Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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F I E LD OF l'HE _ I NV}J NT I ON
The present invention relates to a paper-making wire
repair kit and, more particularly, to a patch assembly for
patching perforations accidentally made in a paper-making wire or
pulp-dewatering fabric, and to an apparatus for fixing the patch
of the fabric.
9~QOF THE INVENTION
Paper-making wires used for pulp-dewatering nowadays
consist of a woven fabric of fibres of synthetlc resin. Such
~10 wires are liable to become accidentally perforated during use. A
perforated fabric causes defects in the paper made therewith and
must be replaced or repaired. Such wires are very expensive,
since in a paper-making machine, it is not uncommon to find wires
of 90 feet long and between 150 and 140 inches wide, and costing
520,000,00 ~and more. It has ~been tried--but without good
results--to fix a patch onto the perforation of such a ~wire by
means of an adhesive or glue, ;It has been found that the patch
~falls away very qu~ickly with use.
OB~iSC rs - OF THi INVENTION ~ ~
~ It ls the general ob~ect of the present invention to
IX a~ patch on~ a paper-making wire in such a way that the patch
w~ remain attached to~the wire for a long time during use of
the w~ire.~
Another ob~ect of the present invention is to provide a
patch and~the ueans to ix the patch to the wire, so arranged
;that~they only slightly protrude from the pulp-contacting face of
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the wire, so as to produce paper without any defect which could
be caused by the patch, or the means to attach the same to the
wire.
Another object of the present invention is to provide
an apparatus for fixing a patch to a paper-making wire, which is
of simple construction and easy to operate.
SUMMA~Y OF THE _ VENTION
In accordance with the invention, there is provided the
combination of a paper-making, pulp-dewatering wire having a
perforation with a patch covering the perforation, the patch
being applied against the pulp-contacting face of the wire and
covering the perforation and an adjacent portion of the wire
around the perfora~ion, and metallic U-shaped staples e~tending
through the wire and the patch, with the legs bent against said
patch, and the staples disposed around the perforation.
Preferably, the patch is of circular shape and the staples
disposed in a circle around the perforation, with the legs of the
staples outwardly bent and oriented radially of the patch. The
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blght of the staple preferably does not protrude from the
underface of the wire.
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~ Ihe apparatus to fix the patch to the wire by means of
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the staples, comprises a base plate provided with a plurality of
~staple-ejecting plungers, a pusher plate disposed over the base
plate and having a wire-contacting face and through-bores
slidably receiving the plungers; biasing means to move the pusher
plate from a retracted to an advanced position, spaced from said
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base plate, stop means to stop said pusher plate at said advanced
position under the bias of said biasing means; and guide means to
guide the base plate during its movement between said retracted
and advanced position, and wherein the stroke of said pusher
plate from its retracted to its advanced posltion is at least
equal to the length of a staple, such that in said advanced
position, a staple inserted in a through-bore and contacting the
plunger therein, does not protrude from said wire-contacting face
of the pusher platel and in its retracted position, the end of
said plunger is at least flush with said wire-contactlng face.
Preferably, the through-bores have a cross-sectional elongated
shape, conforming to the cross-section of a U-shaped staple to
~positively orient the latter ln the through-bores. Preferably, a
soft pad is arranged to be applied on the patch opposite the
;~ pusher plate to press the latter to its retracted position while
~;compressing the patch on the wire, causing e~ection of the
staples and;insertion of their legs through said wire and patch
~and lnto said pad, thereby causing compression.of the~wire by the
bight of the~staples. ~The legs of the wire are bent outwardly~by
means of suitable tools,
B~IE DE5 PIPI'ION OP l'HE VRAWING5
Figure 1~ is~. an exploded,~ partlal perspective view
showi~ng the paper-making ~ire having a perforation, a patch to
cover said perforati~on~and~the apparatus for~ flxing the patch to
the~wire by~méans of staples;
Flgure 2 is a ~top plan view of the arrangement of
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Figure 1, but without the overlying rubber pad;
Figure 3 is a cross-section taken along llne 3-3 of
Figure 2, with the rubber pad in position, and showing the pusher
plate in advanced position;
E'igure 4 is a view similar to that of ~igure 3, on an
enlarged scale, and showlng the pusher plate in retracted
position, with the staples inserted through the wire and the
patch, and into the pad;
Figure 5 shows the tooling to bend the legs of the
staples outwardly;
Figure 6 is a partial plan view of the wire and patch
in assembled position; and
Figure 7 is a partial cross-section, taken along line
7-7 of Figure 6.
