US2651404A - Machine for applying coatings - Google Patents

Description

p 8. 1 3 K. E. JAMES 2,651,404

MACHINE FOR APPLYING COATINGS Filed April 2. 1948 2 Sheets-Sheet l INVENTOR.

BY W5 Sept. 8, 1953 K. E. JAMES MACHINE FOR APPLYING COATINGS '2 Sheets-Sheet 2 Filed April 2. 1948 Patented Sept. 8, 1953 MACHINE FOR APPLYING COATINGS Kenneth E. James, Baldwin Park, Calif., assignor to United Concrete Pipe Corporation, Baldwin Park, Calif., a corporation of California Application April 2, 1948, Serial No. 18,555

Claims. 1

This invention relates to a method and apparatus for projecting or throwing finely divided or comminuted materials at high velocities. The invention is suitable for throwing finely divided materials such as sand in sand blasting, the stock piling of finely divided materials, the segregation of fine particles from coarse particles and the applying of coating materials. As the invention will have a very great use in applying cementitious coatings it will be described in conjunction therewith although it is not restricted thereto.

Heretofore machines for applying coating materials have been provided wherein the coatin material of a certain consistency is by some suitable means thrown against the surface to be coated with suflicient velocity to cause a substantial portion of the coating material to adhere to the surface. Where the coating material is of a cementitious nature it has been found that two important factors largely determines the ultimate compressive strength of the finished coating. These are the density of the applied coating and the water cement ratio. The density of the applied coating is determined largely y the velocity with which the coating material strikes the surface to be coated and it has been found that with cementitious coating the velocity should be in the neighborhood of from 5,000 to 10,000 feet per minute in order to obtain the most desirable results.

In the usual situation the strongest concrete or cementitious coating has only sufficient water to complete hydration of the cement when added to the mixture. From four to five times this quantity is usually required in order to make the mixture suitable for placing. By use of the present invention a relatively dry cement mortar may be employed using very little if any more water than is required to complete hydration of the cement and this relatively dry coating material can be projected or thrown at the required high velocity to secure the desired density on the surface to be coated.

In methods and machines heretofore devised for this general purpose the coating materialor other comminuted material has been. fed onto a fiat or substantially flat endless belt which is traveling in the direction that it is desired to throw the material. The material is usually allowed to fall onto the belt by gravity with the intention of its being brought up to the speed of the belt by reason of its frictional engagement therewith. Then when the belt is diverted from Such direction by passing around a. roller or pulley the materia1 deposited thereon will continue in its initial direction by inertia. Where the particles of the material deposited on the belt are individually of no great mass such. as particles of sand used either in-sand blasting or in cementitious coatings the frictional engagement between the individual particles and the belt surface is insufiicient to bring the particles up to the speed of the belt. In some instances due to the high speed of the belt the particles on falling onto the belt are merely scattered by it instead of being brought up to belt speed. Under these circumstances the speed of the belt must be lowered in order for the particles de-' posited thereon to be brought up to its speed before they are thrown therefrom.

An object of the present invention is to provide a novel method and apparatus for bringing the comminuted material almost instantaneously up to the speed of a belt traveling at high velocity so that the particles can be thrown from the belt in the desired direction and at the desired high velocity when the belt is diverted by passing around a roller or pulley. In accordance with the present invention the comminuted material is fed into an upwardly open bight formed between a reach of the belt and a roller or other moving surface against which the belt is urged in the course of its travel. The comminuted material on being fed into this bight is effectively compressed or pinched between the belt and the roller so that a very high frictional engagement is created between the particles and the belt which is many times greater than that frictional engagement existing when the comminuted material merely rests on the belt by gravity. In this manner it is possible to drive the belt at a very high rate of speed so that the coating material will not only be brought up to the speed of th belt almost instantaneously but Will be thrown therefrom with the desired high velocity and scattering of the material is largely if not entirely eliminated.

