U.S. patent application number 14/714590 was filed with the patent office on 2016-11-24 for bladder system for curing composite parts.
The applicant listed for this patent is The Boeing Company. Invention is credited to Amy Elizabeth Bahe, Megan E. Bliss, William Hollensteiner, William Henry Ingram, JR., John Dempsey Morris, Jonathan Santiago, Benjamin Jeffrey Stephenson, Samuel Ray Stewart, Charles William Thomas.
Application Number | 20160339682 14/714590 |
Document ID | / |
Family ID | 57325081 |
Filed Date | 2016-11-24 |
United States Patent
Application |
20160339682 |
Kind Code |
A1 |
Bahe; Amy Elizabeth ; et
al. |
November 24, 2016 |
Bladder System for Curing Composite Parts
Abstract
A structure comprising a plurality of walls defining a bladder
cavity, the bladder cavity comprises an initial cross section size.
A first plurality of wave features provided along at least one of
the plurality of walls defining the bladder cavity. In one
arrangement, the first plurality of wave features allow the
structure to expand from the initial cross section size to a second
cross section size after the structure becomes inflated during a
composite charge cure, the second cross section size larger than
the initial cross sectional size.
Inventors: |
Bahe; Amy Elizabeth;
(Seattle, WA) ; Bliss; Megan E.; (SeaTac, WA)
; Hollensteiner; William; (Auburn, WA) ; Ingram,
JR.; William Henry; (Puyallup, WA) ; Morris; John
Dempsey; (Seattle, WA) ; Santiago; Jonathan;
(Seattle, WA) ; Stephenson; Benjamin Jeffrey;
(Seattle, WA) ; Stewart; Samuel Ray; (Redmond,
WA) ; Thomas; Charles William; (Issaquah,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Boeing Company |
Chicago |
IL |
US |
|
|
Family ID: |
57325081 |
Appl. No.: |
14/714590 |
Filed: |
May 18, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 33/505 20130101;
B29C 70/342 20130101 |
International
Class: |
B32B 37/10 20060101
B32B037/10 |
Claims
1. A structure comprising: a plurality of walls defining a bladder
cavity, the bladder cavity comprises an initial cross section size,
and a first plurality of wave features provided along at least one
of the plurality of walls defining the bladder cavity.
2. The structure of claim 1, the first plurality of wave features
allow the structure to expand from the initial cross section size
to a second cross section size after the structure becomes inflated
during a composite charge cure, the second cross section size
larger than the initial cross sectional size.
3. The structure of claim 1 wherein the plurality of walls of the
structure comprise: a bottom wall; a first side wall extending from
the bottom wall; a second side wall extending from the bottom wall;
a first end wall; a second end wall; and a top wall extending from
the first end wall to the second end wall enclosing the structure,
the bottom wall, the first side wall, the second side wall, the
first end wall, the second end wall, and the top wall defining the
bladder cavity, and wherein at least one of the bottom wall, the
top wall, the first side wall, the first end wall, the second end
wall, or the second side wall comprises the first plurality of wave
features.
4. The structure of claim 2, wherein the first plurality of wave
features extend over a length of the at least one of the bottom
wall, the top wall, the first side wall, the first end wall, the
second end wall, or the second side wall.
5. The structure of claim 3, wherein the first plurality of wave
features extend over a portion of a length of the at least one of
the bottom wall, the top wall, the first side wall, the first end
wall, the second end wall, or the second side wall.
6. The structure of claim 1, wherein the first plurality of wave
features comprise a plurality of uniform wave features.
7. The bladder of claim 6, wherein the plurality of uniform wave
features each comprise an equivalent radius of curvature.
8. The structure of claim 3, wherein at least one of the bottom
wall, the top wall, the first side wall, the first end wall, the
second end wall, or the second side wall comprises a second
plurality of wave features.
9. The structure of claim 8, wherein the first plurality of wave
features comprise a first radius of curvature and the second
plurality of wave features comprise a second radius of curvature,
wherein the first radius of curvature is different than the second
radius of curvature.
10. The structure of claim 1 further comprising a pressure fitting
that is adapted to be coupled with a vacuum source used to inflate
the bladder cavity from the initial cross section size to the
second cross section size.
11. A method of curing a charge, the method comprising the steps of
placing a charge on a tool; positioning a structure having an
initial cross section size in a charge cavity of the charge placed
on the tool; laying up plies over the structure positioned in the
charge cavity; coupling the structure to a vent port; sealing a
vacuum bag over the charge, the layed up plies, the tool, and the
structure; drawing a vacuum; initiating a debulking process of the
charge by inflating the structure; beginning to expand the
structure from the initial cross section size to a second cross
section size, larger than the initial cross section size; creating
a plurality of micro-buckles within the structure; increasing an
effective pressure that is applied to an inside radii of the
charge; finalizing debulk; and curing the charge.
12. A multilayered bladder system for use in curing of a composite
charge defining an internal cavity, the bladder comprising: a
bladder outer layer, the bladder outer layer defining a top wall, a
bottom wall, a first sidewall, and a second side wall, wherein the
first sidewall and the second sidewall extend between the top wall
and the bottom, a bladder first inner layer, the bladder first
inner layer defining a top wall, a bottom wall, a first sidewall,
and a second side wall, wherein the first side wall and the second
side wall extend between the top wall and the bottom wall, and a
bladder intermediate layer disposed between the bladder outer layer
and the bladder first inner layer.
13. The multilayered bladder system of claim 12 wherein the bladder
outer layer comprises an overlapping top wall.
14. The multilayered bladder system of claim 13 wherein the
overlapping top wall comprises a partially overlapping top
wall.
15. The multilayered bladder system of claim 12 wherein the bladder
first inner layer comprises an overlapping top wall.
16. The multilayered bladder system of claim 15 wherein the
overlapping top wall of the bladder first inner layer comprises a
partially overlapping top wall.
17. The multilayered bladder system of claim 15 further comprising
a layer of fiberglass provided within the overlapping top wall of
the bladder first inner layer.
18. The multilayered bladder system of claim 12 further comprising
a bladder second inner layer, the bladder second inner layer
provided below the top wall of the bladder first inner layer.
19. The multilayered bladder system of claim 18 wherein the bladder
first inner layer comprises an overlapping top wall, and the
bladder second inner layer is provided below the overlapping top
wall of the first inner layer.
20. The multilayered bladder system of claim 18 wherein the bladder
second inner layer comprises a flouroelastic rubber layer.
21. The multilayered bladder system of claim 12 further comprising
a plurality of flouroelastic rubber layers provided between the top
wall of the bladder first inner layer and the intermediate
layer.
22. The multilayered bladder system of claim 12 further comprising
a bladder second inner layer provided between the bladder first
inner layer and the intermediate layer, the bladder second inner
layer extending along at least a portion of the first sidewall of
the first inner layer.
23. The multilayered bladder system of claim 22 wherein the bladder
second inner layer provided between the bladder first inner layer
and the intermediate layer extends along a portion of the second
side wall of the bladder first inner layer.
24. The multilayered bladder system of claim 22 wherein the bladder
second inner layer comprises flouroelastic rubber.
25. The multilayered bladder system of claim 12 wherein the top
wall of the bladder outer layer comprises a first thickness and the
first side wall and the second side wall of the bladder outer layer
comprises a second thickness, wherein the first thickness of the
top wall of the bladder outer layer is different than the second
thickness of the first and second side walls of the bladder outer
layer.
26. A method of curing a charge, the method comprising the steps of
placing a charge on a tool; positioning a multilayered structure in
a charge cavity defined by the charge placed on the tool; laying up
plies over the structure positioned in the charge cavity; coupling
the multilayered structure to a vent port; covering the charge, the
tool, the plies, and the multilayered structure with a vacuum bag
over; drawing a vacuum; initiating a debulking process of the
charge by inflating the multilayered structure; finalizing debulk;
and curing the charge.
27. A bladder system for use in curing a composite charge having an
internal cavity, the bladder system comprising: a bladder
comprising: a bladder bottom wall; a first bladder side wall
extending from the bottom wall; a second bladder side wall
extending from the bottom wall; and a bladder top wall enclosing
the bladder, the bladder bottom wall, the first bladder side wall,
the second bladder side wall, and the bladder top wall defining a
bladder cavity, and a flexible bladder support positioned within
the bladder cavity, such that a first bearing surface of the
flexible bladder support and a second bearing surface of the
flexible bladder support provide a compressive load support between
a bottom surface of the bladder top wall and a top surface of the
bladder bottom wall.
28. The bladder system of claim 27, wherein the flexible bladder
support positioned within the bladder cavity, further provides the
compressive load support between an inner surface of the bladder
first side wall and an inner surface of the bladder second side
wall.
29. The bladder system of claim 27, wherein the flexible bladder
support comprises at least one corkscrew support.
30. The bladder system of claim 27, wherein the flexible bladder
support comprises a sinusoidal support.
31. The bladder system of claim 30 wherein the sinusoidal support
comprises a constant width along a length of the sinusoidal
support.
32. The bladder system of claim 30 further comprising: an
additional support provided between the bladder top wall and the
sinusoidal support.
33. The bladder system of claim 32 wherein: the additional support
provided between the bladder top wall and the sinusoidal support
comprises a rectangular support.
34. The bladder system of claim 30 wherein the sinusoidal support
comprises a non-constant width.
35. The bladder system of claim 27 wherein the flexible bladder
support comprises a segmented support.
36. The bladder system of claim 27 wherein the flexible bladder
support comprises a double concave support.
37. The bladder system of claim 36 wherein the double concave
support comprises: a top bearing surface, a bottom bearing surface,
a first side support, and a second side support, wherein the first
side support extends in a concave manner from a first end of the
bottom bearing surface to a first end of the top bearing surface,
and the second side support extends in a concave manner between a
second end of the bottom bearing surface upwards towards a second
end of the top bearing surface.
38. The bladder system of claim 27, wherein the flexible bladder
support extends along an entire length of the bladder.
39. The bladder system of claim 27, wherein the bladder system
comprises a plurality of wave features.
40. The bladder system of claim 27, wherein the bladder system
comprises a multilayered bladder system.
41. The bladder system of claim 27, wherein the bladder system
comprises a multi-segmented bladder system.
42. A bladder system for use in curing a composite charge
comprising an internal cavity, the bladder system comprising: a
bladder comprising: a bladder bottom wall; a first bladder side
wall extending from the bottom wall; a second bladder side wall
extending from the bottom wall; and a bladder top wall extending
from a bladder front wall to a bladder back wall enclosing the
bladder, the bladder bottom wall, the first bladder side wall, the
second bladder side wall, the bladder top wall, the bladder front
wall, and the bladder back wall defining a bladder cavity, and a
flexible bladder support positioned within the bladder cavity, such
that a first bearing surface of the flexible bladder support and a
second bearing surface of the flexible bladder support provide a
compressive load support between a bottom surface of the bladder
top wall and an inner surface of the bladder first side wall and an
inner surface of the bladder second side wall.
43. The bladder system of claim 42 wherein the flexible bladder
support comprises a trapezoidal bladder support.
44. The bladder support of claim 42 wherein the bladder support
comprises a segmented flexible bladder support.
45. The bladder support of claim 42 wherein the bladder support
comprises a double concave support structure.
46. The bladder support of claim 45, wherein the double concave
support structure comprises: a top bearing surface, a bottom
bearing surface, a first side support, and a second side support,
wherein the first side support extends in a concave manner from a
first end of the bottom bearing surface to a first end of the top
bearing surface, and the second side support extends in a concave
manner between a second end of the bottom bearing surface upwards
towards a second end of the top bearing surface.
47. The bladder support of claim 45 wherein the bladder support
comprises a segmented bladder support.
48. The bladder support of claim 42 wherein the bladder support
comprises a multi-segmented bladder support.
49. A method of curing a charge, the method comprising the steps of
placing a charge on a tool; positioning a bladder in a charge
cavity defined by the charge placed on the tool; positioning a
bladder support into a bladder cavity defined by the bladder;
laying up a plurality of plies over the structure and the bladder
support; providing a compressive load support by the bladder
support; coupling the bladder to a vent port; covering the charge,
the tool, the bladder support, and the bladder with a vacuum bag
over; drawing a vacuum; initiating a debulking process of the
charge by inflating the bladder; finalizing debulk; and curing the
charge.
Description
FIELD
[0001] The present disclosure generally relates to methods and
equipment for fabricating composite resin parts, and generally
relates to bladder systems that are used in curing composite
parts.
BACKGROUND
[0002] Composite resin parts may be cured within an autoclave that
applies heat and pressure to the composite part during a cure
cycle. Some part geometries include internal cavities that may
cause the composite part to collapse under autoclave pressure
unless a tool such as an inflatable bladder is placed in a
composite part cavity. Such an inflatable bladder may be inflated
during a cure process so as to react to the autoclave pressure
force applied to the composite part. Typically, these inflatable
bladders are pressurized by venting them through a vacuum bag.
[0003] There are several problems with the vented bladders that
often lead to inconsistencies in the cured parts. For example,
failure to properly vent the bladder may prevent the bladder from
becoming pressurized sufficiently to react to the applied autoclave
pressures. Similarly, insufficient bladder pressurization may
result from a failure of a sealant used to seal a vent hole
coupling the bladder with an outside vent. It is also possible for
a bladder wall to fail or be penetrated, in which event autoclave
gases may be forced into the part throughout the cure cycle. In
addition, it is sometimes difficult to design a nominal bladder
cross section that is both small enough to fit inside a composite
stringer prior to cure, yet large enough to expand to a desired
cross section during cure. Moreover, because the bladders are
flexible during lay up operations, it can be a manufacturing
challenge for an Automated Fiber Placement machine operation
particularly when orientation dictates that the ply must be laid in
a perpendicular direction to that of the bladder: a situation that
can cause excess fiber length to be laid.
[0004] Accordingly, there is a need for a bladder system that may
reduce or eliminate the adverse effects resulting from leaks in the
bladder or failure to properly pressurize the bladder. There is
also a need for a bladder system that has a desired cross section
that allows the bladder to expand during a cure process. There is
also a need for a bladder system that reduces the cause of excess
fiber length being laid.
SUMMARY
[0005] In one arrangement, a structure comprising a plurality of
walls defining a bladder cavity is disclosed. The bladder cavity
comprises an initial cross section size. A first plurality of wave
features provided along at least one of the plurality of walls
defining the bladder cavity. In one arrangement, the first
plurality of wave features allow the structure to expand from the
initial cross section size to a second cross section size after the
structure becomes inflated during a composite charge cure, the
second cross section size larger than the initial cross sectional
size.
