US2118491A

US2118491A - Paper making method and machine

Info

Publication number: US2118491A
Application number: US5201A
Authority: US
Inventors: Harry A Chuse
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-02-06
Filing date: 1935-02-06
Publication date: 1938-05-24
Anticipated expiration: 1955-05-24

Description

May 24, 1938.

H. A. CH USE PAPER MAKING METHOD AND MACHINE Fiied Feb. 6, 1955 6 Sheets-Sheet 1 May 24, 1938. H. A. CHUSE PAPER MAKING METHOD AND MACHINE Filed Feb. 6, 1955 6 Sheets-Sheet 2 mmx y H. A. CHUSE I 1 2,118,491

PAPER MAKING METHOD AND MACHINE Filed Feb. 6, 1935 s Sheets-Sheet 5 Inuerzln Harr CZ. Chase,

y 1938. H. A. CHUSE PAPER MAKING METHOD AND MACHINE Filed Feb. 6,

1955 6 Sheets-Sheet 4 @120"? 0/. Claws,

May 24, 1938. H. A. CHUSE 2,118,491

PAPER MAKING METHOD AND MACHINE Filed Feb. 6, 1935 6 Sheets-Sheet 5 y 70%11/70, )tu, album 9 i y,

May 24, 1938. H. A. CHUSE PAPER MAKING METHOD AND MACHINE Filed Feb. 6, 1935 6 Sheets-Sheet 6 I 22082225171 (Z. C/uw J- 111, W5

- Harry (1mm 7" Patented May 24, 1938 UNITED STATES PATENT OFFICE 6 Claims.

This invention, relating to paper making methods and machines, comprises improvements with reference to wetsheet formation, the whole process and means for making the wet paper sheet in the course of manufacture of paper in a continuous sheet, the construction and mode of operation of machines of the Fourdrinier type, and the facilities for removal and replacement of the making wires of such machines. By-the several features of the invention, a substantially new type of Fourdrinier machine is provided, the objectives of which are to obtain higher speeds of operation in the making of various grades of paper than would ordinarily be obtainable in making like grades on a Fourdrinier machine of conventional character, to give superior paper formation at such higher speeds, to make the wet paper sheet with both sides alike or much more nearly alike than when made by conventional practice, to provide facilities for changing the wire much more conveniently and far more quickly than heretofore, and which machine, by virtue of its simplification and relatively small size, will give a large saving in floor space, savings in cost of wires and in losses incident to wire replacement, savings in pulp, savings in original investment, upkeep and operation.

The invention will be described with reference to an illustrative process and machine and certain contemplated modified practices and machines shown in the accompanying drawings:

In said drawings:

Fig. 1 is a side elevation of a machine of one practicable construction embodying and adapted for practicing the invention.

Fig. 2 is a section of the vat and suction breast roll.

Fig. 2a is a detail view showing a cross-section of a portion of a vat side wall and improved deckle means.

Fig. 2b is a detail view of Fig. 2, showing a modification.

Fig. 31s a view half in front elevation and half in section of the suction breast roll and its supports; this view being shortened by omitting most of the intermediate portion of said breast roll and bringing its end portions close together.

Fig. 4 is -a sectional view representing a modification.

Fig. 5 is a sectional view representing another modification.

Fig. 6 is a cross-sectional view of the machine in condition for wire replacement, and of means associated therewith for wire replacement.

hoFig. '7 is a sectional view of an inverted suction Fig. 8 is a side elevation of a frame used for wire replacement, with an indication in dotted lines of the machine in condition for wire re- 5 placement.

' Referring first to the illustrative machine shown in Figs. 1 to 3, it will be observed that this machine has a short making wire I which passes around a breast roll 2 and a suction couch roll 3; the upper run of the wire being supported by a few table rolls 4, a series of fiat suction boxes 5, a supporting roll 6 between the first and second .sets of flat suction boxes, and a guide roll I;

while the lower run of the wire is engaged by 15 guide rolls 8 and an adjustable stretch roll 9 by which the wire is maintained in proper tension, said stretch roll being'adjustable within the limits of its two extreme positions which are indicated in Fig. 1 by the dotted lines 9 and 9 1 At the outset it will be noticed that the breast roll 2 is much larger in proportion to the other machinery than the ordinary breast roll of a conventional Fourdrinier paper making machine. This large breast roll is of the suctiontype, providing a vacuum area on the upper half of its ascending side. The pulp solution from which the wet paper sheet is made is supplied to the wire on said vacuum area of the breast roll, which vacuum area is sealed by the solution and wet sheet which forms from the fibers contained in said solution. The suction breast roll is preferably of the type comprising a rotating cylindrical metal shell, closely perforated, and an internal stationary suction box cooperating with the in terior surface of the shell to enclose a space in commimication with suitable vacuum pumping apparatus, preferably a high power positive rotary vacuum pump (not shown). However the suction box equipment in this instance is of a type to divide the vacuum area of the breast roll longitudinally into zones, and to permit maintenance of difi'erent degrees of vacuum action on the different zones of said vacuum area. For this purpose, as shown in Fig. 2, the suction box i0 is longitudinally divided internally, by partitions ll, into a series of separate suction compartments, in this instance four compartments l2, l3, l4, IS, the length of which corresponds to the width of the paper sheet to be made. These sep- 50 arate compartments communicate with the vacuum pumping apparatus through separate passages controlled by separate valves presently to be referred to. By adjustment of said valves the vacuum or suction in the several compartments of 65 and rest on standardsul'l rising from fixed base members or supports ll. The supporting stand- I1 and their base members it are shown as pipe sections of large dimension. In the operation of removing and replacing the making wire I, as hereinafter referred to, it is necessary to remove the supporting standards l! or supports i8. Hence, to permit quick removal of said standards I! or supports II, the suction box extensions may be detachably secured to said standards by swing bolts or the like, while said standards may be similarly detachably secured to the base members or supports II which are detachably bolted to the floor.

