Note: Claims are shown in the official language in which they were submitted.
- 8 -
The embodiments of the invention in which an
exclusive property or privilege is claimed are defined
as follows:
1. A papermaking machine comprising:
a breast roll, a forming board and a forming
wire passing around the breast roll and over the
forming board;
a headbox for producing a jet of paper
stock, the headbox including a lower slice lip having
an apron, the lower slice lip and apron projecting
beyond of the center of the breast roll in the
direction of wire travel; and,
the forming board including a lead-in blade
section and a rear section, the rear section being
spaced rearwardly of the apron in the direction of
paper stock travel to provide a gap between the apron
and rear section, the rear section being positioned
substantially in alignment with the apron and the
lead-in blade section being angled with respect to the
rear section to project downwardly below the
substantial alignment of the rear section and the
apron, the forming wire passing over the lead-in blade
section and changing direction of travel, as the wire
passes through the gap and over the rear section, to a
direction of travel in alignment with the rear section
such that the jet of paper stock leaving the headbox
passes across the gap and is laid onto the forming
wire at the rear section of the forming board at
substantially zero degrees angle of impingement to
thereby minimize disturbance of the paper stock and
minimize drainage as the stock leaves the headbox and
impinges the wire.
2. The papermaking machine of claim 1
wherein the lead-in blade section slopes downwardly
from the rear section at an angle between 5 to 15
degrees.
- 9 -
3. The papermaking machine of claim 2
wherein the angle is between 10 and 15 degrees.
4. The papermaking machine of claim 1
wherein the lead-in blade section slopes downwardly
from the rear section at an angle of about 15 degrees.
5. The papermaking machine of claim 1
wherein the gap between the apron and the rear section
of the forming board is about 3 inches.
6. The papermaking machine of claim 1
wherein the breast roll is positioned beneath a plane
defined by the rear section of the forming board.
7. The papermaking machine of claim 1
wherein the lead-in blade section includes and edge
portion and a front wall extending below the forming
wire rearwardly and downwardly away from the edge
whereby the front wall enhances the amount of fluid
deflected by the lead-in blade section through the
forming wire and along the front wall.
8. The papermaking machine of claim 7
wherein the front wall is spaced adjacent the breast
roll and has a curvature that follows the peripheral
surface of the breast roll.
9. A papermaking machine comprising:
a breast roll, a forming board and a forming
wire passing around the breast roll and over the
forming board at a predetermined velocity;
a headbox for producing a jet of paper
stock, the headbox including a lower slice lip having
an apron, the lower slice lip and apron projecting
beyond of the center of the breast roll in the
direction of wire travel; and,
the forming board including a lead-in blade
section and a rear section, the rear section being
spaced rearwardly of the apron in the direction of
paper stock travel to provide a gap between the apron
- 10 -
and rear section, the rear section being positioned
substantially in alignment with the apron and the
lead-in blade section being angled with respect to the
rear section to project downwardly below the
substantial alignment of the rear section and the
apron, the forming wire passing over the lead-in blade
section and changing direction of travel, as the wire
passes through the gap and over the rear section, to a
direction of travel in alignment with the rear section
such that the jet of paper stock leaving the headbox
passes travels across the gap at said predetermined
velocity and laid onto the forming wire at the rear
section of the forming board at substantially zero
acceleration relative to the velocity of the
travelling wire to thereby minimize disturbance of the
paper stock and minimize drainage as the stock leaves
the headbox and impinges the wire.
10. The papermaking machine of claim 9
wherein the lead-in blade section slopes downwardly
from the rear section at an angle between 5 to 15
degrees.
11. The papermaking machine of claim 10
wherein the angle is between 10 and 15 degrees.
12. The papermaking machine of claim 9
wherein the lead-in blade section slopes downwardly
from the rear section at an angle of about 15 degrees.
13. The papermaking machine of claim 9
wherein the gap between the apron and the rear section
of the forming board is about 3 inches.
14. The papermaking machine of claim 9
wherein the breast roll is positioned beneath a plane
defined by the rear section of the forming board.
15. The papermaking machine of claim 9
wherein the lead-in blade section includes and edge
portion and a front wall extending below the forming
- 11 -
wire rearwardly and downwardly away from the edge
whereby the front wall enhances the amount of fluid
deflected by the lead-in blade section through the
forming wire and along the front wall.
16. The papermaking machine of claim 15
wherein the front wall is spaced adjacent the breast
roll and has a curvature that follows the peripheral
surface of the breast roll.
