US2370393A - Method and apparatus for making wallboard - Google Patents

Description

METHOD AND APPARATUS FOR MAKING WALLBOARD Filed Feb. 11 1942 5 Sheets-Sheet 1 a I I hu w Feb. 27, 19 5- wfe. BRUBACHER METHOD AND APPARATUS FOR MAKING WALLBOARD 3 Sheets-Sheet 2 Filed Feb. 11, 1942 w hm hm i A IRANNPNRAE WM Q F 1M Q Q I @g x H H m 8. mm Nvm om MM WW m fl hm b H mm a g H WINK Feb. 27, 1945.

w. G. BRUBACHER 2,370,393 METHOD AND APPARATUS FOR MAKING WALLBOARD Filed Feb. 11, 1942 3 Sheets-Sheet 3 Patented Feb. 27, 1945 METHOD AND APPARATUS FOR WALLBOARD William G. Brubacher, Montreal, Quebec, Canada 1' Application February 11, 1942, Serial No. 430,422

12 Claims.

This invention relates to a method and apparatus for making wall board and the like.

Wall board has been made for many years with fibrous material of difierent types, for example, from wood fiber, sugar cane fiber, etc. Boards of this type possess a very low degree of structural strength and may be surfaced only at substantial expense and with difficulty. The reason for this is that the material from which the board is made is distributed throughout the body of the board with almost perfect uniformity, as the result of which both surfaces of the board contain a substantial proportion of relatively long coarse fibers, thus making it difficult to provide the board with a smooth surface.

An important object of the present invention is to provide a novel method of making wall board from fibrous material wherein the finished board has the portion adjacent one surface thereof formed entirely of very short fibers, thus renderin such surface of the board quite smooth without the necessity for performing additional operations thereon.

A further object is to provide a method where'- in the portion of the board adjacent the opposite surface is made up very largely of interlocked relatively long coarse fibers with a very small proportion of shorter fibers therein, whereby the resultant board possesses substantially greater structural strength than boards made of similar materials of equal volume produced in accordance with prior methods.

A further object is to provide a method of mak ing wall board of the character referred to wherein the method operates continuously to provide a finished board structure having openings therethrough whereby the finished board is materially thicker than boards produced with prior methods and containing the same amount of material, and wherein the finished board possesses an unusually high degree of heat insulating value.

A further object is to provide a novel type of apparatus for producin wall board of the character referred to, wherein the apparatus operates continuously to produce the board.

A further object is to provide novel means for feeding the fiber-containing pulp to the inlet end of the apparatus in such a manner as to automatically control the distribution of fibers in the resultant board so that one side of the board contains largely long coarse fibers while the other side of the board is made up entirely of short fibers to produce a smooth face at such side of the board.

A further object is to provide novel means in the' apparatus for continuously producing a wall board having openingsf of substantialsize-extending through the length of the board to'increase the insulating value of the board and to produce a board of greater thickness with the same volume of material per unit of length, and

A further object is to provide an apparatus of the character referred to wherein'the elements which form the openings through thelength of the board are positively supported at -oneg'end, and have their opposite "end portions supported by the material of the'board itself duringformation thereof, the forming of the bottom portion of the board with longer coarser fibers-rendering more efficient thesupporting in such manner of the elements which form the openings.

A further object is to provide novel means in association withth'e board forming mechanism for efiecting a separation of the fibers and the distribution of the fibers to the board forming mechanism in such a manner that the top.portion of the board will be made up wholly of material containing short fibers whereas the bottom of the board, beneath the opening forming elements, will be made up largely of longer coarser fibers.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawings I have shown one form of apparatus particularly adapted for practicing the method. In this shoWing- Figure 1 is a side elevation of the apparatus,

Figure 2 is a central vertical longitudinal sectional view through the apparatus,

Figure 3 is a transverse vertical sectional=vlew on line 3-3 of Figure 1,

Figure 4 is a similar view on line 4-4 of-Figure 1,

Figure 5 is an enlarged detail perspective view of one of the forming tubes, a' portion being broken away, I j r Figure 6 is an enlarged transverse sectional view on line 6-6 ot'Figure'5, I

Figure '7 is an enlarged fragmentary detail sectional view of one of the deckel supporting pulleys and associated elements, parts being shown in elevation,

Figure 8 is a section on line 8-8 of Figure 7,

Figure 9 is a detail perspective of a portion of a wall board produced in accordance with the present invention, and,

Figure 10 is a sectional view through a portion of a wall showing the wall board attached thereto.

