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Патент USA US3082829

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March 26, 1963
E. J. JUSTUS ETAL
3,032,319
BELT GUIDING MEANS FOR SUCTION BOXES
Filed Jan. 50. 1961
3 Sheets-Sheet 1
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March 26, 1963
E. J. JUSTUS ETAL
3,082,819
BELT GUIDING MEANS FOR SUCTION BOXES
Filed Jan. 50. 1961
5 Sheets-Sheet 2
42
225
IN VEN TORS
[djrar f. Jujz‘us
BY Penn (5 6 ran in
March 26, 1963
E. J. JUSTUS ETAL
3,082,819
‘ BELT GUIDING MEANS FOR SUCTION BOXES
Filed Jan- 60, 1961
5 Sheets-Sheet 3
31
INVENTORS
[ajyar ffzzsl‘u:
I
5’
BY Penn 1': C [rarzz'n
A
ORNEYS
United States Patent
[ice
1
3,682,819
BELT GUlDlNG MEANS FOR SUCTION EQXES
Edgar J. Justus and Dennis C. Cronin, Beloit, Wis, as
signors to Beloit Iron Works, Beioit, Wis, a corpora
tion of Wisconsin
.
Fiied Jan. 30, 1961, Ser. No. 85,664
8 Claims. (Cl. 162--34-§)
3,082,819
Patented Mar. 26, 1953
2
?rst and second guide means, the ?rst guide means pre
senting a curved surface abutting the oncoming side of
the suction box and having a radius such that the belt is
properly tensioned and smoothly transcends from the
curved surface onto the suction box top without rising
therefrom, and the second guide means presenting a
lcurvate surface contoured to restrain or con?ne the belt
or looped carrier band to a symmetrical shape so that the
belt during travel conforms to its natural curvature in an
The present invention relates broadly to the paper
making and related arts, and is more particularly con 10 untensioned state.
The ?rst guide means, and which are particularly effec
cerned with new and improved means having especial
tive in eliminating the noted belt ?exure problem upon
utility in the guiding of a moving belt traveling in sup
entry onto the suction box top, desirably take the form
porting contact with a forming wire over a suction box
of a header member ‘having a precisely contoured belt
in the Fourdrinier type paper machine.
As is well known, the conventional Fourdrinier type 15 receiving surface. In most applications a header member
is utilized at both the oncoming and off-running sides of
paper machine comprises a looped traveling forming
the suction box, extend substantially entirely across the
wire presenting a forming reach extending from a breast
width of the belt, and are passed to supply fluid to per
roll, at which the stock is ?owed onto the wire, to a suc—
tion couch roll located approximately at the station at
which the formed web is removed from the wire. Various
de-watering devices are mounted beneath this reach of the
forming ‘wire, and one common dewatering device is
known as a suction box and presents a flat perforate top to
forations in the suction box cover to lubricate the under
side of the belt during travel thereover. The radius of the
belt receiving surface on the oncoming guide means is
precisely controlled, since if the radius is too large the
belt is unduly tensioned, whereas if the radius is too small
the belt does not smoothly transcend or enter upon the
the bottom side of the wire. The interior of the suction
box is exhausted to assist in drawing water from the web 25 suction box cover, with the result that the belt ?exes in
through the wire and through the perforations in the ?at
the manner earlier noted.
The second guide means, on the other hand, in an ex
top of the suction box. The pressure differential which is
thereby created tends to hold the traveling wire down
emplary embodiment of the invention comprises an arcu
against the stationary ?at top of the suction box, resulting
ate plate member suitably attached along the underside
of the suction box and assures effective guidance and
in increased wear on the wire.
wire over fixed suction boxes, ‘and vone known structure
positioning of the belt so that each element of the belt
travels through the same angular distance during one
revolution. The second guide means can, however, be
takes the form of a perforated moving belt with solid
provided by one or more rolls or rod members within the
Various means have been suggested for the purpose
of avoiding wire wear caused by drawing the moving
edges which is installed between the traveling Fourdrinier 35 belt loop and which also effectively con?ne the belt so
that its shape constantly during each revolution is sym
wire and the suction box covers. However. largely as a
metrical and conforms to its natural curvature when in
result of the inherent stiffness in the belt and pull thereon
as the belt reverses its direction of travel, combined with
suction forces on the belt, the belt will ?ex or whip up
a relaxed or untensioned state. The second guide means
wardly at the oncoming side of the suction box. Numer
ous disadvantages result from this action. First, ?ber
formation is disrupted by the forces applied by the belt
in its ?exed state and by introducing air between the belt
:and suction box top, causing uneven drainage. Second,
further be equipped with tension control capabilities by
the ?exing often causes the belt to travel unevenly across
the suction box cover, so that the belt is in e?ect skewed,
with the result that the belt edges may rub against the
guides on the cover and cause belt damage. Third, both
the belt and the suction box cover have perforations there
after.
