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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to an improved trim molding.
Interior trim detail, otherwise known as molding, is added in buildings to
improve its decorative appearance. One type of interior trim detail is
decorative crown molding which is secured to the joint interconnecting the
top of a wall and a ceiling. Examples of other types of interior trim
detail are, for example, (1) chair rails which are bands of trim located
approximately four feet high on a wall, (2) capitals which are trim at the
top of a column, (3) pedestals which are trim at the bottom of a column,
and (4) columns which are vertically oriented trim attached to a wall to
provide the appearance of a column. The trim detail may also be used on
the exterior of the building, if desired.
Interior trim detail traditionally is constructed by forming expanded metal
lath or chicken wire into the basic contour of the particular trim. The
metal lath or chicken wire is then attached to the building at the desired
location, such as with the use of nails or screws. Thereafter, wet plaster
material is applied to the metal lath or chicken wire and shaped to the
desired form, generally known as screening the plaster. Unfortunately,
such a process requires skilled artisans to mold an interior trim that is
aesthetically pleasing and uniform along its length. Also, such
construction techniques are labor intensive and thus expensive.
Accordingly, while many construction projects would like to use interior
trim detail, the construction expense is generally prohibitive.
An alternative technique employed to manufacture interior trim detail
involves obtaining sheet metal negatives of the desired exterior trim
contour. In other words, the interior of the metal negative has the
desired exterior shape of the resultant trim. A thin layer of foam coat
material is spread within the metal negative. The foam coat material is a
gypsum-based, glass-fiber reinforced acrylic coating intended to be used
as a foam plastic thermal barrier. Such foam coat is available from
Hamilton Materials, Inc. of Orange, Calif. under the trade name FC-90 Foam
Coat Foam Plastic Protection. A semi-rigid expanded polystyrene foam
plastic material with the same shape as the interior of the metal negative
is pressed into the metal negative. The foam coat adheres to the foam
while it dries. The foam, with the attached foam coat, is then removed
from the metal negative and sanded to smoothed out its surface. Present
building codes require the use of a fire rated coating material over foam,
such as foam coat. Unfortunately, the production rate of the
aforementioned process is limited to the number of metal negatives. In
addition, significant time is required to properly position the foam
within the negative and maintain its position so that a generally even
layer of foam coat is applied thereon. Unfortunately, the foam coat
frequently does not have an even surface using such a technique. Moreover,
the foam coat dries into a hardened material, substantially harder than
the underlying foam, which is difficult to sand smooth because of the
fibre material in the foam coat. Further, the fibre reinforcement within
the foam coat makes it difficult to sand the trim in a manner to provide
sharp corners, which is a frequently desired shape for trim. Accordingly,
when using such a product all of the corners much be round, even if such a
rounded corner design is not desired. Also, such a construction process is
labor intensive and is difficult to maintain a sufficiently high quality
output. In addition, it is difficult to manually coat the foam with foam
coat because unhardened foam coat is a gooey, sticky material which does
not flow well nor spread evenly.
The traditional method for attachment such trim detail involves fastening
the trim detail with glue or screws to the structure. Thereafter, the next
piece of trim detail is likewise fastened with glue or screws to the
structure adjacent to the previous trim detail. A joint remains between
the two pieces of trim detail that needs to be covered and secured
together. A mesh tape is overlaid on the joint and then foam coat material
is overlaid on the mesh tape. Unfortunately, the mesh tape has a tendency
to float within the foam coat material and thus additional layers of foam
coat material may be necessary to cover the mesh tape. The resultant
buildup of foam coat material may be difficult to smoothed out to make the
joint unnoticeable. Further, significant time is required to cover such
joints using the traditional method, which is expensive.
What is desired, therefore, is a molding that is both inexpensive to
manufacture and inexpensive to install. Further, the molding should comply
with the fire retardant building standards, have a hard exterior surface
to resist being inadvertently damaged, quickly finish to a smooth exterior
surface that may include sharp corners, provide any desired shape, and
manufacturable in large quantities without excessive labor costs.
SUMMARY OF THE INVENTION
The present invention overcomes the aforementioned drawbacks of the prior
art by providing a trim detail system with trim detail having an exterior
surface with a contour for attachment to a structure. The trim detail
includes a base material, such as foam, having an exterior surface with a
contour generally matching the contour of the trim detail. A first layer
of material, such as foam-coat, overlays the exterior surface of the base
material and is harder than the base material. A second layer of material,
such as a gypsum-based "drywall" material, overlays the first layer of
material and is softer than the first layer of material.