[0006] In one arrangement, the structure comprises a bottom wall, a
first side wall extending from the bottom wall, a second side wall
extending from the bottom wall, a first end wall, a second end
wall, and a top wall extending from the first end wall to the
second end wall enclosing the structure, such that the bottom wall,
the first side wall, the second side wall, the first end wall, the
second end wall, and the top wall define the bladder cavity,
wherein at least one of the bottom wall, the top wall, the first
side wall, the first end wall, the second end wall, or the second
side wall comprises the first plurality of wave features. In one
arrangement, the first plurality of wave features extend over a
length of the at least one of the bottom wall, the top wall, the
first side wall, the first end wall, the second end wall, or the
second side wall.
[0007] In one arrangement, the first plurality of wave features
extend over a portion of a length of the at least one of the bottom
wall, the top wall, the first side wall, the first end wall, the
second end wall, or the second side wall. In one arrangement, the
first plurality of wave features comprise a plurality of uniform
wave features. The first plurality of uniform wave features may
comprise a similar radius of curvature. In one arrangement, at
least one of the bottom wall, the top wall, the first side wall,
the first end wall, the second end wall, or the second side wall
comprises a second plurality of wave features. In such an
arrangement, the first plurality of wave features may comprise a
first radius of curvature and the second plurality of wave features
comprise a second radius of curvature. The first radius of
curvature may be different than the second radius of curvature.
[0008] In one arrangement, a pressure fitting is adapted to be
coupled with a vacuum source for inflating the structure.
[0009] In one arrangement, a method of curing a charge is
described. The method comprising the steps of placing a charge on a
tool; installing a structure having an initial cross section size
in a charge cavity of the charge placed on the tool; coupling the
structure to a vent port; sealing a flex bag over the charge, the
tool, and the structure; drawing a vacuum; debulking the charge by
inflating the structure; beginning to expand the structure from the
initial cross section size to a desired cross section size;
increasing an effective pressure that is applied to an inside radii
of the charge; finalizing debulking; and curing charge.
[0010] In one arrangement, a multilayered bladder system for use in
curing of a composite charge having an internal cavity is
disclosed. The multilayered bladder comprises a bladder outer
layer. The bladder outer layer defining a top wall, a bottom wall,
a first sidewall, and a second sidewall, wherein the first and
second sides walls extend between the top wall and the bottom. The
multilayered bladder further comprising a bladder first inner
layer. The bladder first inner layer defining a top wall, a bottom
wall, a first sidewall, and a second sidewall, wherein the first
and second sides walls extend between the top wall and the bottom
wall. The multilayered bladder further comprising a bladder
intermediate layer disposed between the bladder outer layer and the
bladder first inner layer. In one arrangement, the outer layer
comprises an overlapping top wall. For example, in one arrangement,
the overlapping top wall of the outer layer comprises a partially
overlapping top wall.
[0011] In yet another alternative arrangement, the first inner
layer comprises an overlapping top wall. For example, the
overlapping top wall of the first inner layer comprises a partially
overlapping top wall.
[0012] In one arrangement, the multilayered bladder comprises a
layer of fiberglass provided within the overlapping top wall of the
first inner layer. The multilayered bladder may further comprise a
second inner layer, the second inner layer provided below the top
wall of the first inner layer. For example, in one arrangement, the
first inner layer comprises an overlapping top wall, and the second
inner layer is provided below the overlapping top wall of the first
inner layer. In one arrangement, the second inner layer comprises a
fluoroelastic rubber layer.
[0013] In yet another arrangement, the multilayered bladder further
comprises a plurality of fluoroelastic rubber layers provided
between the top wall of the first inner layer and the intermediate
layer.
[0014] In yet another arrangement, the multilayered bladder further
comprises a second inner layer provided between the first inner
layer and the intermediate layer. The second inner layer extends
along at least a portion of the first sidewall of the first inner
layer. In one arrangement, the second inner layer comprises
fluoroelastic rubber.
[0015] In yet another arrangement, the top wall of the outer layer
comprises a first thickness and the first sidewall and the second
side wall of the outer layer comprises a second thickness. In one
arrangement, the first thickness of the top wall of the outer layer
is different than the second thickness of the first and second
sidewalls of the outer layer.
[0016] In one arrangement, a method of curing a charge is
disclosed. The method comprising the steps of placing a charge on a
tool; positioning a multilayered structure in a charge cavity
defined by the charge placed on the tool; coupling the multilayered
structure to a vent port; covering the charge, the tool, and the
multilayered structure with a flex bag over; drawing a vacuum;
initiating a debulking process of the charge by inflating the
multilayered structure; finalizing debulk; and curing the
charge.
[0017] In one arrangement, a bladder system for use in curing a
composite charge having an internal cavity is disclosed. The
bladder system comprising a bladder comprising a bladder bottom
wall, a first bladder side wall extending from the bottom wall, a
second bladder side wall extending from the bottom wall, and a
bladder top wall extending from a bladder front wall to a bladder
back wall enclosing the bladder. The bladder bottom wall, the first
bladder side wall, the second bladder side wall, the bladder top
wall, the bladder front wall, and the bladder back wall define a
bladder cavity. A flexible bladder support is positioned within the
bladder cavity, such that a first bearing surface of the flexible
bladder support and a second bearing surface of the flexible
bladder support provide a compressive load support between a bottom
surface of the bladder top wall and a top surface of the bladder
bottom wall. In one arrangement, the bladder support further
provides the compressive load support between an inner surface of
the bladder first side wall and an inner surface of the bladder
second side wall. In one arrangement, the flexible bladder support
comprises at least one corkscrew support.
[0018] In another arrangement, the flexible bladder support
comprises a sinusoidal support. In one arrangement, the sinusoidal
support comprises a constant width along a length of the sinusoidal
support. In one arrangement, an additional support is provided
between the bladder top wall and the sinusoidal support. In one
arrangement, the additional support provided between the bladder
top wall and the sinusoidal support comprises a rectangular
support.
[0019] In one arrangement, the support structure comprises a
segmented support.
[0020] In one arrangement, the flexible bladder support comprises a
double concave support. For example, in one arrangement, the double
concave support comprises a top bearing surface, a bottom bearing
surface, a first side support, and a second side support. The first
side support extends in a concave manner from a first end of the
bottom bearing surface to a first end of the top bearing surface.
The second side support extends in a concave manner between a
second end of the bottom bearing surface upwards towards a second
end of the top bearing surface.
[0021] In one bladder system arrangement, the flexible bladder
support extends along an entire length of the bladder. In yet
another bladder system arrangement, the bladder system comprises a
bladder system comprising wave features. In yet another bladder
system arrangement, the bladder system comprises a multilayered
bladder system.
[0022] In yet another arrangement, a bladder system for use in
curing a composite charge having an internal cavity is disclosed.
The bladder system comprising a bladder comprising a bladder bottom
wall, a first bladder side wall extending from the bottom wall, a
second bladder side wall extending from the bottom wall, and a
bladder top wall extends from a bladder front wall to a bladder
back wall enclosing the bladder. The bladder bottom wall, the first
bladder side wall, the second bladder side wall, and the bladder
top wall define a bladder cavity. A flexible bladder support is
positioned within the bladder cavity, such that a first bearing
surface of the flexible bladder support and a second bearing
surface of the flexible bladder support provide a compressive load
support between a bottom surface of the bladder top wall and an
inner surface of the bladder first side wall and an inner surface
of the bladder second side wall. In one arrangement, the flexible
bladder support comprises a trapezoidal bladder support. In one
arrangement, the bladder support comprises a segmented flexible
bladder support.
[0023] In an alternative arrangement, the bladder support comprises
a double concave support structure. In one arrangement, the double
concave support structure comprises a top bearing surface, a bottom
bearing surface, a first side support, and a second side support.
The first side support extends in a concave manner from a first end
of the bottom bearing surface to a first end of the top bearing
surface. The second side support extends in a concave manner
between a second end of the bottom bearing surface upwards towards
a second end of the top bearing surface. In one arrangement, the
bladder support comprises a segmented bladder support.
[0024] In an alternative arrangement, a method of curing a charge
is disclosed. The method comprising the steps of placing a charge
on a tool; positioning a bladder in a charge cavity defined by the
charge placed on the tool; positioning a bladder support into a
bladder cavity defined by the bladder; laying up a plurality of
plies over the structure and the bladder support; providing a
compressive load support by the bladder support; coupling the
bladder to a vent port; covering the charge, the tool, and the
bladder with a flex bag over; drawing a vacuum; initiating a
debulking process of the charge by inflating the bladder;
finalizing debulk; and curing the charge.
[0025] The features, functions, and advantages can be achieved
independently in various arrangements of the present disclosure or
may be combined in yet other arrangements in which further details
can be seen with reference to the following description and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The novel features believed characteristic of the
illustrative arrangements are set forth in the appended claims. The
illustrative arrangements, however, as well as a preferred mode of
use, further objectives and descriptions thereof, will best be
understood by reference to the following detailed description of an
illustrative arrangement of the present disclosure when read in
conjunction with the accompanying drawings, wherein:
[0027] FIG. 1 is an illustration of a functional block diagram of a
bladder system according to disclosed arrangements;
[0028] FIG. 2 is an illustration of a perspective view of a
composite resin stringer cured using the bladder system shown in
FIG. 1;
[0029] FIG. 3 is an illustration of an alternative bladder
arrangement that may be used with the bladder system illustrated in
FIG. 1;
[0030] FIG. 4 is a vertical section through the bladder system 100,
taken along line 4-4 in FIG. 3;
[0031] FIG. 5 illustrates a detailed view of the portion designated
as "A" in FIG. 3;
[0032] FIG. 6 illustrates steps of a method for autoclave curing
using the alternative bladder arrangement illustrated in FIG.
3;
[0033] FIG. 7 illustrates a perspective view of a charge that has
been placed in a cavity of a tool, such as the tool illustrated in
FIG. 1;
[0034] FIG. 8 illustrates a detailed view of the portion designated
as "B" in FIG. 7;
[0035] FIG. 9 illustrates a perspective view of a bladder that has
been placed in a cavity of a tool, such as the bladder illustrated
in FIG. 3;
[0036] FIG. 10 illustrates a detailed view of the portion
designated as "C" in FIG. 9;
[0037] FIG. 11 is an illustration of an alternative bladder
arrangement that may be used with the bladder system illustrated in
FIG. 1;
[0038] FIG. 12 is an illustration of an alternative bladder
arrangement that may be used with the bladder system illustrated in
FIG. 1;
[0039] FIG. 13A is an illustration of an alternative bladder
arrangement that may be used with the bladder system illustrated in
FIG. 1;
[0040] FIG. 13B illustrates steps of a method for autoclave curing
using the alternative bladder arrangement illustrated in FIG.
3;
[0041] FIG. 14A is an illustration of an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0042] FIG. 14B is a cross sectional view of the bladder support
illustrated in FIG. 14A;
[0043] FIG. 15A is an illustration of an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0044] FIG. 15B is a cross sectional view of the bladder support
illustrated in FIG. 15A;
[0045] FIG. 16A is an illustration of an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0046] FIG. 16B is a cross sectional view of the bladder support
illustrated in FIG. 16A;
[0047] FIG. 17A an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0048] FIG. 17B is a cross sectional view of the bladder support
illustrated in FIG. 17A;
[0049] FIG. 18A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0050] FIG. 18B is a cross sectional view of the bladder support
illustrated in FIG. 18A;
[0051] FIG. 19A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0052] FIG. 19B is a cross sectional view of the bladder support
illustrated in FIG. 19A;
[0053] FIG. 20A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0054] FIG. 20B is a cross sectional view of the bladder support
illustrated in FIG. 20A;
[0055] FIG. 21A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0056] FIG. 21B is a cross sectional view of the bladder support
illustrated in FIG. 21A;
[0057] FIG. 22A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0058] FIG. 22B is a cross sectional view of the bladder support
illustrated in FIG. 22A;
[0059] FIG. 23A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0060] FIG. 23B is a cross sectional view of the bladder support
illustrated in FIG. 23A;
[0061] FIG. 24A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0062] FIG. 24B is a cross sectional view of the bladder support
illustrated in FIG. 24A;
[0063] FIG. 25A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0064] FIG. 25B is a cross sectional view of the bladder support
illustrated in FIG. 25A;
[0065] FIG. 26A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0066] FIG. 26B is a cross sectional view of the bladder support
illustrated in FIG. 26A;
[0067] FIG. 27A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0068] FIG. 27B is a cross sectional view of the bladder support
illustrated in FIG. 27A;
[0069] FIG. 28A is an illustration an exemplary bladder support
positioned within a bladder, such as the bladder illustrated in
FIGS. 6 and 7;
[0070] FIG. 28B is a cross sectional view of the bladder support
illustrated in FIG. 28A;
[0071] FIG. 29A is an illustration an exemplary bladder
support;
[0072] FIG. 29B is a cross sectional view of the bladder support
illustrated in FIG. 28A, positioned within a bladder, such as the
bladder illustrated in FIGS. 6 and 7;
[0073] FIG. 30A is an illustration an exemplary bladder
support;
[0074] FIG. 30B is a cross sectional view of the bladder support
illustrated in FIG. 30A, positioned within a bladder, such as the
bladder illustrated in FIGS. 6 and 7;
[0075] FIG. 31A is an illustration an exemplary bladder
support;
[0076] FIG. 31B is an illustration the exemplary bladder support
illustrated in FIG. 31A positioned within a bladder, such as the
bladder illustrated in FIGS. 6 and 7;
[0077] FIG. 31C is a cross sectional view of the bladder support
system illustrated in FIG. 31B;
[0078] FIG. 32A is an illustration an exemplary bladder
support;
[0079] FIG. 32B is an illustration an exemplary bladder
support;
[0080] FIG. 32C is an illustration an exemplary bladder
support;
[0081] FIG. 32D is an illustration an exemplary bladder
support;
[0082] FIG. 33 illustrates steps of a method for autoclave curing
using a bladder support, such as the bladder supports arrangements
illustrated in FIGS. 14-32;
[0083] FIG. 34 is an illustration of a perspective view of an
aircraft that may incorporate one or more composite laminate
structures manufactured in accordance with one or more arrangements
disclosed herein;
[0084] FIG. 35 is an illustration of a flow diagram of aircraft
production and service methodology; and
[0085] FIG. 36 is an illustration of a block diagram of an
aircraft.
