A pick-up roll apparatus is disclosed for picking up a tail of a web from a forming wire and for transferring the tail to a press felt wrapping around a portion of the apparatus. The apparatus includes a perforate rotatable shell which is disposed adjacent to the forming wire, the shell having a first and a second end. A stationary core is disposed within the shell, the core defining a tail box which is bounded by the shell. The tail box is disposed adjacent to one of the ends of the shell and is selectively connected to a source of partial vacuum such that when the tail of the web is cut on the forming wire, the tail is drawn from the forming wire onto the press felt which wraps around the rotatable shell. The core also defines a downstream chamber which extends between the first end and the second end of the shell. The chamber is bounded by the shell and is connected to the source of vacuum such that during widening of the tail to a full-width sheet, a flow of air through the press felt and through the perforate shell towards the downstream chamber urges the widened tail towards the press felt. The tail box and the downstream chamber are in fluid communication with each other so that any tendency of the tail to detach from the press felt in the vicinity of the tail box during the widening of the tail is inhibited.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a pick-up roll apparatus for picking up a 
tail of a web from a forming wire. More particularly, the present 
invention relates to a pick-up roll apparatus which transfers the tail to 
a press felt which wraps around a portion of the pick-up roll apparatus. 
2. Information Disclosure Statement 
In the papermaking art, a web is formed on a fourdrinier wire by ejecting 
stock onto the wire and draining water from the stock through the wire. 
Subsequently, the partially dewatered web is transferred from the 
fourdrinier forming wire onto a press felt where the web is conveyed 
between counter-rotating press rolls, or the like, for further dewatering 
the web. 
Typically, the transfer from the forming wire to a press felt is 
accomplished by means of a pick-up roll, which is disposed closely 
adjacent to the forming wire. The press felt wraps around a portion of the 
pick-up roll such that the formed web is disposed between the fourdrinier 
wire and the press felt. 
In many pick-up rolls, a central core of the pick-up roll defines a 
full-width chamber having an open face towards that portion of the pick-up 
roll wrapped by the press felt. The chamber which extends in a 
cross-machine direction is connected to a source of partial vacuum, and 
the core rotatably supports a perforate roll shell such that as the press 
felt extends around and wraps the pick-up roll shell, the roll shell 
rotates relative to the pick-up chamber. When the pick-up chamber is 
connected to the source of partial vacuum, the full-width sheet is pulled 
towards the press felt so that a transfer of the full-width sheet to the 
press felt is effected. 
More recently, pick-up rolls have been proposed which include not only a 
pick-up chamber, but also a tail box or end box disposed adjacent to one 
edge of the web. The tail box, which is usually approximately six inches 
in width, is connected to a source of partial vacuum so that during a 
transfer operation, a tail cutter disposed upstream relative to the 
pick-up roll cuts a six inch wide tail from the formed web. 
When the tail has been cut, both the tail and the remainder of the 
full-width sheet are discharged to a broke pit disposed beneath the 
fourdrinier wire. 
The vacuum source is then connected to the tail box so that the tail is 
drawn towards the press felt by the vacuum in the tail box, and the tail 
is guided by the press felt through the press section. 
Once the tail has been stabilized through the press section, the tail 
cutter is moved in a cross-machine direction across the forming wire such 
that the tail is widened to a full-width sheet. 
In view of the movement of the formed web and the cross-machine directional 
movement of the tail cutter, the tail is widened and assumes a diagonal 
leading edge until the tail cutter completes movement across the web. 
However, such prior tail threading operations have always been accomplished 
by turning off the vacuum supply to the tail box and by then turning on 
the vacuum supply to the cross-machine directional vacuum chamber during 
the tail widening operation. 
Consequently, a problem has existed in that when the vacuum to the tail box 
is turned off, there exists a tendency for that edge of the web adjacent 
to the tail box to drop off of the press felt while the remainder of the 
tail, which is being widened to a full-width sheet, is being supported by 
the cross-machine directional vacuum chamber. 
The present invention overcome the aforementioned problem by the provision 
of a downstream chamber which is connected to the same source of vacuum as 
the tail box so that during the tail widening step, a relatively low 
vacuum is applied along the entire cross-machine directional width of the 
widened tail, including that portion of the tail moving over the tail box. 
