US1896638A - Apparatus for coating sheet material with granular material - Google Patents

Description

Feb- 7, 1933- *.1. c. MaclLDowlE 1,896,638

APPARATUS FOR COATING SHEET MATERIAL WITH GRANULAR MATERIAL `Filed Aug. 30, 192e 3 sheets-sheet l Feb. 7, 1933. Q MaGlLDOwlE A 1,896,638

APPARATUS FOR COATING SHEET MATERIAL WITH GRANULAR MATERIAL Fil-Led Aug. 30. 1926 5 Sheets-Sheet 2 fnvenor @70h72, CfacfZdOu/L' e am 7W aZZfqS Feb. 7, 1933. J, c, MaclLDowlE 1,896,638

APPARATUS FOR COATING SHEET MATERIAL WITH GRANULAR MATERIAL Filed Aug. 3o, 192e 3 sheets-sheet s Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE JOI-IN C. MACILDOWIE, F NASHUA, NEW HAMPSHIRE, ASSIGNOR TO ASBESTOS WOOD & SHINGLE C0., 0F NASHUA, NEW HAMPSHIRE, A CORPORATION APPARATUS FOR COATING SHEET MATERIAL WITH GRANULAR MATERIAL Application filed August 30, 1926. Seria1 No. 132,360.

Yface of sheet materials or the like.

'In the manufacture of various materials it is often desirable either for decorative or utilitarlan purposes to apply a coatlng of Y granular material to the surface or surfaces.

Means and methods have heretofore been devised for accomplishing this result and are of constant application in the several arts. However', such methods and the means for carryingl them out are in general characterized by being directed to the application of a uniformly distributed coating of the granular material (as exemplified by sand paper) orelse they are intended for or inadvertently result in the application of a regularity of depositsl which are subject to frequent repetition in the course of continued operation of the process.

In some instances, however, as for ex` ample where the artistic appearance of the finished surface is a factor to be reckoned with, it is desirable that the granular material shall not be regularly distributed and,more over, that it shall not be subject to repetition of pattern, at least within relatively extensive areas of the surface treated. A typical case where such conditions are desirable is found in sheet materials for architectural purposes, such as rooting and shingles. Insuch applications, it is well recognized that large areas of perfectly plain and uniform coloration are monotonousand that, on the other hand, any repeated sequence of variations (resulting in a more or less regularly dened pattern) is equally repugnant to those seeking to attain a pleasing aesthetic effect in the final general appearance of the structure, whatever it may be.

Although vari-colored granular materials lhave been employed in the processes of the prior art, it has been found that they do not result in producing any appreciable irregularity in the coloring of the sheet to which they are applied, but that they produce a composite shade which results from the blending nf the several colors together. Moreover, it

is found that even the most careful handling lwill not avoid such admixture or blending of the materials,.and that, on the other hand, if they are purposely kept apart and applied independently to the surface in accordance with prior practices, such applicationresults in a streaky or banded product which is very objectionable.

It is, therefore, an object of the invention to provide a method by which one or more granular materials may be applied to surfaces, Whether in small or large units, to form an irregularly distributed layer or discontinuous coating without appreciable repetition, with more or less permanent xation of the thus applied granules to the surface.

The procedure of the invention includes providing means for emitting the granularV material (as by passing the same through a plurality of exit openings characterized by being irregularly spaced andof irregular sizes and/or shapes) fpreferably further scat- I tering the discharge om such openings as by through a suicient height to disperse the same and, together with the intervening column of air, to scatter the granules in patches upon the sheet to be coated, the surface being concurrently moved relative to the discharge so asv to continually receive the irregular de- -posit throughout all or the desired portion of the surface to be treated in this manner. The thus applied deposit is then fixed in situ, as by pressing the same into the surface, or equivalent means to e'ect intimate contact and adhesion thereto.

A preferred and representative example of the method and means for carrying out the invention will be described in its adaptation for applying several kinds'of granular materials to cementitious sheets forthe making of shingles, reference being had to the aecompanying drawings, in which Fig. 1 is a side elevation of the apparatus employed;

Fig. 2 is a plan view of the same;

Fig. 3 is an end elevation;

Fig. 4 isa side elevation in enlarged detail of the batlies and tripper mechamsm; and 1 Fig. 5 is a plan view of a finished shingle.

impact, and permitting it to fall by gravity Referring to the drawings, numerals 1, 2, 3 and 4 indicate successive distributor means standing above a table or conveyor 5 and severally consisting of a hopper 6, and a cylinder 7 rotatably mounted upon its horizontal axis and revolved by means of a chain 8 driven from pulley 9.

Each hopper 6 opens at the lower end into a horizontal hollovs7 tube 11 which forms the axis of the cylinder 7 and has a longitudinal slightly helical slit extending throughout the length of its under side (not shown). An extended portion of the tube 11 is permanently mounted upon the frame 14. The tube 11 contains a screw-threaded worm 10 which passes completely therethrough and is rotatably mounted to form the axle of geared wheels 16 adapted to be engaged by linked sprocket chains 8 which pass over and connect the corresponding geared wheels of the adjacent units in pairs. Thus, the worm '10 of unit 1 is directly driven from pulley 9 by belt 17, while the sprocket wheels of units 2, 3 and 4 are driven by connection with the succeeding sprocket chains 8 and gears 16. The cylinder 7 of each unit is coaxial with the tube 11 and closed at the ends by solid walls (not shown) which constitute bearings to receive the tube 11, projecting therethrough.

