US1772907A - Machine for applying coatings - Google Patents

Description

Aug. l2, 1930. H. c. MAcAN ET AL MACHINE FOR APPLYING COATINGS Filed May 17. 1928 2 Sheets-Sheet 1 62 fg 63 5/ if Fig a.

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Aug. l2, 1930. H, c, MACAN ET AL 1,772,907

MACHINE FOR APPLYING COATINGS 2 Sheets-Sheet 2 Filed May 17. 1928 INVENTOR 4 ATTORNEYS Patented Aug. 12, 1930 UNITED STATES PATENT oFFlcE HARRY CONARD MACAN, F RUTHERFORD, CHARLES E. YATES, OF EAST RUTHERFORCD, AND WILLIAM M. SHAKESPEARE, OF SOUTH ORANGE, NEW JERSEY, ASSIGNOBS TO ANACONDA SALES COMPANY, OF NEW WARE Application led May 17,

This invention relates to the art of applying coatings to objects, and is concerned more particularly with the provision of apparatus for the application of coating material to a succession of objects of similar shape and slze. The apparatus is especially adapted for the application of a dry coating material 1n the form of a finely divided solid, and 1t` adords important advantages. in producing electroconductive coatings on non-metallic objects, as, for instance, by coating these objects w1th a thin .layer of conductive powder, such as graphite or the like. An embodiment of the invention suitable for that purpose will therefore be described in detail for purposes of illustration, though it will be apparent, that the utility of the invention is by no means limited to this particular use.

One of the recent developments in theroofing industry is that of a metal platedshingle which is of composite form consisting of a base of a non-metallic material, such as ordinary roofing felt and a layer of weat-herresistant metal, such as copper, plated on the base as a thin coating which protects they base against the weather, and improves its resistance to fire and also its general appearance. In one commercially successful form, this material includes a base of roofing felt 3o of the usual type, impregnated and coated with as halt and having a layer of granular materia such as crushed slate or the like, artially embedded in the asphaltic coating.

ver this granular layer is then applied a coating of metal by electrodeposition andthe application of such a process necessitates the provision of-an electro/conductive surface on which the metal can be deposited. The presence of the grit on the surface of the base to be plated improves the quality of the product because it gives the metal a texture which is pleasing to the eye and in addition it rovides a means by which the metal and ase can be securedly bound together by a mechanical interlock. The application of an electroconductive material to produce the conductive layer for plating purposes on this irregular grit surface involves some difculties and heretofore this operation vhas 60 been carried on in numerous ways. Attempts YORK, N. Y., CORPORATION OF DELA- MACHINE FORAPPLYING COATINGS 192s. smal No. 278,440.

these practices hasl not been entirely satisfactory, and when adhesive is used it adds to the cost of the nal product and also to the difiiculty of applying the coating uniformly and in a thin layer.

The present invention is directed to the provision of apparatus by which a thin and uniform coating of a solid substance may be applied to the surface of an object. In the case vof a grit-coated shingle which is to be given a conductive layer, the conductive powder is distributed over the shingle by this apparatus in such a way that the coating is of uniform thickness and does not obscure the crests and depressions in the surface which result from the presence of the grit. Graphite thus applied thinly avoids concealment of the irregularities and in addition a saving in the cost of the material is effected and accumulations are revented which are not bound {irmly to the Ease s'o that metal plated over these accumulations would have a tendency to separate from the base. Also, by this apparatus the graphite or other substance is distributed over the entire surface of the base which it is intended to plate regardless of the character of that surface, and in addition, the edges of the shingle are likewise coated with graphite, so that the plating may extend down around these edges, thus affording protection to the shingle on the edges of that end which is normally exposed to the weather.