As shown in Fig. 3, the suction roll shell is equipped with annular heads rigidly secured to the ends of the shell. Mounted on the suction box extensions within said heads are annular supports or rings 2i. The heads 20 are rotatably mounted or journalled on said rings 2i through suitable interposed antifriction bearings 22. These bearings may be of any suitable roller type, each bearing comprising rings having confronting grooves or raceways and a series of bearing rollers arranged between said rings. Attached to the heads 2. are annular cover plates 23 by which the bearings are concealed and housed.

To facilitate erection and also allow axial motion of the suction breast roll if desired, the supporting rings 2i are mounted on the suction box extensions through roller supports. As shown in Figs. 2 and 3:the said supporting rings 2| are constructed at opposite sides with bearing members 24 arranged horizontally and parallel with the axis of the suction roll. These bearing members bear on rollers 25 which bear on tracks or supports 26 carried by the suction box extensions, the axis of said rollers 25 being at right angles to the axis of the suction roll. By this construction the two supporting rings 2| together with the suction roll journalled thereon can move axially as a unit. The rollers 25 and parts 24 and 26 are shown arranged in recessed portions of the supporting rings 2|. By confining said rollers 25 between the vertical surfaces 21 and opposite flat surfaces of the suction box extensions, and by forming said rollers with beveled peripheries engaging correspondingly shaped grooves in the bearing members 24 and tracks 26, the supporting rings 2i are held firmly against movement other than axial. By forming the suction box extensions with flanges 20 and 29 (Fig. 2), the end openings in the suction roll are substantially closed. The purpose of providing for axial motion of the suction roll is to permit application of a device for moving the roll to and fro axially for shaking the wire i in case a wire shake should be desired. However in the practice of the method provided by the present invention, as hereinafter more fully set forth, the use of a wire shake will ordinarily not be necessary. Aside from the matter of a shake, the construction described, having the roll-supporting rings 2| mounted on the roller bearings on tracks carried by the suction box extensions, facilitates erection.

As before stated, the suction box compartments i 2, I3, I, i 5 communicate with the vacuum pumping apparatus through separate passages controlled by separate valves. These valve controlled passages may be in one or both of the suction box extensions and supporting standards therefor, it being contemplated that in narrow machines it will sufllce to exhaust the suction box compartments through one set of outlet openings at one end oi the box, while in wide machines it may be desirable to exhaust through two sets of outlet openings at both ends of the box. In the illustrative machine the exhaust is through the suction box extension and support therefor shown in Fig. l and at the right-hand end of Fig. 3. Said suction box extension is a hollow body internally partitioned by intersecting webs, one of which is indicated by dotted lines at 30 in Fig. l and the other of which is similarly indicated at 3i in Fig.

3. By means of said internal webs, the said suction box extension is divided into four passages which lead respectively from the four suction box compartments, the two passages below the web ll being respectively in communication with the suction box compartments l2 and I6, and the other two passages being respectively in communication with the suction box compartments i3 and H. The four passages Just referred to communicate respectively with four compartments in the supporting standard on pipe section I! which is internally partitioned by the webs 32 and 33 shown in dotted lines in Fig. l and by another unseen web similar to and intersecting the web 32. The said four compartments in the supporting standard ll communicate through openings controlled by valves 34 with a chamber which communicates through pipe 35 with the vacuum pumping apparatus. The valves 34 are operated by screw rods having handwheels 38. The two valves shown in Fig. 1 control the passages leading from the suction box compartments i3 and H. The valves whichcontrol the passages leading from the suction box compartments i2 and I5 are behind those shown in Fig. l, as will be apparent from Fig. 3. It will be understood that in case it is desired to exhaust the suction box compartments through both ends, the passages and valves herein described as contained in the suction box extension and support shown at the right-hand side of the machine in Figs. 1 and 3 are to be duplicated in the suction box extension and support at the opposite side, and that said support at said opposite side may be connected through a pipe 31 with either an independent vacuum pumping apparatus or with the same vacuum pumping apparatus as that which connects with the suction box through the pipe 35.

The foregoing describes one practicable type of suction breast roll and equipment therefor whereby to provide an extended vacuum area to which the pulp solution is supplied, said area being divided longitudinally into zones subject to suecessively increasing degrees of vacuum action in the direction of travel of the wire, the lowest vacuum action being on the lowest zone and the next higher zone having a higher vacuum action and so on. The present invention includes the specific novel features of construction embodied in this suction breast roll and associated equipment, but in broader aspects the invention is not limited to any specific construction of breast roll other than one which will function to maintain a vacuum area with successively different degrees of vacuum on successively higher zones of said area. v

The pulp solution for paper sheet formation, i. e. water containing properly prepared and finely divided pulp fibres in suspension, is supplied to the wire on the vacuum area of the breast roll, under conditions to maintain a body of-said solution of desired'height bearing on a segment of said area, the solution being supplied at a constant rate and, under proper operating conditions, being utilized as fast as it is supplied. As

shown in Fig. 2 the solution is supplied from a head vat 38 to which the solution fiows from pipe 39. The solution flows from the head vat through the lower vat chute 40 to the breast roll, said chute being constructed to provide adjacent to the breast roll a suitable supplemental vat or solution holder 4! which cooperates with the breast roll to hold the body of the pulp solution which bears on the vacuum area. Said'solution holder 4i includes the extended side boards or vat side walls 42 having arcuate bottoms of curvature corresponding to and closely adjacent but not in contact with the cylindrical sheet forming surface which is provided by the wire on the breast roll. It will be understood that the body of pulp solution bearing on the breast roll is confined laterally by said side boards 42 or by said side boards and appropriate deckle means.