Referring to the drawings it will be noted that the present apparatus is generally similar in construction to a conventional Fourdrinier paper machine, although the apparatus has been altered and additions have been made thereto which makes it, in effect, a diiierent apparatus adapted to make the novel wall board in accordance with the present invention, which cannot be done on a conventional Fourdrinier'machine. The apparatus may be provided with two main supporting frames II and II respectively comprising side frame members 12 (Figure 4) and I3 (Figure 3) and between the side frame members are rotatably supported a series of table rolls l4 over which passes the upper run i5 01 an endless wire indicated as a whole by the numeral I. At the forward end or the apparatus the wire passes around a breast roll I], while at the rear or outlet end of the apparatus the wire passes around a couch roll I 8. The lower run I! of the wire passesbeneath a stretch roll and over a guide roll 2|, as shown in Figures 1 and 2. The stretch roll 24 is supported for rotation by upstanding members 22 which may be formed inteflral with the side frame members I3 and the stretch roll may bevertically adjusted by rotation of screws 23 connectedto the bearings 24 of the stretch roll. The guide roll 21 may be supported by depending bracket arms 25 carried by the side frame members l2, and the guide roll is longitudinally adjustable by screws 24 connected to the bearings 21 of the guide roll. The adjusting means for the rolls "and 2| are conventional and form no part per se of the present invention.

Between the breast roll I1 and the first table roll l4 the apparatus is provided with a pair of suction boxes 28 the surfaces of the top edges of which are arranged in a common plane with the upper limits oi. the breast roll H and table rolls l4 so that the upper run l5 oi the wire passes directly over these suction boxes so that a substantial amount of water will be constantly taken from the pulp mass through the wire in a manner-to be described. Each suction box 28 is provided with a downwardly extending drain pipe 2! controlled by a valve 30, and the lower ends or the pipes are connected with a drain trough 3|, or with suitable conventional suction creating means, depending upon whether it is desired to permit water to drain by gravity from the mass passing over the boxes 25, or to induce a drainage of water from the mass. The trough 3i may be arranged in a pit I2 suitably connected with a sewer.

The last table roll l4 toward the outlet end of the apparatus that is, the right hand end as viewed in Figure 2, serves as a squeeze roll in a manner to be described, and isseparated from the next table roll I4 to provide a space for a plurality oi suction boxes I! each of which is provided with a drain pipe 34 leading to a manifold pipe 35- (Figure 1), and the latter pipe may be suitably connected in the usual manner to suction creating means similar to that employed for a conventional Fourdrinier machine. Each pipe 34 may be controlled by a valve 36.

It will become apparent that the watery pulp mass is led to the top wire in a novel manner quite distinct from the methods employed with a Fourdrinier machine. Referring to Figure 2 the numeral 31 designates a control box having one end wall and the two side walls 38 having their lower edges in a common plane substantially contacting the top run l5 of the wire, and a partial bottom wall 40 (Figure 2) extends from the wall 38 to a point adjacent the beginning of the top run [5 of the wire. The other end wall 4| of the control box has its lower portion curved outwardly from the box as at 42 (Figure 2) and terminating a substantial distance above the top run l5 of the wire. The distance between the lower extremity of the wall 4| and the top run l5 of the wire determines the thickness of the feed of the mass to the wire, as will become apparent.

Spaced walls 43 and 44 extend transversely across the box 31 to divide the latter into three compartments 45, 46 and 41, for a purpose to be described. The lower edges of the partitions 43 and 44 terminate a substantial distance above the top run l5 of the wire as clearly shown in Figure 2. The feeding of material into the compartments 45, 4B and 41 is determined by the operation of a pulp screen indicated as a whole by the numeral 48. This screen is provided with upstanding imperforate walls 49 to the bottom of which is connected a screen element 50 having slots cut therethrough for the passage of the pulp. The slits 5| in the screen 50 over the compartment 41 are of such size as to permit only the smallest shortest fibers to pass therethrough while the slits 52 over the compartment 48 are of such size as to permit fibers up to a medium size to pass into the compartment 46. The slits 53 over the compartment 45 are of such size as to permit the passage therethrough of any fibers up to the largest size. It will be apparent, therefore, that the finest fibers can pass through any portions of the screen; that nothing larger than medium sized fibers can pass through the slits 52; and that any of the fibers can pass through the slits 53. Since the largest fibers can pass solely through the slits 53 it will be apparent that the fibers passing into the compartment 45 will be predominantly the largest coarsest fibers. Similarly, only medium and fine fibers can pass into the compartment 46, while only the finest fibers can pass into the compartment 41. This control of fiber size is important in the production of the wall board contemplated by the present invention.

