U.S. patent application number 14/513184 was filed with the patent office on 2015-04-16 for repair and preventive maintenance system and method for fiberglass boats.
The applicant listed for this patent is Stephan DeTurris. Invention is credited to Stephan DeTurris.
Application Number | 20150101733 14/513184 |
Document ID | / |
Family ID | 35449275 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150101733 |
Kind Code |
A1 |
DeTurris; Stephan |
April 16, 2015 |
REPAIR AND PREVENTIVE MAINTENANCE SYSTEM AND METHOD FOR FIBERGLASS
BOATS
Abstract
A method for preventive maintenance of a boat hull to restore
the integrity of a fiberglass boat hull and prevent new water
infiltration damage to a boat hull. The wet area repair guidelines
using a surface moisture meter. Any balsa cored area reading 15% or
above is considered a wet area. Any wood cored area reading 20% or
above is considered a wet area. The preventive maintenance steps
involve removing all through-hull fittings or hardware. Wet core
areas are then dried out using heat lamps, lights or heaters,
hot-vac systems, or octopus vacuum with grid system. If necessary,
any area not drying out is de-cored and repaired accordingly. After
repairs are finished, all through-hull fillings or hardware is
reinstalled using new sealant.
Inventors: |
DeTurris; Stephan; (Islip
Terrace, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DeTurris; Stephan |
Islip Terrace |
NY |
US |
|
|
Family ID: |
35449275 |
Appl. No.: |
14/513184 |
Filed: |
October 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13723044 |
Dec 20, 2012 |
8858747 |
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14513184 |
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11890270 |
Aug 4, 2007 |
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13723044 |
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10857834 |
Jun 2, 2004 |
7252727 |
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11890270 |
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Current U.S.
Class: |
156/64 |
Current CPC
Class: |
B29L 2031/307 20130101;
B29C 73/26 20130101; B29C 73/02 20130101; B63B 73/00 20200101; B63B
81/00 20200101; B63B 71/00 20200101 |
Class at
Publication: |
156/64 |
International
Class: |
B63B 9/06 20060101
B63B009/06 |
Claims
1. A method of treatment for a boat hull, said boat hull having
inner and outer fiberglass skins separated by a balsa wood core in
the form of small separated blocks preattached to a fabric like
material on one side only of said separate blocks of balsa wood,
said method comprising the steps of: a) inspecting predetermined
areas of said hull, b) inspecting said predetermined areas of said
hull for any moisture damaged balsa wood core, c) detecting any
moisture damaged balsa wood core areas of the hull, d) boring at
least one small hole through a skin at each detected moisture
damaged balsa wood core detected area; e) drying each of the
detected moisture damaged balsa wood core areas for drying out said
blocks of the balsa wood within said detected moisture damaged
balsa wood core areas; f) after drying of the moisture damaged
balsa wood core areas, breaking down any detected rotted blocks of
moisture damaged balsa wood within the detected moisture damaged
balsa wood core area into wood chips and debris; g) de-coring said
detected moisture damaged balsa wood core areas, by breaking down
said damaged balsa wood core and removing said wood chips and
debris from the detected moisture damaged balsa wood core areas
through said at least one small hole, thereby forming a cavity
within each detected moisture damaged balsa wood core area and, h)
filling each said cavity with a filled epoxy.
2. The method of treating a boat hull as in claim 1, further
comprising the step of removing any hardware from said moisture
damaged balsa wood core areas of the hull, and reapplying and
resealing said hardware after each said cavity is filled with
epoxy.
3. A method of treating a boat hull according to claim 2, wherein
said detected moisture damaged balsa wood core areas are detected
by utilizing a moisture meter.
4. A method of treating a boat hull according to claim 3, wherein
detecting said detected moisture damaged balsa wood core areas
comprises utilizing a thermal camera.
5. A method of treating a boat hull according to claim 4, wherein
detecting said detected moisture damaged balsa wood core areas of
the boat hull further comprises placing a graphical grid on the
boat to clearly identify said detected moisture damaged balsa wood
core areas in identifiable grid squares.
6. A method of treating a boat hull according to claim 5, wherein
detecting said detected moisture damaged balsa wood core areas of
the boat further comprises recording the date and amount of
moisture in each grid square.
7. A method of treating a boat hull according to claim 1, in which
said de-coring of debris comprises routing and turning rotted balsa
wood blocks in each cavity into wood chips and debris using a
rotary cutting tool entering said cavity through a minimally
invasive hole for convenient removal.
8. A method of treating a boat hull according to claim 7 in which
the wood chips and debris are removed from said cavity using a
vacuum hose connected to said hole.
9. A method of treating a boat hull according to claim 8 in which
compressed air is pumped into the troubled areas between said inner
and outer skins to aid in drying the troubled areas.
10. A method of treating a boat hull according to claim 1, wherein
said drying step further comprises applying heat.
11. A method of treating a boat hull according to claim 1, wherein
said drying step further comprises vacuuming.
12. A method of treating a boat hull wherein said drying step
includes applying heat and vacuuming.
13. A method of treating a boat hull according to claim 1, further
comprising blowing the particles out from the boat through said
respective holes of said areas of removed hardware.
14. A method of treating a boat hull according to claim 11, further
comprising the step of inducing pressurized air into respective
spaces between said inner and outer skins of the boat.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
13/723,044, filed Dec. 20, 2012, which '044 application is a
continuation of application Ser. No. 11/890,270, filed Aug. 4,
2007, now abandoned, which '270 application is a continuation of
application Ser. No. 10/857,834, filed Jun. 2, 2004, now U.S. Pat.
No. 7,252,727 dated Aug. 7, 2007 and claims priority under 35
U.S.C. 120 from these applications. These applications are
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to prevention of water damage
to balsa wood cores of fiberglass boat hulls.
BACKGROUND OF THE INVENTION
[0003] Fiberglass boats are typically constructed using an inner
and outer fiberglass skin separated by a balsa wood core. The balsa
wood core is in the form of small separate blocks preattached to a
fabric or fabric like material mesh on one side only. This allows
the separate blocks to tilt in two directions relative to each
other to readily follow the convex contours of a boat. The spaces
between the separate blocks are called veins.