The preferred form of the apparatus i11- cludes a receptacle in which the finely divided conductive material is contained, and beneath the receptacle is a conveyor, preferably in the form of an endless belt, a part of this conveyor forming the lower end closure of the receptacle and thus supporting the mass of conductive substance in the receptacle. This conveyor is provided with projections so that the shingles may lie lat on the belt to be carried along by the projections, and the conveyor is arran ed so that that stretch on which the shing es are placed is inclined at an angle to the vertical. Preferably the conveying stretch lies at an angle of about 45, and the shingles are carried the conveyor in separated relation upwardly beneath the mass of conductive substance to which they are directly exposed as they pass beneath the receptacle. As the shingles are moved from beneath the mass of conductive powder, they are first acted on by suitable means for removing the excess powder, su'ch as a revolving brush, and this excess graphite is thrown upon a sieve or other similar devlce by which the graphite is freed of any foreign substances, such as fine pieces of slate which might be removed from the face of the shingles by the action of the brush. This brush removes the major part of the excess, but as its action may not be complete, the shingles next pass through a chamber maintained under a partial vacuum. Here the surface of each shingle is acted on by an air blast which removes such particles of the coating substance as are not firmly adherent to the Wbase, and these particles are freed from the shingle by the action of another rotating brush or like device. The graphite removed from each shingle in this chamber is carried oi by suction, separated from the air in a suitable separator, and then dehvered back to the mass in the main receptacle. In order to avoid difficulties from dust, this main receptacle is entirely enclosed, and means are provided by which the supply of conductive substance in the chamber may be replenished from time to time without openin the receptacle.

For a better understanding of the invention, reference will be had to the accompanying drawings, in which,

Fig. 1 is a view in side elevation, partly in section, of the new apparatus,

Fig. 2 is a plan view of the same,

Fig. 3 is a view partly in side elevation and partly in section on the line 3-3 of Fig. 1,

Figs. 4 and 5 are sectional views of alternative replenishing means,

Fi 6 is a sectional view on the line 6--6 of Fig. 2, and

Fig. 7 is a plan view of a portion of the conveyor showing shingle members thereon.

Referring now to the drawings, the apparatus'is illustrated in the form suitable for the coating of multiple shingles, such as that shown at 10 in Fig. 7. These shingles may be made of any suitable material, but ordinarily consist of a base of asphalt-impregnated felt coated with asphalt and carrying a layer of granular material, such as crushed slate, on

their upper surfaces. These shingles are provided with cutout notches 11 defining separated tabs 12, the notches extending inwardly from one edge of the shingle so that each shingle unit when laid has the same appearance, by reason of the separated tabs, as that of three individual shingles laid in spaced relation and in the usual courses. Metal is now to be'applied to the up er faces of these shingles and preferably t e metal extends downwardly around the forward edge 13 and along the exposed edges 14 of the felt in the cut-out notches. Accordingly, the conductive material must be applied so as to cover the upper face of each shingle and the front edges, including such portions of those edges as lie in the notches. For this purpose the apparatus illustrated in Fig. 1 is used. This apparatus comprises a triangular frame 15, a portion of which lies on the floor atI any convenient location, and includes an upright 16 and the inclined member 17. The frame is double and the sides are secured together by suitable cross members, such as 18.

Supported in suitable brackets 19 mounted in any convenient manner, as, for example, on the subframe member 20 is a drive shaft 21'driven in any suitable way, as by a motor 22 mounted on an extension 23 from the ramei On this drive shaft is a sprocket wheel 24 over which runs a chain 25 driving a sprocket wheel 26 on a shaft 27 supported in suitable bearing brackets 28 Aat any convenient' point, as on the upright frame member 16. The shaft 27 carries a sprocket wheel 29 driving a sprocket wheel 30 on a cross shaft 31 mounted in bearings 32 on the inclined frame member 17 The shaft 32 carries a drum 33 around which extends an endless conveyor belt 34, extending around a drum 35 mounted on a shaft 36 in bearings 37 on the frame member 17 near the lower end thereof. This belt is provided with spaced,

rows of pins 38 for engaging and moving the shingles along with the belt in the upward travel of the latter.