The screen 48 is suspended by spring steel element 54 connected at their upper ends to supporting elements 55 carried by an overhead support 56. While it is not necessary to vibrate the screen 48, such operation is preferred and for this reason a constantly driven shaft 51 is provided with an eccentric 58 operating in a strap 59. The latter element is connected by an arm 50 to a pivot pin 6| carried by the adjacent wall of the screen 48 and accordingly it will be apparent that the screen is constantly vibrating during the operation of the apparatus. Pulp may be fed to the screen in any suitable manner, for example, from a stock inlet hopper 62, and the watery pulp mass in the screen 48 may be kept thoroughly agitated by a stream of water flowing thereinto through a nozzle 63.

The stock is fed to the top run l5 of the wire very much thicker than is true in a conventional Fourdrinier machine, and it will be obvious that a conventional deckel strap employed for confining the pulp mass on the wire cannot be employed with the present invention. In Figures 1, '7 and 8 I have illustrated a novel type of deckel which is particularly adapted for use with the present apparatus. Vertical pulleys B4, 65 and 66 (the latter of which is shown in detail in Figure 7 and 8) are supported on shafts 51 rotatable in bearings carried by depressed supporting frame elements 88 forming portions of the opposite frame members I2. A suitable form of bearing for each of the shafts 81 (except as will be referred to) is shown in Figure '1. Each pulley may have at its lower end a hub 69 fixed to the associated shaft by a set screw 18 and the lower end of the shaft is mounted in a bearing H and supported by a thrust bearing 12. The bearing so far described is all that is necessary for the shafts of the pulleys 84 and 65, the set screws 18 roviding for vertical adjustment of each associated pulley 64 or 65, which is the only adjustment necessary for such pulleys. The bearing for the shaft of the pulley 86 is preferably provided with horizontal take-up means in which case the bearing H is provided with a flange 13 slidable in guides 14. The end of the flange 13 remote from the other pulleys i provided with an upstanding lug 15 received between collars 16 secured to an adjusting screw 11 provided with a head 18 and threaded through aing 19 carried by the corresponding supporting frame element B8.

A deckel unit indicated as a whole by the numeral 88 passes around the pulleys 64, 65 and 66 and each of the pulleys is provided at its ends with outstanding flanges 8| so as to properly vertically position the deckel unit for a reason which will become apparent. The deckel unit comprises a flexible belt 82 preferably perforated as at 83 and a screen 84 (Figure 8) is coextensive with and secured against the outer face of the belt 82. Each of the deckel supporting pulleys is arranged in close proximity to the adjacent edge of the to run I of the screen I6, as shown in Figure 8. The lower flange 8I of each pulley is disposed just below the adjacent edge of the top run I5 of the screen and the lower edge of the belt 82 obviously will be supported on the lower flanges 8| of the pulleys. The face of the inner run of the belt 82 adjacent the edge of the screen I5 will barely clear the screen,,and accordingly the lower edge of the deckel screen 84 will overlie the adjacent edge of the top run of the screen I6. This arrangement is shown in Figure 8. The deckel arrangement adequately confines the thick mass of pulp upon the top run of the screen I8 and assists in draining water therefrom, due to the use of the screen 84 and perforated belt 82, while at the same time the deckel arrangement does not interfere with or cause wear upon the screen I8. It will be obvious that one of the deckel units is arranged at each side of the apparatus, as will be clear from Figures 3 and 4.

The deckel pulleys 63 and 64 are positively driven by the means shown in Figures 1, 2, 4, 7 and 8. At each side of the apparatus is arranged a pair of bearings 86 and 81 the former of which is arranged adjacent the corresponding pulley 66 between opposite runs of the belt 82. The bearing 81 may be arranged to the left; as viewed in Figure 1, of the corresponding pulley 84, and both bearings may be supported by suitable portions of the side frame members I2. A shaft 88 is rotatably supported in the bearings 86 and 81 at each side of the apparatus and carries bevel gears '89 and 88 respectively meshing with bevel gears 9| and 92 carried by the upper ends of the shafts 61 of the respective pulleys 64 and 68. Each bevel gear 98 is splined as at 93 .on the shaft 88 so as to slide on the shaft in accordance with horizontal adjustments of the associated .pulleys 86.

Each bevel gear 98 is maintained in mesh with its associated gear 92 by a bearing bracket 94 having its ends respectively surrounding the shaft 88 and the shaft 81 of the associated pulleys 68 (Figure '1).

Adjacent the inlet end of the apparatus is arranged a supporting frame structure indicated as a whole by the numeral 95 and extending transversely of the apparatus. This frame structure carries a pair of upstanding bearings 96, one for each of the, shafts 88. Each of these shafts carries a pulley 91 around which passes a belt 98. The upper end of each belt 98 passes around a pulley 99 mounted on an overhead drive shaft I88 as shown in Figures 1 and 2. The shaft I88 carries a pulley I8I around which passes a drive belt I82 and this belt drivesa pulley I83 on the drive shaft 51 for the eccentric 58. The latter shaft may be supported in any suitable manner, for example, on the upper end of a frame I84.

