US3361620A

US3361620A - Deckle assembly for a paper making machine

Info

Publication number: US3361620A
Application number: US417707A
Authority: US
Inventors: Fred J Gedemer
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1964-12-11
Filing date: 1964-12-11
Publication date: 1968-01-02
Anticipated expiration: 1985-01-02

Description

Jan. 2, 1968 F. J. GEDEMER 3,361,620

DECKLE ASSEMBLY FOR A PAPER MAKING MACHINE Filed Dec. 11, 1964 /w mliori United States Patent Office Fatented Jan. 2, 1965 3,361,620 DECKLE ASSEMBLY FOR A RAPER MI SKING MACHINE Fred J. Gedemer, Appleton, Wis assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis. Filed Dec. 11, 1964, Ser. No. 417,707 11 Claims. ((13. 162-353) ABSTRACT OF THE DISCLOSURE A paper machine having a deckle box over each edge of a fourdrinier wire in close proximity to a stock discharge slice opening of a headbox, and each deckle box having a bottom and a pair of laterally spaced side walls cooperating with the bottom to define a passage having an inlet facing the slice opening to collect a portion of paper stock from the edges of a thin layer of stock emerging under a head of pressure from the headbox and divert this portion of stock up a slight incline and away from the wire in a downstream direction.

This invention relates to a paper making machine and in particular that portion of a machine where paper stock is discharged from a headbox through a slice assembly and deposited upon a fourdrinier wire.

The quality of paper along the edges of a web formed on a fourdrinier wire is afl'ected by the pattern of stock flow both within the headbox and on the fourdrinier wire. Within the headbox the friction of stock flow on headbox walls, as well as distributor roll heads and journals, acts to slow the velocity of stock movement along the inner walls of the headbox and tends to produce paper with light edges. To avoid this problem one form of prior art structure provided a drain along each side wall of the headbox to draw oil such slower moving stock before it reached the slice. This solved the problem of light edges but caused a slight lateral cross flow of stock which can continue even after the stock has passed through the slice and is deposited upon the wire. The cross flow of stock causes two problems. A first problem is that with a cross flow stock is taken away from the flow through the middle of the slice. A second problem is that the cross flow continuing beyond the slice strikes ruler deckles (which are walls closely spaced above each edge portion of the wire) and causes a reflected wave back across the stock on the wire. These two problems can be solved but require a careful adjustment of the slice and ruler deckles that slope upwardly away from the wire so such wave energy can be dissipated by the wave rolling up the slope of the deckle. Accordingly, it is an important object of the present invention to eliminate such slow moving edge stock in a new and improved manner without causing stock cross flow with the attendant need for such aforementioned slice adjustment and sloped ruler deckles.

According to the present invention the slower moving edge stock is drawn away from the main body of stock but not until after the stock has passed out of the headbox through the slice. According to a preferred embodiment of the invention a deckle box is provided on each side of the machine. Each deckle box has a bottom, inboard and outboard side walls and a cover defining an enclosed passage having an inlet opening facing the slice. The box bottom rests firmly upon an apron projecting outwardly beneath the slice. The bottom of the box is slightly inclined upwardly in the direction away from the apron so it does not make contact with the upper surface of the rapidly moving fourdrinier wire. Each box has a straight section diverging slightly away from the adjacent outer edge of the wire in a downstream direction and this straight section is long enough to reach from the inlet opening to beyond the supporting structure. At the end of the straight section of box opposite the inlet opening, each box turns sharply outward and away from the fourdrinier wire. The inboard wall and bottom of each box are each contoured at the inlet opening to define a knife edge flush with the outer surfaces thereof and upwardly inclined away from the slice. A small jet air shower may be aimed down the knife edge of the inboard wall to disperse any stock fiber that may collect on this edge. A conventional ruler deckle may engage the inboard wall of each box at the inlet opening and extend parallel to the wire edge and part way along the length of the web forming surface of the wire. The ends of the ruler deckles adjacent the inlet openings are contoured to provide a knife edge flush with the inboard facing surface thereof to provide a smooth surface merging with the inboard wall of each deckle box. Thus each decide box draws off the slower moving edge stock as it flows over the apron downstream of the slice and collects it in an unset condition that can be immediately recirculated back to stock mixing equipment, and this is accomplished without causing any undesirable cross flow conditions within the headbox or on the fourdrinier wire.

.Other objects and how they are attained will appear from the following more detailed description of the invention with reference to the drawings showing a perspective View of a portion of a paper making machine constructed according to the present invention.

Referring now to the drawing, there is shown a fourdrinier wire 10 looped around a breast roll 11 that turns in the direction indicated by an arrow. A portion of a headbox is shown at 12 and the portion shown includes part of a front wall structure 13 with an inclined depending flexible upper lip 14. Part of a headbox bottom structure 15 is shown and this structure includes a lower lip 16 with an apron 17 extending therefrom. A blade 18 is mounted on the lateral edge of upper lip 14 that cooperates with lower lip 16 to define an adjustable slice opening 19. The slice opening 19 is adjusted by means (not shown) connected to upper lip 14- that are operative to bend the flexible upper lip 14 to adjust the slice opening 19.