DETAILED DESCRIPTION
[0086] Disclosed arrangements will now be described more fully
hereinafter with reference to the accompanying drawings, in which
some, but not all of the disclosed arrangements are shown. Indeed,
several different arrangements may be provided and should not be
construed as limited to the arrangements set forth herein. Rather,
these arrangements are provided so that this disclosure will be
thorough and complete and will fully convey the scope of the
disclosure to those skilled in the art.
[0087] Referring first to FIG. 1, an uncured composite resin part
10, may be hereafter referred to as a "charge", a "composite
charge", a "composite part charge" or a "stringer charge." Such a
charge may be supported within the autoclave. Specifically, the
charge 10 may be cured on a cure tool 15 placed in an autoclave 35
in which autoclave heat 34 and pressure 36 are applied to the
composite charge 10. The composite charge 10 includes one or more
internal voids, trapped or enclosed areas, or cavities, which for
ease of description, will collectively be referred hereinafter as a
charge cavity 45.
[0088] A bladder system 60 comprising a flexible, inflatable
bladder 55 is also provided. As just one example, and as will be
described in greater detail herein with respect to FIGS. 3-10, the
inflatable bladder 55 may comprise a plurality of wave features. In
yet another alternative bladder system 60 arrangement, and as will
be described in greater detail with respect to FIGS. 11-13, the
bladder system 60 may comprise a multilayered bladder.
Alternatively, and as also will be described in greater detail
herein with respect to FIGS. 14-30, the bladder system 60 may
comprise a bladder support positioned within a bladder cavity 56
defined by the flexible, inflatable bladder 55.
[0089] The flexible, inflatable bladder 55 may be placed within or
may be inserted into the internal cavity 45 of the cure tool 15
prior to a cure cycle in order to react external pressures applied
to the charge 10 during a curing process, such as during an
autoclave curing process. As will be described in greater detail
herein, a bladder support structure 58 may be positioned in the
bladder cavity 56 defined by the bladder 55. Plies 12 are laid up
over the bladder and cure tool 15. Such a process step may take
place by an Automated Fiber Placement machine. These laid up plies
will eventually form stringer flanges.
[0090] A flexible bag, such as a vacuum bag 25, may be placed and
sealed over the flexible bladder 55, the cure tool 15, and the
plies and then secured to the cure tool 15. As such, the vacuum bag
25 would provide vacuum covering to the composite charge 10, the
laid up plies 12, and the inflatable bladder 55. The flexible bag
25 is adapted to be coupled with a suitable vacuum source 30 for
evacuating the flexible bag 25.
[0091] Referring now to FIG. 2, the disclosed bladder systems and
curing methods may be employed to cure a variety of composite resin
parts of various geometries, having one or more internal cavities.
For example, and without limitation, the various disclosed bladder
systems and methods may be used in the fabrication of a fiber
reinforced composite resin stringer 20. In one preferred
arrangement, this stringer 20 may comprise a multi-ply layup of
prepreg. Other stringer materials may also be used, such as without
limitation dry fiber reinforcing or tackified dry fiber
reinforcing. In this illustrated arrangement, the stringer 20
comprises a hat section 40 forming an internal stringer cavity 22,
a pair of laterally extending flange sections 50 A,B, and a
substantially flat skin section 52 that is consolidated together
with the flange sections 50 A,B during curing. A plurality of plies
21 making up the stringer are illustrated in FIG. 2. As those of
ordinary skill in the art will recognize, alternative stringer
compositions and geometries are possible.
[0092] FIG. 3 illustrates a perspective view of one implementation
of a preferred bladder system 100 that may be used in the system
illustrated in FIG. 1. FIG. 4 is a vertical section through the
bladder system 100, taken along line 4-4 in FIG. 3. A pressure
fitting 106 is provided in the front wall 104 of the bladder
arrangement 100. Referring now to FIGS. 3 and 4, the bladder system
100 comprises a bladder 105 comprising a bladder bottom wall 110
that is generally sized to be placed along a bottom, internal
surface of a charge cavity, such as the cavity 45 of charge 10
illustrated in FIG. 1. The bladder 105 further comprises a first
bladder side wall 120 that extends up from the bottom wall 110 and
also comprises a second bladder side wall 125 that also extends
from the bottom wall 110. A top wall 130 extends from a bladder
front wall 104 to a bladder back wall 101 and encloses the bladder
105 so that the bladder bottom wall 110, the first bladder side
wall 120, the second bladder side wall 125, the bladder front wall
104, the bladder back wall 101, and the bladder top wall 130 define
an internal bladder cavity 135. The first bladder side wall 120 and
the bladder top wall 130 define a first upper corner 123 and the
second bladder side wall 125 and the bladder top wall 130 define a
second upper corner 124. Similarly, The first bladder side wall 120
and the bladder bottom wall 110 define a first lower corner 128 and
the second bladder side wall 125 and the bladder bottom wall 110
define a second lower corner 129.
[0093] As illustrated in FIG. 3, the bladder system 100 may also
comprise a pressure fitting 106 that is adapted to be coupled to a
source of pressurized fluid (such as the fluid source 32
illustrated in FIG. 1) such as air for inflating the bladder system
100, and with a vacuum source for deflating the bladder (source as
the vacuum source 30 illustrated in FIG. 1). In this illustrated
arrangement, the bladder 105 comprises an elongate structure that
extends over a bladder length L.sub.B 115. In one arrangement, the
bladder length L.sub.B 115 is generally equivalent to the length of
a cure tool. However, in an alternative arrangement, the bladder
length L.sub.B 115 may be longer than the cavity of the charge,
extending out the ends of the charge. As those of skill in the art
will recognize, alternative bladder length L.sub.B 115
configurations may also be used. In addition, the bladder 105
further comprises a generally trapezoidal cross section 117
although other geometrical configurations and structures may be
used as well.
[0094] As illustrated, this bladder system 100 comprises a
structure 101 and this structure comprises a plurality of wave
features 140 in the form of curving or undulating features.
Specifically, in this bladder arrangement 100, a first plurality of
wave features 140 is provided along the bladder top wall 130. In
one preferred arrangement, the first plurality of wave features 140
extend along the entire length L.sub.B 115 of the bladder 105.
Similarly, a second plurality of wave features 142 are provided
along a length of the first bladder side wall 120 and a third
plurality of wave features 144 are also provided along a length of
the second bladder side wall 125. As illustrated, the second
plurality of wave features 142 run parallel to one another along
the length of the first bladder side wall 120. The third plurality
of wave features 144 run parallel to one another along the length
of the second bladder side wall 125.
[0095] In an alternative exemplary bladder system, the first
plurality of wave features 140 may be provided along only along a
portion of the length L.sub.B 115 of the bladder top wall 130. As
illustrated, the first plurality of wave features 140 run parallel
to one another along the length 115 of the bladder top wall 130.
Similarly, a second plurality of wave features 142 may be provided
along only a portion of the length L.sub.B 115 of the first bladder
side wall 120 and a third plurality of wave features 144 may be
provided only along a portion of the length L.sub.B 115 of the
second bladder side wall 125). In one preferred arrangement, and as
illustrated in FIGS. 3-4, the first plurality of wave features 140,
the second plurality of wave features 142, and the third plurality
of wave features 144 are all similar to one another. That is, each
of the plurality of wave features 140, 142, 144 comprise a similar
geometrical configuration or radius of curvature.
[0096] Although the bladder system 100 as illustrated comprises
similar wave features 140, 142, 144, those of ordinary skill in the
art will recognize that alternative curving or undulating features
may also be utilized. As just one example, in certain bladder
system arrangements, only the bladder top wall 130 may comprise
wave features 140, 142, 144 while the remaining bladder walls (the
first and second side walls 120, 125 the bottom wall 110) do not
comprises wave features 140, 142, 144. Alternatively, perhaps only
a portion of the bladder top wall 130 may comprise wave features
140, 142, 144. Similarly, in yet another alternative bladder system
arrangement, wave features 140, 142, 144 may only be provided along
one or both of bladder side walls 120, 125. In addition, although
the bladder bottom wall of the bladder 100 as illustrated in FIGS.
3 and 4 does not comprise wave features, in an alternative bladder
arrangements, similar or different wave features 146 may be
provided along this bladder bottom wall 110 as well.
[0097] FIG. 5 illustrates a detailed view 126 of the portion 128
designated as "A" of the bladder system 100 illustrated in FIGS. 3
and 4. Specifically, FIG. 5 illustrates a close up view 126 of the
second upper corner 124 of a bladder system 100 defined by an upper
portion 126 of the bladder second side wall 125 and a right hand
portion 131 of the bladder top wall 130 of the bladder 105
illustrated in FIGS. 3 and 4. As in this close up view illustrated
in FIG. 5, the plurality of wave features 142 provided along the
top wall 130 and the plurality of wave features 144 provided along
second side walls 120 comprise similar wave features. That is, each
of the first and second plurality of wave features 142, 144
comprise a similar geometrical configuration such as a radius of
curvature 121. As just one example, the wave features 142, 144 all
comprise similar wave features having a radius of curvature 121
equal to approximately 0.5000 inches. Similarly, the plurality of
wave features provided along the top wall 130 comprise wave
features having a similar radius of curvature 121 equal to
approximately 0.5000 inches. However, as those of ordinary skill in
the art will recognize, alternative bladder configurations with
alternative or different geometrical configurations and/or radius
of curvatures may be utilized.
[0098] As just one example, in one bladder arrangement, a first
plurality of wave features may be provided along the first sidewall
120. This first plurality of wave features 140 may have a first
radius of curvature 121. In this same bladder arrangement, a second
plurality of wave features 142 may be provided along the top wall
130 and this second plurality of wave features 142 may comprise a
second radius of curvature 121 that is different from the first
radius of curvature 121 of the first plurality of wave features
140. Similarly, a third plurality of wave features 144 may be
provided along the second sidewall 125. The third plurality of wave
features 144 may be of similar or different dimensions then either
the first and second plurality of wave features 140, 142.
[0099] Attention is now directed to FIG. 6 which broadly
illustrates steps of a method 150 for autoclave curing using the
bladder system 100 described above with reference to FIGS. 3-5. For
example, and beginning at step 152, a composite resin charge is
supported within an autoclave by being placed on a suitable tool,
such as the cure tool 15 discussed with reference to FIG. 1. At
step 154, forming aids (not shown) may be used to press the various
plies making up the charge down into the mold cavity, and conform
the charge to radii 178 A, B in the tool cavity 173. The varies
plies 191 making up the charge 190 define a charge cavity 192.
[0100] At step 156, a bladder 180 comprising a plurality of wave
features 181 is positioned into the charge cavity 192 and over the
charge 190. For example, FIG. 7 illustrates a bladder 180
comprising a plurality of wave features 181 positioned within the
charge cavity 192 and over a charge 190. As illustrated, the charge
190 comprising a plurality of plies 191 that has been placed within
a tool cavity 173 of a tool 175 and also after the plies 191 of the
charge 190 has conformed to the radii 178A, 178B of the tool cavity
176. In addition, FIG. 8 illustrates a detailed view of the portion
designated as "B" in FIG. 7 and illustrating the plies 191 of the
charge 190 conforming to the tool radii 178A,B. As illustrated in
FIG. 8, a second lower corner 198 of the bladder 180 provides
slight compaction to the laid up plies 191 residing along the tool
radii 178B.
[0101] Prior to cure, the bladder 180 includes wave features 181 as
previously discussed. Initially, the bladder 180 comprises an
initial cross sectional size W.sub.ICSS 184 as first installed into
the tool cavity 173.
[0102] Returning to the method illustrated in FIG. 6, at step 158
plies 194 are laid up over the bladder 180 and the tool 175. Such a
process step may take place by an Automated Fiber Placement
machine. As may be seen from FIG. 7, these laid up plies 194 will
eventually help form the stringer flanges 196 A,B, such as the
stringer flanges 50 A,B illustrated in FIG. 2.
[0103] Then, at step 160, the bladder 180 may be coupled to a vent
port. Such a vent port allows the bladder 180 to be inflated to a
desired pressure and also allows the bladder to inflate to a
desired cross section size 186. One exemplary venting port 176 is
illustrated in FIG. 7. Returning to the method 150 illustrated in
FIG. 6, at step 162, the composite charge 190, the laid up plies
194, along with the bladder 180 are covered with a flexible bag
such as the vacuum bag 25 illustrated in FIG. 1. The vacuum bag 25
may then be sealed to the cure tool 175. At step 164, a vacuum
within the vacuum bag 25 is drawn.
[0104] At step 166, the debulk process is initiated. During this
step, autoclave pressure P.sub.A is applied to the vacuum bag 25 in
order to initiate compression of the various plies 191 making up
the charge 190. In addition, autoclave pressure P.sub.A is also
initially applied to an interior or cavity of the bladder 180 by
way of the venting port, pressurizing the bladder 180 so as to
react to forces applied to the composite charge 190 by autoclave
pressure. At step 168, the bladder 180 begins to expand from its
initial cross section size 184 to a desired cross section size
186.
[0105] At step 170, the interior of the bladder 180 is internally
pressurized with autoclave pressure P.sub.A. This internal
pressurization of the bladder 180 causes a force P.sub.A to be
applied to the composite charge 190. Therefore, the composite
charge 190 being molded can be cured in the autoclave while the
bladder 180 maintains its inflated state at this desired cross
section size 186. An increased bladder cross section size 186 helps
to ensure, that during the curing and molding process, an outer
surface 198 of the composite charge 190 is forced against a
respective tool surface 176 of the tool 175. This also increases
the effective pressure applied to an inside radii 186 of the charge
190.
[0106] For example, FIG. 9 illustrates a perspective view of the
bladder 180 illustrated in FIG. 7 after the bladder 180 has been
inflated so as to achieve a desired cross section size W.sub.DCSS
186 during the cure cycle. As illustrated in FIG. 9, the desired
cross section size W.sub.DCSS 186 of the inflated bladder is
greater than the initial cross section size W.sub.ICSS 184 of the
bladder 184 prior to inflation (FIG. 7). As also illustrated in
FIG. 9, the desired cross section size 186 of the inflated bladder
180 has compressed the composite plies 191 making up the charge
190. Specifically, the desired cross section size 186 of the
inflated bladder 180 has caused the second lower corner 129 of the
bladder 180 to compress the composite plies 191 making up the
charge 190 into the tool radii 178B.