In a machine of this character particularly when used to apply coatings it is of considerable importance that the coating material be fed into the bight at a uniform rate or in an evenly distributed manner. I have found if it is desired to apply a smooth coatingthat if'the coating material is fed into the bight unevenly the uneven feeding will result in the material being thrown n an uneven manner so that the applied coatmg will also be uneven. It is therefore another object of the invention to providean apparatus that will evenly feed the coating material t the bight so that the applied coating will be even and relatively smooth.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims. reference is, had to the accompanying drawings for an illustrative embodiment of the invention, wherein: x

Fig. 1 is a view in side elevation of an apparatus embodying the present invention and illustrating it as being employed to apply 'cementie. tious coating to a metal pipe Fig. 2 is a view in side elevation parts bein broken away and shown iifvertigalfsj jl f q portion of the apparatus illustratedin V g. 1;

Fig. 3 is a vertical section taken substantially upon the line 3-3 upon Fig. 2 in the diregtion 7 indicated; 4.118 a 991 012 ew a en. ubst i l y up the 444 11 501 Fig. 2fin the direction a H his a vertical section taken substantially heaccorripanyi e r w n where similar reiference"characters designate sim r prts t oiighoiit, tl'ie projecting or throwing ortion'fbf the apparatus consists essent 1'! of an ehdless' beltf "1 which is trained oyer p: efpulleywr roller II and an idler pnlieyo ro The drive pulley H may be driven in any [ftablefmanner such as by a belt or' chain i? a from 'afvariablespeed electric motor It The upper r apn of this endless belt passes beneathamidler'roller or pulley l5 so as to be epr s d thereby: an to. rm a ul w Open bightfllif lie fbelt' is continually urged against the 'underside o'f' the roller Ifij'with considerable force "bythe initi al tension of the belt and the comminutedmaterial or coating material indicatedati'i fecldnto the bight. The ends of the bight' may beclosed such as by side plates 18 theflbottom edge's of which are shaped to conform to theferterior'of the roller [5" and the portion orreacliof the belt'that leads from roller 12 th roller-15 to thus confine the material 11 "After passing beneath the roller Hi the belt is directed in the direction that it is desired to throwthe coating material-or as illustrated that portion of the belt -running from the underside of rollen I5- to the 'drive 'roller H is directed toward a metal pipe "-P*-which in this instance constitutes' the surface to becoated. The pipe P is illustrated as having been mounted'on a suitable carriage "I 9- for longitudinal movement with re lation to the belt; The pipe isalsomounted on the carriage for rotarymovement about its longitudinal axisso that thecoating maybe evenly distributed thereon as the machine isoperated. In'otherwords'the pipe P while being rotated abouttits longitudinal. axis is movedwith the carriage in a longitudinal or axial direction in frontrofv ,the. belt. so that the coating applied thereto will1be'. applied-in a generally helical mann n AS-13 16 apparatusisoperated thefinely divided lalnriw I is e lcat rely cqmpressedor pinched have? h bel ."Lah thgundersid of l e ,t b Trcss qn f its'h sh ct na ga mi l tl i hltiielbitT fieto th -pressur p sed byfr'tiiei rs t 'wi'llfbe falmostinstantly brought upfto the h gh speed at which the belt may be L" Arteipf sing. beneath the rollerl5 alfifihfik h a e t he re ch f the extendingtdward the top of drive roller ll I5 Soit traveling the and will be thrown from the belt toward the pipe P when the belt is diverted around the drive roller. In applying cementitious coatings with this apparatus the sand and cement are merely dampened with water sufiiciently to supply the water required for hydration of the cement and when thrown at the highl'v'ellocity. (5 ,000 to 10,000 feet per minute) a verylarge proportion of the coating material will adhere to the surface to be coated. When the cement sets it will be found that itv is. not, only, of the desired high density but as the amount of water used is very low that a very strong cementitious coating can be obtained. any suitable means for feeding the comminuted materialifitd thbight [B may be employed but where it is desired to throw the material from the belt in a highly uniform rate so as to secure a'veiy even application of the coating the material ll must be fed-into the bight at a highly uniform rate; 1f fedunevenly the coating applied will be" likewise uneven. In. order to secure an even feeding-of the material into the bight lfiI mploya'hopper 2U=int0 wh-ichthedngredients ofth'e" coating such as. sand, cement and water may bedumped. A paddlevmixer. 21 is disposed inthe bottom of=thisehoppen and has helically arranged-paddles mountedthereon in opposite directions so as to-feed the-.materialin the course of-mi-xing toward. a centralaoutletsine dic'ated at 22 This outlet. can. be controlled by a gate 23. The paddle mixer may be drivenin any suitable mannercsuchrasflhy atchain. 2.4..frp a'i'notor 25* The-ingredients. .oftthe coatingmar terial after. havirigbeen. mixed. by tha. paddle mixer are constantlyied through. the; qutlet 2 2 past the. gate 23 onto. an endless-belt 2!); arranged therebeneath. Ali-langedi roller 21; is. rotatably mountedon.v a, transverselvextending, shaft; 2 5,- This flangedlrolleraisnrrangedbehind.thaoutlet 22v and haslitshflangescontactingiwith the belt 2 8 This. flanged roller is. .designcd'itd ,sh fl; h material. lLthatJs.depositedon the beltzintq an even moundreferably .oitrapezoid shapein, cross section. Asa meansfor so, shaping this mound and. causing. it. tabs .of, suitably. uniform dQDSity the shaft. 283s equ pDQiWiiiha gear flmwhich meshes with ageanal drirenbyac aih s nd sprockets .Off. ioffla ,fiQullbfili-Shhfiifin ThQc Qlm-Wl? shaft. astmay he..driven .siicha 51 a; hh nfl from an electric motor 35 The driverollerjgi for.theaf0rwardi.. nd.i frtheibelt imay alsg be mountcdcnt cuntcr h it 3 sq that. K 9 ell zfi-tcanlbe rii'enthem rha t hsegisei he hams Stand 4a eir.remedive hitkhh andt c. scars-. hand/BU e abling t e; f amed l el: 1 ensata er h ral reed-semis}.- rably.higher. ank ngs t h.-; el 'rh fla gssimllcn 21, arts, rites in wi l: emindithe mra e. sall i ifi l eqt sr ov emo eme'n e ie-h 12 3 2199 whereto, its rot Dur n aii a n-91 qin whai trowel. or smooth. oil", th'a material" I T- that is do.- posited on the belt and to worh the,material into a mound whichgis of. .unliio height and p of uniforniimaiii iiiziflwiqth. As a means 1? in tow.