In the upper stretch the belt which suports the shingles runs over a table 39 formlng part of a housing 40 which encloses the greater part of the belt. The belt has lateral flanges 41 at either side and the table 39 has an overhang 42 at each edge, secured to which is a guide strip 43, these guide strips bearing on the face of the belt between flanges 4l and thus centering the belt. The guide strips are selected so that the distance between them is not substantially greater than the length of a multiple shingle 10 which is to be coated in the apparatus.

At one end the housing 40 has an upright portion 44 supporting a table 45 on which a stack 46 of the shingles to be treated may be placed, and this table has an inclined portion 47 lying close to the surface of the belt. A roller 48 rests on the surface of the belt and is held in position by means of the extension the shingles to be treated are laced one byA one against the surface of the lt and held in position by the roller until a row of pins engages the rear edge of each shingle, as shown in Fig. 7, and carries this shingle along as the belt moves.

Disposed above the upper stretch of the belt is a housing 50 forming a receptacle for a mass 51 of the finely divided coating substance, in this case graphite. The lower end of this housing is open to the belt so that the belt forms a closure for the housing and a support for the mass of graphite which has a tendency to accumulate 1n the pocket formed between the belt and one vertical side 52 of the housing. This vertical wall of the housing extends close to the face of the belt and at this side is provided an extension housing 53 which is hinged at 54 to the vertical wall 52. This housing contains a heavy bristle brush 55 which is supported so as to bear against the face of the shingles as they are moved upwardly by the conveyor, the brush removing any loose particles of grit or foreign matter which the shingles carry. The brush likewise serves to prevent the escape of powdered material through the opening between the vertical wall 52 of the housing and the belt through which opening the shingles enter the receptacle. In the extension housing 53 there is also mounted a` loose roller 54 which bears by gravity against the faces of the shingles as they are carried upwardly by the belt, the roller serving to prevent the escape of graphite which may have passed beneath the bristle brush.' By reason of its hinge mounting, the extension may be raised clear of the belt so that the brush may be examined and cleaned from time to time.

In the operation of the device the workman places one shingle at a time against the face of the belt and in contact with the roller 48. Then as a row of pins comes into os1- 'tion, these pins engage the rear edge o the shingle and carry the shingle along with the belt. The shingle passes first beneath the roller 54 and then the brush 55, eventually entering the receptacle 50. Here the shingle is pushed upwardly beneath and in contact h with the main mass of coating powder and the powder adheres to the face of the shingle and to the forward edges. The notched edge, it will be observed, is forced through the mass of powder so that the faces of this forward edge, including the portions defining the notch, are pushed against the graphite mass, thus insuring that all portions of these edges will be covered with graphite which is pressed against these edges and the face of the shingle by reason of the movement of the shingle upwardly against the weight of the mass. As the shingles leave the mass carried along by the belt, a considerable quantity of powder adheres to them, thus forming a coating which is much thicker than is required and contains much excess material. To remove this, mechanism is provided which operates in two stages.

The housing 50 has an upward extension 56 lying parallel to the belt, and in this extension is a device for removing excess material which may take the form of a rotating brush 57. This brush is mounted on a shaft 58 extending through the wall of the housing and supported in the ends of arms 59, the other ends of which are secured to a sleeve 60 mounted loosely on a shaft 61 extending across the machine and mounted in suitable bearings in fra-me members 61 secured to the inclined frame member 17. The shaft 58 carries a sprocket wheel 62 at one end driven by a chain 63 running on a sprocket wheel 64 on the shaft 61, and shaft 61 carries a sprocket wheel 65 driven by a chain 66 from a sprocket wheel 67 mounted on the shaft 27. Owing to the manner of mounting the shaft 58 in the ends of pivotally mounted arms 59, the brush 57 rests on the shingles by its own weight and as this brush is rapidly rotated it removes the excess graphite from the shingles passing upwardly beneath it. This excess material is thrown by the brush upon a screen 68 lying within the housing 50. The screen is supported on a rock shaft 69 extending through opposite walls of the housing and having a crank 7() driven by an arm 71 provided with a strap 72 extending around an eccentric 73 on the shaft 21, The rod 71 is reciprocated, causing the screento4 be rocked and the material removed from the shingles by the brush and deposited on the screen is thus cleaned. The action of the brush is likely to free particles of slate or other foreign matter from the shingles as well as remove the excess graphite, and it is undesirable that these im purities should mix with the graphite. The screen is of a size suiiicient to prevent the return of the impurities into the body of graphite and these particles of foreign matter move along the screen and enter a trough 74 at one end which has a discharge opening 75 (Fig. 3) discharging the material into an outlet spout 76 through the Wall of the ousing.

