US2535732A

US2535732A - Sealed wet end for paper machines

Info

Publication number: US2535732A
Application number: US647367A
Authority: US
Inventors: John E Goodwillie
Original assignee: Beloit Iron Works Inc
Current assignee: Beloit Iron Works Inc
Priority date: 1946-02-13
Filing date: 1946-02-13
Publication date: 1950-12-26
Anticipated expiration: 1967-12-26

Description

1950 J. E. GOODWILLIE 2, 3 3

SEALED WET END FOR PAPER MACHINES Filed Feb. 13. 1946 3 Sheets-Sheet 1 F 2 q. 1. I

g 94 2 l Mai 92 90!. l; 9p 4 M 8/ 90b 74 't J 7 I I am Dec. 26, 1950 J. E. GOODWILLIE SEALED WET END FOR PAPER MACHINES 3 Sheets-Sheet 3 Filed Feb. 13. 1946 [27 '2 1*? far Java 5 @000 W. L m" Patented Dec. 26, 1950 SEALED WET END FOR PAPER MACHINES i John a. Goodwillie, neiomwa, assignor to Beloit Iron Works, Beloit, Wis a corporation of Wisconsin Application February 13, 1946, Serial No. 647,367

6 Claims.

This invention relates to a wet end for a paper making machine which effects pressure formation of paper stock into a paper web free from streaks, uneven weight distribution, and uneven fiber arrangements.

Specifically, the invention deals with a paper machine wet end which forces paper formation from a stock pool before the stock issues from under a slice and up to the point where the web is removed from its forming surface by subjecting the stock and web on the forming surface to materially higher absolute pressures than those existing under the forming surface.

In paper making machines equipped with conventional wet ends and head boxes, currents or swirls of paper stock are produced in the head boxes, and these currents have cross-flow velocity components which are effective to move part of the stock on the forming surface of the machine from its original position and pile it up in another position where the drainage of water through the forming surface sets the stock into streaked shetts. streaked sheet formation is more prevalent on conventional high-speed paper machines because, on such machines, the sheet must set quickly. and-the streaks are not evened out.

The present invention now provides a highspeed wet end for paper machines that eliminates streak formation by effecting the formation in a confined chamber in the presence of an excess of amount of stock and water. Any cross movement at a point where stock is forming on the wire does not. in the machines of this invention, result in the formation of streaks because the pool of stock and water continues to feed the 2 through the formation zone at any desired speed.

A suction couch roll cooperates with the forming forming area at all points. In the machines of i this invention the stock, while it is still in a fluid pond state, is caused to move with the forming surface in the same direction as the forming surface to eliminate disposition of fibers parallel with the direction of movement of the forming surface. Pressure formation occurs in advance of the slice and continues beyond the slice up to the point where the web is removed from the forming surface.

In the preferred embodiment of the invention, a foraminous cylinder, such as a cylinder mold, receives an endless forming wire therearound.

This forming wire is also trained around guide rolls spaced from the cylinder to direct the wire onto and off of a portion of the periphery of the cylinder. A stock chest, or feed box, is provided adjacent the ascending side of the cylinder and has a seal projecting therefrom into sealing relation with the forming wire on the cylinder, The stock chest carries a slice in spaced relation from the seal, and stock in the chest communicates directly with the forming wire along a formation zone between the seal and slice. The stock is maintained under pressure and may be circulated wire adjacent its point of removal from the cylinder. This point is preferably adjacent the descending side of the cylinder so that the stock on the wire will travel around the top portion of the cylinder between the slice and the couch roll. A sealing roll is provided in pressure nip engage;- ment with the couch roll and cooperates with end walls and seals to provide a sealed chamber above the cylinder beyond the slice. A felt guide roll is adjustably mounted in this chamber and receives a pick-up felt therearound to direct this felt through the nip between the couch roll and forming wire for picking up the newly-formed web from the forming wire. The sealed chamber is pressurized with compressed gas such as air to force drainage through the forming wire and cylinder. The drained white water in the cylinder can drop freely through the lower portion of the cylinder into a drainage sump which, if desired, can be evacuated.