It is accordingly an important aim of the present inven
tion to provide an improved paper machine, and more
particularly, to provide novel means for guiding the mov
ing belt traveling about a suction box in a Fourdrinier type
paper machine.
in which periodically align themselves during travel of
the belt over the cover.
If the belt does not travel in a
straight line path along the cover, the respective holes in
the belt and cover do not align themselves and poor de
watering of the web results.
In addition, and also the cause of the last-named Ob‘.
jection of uneven belt travel, is a difference in the rela 55
tive peripheral lengths of the belt on opposite sides thereof
if provided by roll or rod means within the belt loop may
utilization of ‘means for shifting the guide roll vertically
or horizontally about the axis thereof. Other features of
the ?rst and second guide means will be noted in con
nection with the detailed description appearing herein
Another object of this invention lies in the provision of
guide members positioned at the oncoming and off-run
ning sides of a suction box which effectively prevent ?ex
ing of the belt at the oncoming side to prevent disruption
of ?ber formation, belt damage and ineffective web de
watering.
Still another object of this invention is to provide guide
resulting from unavoidable errors in belt manufacture.
means located generally beneath the suction box and
While a difference of %4 of an inch in a belt having an
which con?ne the belt to a symmetrical shape by a re
inner circumferential length of ?fteen feet may seem at
straining action so that each element of the belt travels
?rst insigni?cant, the mere fact that one side is relatively 60 through the same angular distance during one revolution
longer than the other side causes the short side to lead
about the suction box.
and the long side to lag. This effect is cumulative during
A further object of the instant invention lies in the
continuous belt travel, and ultimately the belt becomes
provision of a paper machine including a suction box re
skewed relative to the 2longitudinal centerline of the suc
ceiving thereover an endless ?exible belt or looped carrier
tion box top. Again, the drain perforations in the belt 65 in supporting contact with a traveling forming wire or
and cover become misaligned, resulting in poor dewater
drain band, and which paper machine embodies the im
ing and even a seizing of the belt to the cover.
provement of ‘?rst guide means providing a curved sur
face at the oncoming side of the suction box and having
a radius such that the belt is properly tensioned and
70
smoothly transcends onto the top of the suction box with
difficulties. In accordance with the present teachings, the
out rising therefrom, and second guide means within the
belt is guided during its travel about the suction box by
The instant invention resides in a novel, simple and
particularly effective arrangement for overcoming these
3,082,819
9
loop of the endless belt and having a curvature such that
the belt conforms substantially to its natural curvature
in an untensioned state.
Other objects and advantages of the invention will be
come more apparent during the course of the following
description, particularly when taken in connection with the
accompanying drawings.
In the drawings, wherein like numerals designate like
41
ment, the ?rst guide means 23 and 24 assume a somewhat
different contour in the lower portions thereof.
The illustrative form of suction box designated at 14
in FIGURE 2 comprises a generally rectangular trough
like body portion 30 having opposed side walls 31 and 32
integrally connected to a bottom wall 34, and removable
end walls 33, one only of Which is shown. The open top
of the suction box body portion 30 mounts thereon a cover
member 35, the drain perforations and fluid supply pas
parts throughout the same:
FIGURE 1 is an essentially diagrammatic elevational 10 sages of which will be later described in connection with
succeeding views of the drawings.
view of a paper machine embodying web dewatering ap
T0 provide an effective seal between the end walls 33
paratus constructed in accordance with the principles of
and the body portion 30 of the suction box 14, and to
this invention;
provide a convenient mounting of the end walls to the
FIGURE 2 is an enlarged view of the web dewatering
apparatus of FIGURE 1, and showing more particularly 15 body portion, the side walls 31 and 32 and bottom wall
34 may mount thereon ?ange means 35 having bolt re
?rst and second guide means connected thereto;
ceiving openings 36a therein. Gasket means (not shown)
FIGURE 3 is an enlarged sectional fragmentary detail
are located between the ?ange means 36 and opposed end
view taken substantially along the line "III—III of FIG
walls 33, ‘and the end walls are equipped with mating
URE 2;
‘FIGURE 4 is a fragmentary detail end view of one 20 openings for receiving bolt means or the like threaded
into the openings 36a.
