TITLE; A PRESS APPARATUS FOR A PAPERMAKING MACHINE

CROSS REFERENCE TO RELATED U.S. PATENT APPLICATION

The present application is a complete application of copending provisional application USSN 60/024,095 filed August 1 6, 1 996.

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a press apparatus for a papermaking machine.

More specifically the invention relates to a press apparatus which permits selective removal and installation of a felt, a bearing blanket, an extend nip module and a backing roll.

INFORMATION DISCLOSURE STATEMENT

Extended nip presses permit the removal of increased quantities of water from a formed web, thereby reducing the amount of thermal energy required in any subsequent web drying operation.

The present invention includes an inverted extended nip module which cooperates with a backing roll. The arrangement is such that a loaded press shoe slidably disposed within the module cooperates with the

backing roll for defining therebetween an elongate press nip for the passage therethrough of the web and felt.

The provision of the elongate press nip increases the residence time of the web within the press nip so that more water is removed from the web when compared with the more conventional roll couple type press.

In view of the massive proportions of the aforementioned module and backing roll, the removal and installation of such components and the removal and installation of a press felt and looped bearing blanket in the aforementioned configuration require the provision of very specialized equipment and techniques. Those skilled in the art are well aware that a press apparatus, according to the present invention, may typically be equivalent in size to a three-story residential dwelling.

The present invention provides a unique apparatus that facilitates selective removal and installation of the press felt, the bearing blanket, the extended nip module and the backing roll.

Therefore, it is the primary objective of the present invention to provide a press apparatus that facilitates selective removal of a press felt, a bearing blanket, an extended nip module, and/or a backing roll.

Other objects and advantages of the present invention will be readily apparent to those skilled in the art by consideration of the detailed description contained hereinafter, taken in conjunction with annexed drawings.

SUMMARY OF THE INVENTION

The present invention relates to a press apparatus for a papermaking machine for pressing a web.

The apparatus includes a frame and an extended nip module which is removably connected to the frame.

A backing roll is disposed beneath the module and is removably connected to the frame. The backing roll cooperates with the module for defining therebetween an elongate press nip for the passage therethrough of the web.

A felt extends through the press nip for receiving water removed from the web during passage of the web and felt therethrough.

A looped bearing blanket extends around the module, the arrangement being such that the blanket is disposed between the module and the felt during passage of the blanket through the press nip.

A positioning means is disposed above the module and is selectively connected to the module adjacent to a first location. The positioning means when connected to the module permits the movement of the module away from the backing roll.

Link means selectively extend between the frame and a second location adjacent to the module. The first and the second locations are spaced relative to each other. The arrangement is such that when the positioning means is connected to the module and in a first disposition thereof, and the link means extend between the frame and the second

location, the module is urged towards the backing roll for defining therebetween the press nip.

When the positioning means is in a second disposition thereof, and the link means extend between the frame and the second location, the module is moved away from the backing roll for facilitating removal and installation of the felt.

When the link means are selectively disconnected from the second location and the positioning means is in a third disposition thereof, the module is suspended by the positioning means for facilitating removal and installation of the bearing blanket.

When the positioning means is selectively disconnected from the first location, removal and installation of the module is facilitated.

When the positioning means is in the second disposition thereof, and the link means extend between the frame and the second location with the felt already removed, removal and installation of the backing roll is facilitated.

Many modifications and variations of the present invention will be readily apparent for those skilled in the art by a consideration of the detailed description contained hereinafter, taken in conjunction with the annexed drawings. However, such modifications and variations fall with the spirit and scope of the present invention as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side-elevational view of a press apparatus according to the present invention with the positioning means disposed in a first disposition thereof;

Figure 1 A is a side-elevational view of another embodiment of the present invention which includes a hydrostatic press shoe;

Figure 2 is a similar view to that shown in figure 1 , but shows the positioning means in a second disposition thereof;

Figure 3 is a similar view to that shown in figure 1 , but shows the positioning means in a third disposition thereof;

Figure 4 is a similar view to that shown in figure 1 , but shows the module being removed;

Figure 5 is a similar view to that shown in figure 1 , but shows the backing roll being removed subsequent to the removal of the press felt; and

Figure 6 is a side-elevational view of the apparatus shown in figure 1 but viewed from the opposite side.

Similar reference characters refer to similar parts throughout the various views of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

Figures 1 -5 are side-elevational views of a press apparatus generally designated 1 0 for a papermaking machine for pressing a web 1 2.

As shown in figure 1 , the press apparatus 10 includes a frame 14 and an extended nip module generally designated 1 6 which is removably connected to the frame 14.

A backing roll 18 is disposed beneath the module 1 6 and is removably connected to the frame 14. The backing roll 1 8 cooperates with the module 1 6 for defining therebetween an elongate press nip 20 for the passage therethrough of the web 1 2.

A felt 22, which is a press felt, extends through the press nip 20 for receiving water ejected or removed from the web 1 2 during passage of the web 1 2 and felt 22 therethrough.

A looped bearing blanket 24 which may be a smooth surfaced blanket or a grooved or blind drilled blanket extends around the module 1 6. The arrangement is such that the blanket 24 is disposed between the module 1 6 and the felt 22 during passage of the blanket 24 through the press nip 20.

Positioning means generally designated 26 are disposed above the module 1 6 and are selectively connected to the module 1 6 adjacent to a first location 28. The positioning means 26 when connected to the module 1 6 as shown particularly in figure 1 , permits movement of the module away from the backing roll 18.

