US1867931A - Paper manufacture - Google Patents

Description

' My 39 1932. J. TRAQUMR ET AL, 1,867,931

PAPER MANUFACTURE Filed Sept. 2. 1950 l 2 Sheets-Sheet l July 19, 1932 J. TRAQUAIR ET Al. 1,867,931

PAPER MANUFACTURE Filed Sept. 2. 1930 2 Sheets-Sheel 2 kof vao

Patented July 19, 1932 UNITED STATES PATENTy OFFICE JOHN' TRAQUAIR AN D HERBERT A. XIDD, OF CHIILICOTHE, OHIO, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE MEAD CORPORATION, OF DAYTON, OHIO, A CORPORATION OF OHIO PAPER MNUFACTUBE Application filed September 2, 1930., Serial No. 479,189.

This invention relates to the manufacture aper.

ne of the principal objects of the invention is to provide a paper making apparatus which is simple and economical in construction, requires v'but a relatively small amount of space for its installation, is highly eficient and effective in operation, and is capable of producing a high grade paper or board of uniform characteristics.

Another obj ect of the invention' is the provision of such a paper making apparatus which is adapted to form a paper or board web of uniform characteristics within a forming zone of limited extent. A further object of the invention is the provision Aof paper making apparatus in which a uniform degree of suction is maintained adjacent the forming zone to produce a formed web of substantially constant thickness.

Other objects and advantages of the invention will be apparent from the following description, the accdmpanying drawings and the appended claims.

In the drawings, in which like characters of reference designate like parts throughout the several views thereof- Fig. l is a diagrammatic elevational view of a paper forming machineconstructed in accordance with this invention; some of the parts being broken away for clearness of illustration;

Fig. 2 is an enlarged vertical sectional de tail of Fig. l; Y

Fig. 3 is a fragmentary vertical sectional view similar to Fig. 2 of a modified form of paper forming machine;

Fig. 4 is a fragmentary sectional view similar to Fig. 2 illustrating a further modication of paper forming machine;

Fig. 5 is an enlarged detail of a portion of Fig.` 4; and

Fig. 6 is a fragmentary horizontal sectional view taken on the plane of the line 6-6 of Fig. 4.

Referrin to the drawings, which disclose a preerred embodiment of the invention, the numeral 10 in Figs. 1 and 2 designates a rotatable paper forming roll of a paper making machine. B way of example, a rotary forming roll of t e type shown in the .co-pending application of John Traquair, Serial No. 402,340 filed October 25, 1929, is disclosed. -A stock inlet 11 of'suitable type is provided having means for flowing a stream of stock onto the peripheral surace of the paper forming roll to form a paper web thereon; the stock flow being preferably in a direction approximately tangential to the surface o the roll. The paper forming roll has a foraminous cylindrical surface to which suction is applied on the under side in order to quickly withdraw the water which is flowed onto the roll'surface with the paper forming stock so that the paper web will be formed within a relatively short angular movement of the roll.,` A device, generally designated 14, is provided for removing the formed paper -web from the roll. Suitable means are provided on the exterior of the oraminous cylindrical surface to permit the suction to be electively created within the roll prior to the position'of stock iow and to permit a relatively high degree of suction to be maintained upon the form-A ing surface as it enters the forming zone.

As shown, the roll is provided with a central hub 15. The hub extends outwardly beyond the ends of the roll to form journals which are mounted in suitable supporting bearings which permit the roll to rotate. The roll is driven as by means 'of a gear fixed to an extended end of the hub 15 and which has meshing with it a suitable driving gear connected to a source of power.

A cylindrical member such as a wood deck 23 is concentrically positioned with respect to the hub 15 and is supported therefrom by hollow members or manifold connections 24 which are attached at their outer ends to the wood deck 23 and at their inner ends to the. hub l5. A plurality of spacing blocks 25-are secured to the outer surface of the wood deck 23 and are provided with curved outer surfaces which form a cylindrical support for the forming surface supporting means such as a wire wrapping 26. The wire wrapping 26 binds the whole in assembled relationship. Adjacent turns of the' wire are spaced apart sufficiently to provide ample openings for the passage of air and water therebetween while providing a good support for the outer foraminous wire or felt forming surface 27. The spacing blocks are formed as segments whose outer surterial.