The pressure formation occurring on both sides of the slice in the machine of this invention eliminates streaks or uneven fiber formation and, at the same time, makes possible extremely high speed paper formation.

It is, then, an object of this invention to provide a paper making machine with a pressurized wet end that eliminates uneven fiber formation and can be operated at very high speed.

A further object of this invention is, to provide a compact wet end for paper making machines that forces drainage of white water through a forming surface continuously from the time stock is initially deposited onto theforming' surface until the paper web is removed from the forming surface.

Another object of this invention is to provide a wet end for paper making machines wherein stock under any desired pressure flows at any desired speed against a moving forming surface, and is ejected under a slice directly into a pressurized chamber for forcing drainage of white water from the web being formed on the surface until the web is removed from the surface.

A still further object of this invention is to provide a sealed wet end for paper making machines having a pressurized formation chamber receiving the forming run of a forming wire therethrough together with a pick-up felt for removing the web from the forming wire before releasing pressure on the web.

A still further object of this invention is to provide a shiftable couch roll arrangement for a sealed paper machine wet end which accommodates movement of the couch roll without breakage of the suction connection.

A still further object of this invention is to accuse provide a suction roll assembly wherein drainage is effected through bellows type conduits that accommodate movement of the roll without breakage of drainage connections.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of a preferred example only, illustrate one embodiment of the invention.

On the drawings:

Figure l is a side elevational view of a sealed wet end for a paper making machine in accordance with this invention.

Figure 2 is a longitudinal cross-sectional view, with parts in elevation and with parts diagrammatically illustrated, of the wet end of Figure 1.

Figure 3 is a fragmentary transverse crosssectional view, with parts in elevation, taken along the line III-III of Figure 1.

Figure 4 is a fragmentary transverse crosssectional view, taken along the line IV-IV of Figure Figure is a fragmentary transverse cross-section'al view taken along the line V--V of Figure 1.

As shown on the drawings:

The sealed wet end ll] of this invention, as shown in Figure 1, includes transverse supporting beams ii and i2 carrying removable upright pedestals or columns i3 and I4 which columns, in turn, respectively support box frames l5 and i8. It should be understood, of course, that similar uprights or columns i3 and I4 are provided on the rear end of the machine for supporting the other end of the box beams i5 and i8. Brackets I! are provided on the beam 18 for supporting bearings l8 which rotatably carry a guide roll l9 between the columns i3.

Longitudinal beams 28 supported from the beams l8 and I6 carry bearings 2| for a foraminous cylinder 22. The cylinder 22 has axe 23 rotatably mounted in the bearings 2| A pan or tank 24 surrounds the lower portion of the cylinder 22 and is carried by the beams I8 and i8 as better shown in Figure 2. This tank provides a drainage vat for the cylinder as will be more fully hereinafter described, and has an outlet sump 24a in the bottom thereof for removal of white water.

The beam It carries brackets such as 28 which support bearings such as 28 for a guide roll 21. A cross shaft 28 is Journaled in the brackets 28 and has links 29 secured on the ends thereof. The lower ends of the links 28 are pivoted to the rear ends of brackets 38 which carry bearing supports 3i for another guide roll 32. Additional links 83 pivotally connect the forward ends of the brackets 30 with the forward ends of the brackets 28. A gear segment 34 is secured on the shaft 28 and meshes with a gear 38 on a shaft 38 carried by pedestals such as 31. Rotation of the shaft 88 will rotate the gear 38 to swing the gear segment 84 for rotat'ng the shaft 28 and thereby swinging the links 28 to shift the brackets 38 for swinging the guide roll 32 relative to the guide rolls I 9 and 21. A forming wire 38 is trained around all of the guide rolls, and also around the top portion of the cylinder mold 22 and the shiftable guide roll 32 maintains the forming wire 38 in a tightened condition. A cam 38 secured on the shaft 38 has a cable 48 trained therearound and secured thereon. Counterweights 4| are suspended on this cable for tending to rotate the shaft 88 in a clockwise direction thereby tending to drive the gear 88 for raising the gear segment 84 and lifting the links 28. Raising of the links 28 moves the bracket 88 and roll 82 in a direction to tension wire 88 and by properly proportioning cam 39 and counterweights II, the weight of the moving parts can be counterbalanced, regardless of their position. A second cam 42 is also secured on shaft 88 and receives a cable 43 therearound which is anchored thereto. Tension weights 44 are suspended on cable 42 and also tend to rock the shaft 88 in a clockwise direction to raise brackets 88. By properly proportioning cam 42 and tension weights 44 it is possible to apply a predetermined tension on the forming wire regardless of position of roll 32. The arrangement is such, therefore, that the roll 22 is shifted in response to changes in length of the forming wire 88 for maintaining a predetermined tension on this wire.