An improved deckle means is included in the illustrative construction. One of the two side boards 42 is shown in cross section in Fig. 2a. In this figure the inside surface of the side board is designated by the numeral 43. The side board has an-arcuate recess of oblong cross section containing an inflated rubber tube 44 formed with a rib 45 which projects through a slot in the side board to the inside lower corner thereof. The rubber tube 44, which may be similar to the inner tube of an automobile tire, is provided with a projecting tube 46 having a non-return check valve, whereby air can be pumped into the tube 44 for inflating it. The tube 44 is inflated to the degree necessary to force the edge of the rib 45 against the wire, thereby providing excellent deckling means. The side board is constructed with a lower separate section 41 to permit assembly of the parts. It will be understood that both side boards are of similar construction with respect to the deckling means, and that the edges of the deckle ribs 45 bear on the wire in vertical planes substantially coincident with the end walls of the suction box compartments. The solution holder 4i may be constructed to permit lateral adjustment of the side boards 42, and the suction box compartments may be provided with adjustable end deckle heads, in order to permit manufacture of different widths of paper sheets. Such details are not illustrated, since laterally adjustable vat side boards and adjustable end deckle heads for suction boxes are well-known in the art.

In Fig. 2, the numeral 49 designates a rectifier consisting of a perforated plate in cylindrical form disposed in the vat chute transversely thereof. This rectifier, which may be a mutilated hollow cylinder having its cylindrical wall closely perforated, is mounted on the shaft 50 which is rapidly oscillated, preferably both rotatably and axially, by any suitable mechanism (not shown), thereby oscillating the rectifier so as to diffuse or agitate the pulp solution flowing therethrough and prevent or oppose the orientation of the pulp fibers in parallelism.

The pulp solution could be supplied to the wire in other ways than as indicated in Fig. 2. For ex ample, the solution could flow at a regular rate upward to the level desired to be maintained in any suitable vat cooperating with the breast roll to hold a body of solution bearing on a segment of its vacuum area. However the arrangement shown in Fig. 2 is desirable since, due to the hydraulic head behindthe flowing body of water supplied to the wire I, or in other words due to the higher level of the liquid in the head vat 38 than in the vat chute, the solution is supplied under a velocity head or with a momentum, which assists in the flow of the water from the/solution through the wire and web of stock depositing thereon.

Having thus far described the illustrative machine generally, and also particularly with reference to the specific construction of and various improved features embodied in the suction breast roll and suction equipment therefor and means for supplying the pulp solution to the wire, reference will now be made to the method of paper making practiced thereon.

The process of wet sheet formation which takes place on the suction breast roll is one in which the deposition and compacting of stock on every square inch or other unit area of the traveling wire is induced by vacuum action successively increasing as the web of deposited stock builds up, whereby to compensate for the progressive loss of gravity head and the increasing resistance to flow of water from the solution through the wire due to the increasing thickness of the web. In Fig. 2, the several strata of pulp solutionwhich bear on the successive zones of the vacuum area of the breast roll are indicated by horizontal dash and dotted-lines dividing said strata. The said strata are designated by the numerals 5|, 52, 53, 54. The top level of the liquid in the solution holder 4| is designated by the numeral 55. It will be apparent that the gravity head is greatest on the lowest stratum, which sustains the weight of the liquid above it, so that, if there were no vacuum action to be considered, the liquid pressure would be greatest on the lowest zone of the vacuum area. On the other hand this zone is subjected to the least degree of vacuum. Every succeeding zone of the vacuum area is under a less gravity head and greater degree of vacuum action than the preceding zone. The uppermost zone is under the least gravity head (which reduces to zero at the liquid level) and the greatest vacuum action. This tends to equalize the flow of water from the supplied solution through the wire throughout the whole area on which the body of solution bears, and hence through every unit area of the wire from the time of deposition of the first fibers until the completion of the web of deposited stock on such unit area. Consequently it tends to equalize the velocity with merits and so that the total discharge just takes care of the total stock supplied or removes all water from the solution supplied to the breast roll (excepting that percentage of water which is tenaciously held in the deposited stock itself). This causes the wet sheet to build up substantially uniformly and promotes perfect formation at high speeds. The increase of vacuum action on each succeeding zone of the vacuum area makes up for the loss of head on that zone and also for the resistance to flow due to the increasing thickness of the web. The fiow being approximately equalized throughout the whole area of the forming surface on which the body of pulp solution bears, the fibers deposit on the wire at substantially the same rate and equal velocities as the wire passes through the successive zones of the vacuum area, while the deposited stock is held to the wire with increasing intensity as the building up of the sheet proceeds. Thus nearly ideally uniform conditions exist during the whole process. As all deposited stock is tightly held to and moves with the wire at the same velocity as the wire, there is substantially no opportunity for fibers to roll or form lumps, and as the force inducing the flow and deposition of fibers increases on the successive zones there is practically no opportunity for the dragging of deposited stock from the sheet as it passes through successive strata of the solution.