faces are curved and are grooved, as shown at 28, in the direction of the longitudinal axis of the roll to provide a plurality of ribs 29 to support the encircling Wire 26. Suitable longitudinal grooves 30 are provided on the under side of the blocks 25 and are of such depth that suliicient wood is left between the grooves 30. and 28 to support the wire. A plurality of transverse or peripl.- eral grooves 31 are also formed in the spacing blocks 25, and provide communication between grooves 28 and 30, while at the same' time leaving suflicient support for the wire. .For this purpose the transverse grooves 31 are preferably arranged in staggered relationship in the dierent spacing blocks 25. Division strips 32 extend completely across the roll parallel with the longitudinal axis and are uniformly spaced around the periphery of the wood deck v23 to divide the area between the deck 23 and the wire 26 into a'series of compartments 33. Each hollow tube 24 communicates with a passage 34 in the deck 23 to thereby provide communication between lthe space within the tube 24 and its respective compartment 33. During the cycle of operation of the roll the compartments 33 are subjected to changes. in pressure communicated through the tubular members 24, and such changes. in pressure are thus operative upon the paper forming surface 27'. rll`his forming surface may be made of conventional paper making wire or fabric such as filter cloth or other suitable ma- 'lihe ends of the compartments 33 are closed by suitable members positioned adjacent the parallel ends of the roll so that the perimeter of the roll thus comprises a series of closed compartments covered by a foraminous paper forming surface.

The supporting members 24 are of considerable area in cross section to provide unrestricted communication with the interior of Ythe dempartments 33.. The inner ends of the supporting members 24 connect with passages 36 extending longitudinally through the hub 15 of the roll. A separate passage 36 is provided for each compartment 33 and there are preferably a'plurality of members 24 extending between each passage 36 and its respective compartment 33 so that the condition of suction or pressure existing in any compartment will be equalized throughout the axial length 5@ of the compartment. The passages 36' termi- (fili nate in openings 37 provided in the face of ,la valve plate 38 which is attached to the end of the hub 15 and is adapted to rotate with.

the hub. Preferably the passages 36 extend throughout the axial length of the hub and are provided with a `valve plate 38 at each of the valve plate 38, is positioned to contact flush with thedisc like surface of the valve plate 38 and is providedV with manifold openings 40, 41 and 42 which are adapted to register with the openings 37 in the valve plate upon rotation of the roll and valve plate. The openings 40, 41 and 42 extend through the deck 39 and are closed on the outer side of the deck by manifold covers 43, 44 and 45 respectively; the manifold covers being attached to the deck 39 as by means of bolts 46.

As shown, part of the valve deck has been broken entirely away, another part is shown in section, while the balance is illustrated inelevation. The manifold 43 for the opening 40 is connected by a pipe 47 to some suitable means. such as a pump, for creating suction in that portion of the roll having openings 36 `which lie within the extent of the manifold ',face before it again enters the suction zone.

.The various compartments 33 and the roll forming surface are thus subjected during predetermined periods in the cycle of rotation of the roll to suction, air pressure, and washing water.

lln the operation 'of the machine, stock is dowed from the inlet 11 onto the porous surface of the rotating roll. The inlet 11 as diagrammatically shown comprises a flow box 53 with which is connected a pipe 54 for the supply of paper forming stock; suitable staggered bames 56being provided in the usual manner. A suitable apron 57, made of flexible material such as rubber, is provided for the discharge of paper forming' stock onto the roll. As shown, the apron 57 is attached to the bottom member 58 of the inlet and curves upwardly adjacent the forming surface so as to direct the flowing stream of stock onto the surface of the rotating roll in a direction substantially tangential to the roll surface. As the stock is flowed onto the forming surface of the roll, water is rapidly withdrawn from the stock as the roll rotates due to the suction which is placed on the roll surface by means of the suction manifold 43 connected through the openings 37 to the hollow tubes 24 and thence to the compartments 33. y