[0004] While the balsa wood is very light weight and offers
adequate crush resistance (on end grain), it is quite vulnerable to
water infiltration between the fiberglass skins of a boat which in
time may cause the core to decay and then eventually to rot.
Typically when this happens, the boat owner puts off repair until
the damage is extensive or structural integrity is compromised
since the current method of repair is drastic. This expensive
procedure involves de-skinning of entire outer fiberglass covering,
replacement of the damaged balsa core, and then replacement of the
outer skin. This entails hundreds of person-hours of effort and can
take a boat out of service for an entire season.
[0005] Examination of the prior art reveals several patents related
to localized repair of non-metallic structures or objects. U.S.
Pat. No. 2,307,958 of Hellier relates to a method of repairing
rubber vehicle tires by using air pressure to locate and dry ply
separations, by injecting the dry air through a hole with a hollow
needle. A cement is then injected to reattach the separated
plies.
[0006] U.S. Pat. No. 4,236,951 of Krchma et al. relates to a method
of treating blisters in asphaltic membrane covered roofs. A
selected liquid hydrocarbon miscible with the asphalt of the
membrane is introduced through a flexible hose with a puncture
output nozzle, and the liquid hydrocarbon is used to heal the
localized blistering of the asphalt.
[0007] U.S. Pat. No. 4,260,439 of Speer is related to an apparatus
and method of plastic repair such as of vinyl seat covers. It
involves the use of a tool with a narrow jet of heated air to cure
a heat curable repair compound.
[0008] Clearly these patents do not teach techniques which can be
applied to the repair of fiberglass boat hulls. However, U.S. Pat.
No. 5,622,661 of Cederstrom is a method of localized repair of
surface blisters of laminated plastic objects including fiberglass
boat hulls. Cederstrom '661 is primarily involved with osmosis type
damage to the exterior boat hull skin.
[0009] Using a combination of controlled heat or cooling with
mechanical action of a strong compressed air jet, in Cederstrom
'661 the damaged area is cleaned and dried in a single operation
using a HYAB-osmosis tool. Damaged material below the skin is not
removed; instead it is reinforced with a penetrating epoxy.
[0010] A similar system is noted in the website of Star
Distributing Corporation of Mystic CT in their excerpt entitled
"Cost Effective Restoration of Decay in Wooden Core Fiberglass
Boats.COPYRGT.". Star Distributing describes a time-consuming
method for repairing wood damaged boat hulls by tapping the boat
with a mallet to estimate wood damaged areas by listening for
hollow echo sounds, drilling holes in those estimated areas,
letting the wood damaged areas dry by ambient air and heat, and
then pouring Clear Penetrating Epoxy Sealer (CPES) into the
estimated damaged portions of a hull. The method of Star
Distributing does not physically remove damaged core; it just
treats it with poured CPES. The method of Star Distributing dries
out areas with rudimentary ventilation and heat, but not with a
system of vacuum plates and sources to facilitate controlled drying
and removal of moisture. The only mention of vacuuming in Star
Distributing is to a usual domestic vacuum cleaner, but Star
Distributing uses a vacuum to remove drill waste, airborne
fiberglass particles and water leaking from the lowest drilled
hole.
[0011] In addition, the method of Star Distributing does not
physically remove damaged wood core areas; it only treats
drill-exposed areas with poured-in CMES, leaving unexposed, damaged
wood core areas which may not be in contact with the CPES, and
which may cause further wood rot damage in the future.
[0012] Initially, tapping the surface is used by both Star
Distributing and optionally by the present invention. But the
present invention goes much further. After initial tapping, then
the present invention uses the moisture meter/infrared camera,
which can accurately predict not just hollow areas, but non-hollow,
moisture-ridden areas. The present invention uses an analytical
grid pattern, dries wood-infested areas with heat and vacuum, then
re-tests the dried areas with the moisture meter/infrared camera,
after using the vacuum plate sub-system.
[0013] Star Distributing does not remove damaged areas; it only
treats them with CMES. In contrast, the present invention uses
augers and bits to remove out rotted core; Star Distributing only
dries it.
[0014] The present invention uses moisture meters to locate water.
The present invention uses grids to make moisture location more
accurately, and to take notes for future moisture testing. But Star
Distributing just pokes holes to examine wood thereat.
[0015] If there is water present, Star Distributing uses a vacuum
cleaner to remove water at lowest point. The present invention uses
vacuum to pull in air from upper holes and leaves it on for days,
to facilitate drying. The present invention's continuous vacuuming
facilitates fast drying of the core. Star Distributing dries by
allowing approximately 1 week drying. But the present invention
uses multiple measuring and monitoring with moisture meters and
similar devices to ascertain proper drying.
[0016] Both Star Distributing's and the present invention's
techniques are minimally invasive. But the present invention
removes rotted sections of wood core and dries out non-rotted wet
areas. Unlike Star Distributing, the present invention uses
flexible cable tools and bits to remove rotted wood. The present
invention preferably uses chopped fiberglass and epoxy to replace
wood core. Star Distributing physically fills bare areas where the
present invention removes rotted wood. But Star Distributing, after
drying the wood core (whether bad or good) doesn't teach removing
wood rot. Additionally, Star Distributing relies heavily by using
the mallet tapping to locate holes representing separation of wood
from fiberglass (de-lamination). Such a reliance does not rise to
the level of sophistication of the present invention, which can
detect moisture infested areas even if there is no separation of
the fiberglass skin from the adjacent water infested wood core
areas.
[0017] After drying by ambient air over time (one week), Star
Distributing uses liquid CPES that is soaked up by wood that takes
a long time to dry. After ambient drying, Star Distributing adds
another CPES in-filling. The CPES coat is poured in to replace wood
lignum lost to bacterial consumption. In contrast, the present
invention is removing and replacing the damaged wood.
[0018] Unlike Star Distributing, the present invention also has
optional preventive maintenance Star Distributing does not remove
damaged wood, but fills drilled plug holes with Fill It and Layup
and Laminating Epoxy (LLE). Star Distributing's main emphasis is
use of poring in CPES to the damaged wood.
[0019] Clearly, the repair methods of Cederstrom '661 and Star
Distributing are different from the present invention. Cederstrom
'661 and Star Distributing do not extend the method to a systematic
analysis of a fiberglass boat hull having a balsa wood core, by
using moisture meter techniques to locate damaged areas not visible
to the tapping or to the naked eye, and to heat and remove the
damaged wood core with accurately measured minimal incisions of the
fiberglass boat outer skin.