A deckle box 20 is provided over each lateral edge of wire 1t) and apron 17. Each box 20 has a bottom 21, inboard and outboard walls 22, 23, respectively, and a cover 24 to define an enclosed passage 25 having an inlet opening 26 facing the slice opening 19. The bottom 21 of each box 20 rests firmly upon the apron 17. The bottom 21 is slightly inclined upwardly in the direction away from apron 17 to avoid making contact with the upper surface of the rapidly moving wire 10. Each box has a straight section diverging slightly away from the adjacent outer edge of wire 10 in a manner most easily seen in the upper right hand portion of the drawing, and this straight section may be connected to supporting columns 3t) by means such as bolt assemblies 31. Beyond the supporting columns 3a the boxes 29 turn sharply outward away from the fourdrinier wire 10 and then turn downwardly to discharge to the pit (not shown) beneath wire 19. Other suitable provisions for recirculating stock passing through boxes 20 may, of course, be made as desired.

The inboard wall 22 and bottom 21 of each box 20 are each contoured at the inlet opening 26 to define a knife edge 32, 33 flush with the outer surfaces thereof and upwardly inclined away from the slice 19. A small water or air jet 34 may be aimed down the knife edge 32 of the inboard Wall 22 to disperse any stock fiber that may collect on this edge. A conventional ruler deckle 35 may engage and be fastened to the inboard wall 22 of each box at the inlet opening 26 and extend parallel to the 3 wire edge and part way along the length of the web forming surface of the wire 10. The ends of the ruler deckles 35 remote from box 20 may be fastened to support structure 37. The ends of the ruler deckles 35 adjacent the inlet openings 26 are contoured to provide a knife edge 36 flush with the inboard facing surface thereof to provide a smooth surface merging with the inboard wall 22 of each deckle box 20.

In the operation of the described apparatus, dilute paper stock in headbox 12 passes between upper and lower lips 14, 16 and out through slice 19 to flow over the apron 17 and on to the rapidly moving wire 10. The slower moving portion of the stock flowing along the laterally spaced edges of apron 17 will be directed by the knife edges 32, 33 to flow through inlet opening 26 and into the passage 25 within each deckle box 20. Stock passing between the knife edges 32 Will flow on to the Wire 16 and be carried between the ruler deckles 35 in a conventional manner. However, each deckle box 20 draws oh the slower moving edge stock after it has passed out of the headbox 12 and this stock in a fluid unset condition is collected for recirculation or disposal as may be desired. This stock is drawn off apron 17 without causing any undesirable cross flow conditions within the headbox 20 or on the fourdrinier wire 10. Although the stock is drawn off after emerging from the headbox, it is collected in an unset condition and therefore no added energy is required to break up fibers before recirculating the stock. Further, if it is desired to make paper in a width that is narrower than the maximum for which a machine is designed, the effective width of the wire can be reduced by providing wider decide boxes or by placing spacers (not shown) between the box walls 23 and supporting structures such as the columns 30, to move the boxes 20 inwardly from the lateral edges of the screen 10.

From the foregoing it will be understood that the present invention is possessed of unique advantages. However, such modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included within the scope of this invention and thus the scope of this invention is intended to be limited only by the scope of the claims such as are, or may hereafter be, appended hereto.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a paper making machine including a fourdrinier wire and a headbox having a slice arranged to discharge stock from the slice on the wire, support structure along both sides of the wire and extending upwardly thereof, a deckle box over each edge of said wire and connected to said support structure, each deckle box comprising a bottom and a pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice, and each said box having a section diverging away from the adjacent edge of said wire in a downstream direction to divert the portion of paper stock collected through said inlet from the edges of the thin layer of stock emerging from the slice opening of said headbox.

2. In a paper making machine including a fourdrinier wire and a headbox having an apron and a slice arranged to discharge stock from the slice over the apron and onto the'wire, support structure along both sides of the wire and apron and extending upwardly thereof, and a vertical ruler deckle parallel to and spaced inwardly of each edge of the wire with one end thereof on said apron and the opposite end connected to said support structure, a deckle box over each edge of said wire outboard of said ruler deckle and connected to said support structure, each deckle box comprising a bottom resting upon said apron downstream of the slice and a pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice, and each said box having a section diverging away from the adjacent ruler deckle in a downstream direction to divert the portion of paper stock collected through said inlet from the edges of the thin layer of stock emerging from the slice opening of said headbox.

3. In a paper making machine including a fourdrinier wire and a headbox having a slice arranged to discharge stock from the slice onto the wire, support structure along both sides of the wire and apron and extending upwardly thereof, a deckle box over each edge of said wire and connected to said support structure, each deckle box comprising a bottom and a pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice, the inboard sidewall and bottom of each box defining a knife edge flush with the external surfaces of said box, and each said box having a section diverging away from the adjacent edge of the wire in a downstream direction to divert the portion of paper stock collected through said inlet from the edges of the thin layer of stock emerging from the slice opening of saidheadbox.