lin order that the web may be quickly formed within a limited angular travel of the roll the compartments 33 are placed under suction prior to their entrance within the forming zone. It has been found that in machines of this character Where the web is formed rapidly under the influence of suction, and particularly on board webs of substantial thickness, a web having transverse areas of varying thicknessis apt to be pro-` duced if a uniformly high degree of suction is not present inthe forming compartments throughout the forming zone. Suitable means are provided to maintain suction within the compartments so that when the compartments enter the forming zone they will be under a uniform and relatively high de-A gree of suction and a web of uniform characteristics and substantially constant thickness will be formed thereon. For this pur' pose, the suction manifold 43 is so positioned relative to the stock inlet that suction vbecomes effective within the compartments 33 when they reach an angular position in ad- Vance of the stock inlet, such as the angular position represented by the radial line 60 in Fig. l. The amount of angular advance of the suction zone will vary with the speed of rotation of the formingroll, the degree of suction employed, the size of the forming roll and of the suction compartments as well as the capacity of the suction pump and'size of the connections, the character of the forming surface, and other factors, but this can be' readily determined in each instance by ex the roll rotates the compartments 33 succes-A .sively move toward the transferpoint and in passing beyond the range of the suction manifold 43 they move within the range of the manifold 44 which, as mentioned, is adapted to supply pressure to the compartments 33. The pressure exerted on the porous roll surface tends to disengage the formed paper web from the roll surface and transfer it to the traveling member which is suitablv guided for contact with the formed web.

The transfer of the web may be aided by the application of suction to a compartment 67 positioned in contact with the carrier 65 on the side opposite to that in contact with the paper web. To prevent excessive frictional drag and resulting wear on the carrier 65 when passing through the area covered by the suction compartment 67- an intermediate member may be provided such as an endless foraminous web or felt 68 suitably supported on guide rolls 69 and positioned between th carrier and the suction compartment. Further rotation of the forming roll carries the compartments 33 out of registration with the pressure manifold 44 and into a zone wherein washing Water is supplied from the manifold 45 for thoroughly cleansing the forming surface ofy the roll prior to the reentry of that surface into the suction forming zone.

taining suction in the compartments upon entering the suction zone and prior to the By provision of suitable means for main of a web of uniform thickness. As shown, an

impervious web or blanket 70 comprising a rubber sheet or other suitable flexible material is positioned over the forming surface of the roll adjacent to and ahead of the stock inlet. The blanket 7 O is suitably supported as by means of a bar 71 carried by a portion y of the stationary framework of the machine and extending transversely of the forming surface. The member 70 is adapted to be secured to the bar 71 in a manner to permit the blanket 70 to lie in contact with the face of the roll. As shown, the blanket 70 extends from the position of stock flowin a direction opposite to the travel of the forming surface an amount in excess of the peripheral width of a' compartment 33, preferably at least one and one-half times the peripheral width of a compartment 33. This is coordinated with the angular advance of the suction zone so that a compartment 33 is preferably entirely covered by the blanket 70 prior to the forward edgefof the compartment reaching the angular posit-ion represented by the line 60 where the suction becomes effective. The

provision of the blanket 70 permits a coml partment 33 to be exhausted to a high degree lof suction upon entering the suction zone so that" upon entering the forming zone the paper web will be formed thereon quickly and without any tendency for the stock to -flow about over the forming surface, as

would occur if but a low or irregular degree of suction were present.

Suitable means are provided to reduce the frictional drag of the blanket 7 0 on the forming surface' 27 incidental to the creation of suction within the compartments 33. As shown, this is accomplished by creating suction on the exposed face of the blanketto substantially balance the suction active on the interior face of the blanket. For this purpose, a suction box 7 3 is provided adjacent the stock'inlet 11 and is preferably formed integrally therewith; the bottom wall 58 of the stock inlet providing the top wall for the suction box 73. The suction box 7 3 comprises an open sided structure positioned with the open side adjacent the blanket 70 and isprovided nwith a suction pipe 74 connecting l to a suitable source of suction for exhausting the interior of the suction box. The box 73 extends along the periphery of the roll a distance substantially equal to the length of the blanket and suitable means are provided for sealing the interior of the box from atmospheric pressure. As shown, the bottom face 75 of the box extends inwardly toward the forming surface and is provided adjacent the innemend with a flexible lip 76 of rubber or other suitable material which is attached to the member 75 as by means of a nailing strip 77. The lip 76 is adapted to contact with the exposed face of the blanket 70 and to provide an effective seal between the blanket and the suction boxl along the face 75 of the box. rlhe lip 57 of the stock inlet provides a suitable sealing means at the top face 58 of the box and, as shown, contacts with the upper edge of the blanket. Suitable side deckles 80, one of which is shown, are attached to the side walls of the box 7 3 and provide an e'ective seal between the side walls of the suction box and the forming surface. These deckles may be positioned so as to bear at their lower ends upon the rubber blanket and at their upper ends, beyond the extent of the rubber blanket, may be spaced slightly from the forming surface an amount suflicient to provide a suitable seal to prevent any lateral flow of the stock prior to a degree of drying l ofthe paper web that will enable it to be maintained on the forming surface. Upon creating suction within the box 73 an outward pull is produced on the exposed face of the member 7 0 which tends to oset the suction pull from the compartments 33 to thereby reduce the frictional drag and consequent wear upon the blanket and the forming surface of the roll. The degree of suction within the box 73 may be maintainedsubstantially equal to that within the compartments 33 or it may vary somewhat either above or below that of the compartments without appreciably aecting the operation' of the device.