As the uppermost zone of the vacuum area, being the zone of highest vacuum, extends beyond the level of the body of pulp solution bearing on the breast roll, the advantageous effects mentioned are continued until the wet sheet has passed entirely from and free of the solution. By the action of the highest vacuum on the sheet after it emerges from the body of solution, an advantageous compacting and moisture reducing action is also obtained. By maintaining the level of the solution which bears on the breast roll approximately at or nearly as high as the uppermost part of the roll, and by forming the suction compartment 15 so that the last zone of the vacuum area extends beyond the point where the wire runs straight, i. e. beyond the vertical center line of the roll as seen in Fig. 2, the web or sheet of wet stock on the wire is held tightly thereto and is traveling at the same velocity as the wire as it goes off horizontally at full speed. Moreover the wet sheet by the time it leaves the influence of the suction should be as intact and of as low a moisture content as the sheet made on a conventional type of Fourdrinier machine when it reaches the first of the flat suction boxes. Hence there is no need of a long series of table rolls and shake sections as found on the ordinary Fourdrinier. Though in some-cases a process in accordance with this invention may be employed for forming a sheet which when it leaves the vacuum area is still so wet as to render it advisable to employ a short forming table and short deckle straps on the wire, and a shake for the wire', yet ordinarily such expedients will be unnecessary. The illustrative machine has no shaking mechanism. It has a short series of table rolls 4, although even these may be more than necessary in many specific practices. It

has short deckles 48 which may be of the samemay be passed almost at once over the fiat suction boxes 5 and then passed over the suction couch roll 0 which performs the usual function of subjecting the traveling sheet to a constant high tension vacuum action sufiicient to expel a certain amount of the tenaciously held water in the sheet and thus reduce it to condition for handling through ordinary press equipment or for undergoing the ensuing operations required in paper manufacture.

For best results in paper formation, the stock used should be highly dilute; it being desirable that the pulp solution supplied to the wire should contain only about or even less than per cent of properly prepared and finely divided pulp flbers in suspension,i. e. about or less than one part by weight of fibers to about 400 parts of water. In high speed paper making on conventional Fourdrinier machines it has not always been possible to use as highly dilute stock as desired, owing to the difliculties of removing the water therefrom through the wire, which difficulties have led to the use in modern high speed Fourdriniers of longer forming tables and 'wires, more table rolls and more extensive suction box equipment. Moreover in high speed paper making on conventional Fourdriniers there is a tendency for the stock settling on the wire to lag behind the wire. The stock even if supplied to the wire from high speed slice nozzles tends to lag behind the wire as it progresses, causing or allowing pulp fibers to roll or gather into lumps or conglomerations, and thus giving a spotty paper formation readily apparent when the finished paper sheet is held to the light. This difiiculty with the conventional Fourdrinier has been somewhat reduced by the employment of wire shakes or devices for jogging the forming table. However with the method herein described it is possible, using stock of even mixture and extremely high dilution, to obtain at high speeds an almost perfectly formed sheet, on a short wire, without any shake.

It will be apparent that the method of wet sheet formation herein described is superior to that which takes place on the type of machine in which the wet sheet forms over the vacuum area of -a suction roll on a wire passing around said roll, but in which the whole vacuum area or part thereof on which the body of solution bears is under the same degree of vacuum; for in such prior type of machine, due to the variation in the gravity head from the bottom to the top of such area, and also the progressive resistance to flow through the wire resulting from the increasing thickness of the web of fibers building up on the wire, the water does not flow through the wire substantially uniformly throughout said area, and not all water is drawn from the solution that ought to be, some of it remaining in the vat; moreover in said prior type of machine the fibers are deposited on the wire at different velocities and are held with progressively diminishing force as the formation progresses, so that the movement of substantially all deposited stock at precisely the same speed as the wire is not insured and there is opportunity, due to the constant churningof the body of solution by the rotating cylinder, for the washing or tearing of loosely felted fibers from the layer of deposited stock and for the rolling of loosely felted fibers on the surface of the stock layer, with consequent imperfactions in formation. On the other hand, by the method of the present invention, the water can be drawn from the solution through the wire approximately uniformly throughout the segment of the vacuum area on which the body of pulp solution bears, and as every unit area of the wire traverses the successive zones of said segment the fibers are deposited thereon at approximately the same rate and velocity, and the fibers are held to the wire and web of stock building up thereon with increasing force on the successive zones, giving substantially uniform conditions throughout the process and insuring the retention of substantially all the deposited stock, the movement of all deposited stock at the same high speed as the wire, and avoiding or minimizing opportunity for the dragging ofi oi fibers or the rolling of fibers into lumps or conglomerations.

Another advantageof this method is that it permits reduction in the work of filtering white water. Ordinarily all white water recovered from a paper machine is filtered for recovery of the short fibers that pass through the wire. In the process provided by the present invention, the various discharges of white water from the suction breast roll can be segregated. The water received in the suction box compartment i2 will have a relatively large amount of short fiber, which should be recovered by complete filtering in the usual way. But as the wire passes across the lowermost stratum of solution, it is accumulating a part of its paper web, which is a most excellent filtering medium so that the water received in the next suction box 13 should contain much less flber. Due to the increased thickness of the filtering medium on the wire as it traverses the upper strata of the solution, the water received in the suction box compartments i4 and I5 should be as clear as white water that has ordinarily been filtered by passing through the commonly used save-all filters, and hence the water discharged from the suction box compartments i4 and I5 will not require filtering but can be immediately reused as filtered white water. Thus the filtering work required for recovery of short fiberin the water drawn through the making wire may be considerably reduced. It is apparent that instead of conducting the entire discharge from the suction box through the pipe to a single vacuum pumping apparatus, the discharge from the suction box compartments l4 and i5 could be segregated from the discharge from the other compartments and conducted to a separate vacuum pumping apparatus. It is also apparent that in the illustrated machine, assuming the suction box extension and support therefor at the left-hand side of the machine to be equipped with passages and valves duplicating those previously described with reference to the right-hand side of the machine, and assuming said left-hand support to be connected by a pipe 31 with a separate vacuum pumping apparatus, that the valves at the right-hand side of the machine controlling passages in communication with the suction box compartments l3 and I4 could be closed, while the valves at the left-hand side of the machine controlling passages communicating with the suction box compartments i2 and I3 could be closed, and thus the suction box compartments l2 and I3 would be exhausted by one vacuum pumping apparatus through one side of outlets at one end of the box and the suction box compartments l4 and I5 would be exhausted by another vacuum pumping apparatus through the other set of outlets at the opposite end of the box.