The above described structure is straddled by another frame construction comprising uprights 48 supporting longitudinal box beams 48 in spaced relation above the cylinder 22. A stock chest orfeed box 41 is mounted within the frame structure adjacent the cylinder 22. This stock chest 41 includes, as best shown in Figure 2, a vertical passageway P as wide as the forming wire 28 and receiving paper stock into its lower end from a stock feed pipe 48 fed from a centrifugal stock pump 48 and controlled by a valve in the pipe line 48.

The stock chest 41 has a forwardly projecting lip 41a carrying, at its forward end, a flexible apron seal 8| which rides on the forming wire 38 at a point just after the forming wire engages the ascending side of the cylinder 22. The cylinder 22 is driven in a clockwise direction by a driver connected to one of its axles 23.

The stock chest 41 also has a sloping slice wall portion 41b in spaced relation above the lip 41a thereof and slidably supporting a, slice bar 82 adapted to be raised and lowered by screw rods 82 having operating handles 83a. The slice bar 82 carries a tipped end member 84 which pro- .iects forwardly therefrom and is adapted to be raised and lowered on the slice bar 82 by rods such as 88 which are actuated by handles such as 88a. Clips such as 88 acted on by springs such as 81 hold the tip member 84 in sealed sliding relation on the slice bar 82. The slice member 84 is thus selectively adjustable along its length on the slice bar 82 and the slice bar 82 is adapted to be raised and lowered along the slice wall 41b. The slice member 84 is positioned adjacent the top of the cylinder mold 22 but still on the ascending side of the cylinder and is spaced from the seal 8| to define a formation zone Z on the forming wire and cylinder communicating freely with the interior of the stock chest along the entire width of the forming wire.

A baffle 88 is mounted in the stock chest 47 on a bracket 88 for swinging movement of its free forward end toward and away from the cylinder 22. A clamp 68 cooperates with the bracket 88 to hold the bathe in adjusted position. The clamp mechanism can, of course, be replaced with an operating rod mechanism accessible from outside of the stock chest. The forward free edge 88a of the bailie 88 lies behind the slice wall 41b in spaced relation therefrom so that the formation zone Z communicates between the front edge of the baflle and the slice with a stock surge chamber C in the stock chest above the amuse baiile 58. Stock from this surge chamber C can drain through a conduit 8| in the back wall of the stock chest immediately abovethe hinged end of the baffle 58. A pipe line 82 communicates with the drain conduit 8i and a pump 88 in the pipe line 82 can recirculate stock from the chamber C to the inlet pipe 84 for the centrifugal pump 48. A valve 85 controls now from the pump 83. I

The surge chamber C extends upwardly from the baflle 58 for a considerable distance so that. if desired. a high head of stock can be maintained. The top of the surge chamber C is closed by a door 88 so that the entire stock chest can be maintained under pressure. A shower pipe 81 is provided in the upper end of the surge chamber C to destroy foam on top of stock in the chamber and to keep the interior surfaces of the chamber clean. An air space is preferably maintained above the stock and the shower pipe 81 is mounted in this air space.