The wall board is continuously formed on the upper run I5 of the wire I8, as will become apparent, and in the formation of the board, openings are formed extending longitudinally of the board. For the purpose of forming these openings a plurality of tubular formers, each indicated by the numeral I85, is employed. One of the tubes is shown in detail in Figures 5 and 6 and one of the tubes is shown in position in Figure 2 in the wall board being formed. with the apparatus. Each tube I85 is of uniform cross-' scribed. Each tube is preferably provided with a number of radial openings I81 the purpose of which also will be described later. At its left hand end as viewed in Figures 2 and 5, each tube I85 is provided with a pulley I88 around which passes a driving belt I89 and these belts are driven from a shaft II8 by one or more pulleys III. In other words, a separate pulle may be mounted on the shaft IIII for each of the belts I89 or a single elongated pulley may be employed, as will be obvious. One end of the shaft III) is provided with a driving pulley II2 which may be driven from any suitable source of power.

Each of the tubes I85is supported in a bearing II3 (Figure 2) carried by the wall 38 of the box 31 (Figure 2) and outwardly of such box each tube is also supported in a bearing II4 carried by the supporting structure'95. It will be apparent that from its bearing II3 (Figure 2) to its extreme right hand end each tube is entirely free, there being no bearings other than those described. In the operation of the apparatus, as will become apparent, each of the tube .will be supported throughout most of grooves I86 are cut in such a direction with rela-.

tion to the direction of rotation of the tube and with relation to the speed of rotation of the tube as to tend to feed the pulp material horizontally at a linear speed corresponding to that of the upper run I5 of the screen I8.

In addition to being wholly unsupported vertically from th bearings II3 to their free ends, the tubes I85 are likewise obviously unsupported to support the tube against horizontal displacement. Means is provided to position the tubes horizontally without interfering with the continuous formation of the board. Referring to Figures 1, 2 and 4 the numeral II5 designates each of a plurality of spider structures each of which comprises a hub IIG having pairs of radial arm's II1 the outer ends of which turn as at H8 awa from the direction of rotation. In other words, each spider structure, as viewed in Figure 2, turns in a counterclockwise direction and the ends II8 are turned in a clockwise direction; The spaces between the arms II1 of each pair are approximately equal to the diameter of each tube I05 so as to receive one of these tubes therebetween. Moreover, the arms I I1 are of such number and length that each successive pair of ends I I8 will assume a position straddling its associated tube I05 before the preceding pair of ends II8 has moved above the associated tube I05. Thus there will always be at least one pair of arms I I1 or their ends I I8 in a position to prevent lateral displacement of each tube I05.

The hubs II5 are mounted on a transverse shaft II8 provided at one end with a pulley I adapted to be driven from any suitable source of power. The shaft H8 is driven preferably at such speed that the peripheral speed of the ends II8 will approximate the linear speed of the top run I5 of the wire I5. Of course, this linear speed of the ends H8 is circumferential and corresponds to the horizontal speed of the upper run I5 of the wire only at the instant when each end H8 is directly beneath the shaft H9. The difference in horizontal speed of the ends II 8 at other points while they are in the body of the board does not affect the operation of the apparatus, however, and the depressions formed by the arms H1 and their end-s II8 close as the board moves toward the right as viewed in Figure 2 due to the reasonabl soft condition of the board at such point.

By the time the board has passed the right hand end of the deckel units as viewed in Figures l and 2 the board will have set sufficiently to be self supporting against sagging at the edges. Beyond the deckel the semi-formed board extends beneath the lower run I2I of a top wire I22 which may be identical in a conventional top wire of a Fourdrinier machine. associated elements therefore need not be referred to in detail. The wire passes around end rolls I23 and I24 and thence over a top roll I25 and down toward the roll I23, over an intermediate roll I25. The roll I4 adjacent the roll I8 cooperates with a similar upper roll I21 to form a pair of squeeze rolls between which the wall board passes after moving a substantial distance between the upper and lower wires. These squeeze rolls definitely determine the final thickness of the board.

A section of the board is shown in Figure 9, the board being indicated as a whole by the numeral I28. Th board when passing from the machine in substantially finished form will be cut in suitable lengths by any desired means and the finished individual boards will have openings I29 extending throughout the length of the board. While the finished board will not in fact show sharply defined layers there will be structural differences in various parts of the board through the thickness thereof. For example, in the lower portion I30 of the board as viewed in Figure 9, the board will be made up largely of large relatively coarse fibers while the central This wire and its 5 portion I3I of the board through the thickness thereof will be made up largely of fibers of medium size. The top portion I32 of the board will be made up completely of relatively fine fibers which will permit the board to take a relatively fiat smooth finish to adapt it for surface decorations of any desired type.