form of ?rst guide means to prevent belt ?exing, and
To rigidify the suction box 14 ‘and to provide a sup
showing further therein means for supplying liquid from
plemental mode of attachment of the cover 35 thereto‘
the interior of the guide means to conduit means on the
each end wall 33 adjacent the upper end thereof has
underside of the suction box top to lubricate the belt
25 Welded or otherwise secured thereto longitudinally extend
traveling thereover;
ing beam members 37 of a length generally coextensive
FIGURE 5 is a fragmentary top plan view of the form
ing wire, supporting looped belt and suction box cover,
and illustrating particularly proper alignment of perfora
tions in the belt with perforations in the suction box cover
when the belt is traveling properly thereover;
‘FIGURE 6 is a view similar to FIGURE 5, but show
ing misalignment of the belt and cover perforations when
the belt is skewed as a result of the shorter side thereof
leading the longer side;
with :the length of the end walls.
Cooperating with the
beam members 37 to conveniently support the cover 35
is ‘a second pair of beam members 38, each having longi
30 tudinally spaced openings 38a therein threadably receiv
ing screw means 39. The screw means 39 may be of the
same character employed to attach the cover member 35
to ?uid supply conduit means in a manner to be later
hereinafter described. In any event, it may be seen that
‘FIGURE 7 is a fragmentary detail view, with parts 35 the plate member 35 has a plurality of mating counter
sunk openings 49 therein so that the heads of the screw
thereof in section, and illustrating one manner of attach
means is recessed in the cover member 35. As well, as
ing the second guide means to the underside of the suction
is shown in FIGURE 2, opposed side walls 31 and 32
box; and
of the ‘suction box body portion 30 are recessed at the
yFIGURES 8, 9 and 10 are diagrammatic elevational
upper ends thereof to provide ledge means 31a and 32a
views of other forms of web dewatering apparatus incorpo
to seat opposite sides of the cover member 35.
rating modi?cations to the ?rst and second guide means
Further details of the cover member appear in FIG
therein.
IURE 5, and upon reference thereto in conjunction with
Referring now to the drawings, there is shown in FIG
FIGURE 3 it may be observed that the ?at plate-like
URE 1 a paper machine indicated generally by the refer
cover member 35 is equipped with a plurality of trans
ence numeral 10, and comprising a looped forming wire
versely spaced rows of drainage openings or perforations
11 trained over a breast roll 12, table rolls 13, suction
42 running and spaced longitudinally in the direction of
box 14, couch roll 15, a turning roll 16, and return rolls
wire travel indicated by the arrow 43. The perforations
17. Stock is deposited on the upper wire run 11a from
a head box 18 onto a forming board 19 in the region of
42 open into the interior of the suction box 14, and
the breast roll 12, and the stock is dewatered during its 50 conveniently the opposed end walls 33 of the box may
travel on the upper wire run 1111 to form a web W which
be passaged at 33a to receive branch conduits 64a and
is removed from the wire 11 by a pickup felt 29 urged
6412 connected ‘as is shown diagrammatically to a main
against the web W by a suction pickup roll 21. A rotary
conduit 65 leading to exhaust means in the form of a
pump 44.
belt 22 is driven by the forming wire 11 about the suc
t'ion box 14 and is guided during its travel by ?rst guide 55
As is shown in the cut-out portion of FIGURE 5, the
means 23 and 24 and second guide means 25, the struc
suction box top or cover 35 has land areas 45 inter
tural features of which will be later dealt with in detail.
mediate the perforations 42 and providing a lubricant
The present invention is directed to guide means 23—25
receiving surface whereby the traveling belt 22 is carried
for preventing skewing of a rotary elastomeric belt 22
by a ?uid ?lm during ‘travel along the suction box cover.
in association with a suction box in a Fourdrinier type 60 The land areas 45 between the rows of perforations 42
paper machine, as is shown in FIGURE 1. The struc
‘are apertured as at 46 in countersunk con?guration (to
tural details of the suction box 14 and traveling belt 22
receive therein passaged attaching means 47 threadably
form no part of the instant invention, and only such de
connecting the cover member 35 to roof portion 50a
tails thereof are illustrated as are required for a clear
of conduit means 50, further details of which will be
understanding of the present invention. Accordingly, it
later noted. The passages or perforations 46 extend from
will be appreciated that other moving belts and stationary
near the off-running edge of the suction box cover 35
suction boxes may be substituted in lieu of the structures
to near the oncoming edge, and in common with the land
shown, and other changes made to various other portions
areas 45 ‘and perforations 42, extend longitudinally in the
of the paper machine 10. As well, and as will be brought
direction of wire travel.