'lllhe relatively high degree of suction produced in the compartment 33 before entering the forming zone permits a substantially uniform degree of suction .to be maintained over the entire roll surface within the suction forming zone. rllhis uniform degree of suc` tion is also maintained over the forming surface by having no abrupt dividing walls between adjacent compartments. rllhe dividing walls as described. comprise upstanding members 32 which have a narrow contact with the inner surface of the wire wrapping 26 so that there is substantially no portion of the forming surface which is not subjected to suction. Any variation in surface suction which might occur adjacent the points of contact of the members 32 is eliminated by separating the roll forming surface from the ends of the members 32 by the'layer of wire wrapping 26 and the thickness of the forming surface 27. Suction from the compartments on either side of the dividing walls is suicient to creep around the edges of the members 32 and thus provide a uniform degree of suction over the roll surface.

In Fig. 3 a portion of a paper making machine is shown comprising a roll l0 having in contact with it a blanket 85 which is adapted to aid in maintaining suction within the compartments 33 prior to their entrance within the forming zone. As shown, the blanket 85 is supported by means of a bar 87 suitably supported from and 'extending transversely of the machine, and positioned below a suction box 73. The suction box is positioned adjacent the exposed face of the blanket 85 and is adapted, by connection at 74 to a suitable source of suction, to create a Vsuctional pull on the exposed face of the blanket. rlhe upper wall 58 of the suction box serves also as the bottom wall for a stock inlet 11 and is provided adjacent the surface of the roll-l0 with a dexible lip 88 which not only serves to direct the stock flow onto the wire in a direction approximately tangential to the roll surface but serves also to provide a sealing means for the suction box. S'uitable deckles 80 are positioned to seal the side walls of the suction box adjacent the forming surface and a liquid seal is provided for the bottom wall of the suction box. As shown, a rotatable sealing roll 90 is positioned to bear against the forming surface and is adapted to be rotated at substantially the peripheral speed of the forming surface either by frictional contact therewith or by positive drive means. 'llhe roll 90 dips within liquid such as water carried within a trough 91 positioned below the roll 90. A second roll 93 similar in general characteristics to the roll 90 is positioned to contact with the exterior surface of the bottom wall 75 of the suction box and dips within liquid contained in a trough 94 positioned therebeneath. A third roll 96 is adapted to contact with the rolls 90 and 93 and, with the latter mentioned rolls, provides a liquid seal between the face 75 of the suction box and the forming surface of the roll. Upon rotation, liquid is carried on the surface of the roll 90 from the trough 91 to seal the line of contact between the roll 90 and the forming surface of the roll l0. rllhe liquid is carried to the surface contact between the rolls 90 and 96 i 101. Two of the guide rolls are positioned` vious blanket 100 supported on guide rolls frictionally driven by contact therewith at substantially the peripheral speed of the forming surface. With this construction, differences in pressure on the inside and outside of the forming surface are immaterial and servein fact to hold the rubber blanket in vsealing engagement `with the forming surface and to secure a better driving contact. rIhe upper guide roll 101 is positioned somewhat below the bottom wall 58 of the flow l box, and a space is thus formed just beneath the suction forming zone which the blanket does not overlie. In order to seal this space. a exible strip 103 is attached at spaced oints by nailing blocks 104 to the lower surace ofthe bottom 58 of the flow box. The