4. In a paper making machine including a fourdrinier wire and a headbox having a slice arranged to discharge stock from the slice onto the wire, support structure along both sides of the wire and apron and extending upwardly thereof, a deckle box over each edge of said wire and connected to said support structure, each deckle box comprising a bottom and a pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice with a perimeter sloped upwardly and away from said slice, the inboard sidewall and bottom of each box defining a knife edge flush with the external surfaces of said box, and each said box having a section diverging away from the adjacent edge of the wire in a downstream direction to divert the portion of paper stock collected through said inlet from the edges of the thin layer of stock emerging from the slice opening of said headbox.

S. In a paper making machine including a fourdrinier wire and a headbox having an apron and a slice arranged to discharge stock from the slice over the apron and onto the wire, support structure along both sides of the wire and apron and extending upwardly thereof, and a vertical ruler deckle parallel to and spaced inwardly of each edge of the wire with one end thereof on said apron and the opposite end connected to said support structure, a deckle box over each edge of said wire outboard of said ruler deckle and connected to said support structure, each deckle box comprising a bottom resting upon said apron downstream of the slice and a pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice with a perimeter sloped upwardly and away from said slice, the inboard sidewall and bottom of each box defining a knife edge flush with the external surfaces of said box, and each said box having a section beginning at said inlet diverging away from the adjacent ruler deckle in a downstream direction to position the knife edge on the inboard wall in a common vertical plane with the inboard vertical surface of said adjacent ruler deckle.

6. In a paper making machine including a fourdrinier wire and a headbox having an apron and a slide arranged to discharge stock from the slice over the apron and onto the wire, support structure along both sides of the wire and apron and extending upwardly thereof, and a vertical ruler deckle parallel to and spaced inwardly of each edge of the wire with one end thereof on said apron and the opposite end connected to said support structure, a deckle box over each edge of said wire outboard of said ruler deckle and connected to said support structure, each deckle box comprising a bottom resting upon said apron downstream of the slice and sloping upwardly in a downstream direction, anda pair of laterally spaced sidewalls cooperating with said bottom to define a passage having an inlet opening facing said slice with a perimeter sloped upwardly and away from said slice, the inboard sidewall and bottom of each box defining a knife edge flush with the external surfaces of said box, and each said box having a section beginning at said inlet diverging away from the adjacent ruler deckle in a downstream direction to position the knife edge on the inboard wall in a common vertical plane with the inboard vertical surface of said adjacent ruler deckle.

7. A deckle box for diverting and collecting a portion of paper stock along an edge of a thin layer emerging from the slice opening of a headbox, the deckle box comprising a bottom and a pair of laterally spaced sidewalls defining a passage having an inlet opening, at least one of said sidewalls defining a knife edge flush with the external surfaces thereof to divert a flow over said edges inwardly of the perimeter of said inlet.

8. A deckle box for diverting and collecting a portion of paper stock along an edge of a thin layer emerging from the slice opening of a headbox, the deckle box comprising a bottom and a pair of laterally spaced sidewalls defining a passage having an inlet opening, at least one of said sidewalls and said bottom each defining a knife edge flush with the external surfaces thereof to divert a flow over said edges inwardly of the perimeter of said inlet.

9. A deckle box for diverting and collecting a portion of paper stock along an edge of a thin layer emerging from the slice opening of a headbox, the deckle box comprising a bottom and a pair of laterally spaced sidewalls defining a passage having an inlet opening with a perimeter sloped upwardly toward a portion of said passage remote from said inlet, at least one of said sidewalls and said bottom each defining a knife edge flush with the external surfaces thereof to divert a flow over said edges inwardly of the perimeter of said inlet.

11). A deckle box for diverting and collecting a portion of paper stock along an edge of a thin layer emerging from the slice opening of a headbox, the deckle box comprising a bottom and a pair of laterally spaced sidewalls defining a passage having an inlet opening, one of said side walls defining a knife edge flush with the external surfaces thereof to divert a flow over said edges inwardly of the perimeter of said inlet, and said box having a section that diverges away from the side of said box having a sidewall defining a knife edge.

11. A deckle box for diverting and collecting a portion of paper stock along an edge of a thin layer emerging from the slice opening of a headbox, the deckle box comprising a bottom and a pair of laterally spaced sidewalls defining a passage having an inlet opening with a perimeter sloped upwardly toward a portion of said passage remote from said inlet, one of said sidewalls and said bottom each defining a knife edge flush with the external surfaces thereof to divert a flow over said edges inwardly of the perimeter of said inlet, and said box having a section beginning at said inlet that diverges away from the side of said box having a sidewall defining a knife edge.

References Cited UNITED STATES PATENTS 1,734,929 11/1929 Vedder 162-353 X DONALL H. SYLVESTER, Primary Examiner. S. LEON BASHORE, Examiner. A. C. HODGSON, Assistant Examiner.