out in the descriptive material appearing hereinafter, the
There will be later described the structural features
?rst guide means 23 and 24 and ‘second guide means 25
of the ?rst guide means 23 and 24, which desirably also
are susceptible to numerous variations, and further, While
function ‘as ?uid supply headers to the conduit means
in FIGURES l and 2 the rotary belt 22 is driven by the
55}, however, it should be emphasized at the present
forming wire 11, one or more drive rolls can be utilized
moment that water ?ows upwardly in and outwardly
within the loop of the endless belt, and in such an arrange 75 from the passaged attaching means 47 in generally the
3,082,819
5
6
manner indicated by the arrows 48 in FIGURE 5. The
water ?ows in the directions indicated along the land areas
45 and ultimately to the drain perforations 4-2. The flow
as illustrated in FIGURE 5 is very slight and is con
trolled by the pressure of the belt 22 against the land areas
45, however, the ?ow is su?icient to lubricate the rubber
belt 21 and to prevent dragging thereof over the dry
It was noted in the introductory material hereto that
largely as a result of the inherent stiffness in the belt 22
and pull thereon as the belt reverses its direction of
‘travel, combined with suction forces on the belt, the belt
will flex or whip upwardly at the oncoming side of the
suction box 14}. This action disrupts ?ber formation by
the forces applied to the belt in its flexed state and by
introducing air between the belt and suction box top 35,
causing uneven drainage. Also, the ?exing often causes
land areas 45, when belt skewing is prevented by the
second guide means 25.
The belt 22 is provided with perforations or drainage 10 the belt to travel unevenly across the suction box cover,
holes 22a, as indicated in FIGURES 3 and 5, and said
so that the belt in effect is skewed, with the result that
holes are so located in the traveling belt that they do
the belt edges may rub against the guide means 49‘ and
not align themselves with the passages in the attaching
cause belt damage. In addition, it is essential for effec
tive operation that the belt drainage perforations 22m and
cover drain perforations 42 periodically align themselves
screw means 4-7 communicating with the conduit means
50.
In this way, water is not forced back up through
the ‘drainage holes 22a. Instead, the drainage holes pe
riodically align themselves with the perforations 42 in
during travel of the belt 22 over the cover. If the belt
does not travel in a straight line path along the cover,
the respective holes in the belt and cover do not align
the suction box cover 35. The bottom side of the belt
21 has, of course, a number of openings therein formed
themselves and poor dewatering of the web W results.
by the drainage holes 22w. Intermediate said drainage
As well, if the belt becomes skewed relative to the suc
tion box cover 35, the belt land areas 22b may locate
holes there are land areas 22b on the bottom side of the
belt which cover the passages in the screw means 47.
themselves over the cover perforations 42, causing the
These belt land areas 22b are urged downwardly against
belt to seize upon the cover 315.
the suction box land areas 45 by the pressure differential
In accordance with the present inventive concepts, belt
created by the suction box 14. For this reason, water 25 flexing and ‘the stated problems resulting therefrom are
is urged into the passaged screw means 47 under slight
eliminated by provision of a ?rst guide means 23' having
pressure to e?ect continuous seepage of water between
a belt engaging surface 23a contoured or shaped from
the faces of the land areas 22b and 45, this seepage being
necessary to prevent the rubber belt 22 from wiping the
land areas 45 dry, and thereby increasing the frictional
drag. Preferably, the seepage of water is very slight so
essentially the line of belt engagement (designated at “x”
in FIGURE 4) to the line of entry of the belt onto the
box structure (identi?ed at “y” in the same view) such
that the belt 22 is properly tensioned and smoothly tran
scends from the curved surface 23a onto the suction box
top 35 without rising therefrom. The other ?rst guide
as not to overload the water removal system for the
suction box 14.
The top side of the belt 22 is provided with a plurality
means Z-‘t- at the off-running side of the suction box 14
of longitudinally spaced laterally extending grooves or 35 is desirably identically shaped for substantially the same
channels 220, one of which is shown in FIGURE 3. Each
such groove 22c is provided with one or more of the
drainage holes 22a, which as earlier noted, periodically
communicate with the perforations ~42 in the suction box
cover 35.
.
The conduit means se for supplying ?uid through the
40
reasons, although it is at the oncoming side of the box
that the entry problem exists, and accordingly, 9. some
what differently shaped guide 24 may be utilized, as will
be hereinafter noted.