The openings I28 in the board serve several functions. In the first place, they increase the insulating value of the board materially, and in the second place, aside from their presence as dead air spaces, they provide for a much thicker board from the same amount of pulp stock. Additionally, the openings I29 serve to assist in fastening the wall board in' position. For example, each opening I29 may have driven thereinto wood blocks I33 (Figure 10) which may be forced in by metal rods calibrated so as to permit the spacing of the blocks at desired intervals. These wood blocks may receive screws driven through the board from the outer side of the structure of which the board I28 is a part. For example, the board is shown in Figure 10, for the purpose of illustration, as lying against corrugated sheet metal I34 and a screw I35 is shown as being driven through the corrugated metal into the board at such a point as to engage one of the blocks I33. Thus it will be apparent that it is possible in some structures to secure the wall board firmly in position without driving fastening elements through the inner surface of the wall board.

The operation of the apparatus is as follows:

The thin watery pulp is fed to the hopper 82, as will be obvious, to be supplied to the screen 48. As previously stated this screen is preferably vibrated by rotation of the shaft 51 and eccentric 58, thus assisting in maintaining a uniform mixture of the fibers of the pulp in the screen. Water is fed into the screen through the nozzle 63 and performs the same function as the eccentric mechanism in that it tends to stir and agitate the fibers. Both of the means referred to are preferably employed since it is desirable to keep the pulp in motion in the screen.

The openings 5| are of such size as to permit the passage therethrough of only the smallest fibers, and such fibers pass through the openings into the compartment 41. The openings 52 are of such size as to permit nothing larger than medium sized fibers, and accordingly fibers of such size and smaller will pass downwardly into the compartment 46. The largest fibers can pass through the openings 53 into the compartment 45 and since fibers of this size cannot pass through either the openings 5I or 52, all of the large fibers will find their way into the compartment 45.

The upper run of the screen I6 moves constantly toward the right as viewed in Figure 2 and this motion constantly withdraws material from the hoppers 45, 46 and 41, the material moving toward the right to make up the finished wall board as will become obvious. The separation of the fibers by the screen 50, acting as a classifier because of the difference in the sizes of the openings SI, 52 and 53, results in somewhat stratifying the fibers by the time they pass under the lower edge of the wall M. It is not strictly true, of course, that definite stratification takes place since there will be a mixture of fine and medium sized fibers in the compartment 46 and a mixture of fibers of all sizes in the compartment 45. However, only the finest fibers will be in the compartment 41 while all of the coarse fibers will be in the compartment 45. There will be a graduation of the fibers through the thickness of the mass as it passes beneath the bottom of the wall 44, the finest fibers stay ing at the top of the mass as they pass from the compartment 41, the medium and fine fibers stayin in the center of the mass from top to bottom as they pass from the compartment 46 and the coarsest fibers remaining at the bottom of the mass as they pass from the compartment 45.

As previously stated the pulp is fed to and through the screen 50 in a thin watery mass, a

- substantial amount of water being used to permit a constant thorough mixture of the fibers for the purpose of facilitating their partial classification as stated. Water in the mass between the walls 38 and M flows downwardly relatively readily and will pass through the top run I of the screen, the majority of the water being taken up by the suction boxes 28. While these boxes are shown as feedingwater downwardly by gravity into the trough 3|, it will be obvious that positive suction means may be connected to the pipes 29 in accordance with conventional practice.

As the mass passes beneath the lower edge of the wall 4| it will be apparent that the majorit of water will have been drained from the mass although the latter is still in. such a loose generally plastic condition as not to be self, formretaining. It is forthis reason that the deckels 80 are provided. The mass will be prevented from spreading laterally on the top run I5 of the screen by proximity of the screen to each of the deckel screens 84 and each of these screens. backed up by the perforated belt 82, permits the passage of water from the edge portions of the screen. This operation facilitates and hastens the setting of the edge portions of the mass so. as to render itself form-retaining by the time the mass passes beyond the deckels.

It will be apparent that the foregoing motion of the mass from the compartment 45, 46 and 41 takes place around the tubes I05. These tubes are spiralled as shown in Figures 2 and 5 with the spirals turning in the correct direction and at the correct pitch with relation to the direction and speed of rotation of each tube as to cause the spiral grooves to tend tomove the mass at a linear speed corresponding to that of the upper run I5 of the screen. The relatively wet condition of the mass permits it to move freely with respect to the surface of each tube and the rotation of each tube prevents any adhesion of the mass thereto.