As best shown in Figure 2, a hollow box beam as is carried by the lohgitudinal top beams 45 and extends transversely therebetween. A top wall member 68 depends from the beam 88. A rear wall 18 depends from the rear of the top wall 88 and has a rearwardly extending portion 18a connected to the front wall of the stock chest 41. A front wall 1| depends from the front end of the top wall 88. Side walls 12 close the ends of the space embraced by the

walls

88, 18. and H to provide an enclosed space S above the cylinder mold.

Casings such as 13 (Figure 1) are built up on the side walls 12 immediately above the cylinder 22, and have removable end caps 14 secured to their lower ends and to the side walls. As shown in Figure 2, vertical tracks or ways 15 are provided in the casings 13 to slidably support carriages 18 carrying bearings 11 for a feltdirecting guide roll 18 which extends transversely across the space S above the cylinder 22. The caps 14 are removable to give access to the bearings 11. Vertical screw rods 18 project upwardly from the carriages 18 and are threaded through worm gears (not shown) in casings 88 mounted on the top beams 48. Worms (not shown) on a transverse shaft 8| mesh with the worm gears in the casings 88 to rotate the gears for raising and lowering the screw rods 18 to thereby adjustably position the felt-directing roll 18. A hand wheel 82 is provided for actuating the shaft 8 I.

As shown in Figure 1. brackets such as 88 depend from the top beams 48 and carry bearings 84 at their lower ends for rotatably supporting a sealing roll 85 forwardly of the roll 18 and above. the cylinder 22. Asshown in Figure 2, the front wall 11 carries a seal 88 engaging the periphery of the sealing roll 85. An air tube 81 backs up the seal 88 to urge it into sealing relation with the roll 85.

As best shown in Figures 1 and 3, levers 88 are pivoted to both side faces of both beams 48 to provide four depending couch roll-carrying supports. Each lever 88 has its free depending end pivoted to a link 88. Each pair of links 88, in turn, is pivotally supported from a double diaphragm unit 88 which is more fully described and illustrated in the copending application of Lloyd Hornbostel, Serial No. 687,728, filed July 30, 1945, entitled: Fluid Pressure Controlled Roll Assembly. These double-acting diaphragm units 88 have a central housing member 88a to which the links are pivoted, and diaphragms 88b overlie the top and bottom of the housing. Members 880 are clamped to the central portions of the diaphragm 88b. A rigid carriage :BI clamps these members to transmit forces applied to the carriage through the diaphragm to the housing 88a. Air or other gas is admitted under pressure to the diaphragm chambers in the housings 88a so that the diaphragm are gas-cushioned and will uniformly transmit forces applied to the carriage even when the housings become cocked relative to the carriage. These units 88, oi course, could be replaced with simple carriage constructions directly receiving the links 88.

The carriages 8| are siidable on ways provided by brackets 82 mounted on the top beams 48. The brackets 82 each carry a worm and gear casing 88 on the top thereof. A worm gear in each casing 88 receives, in threaded relation therethrough, a screw rod 84 secured to the carriage 8|. A cross shaft operated by a hand wheel 88 drives the worms (I shown) in the casings 88 to rotate the worm gears for raising and lowering the screw rods 84 and carriages ill. The levers 88 are thus swung about their pivots on the top beams 48.

Trunmons 81, at least one of which is hollow. are pivotally mounted between each pair of levers 88 on pivots 88. These trunnions 81 have arms 88 projectin forwardly therefrom and equipped with forked or yoked ends 88a. A single-acting diaphragm unit I88, more fully described and illustrated in the aforesaid Hornbostel application Serial No. 687.728, is pivotally mounted in the yoked end 88a of each arm 88. Each unit I88 includes a casing I88a providing a gas chamber and covered with a diaphragm I88b to the central portion of which is clamped a force-transmitting member I880. This member I88c is coupled through a coupling I8I with a screw rod I82 threaded through a coupling I83 that is pivoted to the ends of each pair of links 88. The screw rod I82 can be adjusted to swing the arms 88 relative to the links 88 and thereby move the trunnions 81 about their pivots 88.