Extensive investigations have demonstrated that the
belt engaging surface 23a has a critical radius. Thus, if
the radius is too large, an undue amount of tension is
applied to the belt 22 and excessive belt drag over the
passaged screw means 47 includes a roof portion "Ella
threadably receiving the attachment means 47 and a chan
cover 35 results. While too large a radius on the belt
nel portion Sll‘b ‘welded or otherwise secured ‘to the roof
portion Ella. The conduit means are transversely spaced 45 engaging surface 23a does not apparently interfere with
attainment of proper entry onto the cover and is thereby
and longitudinally extending, and one mode of attaching
effective to eliminate belt ?exing, a radius too low for
the conduit means to the suction box wall structure is
the surface 23a frequently produces belt ?exing. In the
illustrated in FIGURE 4. As appears therein, the chan
latter case of too small a radius, there is not, on the other
nel portion Stlb of each conduit member 5t} may be
seated upon transversely extending shelf members 51 suit
hand, apparently any undue tension forces applied to the
belt 22'.
It has been noted that the critical radius for the belt
engaging surface 23a extends from the points x and y
in FlGURE 4, the latter point being seen to be some
received in the rigid bushinx7 5c‘ is passaged bolt means 57 55 what upstream of the line of abutment of the guide
having an opening 57a extending therethrough. Each
means 23‘ with the suction box end wall 3-1. The portion
from the point y on the belt engaging surface downstream
bolt member 57 is threaded into the side walls 311 and
to ‘the end wall 31 is primarily to facilitate connection of
32 of the body portion of the suction box, as well as into
the guide means 23' to the end wall 31, and the radius in
the bushing ‘56. In this manner, the conduits 50 are
ably secured to opposed side walls 31 and 32 of the suc
tion box 14. Further, at opposite ends of each conduit
member and interiorly thereof there may be welded or
otherwise attached an apertured bushing 56. Threadably
?rmly attached to the opposed side walls 31 and 32, pro 60 this relatively small portion is not particularly critical.
vide support for the suction box cover 35, rigidify the
It has, however, been emphasized that the radius between
cover, and provide an e?ective ?uid supply means for
the points x and y is critical, and while it might be as
the passaged threaded fasteners 47 connecting the cover
sumed that only a single radius measured from the point
z in FIGURE 4 to a point midway between the points
35 to the conduit members 50. As is now apparent, the
passaged screw means 57 may take the same form as the
screw means 3? and 47.
As appears in FIGURE 3, the suction box cover 35
adjacent opposite ends thereof may mount belt guide
x and y is involved, actually there are two radii which
must be controlled to overcome the entry and tensioniug
problems mentioned. Thus, a line struck from the point
a on the suction box end wall 31, and generally midway
means 49, which may take the form of an angle member
of the height of this wall, to the point b on the belt en
secured to the cover 35 by screw means 49a. The guide 70 gaging surface produces what may be regarded as a
means 49 may be spaced along the length of the suc
“tension control portion” 23a-1 and an “entry control
tion box cover 35 or run continuously therea-long, but in
portion” 23a—2. Exemplary radii for these two portions
will be noted in the next paragraph, although it is believed
any event, the guide means 49' prevent excessive lateral
shifting of the belt 22 during travel along the suction
now apparent that if the radius of the tension control
box cover 35‘.
75 portion 2311-1 as measured between the points x and b
3,082,819
8
is too large, undue belt tensioning will result. On the
other hand, if the radius for the entry control portion
somewhat exaggerated form the belt skewing problem.
Like numerals from FIGURE 5 have been applied thereto,
23a-2 ‘and measured from the point b to the point e is
and in FIGURE 6 the relatively shorter side of the belt
is designated as 22s and the relatively longer side as 221.
too small, belt ?exing or whipping will likely result. It
may accordingly be observed that the guide means 23 CR It can be noted therefrom that when the rubber belt 22
in accordance with this invention has a belt engaging sur
is moving over the suction box cover 35 in the direction
face 23a comprised of two curved connected portions
23a-1 and 23a—2 having radii such that undue belt ten
indicated by the arrow 43, and belt skewing occurs
either from belt ?exing at the oncoming side of the suc~
:sion is prevented and the belt 22 smoothly transcends on
to the suction box cover 35.
tion box 14 or by reason of unavoidable errors in manu
10 facture causing the belt side 22: to be relatively shorter
It has been found in practice that the radii discussed,
than the belt side 22!, certain of the drain perforations
22a in the belt 22 do not align themselves with the drain
ables are generally the length of the suction box 14,
openings 42 in the suction box cover 35. Accordingly,
the length of the rotary belt 22 and the physical properties
in those areas where the desired hole alignment does not
of the belt. Among the physical properties which must be 15 occur, poor dewatering of the web W can be anticipated.
considered are the belt stiffness, type of grooving 22c
In addition, it is to be further observed from FIGURE 6
therein, type of punching 22a therein, type of reinforcing,
that in those areas where alignment of the belt perfora
one or both, depend upon certain variables. These vari
belt thickness and rubber hardness.