Reference will now be made to certain modified or elaborated methods of wet sheet making, involving the process of formation hereinbefore described, and to certain apparatus for carrying out such modified methods, each or which apparatus.

may be considered as embodied, for example, in a machine of the general type disclosed in Fig. 1.

In Fig. 4 the making wire 51 passes around a suction breast roll 59 of the same general character and mode of operation as that shown in Fig. 1 but having in this instance a plurality of suction boxes 59, 69, 6|, each internally partitioned or divided longitudinally into a series of separate suction compartments which are exhausted through vacuum pumping apparatus connected with the respective compartments through separate passages controlled by separate valves. Pulp solution is supplied to the wire on the several vacuum areas provided by the several suction boxes, the solution being supplied from head vats through the

chutes

62, 93, 64 which are formed to cooperate with the breast roll to hold the solution thereagainst. These chutes may be equipped with rectiflers 85 similar to the one shown in Fig.2. The pressure of the solution on the vacuum area provided by each vacuum box increases on the successive zones or such area in the direction of rotation of the breast roll, while the successively higher degrees of vacuum are maintained on the said zones as before. As the wire travels with the breast roll across the first suction box 59 a layer of stock is deposited on the wire by the forming method already described; and as the wire travels with the breast roll across the second suction box 69 a second layer is deposited on the first by the same forming process; and as the wire travels with the breast roll across the third suction box 6| 9. third layer of stock formed in like manner is deposited on the second. In this method the paper sheet can be formed in layers either of the same or different stocks. However the paper sheet formed by such method is substantially different from an ordinary sheet of paper board or other plural ply paper in that it more closely resembles a homogeneous sheet, the layers being tightly interlocked and not readily separable. It is apparent that with this method the sheet can be made with a surface layer or layers of finer stock than the intermediate layer. The suction boxes 59, 60 and iii are formed and arranged so that the high vacuum zone of the vacuum area provided by one box is immediately adjacent to the first or low vacuum zone of the vacuum area provided by the next box. Thus the paper sheet is substantially always under suction from the time of the depositing of the first fibers to the time the sheet passe from the influence of the last suction box. This insures the retention of all deposited stock at allstages of the operation and prevents the centrifugal force of the water contained in the stock from pulling stock from the wire with resultant imperfections in formation. Opposite the suction boxes 59, 6|], 6| is a suction box 66 exhausted by suitable pumping apparatus and the vacuum area provided by which is sealed by an endless apron of rubberor impervious felt or the like running about suitable rolls 91. The purpose of the suction box 66 is to oppose the pull on the shell by the group of suction boxes 59, 69, 6|. It is contemplated that the suction breast roll 58 will be of still greater diameter than the suction breast roll shown in Fig. 1.

In Fig. 5 the making wire 68 passes around a suction breast roll 69 having a suction box Ill. The suction box I0 and its connections and vacuum pumping apparatus are substantially similar to those described with reference to the machine of Fig. 1, except that the suction box 19 is in this instance divided into a greater number of compartments, each connected with the vacuum pumping apparatus through a separate valve controlled passage. The pulp solution is supplied to the wire on the vacuum area provided by the suction box, the solution being supplied from a head vat through the chute H formed with the solution holding portion 12 and having a rectifier 13. An ordinary head vat 14 is mounted above the solution holders 12 and arranged to deposit stock upon the web of fibers formed on the wire as it travels the arc of contact with the body of solution contained in the solution holder 12, the outlet from the head box 14 being arranged to supply pulp solution over the high vacuum zone of the vacuum area of the breast roll. With this arrangement the paper sheet formed by the method of formation previously described can be surfaced with a layer of fine stock. A longitudinal partition I5 is shown arranged in the vat chute so as to separate the zone of liquid which bears on the first zone of the vacuum area from the superposed body of liquid. The space between the bottom of the vat chute and the partition 15 may be supplied with pulp solution from "the pipe 16. With this arrangement it is possible to form the sheet with a bottom layer of one kind of stock, an intermediate layer of another stock, and a top layer of another or superior stock deposited by the flow of solution from the ordinary head box H. The hydraulic head on the lower stratum of liquid below the partition 15 should balance the head above said partition so i as to prevent any tendency to leak around said partition or to bulge it, The partition I5 is slotted at 11 to accommodate the oscillatory rectifier. with this arrangement, as also with that of Fig. 4, the separate controllable outlets from the various suction box compartments permit separate handling of two or three types of white water.