In the preferred embodiment the first layer is preferably gypsum-based,
provides the necessary fire rating, and hardens to a hardness
substantially greater than the underlying base material to provide
structural integrity to the trim detail. The second layer is preferably
gypsum-based "drywall" material which provides the benefits of being
easily sanded, easily spread and flows onto surfaces, easily finished to
both a smooth finish and sharp corners, if desired. Further, such a
gypsum-based second layer is inexpensive, reusable if it spills, and easy
to clean up with water. With the first layer and second layer both
gypsum-based they are compatible with one another and form a multi-layer
structure that maintains its integrity over time.
The system also includes a spreading machine with a table and container to
automate the manufacturing of the trim detail. With such a spreading
machine the multiple layers are easily spread evenly onto the base
material. Further, the spreading machine alleviates the difficultly
associated with troweling FC-90 Foam Coat material (first layer) as
suggested by the manufacturer which is a difficult process because
unhardened FC-90 Foam Coat is a gooey, sticky material which does not flow
well nor spread evenly.
The foregoing and other objectives, features, and advantages of the
invention will be more readily understood upon consideration of the
following detailed description of the invention, taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a piece of an exemplary embodiment of trim
detail of the present invention showing a base material, a protective
layer, and a finish coat.
FIG. 2 is a perspective view of the trim detail of FIG. 1 attached to a
structure.
FIG. 3 is a perspective view of two pieces of trim detail of FIG. 1 with
recessed portions at respective ends shown attached together to a
structure.
FIG. 4 is a spreading machine for the construction of the trim detail of
FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a piece of trim detail 10 includes a base material 12
which has an exterior surface 14 with a contour generally matching an
exterior contour 16 of the trim detail 10. The preferred base material 12
is foam, such as expanded polystyrene foam having a nominal density of 1.0
pound per cubic foot, a minimum density of 0.9 pound per cubic foot, a
maximum flame-spread rating of 25, and a smoke developed rating of no more
than 450. Alternatively, the base material 12 may be any suitable type of
material, such as for example, paper products, recycled paper, wood
products, and plastic. The selected base material 12 should be moldable,
suitable to being cut to the desired shape, and not susceptible to
warpage. The base material 12 is cut to the desired shape for the trim
detail 10.
A protective layer 20 is overlaid, or otherwise attached to and supported
by, the base material 12. The protective layer 20 is a thermal barrier
which complies with building codes, such as the 1994 Uniform Building
Code, requiring fire protection of the base material 12 for inclusion
within a building. Preferably the protective layer 20 is a gypsum-based
glass-fibre reinforced acrylic coating intended to be used as a foam
plastic thermal barrier. The protective layer 20 preferably contains 0.25
percent chopped fiberglass. The gypsum-based protective layer 20 is
preferably FC-90 Foam Coat Foam Plastic Protection from Hamilton
Materials, Inc. of orange, Calif. which is suitable for application
directly to expanded polystyrene foam base material 12. The FC-90 Foam
Coat material adheres well to foam, provides the necessary fire rating,
and hardens to a hardness substantially greater than the underlying base
material 12, such as foam. As such, the FC-90 Foam Coat material provides
structural integrity to the trim detail 10.
FC-90 Foam Coat is mixed with water at a ratio of approximately 2 gallons
of water per 25-pound bag of FC-90 Foam Coat. The mixing is by an electric
drill, with a paddle bringing the mixture to a working consistency. The
FC-90 Foam Coat may be troweled onto the base material 12 and cured for 24
hours to dry as it becomes significantly harder than the underlying base
material 12. Unfortunately, the toweling of the FC-90 Foam Coat material
as suggested by the manufacturer is a difficult process because unhardened
FC-90 Foam Coat is a gooey, sticky material which does not flow well nor
spread evenly. Accordingly, a spreading machine 60 is used to spread the
protective layer 20, as described later.
As previously described, the mere use of the FC-90 Foam Coat provides a
surface which is difficult to sand smooth because of the fibre material in
the foam coat, difficult to sand in a manner to provide sharp corners, and
is labor intensive. To overcome these limitations while still maintaining
the required standards of the 1994 Uniform Building Codes, the present
inventors came to the realization that a finish coat 30 of material may be
overlaid on the protective layer 20. The spreading machine 60 is used to
spread the finish coat 30, as described later. The finish coat 30 is
preferably a gypsum-based compound so that it is compatible with the
gypsum based protective layer 20 thereby making a good bond therebetween.