Thus the mass continues to move over the upper run I5 of the screen I6 with the tubes I05 embedded directly in the mass and as the material of the mass sets, openings will be formed therein corresponding in shape and size to the tubes I05. After leaving the deckels the mass will be only slightly thicker than the desired thickness of the resultant wall board and the mass passes beneath the bottom run I2I of the top wire I22. This wire tends to slightly compact the mass to assist in compressing water therefrom and the suction boxes 33 are provided to assist in taking from the mass as much Water as possible prior to its exit from the machine. Before leaving the machine the board passes between the roll I4 adjacent the right hand end of the apparatus (Figure 2) and the roll I21, these rolls acting as squeeze rolls to reduce the mass to the final board thickness.

The tubes I05 extend to the limit of the outlet end of the apparatus and the board passing from the ends of the tube will retain the openings I29 (Figure 9) therein since at the outlet end of the apparatus the board will be wholly self form-retaining. Any suitable means may be employed for carrying off the continuously formed board and for periodically cutting the board transversely into individual pieces of the desired length.

As previously stated the tubes I05 are not provided with any positive supporting means from the bearings II3 (Figure 2) to the outlet end of the apparatus. When the apparatus is initially placed in operation suitable means may be employed, if desired, for initially supporting the free ends of the tubes I05. During the continuous operation of the apparatus, however, it will be obvious that the tubes will be in contact with the pulp material forming the bottom portion of the board and each tube is therefore in engagement with a supporting surface throughout its length. The ability of the material of the board to support the tubes is increased and rendered more positive by the fact that the bottom portion of the board is made predominately of the largest fibers in the mass. This fact renders the bottom of the board relatively structurally of substantial strength which is desirable in order to pro vide adequate support for the tube I05. In addition, this structural strength improves the general quality of the board and renders it easier to permanently attach the resultant boards to a supportin surface or structure with less danger of any pulling out of the fastening elements occurring.

The bottom of the resultant board will be relatively rough but of substantial strength as stated, and such surface of the board is placed against the supporting surface or'structure to which the individual boards are to be attached. The top surface of the board will be made up completely of the finest fibers in the mass, thus providing a top surface portion which is capable of being very smoothly surfaced, which is not possible with ordinary boards of this type wherein there is a relatively unform distribution of fibers of different sizes with as many long coarse fibers forming one surface of the board as the other. The resultant board, therefore, possesses substantial inherent strength while at the same time providing a final surface with an extremely smooth texture particularly adapted for receiving surface coating or ornamentation of any desired type. The provision of the openings I29 improves the heat insulating value of the board by providing a thicker board for a given quantity of material per unit of size, and by providing dead air spaces in the board.

The use of the spiders H5 is not essential but is preferred. During the making of the board the tubes I 05 are adequately supported by resting on the bottom portion of the mass from which the board is formed. This mass does not fixedly prevent lateral movement of the tubes I 05, which is possible due to their resilience incident to their diameter in proportion to their length. On the other hand, there is less tendency for the tubes to move laterally since there is no force present tending to cause such movement as is true of vertical movement, the force of gravity tending to move the tube downwardly. To positively anchor the tubes in definite positions, however, the spiders lI5 are preferably used and their operation was set forth above in connection with the description of their structure. The aims of the spider of each pair conline one of the tubes therebetween and a pair of spider arms are always in a position to positively prevent lateral movement of each tube.

It will be obvious that a number of the structural features of the apparatus have been only generally illustrated. For example, any suitable means may be employed, other than the means shown and described, for rotating the tubes Ill-5 and the same is true of the specific means for driving the deckels. In connection with the latter elements it is particularly noted that the deckels of the present apparatus depart substantially from Fourdrinier practice in that they are much wider and are quite different in structure. Each deckel belt may be exactly vertically positioned by loosenin the lock screw I of each deckel pulley and moving the pulley vertically on its associated shaft to exactly position the wire 84 of each deckel (Figure 8) so that its lower edge barely clears the adjacent upper surface of the edge portion of the top run I of the belt It. With the mechanism so adjusted the flanges 8| at the bottoms of the deckel pulleys will adequately carry the load of the deckel, while the flanges 8| will be arranged beneath the edge of the adjacent edge of the screen I6 to clear this screen and accordingly avoid any wear thereon. Each deckel may be suitably tightened by adjustment of the screw 11 (Figure 7) as will be obvious.

As previously stated the elements I05 are tubular and are perforated as at I01. While it is not essential, it will be apparent that these tubes are of substantial value for purposes other than those described in that they may be used as means for injecting into the board any desired fluid for any desired purpose. For example, air may be blown through the tubes and out through the perforations III! to positively prevent any adhesion of the mass to the tubes, or any desired gases or chemicals may be forced through the tubes and through the openings IIII to effect a strengthening of the resultant board, or for any other purpose.

