material upon said surface.

17. Apparatus for applying powdered `materials.

to surfaces including means to move a surface in a given pathmeans to cause a flow of material in a curtain toward said path of movement, and means to direct against the flowing material a current of dry air moving transversely to the curtain and toward said path of movement.

18. Apparatus for applying powdered materials to surfaces including means to move a surfacein a given path, means to' cause a continuous now of powdered material in a given plane, means interposed in the path of flow of said material for breaking up any aggregations of particles and delivering the particles in a single stream, and means for directing' a current of dry air against the delivered stream whereby the particles may be directed against the moving surface.

vet

19. Apparatus for applying powdered materials to surfaces including means to move a surface in a given path, means to cause a continuous ow of powdered material in a given plane', means interposed in the path of flow of said material for breaking up any aggregations of particles and delivering the particles in a single stream, and means to direct a slowly moving current of dry air against the said stream to direct the particles against a surface.

20. Apparatus for applying powdered materials to surfaces including means to move a surface in a given path, means to cause a flow of material in a curtain toward the path of said movement, and means to direct against the owing material a current of dry air moving in `a direction toward moving surface and opposite to the direction of movement thereof, said directing means being arranged so that the air current while moving in said direction contacts said flow on its way to said pathr 21. Apparatus for applying powdered materials to surfaces including means to move a surface in a given path, means to cause a continuousiiow of powdered material in a given plane, a break-up roll having its axis disposed at one side of the path of flow of said material and having one side of its periphery in said path of flow, means to' rotate said break-up roll with said side moving in for a portion of said belt, means to provide the side-walls 'of a container above said supporting surface, means to drive said belt, and means to cause the material received by said belt in the openings thereof to fall therefromv at the point lwhere said belt leaves said supporting surface;

means interposed in the path of flow of said material for breaking up the same; and means for directing the broken-up material against the moving surface.

23. Apparatus for applying powdered material to surfaces, comprisinga container, means for supplying a continuous controlled flow of particles of material to the container, means for withdrawing material from the container at a uniform rate,` and means for controlling the ow of particles toward a'surface and including means for supplying a low velocity particle-guiding current of dry air.

24. The method of applying powdered material to a surface, which comprises causing a movement of the surface directing generally toward said surface a curtain of particles extending transversely of the direction of movement of said 120,.

surface, and directing against said curtain along a line above said surface a current of dry air moving in a direction transverse tovsaid curtain and toward said surface -to alter the course of the particles in the general direction of the current, 12 the course of the finer particles being altered to a greater extent than the course of the coarser particles.

25. The method of applying powdered material to a surface, which comprises causing a movement of the surface, directing toward said surface a curtain of particles extending transversely of the direction of movement of said surface, and directing against said curtain along a line above said surface a current of dry air moving at a low velocity in a direction transverse to said stream and towards said surface to alter the l course of the particles in the general direction of the current, the course of the ner particles being altered to a greater extent than the course of the coarser particles. l 26. The method of applying powdered material to a surface, which comprises causing a curtain of particles to be delivered in a givenA direction, causing a relative movement of said curtain and 145 a surface, and directing a slowly moving dry air current in a direction transverse to said curtain and toward `said surface to guide the particles of material to the surface.

27. The method of applying powdered material to a surface, which comprises causing a movement of the surface, directing a stream of particles generally toward said surface, and directing a current of dry air against said stream in a direction transverse to said stream and toward said surface and in such manner that the particles will move toward said surface at an angle thereto and will move over a course fan-shaped in cross-section with the heavier particles at theside of the course nearest the point of entry of the air current.

28. Apparatus for applying powdered material to surfaces, comprising means providing ancontainer, means including an endless foraminate belt for withdrawing materials from said container, means to move a surface along a given path, means to remove particles of material from said belt and to direct a stream of the removed particles toward said path, and means to direct an air current against said stream and toward said surface.

29. Apparatus for applying powdered material to surfaces, comprising means to move a surface in a given path, means to cause a transversely extending stream of material to move generally toward said path, a break-up roll interposed in the course of now of said stream,` and means to direct a transversely extended dry air current against said stream immediately below said breakup roll and in a direction transverse to said stream and toward said surface.

30. Apparatus for applying powdered material to surfaces, comprising a measuring device, means to discharge measured amounts of material from the measuring device in a uniform curtain, means to separate any aggregations of particles in the curtain into individual particles, and means to deliver upon the particles a current of dry air so regulated that `they will be guided through a free space above a surface and uniformly deposited thereon.