[0020] The invention of U.S. Pat. No. 5,277,143 of Franguela, Ship
Hull Repair Apparatus, describes a device that can be rapidly
deployed to repair a breach in the hull of a boat. It acts to plug
the hole in the hull and is designed to be installed by a diver
from the exterior in an emergency to stem the flow of water into
the boat if the breach is below the water line. This apparatus will
seal a hole in the hull of any type of construction (eg.--metal,
fiberglass, wood) as long as it is sized to be compatible with the
damage.
[0021] FIG. 1 of Franguela '143 shows the method of installation by
a diver. FIG. 1A of Franguela '143 shows a perspective view of the
apparatus showing the mounting plate (sealing disk) 15 with two
pneumatic storage cylinders 39 and 40 which contain compressed air
or other gas to operate the apparatus. The crossectional side view
of FIG. 4 permits one to quickly grasp the operational features of
the apparatus. In this view, the configuration is as stored and
prior to installation. It will be appreciated that four legs (see
FIG. 2) 20 through 23 would be pushed through the hull breach
protruding into the inside of the boat hull. Pneumatic piston 34
within cylinder 16 is poised to pull on cables 37 which will pivot
legs 20 through 23 into the configuration shown in FIG. 7 upon
pressure released from pneumatic storage cylinder 44. This action
locks the apparatus to the side of the hull aided by distal hooks
such as 27 and 28. At this time, compressed gas is released from
cylinder 39 to inflate annular sealing bladder 38 to form a water
tight seal against the boat hull.
[0022] Although the repair is complete, there will be some
hydrodynamic drag from the apparatus extending somewhat from the
hull surface if below the water line. If above the water line or
close to it, the repair also imposed aesthetic problems. Also, the
repair may lose viability after long term use due to possible
permeation of compressed gas through the flexible sealing bladder.
For these reasons, the invention of Franguela '143 is considered to
be an emergency and temporary repair apparatus.
[0023] In contrast to Franguela '143, the present invention is a
repair system and method for fiberglass boats. The present
invention is a system for locating core damage in fiberglass boat
hulls while in dry dock, removing damaged wood core and repairing
water intrusion damage to the damaged wood core areas. Further,
drying apparatus involving the use of vacuum pumps and heaters are
used to prepare the damaged areas for permanent repair. The method
of the present invention is not designed to repair a hull breach
which transverses both the outer and inner skins of a fiberglass
boat, nor is the repair method applicable to wood or metal hull
construction. Both the method and apparatus of the present
invention bear no relation to the repair apparatus of Franguela
'143.
OBJECTS OF THE INVENTION
[0024] It is therefore an object of the present invention to
provide a system and method for repair of water damaged balsa wood
cores within fiberglass boat hulls.
[0025] It is also an object of the present invention to provide for
such a system, which minimizes surgical incision, and wholesale
removal of large sections of the outer fiberglass skin of a boat
hull.
[0026] Other objects will become apparent from the following
description of the present invention.
SUMMARY OF THE INVENTION
[0027] In keeping with these objects and others, which may become
apparent the system and method of the present invention replaces
only those sections of rotted balsa core of a boat hull as needed
while minimizing the damage to the outer fiberglass skin. In early
stages of moisture attack, only sporadic regions and spots on the
boat are damaged. The boat hull repair method of the present
invention locates the damaged areas, dries out the damaged areas,
repairs the damaged core, and prevents further damage by closing
any leaks in the boat hull skins.
[0028] Early attention to these areas using methods of this
invention greatly limits the labor content of the repair. Then, as
part of the repair, analysis of the moisture entry paths and their
repair would prevent further deterioration. The rotted balsa is
removed by using rotary cutting tools, and alternatively the chips
can be vacuumed out. A preferred embodiment entails the chips,
foreign matter, or sediment to be blown out of the boat hull with a
tool such as an air chuck or the like. The access to the bad areas
is through relatively small holes in the outer fiberglass skin. The
cavities thus formed are not refilled by balsa; instead a filled
epoxy is used.
[0029] Suspected rotted areas are initially spotted by visual
inspection, sounding, and "tug" tests. At this point, a moisture
meter is used to verify the presence of water-saturated or moist
wood; this is done through the outer skin. It is not a highly
invasive procedure.
[0030] Once a region is identified as having water infiltration, a
grid pattern is drawn on the outer fiberglass. A few core samples
are taken with a hole saw. Rectangular openings below areas of wet
core or wood are cut in the outer skin. Gasketed vacuum plates are
attached to the side over these openings and a vacuum pump is
attached using a manifold. Now a systematic moisture map of each
grid location is made whereby the moisture content of the core is
recorded along with the date. More core samples are taken where
indicated by moisture readings.
[0031] As time goes on, moisture readings will decrease as the
vacuum draws in heated dry air. Dry heated air under pressure can
also be forced in above the wet core or wood regions. When the
moisture reading is very dry (about 5%) the repair of the rotted
areas can start.
[0032] Using commonly available tools and equipment, the wet core
or wood areas of balsa are removed through small openings in the
fiberglass shell. Both pneumatic and electrically driven hand tools
can be used. Typically, straight and right-angle grinder drivers
are used with butterfly cutters, de-burring bits, and other types
of de-veining tool bits. Using a drive motor with a tool at the end
of a flexible shaft enables one to reach wet core or wood areas far
from the edge of a core hole. Thus deep cavities can be made with
minimal exterior damage. Wood chips and debris are usually removed
by using a tool such as an air chuck or a powerful vacuum at the
end of a hose attached to a commercial vacuum cleaner,
alternatively any tool which can accomplish the same purpose
commonly known to persons skilled in the art may be utilized.
[0033] However, the vacuum system attached to the vacuum plates is
only used for the drying process. Large attached sections of
damaged core are physically removed using a routing procedure with
rotary tools and bits. Debris and smaller particles are vacuumed
out using a vacuum cleaner.
[0034] Once the cavities are made, and after drying, epoxy is mixed
with chopped glass mill fiber and the mixture is applied to fill
the cavities using a manual or pneumatically driven caulking gun.