When the tail has been widened to a full-width sheet, a relatively high 
vacuum is applied through an upstream vacuum chamber defined by the core 
for maintaining the transfer of the full-width sheet to the press felt. 
Therefore, the present invention overcomes the aforementioned inadequacies 
of the prior art arrangements and provides a pick-up roll apparatus which 
makes a considerable contribution to the art of transferring a tail of a 
web from a forming section to a press section. 
Another object of the present invention is the provision of a pick-up roll 
apparatus which includes a downstream vacuum chamber which is connected to 
a tail box for controlling the transfer of a tail from a forming wire onto 
a press felt while the tail is being widened to a full-width sheet. 
Other objects and advantages of the present invention will be readily 
apparent to those skilled in the art by a consideration of the detailed 
description contained hereinafter, taken in conjunction with the annexed 
drawings. 
SUMMARY OF THE INVENTION 
A pick-up roll apparatus and method is disclosed for picking up a tail of a 
web from a forming wire and for transferring the tail to a press felt 
wrapped around a portion of the apparatus. 
The pick-up roll apparatus includes a perforate rotatable shell which is 
disposed adjacent to the forming wire, the shell having a first and a 
second end. 
A stationary core is disposed within the shell, the core defines a tail box 
which is bounded by the shell. The tail box is disposed adjacent to one of 
the ends of the shell with the tail box being selectively connected to a 
source of partial vacuum such that when the tail of the web is cut on the 
forming wire, the tail is drawn from the forming wire onto the press felt, 
which wraps around the rotatable shell. 
The core also defines a downstream chamber which extends between the first 
and the second end of the shell. The chamber is bounded by the shell and 
is connected to the source of vacuum such that during widening of the tail 
to a full-width sheet, a flow of air through the press felt and through 
the perforate shell towards the downstream chamber urges the widened tail 
towards the press felt. The tail box and the downstream chamber are in 
fluid communication with each other so that any tendency for the tail to 
detach from the press felt in the vicinity of the tail box during the 
widening of the tail is inhibited. 
In a more specific embodiment of the present invention, the rotatable shell 
defines an inner and an outer surface. The shell also defines a plurality 
of holes with each hole extending from the inner to the outer surface, the 
holes being located over the entire outer surface of the shell. 
The stationary core also includes a first and a second journal which are 
disposed respectively in the vicinity of the first and the second end of 
the rotatable shell for rotatably supporting the shell such that the shell 
is permitted to rotate relative to the core. 
The tail box is sector-shaped and has an open face towards a portion of the 
shell which is wrapped by the press felt. The arrangement is such that 
during a tail threading operation, when the tail has been cut, vacuum is 
applied to the tail box for generating a current of air which flows 
towards the tail box for drawing the tail from the forming wire onto the 
press felt as the press felts wraps the perforate shell. 
The downstream chamber is disposed adjacent to a portion of the rotatable 
shell, which is wrapped by the press felt and is disposed immediately 
upstream from where the press felt diverges from the shell following the 
wrapped portion. 
The core also includes an upstream chamber which extends between the first 
and the second end of the shell. The upstream chamber is disposed upstream 
relative to the downstream chamber and is connected to a further source of 
partial vacuum. The arrangement is such that when the tail has been 
widened to a full-width sheet, the upstream chamber is connected to the 
further source of vacuum for urging the full-width sheet away from the 
forming wire and towards the press felt so that the full-width sheet is 
transferred from the forming onto the press felt. 
The further source of partial vacuum is at a higher vacuum level than the 
source of vacuum applied to the tail box and the downstream chamber. 
Many modifications and variations of the present invention will be readily 
apparent to 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 within the spirit and scope 
of the present invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 is a perspective view of a pick-up roll apparatus, generally 
designated 10 according to the present invention, for picking up a tail T 
of a web W from a forming wire 12 and for transferring the tail T to a 
press felt 14 which wraps around a portion 16 of the apparatus 10. 
The apparatus 10 includes a rotatable shell 18 which is disposed adjacent 
to the forming wire 12. The shell 18 has a first and a second end 20 and 
22, respectively. 