[0107] Returning to FIG. 6, at step 172, debulking of the charge
190 continues under the application of heat. Debulking continues by
compacting or squeezing out air and volatiles between plies 191 or
prepreg laminates of the charge 190 under moderate heat and vacuum
so as to insure seating on the tool 175, to prevent wrinkles, and
to promote adhesion. Next, at step 174, the plurality of wave
features 181 create a plurality of "micro-buckles" that will tend
to increase an amount of compression of the various bladder walls
against the composite plies 191. At step 176, when curing is
complete, the autoclave pressure P.sub.A is removed from the vacuum
bag 25, and therefore is also removed from the interior of the
bladder 180.
[0108] The bladder 105, 180 illustrated and described with
reference to FIGS. 3-10 provides a number of advantages. For
example, because of the way the stringers are processed as
discussed herein, the inner cross section 184 of the laid up
composite plies 190 making up the charge cavity 192 is smaller (so
the charge cavity 192 is narrower) prior to cure than it is after
cure. Cf FIGS. 7 and 9. This is due in part to the "debulking"
process that occurs during compaction and cure of the composite
plies 191, 194. This debulking process is accounted for by both the
coefficient of thermal expansion (CTE) of the bladder material
(which is typically much higher than the CTE of the surrounding
structure and the CTE of the mold the hat is built in) and by the
inherently elastic nature of the bladder material (typically,
rubber), especially when pressurized by an autoclave cure cycle.
Unfortunately, it is sometimes difficult to design a nominal
bladder cross section that is both small enough to fit inside the
stringer prior to cure, and large enough to expand to the desired
cross section during cure.
[0109] If the bladder 105, 180 is too small for the final cross
section, the bladder 180 will bridge across the radii 186 of the
charge 190 during cure. Radii bridging can result if the bladder
does not have continuous compressive contact with the radius from
the start of the radius section to the end of the radius section.
Bridging can result in structurally unacceptable wrinkles and resin
richness and radius thickening If, on the other hand, the bladder
105, 180 is designed too large to properly fit into the precure
cross section of the stringer, the bladder walls may buckle during
initial bladder placement and when drawing of vacuum. Sometimes, if
the buckling is minor, the buckle will flatten out during the
debulk process and cure. Unfortunately, many times the buckle will
not flatten out, and the final composite part will include
inconsistent and unpredictable resin ridges and ply
distortions.
[0110] The disclosed bladder systems as discussed in detail with
respect to FIGS. 3-10 tend to reduce such buckling issues. For
example, and as shown in FIGS. 7-10, the wave features 140,142,144
of the bladder system 100 will tend to effectively increase a total
peripheral length of the bladder system 100 without increasing an
initial cross sectional size 184 of the bladder system 100.
Therefore, the bladder system 100 will have a cross section 184
that will allow the bladder system 100 to fit into the cure tool
prior to cure. Such a bladder cross section 184 will therefore be
allowed to expand to a somewhat larger cross section during the
debulking process. For example, as illustrated in FIGS. 8-10, as
the plurality of wave features 181 allow the bladder 180 to expand
to achieve the desired cross section W.sub.DCS 186, the bladder 180
pushes plies 191 into the tool radii 178A,B while preventing the
bladder 180 from bridging at the tool radii 178A,B.
[0111] Another advantage of the presently disclosed bladder systems
is that such bladder systems will effectively create a plurality of
"micro-buckles" during the cure process. This will tend to increase
an amount of compression of the bladder walls prior to them forming
a single large buckle (which would not go away during cure).
Finally, due to the compression that will be created in the bladder
walls during the debulk cycle (where the buckles are effectively
flattening under autoclave pressure), there will be an increase in
the effective pressure applied to an inside radii of the
stringer.
[0112] FIG. 11 illustrates an alternative multilayered bladder
system 200. As illustrated, the bladder system 200 comprises a
multilayered bladder system. Such a multilayered bladder system
comprises a bladder outer layer 204. This outer layer 204 is
configured so as to define an outer layer top wall 204a, an outer
layer bottom wall 204b, an outer layer first sidewall 204c, and an
outer layer second sidewall 204d. As illustrated, the outer layer
first and second sides walls 204c,d extend between the outer layer
top wall 204a and the outer layer bottom wall 204b. In this
illustrated multilayered bladder system 200, the bladder outer
layer 204 comprises an overlapping top wall 206. That is, a portion
of the bladder outer layer 204 overlaps with itself along the top
wall of the bladder system 200. In this illustrated arrangement,
the overlapping top wall extends across an entire width W.sub.TWOL
210 of the top wall outer layer 204.
[0113] In an alternative multilayered bladder arrangement, only a
portion of the outer layer 204 overlaps with itself along the top
wall of the bladder system 200. As just one example, the outer
layer 204 may overlap with itself over only a portion of the
overall width W.sub.TWOL 210 of the outer bladder top wall 204a,
such as only about a 25% overlap.
[0114] The multilayered bladder system 200 further comprises a
bladder inner layer 218. This bladder inner layer 218 is configured
so as to define an inner layer top wall 218a, an inner layer bottom
wall 218b, an inner layer first sidewall 218c, and an inner layer
second sidewall 218d. As illustrated, the inner layer first
sidewall 218c and inner layer second sidewall 218d extend between
the inner layer top wall 218a and the outer layer bottom wall 218b.
In this illustrated multilayered bladder system 200, the inner
layer 218 comprises an overlapping top wall 222. That is, a portion
of the inner layer 218 overlaps with itself along the top wall of
the bladder system 200. In this illustrated arrangement, the
overlapping top wall extends across an entire width W.sub.TWIL 222
of the top wall inner layer 218.
[0115] In an alternative multilayered bladder arrangement, only a
portion of the inner layer 218 overlaps with itself along the top
wall of the bladder system 200. As just one example, the inner
layer 218 may overlap with itself over only a portion of the width
W.sub.TWIL 222 of the inner layer top wall 218a, such as only about
a 25% overlap.
[0116] The bladder system 200 further comprises an intermediate
layer 240. This intermediate layer 240 is disposed between the
outer layer 204 and the inner layer 218. Preferably, this
intermediate layer 240 is disposed along the bottom, top, and first
and second side walls. In one example, the intermediate layer 240
comprises a Nylon layer. Alternatively, the intermediate layer 212
comprises a fiberglass layer. Additionally, the intermediate layer
212 may also comprise a reinforcement which may comprise a
substantially rigid material, such as, for example and without
limitation, a woven fiberglass. The intermediate layer 240 serves a
number of functions. For example, the intermediate layer 240 can
provide the bladder system 200 with enhanced structural rigidity.
In addition, the intermediate layer 240 of the bladder system 200
can also reduce the tendency of the bladder system 200 to shrink
over repeated uses.
[0117] In one alternative bladder system arrangement, at least one
separate inner layer 246 may be further provided along the top wall
of the bladder system 200. As just one example, a separate inner
layer 244 may be provided along a bottom surface of the inner layer
top wall 218a. (i.e., situated along a bottom surface 214 of the
inner layer top wall 218a). As just another example, at least one
separate inner layer 246 is provided between a top surface of the
inner layer top wall 218a and the intermediate layer 240. In yet
another example, a plurality of separate inner layers are provided
between a top surface of the inner layer top wall 218a and the
intermediate layer 240. In either such separate inner layer
arrangements, the separate inner layer may comprise a separate
layer of Viton material, a separate layer of nylon, a separate
layer of fiberglass, and/or a combination of these materials.
[0118] In yet another alternative arrangement, the multilayered
bladder system 200 illustrated in FIG. 11 may comprise a
multilayered bladder system comprising at least a first plurality
of wave features 140. (e.g., such as the wave features 140, 142,
144, and 146 illustrated and discussed herein with respect to FIGS.
3-10) For example, a first plurality of wave features 140 could be
provided on at least a portion of either the bladder outer layer
first side wall 204c, the second bladder sidewall 204d, the bladder
top wall 204a and/or the bladder bottom wall 204b. As those of
ordinary skill in the art will recognize, alternative multilayered
bladder systems may also be utilized.
[0119] In one preferred arrangement, the bladder inner layer 218
comprises a fluoroelastic rubber, such as Viton.RTM.. Similarly, in
one preferred arrangement, the bladder outer layer 204 also
comprises a fluoroelastic rubber, such as Viton.RTM.. As those of
ordinary skill in the art will recognize, fluoroelastomer is a
special purpose fluorocarbon-based synthetic rubber that has wide
chemical resistance and superior performance, particularly in high
temperature applications. The fluoroelastomeric rubber has a
relatively low coefficient of thermal expansion, thus providing the
multilayered bladder system 200 with enhanced dimensional
stability. Preferably, the thickness of the inner and outer layers
of 218, 204 fluoroelastomeric rubber will depend upon the
particular application. As just one example, the thickness of the
inner layer 218 and the outer layer 204 may be approximately 0.060
inches.
[0120] FIG. 12 illustrates another alternative multilayered bladder
system 300 that may be used in the bladder system illustrated in
FIG. 5. As illustrated, the multilayered bladder system 300
comprises a bladder outer layer 304. This outer layer 304 is
configured so as to define an outer layer top wall 304a, an outer
layer bottom wall 304b, an outer layer first sidewall 304c, and an
outer layer second side wall 304d. As illustrated, the outer layer
first and second sides walls 304c,d extend between the outer layer
top wall 304a and the outer layer bottom wall 304b. In this
illustrated bladder system 300, the outer layer top wall 304a
comprises an overlapping top wall 308. That is, a portion of the
outer layer 304 overlaps with itself along the top wall of the
bladder system 300. In this illustrated arrangement, the
overlapping top wall extends only along a portion of the entire
width W.sub.TWOL 310 of the top wall of the outer layer 304.
[0121] Similarly, the bladder system 300 illustrated in FIG. 12
further comprises an inner layer 318. This inner layer 318 is
configured so as to define an inner layer top wall 318a, an inner
layer bottom wall 318b, an inner layer first sidewall 318c, and an
inner layer second side wall 318d. As illustrated, the inner layer
first and second sides walls 318c,d extend between the inner layer
top wall 318a and the outer layer bottom wall 318b. In this
illustrated bladder system 300, the inner layer 318 comprises an
overlapping top wall 322. That is, a portion of the inner layer 318
overlaps with itself along an entire width of the top wall of the
inner layer 318. In this illustrated arrangement, the overlapping
top wall 322 extends across an entire width W.sub.TWIL 326 of the
top wall of the inner layer 318.
[0122] In an alternative arrangement, only a portion of the bladder
inner layer 318 may be overlapped with itself along the top wall
322 of the bladder system 300. As just one example, the inner layer
318 may only be overlapped with itself over a portion of the width
W.sub.TWIL 326 of the inner layer top wall, such as only about 25%
overlap.
[0123] The multilayered bladder system 300 further comprises an
intermediate layer 330. As illustrated in FIG. 12, the intermediate
layer 330 is disposed between the bladder outer layer 304 and the
bladder inner layer 318. In this preferred arrangement, the
intermediate layer 330 extends along the bottom walls, the top
walls, the first side walls and the second side walls of the
bladder system 300. In one exemplary arrangement, the intermediate
layer 330 comprises a Nylon layer. Alternatively, the intermediate
layer 330 comprises a fiberglass layer. The intermediate layer 330
may also comprise a reinforcement which may include a substantially
rigid material, such as, for example and without limitation, a
woven fiberglass. The intermediate layer 330 serves a number of
advantages. For example, the intermediate layer 330 can provide the
bladder system 300 with enhanced structural rigidity. In addition,
the intermediate layer 330 can also reduce the tendency of the
bladder system 300 to lose its original form (i.e., shrink) over
repeated uses.
[0124] In one alternative bladder system arrangement, the bladder
system 300 may further comprise a separate inner layer 340. As just
one example and as may be seen from FIG. 12, this separate inner
layer 340 may be provided along the top wall of the bladder system
300. As just one example, the separate inner layer 340 may be
provided along a top surface of the inner layer top wall 318a and
extend along at least a portion of the inner layer first side wall
318c and at least a portion of the inner layer second side wall
318d. In one preferred arrangement, the separate inner layer 340
comprises a layer of Viton material. Alternatively, the separate
inner layer 340 comprises a fiberglass layer.
[0125] In yet another alternative arrangement, the multilayered
bladder system 300 illustrated in FIG. 12 comprises a multilayered
bladder system comprising at least a first plurality of wave
features. For example, a plurality of wave features may be provided
on at least a portion of either the bladder outer layer first side
wall 304c, the second side wall 304d, the top wall 304a, and/or the
bottom wall 304b.
[0126] FIG. 13A illustrates another alternative multilayered
bladder system 400. As illustrated, the multilayered bladder system
400 comprises a bladder outer layer 402. This bladder outer layer
402 is configured so as to define an outer layer top wall 402a, an
outer layer bottom wall 402b, an outer layer first sidewall 402c,
and an outer layer second side wall 402d. As illustrated, the outer
layer first and second sides walls 402c,d extend between the outer
layer top wall 402a and the outer layer bottom wall 402b. In this
illustrated bladder system 400, the outer layer top wall 402a
comprises an overlapping top wall 404. That is, a portion of the
outer layer 402 overlaps with itself along the top wall of the
bladder system 400. In this illustrated arrangement, the
overlapping top wall 404 extends only along a portion of an entire
width W.sub.TWOL 406 of the top wall of the outer layer 404.
[0127] The bladder system 400 illustrated in FIG. 13A further
comprises a bladder first inner layer 408. This bladder first inner
layer 408 is configured so as to define an inner layer top wall
408a, an inner layer bottom wall 408b, an inner layer first
sidewall 408c, and an inner layer second side wall 408d. As
illustrated, the inner layer first and second sides walls 408c,d
extend between the inner layer top wall 408a and the outer layer
bottom wall 408b. In this illustrated bladder system 400, the inner
layer 408 comprises an overlapping top wall 410. That is, in this
illustrated arrangement, a first portion of the inner layer 408
overlaps a second portion of the inner layer 408 along an entire
width W.sub.TWIL 412 of the top wall of the inner layer 408. In
this illustrated arrangement, the overlapping top wall extends
across an entire width W.sub.TWIL 412 of the top wall of the inner
layer 408.
[0128] The bladder system 400 further comprises a separate or
second inner layer 414. As may be seen from FIG. 13A, this separate
inner layer 414 is provided within the first portion of the bladder
inner layer 408 and the second portion of the overlapping top wall
410 of the inner layer 408. In this illustrated arrangement, the
separate inner layer 414 extends along at least a portion of the
inner layer top surface. In one preferred arrangement, the separate
inner layer 414 may comprise a layer of Viton material.