The resultant board may be freely used wherever a wall board of this general type has been previously employed, but with improved results. The board possesses substantial structural strength to permit it to be permanently attached wherever desired, and the board possesses a high degree of heat insulating value. As suggested in Figure 10 wood blocks I33 may be forced into the openings I29 to remain therein at spaced intervals to serve as means for more positively securing the wall boards in position. For examplc. the wall board may besecured directly against a corrugated metal structure I34 and screws I35 may be passed through the metal structure to engage in the wood blocks I33, thus fastening the boards in position from the outside and completely eliminating any marks on the inner surface of the board incident to the use of fastening elements commonly employed.

From the foregoing it will be apparent that the present invention contemplates a method of making wall board from fibrous material wherein there is a relative separation of the fibers and a subsequent bringing together of the fibers in a predetermined relatively stratified relationship whereby one surface of the resultant board will be made up of relatively coarse interlocked fibers to present a wall board of increased strength. The method also contemplates the placing together of the fibers in such relationship that the other surface of the board will be made up solely of line fibers so as to permit the making of a resultant board having one very smooth face particularly adapted for receiving surface coatings. ornamentations or the like. Moreover, the present method contemplates the continuous formation of wall board material by the feeding of fibrous material in such a manner that forming elements remain wholly within the limits of the mass while the board is being formed, thus providing a resultant board having openings therethrough. In accordance with such feature of the method a resultant board of a given width and length may be'made substantially thicker with the same amount of material and the resultant board will possess heat insulating characteristics superior to previous wall board structures because of such increased thickness and because of the formation of the openings parallel to the surfaces of the board.

While I have described in detail the preferred practice of my process and a preferred form of apparatus with which it is to be used, it is to be understood that the form of apparatus and the details of procedure of the process may be widely varied without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. The method of making relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom, which comprises moving a mass of the mix in a given direction with an elongated forming element submerged therein and extending in such direction and fixed against longitudinal movement, and progressively removing liquid from the mass to cause the mass to set during its travel in said direction until it is self formretaining when it leaves said forming element.

whereby the resultant board will be provided with an opening extending therethrough corresponding in shape and size to the cross-sectional shape and size of the forming element.

2. The method of making relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom, which comprises moving a mass of the mix in a given direction with an elongated forming element submerged therein and extending in such direction and fixed against longitudinal movement, progressively removing liquid from the mass to cause the mass to set during its travel in said direction until it is self form-retaining when it leaves said forming element, whereby the resultant board will be provided with an opening extending therethrough corresponding in shape and size to the cross-sectional shape and size of the forming element, and continuously rotating said forming element to assist in preventing adhesion thereto of the material on said screen.

3. The method of making relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom, which comprises moving a mass of the mix in a given direction with an elongated forming element submerged therein and extending in such direction and fixed against longitudinal movement, progressively removing liquid from the mass to cause the mass to set during its travel in said direction until it is self form-retaining when it leaves said forming element, whereby the resultant board will be provided with an Opening extending therethrough corresponding in shape and size to the cross-sectional shape and size of the forming element, and feeding a fluid to the surfaces of the openings formed by the forming element during the movement of the mass with respect thereto. by pumping the fiuid through the forming element.

4. The method of forming relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom. which comprises subjecting a mass of the mix to a separating action to at least partially separate the mass according to sizes of the fibers therein, continuously feeding the respective mass-separations one behind another to a moving horizontal screen to superimpose them whereby the resultant board will have the portion adjacent one face thereof made up of fine fibers of the original mass and the portion adjacent the opposite face thereof made up predominantly of the coarse fibers of the original mass and whereby the liquid content of the mass will be progressively reduced by drainage of the liquid through the screen, and maintaining within the moving mass a forming element fixed against longitudinal movement and elongated in the direction of travel of the mass on the screen and of such length that the mass will have become self form-retaining before leaving the forming element. whereby the resultant board will be formed with an opening extending longitudinally therethrough corresponding in cross-sectional shape and size to the cross-sectional shape and size of the forming element.

5. An apparatus for forming relatively thick wall board or the like comprising a longitudinally movable horizontal supporting screen. means for supplying to on end of said screen a relatively thin watery mass of fiber-containing m x. parallel means projecting upwardly from opposite edges of said screen to maintain the mix thereon to a substantial depth until it becomes 'self form-retaining. a formin element projecting longitudinally of the screen and supported throughout the greater portion of its length by the material thereon whereby the mater al moves continuously from the end of said forming element, said forming element being of such length that the material on the screen will be self formretaining as it moves from said forming element to leave a resultant opening longitudinally throughout the resultant board, means for rotating said forming element to assist in preventing adhesion thereto of the material on said screen. said forming element being circular in cross-section and being provided with a spiral groove of such pitch with relation to the speed and direction of turning movement of the forming element as to tend to move the material o n the screen at the speed of movement of the screen.