ble strip 103 bears against a second loop 108 positionedibeneath the lfirst loop and fastened in position by nailing blocks 109 and 110 carried by a trough member 111. The ends of the exible strips 103 and 108 extend across to' the `side wall 106 and are turned in and fastened to the side wall as indicated at `112.- The`trough member 111 extends between the oppositeside walls 106, and at its forward portionv carries a third exible strip 114 maintained in loop form by the nailing strips 115 and 116. The loop of strip 114 is .in vsealing engagement with the surface ofthetraveling blanket `100 across the width thereof, and extends beyondand is turned in and fastened to the side walls. Any other suitable means may be used to provid@ satisfactor sealing at this area. The compartments 33 fmayl thus be effectively evacuated before `entering the formingzone,

and air leakage into the evacuated compartments satisfactorily prevented by the overlying traveling blanketor. sealing member,

without the production of objectionable frictional drag upon the forming surface.

The terms paper and paper web are herein employed as meaninga brous web generally and include high grade papers as well as thicker papers, cardboard, building board and the/like.v The provision of means for @i creating suction on the compartments of a forming surface prior to entrance within the forming zone is applicable to the formation of a thick board, such as building board, which isordinarily formed at slow speed. In the manufacture of such board where the forming surface moves at a relatively slow speed, the pool of stock introduced onto the forming surface is given an opportunity to flow somewhat, if a relatively high degree of suction is not present in the compartments. By providing a uniformly high degree of suction this flow action of the stock is minimized and, being effective upon the vstock as soon as itis introduced onto the forming surface, rapid formation of the thick board web results and a board of uniform characteristics and substantially constant thickness is provided. This type of machine permits the formation of building board of substantial thiclmess at higher speeds than have heretofore been generally used. For example, this machine may be satisfactorily used to form a board web suitable for building or insulating board at a speed of about feet per minute or higher. The present invention provides a forming machine of this character which effectively overcomes any tendency toward uneven web formation and is capable of forming a web of uniform thickness at high rates of speed. The present invention is also applicable to a high speed paper machine where the forming surface of the machine may travel at a speed of 500 feet per minute or more. In this case the thin paper web forms readily by rapid extraction of the water due to the uniformly high degree of suction on the forming surface and a paper of high quality and uniform thickness results.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms o f apparatus, and that changes may be made therein Without departing from the scope of the invention which is defined in the appended claims. What is claimed is:

- `1. Apparatus of the character described for making a sheet of paper comprising a movable foraminous member providing a forming surface, a suction compartment positioned beneath said movable member and stream of fibrous stock onto the forming surface of the movable member to form a web thereon, the suction being effective-on said compartment prior to the position ofstock supply, and means to maintain the suction in said compartment prior to the position of stock supply, said means comprising an impervious blanket positioned to contact with the forming surface side of said movable member.

2. Apparatus of the character described for making a sheet of paper Comprising a foraminous member providing a movable forming surface, a plurality of suction compartments positioned adjacent one another beneath said movable member and opening to atmosphere through said member, means for producing suction within said compartments, means for supplying fibrous stock to the forming surface of said movable member including an inlet adapted to flow a stream of fibrous stock onto the formingl surface of the movable member to form a web thereon, the suction being effective on said compartments prior to the position of stock supply, and means to maintain the suction in said compartments prior to the position of stock supply, said means comprising an impervious f blanket positioned to contact with the forming surface side of said movable member and extending in the direction `of travel'of the movable member over an area greater in length than the extent of a suction compartment.

3. -Apparatus of the character described comprising a movable foraminous member providingv a forming surface, a suction compartment positioned beneath said movable member and opening to atmosphere through said member, means for producing suction within said compartment, means for supplying iibrous stock to the forming surface of said movable member to form a web thereon, the suction being effective on said compartment prior to the position of stock supply, means to maintain the suction in said compartment prior to the position of stock supply, said means comprising an impervious blanket positioned to contact with the forming surface side of said movable member, and means for applying suction* to the exposed side of the impervious blanket.