Link means generally designated 30 selectively extend between the frame 14 and a second location 32 adjacent the module 1 6. The first and second locations 28 and 32, respectively are spaced relative to each other, as shown in figure 1 .

The arrangement is such that when the positioning means 26 is connected to the module 1 6 and in a first disposition thereof as shown in figure 1 , and the link means 30 extend between the frame 14 and the second location 32 as shown in figure 1 , the module 16 is urged towards the backing roll 1 8 for defining therebetween the press nip 20.

As shown in figure 2, when the positioning means 26 is in a second disposition thereof, as shown in figure 2, and when the link means 30 extend between the frame 14 and the second location 32 as shown in figure 2, the module 1 6 is moved away from the backing roll 1 8 for facilitating removal and installation of the press felt 22. Figure 2 shows the felt 22 already removed.

As shown in figure 3, when the link means 30 are selectively disconnected from the second location 32 as shown in figure 3 and when the positioning means 26 is in a third disposition thereof as shown in figure 3, the module 1 6 is suspended by the positioning means 26 for facilitating removal and installation of the bearing blanket 24.

As shown in figure 4, when the positioning means 26 is selectively disconnected from the first location 28 as shown in figure 4 and the link means 30 are disconnected from the module 1 6 as shown in figure 4, removal and installation of the module 1 6 is facilitated.

As shown in figure 5, when the positioning means 26 is in the second disposition thereof as shown in figures 5 and 2, and the link means 30 extend between the frame 1 4 and the second location 32 as shown in figures 5 and 2, but with the felt 22 removed as shown in figure 5, removal and installation of the backing roll 1 8 is facilitated.

In a more specific embodiment of the present invention, the extended nip module 16 includes an elongate press shoe 34.

In an alternative embodiment of the present invention, as shown in figure 1 A, the extended nip module 1 6A includes a hydrostatic shoe 34A.

As shown in figures 1 and 6, the backing roll 1 8 includes a first and a second bearing journal 36 and 38, respectively, which are spaced relative to each other in a cross-machine direction. Figure 6 is a side-elevational view of the press apparatus 1 0 of the present invention but viewed from the opposite side relative to figure 1 .

More specifically, a first and second bearing housing 40 and 42, respectively rotably receive therein the first and second bearing journals 36 and 38.

The first bearing housing 40 includes a further bearing housing 44.

Also, the second bearing housing 42 includes a support 46 as shown in figure 6.

A felt roll 48 extends between the further bearing housing 44 and the support 46. The arrangement is such that the felt roll 48 is rotatably

supported by the further bearing housing 44 and the support 46 for guiding the felt 22.

The felt 22 is disposed between the bearing blanket 24 and the web 1 2.

The bearing blanket 24 in a specific embodiment of the present invention is an enclosed blanket such that lubricating oil for lubricating movement of the blanket relative to the press shoe is contained within the enclosed blanket 50.

As is well-known in the art, the bearing blanket 24 may be a vented blanket including grooves or blind-drilled holes.

The positioning means 26 includes a double acting hydraulic cylinder 52 which is connected to a source of hydraulic pressure 54 as shown in figure 1 .

More specifically, the positioning means 26 as shown in figures 1 and 6 includes a first and second hydraulic cylinder 52 and 58, respectively. The first cylinder 52 has a first and second end 60 and 62, respectively.

The second cylinder 58 has a first and a second extremity 64 and 66, respectively. The arrangement is such that the first end 60 and the first extremity 64 are rotatably connected to the frame 1 4. The second end 62 and the second extremity 66 are selectively connected to the module 1 6 adjacent to the first location 28.

During removal and installation of the blanket 24, the second end 62 is disconnected from the first location 28.

During removal and installation of the module 1 6, both the first and second end 62 and the second extremity 66 are disconnected from the first location 28.

The link means 30 include a first and second link 68 and 70. The first link 68 has a first and second end 72 and 74. The second link 70 has a first and a second extremity 76 and 78, respectively. The arrangement is such that the first end 72 and the first extremity 76 of the links 68 and 70 are rotatably connected to the frame 14. The second end 74 and the second extremity 78 of the links 68 and 70, respectively are selectively connected to the second location 32.

The second end 74 and the second extremity 78 of the links 68 and 70 when connected to the second location 32 are rotatably connected relative to the second location 32.

The press apparatus as shown in figures 1 and 6 also include a first and a second yoke 80 and 82, respectively.

A guide roll 84 guides the felt 22. The arrangement is such that during removal and installation of the felt 22, the guide roll 84 is disposed within and rotatably supported by the first and the second yoke 80 and 82, thus, reducing the tension of the press felt in order to enable removal and installation thereof.

In operation of the apparatus according to the present invention, prior to closing the nip the vertical cylinders should apply a preload to the

links by applying retrack pressure to the first cylinder stroke. The pressure will be enough to off-set the module weight as well as add some link preload which would be in the range 1000 - 1200 psi.

When the enclosed extended nip press is put in a close mode to stop the press drives, the cylinder retrack pressure should be dropped to around 200 to 300 psi. Such is done in order to ensure that the side support link 30 will always be in compression when the machine is in operation. If the cylinder pressure remains at the high pressure, that is 1000 - 1 200 psi range, the side support links 30 may toggle between tension and compression depending on the drive load, and such would lead to vibration problems.

During the blanket installation or removal operation, a stringer beam not shown supports the front of the module, and in the case of blanket installation, the blanket should be on the stringer beam prior to the stringer beam supporting the front of the module, as is well-known to those skilled in the art.

The present invention provides a unique arrangement for installing or removing components of an inverted extended nip press apparatus.