The skin repair is made by sanding the repair flush with the outer
boat contour, applying a seal coat, a gel coat and finally a
barrier water proofing.
[0035] Instead of taking three months to cut open large sections of
a boat hull, the selective incisions and treatment of a core
damaged boat hull can be done in less than three weeks duration,
with significant labor and material savings.
[0036] Therefore, the present invention provides a method for boat
repair, which includes detecting troubled areas of the boat, such
as water infested wood core areas. The repair procedure further
includes boring relatively small cavities within the boat in
relation to the troubled areas. Heat is applied to the troubled
areas and water damaged particles are blown out and/or vacuumed
from the boat through the holes.
[0037] Detecting troubled areas is accomplished by utilizing a
moisture meter or a heat sensing thermal or infra-red camera to
detect the presence of moisture damaged wood core between the inner
and outer skins of the boat, or beneath the deck or roof areas of
the boat.
[0038] Once the moisture-ridden areas are located, areas of the
boat are in a grid marked to clearly identify the troubled areas.
Typical markings associated with the grid include recording the
date and amount of moisture in each grid square if deemed
necessary.
[0039] Additionally, the method for boat hull repair includes a
search in finding the trough of the boat where water
accumulates.
[0040] Once the areas are identified, the holes are drilled, at
suspected damaged areas, and an auger removes particles from within
the boat.
[0041] While straight augers can be used near the drilled holes for
relatively inaccessible areas away from the drilled hole, a
flexible auger removes particles from within the boat.
[0042] An auger can also be utilized to aid in facilitating the
airflow within the boat.
[0043] As part of the repair process, heat is applied with a
heater, such as a gas driven heater, an electric heater, an
infrared heater, a convection heater or by placing the boat within
a temperature control room. The heat dries out the moisture,
allowing the water damaged particles to be removed and replaced.
Heat may be selectively applied to damaged areas, or to the entire
boat.
METHOD OF OPERATION
[0044] The methods of this invention are intended to identify and
repair all wet core hull areas and to perform preventive
maintenance on dry hull areas to restore the integrity of a
fiberglass boat hull and to prevent new water infiltration damage
beyond the level of a new hull.
[0045] The wet area repair guidelines using a surface moisture
meter such as a model GRP33 use the following criteria. Any balsa
cored area reading 15% or above is considered a wet area. Any wood
cored area reading 20% or above is considered a wet area. In
addition, any balsa/wood cored area with a relative difference of
5% or more than the average moisture reading of the surrounding
area is considered wet and must be repaired.
[0046] An overview of the repair steps involves removing all
through-hull fittings or hardware. Wet core areas are then dried
out using heat lamps, lights or heaters, hot-vac systems, or
octopus vacuum with grid system. If necessary, any area not drying
out is de-cored and repaired accordingly. After repairs are
finished, all through-hull fillings or hardware is reinstalled
using new sealant. The recommended sealants are 3m 4200 Marine
Grade Sealant/Adhesive for both below the waterline and above the
waterline.
[0047] The preferred methods of repair are well described in the
above sections of the invention relating to a minimally invasive
procedure requiring the drying out of wet core areas. These methods
offer great benefits in reduced labor costs; they are described in
the text above and FIGS. 1 through 9A. In cases where the core is
not responding to drying attempts, the areas are de-cored. This can
be accomplished either from the interior, as detailed in the
discussion of FIG. 11, or from the exterior in a similar procedure.
If performed from the interior, clear access must be provided to
the repair area. All equipment, sole plates, insulation, and all
other items that may prevent clear access must be removed prior to
the repair.
[0048] Obviously, all removed items must be replaced after the
repair. If the de-coring is performed from the exterior of the
hull, access is more easy. The procedure is similar to that in FIG.
11, but it is the outer laminate instead of the inner laminate that
is penetrated. Also, It is the schedule and finish of the outer
laminate that must be matched in the final steps.
[0049] The general preventive maintenance guidelines call for three
different approaches applicable to three different regions of a
hull. First, all dry areas below the waterline are to be
disassembled, de-cored and reassembled with new sealant. The steps
in this procedure are detailed in the discussion of FIG. 12.
Secondly, all dry areas above the waterline will be cleaned of all
old sealant around the outside edge of the hardware; then the
hardware is resealed from the exterior with a new bead of sealant.
Third, all gunnel/stainless is removed and inspected. The steps for
preventive maintenance of this region are described in the text for
the maintenance chart of FIG. 10B.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The present invention can best be understood in connection
with the accompanying drawings. It is noted that the invention is
not limited to the precise embodiments shown in drawings, in
which:
[0051] FIG. 1 is a perspective view of a prior art boat hull repair
method, wherein a portion of boat hull with a major part of the
fiberglass skin is peeled away, revealing the damaged areas of the
core;
[0052] FIG. 1A is a perspective view of a moisture meter used in
diagnosing a moisture damaged core of a fiberglass boat hull
requiring treatment according to the system and method of the
present invention;
[0053] FIG. 1B is a perspective view of a collection of fabric
backed balsa wood core blocks inside a boat hull, shown with the
outer fiberglass skin layer removed;
[0054] FIG. 2 is a front elevational view of a portion of a boat
hull being treated in accordance with the system and method of the
present invention;
[0055] FIGS. 2A and 2B are side elevational views of grid systems
shown depicted upon respective left and right sides of a boat hull,
showing sources of water intrusion, such as port hole windows and
motor vent holes;
[0056] FIG. 3 is a close-up perspective detail view of a vacuum
draw plate used in connection with vacuum cleaning of moisture and
damaged wood core debris of a boat hull being treated in accordance
with the system and method of the present invention;
[0057] FIG. 4 is a close-up perspective view of the vacuum system
of the present invention;
[0058] FIG. 4A is a perspective view of the vacuum and pressure
systems shown in place at a boat hull to be repaired;
[0059] FIG. 5 is a close-up detail view of saw equipment used for
introducing incision holes of the system and method of the present
invention;
[0060] FIG. 6 is a perspective view of a straight oriented
hand-held drilling and routing tool of the system and method of the
present invention;
[0061] FIG. 7 is a is a perspective view of a bent, right angle
oriented hand-held drilling and routing tool of the system and
method of the present invention;
[0062] FIG. 8 is a is a perspective view of a flexible oriented
hand-held drilling and routing tool of the system and method of the
present invention;
[0063] FIG. 9 is a close-up elevational view of a portion of a boat
hull being treated in accordance with the system and method of the
present invention;
[0064] FIG. 9A is a close-up elevational view of a flexible auger
used on a portion of a boat hull being treated with the system and
method of the present invention;
[0065] FIG. 10A is a chart showing the relation between the
different repair techniques of this invention for repair of wet
core damaged areas in fiberglass boat hulls;
[0066] FIG. 10B is a chart showing the preventive maintenance
techniques of this invention for different areas of a fiberglass
boat hull. FIGS. 10A and 10B together constitute a combined chart
entitled, "Repair and Maintenance for Fiberglass Hulls";
[0067] FIG. 11 is a cutaway side view, taken as shown in the dashed
line ellipse "11" shown in FIG. 9, showing a damaged area of the
hull with a wet core section, further showing the outer skin
removed and showing various layers progressively downward and
inward through the hull with a section of the inner laminate (skin)
removed and the wet core area cut out with a bevel to effect a
de-core procedure from the interior of the boat; and,
[0068] FIG. 12 is a close-up exploded view 12 of a hull detail with
through-hull hardware shown as being just removed for preventive
maintenance below the waterline taken as shown in the dashed line
ellipse designated as "12" in the region of the porthole shown at
the front end of boat hull 2 shown in FIG. 9.