The extension 56 of the housing has a partition wall 77 dividing the extension into two chambers, in one of which lies the brush 57. Beneath the end of the wall is a roller 78 resting on the top of the shingles. A fla-p 7 9 secured to the extension 77 bears on topof this roller, the two providing a means for shut-V in flanges to which the arms 59 and 83 are secured. These sleeves are loose on the shaft 61, thus not interfering with its rotation. The shaft 82 carries a sprocket wheel 82 on which runs a chain 85 running over a s rocket wheel 86 on the shaft 61. As revious y mentioned, the shaft 61 is` driven y the motor 22 through various connections and thus the brush 81 is likewise driven.

The upper end of the extension 56 includes a wall 87 which extends toward the belt, and a roller 88 suitably mounted lies beneath the end of the wall and bears against the shin les on the belt. A flap 89 secured to the wal 87 bears against the top of the roller, the roller and flap thus providing a closure between the wall and the belt which does not interfere with the movement of the shingles beneath the wall. Leading from the chamber 8O and the extension 56 1s a duct 90 leading to the intake of a motor-driven fan 91. This fan creates a suction in the chamber through which excess graphite removed from the faces of the shingles by th'e action of the brush 81 is withdrawn from the chamber. In order to facilitate the removal action and to loosen the excess graphite, there is provided an air pipe 92 supplied with air under pressure and terminating in a nozzle lying within the chamber and discharging air on the shingles just before they are acted on by the brush 81. This air blast frees excess material which is then forcibly removed by the action of the brush and thrown clear of the shingles, whence it may beremoved by the air suction. The fan delivers the air and graphite to a separator 93 of any convenient type at the bottom of which is a hopper 94 in which the graphite is dropped. This hopper has a duct 95 leading to a feeding means by which raphite may be moved through a duct 96 W ich leads to the upper part of the receptacle 50 through one wall thereof, The receptacle is closed and the feeding means permits the replenishment of the graphite therein without openinv the receptacle.

l:The feeding means may take various forms, and is illustrated in Fig. 3 in the form of a plunger 97 operated by a pivoted arm 98.

The plunger has the same size as the cylindrical duct 57 and when the plunger is moved to its rearward position, graphite from the duct 95 enters the duct 96 in front of the plunger, so that when the plunger is pushed inwardl graphite is moved through the duct 96 and ischarged into the upper part of the receptacle 50. In the receptacle is hopper 98 through which this material is discharged upon the surface of the reciprocating screen 68 so that foreign matter may be removed. The feeding means is so constructed that the parts are sealed at all times and means is provided for introducing additional quantities of graphite into the receptacle by the action of the feeding device. This means inshown in Fig. 4 or cludes a h o per 99 open at the bottom to the duct 96 an fresh graphite is placed in the hopper and flows into the duct so that as the plunger is operated, quantities of new and used graphite are introduced into the receptacle 50 at each operation.