As a speci?c ex
tions 22a and cover perforations 42 do not occur, the
ample, proper belt tension and entry were achieved when
belt land areas 22b cover either partially or completely
the radius of the tension control portion 23a-1 of the 20 certain of the cover drain perforations 42. Since suction
belt engaging surface 23a, as measured from the point In
is constantly being drawn through the perforations 42 to
along the reference line m—n was approximately three
the interior of the suction box 14, it can readily be
inches, and the radius of the entry control portion 2311-2
appreciated that belt seizure may occur, and at least ex
measured from the point a along the reference line a--b
cessive belt drag will take place.
was ?xe inches, when the overall length of the suction
However, the noted problem of belt skewing by rea
box 14 was about 32% inches and the inside circum
son of differences in the belt length on opposite sides
ferential length of the belt 22 was 82 inches. The radii
thereof is essentially entirely eliminated by provision of
mentioned were further achieved with a belt having a
second guide means, constructed as indicated by the nu
thickness of 5/8 inch, grooved and punched as disclosed,
meral 25 in FIGURES 1 and 2, or by use of the means
and being of moderate stiffness and hardness as utilized
to be later described in connection with FIGURES 8, 9
in the art.
and 10. As appears in FIGURES 2 and 7, the second
The one ?rst guide means 23 when constructed as
described not only eliminates belt ?exing upon entry onto
the suction box cover 35 and effectively controls belt
guide means 25 having a curvature such that the belt con
forms substantially to its natural curvature in an unten
sioned state is within the loop of the endless belt 22 gen
tension, but also together with the other ?rst guide means
erally beneath the suction box 14.
24 provides a fluid-tight header to supply a ?uid such as
Water through the passaged screw means 57 into the con
duits 50 and through the passaged screw means 47 to the
underside of the belt 22 to provide the necessary belt
lubrication. Each guide means and header is attached
by welding or related techniques to an adjacent side wall
means 25 comprises a curvate or arcuate belt engaging por
31 or 32 of the suction box body portion 30, and each of
the devices 23 and 24 is provided with opposed end walls
23b and 24b, one only of which is shown. There is in
this manner provided a closed header, and de?ned there
within is a ?uid supply chamber 23c. As appears in FIG
71 (FIGURE 7) welded or otherwise secured to the belt
engaging member 70 and to a generally ?at plate 72
suitably attached to the bottom wall 34 of the suction
URES 2 and 4, one or both of the end walls 23b and
24b of the guide means 23 and 24 is passaged at 23d and
24:1 to provide a connection for ?uid supply conduits 23c
and 242, diagrammatically indicated in FIGURE 2 and I
The second guide
tion 70 essentially coextensive with the width of the belt
22 and having upwardly turned end portions 70a and 79/)
to prevent interference with the travel of the belt 22.
The belt engaging member 70 is desirably rigidi?ed at
transversely spaced locations by arcuate plate members
box body portion 30 and generally coextensive there
with. As also appears in FIGURE 7, the arcuate plate
members 71 at opposite ends of the suction box body
portion may be of somewhat reduced height, as compared
with the arcuate plates intermediate the box ends, in
order to effect a securement of the second guide means
connected to a source of liquid under pressure control
25 to plate means 73 attached by bolt means 74 to the
lable by pump means or the like 62 and 63, also indicated
diagrammatically. Of course the conduits 23c and 242
bottom Wall 34 of the suction box at locations spaced
may be connected to a common line under control of a
nection between the arcuate belt engaging member 70 and
longitudinally therealong. As well, to rigidify the con
single pump, and valve means (not shown) would nor
the plate means 73 bracket means 75 and 76 are provided.
mally be employed in the manner customary in the art.