DETAILED DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 illustrates a prior art method of boat repair which
involves peeling back of the fiberglass skin to locate and repair
the damaged areas. Boat hull 1 is shown with part of the fiberglass
skin peeled back 3 from its normal attached position 2 to reveal
damaged areas 5 in the exposed balsa block core 4. This analogous
to "major surgery" as compared with the "laparascopic surgery"
approach of this invention.
[0070] FIG. 1A shows an analog moisture meter 8. Digital meters as
well as moisture probes attached to PDA's or laptop computers are
also available. Infrared cameras, or other remote moisture
detectors, may also be used for thermal imaging of moisture
presence.
[0071] FIG. 1B is a hull detail showing compound curve contour 20,
balsa blocks 23, mesh 22 to which blocks 23 are preattached, and
the inner fiberglass to which mesh 22 is loosely attached. Note
that blocks 23 can adjust to hull contour 20; in so doing spaces or
veins 24 are formed between the balsa blocks. These veins 24 often
act as conduits for infiltrated water which is then conducted to
damage larger regions.
[0072] FIG. 2 is an exterior hull section 1 with skin intact. Grid
region 10 is drawn on the surface for a systematic moisture survey
of the surface to locate damaged areas. Vacuum plates 14 are
attached over openings in the hull to extract moisture from damaged
areas via vacuum hoses 11. Tape 12 is used to attach plates 14 to
the hull.
[0073] FIGS. 2A and 2B show two different sides of boat 1 hull
respectively. They show the location of port hole windows 6 and
motor vents 7.
[0074] FIG. 3 is a close-up of vacuum plate 14. It preferably
includes a preferably transparent plate 30 such as of
polycarbonate, gasket 31, such as of a flexible sealing material
such as closed cell foam, which forms an airtight seal against the
hull, and hose barb 32 for attachment to vacuum hose.
[0075] FIG. 4 shows a stand-alone vacuum system 35. Commercial
vacuum pump 36 is attached via large vacuum hose 37 to vacuum
manifold 38. Vacuum gauge 39 indicates vacuum. A number of hose
barbs 42 are used for attachment of vacuum hoses 11. Those barbs 42
not used are capped by seal caps 41 to prevent vacuum leakage.
[0076] FIG. 4A shows a combined vacuum and pressure center 45.
Vacuum pump 36 is powered by motor 46 which is plugged into outlet
53. Intake line 48 from manifold to vacuum pump attaches to vacuum
manifold 38; drain spigot 47 is to drain out accumulated water from
the air drawn in by vacuum pump 36. Vacuum hoses 11 are attached to
vacuum plates 14. The pressure supply side obtains compressed air
from an external source via compressed air line 56 which is
attached to air inlet filter 49 on air tank 50. Electric heater 54
attached to outlet 53 heats the compressed air in tank 50 before it
is distributed via compressed air manifold 55 and hoses 51 to line
filters 52. These lead to input openings in the fiberglass hull
skin to aid in drying damaged areas. Compressed air gauge 40
indicates pressure at manifold 55.
[0077] FIG. 5 shows hole saw equipment including electric drill
driver 60, mandrel 61, and two sizes of hole saw 62. A cordless
version can be used as well.
[0078] FIG. 6 shows a straight pneumatic tool 66 powered by
compressed air hose 68 with control valve 67 and veining bit
69.
[0079] FIG. 7 shows right angle pneumatic driver 72 with control
valve 73, chuck 74 and butterfly bit 75.
[0080] A flexible shaft driver 78 with flexible shaft 79,
guidepiece 82, collet 81 and deburring tool 80 is shown in FIG. 8.
It can be electrically or pneumatically driven.
[0081] A section of attached fiberglass skin 2 is shown in FIG. 9.
It has core access hole 85 which enabled the removal of damaged
core region 86.
[0082] FIG. 9A illustrates the use of a modified flexible shaft
auger 90 in removing damaged core creating cavity 98 through access
hole 85. Here adjustable stand 94 with hook 93 supports motor 91
via hanger loop 92. Flexible shaft 95 feeds through a bendable
semi-rigid outer covering 96 (like that of a gooseneck lamp) to
emerge at guidepiece 82. Collet 81 retains cutting tool bit 80. The
modification is the addition of sleeve 96 which permits tool 80 to
be oriented in any direction to gouge out cavity 98.
[0083] The repair and maintenance charts of FIGS. 10A and 10B
illustrate the relationships between the different techniques of
this invention in renewing the integrity of fiberglass boat hulls.