The trunnions 81 carry elbow members I84 with at least one of the members being hollow and communicating with the hollow trunnion 81. These elbow members I84, in turn, support the suction box or gland I88 of a suction couch roll I88. The couch roll I88 includes a rubber-covered perforated cylinder I81 rotatable around the suction box I85 and this cylinder I81 is maintained in nip relation with the sealing roll 85 as best shown in Figure 2.

The hollow trunnion 81 is connected with a deformable bellows conduit I88 extending between the levers 88 to the passageway I88 provided in one of the box beams 48. The passageway I88 is evacuated by a suction pump (not shown) to evacuate the suction box I85 of the couch roll I88. The bellows conduit I88 will permit shifting of the couch roll without breakins the suction connection.

As best shown in Figures 1 and 2, the cross beam I8 supports a hollow box beam Il8 on the top thereof and a deformable bellows conduit III communicating with the interior of the beam H8 extends upwardly therefrom and is attached to a boss I841: on the hollow elbow member I84 for draining liquids from the .ln-.- terior of the suction box I85 so that these liquids need not be drawn upwardly through the pas-. sageway I88. The hollow box beam I I8 is evacuated by a suction pump (not shown) and white water is drained through the bellows conduit in into the passageway III. I

As shown in r-lgare 2, the suction box I05 carries seals Iooa acting on the cylinder ml to denne a suction area A on the lower portion of the cylinder. Another seal luoo is carried by the suction box I05 to act on the cylinder IuI au acent the mp between the rolls to and I06. This seal Iuoo prevents leakage through the perioratlons in the cylinder IIII irom the space a.

A compressor II2 diagrammatically shown as mounted on a beam on, supplies compressed air through a conduit I 13 to the interior or the transverse box beam 88. The compressed air from the box beam is supplied to the s ace a tnliJuin ports Ill in the beam 88 and H5 in the top wall 88.

As shown in Figure l, the side wall 12 for the space S has a seal plate H8 bolted thereon for carrying seals in sealing engagement with the ends of the cylinder 22, the suction couch red It, and the sealing roll 85. As shown in Figure 4, the side wall 12 has an outturried ledge 12:; with an upstanding flange 121) thereon to which the seal plate lie is bolted. The cylinder 22 extends into the pocket provided by the ledge 12a and this ledge carries a rubber sealing belt III having'a grooved face lying in close proximity to the apron cloth seal 5| which rests on the forming wire 38 on the cylinder mold 22. This apron cloth 5| as shown extends between the flange 12b and the seal piece II8 to be clamped therebetween. The seal belt II1 has grooves III! in the face thereof confronting the apron cloth 5| and water is supplied to the grooves through an inlet passage H8 for preventing lodgment of stock in close clearance spaces particularly in that section beyond the end of apron cloth 5| and where belt H1 is in close clearance relation with the forming wire 38 providing a water seal for the edges of the apron seal 5|.

The cylinder 22 has an end ring 22a carrying a smooth faced sealing plate I20 acted on by a sealing block I2I which is slidably carried in the seal casing IIB. A rubber tube I22 backs up the sealing block I2I and is inflated to urge the block into sealing engagement with the plate I20 for providing an efllcient seal which can be. lubricated with water from the grooves H8. The block I2I extends around the lower edge of the side wall 12 and, of course, the identical structure is duplicated at the other end of the mold.

As shown in Figure 5, the air cushioned block I2I extends around the rin 22a of the cylinder mold down to the front lower edge of the seal plate H8 at the point where the suction couch roll I00 is in nip pressure relation with the cylinder 22. The rubber cover I010 on the cylinder of the couch roll I08 terminates inwardly from the ends of the cylinder and the cylinder has a solid metal end portion I 01b which is spaced from the cylinder mold 22 and the space between this end portion and the cylinder mold is sealed. Grooves similar to those shown at H8 in the belt II1 can be provided to lubricate the contacting surfaces between block I2I and plate I20. A second arcuate block I23 is backed by another air tube I24 and urged against the edge of the cylinder I01 to seal the end of the suction couch roll. This block I28 extends up to the nip between the rolls I08 and 85 and a third block I25 then extends around the end of the roll 85 as shown in Figure 1.