A stationary core 24 is disposed within the shell 18. The core 24 defines a 
tail box 26 which is bounded by the shell 18. The tail box 26 is disposed 
adjacent to the end 20 of the shell 18. The tail box 26 is selectively 
connected to a source of partial vacuum 28 such that when the tail T of 
the web W is cut on the forming wire 12 by a tail cutter, generally 
designated 30, the tail T is drawn from the forming wire 12 onto the press 
felt 14, which wraps around the rotatable shell 18. 
FIG. 2 is a diagrammatic representation viewed from beneath the vacuum roll 
apparatus 10 showing the tail box 26 which cooperates with the tail T of 
the web W. As shown in FIG. 2, the core 24 also defines a downstream 
chamber 27 which extends between the first and second ends 20 and 22 of 
the shell 18. The chamber 27 is bounded by the shell 18 and is connected 
to the source of partial vacuum 28. The arrangement is such that during 
widening of the tail T to a full-width sheet, as indicated by the arrow 
FWS, a flow of air, as indicated by the arrow 34, through the press felt 
14 and through the perforate shell 18 towards the downstream chamber 27 
urges the widened tail WT towards the press felt 14. The tail box 26 and 
the downstream chamber 27 are in fluid communication with each other so 
that any tendency for the tail T to detach from the pres felt 14 in the 
vicinity of the tail box 26 during the widening of the tail T is 
inhibited. 
FIG. 3 is a top plan view of the apparatus 10 and shows the tail cutter 30 
moving in a cross-machine direction CD, thereby producing a diagonal 
leading edge 36 on the widened tail WT. 
FIG. 4 is a sectional view taken on the line 4-4 of FIG. 3. FIG. 4 shows 
the rotatable shell 18 defining an inner and an outer surface 38 and 40, 
respectively. The shell 18 also defines a plurality of holes 41,42 and 43 
with each hole extending from the inner surface 38 to the outer surface 
40. The holes 41 to 43 are located over the entire outer surface of the 
shell 18. 
FIG. 2 shows the stationary core 24 as further including a first and second 
journal 44 and 46, respectively, which are disposed respectively in the 
vicinity of the first and second end 20 and 22 of the rotatable shell 18 
for rotatably supporting the shell 18 such that the shell 18 is permitted 
to rotate relative to the core 24. 
FIG. 4 shows the tail box 26 having a sector-like shape and having an open 
face 48 facing towards a portion 16 of the shell 18 wrapped by the press 
felt 14. The arrangement is such that during a tail threading operation, 
when the tail T has been cut, vacuum is applied to the tail box 26 for 
generating a current of air, as indicated by the arrow 34, so that the 
current of air flows towards the tail box 26 for drawing the tail T from 
the forming wire 12 onto the press felt 14 as the press felt 14 wraps the 
perforate shell 18. 
FIG. 5 is a sectional view taken on the line 5--5 of FIG. 3 and shows the 
downstream chamber 27 disposed adjacent to the portion 16 of the rotatable 
shell 18 wrapped by the press felt 14. The downstream chamber 27 is 
disposed immediately upstream from where the press felt 14 diverges from 
the shell 18 following the wrapped portion 16. 
As shown in FIG. 5, the core 24 also defines an upstream chamber 50. The 
upstream chamber 50 extends between the first and second ends 20 and 22, 
respectively, of the shell 18. The upstream chamber 50 is disposed 
upstream relative to the downstream chamber 27. The upstream chamber 50 is 
connected to a further source of partial vacuum 52. The downstream chamber 
27 and upstream chamber 50 are each sector-shaped. As can be seen in FIGS. 
2, 4 and 5, the cross section of the sector defined by the tail box 26 is 
substantially equal to the total cross section of the sectors defined by 
both the downstream chamber 27 and the upstream chamber 50. The 
arrangement is such that when the tail T has been widened to a full-width 
sheet FWS, the upstream chamber 50 is connected to the further source of 
vacuum 52 for urging the full-width sheet FWS away from the forming wire 
12 and towards the press felt 14 so that the full-width sheet FWS is 
transferred from the forming wire 12 onto the press felt 14. 
The further source of partial vacuum 52 is at a higher vacuum level than 
the source of vacuum 28 applied to the tail box 26 and the downstream 
chamber 27. 
The present invention provides a vacuum pick-up roll which overcomes the 
problem of edge detachment during a tail widening operation.