Alternatively, the separate inner layer 414 comprises a fiberglass
layer.
[0129] The multilayered bladder system 400 further comprises an
intermediate layer 416. As illustrated in FIG. 13A, the
intermediate layer 416 is disposed between the bladder outer layer
402 and the bladder first inner layer 408. In this preferred
arrangement, the intermediate layer 416 extends along the bottom
walls, the top walls, the first side walls and the second side
walls of the bladder system 400. In one exemplary arrangement, the
intermediate layer 416 comprises a Nylon layer. Alternatively, the
intermediate layer 416 comprises a fiberglass layer. The
intermediate layer 416 may also comprise a reinforcement which may
include a substantially rigid material, such as, for example and
without limitation, a woven fiberglass. The intermediate layer 416
serves a number of advantages. For example, the intermediate layer
416 can provide the bladder system 400 with enhanced structural
rigidity. In addition, the intermediate layer 416 can also reduce
the tendency of the bladder system 400 to lose its original form
(i.e., shrink) over repeated uses.
[0130] In yet another alternative arrangement, the multilayered
bladder system 400 illustrated in FIG. 13A comprises a multilayered
bladder system comprising at least one plurality of wave features.
For example, in one exemplary multilayered bladder system, wave
features are provided on at least a portion of either the bladder
outer layer first side wall 404c, the second side wall 404d, the
top wall 404a, and/or the bottom wall 404b.
[0131] The disclosed multilayered bladder systems provide a number
of advantages. For example, a standard fuselage production bladder
has a significant amount of resin richness. Resin richness
describes an uneven distribution or excessive use of resin within
the cured composite laminate. Areas of resin richness typically are
subject to cracking Though this resin richness can be repaired for
production use, the repairs can be costly and may require many
hours of rework. The standard bladder also has encountered handling
issues, leaks, shrinkage, and overall durability issues that limit
the number of cures that can be performed per ship set. The bladder
systems as described herein which comprise multilayers of Viton and
fiberglass layers provide a number of advantages of conventional
type bladder systems. For example, the disclosed multilayered
bladder systems help to reduce leaks, reduce shrinkage, and provide
enhanced overall durability which leads to reducing costly repairs
and wasted man hours.
[0132] Attention is now directed to FIG. 13B which broadly
illustrates steps of a method 420 for autoclave curing using a
multilayered bladder system, such as the systems described above
with reference to FIGS. 11-13A. For example, and beginning at step
422, a composite resin charge is supported within an autoclave by
being placed on a suitable tool, such as the cure tool 15 discussed
with reference to FIG. 1. At step 424, forming aids (not shown) may
be used to press the various plies making up the charge down into
the mold cavity, and conform the charge to radii in the mold
cavity.
[0133] At step 426, a multilayered bladder is inserted into the
tool cavity over the charge. At step 428, additional plies may be
laid over the bladder. At step 430, the bladder is coupled to a
vent port. Such a venting port allows the bladder to be inflated to
a desired pressure and also allows the bladder to inflate to a
desired cross section size. This venting port 176 is illustrated in
FIGS. 7 and 9. At step 432, the composite charge along with the
bladder are covered with a flexible bag such as the vacuum bag 25
illustrated in FIG. 1. The vacuum bag may then be sealed to the
cure tool. At step 434, a vacuum within the vacuum bag is
drawn.
[0134] At step 436, the debulk process is initiated wherein
autoclave pressure P.sub.A is applied to the vacuum bag in order to
initiate compression of the various plies making up the charge. In
addition, autoclave pressure P.sub.A is also initially applied to
an interior or cavity of the bladder by way of the venting port,
pressurizing the bladder so as to react to forces applied to the
composite charge by autoclave pressure. At step 438, the interior
of the bladder is internally pressurized with autoclave pressure
P.sub.A. This internal pressurization of the bladder causes a force
P.sub.A to be applied to the composite charge. Therefore, the
composite charge being molded can be cured in the autoclave while
the bladder maintains its inflated state at this desired cross
section size. An increased bladder cross section size helps to
ensure, that during the curing and molding process, the outer
surface of the composite charge will be forced against respective
tool surfaces of the tool. This also increases the effective
pressure applied to the inside radii of the charge.
[0135] At step 440, debulking of the charge continues under the
application of heat. Debulking continues by compacting or squeezing
out air and volatiles between plies or prepreg laminates of the
charge under moderate heat and vacuum so as to insure seating on
the tool, to prevent wrinkles, and to promote adhesion. At step
442, when curing is complete, the autoclave pressure P.sub.A is
removed from the vacuum bag, and therefore is also removed from the
interior of the bladder.
[0136] As described above, the bladder system 60 illustrated in
FIG. 1 may comprise a bladder having wave features, such as the
exemplary bladder systems discussed and illustrated with respect to
FIGS. 3-10. As also described herein, in an alternative
arrangement, the bladder system 60 illustrated in FIG. 1 comprises
a multilayered bladder system comprising a bladder with inner
layers, outer layers, and intermediate layers of various materials
such as Viton, nylon, and/or fiberglass. In yet another alternative
bladder system arrangement, the bladder system 60 illustrated in
FIG. 1 comprises a bladder system comprising, in combination, an
bladder along with a flexible internal bladder support wherein the
bladder support is provided within a bladder inner cavity defined
by the bladder so as to provide a compressive load support between
a bottom surface of a bladder top wall and a top surface of a
bladder bottom wall.
[0137] Flexible internal bladder supports that provide compressive
load support as disclosed and described herein provide a number of
benefits. For example, flexible bladders are often used in
applications where the bladders need to react a head pressure of
automatic fiber placement machines when prior to the bladder being
pressurized (as they are during autoclave cure). One example might
be a hat-stiffened panel where the panel plies are laid by machine
after the hat-stringers have already been placed in the layup tool.
Because the bladders are flaccid during these operations, it can be
a manufacturing challenge for machine operation particularly when
orientation dictates that the ply must be laid in a perpendicular
direction to that of the bladder which can also cause excess fiber
length to be laid. The presently disclosed internal flexible
bladder support provides the support needed during skin/panel fiber
placement needed while otherwise not affecting the bladders'
performance adversely.
[0138] In addition, the presently disclosed bladder support systems
also tend to prevent excessive tow layup. Additionally, such
bladder support systems also tend to allow the fiber to be layed
more quickly, hence achieving a higher quality laminate. Typical
bladder systems without such an internal bladder support oftentimes
results in a lower quality laminate that requires causes rework or
even a scrapped barrel when composite wrinkles are in excess.
[0139] In addition, the presently disclosed bladder supports are
generally light in weight, so that the radius fillers (i.e.,
noodles) will not fall out of their respective troughs during skin
application. In addition, the bladder support material is strong,
and able to withstand up to 120 pounds of Automatic Fiber Placement
(AFP) head pressure for purposes of enhanced composite quality. The
bladder support material is generally flexible for highly contoured
stringers, and conforms in transition areas (i.e., joggle areas) as
necessary. Moreover, the presently disclosed bladder supports are
decoupled from the bladder and therefore do not interfere with the
bladder's ability to adequately expand in the autoclave during the
cure cycle.
[0140] In one preferred internal bladder arrangement, the bladder
support is configured to provide a compressive load support between
a bottom surface of a bladder top wall and a top surface of a
bladder bottom wall. In an alternative bladder support system
arrangement, the bladder support provides a compressive load
support between a bottom surface of a bladder top wall, a top
surface of a bottom wall of the bladder, an inside surface of a
first bladder sidewall, and an inside surface of a second bladder
sidewall of the flexible bladder. (See, e.g., FIGS. 15A,B, 19A,B,
20A,B, 21A,B, 27A,B, 28A,B, 29A,B, and 30A,B). In yet another
alternative arrangement, the bladder support is configured to
provide a compressive load support between a bottom surface of a
bladder top wall, an inside surface of a first bladder side wall
and an inside surface of a second bladder side wall of a flexible
bladder. (See, e.g., FIGS. 24A,B, 25A,B, and 26A,B). As those of
ordinary skill will recognize, alternative bladder support systems
may also be used.
[0141] For example, FIG. 14A is an illustration an exemplary
bladder system 450 comprising a bladder 480 and a bladder support
475 that is positioned within an internal bladder cavity 485
defined by the bladder 480. FIG. 14B is a cross sectional view of
the exemplary bladder system 450 illustrated in FIG. 14A. In one
preferred arrangement, the bladder 480 comprises a similar
structure as the bladder 70 illustrated in FIGS. 6 and 7.
Alternatively, the bladder 480 comprises a bladder having a
plurality of wave features, such as the exemplary bladders
described and illustrated herein with reference to FIGS. 3-10. In
yet an alternative arrangement, the bladder 480 comprises a
multilayered bladder, such as the exemplary multilayered bladders
described and illustrated herein with reference to FIGS. 11-13.
[0142] Returning to FIGS. 14 A and B, the bladder 480 comprises a
bottom wall 482, a first bladder sidewall 484 extending from the
bottom wall 482, and a second bladder sidewall 486 extending from
the bottom wall 482. A bladder top wall 488 extends from a bladder
front wall (not shown) to a bladder back wall 489 and encloses the
bladder, thereby defining an internal bladder cavity 490. The
bladder system 450 further comprises a bladder support 460
comprising a spiral or corkscrew like shaped support structure that
is positioned within the internal bladder cavity 490 defined by the
bladder 480. In this illustrated arrangement, the spiral or
corkscrew support structure 460 comprises a structure wherein a
spacing between adjacent turns of the spiral are all of uniform
length along the length L.sub.BS 485 of the bladder support 460.
For example, the spacing between a first spiral 461a and a second
spiral 461b is the same as the spacing between the second spiral
461b and a third spiral 461c. In alternative spiral shaped support
structure arrangements, spiral spacing may vary along the length
L.sub.BS 485 of the bladder support 460.
[0143] The spiral shaped bladder support 460 supports the bladder
480 between a bottom surface 470 of the bladder top wall 488 and a
top surface 472 of the bladder bottom wall 482 so as to provide a
compressive load support between the bladder top wall 488 and the
bladder bottom wall 482. Specifically, and as may be seen from FIG.
14B, a first bearing surface 464 of the flexible bladder support
460 and a second bearing surface 466 of the flexible bladder
support 460 provide the compressive load support between the bottom
surface of the bladder top wall 488 and a top surface of the
bladder bottom wall 482.
[0144] In this preferred arrangement, the bladder support 460
provides support along the entire length L.sub.B 485 of the bladder
480. However, as with the other exemplary bladder supports
disclosed herein, alternative bladder support lengths may be
provided. As just one alternative arrangement, the bladder system
450 may comprise a plurality of spiral bladder supports provided
along the length L.sub.B 485 of the bladder 480, rather than just a
single, continuous bladder support as illustrated. In yet another
bladder support arrangement, a bladder support is provided along
only a portion of the bladder length L.sub.B 485.
[0145] FIG. 15A is an illustration another bladder system 500
comprising an exemplary bladder support 510 positioned within a
bladder cavity of a bladder 530, such as the bladder 80 illustrated
in FIGS. 6 and 7. FIG. 15B is a cross sectional view of the
exemplary bladder system 500 illustrated in FIG. 15A. As
illustrated, the bladder system comprises a bladder 530 (similar to
the bladder 480 described and illustrated in FIGS. 14 A and B)
along with another exemplary bladder support 510.
[0146] Returning to FIGS. 15 A and B, the bladder 530 comprises a
bottom wall 532, a first bladder sidewall 534 extending from the
bottom wall 532, and a second bladder sidewall 536 extending from
the bottom wall 532. A bladder top wall 538 extends from a bladder
front wall (not shown) to a bladder back wall 539 and encloses the
bladder 530, thereby defining an internal bladder cavity 540.
[0147] In this illustrated arrangement, the bladder support 510
comprises a plurality of spiral or corkscrew support structures
512, 514, 516. Specifically, in this arrangement, the bladder
support comprises a first spiral support 512, a second spiral
support 514, and a third spiral support 516 wherein the second and
third spiral support structures 514, 516 comprise similar
geometries. The first spiral support structure 512 comprises a
larger geometrical configuration than the second and third support
structures 514, 516.
[0148] As illustrated, the second spiral support structure 514
resides in a nested position within a first bottom corner 542 of
the bladder 530 defined between the first bladder side wall 534 and
the bladder bottom wall 532. The third spiral support structure 516
resides in a nested position within a second bottom corner 544 of
the bladder 530 defined between the bladder second sidewall 536 and
the bladder bottom wall 532. The first spiral support structure 512
is positioned between a bottom surface 520 of the bladder top wall
538 and the first and second support structures 514, 526,
respectively. In one preferred arrangement, the first support
structure 512 comprises a larger diameter than the second and third
support structures 514, 516. However, those of ordinary skill in
the art will recognize alternative bladder support geometrical
configurations and sizes are also possible.
[0149] In this arrangement, and as may be seen from FIG. 15B, a
first bearing surface 513 of the first spiral support 512, a second
bearing surface 515 of the second spiral support 514, and a third
bearing surface 517 of the third spiral support 516 provide the
compressive load support between the bottom surface of the bladder
top wall 538 and a top surface of the bladder bottom wall 532,
respectively.
[0150] FIG. 16A is an illustration another exemplary bladder system
550 comprising a bladder support 560 positioned within a bladder
cavity 590 defined by a bladder 580, such as the bladder
illustrated in FIGS. 5 and 6. FIG. 16B is a cross sectional view of
the bladder support 560 illustrated in FIG. 16A. As illustrated,
the bladder support 560 comprises a sinusoidal structure that
extends over the length L.sub.B 581 of the bladder 580.
[0151] Returning to FIGS. 16 A and B, the bladder 580 comprises a
bottom wall 582, a first bladder sidewall 584 extending from the
bottom wall 582, and a second bladder sidewall 586 extending from
the bottom wall 582. A bladder top wall 588 extends from a bladder
front wall (not shown) to a bladder back wall 591 and encloses the
bladder 580, thereby defining an internal bladder cavity 590.
[0152] In this illustrated arrangement, the sinusoidal support
structure 560 is positioned within the bladder cavity 590 so that a
top bearing surface 562 of the support structure 560 supports a
bottom surface 570 of the bladder top wall 588. In addition, a
bottom bearing surface 564 of the support structure 560 resides
along a top surface 572 of the bladder bottom wall 582. As such, in
this support structure arrangement, and as may be seen from FIG.