Atube I28issecuredtobeam Illandeontaots the extended portion of the seal plate Ill in the space between the ends of roll I88 and cylinder mold 22 as shown in Fig. 1 to form a positioning support for the extended end of the seal plate H8. The tube'can be pivo on ears I21 on the seal plate. This tube can supplied with compressed air and communicates with the interiors of the air tubes I22 and I2 to inflate these tubes.

As shown in Figures 1 and 2, a pick-up felt I28 is trained around the suction couch roll I08 and around the felt directing roll 18. The pick-up felt enters the sealed space B through the nip between the sealing roll 85 and the couch roll I88 and then passes around the directing roll 18 to return over the top of the cylinder mold 22 through the nip between the mold and the couch roll I08. As indicated in dotted lines in Figure 2, the directing roll 18 can be raised and lowered so that the felt will have the desired lapping engagement with the web on top of the cylinder 22 and forming wire 38. When the roll 18 is raised to its dottedline position, the felt engages the web Just before it enters the nip between the cylinder and couch roll I08 but. when the roll is dropped to its solidline position, the felt will lap the web for a considerable distance in advance of the nip.

In operation of the wet end of this invention the cylinder 22 is driven to drive the forming wire 38 trained therearound. Stock is pumped through the passageway P of the stock chest 81 to supply stool; under pressure to the formation zone 21. The stock is circulated from the formation zone into the surge chamber C and recirculated from this surge chamber through the pipe line 82 back to the passageway P. The stock can be caused to move in the formation zone at the same speed as the forming wire 38 on which the stock is formed into a web, or at any desired speed relative to the forming wire. The stock is preferably maintained under superatmcspheric pressure so that formation in the zone Z will be speeded up. White water drains through the forming wire 38 and cylinder 22 into the interior of the cylinder and then drops through the bottom portion of the cylinder into the vat 24 from which it is removed through the sump 24a. Stock on the wire emerging from under the slice 54 enters the sealed chamber S which is maintained under superatmospheric pressure by air from the compressor H2. Further drainage of white water through the forming wire 88 and cylinder mold 22 thereupon takes place and the stock is immediately set into a web. The web is then covered by the pick-up felt and passes through the nip between the suction roll and cylinder mold while it is sandwiched between the forming wire and the felt. The suction area of the couch roll I08 transfers the web to the pick-up felt and of! of the forming wire. The forming wire emerging from the nip is separated from the web and the web travels on the underface of the pick-up felt to the press section and drier section (not shown) of the paper machine. A pan I25 mounted adjacent the couch roll I01 catches water ejected from the holes in the couch roll cylinder to prevent this water from dripping on the web-carrying pick-up felt I28. A seal I050 on the couch roll suction box I05 cooperates with the oiT-goinggseal I05a to define a sealed space B in the roll cylinder I01 which will hold water in the holes of the cylinder until these holes are above the bottom of the pan I25 whereupon they will discharge into the pan.

Formation of the web in the zone Z occurs in the presence of an excess supply of stock and water so that cross-current velocities do not cause streaks in the forming sheet. The pressure chamber immediately following the slice insures prompt setting of the stock into a web before any rearrangement of fibers can occur, so that the web will have a fiber structure consistent with the hodge-podge fiber arrangement in the stock pond.

The term pressurizing as used herein and in the claims is intended to mean any pressure loading or force.