Desirably, welding techniques are employed to secure the
Guide means 23 and 24 having the controlled radii
reduced height bracket means 75 to the belt engaging
indicated are effective to prevent belt skewing caused by
member 70 and plate means 73, and a like mode of at
whipping or ?exing of the belt upon entry onto the suc
tachment used to secure the central and relatively greater
tion box cover. However, belts skewing can also be 60 height bracket means 76 to the elements mentioned.
caused by unavoidable errors in belt manufacture, such
The second guide means 25 may be seen from FIGURE
that there are differences in the circumferential length
2 to be in relatively light engagement with the traveling
of the belt on opposite sides thereof. It was stated in the
belt 22 along essentially its entire lower run, and that the
introductory material hereto that in a belt having a cir
belt is unsupported along only a relativeii short distance
cumferential length on the inside thereof of approximately 65 from adjacent the upwardly turned portions 742a and 70b
?fteen feet, a difference in the length on the opposite
of the belt engaging member 7% to the ?rst guide means
sides of the belt may be of the order of %4, of an inch
23 and 24. By provision of the second guide means 25
or more.
While this difference may seem inconsequen
tial, it is of suf?cient magnitude during successive revolu
the belt 22 is con?ned to a symmetrical shape by a re
straining action, or as may otherwise be stated, the belt
tions of the belt to cause the “short” belt side to lead the
is forced to conform to its natural curvature in an un
“long” belt side, until utimately the belt skews relative
to the suction box top, causing misalignment of the drain
perforation 22a in the belt 22 and the drain perforation
tensioned state. By so restraining the lower belt run, the
belt during travel along the suction box cover 35 moves
42 in the suction box cover 35.
This can be seen in FIGURE 6, which portrays in
with its longitudinal centerline aligned with the longitudi
nal centerline of the suction box cover. Thereby, the belt
22 is at all times maintained the desired distance from
3,082,819
10
the guide means 49, there is no scraping of the belt there
against, and the condition portrayed in FIGURE 6 does
not occur, but rather, the belt travels as shown in FIG
URE 5.
that the loose ‘or longer side of the belt will be properly
tensioned to assure even tracking along the suction box
Other forms of guide means can be employed to re
strain the lower belt run and to assure that the belt con
suction box relative to the direction of wire travel so as
to align the belt center with the wire center. This proce
forms substantially to its natural curvature in an unten~
dure can be utilized in the instant invention, although
cover.
It has been the prior practice in the art to shift the
experience to date has demonstrated that the ?rst and
second guide means described renders shifting of the suc
FIGURE 8. The suction box 114- of FIGURE 8 can be 10 tion box unnecessary in the majority of instances.
Various forms of ?rst and second guide means for di
constructed in the manner described in connection with
recting the endless belt along the suction box cover have
FIGURES 2, 3 and 4, and as well, the ?rst guide means
23 and 24 may be constituted as was also previously dis
been shown and described herein, and of course, the in
sioned state. Other forms of the invention are illustrated
in FIGURES 8, 9 and 110‘, reference being ?rst made to
closed. Accordingly, like numerals have been applied
stant invention is susceptible of other changes and modi
thereto.
15 ?cations therein ‘without departing from the novel con
cepts thereof.
In the embodiment of FIGURE 8, there is located with
in the loop of the endless belt 22 and generally beneath
We claim as our invention:
1. In a dewatering apparatus including a suction de~
the suction box 14 a pair of rolls 8t)‘ and 31 which may
or may not be driven. In any event, the lower belt run
vice, a drain band trained thereover, and a looped carrier
is effectively restrained and thereby con?ned to a sym
band supporting the drain band over the suction device,
the improvement of guide means within the loop of the
metrical shape, so that uneven belt tracking does not occur
carrier band generally beneath the suction device and
when opposite sides of the belt are of different circum
ferential lengths. The rolls 8!} and 81 may not be only
having a curvature such that the carrier band conforms
substantially to its curvature in an untensioned state.
two in number, and it is within the contemplation of this
invention that one or more rolls be spaced therebetween. 25
2. In a paper machine which includes a suction box
receiving thereover an endless ?exible belt in supporting
versely in generally parallel relation to opposed side walls
contact with a traveling forming wire, and ?rst guide
means providing a curved surface at the oncoming side
of the suction box 14, effective guiding action is also pro
of the suction box and having a radius such that the
vided when the rolls are diagonally disposed relative to
the direction of belt travel. Under these circumstances, 30 belt is properly tensioned and smoothly transcends onto
adjacent ends of the rolls 8t) and 81 would overlap or be
the top of the suction box Without rising therefrom, the
improvement which comprises second guide means within
relatively close thereto. Further, and as was earlier
the loop of the endless belt having a stationary arcuate
stated, the rolls 80 and 81 may take the form of pipe
means.
surface contacting the belt and restraining the same to
In FIGURE 9 the suction box 14 has the same con 35 con?ne the belt to a symmetrical shape.