Alxed to each cylinder 7, preferably at the end of the unit opposite to the geared wheels 16 already mentioned is a large geared wheel 18 adapted to engage sprocket chain 8. The chain 8 passes over the geared wheel 18 of each unit and under intermediate gears 19 mounted upon frame 14, and thence by a loose return to the source of driving power, pulley 9. As thus arranged, each of the worms 10 is positively rotated by operation of pulley 9 and chain 8 and sin'iultaneously therewith each of the cylinders 11 is driven by the same pulley 9, and hence in step with the worm, by the chain 8. They may, however, be independently driven if desired and for some purposes such independent drive may be found advantageous.

The peripheral surface or wall 21 of each cylinder 7 is provided with irregularly spaced apertures 22, 22 which are of unequal sizes and preferably also of different shapes. They may also be covered by strips of coarse or of fine wire screen 23.

Placed beneath the cylinder and longitudinally parallel thereto are oppositely inclined baiie plates 24, 25. One of these bafi'le plates (shown as 25) may be afiixed to a rod 26 at its upper edge, the ends of which are received by upright vibrator springs 27. One of the latter, in turn, passes up through a horizontal rod |28 at its free end. The end of the rod 28 is provided with a projection 29 adapted to engage a ratchet wheel 31 which may also be driven by belt 32 from pulley 9.

Passing below the ballie plates 24, 25 of each of the units 1, 2, 3, 4Vand mounted upon a suitable support is a conveyor 5 consisting of horizontal belt 33 leading from beneath a storage bin 34 having a bottom exit 35 to permit the withdrawal (by the forward movement of the belt) of a layer of a cement-asbestos mixture contained therein. The belt then passes under a rotating brush 36 and thence beneath each of the distributors 1, 2, 3 and 4 above described, in succession, followed by compression roller 37, a water sheet 38 and cutting knife 39 if desired.

The operation of the apparatus Will now be clear. With the conveyor belt in motion, travelling in the direction of the arrow from beneath the bin 34, it will carry on its upper surface a relatively deep layer 35 of the cementitious mixture. `This is reduced to the desired thickness (usually in making shingles, e. g. to 1/1 or 1/2 inch more or less) by lthe revolving brush 36. The level layer 35 thus formed is then carried along, successively passing beneath the depositing elements of the apparatus 1, 2, 3 and 4. Obviously a less number of depositors may be employed, or only one, or more than 4, as desired.

The hopper of unit 1 is now filled with crushed granular material such as crushed red slate, for example, while the hopper of the second unit 2 may be filled with crushed black slate, hopper 3 with more of the red slate, and the fourth hopper with crushed yellow slate. Pulley 9 is then driven by connecting with a suitable source of power, l

whereupon through connecting sprocket chains 8 each of the spiral worms 10 is revolved within its respective hollow tube 11, and carries the crushed slate from the bottom of the hopper 6 longitudinally of the hollow 3 tube 11 and over the helical slit which is provided in the bottom thereof, through which it falls into the cylinder 7. The cylinder 7 is rotated by pulley 9 through chain drive 8 and accordingly tumbles the granular material through the openings 22, 22 as they successively reach the bottom position and discharges the same therethrough in quantities depending upon the width of the undernlost aperture, the speed of revolution, the size of the granule, the size of the screen, the rate and quantity of feed, etc. The material is thus discharged throughout the length of the cylinder in patches and amounts according to the size and width of the opening.`l

along the lowermost line of the cylinder at any given instant. As the cylinder rotatesV the sizes and areas of such patches are constantly changing. The material discharged falls upon baies 24, 25 which may be fixed or vibrated. If these are to be vibrated, th

toothed wheel 31 is caused to be rotated by pulley 9 and brought into engagement with the lug 29 on rod 28. This is vibrated longitudinally, against the resiliency of the vibrator springs 27 which, upon release of the teeth of wheel 31, repeatedly return the rod to its initial position. As the vibrator springs29 are thus given a rapid back and forth motion, they transmit the saine to the baiiie plates 24, thus bouncing the granular material falling upon them and still further scattering and rendering the distribution of the same more irregular, as it falls upon the sheet of cement-asbestos mixture passing beneath it. As the sheet .continues under the following units 2, 3 and 4 it receives successive applications of like deposits of irregularly disposed granules of different colors, black, red, yellow and finally passes beneath a second compression roller 37 and a stream of water at 38. It is then cut into separate shingles by the revolving blade 39, as desired.