From the above descriptions it will be understood that this invention provides a sealed pressurized wet end for paper machines wherein web formation both behind and in advance of the slice occurs under controlledpressure conditions which eliminate streaking and directional fiber formation. The machines can be operated at extremely high speeds, are quite compact, and free from heretofore-required shake equipment. Only relatively short forming wires need be used, thereby reducing the cost of wire maintenance.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A sealed wet end for paper making machines comprising a foraminous cylinder, a forming wire trained therearound, guide rolls for directing the forming wire around the upper portion of the cylinder only, a stock chest on one side of the cylinder communicating with th forming wire on the ascending side of the cylinder, a couch roll coaeting with the forming wire on the descending side of the cylinder, a sealing roll in nip engagement with the couch roll, wall means carrying seals enclosing a space above the cylinder, and means for introducing gas under pressure into said space for pressurizing said space.

2. In a paper making machine a frame, levers pivoted on said frame, means carried by said frame for swinging said levers, arms pivoted on said levers, means for shifting said arms relative to said levers, bearing brackets on said arms, a suction roll carried by said bearing brackets, a hollow trunnion carried by one of said bearing brackets, a suction box in said suction roll com- .municating with said hollow trunnion, and a flexible suction conduit for evacuating said trunion and suction box, said flexible conduit accommodating shifting of the 'suction roll by said levers and arms.

3. In a paper making machine a rotatable cylinder having a forming, surface thereon, structure cooperating with said cylinder defining a sealed space above said forming surface, means for pressurizing said sealed space, a couch roll cooperating with the forming surface for removing a web formed thereon, a guide roll in said sealed space, a felt trained around said guide roll, and means for moving said guide roll in said sealed space toward and away from said cylinder for lapping the felt around a predetermined amount of said forming surface in advance of the couch roll to travel with the forming surface through a nip between th forming surface and couch roll.

4. A sealed wet end for paper making machines comprising a cylinder, a forming wire trained around said cylinder, guide rolls spaced from said cylinder for directing the forming wire around the top portion of the cylinder, a couch roll cooperating with the forming wire on said cylinder, means for moving said couch roll circumferen tially of the cylinder to adjust the position of a nip between the couch roll and the cylinder, a sealing roll in pressure nip rotating engagement with the couch roll, seals coasting with the cylinder, the couch roll, and the sealing roll for defining a sealed space above the cylinder, a felt directing roll in said sealed space, and a pick-up felt trained around said felt directing roll having one run passing through the nip between the sealing roll and the couch roll and the other run passing through the nip between the cylinder and couch roll for lapping a web on the forming wire.

5. In a sealed wet end for paper making machines having structure defining a sealed pressurized space abov a forming zone on the forming surface of the machine, the improvements of a felt directing roll in said space, a pick-up felt trained around said roll, and means for shifting said roll relative to the forming surface of the machine to adjustably lap the pick-up felt for a predetermined distance on the forming surface.

6. A sealed wet end for paper making machines comprising a foraminous cylinder, a forming wire trained therearound, a stock chest extending along one side of said cylinder and communicating with the wire on said cylinder for depositing stock thereon. a couch roll coacting with said cylinder beyond said stock chest for removing a web from the wire, a felt-directing roll above the cylinder and between the couch roll and stock chest, a felt trained around said directing roll and through the nip between the couch roll and cylinder, means for ad ustably moving said feltdirecting roll to adjustably lap the felt on the forming wireon the cylinder, seals enactin with the couch roll and the stock chest to define a sealed space above the forming wire on the cylinder and around the felt-directing roll, and means for introducing gas under pressure into said space for pressurizing stock on the forming wire to force drainage therefrom through the wireand cylinder.

JOHN E. GOODWILLIE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date Re. 21,201 Qviller Sept. v5, 1939 1,798,821 Veyron Mar, 31, 1931 1,870,971 Sundstrom et al. Aug. :9, 1932 1,928,107 Lang Sent. 26, 1933 2,171,739 Berry Sept. .5, 1939 2,186,761 Malkin Jan. 9, 1940 2,345.64! Witham Apr. 4, 1944 2,396,694 Goodwillie et al. Mar. 19, 1946 FOREIGN PATENTS Number Country Date 528,352 Germany June 27, 1931 656,453 Germany Feb. 7, 1938