Instead of usin the reciprocating manually-operated fee 1n means 98, the devices ig. 5 may be employed. In Fig. 4 the feeder includes a shaft 100 carrying a feeding screw 101, they shaft being driven by a pulley 102. This feed screw extends through the duct 96 beneath the end of the ho per 99 and the bottom of the duct 95 and) provides a continuous feed which maintains a seal on the receptacle.

` In the modified form shown in Fig. 5, the duct 96 is of gradually increasing size toward the receptacle and the feed screw 103 has flights of increasing diameter, releasing the graphite from compression as it is moved toward the receptacle without destroying the seal maintained on the receptacle.

After the shingles have been passed through the receptacle and beneath the devices for removin' the excess material, they are carried out beneath the upper roller 89 and are carried by the belt beneath the sleeve 84, then moving over the upper drum 33 to be discharged upon a roller conveyor 104 mounted on a table 105 `supported on frame members 106. The coated shin les are then carried away and are ready to e placed in the plating apparatus.

It will be seen that this apparatus is particularly adapted for the application of a coating of a finely divided solid substance to a succession of objects of similar size and shape, and by reason of the fact that these objects are moved on a conveyor which closes the bottom of the receptacle containing the mass of coating material, the weight of the coating material acts to apply this substance to the surfaces to be coated. The excess material is then removed in successive stages so that a thin and uniform layer of the substance is applied to each article. The excess material is returned for further use and in its cycle foreign bodies which may be removed from the articles are separated from the mass of coating substances. Where graphite is used, it is especially im ortant that the apparatus be enclosed so t at the graphite'be kept from escape, not only because of the cost'of the graphite, but also because of difficulties which might arise from mixture of the graphite and air. With the apparatus it is found that the shingles may be coated uniformly and at a rapid rate, and the coating a plied is continuous so that a continuous p ating may be deposited over the conductive layer so produced.

We claim:

1. Apparatus for coating urposes which comprises the combination of) a gravity feed receptacle for the coating material, a conveyor for the objects to be coated, this conveyor acting as a closure for the receptacle and conveying the objects through the receptacle in contact with the coating material therein, and means for removing the excess material 'from the objects after their passage through the receptacle.

2. Apparatus for coating purposes which comprises the combination of a gravity feed receptacle for the coating material, a conveyor for the objects to be coated, this conveyor also'forming a support for the material in the receptacle and moving the objects through the latter in contact with the material therein, and means for removing the excess material from the objects after their passage through the receptacle.

3. Apparatus for coating purposes which comprises the combination o a gravity feed receptacle for the coating material, a conveyor for moving the objects to be coated along an inclined path, this conveyor acting as a support for the material within the receptacle and carrying the objects through the receptacle in contact with the material, and means forremoving the excess material from the objects after their passage through the receptacle.

4. Apparatus for coating purposes which comprises the combination of a gravity feed receptacle for the coating material, a conveyor for moving the objects through this receptacle, with the objects exposed to the entire body of material, this conveyor acting as a support for the material in the receptacle, and means for removing excess material from the objects after their passage through the receptacle. j

5. Apparatus for coating ,purposes which comprises the combination of an open-bottom receptacle for the coating material, a conveyor moving beneath the open bottom of the receptacle and acting as a support for the material therein, means on the conveyor for moving objects to be coated through the mass of material in the receptacle, and means for removing the excess material from the objects after their passage through the receptacle. 6. Apparatus for coating purposes which comprises the combination of a receptacle for the coating material, a conveyor for the ob' jects to be coated, this conveyor acting to move the objects through the receptacle beneath the mass of material therein, the conveyor providing a support for the said material whereby the weight of the material rests on the objects on the conveyor, and means for removing the excess material from the objects after their passage through the receptacle.

7. Apparatus for coating purposes which comprises the combination of an open-bottom gravity feed receptacle, e conveyor for moving ob'ects upwardly along an inclined path beneat the 'receptacle and in contact with the body of material therein, and means beyond the receptacle in the path of travel-'of theobjects for removing the excess material therefrom.