In the repair chart of FIG. 10A, the first step is to locate the
wet core areas as discussed above with the use of a moisture meter
and possibly drawing a grid system on the exterior hull surface for
accurate data collection of moisture content over time. While the
preferred method of repair is the minimally invasive method
discussed above (shown as the leftmost branch), in some cases,
stubborn wet areas are found which do not respond to the drying
techniques already discussed in detail. In these cases, either the
inner or outer laminates or skins are actually removed over the
entire wet area. This can be done from the interior whereby no
repair is required on the highly visible exterior surface. In some
cases, the wet area cannot be reached from the interior and the
repair must be made from the exterior surface. This method of
repair is called de-coring whereby the wet core section is actually
cut out. Then, new core material is added, and the repair area is
finished to blend in with the rest of the inner or outer laminate
in the vicinity. This process is commonly done when the core is
rotted. Alternatively, the outer skin is surgically cut in the
vicinity of the water damage to facilitate drying of the cores
which have no rot.
[0084] The dry areas of the hull are treated to three basically
different preventive maintenance techniques as described by chart
10B. Above the waterline, old sealant is cleaned or removed from
around any hardware. Then a bead of new sealant is used to seal the
exterior of the hardware.
[0085] All gunnel/stainless is removed and inspected. All broken or
bent screws are removed, and misdrilled holes or deck-to-hull seams
are repaired and/or sealed with sealant. The gunnel/stainless is
then reinstalled with a new bead of sealant. Finally, drain holes
are drilled in the gunnel molding on the underpart.
[0086] Below the waterline, all through-hull hardware is removed.
Core material is carefully removed to a predetermined depth such
as, between one to two inches from the edge of the cutout. The
de-cored areas are then filled with epoxy before the hardware is
reinstalled with new sealant.
[0087] FIG. 11 is a side cutaway view, taken as shown in the dashed
line ellipse "11" shown in FIG. 9, of an example of a wet area
repair from the interior of the hull, illustrating the progressive
steps encountered in the repair. In the cutaway view of FIG. 11,
the uppermost item shown is the vacuum suction cup 138, which is
placed above and having a connection through plastic bag 137, under
which is bleeder fabric layer 136, then strip ply/peel layer 134
and the lowest layer, which is fiberglass level 121. FIG. 11 also
shows the affected region after inner laminate 122 is ground back
until all damaged areas are removed Inner laminate 122 is tapered
back at region 128 to a suitable taper, such as, for example, a
20:1 taper ratio and the wet core is removed with a tool, such as a
sharp bevel. This area is further prepared by grinding or filling
any voids with a filler, such as, for example, polyester putty. All
dust and loose debris is blown out and/or vacuumed out of the area
to be laminated. The next step is to apply the first layer of
fiberglass. This involves solvent-wiping the prepared laminate area
and then applying, for example, 2 oz/sq.ft. chopped strand mat
(CSM) or other suitable material, to the repair area with a
appropriate overlap, such as a two inch overlap, at the perimeter.
This new laminate layer is then allowed to cure. The opposite skin
and laminated perimeter 130 is prepared for replacement of the core
by grinding to a near white condition and insuring the overlaps are
smooth. The next step is to prep the new core. The new core is
pattern cut and pre-fit to the repair area. The edges are machined
to closely fit the beveled perimeter. All dust and foreign debris
is again blown out and/or vacuumed out from the repair area. The
next step is bedding of the new core material. Bagging of the core
involves first placing a seal, such as tacky tape, around the
perimeter of the prep area. The bedded surface of the balsa core is
then primed with a primer, such as, for example, catalyzed V/E
resin, before bedding. Next, using the V/E resin, chopped strand
mat material, such as at least 2 oz/sq.ft. of the chopped strand
mat (CSM) materials, are applied and catalyzed. Vacuum bag 137 is
carefully sealed around the periphery using a seal, such as for
example, tacky tape 132. Vacuum is then applied through vacuum port
suction cup 138. After cure, bag 137 is removed. The core is ground
and detailed, cleaned, and then primed with catalyzed resin. When
resin is cured, any voids are filled with a filler, such as for
example, polyester putty. All excess putty or resin/fiberglass are
cleaned from the core. Repair area is then prepared for the
replacement laminate by grinding the perimeter to a near white
condition. The core is feather ground to eliminate any excess
portion of excess putty. The area to be laminated is again vacuumed
and cleaned. The final step is the step of installing the new
surface laminate. The repair area to be laminated is solvent wiped,
and then the original inside laminate schedule is applied. This
involves installing the first laminate ply to overlap the existing
laminate by an appropriate dimension, such as, for example, a
minimum of two inches. Each successive ply should overlap the
previous by a minimum dimension, such as, for example, of one inch.
After curing, a light grinding of between each set of laminates is
performed. Finally the exposed surface finish should replicate the
original interior surface and be equal in finish to the existing
production standard.
[0088] FIG. 12 illustrates dry area preventive maintenance
procedures used below the waterline. FIG. 12 is a close-up exploded
detail view of the region surrounding any through-hull hardware
feature, taken as shown in the dashed line ellipse designated as
"12" in the region of the porthole shown at the front end of boat
hull 2 shown in FIG. 9. In FIG. 12, removed hardware 150 is shown
removed from the porthole. Outer fiberglass laminate 121, dry
undamaged core 123 and inner laminate 122 are shown. The next step
of the procedure includes the step where one appropriate sections
151, such as for example, one inch deep sections, of core 123 are
removed from between laminates 121 and 122. After the cutout is
cleaned out, de-cored regions 151 are filled with an epoxy 155,
such as, for example, West Systems Marine Epoxy. After epoxy 155 is
set, it is sanded smooth. Then the true-hull hardware 150 is
reinstalled with new sealant, such as for example, as 3M 5200
Marine Grade Sealant/Adhesive.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0089] The present invention has broad applications to many
technical fields for a variety of articles. For illustrative
purposes only, a preferred mode for carrying out the invention is
described herein, wherein a repair system for treating boat hulls
with rotted balsa wood cores utilizes a minimally invasive incision
and treatment technique of the fiberglass boat hull.
[0090] As shown in FIG. 1, in a prior art boat hull repair method,
a major portion of boat hull 1 with a large part of the fiberglass
skin 3 is peeled away from fiberglass skin 2, revealing the damaged
areas 5 of the balsa wood core of hull portion 4 to be treated and
removed.