6. An apparatus for forming relatively thick wall board or the like comprising a longitudinally movable horizontal supporting screen. mean for supplying to one end of said screen a relatively thin watery mass of fiber-containing mix. parallel means projecting upwardly from opposite edges of sa d screen to maintain the mix thereon to a substantial depth until it becomes self form-retaining, a forming element projecting longitudinally of the screen and supported through out the greater portion of its length by the material thereon whereby the material moves continuously from the end of said forming element. said forming element being of such length that the material on the screen w ll be self form-retaining as it moves from said forming element to leave a resultant opening longitudinally throughout the resultant board, said forming element being of tubular form and havin radial openings for the passage from the-interior of the tube of a fluid pumped into one end of the forming element.

'7. Apparatus for forming relatively thick wall board or the like comprising a longitudinally movable horizontal 'screen. means for supplying a relatively thin watery fiber-containing mix to said screen, a forming tube above and parallel to the screen and extending in the direction of travel thereof, means for supporting one end of said tube adjacent sa d end of said screen. said tube being supported throughout the greater portion of its length by the material on the screen whereby the latter is movable freely from the other end of the'tubr: in the form or" a board having an opening therethrough formed by said tube. and means for rotating said tube.

8. Apparatus for forming relatively thick wall board or the l ke comprising a long tudinally movable horzontal screen, mea s for supplying a relatively thin watery fiber-containing mix to said screen, a forming element extending over the wire n spaced relation thereto and extending in the direction of travel thereof. said forming element being positively supported solely adjacent sa'd end of the screen and supported throughout the greater portion of its length by the material on the screen to form a resultant board having an opening extending therethrough, and means for rotating said tube. said tube being provided with a spiral groove of such pitch with relation to the speed and direction of rotation of the tube as to tend to move the material on the screen in the direction and at the speed of movement thereof.

9. Apparatus for forming relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom. comprising a longitudinally movable horizontal supporting screen, means for progressively supplying the mix to one end of said screen whereb the mix travels with the screen and liquid drains from the mix through said screen. parallel means projecting upwardly from opposite edges of said screen to maintain the mix thereon to a substantial depth until it sets. a forming element projecting longitudinally of the screen and fixed against longitudinal movement, and means for supporting said forming element adjacent said end of said screen, the other end of said forming element projecting through the mix to be supported solely by the mix as the latter progressively sets. said forming element being of such length that the material on the screen will be self form-retaining as it continuously moves from the last named end of said forming element to leave a resultant opening Iongitudinally through the resultant board.

10. Apparatus for forming relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom. comprising a longitudinally movable horizontal supporting screen, means for progressively supplying the mix to one end of said screen whereby the mix travels with the screen and liquid drains from the mix through said screen. parallel means projecting upwardly from opposite edges of said screen to maintain the mix thereon to a substantial depth until it sets. a forming element projecting longitudinally of the screen and fixed against longitudinal movement. means for supporting said forming element ad jacent said end of said screen, the other end of said forming element projecting through the mix to be supported solely by the mix as the latter progressively sets, said forming element being of such length that the material on the screen will be self form-retaining as it continuously moves from the last named end of said forming element to leave a resultant opening longitudinally through the resultant board, and means for rotating said forming element to assist in preventing adhesion thereto of the material on said screen.

11. Apparatus for forming relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom, comprising a longitudinally movable horizontal screen, means for progressively supplying the mix to said screen adjacent one end thereof, and a forming element extending over the screen in spaced relation thereto in the direction of travel thereof and fixed against movement in such direction, said forming element being supported solely adjacent said end of the screen and being of such length to require support adjacent its other end in order to retain it in spaced relation throughout its length to said screen, said screen serving to drain liquid from the mix thereon so that the mix becomes self supporting before reaching the last named end of said forming element to form a resultant board having an opening extending therethrough and to serve as a support for the last named end of said forming element.

12. Apparatus for forming relatively thick wall board or the like from a thin watery fiber-containing mix which sets by the removal of liquid therefrom, comprising a longitudinally movable horizontal screen, means for progressively supplying the mix to said screen adjacent one end thereof, a forming element extending over the screen in spaced relation thereto in the direction of travel thereof and fixed against movement in such direction, said forming element being supported solely adjacent said end of the screen and being of such length to require support adjacent its other end in order to retain it in spaced relation throughout its length to said screen, said screen serving to drain liquid from the mix thereon so that the mix becomes self supporting before reaching the last named end of said forming element to form a resultant board having an opening extending therethrough and to serve as a support for the last named end of said forming element, and means for continuously rotating said forming element to assist in preventing adhesion thereto of the material on said screen.

WILLIAM G. BRUBACHER.

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