16B, the top bearing surface 562 of the bladder support 560
supports the bottom surface 570 of the bladder top wall and the
bottom bearing surface 564 of the bladder support 560 provide the
compressive load support between the bottom surface of the bladder
top wall 588 and the top surface of the bladder bottom wall 582,
respectively.
[0153] As illustrated in FIGS. 16A and B, the support structure 560
comprises a constant width W.sub.SS 566 along the entire length
L.sub.BS of the bladder support 560. As those of ordinary skill in
the art will recognize, alternative sinusoidal bladder support
arrangements may also be utilized. For example, alternative
sinusoidal support structures with varying amplitudes, periods, and
support structure widths may also be provided.
[0154] For example, FIG. 17A is an illustration of yet another
exemplary sinusoidal bladder support 610 positioned within a
bladder cavity 640 defined by a bladder 630. FIG. 17B is a cross
sectional view of the bladder support 610 illustrated in FIG. 17A
positioned within the bladder cavity 640 defined by a bladder 630.
Similar to the bladder 580 illustrated in FIGS. 16A and B, the
bladder 630 comprises a bottom wall 632, a first bladder sidewall
634 extending from the bottom wall 632, and a second bladder
sidewall 636 extending from the bottom wall 632. A bladder top wall
638 extends from a bladder front wall (not shown) to a bladder back
wall 637 and encloses the bladder 630, thereby defining an internal
bladder cavity 640.
[0155] As illustrated, this bladder support 610 comprises two
separate support structures: a first sinusoidal support structure
614, similar to the sinusoidal support structure 560 illustrated in
FIGS. 16A and 16B along with a second planar bladder support 612.
In this illustrated arrangement, the second planar bladder support
612 is provided between the bladder top wall 638 and a first
bearing surface of the sinusoidal bladder support 614.
[0156] As such, in this two component support structure
arrangement, and as may be seen from FIG. 17B, a top bearing
surface 613 of the second planar bladder support 612 supports a
bottom surface 639 of the bladder top wall 638 and a bottom bearing
surface 615 of the second sinusoidal bladder support 614 provide
the compressive load support between the bottom surface 639 of the
bladder top wall 638 and the top surface 633 of the bladder bottom
wall 632, respectively.
[0157] FIG. 18A is an illustration of a yet another alternative
sinusoidal bladder support 660 that is positioned within a bladder
cavity 690 defined by a bladder 680, similar to the bladder
illustrated in FIGS. 5 and 6. FIG. 18B is a cross sectional view of
the bladder support arrangement illustrated in FIG. 18A positioned
within the cavity 690 defined by the bladder 680. The bladder 680
comprises a bottom wall 682, a first bladder sidewall 684 extending
from the bottom wall 682, and a second bladder sidewall 686
extending from the bottom wall 682. A bladder top wall 688 extends
from a bladder front wall (not shown) to a bladder back wall 689
and encloses the bladder 680, thereby defining an internal bladder
cavity 690.
[0158] In this illustrated arrangement, the sinusoidal support
structure 660 is positioned within the bladder cavity 690 so that a
top bearing surface 662 of the support structure 660 supports a
bottom surface 670 of the bladder top wall 688 and a bottom bearing
surface 664 of the support structure 660 resides along a top
surface 672 of the bladder bottom wall 682. As such, and as may be
seen from FIG. 18B, the top bearing surface 662 of the bladder
support 660 supports the bottom surface 670 of the bladder top wall
688 and the bottom bearing surface 664 of the bladder support 660
provide the compressive load support between the bottom surface 689
of the bladder top wall 688 and the top surface of the bladder
bottom wall 682, respectively.
[0159] As illustrated in FIG. 18A,B, the support structure 660
comprises a varying width W.sub.SS 666 along the entire length
L.sub.BS 668 of the bladder support 660. However, as those of
ordinary skill in the art will recognize, sinusoidal support
structures comprising alternative widths may also be used. As just
one example, a sinusoidal structure comprising a constant width
over a first portion of the bladder support length L.sub.BS along
with a varying width over a second portion of the length L.sub.BS
may also be used.
[0160] FIG. 19A is an illustration another bladder system 700
comprising a bladder support 710 positioned within a bladder cavity
740 defined by a bladder 730, such as the bladder illustrated in
FIGS. 5 and 6. FIG. 19B is a cross sectional view of the bladder
support 710 illustrated in FIG. 19A positioned within the bladder
cavity 740 defined by the bladder 730. The bladder 730 comprises a
bottom wall 732, a first bladder sidewall 734 extending from the
bottom wall 732, and a second bladder sidewall 736 extending from
the bottom wall 322. A bladder top wall 738 extends from a bladder
front wall (not shown) to a bladder back wall 739 and encloses the
bladder 730, thereby defining an internal bladder cavity 740.
[0161] As illustrated, the bladder support 710 comprises a
multi-sided bladder support. Specifically, the bladder support 710
comprises a five sided structure wherein the bladder support 710 is
positioned within the bladder cavity 740. Specifically, the bladder
support 710 is positioned so as to support a bottom surface 748 of
the bladder top wall 738, an inner surface 744 of the first bladder
side wall 734, an inner surface 746 of the second bladder side wall
736, and a top surface 742 of the bladder bottom wall 732. As such,
and as may be seen from FIG. 19B, a top bearing surface 712 of the
bladder support 710 supports the bottom surface 749 of the bladder
top wall 748, a first side bearing surface 711a of the bladder
support 710 supports the inner surface 744 of the first bladder
side wall, a second side bearing surface 711b of the bladder
support 710 supports the inner surface 746 of the second side wall
736, and a bottom bearing surface 718 of the bladder support 710
provide the compressive load support between the bladder top wall
738, the bladder side walls 734, 736, and the bladder bottom wall
732, respectively.
[0162] In one arrangement, the multi-sided bladder support 710
comprises a solid bladder support as illustrated in FIG. 19A.
However, in an alternative arrangement, the multi-sided bladder
support 710 comprises a segmented multi-walled bladder support. For
example, FIG. 20A is an illustration of yet another bladder support
system 750 wherein the bladder support comprises a segmented,
multi-sided support 760. As illustrated, the multi-sided support
760 comprises a plurality of cut-outs along a length of the support
760. Advantages of such a segmented, multi-sided support 760
include lighter weight and greater flexibility.
[0163] FIG. 21A is an illustration another bladder system 800
comprising a bladder support 810 positioned within a bladder cavity
840 defined by a bladder, such as the bladder illustrated in FIGS.
5 and 6. FIG. 21B is a cross sectional view of the bladder support
arrangement illustrated in FIG. 21A. As illustrated, the bladder
support 810 comprises a multi-sided bladder support.
[0164] As illustrated, the bladder support 810 comprises a
multi-sided bladder support. Specifically, the bladder support 810
comprises a five sided structure wherein the bladder support 810 is
positioned within the bladder cavity 840. Specifically, the bladder
support 810 is positioned so as to support a bottom surface 848 of
the bladder top wall 838, an inner surface 844 of the first bladder
side wall 834, an inner surface 846 of the second bladder side wall
836, and a top surface 842 of the bladder bottom wall 832. As such,
and as may be seen from FIG. 21B, a top bearing surface 812 of the
bladder support 810 supports the bottom surface 848 of the bladder
top wall 848, a first side bearing surface 811a of the bladder
support 810 supports the inner surface 844 of the first bladder
side wall, a second side bearing surface 811b of the bladder
support 810 supports the inner surface 846 of the second side wall
836, and a bottom bearing surface 811c of the bladder support 810
provide the compressive load support between the bladder top wall
888, the bladder side walls 834, 836, and the bladder bottom wall
832, respectively.
[0165] FIG. 22A is an illustration of another bladder system 850
comprising a bladder support 860 positioned within a bladder cavity
890 defined by a bladder 880, such as the bladder illustrated in
FIGS. 5 and 6. FIG. 22B is a cross sectional view of the bladder
support 860 illustrated in FIG. 22A positioned within the cavity
formed by the bladder 880. The bladder 880 comprises a bottom wall
882, a first bladder sidewall 884 extending from the bottom wall
882, and a second bladder sidewall 886 extending from the bottom
wall 882. A bladder top wall 888 extends from a bladder front wall
(not shown) to a bladder back wall 889 and encloses the bladder
880, thereby defining an internal bladder cavity 890.
[0166] As illustrated, the bladder support 860 comprises a double
concave support. This double concave bladder 860 comprises both a
top bearing surface 862 and a bottom bearing surface 864. This
bladder support 860 further comprises a first side support 866 and
a second side support 868. Specifically, the first side support 866
extends in a concave manner from a first end 863a of the bottom
bearing surface 864 to a first end 861a of the top bearing surface
862. Similarly, the second side support 868 extends in a concave
manner from a second end 863b of the bottom bearing surface 864
upwards towards a second end 861b of the top bearing surface 862.
In this manner, a top surface of the top bearing surface 862
provides support along a bottom surface of the bladder top wall
888. In addition, a bottom bearing surface of the bottom support
864 provides bladder support to the top surface of the bladder
bottom wall 882.
[0167] As such, and as may be seen from FIG. 22B, a top bearing
surface 862 of the bladder support 860 supports the bottom surface
of the bladder top wall 888 and a bottom bearing surface 864 of the
bladder support 860 is provided along a top surface of the bladder
bottom wall 832 so as to provide the compressive load support
between the bladder top wall 888 and the bladder bottom wall 832,
respectively.
[0168] As illustrated in FIG. 22B, the top bearing surface 862
comprises a surface width W.sub.TBS 863 that is generally larger
than a width W.sub.BBS 865 of the bottom bearing surface 864. As
those of ordinary skill will recognize, alternative supporting
width structures may also be provided.
[0169] As illustrated in FIG. 22A, the double concave bladder
support 860 comprises a continuous structure. In an alternative
arrangement, the double concave bladder support may comprise a
double concave segmented bladder support. For example, FIG. 23A is
an illustration a segmented double concave bladder support 900
positioned within a bladder 930, such as the bladder illustrated in
FIGS. 5 and 6. FIG. 23B is a cross sectional view of the segmented
double concave bladder support 930 illustrated in FIG. 25A.
Advantages of such a segmented bladder support include lighter
weight and greater flexibility.
[0170] FIG. 24A is an illustration another bladder system 950
comprising a bladder support 960 positioned within a bladder cavity
990 defined by a bladder 980, such as the bladder illustrated in
FIGS. 5 and 6. FIG. 24B is a cross sectional view of the bladder
support 960 illustrated in FIG. 24A positioned within the cavity
defined by the bladder 980. The bladder 980 comprises a bottom wall
982, a first bladder sidewall 984 extending from the bottom wall
982, and a second bladder sidewall 986 extending from the bottom
wall 982. A bladder top wall 988 extends from a bladder front wall
(not shown) to a bladder back wall 989 and encloses the bladder
980, thereby defining an internal bladder cavity 990.
[0171] As illustrated, the bladder support 960 comprises a
multi-sided structure wherein the multi-sided structure comprise a
top bearing surface 962 and a bottom wall 966. As illustrated, the
top bearing surface comprises a width W.sub.TBS 963 and the bottom
wall 966 comprises a width W.sub.BS 967 wherein the bottom side
width W.sub.Bs 967 is greater than the top side width W.sub.TS
963.
[0172] As illustrated, the bladder support 960 comprises a
multi-sided bladder support. Specifically, the bladder support 960
comprises a four sided structure wherein the bladder support 960 is
positioned within the bladder cavity 990. As illustrated, the
bladder support 960 is positioned so as to support a bottom surface
of the bladder top wall 988, an inner surface 985 of the first
bladder side wall 984, and an inner surface 987 of the second
bladder side wall 986. As such, and as may be seen from FIG. 24B,
the top bearing surface 962 of the bladder support 960 supports the
bottom surface of the bladder top wall 988, a first side bearing
surface 965 of the bladder support 960 supports an inner surface
985 of the first bladder side wall 984, and a second side bearing
surface 969 of the bladder support 960 supports an 987 inner
surface of the second side wall 986, such that the bladder support
960 provides the compressive load support between the bladder top
wall 988, and the bladder side walls 984, 986, respectively.
[0173] As illustrated, the multi-sided support 950 illustrated in
FIG. 24A comprises a non-segmented structure. However, in an
alternative arrangement, the multi-sided bladder support 950
comprises a segmented bladder support. For example, FIG. 25A is an
illustration a segmented multi-walled structure bladder support
1010 positioned within a bladder cavity 1040 defined by a bladder
1030, such as the bladder illustrated in FIGS. 5A and 5B. FIG. 25B
is a cross sectional view of the bladder support 1010 illustrated
in FIG. 25A positioned within the bladder cavity 1040.
[0174] FIG. 26A is an illustration another bladder system 1050
comprising a bladder support 1060 positioned within a bladder
cavity 1090 defined by a bladder 1080, such as the bladder
illustrated in FIGS. 5 and 6. FIG. 26B is a cross sectional view of
the bladder support arrangement illustrated in FIG. 26A. The
bladder 1080 comprises a bottom wall 1082, a first bladder sidewall
1084 extending from the bottom wall 1082, and a second bladder
sidewall 1086 extending from the bottom wall 1082. A bladder top
wall 1088 extends from a bladder front wall (not shown) to a
bladder back wall 1089 and encloses the bladder 1080, thereby
defining an internal bladder cavity 1090.
[0175] As illustrated, the bladder support 1060 comprises a main
support portion 1062, a first support leg 1064, and a second
support leg 1066. The support first leg 1064 comprises a first leg
portion 1065a and a second leg portion 1065b. In this illustrated
arrangement, the second leg portion 1065b is longer than the first
leg portion 1065a. Similarly, the second support leg 1066 comprises
a first leg portion 1067a and a second leg portion 1067b. In this
illustrated arrangement, the second leg portion 1067b is longer
than the first leg portion 1067a.
[0176] As illustrated in FIG. 26B, when providing support to the
bladder 1080, an outer surface 1063 of the first support leg 1064
resides along an inner surface of the bladder first side wall 1084
while an outer surface 1068 of the second leg 1066 resides along an
inner surface of the bladder second side wall 1086. In this
illustrated arrangement, the main portion 1062 of the bladder
support 1060 is bowed in a convex shape so that an upper surface of
the bladder support main portion 1060 provides support to a bottom
surface of the bladder top wall.