[0091] In contrast, in the present invention, general areas 5 of
moisture damage to a boat hull 1 are determined by exposing the
exterior surface of a boat hull 1 to a moisture detector 8, such as
a moisture meter as shown in FIG. 1A, or by other moisture sensing
equipment, such as a thermal or infra-red camera. A typical
moisture meter 8 has either a digital or analog output, showing
moisture readings of from zero to about thirty percent moisture
content on a relative scale extending from a very dry condition to
a most condition and finally to a wet condition.
[0092] FIG. 1B shows a collection of fabric backed balsa wood core
blocks 23 inside a boat hull 1, shown with the outer fiberglass
skin layer removed. The balsa wood blocks are shown slightly
fanning outward along a rear curved inner fiberglass reinforced
fabric mesh backing 22 attached to an inner fiberglass skin 21,
following a curve contour 20 of the boat hull 1. The triangular
area gaps located between adjacent balsa wood blocks 23 are defined
as veins 24, through which water intrusions flow, thereby damaging
adjacent balsa wood blocks 23. When water intrudes into the area
between the inner fiberglass layer 21 and outer fiberglass boat
hull skin layer 3, these balsa wood blocks 23 are susceptible to
moisture damage and rot, thereby interfering with the structural
integrity of the inner buoyant core of the boat hull 1.
[0093] As shown in FIGS. 2 and 9, the boat hull repair system and
method of the present invention removes the aforementioned moisture
and water damaged wood core from within the fiberglass skin layers
3 and 21 of a boat hull 1.
[0094] FIGS. 1 and 2 show a front view of a side of a boat hull 1,
typically comprising an exterior fiberglass skin 3 and an interior
fiberglass skin layer 21 shown in FIG. 1B, both separated by a core
of a plurality of small, flat edged balsa wood core blocks 23
connected by a flexible fiberglass reinforced textile mesh strips
22, as shown in FIG. 1B, which allows the incremental placement of
the individual, generally linear based, blocks 23 over one or more
complex curves 20 of the boat hull. Typically the blocks 23 are one
to two inches in length, with thickness' varying in a range of from
about one quarter (1/4) inch in thickness to about three quarters
(3/4) inch in thickness. Often the balsa wood blocks 23 are either
three eighth (3/8) inch to about one half (1/2) inch in
thickness.
[0095] Although the blocks 23 are positioned adjacent to each
other, as shown in FIG. 1B, they are spaced apart from each other
by a small distance, to allow the incremental bending of the strip
of flat blocks 23 over a complex curve contour 20 of the boat hull
1. However, these spaces, referred to in the maritime trade as
"veins" 24 are vulnerable to exposure to water running
therethrough, from cracks or damaged seals in the boat hull 1 or
its accessory structures, such as port holes, gunnel molding, weep
holes in the anchor area or ventilation holes. Other areas of water
intrusion include the motor compartments of the boat. Water further
collects in the trough areas of the boat hull 1, where the complex
curves 20 are of such configuration that they cannot be filled by
balsa wood blocks 23.
[0096] The balsa wood cores shown in FIG. 1B before moisture damage
thereto, are susceptible to water induced rot, eventually
pulverizing and leaving areas having a lack of structural integrity
in the areas of damaged and pulverized balsa wood core blocks
23.
[0097] The prior art generally includes macro cutting of large
sections of the damaged balsa wood core areas of blocks 23
underneath the outer fiberglass skin 3 of the boat hull 1, and
surgically removing wholesale sections of balsa wood block
aggregates.
[0098] In contrast, as shown in FIGS. 2 and 9, the present
invention uses selectively placed microsurgical incisions, to make
minor incisions in the outer fiberglass skin 3 of the boat hull 1,
and selectively targeting the moisture ridden areas of the balsa
wood core blocks 23 shown in FIG. 1B before moisture damage thereto
between the inner and outer fiberglass layers 3 and 21 of the boat
hull 1.
[0099] First, the boat hull 1 is examined with moisture meters 8,
shown in FIG. 1A, to ascertain the general area of moisture
infestation before any cuts are made into the outer boat hull skin
3. Thermal imaging cameras can also be used.
[0100] Then, as shown in FIG. 2, a grid region 10 is laid out over
the general areas of moisture infestation, and selective cuts are
made to identify the exact locations of the moisture ridden core
areas of balsa core blocks 23. As shown in FIG. 5, holes may be
cut, for example, by a hand-held hole drill 60 having a mandrel 61
holding cylindrical serrated, barbed hole saws 62. Typically the
grid region 10 is graphed out by using a grease pencil or other
marker and a straight edge, such as a ruler or yardstick.
Additionally, the grid pattern can be implemented by optical
projections or other similar temporary marking means. The grid
region 10 is broken down into discernable sections, labeled by
section labels, such as, for example, "A", "B", "C", etc.
[0101] Normally the grid region 10 shown in FIG. 2 is not marked
all the way up to the top of the boat hull 1, because the top
portion of a boat hull 1 is normally not infested with water
permeation.
[0102] The grid region 10 is dated at locations of significant
moisture readings every two or three days during treatment.
Moisture readings are repeated during treatment, to ascertain
whether moisture content has decreased from wet readings of between
twenty and thirty percent concentration, to a relatively dry
concentration of less than ten percent moisture content, during
treatment of the boat hull 1 with the heating and vacuum system and
method of the present invention, whereby vacuum plates 14 are
attached with fastening means, such as tape 12, over openings in
the hull 1 to extract moisture from damaged areas via vacuum hoses
11. As shown in FIG. 3, vacuum plates 14 include transparent plate
portion 30, such as of polycarbonate, and at least one vacuum hose
barb 32, to which is attached a respective vacuum hose 11 shown in
FIG. 2. An elastomeric seal 31, such as a closed cell foam gasket,
seals vacuum plate 14 upon boat hull 1.
[0103] Stand-alone vacuum system 35, shown in FIG. 4, includes
vacuum pump 36 having large vacuum hose 37 attached to vacuum
manifold 38, wherein vacuum gauge 39 indicates vacuum. Vacuum
manifold 38 has a plurality of hose barbs 42, to which are attached
vacuum hoses 11. Unused barbs 42 are capped by seal caps 41 to
prevent vacuum leakage through vacuum manifold 38.