?guration, and the ?rst guide means are generally tri~
3. In a paper machine which includes a suction box
receiving thereover an endless ?exible belt in supporting
angularly shaped and are indicated in this view by the
contact with a traveling forming wire, the improvement
numerals 82 and 83. Such guide means, and particularly
which comprises guide means for supporting the belt at
the guide member 82 has a radius calculated to provide
smooth transition for the belt 22 onto the suction box 14 40 the ends of the suction box, at least one of said guide
to prevent belt ?exure.
means providing a complex non-planar surface, said sur
face having lower and upper portions each having a
The embodiment of FIGURE 9 further incorporates
therein rolls 84 and -85 at the oncoming and off-running
different radius of curvature, said lower portion having
In addition, while the rolls 80 and 81 may extend trans
a shorter radius of curvature than the upper portion so
sides of the box, and one or both of these rolls may be
driven to cause belt travel. However, the rolls need not 45 that the belt smoothly transcends along said surface.
be ‘driven, since as earlier indicated the endless belt 22
may be driven in rotation by the forming wire 11. Also
within the belt loop is roll means 86, shown by the arrow
87 applied thereto to be tiltable in a vertical direction in
4. A paper machine in accordance with claim 3 where
in the guide means at both ends of the suction box have
the same shaped surface and each of the surfaces is
shaped with a lower and upper portion of different radii
of curvature with the lower portion having a shorter
order to not only effectively guide the belt 22, but to
radius than the upper portion so that the belt smoothly
vary the tension therein due to differences in the circum
transcends along said surfaces onto the top of the suction
ferential length of the belt on opposite sides thereof. In
box and off of the top of the suction box.
other words, on the relatively shorter side of the belt 22,
5. In a paper machine which includes a suction box
a relatively greater tension would be applied, and this
may be accomplished by bearing structure well known 55 receiving thereover an endless ?exible belt in supporting
contact with a traveling forming wire, the improvement
to the ‘art. The guide and tensioning means 86 may of
which comprises guide means for supporting the belt at
course be responsive to changes in belt tension, and this
the ends of the suction box with at least one of said guide
may be accomplished by having the belt 22 along its lower
means having a complex curved convex continuously
run in contact with suitable detecting means actuating
60 smooth surface shaped so that the belt smoothly tran
valve means and controlling the air supply thereto. The
scends along said surface.
output of the valve means could then be readily fed to
6. A paper machine constructed in accordance with
diaphragm means in control of the bearing means mount
ing the roll 86.
claim 5 wherein the surface of the guide means positioned
ahead of the suction box on the oncoming side thereof
In the embodiment of FIGURE 10, the suction box
14 and ?rst guide means 23 and 24 are constructed as 65 is shaped in accordance with claim 5 being complex
curved and convex so that the belt smoothly transcends
earlier described in connection with FIGURES 2, 3 and
4, and like numerals have accordingly been applied there
to. The second guide means assuring that the belt 22
along the surface and onto the top of the box.
7. In a paper machine which includes a suction box
receiving thereover an endless ?exible belt in supporting
tensioned state takes the form of roll means 88 tiltable 70 contact with a traveling forming wire and ?rst guide
means on the oncoming side of the suction box guiding
horizontally in the directions indicated by the arrow 89‘
applied thereto. The roll means 88 can incorporate gen
the belt onto the top of the box, the improvement which
erally the bearing structure described in connection with
comprises second stationary guide means below the suc
FIGURE 9, and as well, such bearing means may be
tion
box having a non-moving sliding belt-engaging ar
responsive to tension variations in the belt 212., to assure 75 cuate surface for guiding the lower run of the belt.
conforms substantially to its natural curvature in an un
3,082,819
1l
12
8. In a paper machine which includes a suction box
receiving thereover an endless ?exible belt in supporting
contact with a traveling forming wire, the combination
comprising ?rst guide means at the oncoming side of
the suction box having a complex curved convex con-
suction box having a non-moving sliding belt-engaging
arcuate surface for guiding the lower run of the belt.
References Cited in the ?le of this patent
5
tinuously smooth surface shaped so that the belt smoothly
transcends along said surface and onto the top of the
box, and a second stationary guide means below the
UNITED STATES PATENTS
2,981,328
2,981,329
Justus ——————————————— —— APr- 25: 1961
Justus -------------- -- APF- 25) 1961
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