1 whic r .p mta n q ii ih fihar thabcltth m f 28.

The above described construction serves to deliver from the hopper auniform amount of material I! that is to be fed into the bight. This material may drop from the belt 26 by gravity as it passes over the drive roller13'. However, as the material I! in'the case ofcementitious'jcoatings is damp and consequently will tend tooling together when smoothed off by the roller 21, it is desirable to prevent the material from extending beyond the end of roller 36 'andthen falling into the bight in the form of lumps. To this end a gear 4! is mounted on the end of the countershaft 33 meshing with a spur gear 42 on a rotary shaft 43. The shaft 43 carries a series of parallel discs 44 which are arranged in the path of the mound as it passes over the drive roller 36. These discs may be rotated at a suitable speed in either direction with relation to the direction of movement of the mound so that the discs will tend to break up the mound and cause it to fall freely and uniformly into the bight It. In this manner although the cementitious material may be deposited unevenly on the belt 26 from the hopper the roller 21 will tend to arrange the material in a uniform mound which is carried by the belt toward the bight. Then the material as it falls from the belt over the roller 36 is effectively broken up by the rotating discs 44. Where the comminuted material that is to be thrown at high velocity is of a dry nature such as in sand blasting such elaborate precautions of feeding the material into the bight need not be resorted to and the same is true when the apparatus is used merely for stock piling comminuted materials or separating fine from coarse particles. In making such separations although all particles will be discharged or thrown at the same initial velocity the wear resistance on the small particles will cause these particles to lose their velocity quicker than large particles so that an effective separation may be accomplished.

The improved apparatus may also be employed to apply cementitious coatings to canal walls and the faces and approaches of earth filled dams and when so used the entire apparatus may be mounted on a tiltable turntable that can be turned and tilted to vary the direction in which the coating is discharged from the belt I 0.