8. Apparatus for coating purposes, which comprises the combination of a receptacle for the coating material, a conveyor for the objects to be coated moving these objects through the receptacle beneath the material in such manner that the objects are exposed to the mass of material resting with its full weight on the objects, and means for removing excess material from the objects and returning it to the receptacle.

9. Apparatus for coating purposes, which comprises the combination of an open-bottom receptacle for the coating material, a conveyor for moving the objects beneath the receptacle and exposed to the mass of material therein, the conveyor providing a support for this material, and means operating in two stages for removing the excess material from the objects and returning it to the recepacle. 10. Apparatus for coating purposes, which `comprises the combination of an open-bottom receptacle for the coating material, a conveyor for the objects to be coated moving these objects beneath the bottom of the receptacle in such manner that the objects are exposed to the entire mass therein, the conveyor providing a support for this mass, means within the receptacle for removing the excess material from the objects and returning it to the mass, and means disposed farther along in the path of travel of the objects for loosening and removing excess material from the objects and returning it to the receptacle.

11. Apparatus for coating purposes, which comprises the combination of an open-bottom chamber for the coating material, a conveyor disposed beneath the bottom of the chamber and forming a support for the material therein, this conveyor moving the objects through the chamber beneath and in-contact with the mass of material, and means acting on the objects' after their passage through the v material for removing the excess material therefrom.

12. Apparatus for coating purposes, which comprises the combination of an open-bottom chamber for the coating material, a conveyor closing the bottom of the chamber and supand means for removing foreign bodies from the material thus removed prior to its return to the main mass of material in the chamber.`

' 13. Apparatus for coating purposes which comprises the combination gf a receptacle for the coating material, an endless conveyor havin a portion continuously acting as a support or the material in the receptacle, this conveyor being adapted to move the objects to be coated through the receptacle in contact with the material therein, and rotary means actin on the objects on the conveyor after they ave been coated for removing the excess material therefrom.

14. Apparatus for coating purposes which comprises the combination of a receptacle for the coating material, an endlessconveyorhaving a portion continuously acting as a supporthfor the material in the receptacle, this conveyor being adapted to move the objects to be coated through the receptacle in contact with the material therein, means for loosening the excess material from the objects, and means for removing the loosened material therefrom.

15. Apparatus for coating purposes which comprises the combination of a receptacle for the coating material, a conveyor for the objects to be coated, this conveyor acting as a support for t-he material in the receptacle and moving the objects through the receptacle in contact with the material, means for removing excess material from the objects after their passage through the receptacle, means for feeding the material thus removed to the receptacle, and means for adding fresh material to the material thus removed to be fed with the latter to the receptacle.

16. Apparatus for coating purposes, which comprises the combination of a receptacle for the coating material having a closed top and and an open bottom, a conveyor for the objects to be coated, this conveyor having a portion acting as a closure for the bottom of the receptacle and a support for the material therein, means on the conveyor for moving the objects through the receptacle in contact with the material therein, and means contacting with the conveyor and the objects thereon for preventing the escape of material from the receptacle at the open end thereof.

17. Apparatus for coating purposes, which comprises the combination of a receptacle for the coating material having a closed top and an open bottom, a conveyor movable beneath the receptacle and providing a closure therefor and a support for the material within the receptacle, means disposed adjacent the receptacle walls and contacting with the conveyor for preventing the escapement of material from the receptacle while permitting the passage of objects on the conveyor through the receptacle, and means acting on the objects after they have come into Contact with the material in the receptacle for removing excess material therefrom.

18. Apparatus for coating purposes which comprises the combination of a receptacle for..

coating material, a conveyor for the objects to be coated arranged to pass these objects into contact with the material, means disposed within the receptacle for removing excess material from the objects on the conveyor after they have been coated, and means disposed outside the receptacle for removing additional excess material.