17. A papermaking machine comprising:
a forming wire;
a headbox for producing a jet of paper
stock, the headbox including a lower slice lip having
an apron; and,
a forming board having a rear section, a
lead-in blade and a front wall, the rear section being
positioned beside the apron and spaced rearwardly of
the apron in the direction of paper stock travel to
provide a gap between the apron and rear section;
the lead-in blade being positioned beneath
the lower slice lip with the lower slice lip
overlapping the lead-in blade, and the lead-in blade
projecting forwardly and downwardly from the rear
section in the direction of wire travel to define a
passage between the lower slice and the lead-in blade
where the lower slice overlaps the lead-in blade, the
forming wire passing over the lead-in blade, along the
passage, through the gap and over the rear section of
the forming board to receive the jet of paper stock,
the front wall extending below the forming wire
rearwardly and downwardly away from the lead-in blade,
the lead in blade deflecting fluid, pumped by the
forming wire, away from the passage and the gap
through the forming wire and along the front wall
prior to the forming wire reaching the passage so as
to reduce the amount of fluid pumped by the wire along
- 12 -
the passage through the gap toward the underside of
the jet of paper stock and thereby reducing the
disturbing effect on the underside of the stock caused
by fluid passage along the passage through the gap.
18. The papermaking machine of claim 17
further including an exhaust located rearwardly of the
lead-in blade in the direction of wire travel, said
exhaust being positioned adjacent the passage and the
gap to draw away any remaining fluid left in the
forming wire prior to the forming wire passing through
the gap and reaching the underside of the jet of paper
stock.
19. The papermaking machine of claim 17
further including an exhaust located in the front wall
below the lead-in blade and the forming wire to
enhance the amount of fluid deflected by the lead-in
blade through the forming wire and along the front
wall.
20. The papermaking machine of claim 17
further including a breast roll around which the
forming wire travels, the breast roll being positioned
below the headbox, the lead-in blade and the front
wall.
21. The papermaking machine of claim 18
wherein the apron has an undersurface having a tip
projecting downwardly into the passage toward the
forming wire in advance of the gap in the direction of
wire travel.
22. The papermaking machine of claim 21
wherein the tip contacts the forming wire.
23. A papermaking machine comprising:
a forming wire;
a headbox for producing a jet of paper
stock, the headbox including a lower slice lip having
an apron; and,
- 13 -
a forming board having a rear section, a
lead-in blade and a front wall;
the rear section being spaced rearwardly of
the apron in the direction of paper stock travel to
provide a gap between the apron and rear section, the
forming wire passing through the gap and over the rear
section of the forming board to receive the jet of
paper stock; and
the lead-in blade being spaced rearwardly of
the apron and projecting forwardly and downwardly from
the rear section in the direction of wire travel and,
the front wall extending below the forming wire
rearwardly and downwardly away from the lead-in blade,
the lead-in blade deflecting fluid, pumped by the
forming wire, away from the gap through the forming
wire and along the front wall prior to the forming
wire reaching the gap, an exhaust being located in the
front wall below the lead-in blade and the forming
wire to enhance the amount of fluid deflected by the
lead-in blade through the forming wire and along the
front wall and to reduce the amount of fluid pumped by
the forming wire through the gap toward the underside
of the jet of paper stock and thereby reducing the
disturbing effect on the underside of the jet caused
by fluid passing through the gap.
24. The papermaking machine of claim 23
wherein the apron has an undersurface having a tip
projecting downwardly toward the forming wire in
advance of the gap in the direction of wire travel.
25. The papermaking machine of claim 24
wherein the tip contacts the forming wire.
26. The papermaking machine of claim 17
wherein the front wall is spaced adjacent the breast
roll and has a curvature that follows the peripheral
surface of the breast roll.
- 14 -
27. The papermaking machine of claim 23
wherein the front wall is spaced adjacent the breast
roll and has a curvature that follows the peripheral
surface of the breast roll.
28. A papermaking machine comprising:
a breast roll, a forming board and a forming
wire passing around the breast roll and over the
forming board;
a headbox for producing a jet of paper
stock, the headbox including a lower slice lip having
an apron, the lower slice lip and apron projecting
beyond of the center of the breast roll in the
direction of wire travel; and,
the forming board having a rear section, a
lead-in blade and a front wall;
the rear section being spaced rearwardly of
the apron in the direction of paper travel to define a
gap therewith through which the forming wire passes as
the wire travels over the forming board to receive the
jet of paper stock; and,
the lead-in blade being positioned above the
front wall forwardly and downwardly from the rear
section, the front wall extending rearwardly and
downwardly from the lead-in blade, the lead-in blade
deflecting fluid pumped by the forming wire through
the forming wire and along the front wall reducing the
amount of fluid pumped toward the underside of the jet
of paper stock and thereby reducing the disturbing
effect this fluid has on the underside of the jet.