4. Apparatus of the character described comprising a movable foraminous member providing a forming surface, a suction compartment positioned beneath said movable member and opening to atmosphere 'through said member, means for producing suction within said compartment, means for supplyl ing fibrous stock to the forming surface of said movable member to form a web thereon, means to maintain the suction in said compartment prior to the position of stock supply, said means comprising an impervious blanket positioned to contact with the forming surface side of said movable member, means for applying suction to the exposed side of the impervious blanket including an open sided suction box, means for sealing the open side of the suction box, and means for producing suction within said box. y

.5. Apparatus of the character described comprising a movable foraminous member providing a` forming surface, a suction compartment positioned beneath said movable member and opening to atmosphere through said member, means for producing suctionK within said compartment, means for supplying fibrous stock to the forming surface of said movable member to form a web thereon, means to maintain the suction in said compartment prior to the position kof stock supply, said means comprising an open sided suction box, means providing a seal between the open side of the box and the forming surface of the movable member, means for producing suction in-said box, and means comprising an impervious blanket adapted to contact with the forming surface side of the movable member'within the confines of the suction box to provide a seal between the interior of the suction box and the suction compartment.

6. Apparatus of the character described comprising a foraminous member providing a movable forming surface, a suction compartment positioned beneath said foraminous member and opening to atmosphere through said member, means for producing suction within said compartment, means for supply ing fibrous stock to the forming surface of said movable member to form a web thereon,

means to maintain the suction in said compartment prior to the position of stock supply, said means comprising a suction box associated with the exterior of the forming surpositioned beneath said movable member and I opening to atmosphere through said member, means for producing suction within said compartment, means for supplying fibrous stock to the forming surface of said movable member including an inlet adapted to flow a stream of fibrous stock onto the forming surface of the movable member to form ra web thereon, means to maintain the suction in said compartment prior to the position of stock supply, said means comprising a movable endless impervious blanket adapted to contact and move with the ,forming surface side of the movable member.

8. Apparatus of the character described for making a sheet of paper comprising a movable foraminous member providing a forming surface, a suction compartment positioned beneath said movable membery and movable therewith, said suction compartment opening to atmosphere through said member, means for producing suction within said compartment, means for supplying fibrous stock to the forming surface of said movable member including an inlet adapted to iow a stream of fibrous stock onto the forming surface of the movable member to form a Web thereon, means to maintain the suction in said compartment' prior to the.

inous forming member providing a periph-` eral surface for said roll and suction pockets, means for supplying fibrous stock to said forming surface including an inlet adapted to How a stream of fibrous stock onto the forming surface of said rotatable forming roll to form a web thereon, and means to maintain suction in said pockets prior to the position of stock supply, said means comprising an impervious blanket positioned to contact with the exterior side of the foraininous forming member.

10. Apparatus of the character described comprising a rotatable forming roll, a forami-nous forming member providing a peripheral surface for said roll, compartments positioned within the forming roll and rotatable therewith, means for producing suction Within said compartments ata predetermined angular positioning of the compartments, means for supplying fibrous stock .to said forming surface to form a web thereon, said suction forming means being adapted to produce suction in said compartments in advance of the zone of stock supplys an impervious blanket. positioned to contact with the exterior side of the portion of the foraminous forming member under suction prior to the position of stock supply, and means for maintaining suction on the exposed face of the blanket.

11. A paper making machine of the character described, comprising a rotary forming roll having an outer forming surface, said roll having' aplurality of compartments formed therein and opening to atmosphere through said outer forming surface, said compartments being adapted to rotate with said roll, means for owinga stream of paper forming stock onto said outer forming surface of said roll to form a paper web thereon, means for producing suction Within said compartments Vat a. predetermined angular positioning of` said compartments, a suction box positioned to contact with the exterior surface of the portion of forming surface under suction prior to the position of stock supply, and means for maintaining suction within the suction box.

12. A. paper making machine of the character described comprising a rotary forming roll, a foraminous paper forming surface for said rollya suction compartment communicating with said forming surface, a stock inlet for flowing stock onto said forming surface to form a web thereon, means for connecting said compartment to a source of suction, said suction compartment being operative to place said forming surface under suction in adlrance of the area where the stock flows onto the forming surface, and means for maintaining suction in the compartment prior to entrance in'tdthe forming zone, said means comprising a member adapted to contact with the exposed forming surface throughout the extent of the suction area in advance of the forming zone, and means for producing suction on'the exposed face of said contacting member.