19. Apparatus for coating purposes which comprises the combination of a receptacle for the coating material having an open bot-tom, a conveyor for the objects to be coated having a portion movable in an inclined plane beneath the receptacle and exposed to the material therein, means on the conveyor for moving objects to be coated through the recep tacle in contact with the coating material therein, means for removing excess material from the objects after they have been moved into contact with the material, the said means acting to return the material to the receptacle, and means within the receptacle receiving the returned material and operative to remove foreign bodies therefrom, `the means last mentioned acting to return the cleaned material to the mass of material in the receptacle.

20. Apparatus for coating purposes which comprises the combination of a conveyor movable in an inclined plane, a receptacle disposed above the conveyor and arranged to contain a quantity of material lying upon and supported by the conveyor, means on the conveyor for carrying objects to be coated through the mass of material Within the re ceptacle, means contacting with the conveyor for preventing the escape of material from the receptacle, the said means permitting the introduction of the objects on the conveyor into the receptacle, and means for removing excess material from the objects after they have been coated and returning the said material to the receptacle.

21. Apparatus for coating purposes which comprises the combination of an endless conveyor having a stretch extending in a horizontal plane, a rece tacle disposed above the said stretch for con ning a quantity of material which lies upon and is supported by the conveyor, means on the conveyor for moving objects to be coated through the mass of material supported thereon, means for removing excess material from the objects and returning it to the receptac1e,and means for adding additional material to the mass within the receptacle.

22. Apparatus for coating purposes which comprises the combination of a conveyor'movable in an inclined plane, a receptacle dis posed above the conveyor and having a closed top, the bottom of the receptacle being closed by the conveyor, and this receptacle confining a quantity of material for coating purposes supported by the conveyor, means on the pnveyor for moving the objects to be coated through the quantity of material supported thereon within the receptacle, means for removing excess material from the objects after they have been coated and returning this' material to the receptacle, and means Pfor introducing additional material into the receptacle While maintaining a seal thereon.

23. Apparatus for coating purposes which comprises the combination of a conveyor, a receptacle disposed thereover for confining a quantity of coating material which is supported by a portion of the conveyor, means on the conveyor for moving objectsto be coated through the receptacle in contact with the material contained therein, means for removing excess material from the objects after they have been coated and returning it to the receptacle, and means for supplying additional material to the receptacle for replenishment of the supply therein, the said ad itional material being combined by the said means with that removed from the objects and being returned.

24. Apparatus for coating purposes which comprises the combinationA of a conveyor, a receptacle disposed thereover for confining a quantity of material which is supportedwithin the receptacle by the conveyor, means on the conveyor for moving objects to be coated through the receptacle in contact with the material therein, pneumatic means for loosening excess material from the objects after they have been coated, means for removing the loosened material, and pneumatic means for returning the said removed material to the receptacle.

25. Apparatus for coating purposes which comprises the combination o an inclined conveyor, a hopper for coating material disposed above the conveyor, this hopper having an open bottom across which the conveyor moves, whereby the conveyor supports the coating material within the receptacle, a driven rotating brush for removing excess material from the objects after they have been coated, an air blast acting on the objects to loosen the coating material therefrom, a second brush for removing the'loosened material, and pneumatic means for withdrawing the loosened material and returning it to the receptacle.

26. Apparatus for coating purposes comprising the combination of a conveyor, a hopper disposed above the conveyor and having an open bottom across which the conveyor passes, the hopper serving to confine coating material which rests upon and is supported by the conveyor, means on the conveyor for moving objects to be coated through the material in contact lwith the coating material therein, means for removing excess material from the objects after they have been coated, and a reciprocating screen within the hopper for receiving the removed material, removing foreign bodies from it. and returning the cleaned material to the mass within the hopp In testimony whereof I afix my signature.

HARRY CONARD MACAN. In testimony whereof I affix my signature.

. CHARLES E. YATES. In testimony whereof I aiiix my signature.

WILLIAM M. SHAKESPEARE.

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