Such a gypsum-based compound may be selected from a class of compounds
generally referred as "drywall" compounds which are used in the
construction trade. Drywall compounds primarily include gypsum, glue, and
water. The preferred drywall compound is sold under the trade name
Hamilton's Topping Compound available from Hamilton Materials, Inc. of
Orange, Calif. Such a gypsum-based finish coat 30 provides the benefits of
being easily sanded, easily spread and flows onto surfaces, easily
finished to both a smooth finish and sharp corners, if desired. Further,
such a gypsum-based finish coat 30 is inexpensive, reusable if it spills,
and easy to clean up with water. The finish coat 30 may be any suitable
gypsum based product such as hot mud, joint compound, soft top (which
includes plastic), and light mud. Alternatively, the finish coat 30 may be
any other suitable type of material, such as for example, a cement based
product such as plaster (which typically includes cement, sand, silica
sand, acrylic primus ›glue!, lime, and color), and a colored stucco (which
typically includes primarily lime, some cement, and color).
The resulting finish coat 30 is then painted or finished in any suitable
manner desired by the particular application. Additionally, any suitable
number of additional layers may be added between the base material 12,
protective layer 20, and finish coat 30, as desired.
Referring to FIG. 2, the trim detail 10 is then adhered, or otherwise
attached, with glue or screws to an appropriate structure, such as a
corner 34 between a wall 36 and a ceiling 38. Depending upon the design of
the trim detail it may likewise be used at other appropriate locations
such as chair rails, capitals, pedestals, and columns. The trim detail 10
may also be used on the exterior of the structure, if desired.
Referring to FIG. 3, the trim detail 10 is constructed with at least one
end portion 40 where the exterior surface of the base material 12 is free
from overlaying by the protective layer 20 and the finish coat 30.
Likewise a similar trim detail 42 is constructed with at least one end
portion 44 where the exterior surface of the base material is free from
overlaying by the protective layer and the finish coat. The end portions
40 and 44 are created by taping over the end portions 40 and 44 of the
base material 12 which is thereafter removed together with the applied
protective layer 20 and finish coat 30 while still wet and non-hardened.
The ends portions 40 and 44 are recessed with respect to the remainder of
the trim details 10 and 42. The ends 45 and 46 of the respective trim
details 10 and 42 are adhered together with contact cement and the back
surfaces 48 and 50 of the trim details 10 and 42 are likewise coated with
contact cement, such as Fast Set Adhesive available from STO Corporation
of Atlanta, Ga. Thereafter, the trim details 10 and 42 are attached to a
suitable structure. The recessed portions of the end portions 40 and 44
are then coated with a protective layer, such as FC-90 Foam Coat, and a
finish coat until flush with the finish coat of the adjoining trim details
10 and 42. The use of the recessed portions allows for quicker assembly of
multiple trim detail portions while the protective layer overlaying the
recessed portions provides the necessary strength and fire rating, and the
finish coat is easily sanded flush with minimal time and effort. Further,
cementing the ends together prior to attachment to the structure provides
more accurate alignment of the trim detail pieces.
Referring to FIG. 4, the spreading machine 60 is suitable for producing
large quantities of trim detail 10 with minimal labor costs. The spreading
machine 60 includes a flat base 62, an upright side 64, and a flat top 66
preferably constructed from rigid metal. A lower guide bar 68 and upper
guide bar 70 are parallel to one another and the back corner 72 of the
spreading machine 60. A container 74 includes recessed portions 76 and 78
which slide on respective guide bars 68 and 70. The container 74 is
suitable to alternatively hold substantial amounts of the protective layer
material and the finish coat material. The sides 80 and 82 of the
container 74 support respective blades 84 and 86 that have an exterior
contour 88 and 90 that substantially matches the exterior contour of the
base material 100 and 102 supported by the spreading machine 60. During
use, the container 74 is filled with protective layer material and slid
across the base material 100 and stopped above the base material 102. Then
the base material 100 is removed and another piece of base material is
placed on the spreading machine 60 and coated with the protective layer
from the container 74. Another piece of base material 102 may be located
on the other end of the base material 100 to provide a place to stop the
container 74 above. In this manner the material within the container 74
does not spill onto the spreading machine 60 after passing beyond either
end of the base material 100. The protective layer material within the
container is then replaced with the finish coat material and the process
is repeated. The result is the multiple layer trim detail 10, as
previously described. Moreover, the spreading machine 60 provides
substantially even layers of material along the length of the base
material 12.
The container 74 may be pressurized to provide a more even layer of
material on the base material 12. In addition, the container 74 may be
motorized for movement, if desired.
The terms and expressions which have been employed in the foregoing
specification are used therein as terms of description and not of
limitation, and there is no intention, in the use of such terms and
expressions, of excluding equivalents of the features shown and described
or portions thereof, it being recognized that the scope of the invention
is defined and limited only by the claims which follow.
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