[0177] As such, and as may be seen from FIG. 26B, a top bearing
surface 1063 of the bladder support main portion 1060 supports the
bottom surface 1098 of the bladder top wall 1088, the first support
leg 1064 supports the inner surface 1094 of the first bladder side
wall 1084, and a second support leg 1064 supports the inner surface
1096 of the second side wall 1086, such that the bladder support
1060 provides the compressive load support between the bladder top
wall 1088, and the bladder side walls 1084, 1086, respectively.
[0178] FIG. 27A is an illustration another bladder system 1100
comprising a bladder support 1110 positioned within a bladder
cavity 1140 defined by a bladder 1030, such as the bladder
illustrated in FIGS. 5 and 6. FIG. 27B is a cross sectional view of
the bladder support arrangement illustrated in FIG. 27A. The
bladder 1130 comprises a bottom wall 1132, a first bladder sidewall
1134 extending from the bottom wall 1132, and a second bladder
sidewall 1136 extending from the bottom wall 1132. A bladder top
wall 1138 extends from a bladder front wall (not shown) to a
bladder back wall 1139 and encloses the bladder 1130, thereby
defining an internal bladder cavity 1140.
[0179] In this illustrated arrangement, the bladder support 1110
comprises a plurality of cylindrical support structures 1112a-d,
1114. Specifically, in this arrangement, the bladder support
comprises a plurality of first and a plurality of second
cylindrical support structures wherein the first and second
cylindrical support structures comprise a similar geometrical
configuration. For example, and as illustrated in FIG. 27B, the
cylindrical support structure
[0180] The third spiral like support structure comprises a larger
geometrical configuration than the first and second support
structures.
[0181] In this illustrated arrangement, the bladder support 1110
comprises a plurality of cylindrical supports 1112, 1114, 1116,
1118, and 1119. Specifically, in this arrangement, the bladder
support 1110 comprises a first plurality of cylindrical supports
1112, a second plurality of cylindrical supports 1114, a third
plurality of cylindrical supports 1116, a fourth plurality of
cylindrical supports 1119. In this preferred arrangement, the
first, second, fourth and fifth cylindrical support structures
comprise similar cylindrical geometries. The third spiral support
structure 1119 comprises a smaller geometrical configuration than
the first, second, fourth and fifth cylindrical supports.
[0182] As illustrated in FIG. 27B, the first cylindrical support
1112 resides in a nested position within a first bottom corner 1142
of the bladder 1130 defined between the first bladder side wall
1134 and the bladder bottom wall 1132. Similarly, the second
cylindrical support structure 1114 resides in a nested position
within a second bottom corner 1144 of the bladder 1130 defined
between the bladder second sidewall 1136 and the bladder bottom
wall 1132.
[0183] The third cylindrical support structure 1119 is nested
between the first and second support structures 1112, 1114. The
fourth and fifth cylindrical supports 1116, 1118 are then
positioned between a bottom surface 1133 of the bladder top wall
1132 and the first and second support structures 1112, 1114,
respectively. In one preferred arrangement, the third cylindrical
support 1119 comprises a smaller diameter than the first, second,
fourth and fifth cylindrical supports 1112, 1114, 1116, and 1118.
However, those of ordinary skill in the art will recognize
alternative bladder support geometrical configurations and sizes
are also possible.
[0184] In this arrangement, and as may be seen from FIG. 27B, a
bearing surface 1113 of the first cylindrical support 1112, a
bearing surface 1115 of the second cylindrical support 1114, a
bearing surface 1117 of the fourth cylindrical support 1116 and a
bearing surface 1117 provide the compressive load support between
the bottom surface 1133 of the bladder top wall 1132 and a top
surface 1133 of the bladder bottom wall 1132, respectively.
[0185] FIG. 28A is an illustration another bladder system 1150
comprising a bladder support 1160 positioned within a bladder
cavity of a bladder, such as the bladder illustrated in FIGS. 5A
and 5B. FIG. 28B is a cross sectional view of the bladder support
1160 illustrated in FIG. 18A positioned within the bladder cavity
1190 defined by the bladder 1180. The bladder 1180 comprises a
bottom wall 1182, a first bladder sidewall 1184 extending from the
bottom wall 1182, and a second bladder sidewall 1186 extending from
the bottom wall 1182. A bladder top wall 1188 extends from a
bladder front wall (not shown) to a bladder back wall 1189 and
encloses the bladder 1180, thereby defining an internal bladder
cavity 1190.
[0186] As illustrated, the bladder support 1160 comprises a
multi-sided bladder support. In this illustrated multi-sided
bladder support, the bladder support 1160 comprises a six sided
structure wherein the bladder support 1160 is positioned within the
bladder cavity 1190. Specifically, the bladder support 1160 is
positioned so as to support a bottom surface 1182 of the bladder
top wall 1188, an inner surface 1185 of the first bladder side wall
1184, an inner surface 1187 of the second bladder side wall 1186,
and a top surface 1183 of the bladder bottom wall 1182. As such,
and as may be seen from FIG. 28B, a top bearing surface 1162 of the
bladder support 1160 supports the bottom surface 1182 of the
bladder top wall 1188, a first side bearing surface of the bladder
support 1160 supports the inner surface 1185 of the first bladder
side wall 1184, a second side bearing surface 1168 of the bladder
support 1160 supports the inner surface 1187 of the second bladder
side wall 1186, and a bottom bearing surface 1166 of the bladder
support 1160 provide the compressive load support between the
bladder top wall 1188, the bladder side walls 1184, 1186, and the
bladder bottom wall 1182, respectively.
[0187] In one arrangement, the multi-sided bladder support 1160
comprises a segmented bladder support as illustrated in FIG. 28A.
In such a segmented bladder support arrangement, a plurality of
slots are provided along a length of the bladder support 1160. In
an alternative arrangement, the multi-sided bladder support 1160
comprises a solid or a non-segmented multi-walled bladder
support.
[0188] FIG. 29A is an illustration another spiral bladder support
1260. FIG. 29B is a cross sectional view of the spiral bladder
support 1260 illustrated in FIG. 29A positioned within a bladder
cavity 1290 defined by a bladder 1280. The bladder 1280 comprises a
bottom wall 1282, a first bladder sidewall 1284 extending from the
bottom wall 1282, and a second bladder sidewall 1286 extending from
the bottom wall 1282. A bladder top wall 1288 extends from a
bladder front wall (not shown) to a bladder back wall (not shown)
and encloses the bladder 1280, thereby defining an internal bladder
cavity 1290.
[0189] As illustrated, the spiral bladder support 1260 comprises a
multi-sided bladder support in the form of a continuous spiral. In
this illustrated multi-sided bladder support, the spiral bladder
support 1260 comprises a six sided structure wherein the bladder
support 1260 is positioned within the bladder cavity 1290.
Specifically, the spiral bladder support 1260 is positioned so as
to support a bottom surface 1282 of the bladder top wall 1288, an
inner surface 1285 of the first bladder side wall 1284, an inner
surface 1287 of the second bladder side wall 1286, and a top
surface 1283 of the bladder bottom wall 1282. As such, and as may
be seen from FIG. 29B, a top bearing surface 1262 of the spiral
bladder support 1260 supports the bottom surface 1282 of the
bladder top wall 1288, a first side bearing surface of the spiral
bladder support 1260 supports the inner surface 1285 of the first
bladder side wall 1284, a second side bearing surface 1268 of the
bladder support 1260 supports the inner surface 1287 of the second
bladder side wall 1286, and a bottom bearing surface 1266 of the
bladder support 1260 provide the compressive load support between
the bladder top wall 1288, the bladder side walls 1284, 1286, and
the bladder bottom wall 1282, respectively.
[0190] In one arrangement, a top bearing surface 1262 of the spiral
bladder support 1260 comprises a crowned top bearing surface 1262
comprising an upwardly extending convex shape. Such a crowned top
bearing surface 1262 would have a first height at room temperature
that is equal to a second height at a cure temperature. As such,
the crowned top bearing surface would support the bottom surface of
the bladder top wall 1288 at room temperature. In addition, at the
higher cure temperature, the crowned top bearing surface 1262 would
continue to support the bottom surface of the bladder top wall 1288
since at the cure temperature the coefficient of thermal expansion
of the bladder 1280 would extend to the design dimensions of the
cavity. Advantageously, the crowned top bearing surface 1262 would
continue to provide support to the top wall of the bladder 1280
even at higher cure temperatures.
[0191] In one arrangement, the spiral bladder support 1260
comprises an even segmented spiral bladder support wherein a
spacing between adjacent spiral portions are generally equal to one
another. In one arrangement, the spiral bladder support 1260
comprises a spiral comprising a continuous width along the entire
length of the spiral bladder support.
[0192] FIG. 30A is an illustration another spiral bladder support
1360. FIG. 30B is a cross sectional view of the spiral bladder
support 1360 illustrated in FIG. 30A positioned within a bladder
cavity 1390 defined by the bladder 1380. The bladder 1380 comprises
a bottom wall 1382, a first bladder sidewall 1384 extending from
the bottom wall 1382, and a second bladder sidewall 1386 extending
from the bottom wall 1382. A bladder top wall 1388 extends from a
bladder front wall (not shown) to a bladder back wall (not shown)
and encloses the bladder 1380, thereby defining an internal bladder
cavity 1390.
[0193] As illustrated, the spiral bladder support 1360 comprises a
multi-sided bladder support in the form of a continuous spiral. In
this illustrated multi-sided bladder support, the spiral bladder
support 1360 comprises a six sided structure wherein the bladder
support 1360 is positioned within the bladder cavity 1390.
Specifically, the spiral bladder support 1360 is positioned so as
to support a bottom surface 1382 of the bladder top wall 1388, an
inner surface 1385 of the first bladder side wall 1384, an inner
surface 1387 of the second bladder side wall 1386, and a top
surface 1383 of the bladder bottom wall 1382. As such, and as may
be seen from FIG. 30B, a top bearing surface 1362 of the spiral
bladder support 1360 supports the bottom surface 1382 of the
bladder top wall 1388, a first side bearing surface of the spiral
bladder support 1360 supports the inner surface 1385 of the first
bladder side wall 1384, a second side bearing surface 1368 of the
bladder support 1360 supports the inner surface 1387 of the second
bladder side wall 1386, and a bottom bearing surface 1366 of the
bladder support 1360 provide the compressive load support between
the bladder top wall 1388, the bladder side walls 1384, 1386, and
the bladder bottom wall 1382, respectively.
[0194] In one arrangement, the spiral bladder support 1360
comprises an even segmented spiral bladder support wherein a
spacing between adjacent spiral portions are generally equal to one
another. In one arrangement, the spiral bladder support 1360
comprises a spiral comprising a continuous width along the entire
length of the spiral bladder support 1360. In one arrangement, a
slot is provided within each spiral segment of the spiral bladder
support 1360. As illustrated, the plurality of slots provided in
the plurality of spiral bladder support segments are all of uniform
shape and dimensions. However, in alternative spiral bladder
support arrangements, different sized slots and slot configurations
may also be used.
[0195] FIG. 31A is an illustration another bladder support in the
form of a spiral bladder support 1450. FIG. 31B is an illustration
of a bladder support system 1460 comprising the spiral bladder
support 1450 positioned within a bladder cavity 1490 of a bladder
1480, such as the bladder illustrated in FIGS. 5A and 5B. FIG. 31C
is a cross sectional view of the spiral bladder support 1450
illustrated in FIG. 31B positioned within the bladder cavity 1490
defined by the bladder 1480. The bladder 1480 comprises a bottom
wall 1482, a first bladder sidewall 1484 extending from the bottom
wall 1482, and a second bladder sidewall 1486 extending from the
bottom wall 1482. A bladder top wall 1488 extends from a bladder
front wall (not shown) to a bladder back wall (not shown) and
encloses the bladder 1480, thereby defining an internal bladder
cavity 1490.
[0196] As illustrated, the spiral bladder support 1450 comprises a
multi-sided bladder support in the form of a continuous spiral. In
this illustrated multi-sided bladder support, the spiral bladder
support 1450 comprises a six sided structure wherein the bladder
support 1450 is positioned within the bladder cavity 1490.
Specifically, the spiral bladder support 1450 is positioned so as
to support a bottom surface 1482 of the bladder top wall 1488, an
inner surface 1485 of the first bladder side wall 1484, an inner
surface 1487 of the second bladder side wall 1486, and a top
surface 1483 of the bladder bottom wall 1482. As such, and as may
be seen from FIG. 31C, a top bearing surface 1462 of the spiral
bladder support 1460 supports the bottom surface 1482 of the
bladder top wall 1488, a first side bearing surface of the spiral
bladder support 1450 supports the inner surface 1485 of the first
bladder side wall 1484, a second side bearing surface 1468 of the
bladder support 1450 supports the inner surface 1487 of the second
bladder side wall 1486, and a bottom bearing surface 1466 of the
bladder support 1460 provide the compressive load support between
the bladder top wall 1488, the bladder side walls 1484, 1486, and
the bladder bottom wall 1482, respectively.
[0197] In one arrangement, the spiral bladder support 1450
comprises an even segmented spiral bladder support wherein a
spacing S between adjacent spiral portions is generally equal to
one another. In the spiral bladder support 1450 illustrated in
FIGS. 31A-C, this spacing S 1451 (FIG. 31A) between adjacent spiral
portions can be increased or decreased depending on the bladder
support application. For example, the spacing S 1451 of the bladder
support 1450 is generally greater than the spacing of the spiral
bladder supports illustrated in FIGS. 29 and 30.
[0198] FIG. 32A illustrates a perspective view of a multi-segmented
articulated bladder support 1550. As illustrated, the
multi-segmented bladder support 1550 comprises a plurality of
bladder segments 1560 joined to one another. As illustrated, the
plurality of bladder segments 1560 are fixedly attached to one
another by way of a joining member, such as joining member 1570. In
this illustrated arrangement, the joining member 1570 comprises a
cross joining member. As also illustrated, each bladder support
segment within the plurality of segments 1560 comprises a four
sided support structure that is joined to an adjacent four sided
bladder support segment by way of the cross joining member.
[0199] To enable joining adjacent bladder support segments, each
bladder support segment comprises two vertically oriented, forward
facing arm segments. For example, bladder support segment 1560A
comprises two vertically oriented, forward facing arm segments
1562A, B. Each of these forward facing arm segments define a
receiving cavity. For example, first vertically oriented, forward
facing arm segment 1562A defines a first receiving cavity 1566A and
the second vertically oriented, forward facing arm segment 1562B
defines a second receiving cavity 1566B.