[0104] An overall vacuum and pressure center 45 with vacuum pump
36, being powered by motor 46 plugged into outlet 53, is shown in
FIG. 4A. Intake line 48 from manifold to vacuum pump attaches to
vacuum manifold 38 and drain spigot 47 drains out accumulated water
from the air drawn in by vacuum pump 36. At the boat hull 1, vacuum
hoses 11 are attached to vacuum plates 14. The pressure supply side
obtains compressed air from an external source via compressed air
line 56 which is attached to air inlet filter 49 on air tank 50.
Electric heater 54 attached to an electrical power source, such as,
for example, outlet 53, heats the compressed air in tank 50 before
it is distributed via compressed air manifold 55 and hoses 51 to
line filters 52. These lead to input openings in the fiberglass
hull skin, in the regions of vacuum plates 14, to aid in drying
damaged areas. Compressed air gauge 40 indicates pressure at
manifold 55.
[0105] FIG. 9 shows a typical hole 85 cut through an exterior
fiberglass skin of the side of a boat with the hole saw tool shown
in FIG. 5, in the region of a rotted wood core portion 86 of the
wood core 20, shown in FIG. 1B before moisture damage thereto,
beneath the exterior fiberglass skin of the boat hull.
[0106] Core samples are taken through the exterior boat hull
fiberglass skin, in the vicinity of the sawed holes shown in FIG.
9. Visual observations are made to see the condition and color of
the damaged core sample, to ascertain pulverization and/or rotting
of the moisture infested wood blocks, shown in FIG. 1B before
moisture damage thereto.
[0107] As shown in FIGS. 6, 7 and 8, various straight oriented
routing tools (FIG. 6), right angle bent oriented routing tools
(FIG. 7) and flexible multidirectional oriented routing tools (FIG.
8) are used to rout out and remove significant chunks and portions
of water rooted debris from the damaged wood core portions beneath
the exterior fiberglass skin of the boat hull shown in FIGS. 2, 2A,
2B and 9.
[0108] FIG. 9A shows a flexible auger including a motor suspended
by a hook and hanger loop. The motor rotates a cutting tool by
producing power through a flexible shaft, similar to those of tools
of Dremel Corporation. The flexible shaft is guided through a
stiffening sleeve, such as a high durometer elastomeric tubing
slipped at the shaft and handpiece remotely inserted through a hole
to an inaccessible area beneath the boat hull skin. The stiffening
sleeve assists in guiding the normally too flexible shaft. By
adding the stiffening sleeve, the collett holding the cutting tool
can be remotely manipulated in place for cutting. Alternatively, a
bendable outer covering such as used with a gooseneck lamp can be
used over the flexible shaft.
[0109] Heat is applied from propane fired hot air heaters through
small incisions, similar to incisions for applying vacuum
therethrough (as in FIGS. 2, 3 and 4) typically in the top of the
damaged area, to dry out the moisture ridden damaged balsa wood
core areas 86 of the wood core areas 20, shown in FIG. 1A, similar
to the moisture damaged areas 5 of wood core area 4 of prior art
FIG. 1, before moisture damage thereto.
[0110] As also shown in FIG. 2, during the selective boat hull
drying process, vacuum is selectively applied from below, also
through small incisions, to promote drying by facilitating
circulation of air within the boat hull.
[0111] As shown in FIGS. 4 and 4A, vacuum force is selective
applied under sealed vacuum draw plates 14 having a preferably
centrally located vacuum hose barb 32 connectable to a vacuum hose
11 and vacuum power source 36. The vacuum draw plates 14 are
preferably made of transparent but strong materials, such as
polycarbonate, and are sealed at respective edges thereof by a
gasket 31, such as, for example, a closed cell foam gasket.
[0112] As shown in FIGS. 2, 2A, 2B, 4, 4A and 5, vacuum can be
selectively applied in a number of moisture ridden areas by a
plurality of vacuum draw plates 14 attached by respective vacuum
hoses 11 to a vacuum gauge-controlled manifold 38 connected by a
further vacuum hose 48 to a vacuum power source 36, such as a
commercial electrically powered vacuum pump having an AC power plug
and electrical cord.
[0113] While direct cleaning out can be done of the moisture
infested balsa wood core areas 86, with straight or bent
electrically or pneumatically powered routing tools operating
within the boundaries of the incisions, it is alternatively known
that damaged and/or wet balsa wood material can also be removed
remotely from beneath the exterior fiberglass skin of the boat
hull, by using routing tools shown in FIGS. 8 and 9A, having
flexible neck portion conduits 79 or 95 connecting a routing head
to a power supply, wherein the flexible conduits 79 or 95 are used
to direct the location of routing tool heads 80 at selected
locations beneath uncut portions of the exterior fiberglass skin 2
of the boat hull.
[0114] Veining bits are used in straight, angled or flexible necked
routing grinder tools (shown in FIGS. 6, 7, 8 and 9A respectively)
to remove the damaged balsa wood core blocks shown in FIG. 1B
before moisture damage thereto. Butterfly bits and other de-burring
bits are used with drills for de-veining and removing damaged core
areas.
[0115] After the removal of the damaged core, the dry cleaned
cavities are filled and re-packed with a re-sealing epoxy resin
having a high density filler, such as chopped glass mill fibers.
The resin is applied from a dispenser, such as, for example, a
manually operable caulking gun, which injects the epoxy resin into
the cavities. Alternatively, the caulking gun may be powered by an
air pump.
[0116] The treated areas are sealed first with ferring compound,
then a sealant, such as epoxy, vinyl ester, etc., then covered by a
gel coat and finally covered by a waterproof barrier coat such as a
creamy gel coat and color of finish gel coat. This sealing process
is repeated. For cosmetic finishing of the repaired areas, the
areas are wet sanded then treated areas are treated with a surface
finishing compound, and finished by sanding and wax compounding of
the surface, to restore the treated areas to be as smooth and
blemish-free as before treatment.
[0117] As noted herein, preventive steps can also be done in
accordance with the present invention, to prevent water intrusion
and future moisture damage to the boat hull.
[0118] In the foregoing description, certain terms and visual
depictions are used to illustrate the preferred embodiment.
However, no unnecessary limitations are to be construed by the
terms used or illustrations depicted, beyond what is shown in the
prior art, since the terms and illustrations are exemplary only,
and are not meant to limit the scope of the present invention.
[0119] It is further known that other modifications may be made to
the present invention, without departing the scope of the
invention, as noted in the appended Claims.
* * * * *