The shingles are then allowed to dry slowly to permit the cementitious bond to thoroughly set, which thereupon adheres to the granular particles of slate, (thoroughly seated therein) and permanently retains them in place. The grains of different .colors stand out prominently and are not mingled with each other, which is commonly the result obtained by other methods and other types of apparatus. Moreover, such colored areas are irregularly disposed over the treated surface not only with respect to patches of the same color but also with respect to patches ofthe several colors, so that repetition of patterns is substantially ycompletely avoided. If such repetition should occur, it is only at such in requent intervals as to be practically negligible and not detectable in the final product, even after regular and extended runs of manufacture upon a commercial scale.

Variations in operation may also be introduced, if desired, still further to vary the e]ection and deposition of granular material, such as the speeds of rotation of the cylinder and worm, rate of feed of the granular material to the hopper, the sizes of granular material used, speedy of the conveyor, and replacement of the cylinders 7 by other cylinders or alteration of the apertures therein. The manner of effecting such variations in practice will -be obvious from the drawings of the apparatus described or by the adaptation of known expedients therefor. The more haphazard and imperfect such adjustments and variations are permitted to be the more variegated will be the irregularitypf pattern produced in the finished product.

Due to initial crushing of the stone or other substances which may be employed for the purpose, the granular material will ordinarily contain grains of various sizes and shapes. To promote the effects desired, it is usually preferable not to segregate such differentsizes of grains because this would have a tendenc toward regularity of pattern and also wo d involve an uneconomical use of the granular material. By the present process, granules of such ranges of sizes are applied to the surface in the proportions iii which they originally occur, without segregation or separation in the course of the distributing operation.

Again, local piling of the granular matcrial, resulting in concentrated piles in some areas and bare portions iii other parts of the sheet are effectively avoided. Bare portions may be in some respects desirable, and may be attained in those cases by the present process, as by using a single distributing element only, but excessive piling may prevent complete peiietration of all of the granulesof such piles into the sheet upon compression and hence the surplus is wasted, while the lower portions of the pile may be caused to penetrate the sheet too deeply and cause weakening.

Shingles, or other cementitious surfaces treated in accordance with the invention, as indicated by'Fig. 5, present a pleasing ir regularly colored effect, the several colors grading sharply each into the other with a small proportion of intermediate shades of relative light and shadow, the patches of unitary color standing out, as high lights in the general surface when viewed as a whole, but without perceptible repetition through extensive areas.

It will be obvious to those skilled in the art of making plastic and like cementitious products, that the invention is susceptible of a wide and varied application to numerous objects, where like results to those described are to be sought, either for aesthetic or for utilitarian purposes of quite other character. Such modifications and applications are, however, to be considered as contemplated by the above disclosure and included within the scope of the following claims.

I claim: l

1. Inapparatus for applying granular material to the surface of sheet material, the combination of a conveyor for the sheet material, delivering means located above'the sheet material at a distance therefrom permitting free fall of granular material, to let `fall said granular material intermittently in successively varying quantities and fr om successively different locations, upon said sheet material, and means in the path of lfalling granular material to arrest temporarily and distribute the same during its descent to the sheet material.

2. In apparatus for applying granular material to the surface of sheet material, the combination of a conveyorfor the sheet material, delivering means located above the sheet material at a distance therefrom permitting free fall of granular material, to let fall said granular material intermittently in successively varying quantities and from successively difercut locations. upon said sheet material, a baffle in the path of falling granular material to arrest temporarily and distribute the same during its descent to the sheet material.

3. In apparatus for applying granular material to the surface of sheet material, the combination of a conveyor for the sheet material, delivering means located above the .sheet material at a distance therefrom permitting free fall of granular material, to let fall said granular material intermittently in successively varying quantities and from successively different locations, upon said sheet material, a battle in the path of falling granular material to arrest temporarily and distribute the same during its descent to the sheet material, and means for intermittently vibrating said baiie.

4. In apparatus for applying granular material. to the surface of sheet material, the combination of a conveyor for the sheet material, a delivering drum, perforated irregularly, located above the sheet material at a distance therefrom permitting free fall of granular material, to let fall said granular material intermittently in successively varying quantities and from successively different locations, upon said sheet material.

5. In apparatus for applying granular material to the surface of sheet material, the combination of a conveyor for the sheet material, a plurality of delivering means located in lines along and above the sheet material at a distance therefrom permitting free fall of granular material, each adapted to let fall said granular material intermittently in successively varying quantities and from successively different locations upon said sheet material, said delivering means differing from one another in respect to the quantitative and positional variations in delivery of said material.

6. In apparatus for applying granular material to the surface of sheet material, the combination of a conveyor for the sheet material, a plurality of delivering drums located in lines along and above the sheet material at a distance therefrom permitting free fall of granular material, each drum perforated irregularly to let fall said granular material intermittently in successively varying quantities and from successively different locations upon said sheet material, said delivering drums differing from one another in respect to the arrangement and location of these perforations.

7. In apparatus for applying granular material to the surface of the sheet material, the

combination of a conveyor for the Sheet material, a plurality of delivering means located in lines along and above the sheet material at a distance therefrom permitting free fall of granular material, each adapted to let fall said granular material intermittently in successively varying quantities and from suc-

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