The velocity at which the belt I is driven may, of course, vary with different materials but velocities at which the belt is driven for most cementitious coatings will normally be between 5,000 and 10,000 linear feet per minute. The arrangement and velocity of the belt 26 should be such that the material discharged therefrom will fall by gravity into the center of the bight I 6. It is undesirable to allow the material on belt 26 to fall directly against the upper surface of the belt I!) due to the fact that this belt under normal conditions will be traveling at such high speed that the material will merely slide thereon without being brought up to speed and will be merely scattered by it. By feeding the material into the center of the bight a pinching action between the belt and the roller I5 immediately commences with the result that the frictional engagement between the material and the belt is such that the material is almost instantly brought up to the speed of the belt Ill.

The belt [0 is preferably formed of some yieldable material such as a rubber coated or rubber impregnated fabric and the roller I5 may similarly be coated with rubber or rubber-like material.

Various changes may be made in the details of 6 construction without departing from the spirit and scope of the invention as defined by th'e'appended claims.

1. An apparatus for applying coatings 'of-materials at high velocity which includes an endless belt, means for driving the belt, movable means against which the belt presses and arranged to cooperate therewith to form an upwardly open bight into which the coating material may be fed whereby the material can be quickly brought up to the speed of the belt by being pinched between the belt and the movable means, and means for feeding the coating material into the bight comprising an endless belt, means for depositing the coating material thereon, means for shaping the coating material on the belt in a continuous uniform mound, said belt being arranged to discharge into the bight, and means for breaking up the mound as it is discharged from the belt into the bight.

2. An apparatus for applying coatings of finely divided materials at high velocities comprising an endless belt, a roller depressing the upper reach of the belt and cooperating therewith to form an upwardly open bight, means for feeding material into the bight, there being a roller over which the belt is trained after passing beneath the mentioned roller so that the material after being pinched between the roller and the belt and brought up to the speed of the belt will be carried thereby in the direction in which it is desired to throw the material, the feeding means including an endless belt on which the material is deposited which conducts the material to the top of the bight and means for breaking lumps of the: material as it is fed from the last mentioned belt.

into the bight.

3. An apparatus for applying coatings of finely divided materials at high velocities comprising;

and brought up to the speed of the belt will' be carried thereby in the direction in which it is desired to throw the material, the feeding means including a, second endless belt on which the materialis deposited, a roller over the second endless belt for pressing the material into a mound thereon, means for rotating the last mentioned roller and means for breaking up the mound into finely divided material as it falls from the second endless belt toward the bight.

4. An apparatus for applying coatings of finely divided materials at highvelocities comprising an endless belt, a roller depressing the upper reach of the belt and cooperating therewith to form an upwardly open bight, means for feeding material into the bight, there being a roller over which the belt is trained after passing beneath the mentioned roller so that the material after being pinched between the roller and the belt and brought up to the speed of the belt will be carried thereby in the direction in which it is desired to throw the material, the feeding means including a second endless belt on which the material is deposited, a roller over the second endless belt for pressing the material into a mound thereon, means for rotating the last mentioned roller, and a plurality of circular discs in the path of the mound of material on the second 7 endless belt as the material masses therefrom into-the blght and means -for rotating said discs.

5. A mechanism for feeding finely-dividedmaterial into a throwing apparatus therefor including an-endless belt on which the material is deposited, means -for driving said -belt, a flanged roller arranged thereover adapted to shape the material carried 'by the belt into a mound thereon, means "for rotating the fianged roller, a plurality of dises 'arrangedin the path of the mound where it --leaves the endless belt and means for rotating said discs.

KENNETH E. JAMES.

atmaioi ReferencewGlted m the flle of this :patent YUNITED sTATEs 'PHTEN'IS Number "Name Date Schmidt May 10, 1892 Piette May 14, 1895 Borrowe July '18, 1899 Iym'an'l. Aug. 13, 1901 Sehieldr'op Mar. 9, 1926 Johnston- Apr. 14, 1931 1-'\;afltii0 Aug. 30, 1938 'Rlissll NOV. 4, 194'?

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