One of the hardest things to accomplish on an ordinary Fourdrinier is to produce a paper sheet of substantially the same appearance on both sides. The diiference in appearance between the opposite sides of the paper sheet, as ordinarily made on a conventional Fourdrinier machine, is due in part to the im rint of the wire on one side of the sheet and in part to the fact that the application of suction to the wet paper sheet is always on the wire side. The illustrated machine of Fig. 1 embodies a means tending to overcome this difliculty and'by the use of which paper can be made with its opposite sides of approximately the same appearance. For this purpose a shorttop wire or endless apron I9 of wire cloth is arranged above the making wire. This top wire travels around guide rolls 88 mounted on axles 8|. The lower run of the top wire engages the top surface of the paper sheet and travels therewith, the top wir'e being driven by the paper sheet in the same manner that a dandy roll is driven. If desired the top wire can be positively driven in synchronism with the machine to run at the same speed as the lower wire. The paper sheet is drawn against the top wire by the action of inverted fiat suction boxes 82. These suction boxes 82 are mounted in a frame 83 which may rest on the main frame of the machine, said frame also carrying theaxles of the guide rolls 80. As showri the rollers are positioned so that the suction boxes 82 are arranged between the two sets of ordinary flat suction boxes 5. Thus the paper sheet is carried between two wires, namely between the making wire I and the short top wire 19, and the suction is applied alternately to the bottom and top sides of the paper sheet, drawing the sheet alternately against the bottom wire and top wire, the final suction box, namely the last box of the series 5, being at the underside of the paper sheet so that the sheet will leave on the bottom wire and go to the couch roll 3 in the ordinary manner. This method, in addition to giving approximate similarity of appearance to opposite sides of the paper sheet, will also increase the strength of the paper due to the fibrillae of the fibers being turned in both directions, up and down, and so interlocking better.

The use of inverted suction boxes to draw the paper sheet against the top wire requires a special suction box construction to insure the discharge of water extracted from the paper sheet by the upper flat suction boxes. An example of such a construction is shown in Fig. 7. In this figure, the suction box comprises an inverted box having a bottom filler member 84 and a bottom plate 85 attached thereto. Vertical holes 88 of small diameter are drilled through the bottom plate and filler member. The upper portions of these small holes or passages 86 are of slightly larger diameter than the lower portions, and receive small tubes 81, the interior diameters of the small brass tubes being equal to the inside diameters of the lower parts of the passages 86, so that small diameter smooth bored holes or passages are provided from the bottom surface of the perforated bottom plate to the upper ends of the said tubes. The tubes project up into the suction box, which is exhausted through the opening 88 and suction pipe 89 connected with any suitable suction pump. The purpose of this construction, involving a multiplicity of small bored tubes or passages for application of suction to the bottom side of the suction box, is to insure the discharge of moisture. If moisture is sucked with air through a vertical glass tube, the moisture will start up the tube in slugs which, if the tube is fair sized, will break and run down the side of the tube to the next slug and so on until it runs out at the bottom. But with the use of tubes of very small diameter, say from to inside diameter, the tendency of the moisture to separate and fall back down the tubes will be largely overcome, or in other words the suction will draw up the moisture slugs quickly through the small tubes. As the moisture is drawn by the suction action up through the small vertical tubes it may tend to fall back into the tubes, and to prevent this a series of small curved baffles 90 are provided, to insure the discharge of the moisture laterally of the tubes. For this carrying oil? .of the moisture to the exhaust passage, the upper surface of the tiller member 84 is declined or slopes toward the exhaust pipe as shown.

The making wire of a Fourdrinier is ordinarily driven by the suction couch roll. On account of the drag on the wire imposed by the fiat suction boxes there is liability of slippage with resultant undue wear on the wire and irregular or injurious effects on the wet paper sheet being made. With the large suction breast roll employed in the illustrated machine the load on the making wire will be still heavier. It is intended therefore to drive the wire coniointly by the suction breast roll and the suction couch roll, these two rolls being driven in synchronism at the same surface speeds. As shown in Fig. 3, the suction breast roll is equipped at its left-hand end with a sprocket wheel 83 or driving member attached to the roll member or its cover plate by bolts as shown. This sprocket wheel is driven by a suitable sprocket chain or other drive 94 from the drive shaft of the suction couch roll, the drive being such as to give precisely the same surface speed to the breast roll as to the suction couch roll.

The suction couch roll 3 may be of any known and approved type of construction adapted for subjecting the wet paper sheet on the making wire to the action of a high vacuum. In" Fig. 1 the suction couch roll journal 95 is shown mounted in the bearing member 96 which is mounted on a pedestal 91. In the operation of removing the wire presently to be referred to, the pedestal 91 is removed. The bearing member 96 is therefore detachably secured to the pedestal by swing bolts or the like, and the pedestal is similarly detachably secured to its base 98, the latter being permanently attached to the floor.

Reference will now be made to certain features of construction in the illustrative machine, whereby to make adjustments necessary for the change of the making wire, and to an improved method and means for changing the wire. For convenience, the side of the machine shown in Fig. 1 will be referred to as its front side. The driving sprocket from the suction couch roll shaft to the sprocket wheel of the suction breast roll is at the back side of the machine. The supports for the suction breast roll and for the suction couch roll have already been described. These supports are independent of the rest of the machine framing, or in other words the suction breast roll and suction couch roll are each independently supported. The other parts of the machine are supported by a machine frame comprising a pair of large side frame members I00, hereinafter referred to as the side frames.

Said side frames I00 are carried by a pair of large levers I M fulcrumed on supports mounted behind or beyond the back side of the machine as shown in Fig. 6. Said levers have tail extensions I03 which bear on removable plates I04 resting on supports I05. Pivoted to said supports are swing members I08 carrying large jack screw I01 which bear on the ends of the lever erg: sions I03 and hold them down against the removable plates I04. The levers are thereby rigidly held in the normal position shown in Figs. 1 and 6.