[0200] In addition, each bladder support segment comprises two
horizontally oriented, rearward facing arm segments. For example,
bladder support segment 1560 comprises two horizontally oriented,
rearward facing arm segments 1570A,B. Each of these rearward facing
arm segments define a receiving cavity. For example, first
horizontally oriented, rearward facing arm segment 1572A defines a
first receiving cavity 1574A and second horizontally oriented,
rearward facing arm segment 1570B defines a second receiving cavity
1574B.
[0201] When the various adjacent support segments 1560 are joined
to another so as to define the articulated bladder support 1550,
the arms of the cross joining member 1570 engage the forward
vertically oriented arm segments 1562A, B of the bladder support
segment and the top and bottom portions of the cross joining member
1570 engage the rearward, horizontally facing arm segments of a
second bladder support segment residing adjacent the first bladder
support segment 1560.
[0202] FIG. 32B illustrates a perspective view of an alternative
multi-segmented articulated bladder support 1580 similar in
structure to the bladder support 1550 illustrated in FIG. 32A. As
illustrated, the multi-segmented bladder support comprises a
plurality of bladder supports 1588 that are operatively coupled to
one another by way of a joining member 1586. However, one
difference between the bladder support 1550 and the bladder support
1580 is that bladder support 1580 utilizes a star joining member
1586 to join the adjacent bladder support segments making up the
bladder support.
[0203] That is, when the various adjacent support segments 1588 are
joined to another so as to define the articulated bladder support
1580, the arms of the star joining member 1586 engage forward
vertically oriented arm segments of the bladder support segment and
the top and bottom portions of the star joining member 1586 engage
the rearward, horizontally facing arm segments of a second bladder
support segment residing adjacent the first bladder support segment
1580.
[0204] FIG. 32C illustrates a perspective view of a multi-segmented
articulated bladder support 1650. As illustrated, the
multi-segmented articulated bladder support 1650 comprises a
plurality of bladder segments 1660A-B that are fixedly attached to
one another by way of a joining member 1680. In this illustrated
arrangement, the joining member 1680 comprises a ring joining
member. As also illustrated, each bladder support segment 1660A-C
comprises a four sided support structure wherein each of these
bladder support segments are joined to an adjacent bladder support
segment by way of a ring joining member.
[0205] To enable joining adjacent bladder support segments, each
bladder support segment 1660A-C comprises two vertically oriented,
forward facing arm segments. For example, the first bladder support
segment 1660A comprises a first forward facing arm segment 1662A
and a second vertically oriented, forward facing arm segment 1662
B. Each of these forward facing arm segments 1662 A,B define a
receiving cavity. For example, the first vertically oriented,
forward facing arm segment 1662A defines a first receiving cavity
1666A and the second vertically oriented, forward facing arm
segment 1662B defines a second receiving cavity 1662B.
[0206] Similarly, each bladder support segment 1660A-C comprises
two horizontally oriented, rearward facing arm segments. In
addition, each of these rearward facing arm segments define a
receiving cavity. For example, first horizontally oriented,
rearward facing arm segment 1670A of the first bladder support
segment 1660A defines a first receiving cavity 1674A. Similarly,
the second horizontally oriented, rearward facing arm segment 1670B
of the first bladder support segment 1660A defines a second
receiving cavity. (not shown in FIG. 32C). The second and third
bladder support elements 1660B and 1660C comprise similar
structures.
[0207] As also illustrated in FIG. 32C, the ring joining member
1680 comprises a generally circular geometry. Along an outside
surface of the ring joining member 1680, a plurality of radially
extending protrusions are provided. For example, in the ring
joining member arrangement illustrated in FIG. 32C, four equally
spaced radially extending protrusions are provided along an outer
surface of the ring joining member 1680. In FIG. 32C, only two of
these radially extending protrusions 1682 and 1688 are
illustrated.
[0208] When the various adjacent support segments 1660 A-C are
joined to another so as to define the articulated bladder support
1650 as illustrated in FIG. 32C, two of the protrusions of the ring
joining member 1680 engage the forward vertically oriented arm
segments 1562A,B of the second support segment 1660B and two of the
pegs of the ring joining member 1680 engage the horizontally
oriented, rearward facing arm segments of the first bladder support
segment 1660A residing adjacent the second bladder support segment
1660B.
[0209] FIG. 32D illustrates a perspective view of a multi-segmented
articulated bladder support 1750. As illustrated, the
multi-segmented articulated bladder support 1750 comprises a
plurality of bladder segments 1760A-C that are fixedly attached to
one another. In this illustrated arrangement, each bladder support
segment 1760A-C comprises a four sided support structure that are
joined to one another by way of a ball and socket member
arrangement as herein described.
[0210] For example, the first bladder support segment 1760A
comprises three arms that extend from a first surface 1764 of the
bladder support segment 1760A. These three arms 1762A-C extend away
from the first surface 1764 and support a first socket member
1766A. Similarly, the first bladder support segment 1760A comprises
three arms 1772A-C that extend from a second surface 1774 of the
bladder support segment 1760A. These three arms 1772A-C extend away
from the second surface 1774 and support a second socket member
1776B. The third bladder support segment 1760C within the
illustrated bladder support 1750 of FIG. 32D comprises a similar
first and second socket member arrangement.
[0211] The second bladder support segment 1760B is of similar
configuration to the first and second bladder support segments
1760A and 1760C. However, rather than comprise first and second
socket members, the second bladder support segment 1760B comprises
a first and second ball member arrangement.
[0212] For example, the second bladder support segment 1760B
comprises three arms 1782A-C that extend from a first surface 1784
of the second bladder support segment 1760B. These three arms
1782A-C extend away from the first surface 1784 to support a first
ball member 1780. Similarly, the second bladder support segment
1760B further comprises three arms 1792A-C that extend from a
second surface 1794 of the second bladder support segment 1760B.
These three arms 1792A-C extend away from the second surface 1794
so as to support a second ball member 1790.
[0213] When the various adjacent support segments 1760A-C are
joined to another so as to define the articulated bladder support
1750 as illustrated in FIG. 32D, the first ball member 1780 of the
second support segment 1760B is removably coupled to the second
1776B of the first support segment. Similarly, the second ball
member 1790 of the second support segment 1760B is removably joined
to a first of the third support segment 1760C.
[0214] One advantage of utilizing an articulated bladder support
structure, such as those articulated bladder support structures
illustrated in FIGS. 32-34, is their ease of manufacturing. That
is, a single bladder support segment, such as the bladder support
segments 1588 can manufactured and then the final bladder support
structure can be assemble to a specific or desired length,
depending on the application.
[0215] Attention is now directed to FIG. 33 which broadly
illustrates steps of a method 2000 for autoclave curing using a
bladder system comprising a bladder support, such as the bladder
supports described above with reference to FIGS. 14-32. For
example, and beginning at step 2002, a composite resin charge is
supported within an autoclave by being placed on a suitable tool,
such as the cure tool 15 discussed with reference to FIG. 1. At
step 2004, forming aids (not shown) may be used to press the
various plies making up the charge down into the mold cavity, and
conform the charge to radii in the mold cavity.
[0216] At step 2006, a bladder is positioned into the tool cavity
over the charge. Such a bladder may comprise wave features as
disclosed herein. In addition, such a bladder may comprise a
multilayered bladder system as described herein. At step 2008, a
bladder support is positioned into a cavity defined by the
bladder.
[0217] At step 2010, plies are laid by a machine over the bladder
creating a head pressure on the bladder. At step 2012, the bladder
support provides a compressive load support between the plies being
laid by the machine and the bladder itself. At step 2014, the
bladder may be coupled to a vent port. Such a venting port allows
the bladder to be inflated to a desired pressure and also allows
the bladder to inflate to a desired cross section size. Such a
venting port 176 is illustrated in FIGS. 7 and 9. At step 2016, the
composite charge along with the bladder are covered with a flexible
bag such as the vacuum bag 25 illustrated in FIG. 1. The vacuum bag
may then be sealed to the cure tool. At step 2018, a vacuum within
the vacuum bag is drawn.
[0218] At step 2020, the debulk process is initiated wherein
autoclave pressure P.sub.A is applied to the vacuum bag in order to
initiate compression of the various plies making up the charge. In
addition, autoclave pressure P.sub.A is also initially applied to
an interior or cavity of the bladder by way of the venting port,
pressurizing the bladder so as to react to forces applied to the
composite charge by autoclave pressure.
[0219] At step 2022, the interior of the bladder is internally
pressurized with autoclave pressure P.sub.A. This internal
pressurization of the bladder causes a force P.sub.A to be applied
to the composite charge. Therefore, the composite charge being
molded can be cured in the autoclave while the bladder maintains
its inflated state at this desired cross section size. An increased
bladder cross section size helps to ensure, that during the curing
and molding process, the outer surface of the composite charge will
be forced against respective tool surfaces of the tool. This also
increases the effective pressure applied to the inside radii of the
charge.
[0220] At step 2024, debulking of the charge continues under the
application of heat. Debulking continues by compacting or squeezing
out air and volatiles between plies or prepreg laminates of the
charge under moderate heat and vacuum so as to insure seating on
the tool, to prevent wrinkles, and to promote adhesion. At step
2026, when curing is complete, the autoclave pressure P.sub.A is
removed from the vacuum bag, and therefore is also removed from the
interior of the bladder.
[0221] FIG. 34 is an illustration of a perspective view of an
aircraft 2100 that may incorporate one or more composite laminate
structures manufactured by one of the bladder system arrangements
of the present disclosure. As shown in FIG. 34, the aircraft 2100
comprises a fuselage 2112, a nose 2114, a cockpit 2116, wings 2118
operatively coupled to the fuselage 2120, one or more propulsion
units 2120, a tail vertical stabilizer 2122, and one or more tail
horizontal stabilizers 2124. Although the aircraft 2100 shown in
FIG. 34 is generally representative of a commercial passenger
aircraft, the one or more composite laminates, as disclosed herein,
may also be employed in other types of aircraft or air vehicles.
More specifically, the teachings of the disclosed arrangements may
be applied to other passenger aircraft, cargo aircraft, military
aircraft, rotorcraft, and other types of aircraft or aerial
vehicles, as well as aerospace vehicles, satellites, space launch
vehicles, rockets, and other aerospace vehicles. It may also be
appreciated that arrangements of structures and methods in
accordance with the disclosure may be utilized in other transport
vehicles, such as boats and other watercraft, trains, automobiles,
trucks, buses, or other suitable transport vehicles formed from or
utilizing the composite laminates as disclosed herein.
[0222] Arrangements of the disclosure may find use in a variety of
potential applications, particularly in the transportation
industry, including for example, aerospace, marine, automotive
applications and other application where thermoplastic composite
structures may be used. Therefore, referring now to FIGS. 35 and
36, arrangements of the disclosure may be used in the context of an
aircraft manufacturing and service method 2130 as shown in FIG. 34
and an aircraft 2150 as shown in FIG. 36. Aircraft applications of
the disclosed arrangements may include, for example, without
limitation, the design and fabrication of composite laminates
fabricated by way of one or more of the various bladder systems as
disclosed herein.
[0223] During pre-production, exemplary method 2130 may include
specification and design 2132 of the aircraft 2150 and material
procurement 2134. As just one example, for the specification and
design of the aircraft related composite laminates, the desired
engineering characteristics of the bladder system may be determined
at this step. This might include the selection of bladder system
type for manufacturing a composite laminate that requires a cavity,
such as the stringer illustrated in FIG. 2. Such a bladder system
may comprise a bladder system comprising wave features, a
multilayered bladder system, a bladder system utilizing a bladder
support, or perhaps a combination thereof.
[0224] As another example, during this specification and design
step, in one particular bladder system arrangement, the type of
wave features may be selected. In yet another example, during this
specification and design step, if a multilayered bladder system is
selected, the thickness of the bladder inner layer or bladder outer
layer and/or whether inner layer and outer layer overlaps may be
determined. In addition, during this specification and design step,
the use of one or more bladder supports may be determined. As just
another example, at this design step, it may be determined that a
combination of a bladder wave features, a multilayered bladder
system, and a bladder support are to be employed in the
manufacturing the composite laminate.
[0225] During production, component and subassembly manufacturing
2136 and system integration 2138 of the aircraft 2150 takes place.
After such a component and subassembly manufacturing step, the
aircraft 2150 may go through certification and delivery 2140 in
order to be placed in service 2142. While in service by a customer,
the aircraft 2150 is scheduled for routine maintenance and service
2144, which may also include modification, reconfiguration,
refurbishment, and so on.
[0226] Each of the process steps of method 2150 may be performed or
carried out by a system integrator, a third party, and/or an
operator (e.g., a customer). For the purposes of this description,
a system integrator may include without limitation any number of
aircraft manufacturers and major-system subcontractors; a third
party may include without limitation any number of vendors,
subcontractors, and suppliers; and an operator may be an airline,
leasing company, military entity, service organization, and so
on.
[0227] As shown in FIG. 36, the aircraft 2150 produced by exemplary
method 2130 may include an airframe 2152 with a plurality of
high-level systems 2154 and an interior 2156. Examples of
high-level systems 2154 may include one or more of a propulsion
system 2158, an electrical system 2160, a hydraulic system 2162,
and an environmental system 2164. Any number of other systems may
be included. Although an aerospace example is shown, the principles
of the disclosure may be applied to other industries, such as the
marine and automotive industries.
[0228] Systems and methods embodied herein may be employed during
any one or more of the stages of the production and service method
2130. For example, components or subassemblies corresponding to
production process may be fabricated or manufactured in a manner
similar to components or subassemblies produced while the aircraft
2150 is in service. Also, one or more apparatus arrangements,
method arrangements, or a combination thereof may be utilized
during the production stages 2132 and 2134, for example, by
substantially expediting assembly of or reducing the cost of an
aircraft 2150. Similarly, one or more of apparatus arrangements,
method arrangements, or a combination thereof may be utilized while
the aircraft 2150 is in service, for example and without
limitation, to maintenance and service 2144.
[0229] The description of the different advantageous arrangements
has been presented for purposes of illustration and description,
and is not intended to be exhaustive or limited to the arrangements
in the form disclosed. Many modifications and variations will be
apparent to those of ordinary skill in the art. Further, different
advantageous arrangements may provide different advantages as
compared to other advantageous arrangements. The arrangement or
arrangements selected are chosen and described in order to best
explain the principles of the arrangements, the practical
application, and to enable others of ordinary skill in the art to
understand the disclosure for various arrangements with various
modifications as are suited to the particular use contemplated.
* * * * *