13. A paper making machine of the character described comprising a rotary forming roll having an outer forming surface, a plurality of compartments formed Within said roll and opening to atmosphere through said outer forming surface, said compartments being adapted to rotate with said roll, means for flowing a stream of paper forming stock onto said outer forming surface of said roll to form a paper web thereon, means for connecting said compartments to suction prior to the entrance of the compartments into the paper forming zone, means for maintaining suction in said compartments until they enter the forming zone, said means comprising a flexible blanket positioned in contact with the forming surface adjacent the beginning of the forming zone and extending opposite to the direction of travel of the forming surface an amount greater in extent than thelength of a suction compartment, a suction box positioned to contact with the exposed face of said blanket, and means to produce suction within said box.

14. 1n a paper making machine of the character described, having means for flowing a a stream of paper making stock onto a forming surface to form a web thereon; ay'traveling foraminous forming surface onto which the said stock is {iowed at the forming zone, means for supplying a .uniform relatively high degree of-suction to said forming surface adjacent and prior tovsaid forming zone to provide for the formation of a paper web of uniform thickness within a short travel of the forming surface, and means for maintaining suction prior to the entrance of the forming surface into the forming zone, said means. comprising an impervious blanket positioned in contact with said forming surface, and means tending to equalize the effective pressures on the exterior and interior surfaces of said blanket.

15. 1n a 'paper machine of the character rotary roll.

l producingsuction within said suction box, a

described, a rotary vacuum forming roll, a allel to and in contact with the other sealing stock inlet therefor comprising a flow box rolls.

having a lower wall and side walls open ad- In testimony whereof we hereto aiiix our jacent one endfor owing a stream of stock signatures. r

5 onto the forming surface of the vacuum roll, l JOHN TRAQUAIR. 3

a suction box mounted beneath the lower wall HERBERT A. KIDD.

- of the iow box, means for producing suction within said suction box, and sealing means positioned between the suction box and the 75 16. In a paper machine of the character described, a rotary vacuum forming roll, a stock inlet therefor comprising a iow box v having a lower wall and side walls open adja- 15 cent one end, a iexible lip fixed to the lower wall of the flow box to direct a iowing stream of stock onto the forming surface of the vacuum roll, a suction box mounted beneath the lower wall ofthe iow box, means for sealing blanket positionedin contact with the forming roll opposite the suction box and extending to approximately the position of the flexible lip, and sealing means positioned between the sealingvblanket and the suction box. 17. In a paper machine of the character described, a rotary vacuum forming roll, a stock inlet for iowing a stream of stock onto the forming roll, a suction box mounted below said inlet and having an open side defined by walls shaped to conform to the curvature of and closely approach the forming roll, a sealing blanket positioned in contact with said forming roll and extending from the exterior of the suction box to close the open side thereof, and sealing means effective between the exterior of the suction box and the blanket.

18. In a paper machine of the character described, a forming roll, a suction box positioned on the exterior of said roll and having an open side extending adjacent said roll, sealing means operative between a wall of said suction box and said forming roll, said sealing means comprising a rotatable sealing roll extending parallel to said forming roll and in contact therewith, and a fiexible lip positioned on said suction box and contacting with said rotatable sealing roll. f 115 V19. In a paper machine of the character v described, a forming roll, a suction box positioned on the exterior of said roll and having an open side extending adjacent said roll, sealing means operative between a wall of v 12o said suction box and said forming roll, said sealing means comprising a rotatable sealing roll extending parallel to and in contact with said forming roll, a secondrotatable sealing roll positioned parallel to said first mentioned 125 sealing roll and adapted to' contact with a wall of said suction box, troughs positioned below said sealing rolls and adapted to supply a liquid coating to the surfaces of said 66 rolls, and a third sealing roll positioned par- CERTIFICATE OF CORRECTION.

Patent No. 1,867,931. July 19, 1932.

JOHN 'TRAQUAIR ET AL.

It is hereby certified that error appears in the printed specification of the Page 6, line 100, claim above numbered patent requiring correction as follows: 6, for the-word "and" read of said; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of October, A. D. 1932,

M. J. Moore,

Acting Commissioner of Patents.

(Seal)

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