It will be seen that the entire portion of the machine between the suction breast roll and suction couch roll is carried on the two large levers IOI, being thus supported from means arranged at the back side of the machine. However the machine is constructed so that the machine as a whole, including the suction breast roll and suction couch roll, can be supported by said levers and contracted in length, permitting removal of the supports for the suction breast roll and front support 91 for the suction couch roll. The machine being thus contracted as a whole and all parts including the suction breast roll and suction couch roll being supported from the back side, the making wire can be easily slipped off from the front side of the machine and a new making wire can be slipped over it from said front side by the convenient method and means hereinafter described.

As shown in Figs. 1 and 6, the levers IOI carry a pair of longitudinal tracks or rails I08, the upper surfaces of which are in the same horizontal plane when the levers are in normal position.

The machine side frames I00 are supported each by two sets of bearing rollers I09 which bear on said tracks. Associated with each set of rollers is a cage IIO which may be attached to the machine side frame and the cross rods of which space the rollers. Secured on a cross shaft III are pinions II2 meshing with horizontal racks H3 and'lll, the upper racks H3 being on the machine side frames and the lower racks Ill being on the tracks I08. The ends of the cross shaft III are squared for application of cranks by which to operate said shaft. The purpose of the rack and pinion connection between the tracks and the machine side frames is to permit adjusting the machine frame relative to the levers for contracting the length of the machine as a whole. The machine frame is partially supported by a pair of jacks II 5, one under each side frame near the suction breast roll. These jacks II5 sustain a sufficient proportion of the load to hold the machine frame steady and to prevent vibration; These jacks are of a type to permit quick adjustment so that they can be quickly withdrawn and quickly replaced. Thus in the normal position of the levers I 0| the entire weight of the machine, or of that portion of the machine which is carried by the side frames I00, is not sustained by said levers, since a substantial proportion of the weight is sustained by the jacks. The machine frame also has additional support at its end adjacent the suction couch roll by means of horizontal bars II6 which are rigid with the side frames and project therefrom and enter horizontal guideways I H in the suction couch roll bearing blocks 96, in which guideways the side bars IIB are slidably fitted for the purpose of permitting the machine frame to be moved toward the suction couch roll. As shown in Fig. 1, the bearing block 96 has an adjusting screw II8 which is normally tightened against the bar IIB so as to make a rigid connection between the machine frame and the support for the suction couch roll. An additional adjusting screw H9 is provided to be tightened against the bar when the machine frame is moved close to the suction couch roll.

As before stated the machine as a whole, including the suction breast roll and suction couch roll, can be supported by the levers IOI. As shown the supporting rings 2| on which the suction breast roll is journalled are connected with the machine frame by bars I20. It will be understood that there is one of such bars at each side of the machine, each of said bars I connecting one of the side frames I00 with one of the' roll supporting rings 2 I. The said bars I20 are shown connected to the parts I00 and 2I respectively by pivot joints I2I of the vertical pivot-type, so as to permit axial motion of the breast roll in case a wire shake should be applied.

The mach ne side frames I00 are also equipped with large rigid members I22. one at each side of the machine, which are adapted to be rigidly fastened by bolting to the heads of the suction breast roll, whereby, in conjunction with the bars I20, the suction breast roll can be connected with the machine side frames so rigidly as to permit the said roll to be supported by said side frames. The side frames can also support the suction couch roll through the projecting bars H0.

In preparing the machine for changing the wire, it is necessary to elevate the top wire 19 and inverted suction boxes 82 sufficiently to enable the making wire to be withdrawn and the new making wire to be inserted between the ordinary suction boxes 5 and the top wire I3. For this purpose the frame 83 which carries the suction boxes 82 and the axles for the guide rolls 80 is made separable by the bolted joints indicated at I23, permitting detachment of the portion of the frame above the making wire. The whole structure above the making wire may be removed, but in the illustrated machine means are provided whereby it can be elevated sufllciently to raise the lower run of the top wire I9 clear of the making wire. As shown, the guide roll axles 3| are carried by levers I23 fulcrumed on standards I25 which may be conveniently mounted on the levers IN. The rear ends of the levers I24 are connected to the tail extensions I03 of the levers I M by adjustable tie rods I26 equipped with turn buckles I 21, by adjustment of which turn buckles the tie rods can be shortened, thereby canting the levers I23 and lifting the equipment which is above the making wire to a position such that it entirely clears the wire.

The changes necessary to be made in the machine in preparation for the changing of the making wire will now be described, it being understood that these operations need not be made in the precise order herein stated. The following order is suggested.

First, remove the deckles 48. Unloosen the joints I23 of the frame supporting the equipment above the making wire, and adiustably operate the turn buckles I21 until the said equipment is elevated to a position sufliciently clear of the making wire. Knock out the plates I04 from under the tail extensions I03 oi the levers IOI, and tighten the screws I01 until the said levers IOI just take the weight of the machine. Remove the supporting jacks II! from under the machine side frames. Attach the members I22 to the heads of the suction breast roll, so that the suction breast roll is adapted to be supported by the machine frame. Remove the suction breast roll supports II or I3. Before removing the suction breast roll supports, the jack screws I01 can be adjusted to raise the machine frame slightly, so as to take the weight entirely from said supports and enable them to be easily removed. The machine is now ready to be contracted. To permit its contraction loosen the set screws H8 in the suction couch roll bearing blocks. By applying cranks to the ends of the cross shaft III, said shaft can be operated to shift the machine frame toward the couch roll, carrying with it the suction breast roll supported thereby, and thus contracting the length of the machine as a whole while also providing a suflicient space between the suction breast roll and the vat I to permit the removal and replacement of the making wire without interference by the vat structure. The machine having been thus contracted, the set screw H3 is tightened to connect the suction couch roll bearing members rigidly with the machine frame. The suction couch roll support 91 at the front side of the machine is then removed. The whole machine in contracted condition is now supported by the levers IOI, providing a cantilever support from the rear side of the machine, so that the slack making wire can be readily slipped off from the front side of the machine, and a new making wire can be substituted by passing it over the machine from the front side.