31. Apparatus for applying powdered material to surfaces, including an endless foraminate belt, a member contacting with the underside of said belt and having' a transverse edge, means to maintain powdered material above said belt at a point adjacent said member to ll the openings in said belt, the last-mentioned means including a doctor member, means to move said belt past said maintaining means and over said edge, and means disposed beyond said edge in the direction of movement of said belt for vibrating said belt and discharging the powder from the openings therein at a point adjacent said 32. Apparatus for applying powdered material to surfaces, including an endless foraminate belt, a member contacting with the underside of said belt and having a transverse edge, means to maintain powdered material above said belt at a point adjacent said member to ll the openings in said belt, the last-mentioned means including a doctor member, means to move said belt past said maintaining means-and over said edge, means disposed beyondv said edge in the direction of movement of said belt for vibrating said belt and discharging the powder from the openings therein at a point adjacent said edge, a breakup roll disposed beneath said edge with its axis beyond the same in the direction of movement of said belt, and means to rotate said break-up roll in .a direction such that its side under said edge moves downwardly.

33. Apparatus for applying powdered material to surfaces, including an endless foraminate belt,

a member contacting with the imderside/of said belt and having a transverse edge, means to maintain powdered material above said belt at a point adjacent said'member to fill the Vopenings in said belt, the last-mentioned means including a doctor member, means to move said belt past said maintaining Vmeans and over said edge, means disposed beyond said edge in the direction of movement of said belt for vibrating said belt and discharging the powder from the openings therein at a point adjacent said edge, a break-up roll disposed beneath said edge with its axis beyond the same in the direction of movement of said belt, means to rotate said break-up roll in a direction such that its side under said edge moves downwardly, ymeans to move a surface in a path under said break-up roll in a direction perpendicular to its axis, and means to direct in a plane just under said break-up roll and in a direction opposite to the direction of movement of its underside and downwardly a current of air having just sufficient velocity to guide the particles toward a moving surface and deposit them thereupon.

34. Apparatus for applying powdered material to surfaces, including means to provide a curtain of powdered material moving in a given direction, a break-up roll disposed in the path of said curtain and arranged to receive the particles on a side thereof moving in the direction of movement of the particles, and means to direct a current of dry air in a plane just under said break-up roll and from the opposite side thereof and downwardly.

35. Apparatus for applying powdered material to surfaces, comprising means for moving a. surface along a path, means including an endless belt to provide a curtain of powdered material moving generally toward a surface moving along said pathVand means to direct against said curtain a current of air moving in a direction transverse to said curtain and toward said surface and at a speed just vsunicient to guide the particles to said surface.

36. Apparatus for disseminating powdered materials, comprising an endless foraminate belt, a supporting surface for a portion of said belt, means to provide the side-walls of a container above said supporting surface, said means including a doctor roller disposed with its periphery adjacent one edge of said supporting member, means to drive said belt, means to drive said doctor roller in a direction such that its periphery moves rearwardly with respect to said endless belt, and means to cause the material received by said belt in the openings thereof to fall therefrom at the point where said belt leaves said supporting surface, said means including a vibrator member.

37. Apparatus for applying powdered material to surfaces, comprising means to cause a transversely extending stream of material to move toward the path of movement of a surface, and means to direct a current of dry air against said stream along a line spaced from said path and in a direction transverse to said stream and toward said path, said directing means being in such position that the air current while moving in said direction contacts the stream before it reaches said path.

38. Apparatus for applying powdered material to' surfaces, comprising means to cause a transversely extending stream of material to move toward the path of movement of a surface, and means to direct a low velocity dry air current -los powdered material may be withdrawn over said supporting surface, a doctor member for limiting the amount of material withdrawn by said belt, and means to cause the material withdrawn by said belt to fall therefrom at a point where said belt leaves the supporting surface, and means to direct a current of air upon the stream of parti-v cles after it leaves the belt.

40. Apparatus for applying powdered. material to surfaces, comprising an endless foraminate belt, a supporting surface for a portion of said belt, means providing a container from which powdered material may be withdrawn over said supporting surface, a doctor member for limiting the amount of material Withdrawn by said belt, means to cause the material withdrawn by said belt to fall therefrom at the point where said belt leaves the supporting surface, break-up means disposed in the path of movement of the falling particles, and means to direct an air current on the particles after they are acted on by the break-up means.

41. Apparatus for applying powdered material to surfaces, comprising means including an endless foraminate belt for continuously withdrawing quantities of material from a mass, means-including a vibrator member for discharging the withdrawn material in a curtain, and means to direct a slowly-moving current of air against the curtain.

42. Apparatus for applying powdered material to surfaces, comprising means to cause a curtain of particles to fall toward the path of movement of a surface, and means for directing a laterally extended current of dry air against one side of said curtain to guide the particles to the surface, said directing means including a restricted ejection channel of substantially uniform extent leading rearwardly from the ejection opening.

LOUIS G. MERRIIT; ERICSSON H. MERRI'IT.