In the drayings, like reference numerals indicate lihe
: elements throughout, ~ :
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DETAILED DESCRI pTroN ~OF THE PREF RRED rEMBODI~MENT
Referrlng to Figures 1, 2, 6, and 7, there is~ shown a ~:
paper-makiny wire, indicated at 10, of conventional c~on~struction.
Such:wires usually cons:ist of a woven fabric of synthetic resin
fibres,;;such as nylon~.~ This wire forms an endless band used in~ :~
F~oudr~in~i~er paper-making machines, in ~ which the :~band: is
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hori~ontal,~or used in~newer ~ypes of paper-making machines, such:
as~the twin wires former in which the pulp coming~fr~om~the head
box~of the: machine as a water suspension, is~squeezed between the
two verticaI runs of the wires, and the pulp is dewatered by exit
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of the' water through the interstices of the fabric. Such paper-
making machines are made, for instance, by BLACK CLAWSON PAPER
MACHINE DIVISION, of Watertown, New York, under the general trade
mark VERTI-FORMA. The face of the wire from which the water
exits, that is the face of the wire opposite the pulp-contActlng
face, is subjected during travel of the wire to a scraping action
effected by stationary blades, called foils, generally made of
ceramic.
It frequently happens during paper-making that such
wires become perforated due, for instance, to the accidental
presence of small metal objects in the head box, or for whatever
othsr reason. Such perforatlons produce defects in the paper
made therefrom. Attempts have been made to try to patch the
- perforations with patches adhering to the wire by meane. of glue
or the like. Such patches are soon dislodged during use of the
wire.
E'igure 1 shows at 12 a perforation made in the wire or
fabric 10. In accordance with the invention, a patch 14 is
applied over the perforation 12. l'his patch may have a
rectangular or square shape, but with rounded corners, and is
preferably of clrcular shape, as shown. This patch is made of a
material similar to that o'f fabric 10, but ~preferably of smaller
thickness. The patch is of sufficient size to overly the area of
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the fabric 10 surrounding the perforation 12 to receive fasteners
dlsposed around the perforation 12.
In accordanc~ wlth the ~nven~lon, such fast-ners
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consist of metallic staples 16, each of U-shape, comprising a
bight 18 and a palr of legs 20.
l'he wire 10 has a pulp-contacting face 22 and an
opposite face 24, against which the foils are adapted to scrape.
The patch 1~ is positioned over the pulp-contacting face 22.
When the patch is assembled by the staples 16, as shown in
Figures 6 and 7, the bight 18 o~ each staple engages the opposlte
face 24 and the legs extend through the wire 10 and the patch
14, and the legs 20 are outwardly bent and curved with their
outer ends dlgging into the fabric of the patch 14, as clearly
shown in E`igure 7, Slnce the bight 18 compresses the thickness
of the wire 10, it does not protrude from the remaining opposite
face 24 and, therefore, the bights 18 will not be affected by the
folls of the paper-making machine.
Preferably, the staples 16 are equally, angularly
spaced around the patch, as shown in Flgure 6, and their legs,
which are outwardly bent, are radially directed. With this
arrangement, the patch is firmly held to the wire 10 and the
patch and staples will not cause defects in the paper made with
~ ~ 20~ the~patched wire, as has been tested in several experi~ents made
-~ in Canada.