While the machine is being made ready for changing the wire, which may be done by part of the machine crew, another part of the crew may be making ready for applying the new making wire by the method and means now to be described.

In Figs. 6 and 8, the new making wire to be applied is designated by the numeral I28. This wire is strung around a series of poles I23 held between a pair of frames I30 and I3I, said frames being of such size and shape as to permit passing said frames or at least the frame I30 sidewise over the machine from the front side thereof, and the said poles being positioned in said frames so that the wire strung around the poles has such a contour that it can enclose the space which it is to occupy on the contracted machine. The two frames, which may be suspended from a crane, are connected by a top cross beam I32 having an eye I 33 for attachment of the hook of the cable by which the frames are suspended. The two frames are further connected by cross braces I34. The two frames are preferably alike, although it is only necessary that the frame I30 should be passed over the machine. The frames may be of the construction shown in Fig. 8. Said figure shows the frame I3I. As shown in said figure, the upper and lower parts of' said frame are connected by vertical members I35 and I36 which are intended to be removed when the frames are in use. The said frames or at least the frame I30 are constructed with removable lower sections 431, I38, m)

In preparing for application of the new wire, the said frames I30 and HI suspended by a crane are brought to any convenient position opposite or near the front side of the machine, with the frame I30 nearest the said front side. The new wire I28 having been placed between the two frames, the poles I23 are then mounted in the frames by passing-said poles through holes in the frame I3I and into holes in the frame I30. By operation of the crane, the frames carrying poles and wire mounted on the poles are moved sideways over the machine from the front side thereof, so that the frame I30 is passed over the machine to a position beyond the backside thereof as shown in Fig. 6, while the wire I23 is brought to a position surrounding the position which it will occupy onthe contracted machine. In Fig. 8, the outline of the machine in its contracted state is indicated by dotted lines, being surrounded by the wire I23. The frames having been brought to the position represented in Figs. 6 and 8, the poles I23 are withdrawn lengthwise through the frame "I, and the wire then drops to its position on the contracted machine. The frames are then removed. They can be removed by lifting them vertically, the lower sections of the frame I30 being first removed in order to allow said frame to clear-the levers IOI and other parts at the backside of the machine.

The whole operation for changing the wire, including the preparation of the machine for the change and the mounting of the new wire in the frames and carrying it into position and dropping it into place on the contracted machine as above described, is more convenient and far quicker than the operations for wire changing which have been employed in prior practice even with the most improved facilities known prior to the present invention.

In Fig. 1, oppositely inclined boards I40 are shown arranged to catch any water or moisture that may drip from the paper sheet and conduct such moisture into the save-all box III.

It will be understood that the illustrated machine may be variously changed in details of construction and arrangement to suit various conditions and requirements, and that it is not indispensable that all features of the invention be used conjointly since the same may be variously used in various different combinations and subcombinations.

If desired the solution holder ll may be provided with a removable top closure as shown at I42 in Fig. 2b. The depth of the solution bearing on the breast roll may be diminished by laying on the bottom of the solution holder a so-called depth deckle, consisting of a block or plate of desired thickness having a concave edge adjacent to the breast roll. By use of a number of depth deckles of different thickness, the depth 01' the solution may be controlled as desired. In Fig. 2b two depth deckles, one laid upon the other, are indicated at I43.

What I claim as my invention secure by Letters Patent is:

1. In a paper making machine, the combination with a making wire on which the wet sheet is formed, a top wire running in contact with the opposite side of the sheet from that in contact with said making wire, and a series of suction boxes arranged for drawing the sheet alternately against the two wires.

2. In a machine of the character set forth in claim 1 having an inverted fiat suction box across the bottom of which the top wire runs, the improved construction for said inverted suction box characterized by a bottom plate closely perforated with small holes and a multiplicity of small bore tubes rising from said holes within the suction-box, for the purpose described.

3. A paper making method characterized by continuously forming the wet sheet on a traveling porous medium and alternately drawing the sheet by suction against said medium and an and desire to opposing similar medium before the transfer of said sheet from the medium on which it is formed.

4. In a paper making machine, a suction breast roll, a traveling making wire passing around said roll, said roll comprising a rotating cylindrical perforated shell and a stationary suction box therein, said suction box having extensions proiecting through the ends of the roll, supports for said end extensions, rollers carried by said end extensions, said rollers having parallel axes at right angles to the axis of the shell, annular supports mounted on said rollers, and annular shell heads journalled on said supports, the said rollers permitting axial motion of the breast roll whereby a wire shake can be applied. v

- 5. In a paper making machine, a suction breast roll, a traveling making wire passing around said breast roll, said breast roll having suction equipment providing a vacuum area on a portion thereof covered by said wire, means for supplying pulp solution to the wire on said vacuum area, said means including a solution holder cooperating with the roll to hold a body of said solution bearing on a segment thereof, said holder having side walls with curved under-edges adjacent to the cylindrical surface which is provided by the wire on said roll, said side walls having curved recesses and slots extending from said recesses to the inner lower corners of said walls, and inflatable tubes in said recesses, said tubes having ribs extending through said slots and bearing against said surface to provide deckling means.

6. In a paper making machine, the combination with a traveling porous medium on which