Obviously, more than one circular row of staples 16 may
be used, wlth all the circles of staples belng generally
concentric with the perforation 12.
Figures l to 5 show a pre4erred apparatus for securlng
the patch to the wire by means of the staples 16, lrhis apparatus
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comprises a circular base plate 26 secured to the underside of a
table 28 by means of bolts 30 and straddling an opening 32, made
in the table 28. The table is used to support the wire 10 with
its perforation 12 over opening 32, the wire being placed on the
table with its pulp-contacting face 22 on top.
A plurality of plungers 34 are secured to the base
plate 26 and upwardly extend therefrom, A pusher plate 36 is
disposed over the base plate 26 and has a plurality of through-
bores 38, each slidably receiving a plunger 34. The pusher plate
36 is guided for up-and-down movement by means of guide bolts 40
screwed within the pusher plate 36 and slidably extending through
a through-bore made in the base plate 26, with the head 42 of the
bolt underneath the latter, The head 42 of the gulde bolts
serves as a stop means to limit the upward movement of the pusher
: plate to:an advanced position, slightly below the top face of the
table 28.
Compression coil springs 44 surround each bolt 40, abut
against the underside of the pusher plate 36 and against the
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shoulder formed:by a countersunk portion of the through-bore for
~the~guide bolts 40, as shown at 46, Thus, the pusher plate 36
~:;: can take a ret:racted position, as shown in Figure 4, against the
bias~of the coil springs 44, and in which the pusher plate abuts
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against the base plate 26.
The apparat~us further includes a soft pad 48, of a size
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su~Eicient to extend beyond the patch 14. This pad 48 ls made of
soft~material, preferabl~y elastomeric material, such as rub~er,
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for easy insertion of the legs 20 of the staples 16, without
bending of the same
In the advanced position of the pusher plate, one
inserts a staple in each through-bore 38 of the pusher plate 36,
with the bight 18 contacting the end of the plunger 34 and,
therefore, with the legs 20 of each staple being upwardly
directed.
The stroke of the pusher plate from its retracted to
its advanced position is at least equal to the length of each
staple 16. Therefore, in the advanced position of the pusher
plate, each staple inserted in its throu~h-bore 38 does not
protrude from the wire-contacting face 50 of the pusher plate 36,
and yet in the retracted position of the pusher plate, the end of
the plunger is at least flush with the wire-contacting~face 50,
as shown in Figure 4
To operate the apparatus, the wire 10 is placed on the
ta~le 28, with the perforation 12 to be patched over the pusher
plate. ~ The patch 14 is placed over the perforation 12. Pad 48
is~ placed over the patch 14 and then:pressed downwardly, as shown
~20 ~in F~igure ~9, whereby the assembly of the wire 10 and patch 19 is
fo~rced against~face 50 of the;pusher:plate 46, and the latter is
pushed down against base~ plate~26 against the bias of the coil~
sprLngs 44, whereby all of the staples 16 are pushed up through
the~wlre 10 and pa~tch:~l4, and thelr legs 20 enter the pad 98.
The~assembly~is then shlfted over a recessed portion 52 of table
~28 pro~ided~ with a clrcular ~ridge 54. The circular row of
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staples 16 is placed in register with ridge 54. A pair of
handtools 56, each terminated by a flat blade 58, are used, after
removal of pad 48, to press against bight 18 and to individually
bend each leg 20 of each s~aple 16 radially outwardly against the
patch lq.
Although the through-bores 38 are shown as of rounded
cross^sectional shApe, it is preferred to make them of elonga~ed
cross-sectional shape, together with the plungers 34, such a
shape conforming to the cross-sectional shape of a staple 16, so
as to automatically orient the staples, so that their legs 28
would be, without any difficulty, bent radially outwardly along
: radial lines of the patch 14.
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