U.S. patent number 3,857,217 [Application Number 05/306,928] was granted by the patent office on 1974-12-31 for lightweight, rigid structural panel for walls, ceilings and the like.
Invention is credited to William F. Reps.
United States Patent |
3,857,217 |
Reps |
December 31, 1974 |
LIGHTWEIGHT, RIGID STRUCTURAL PANEL FOR WALLS, CEILINGS AND THE
LIKE
Abstract
A structural panel is disclosed having a core comprising a
plurality of recesses or tubular-shaped passageways formed of web
material which open onto opposite sides of the core. A first layer
of woven material is positioned adjacent the openings on one side
of the core and a second layer of woven material is positioned
adjacent the openings on the other side of the core. A covering of
cementatious material completely surrounds the core partially
filling the recesses or tubular-shaped passageways to form the
panel.
Inventors: |
Reps; William F. (Urbana,
MD) |
Family
ID: |
23187495 |
Appl.
No.: |
05/306,928 |
Filed: |
November 15, 1972 |
Current U.S.
Class: |
52/592.1;
428/188; 52/576; 428/116; 428/193 |
Current CPC
Class: |
B32B
5/024 (20130101); B32B 17/02 (20130101); E04C
2/36 (20130101); B32B 2315/085 (20130101); Y10T
428/24149 (20150115); Y10T 428/24744 (20150115); Y10T
428/24785 (20150115) |
Current International
Class: |
E04C
2/34 (20060101); E04C 2/36 (20060101); EO4c
001/10 (); EO4c 002/36 () |
Field of
Search: |
;161/69,68,159
;52/576,577,618,625,615,405,589,576,577,580 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Sutherland; Henry C.
Assistant Examiner: Ridgill, Jr.; James L.
Attorney, Agent or Firm: Martin; J. T. Ferguson, Jr.; Gerald
D. Baker; Joseph J.
Claims
What I claim is:
1. A lightweight, rigid, structural panel of cementatious material
comprising:
a. a core consisting of webbed material having a plurality of
open-ended, separate tubular recesses of substantially equal
height, a layer of very fine mesh reinforcing material adjacent to
and covering one end of said recesses, said fine mesh material
having a mesh on the order of ten per linear inch to insure the
passage therethrough of only a sufficient amount of said
cementatious material into said recesses to secure said layer of
fine mesh material to said core, and a layer of coarse mesh
material adjacent and covering the other end of said recesses, said
coarse mesh material having a mesh on the order of four per linear
inch to insure the ready passage therethrough of a greater amount
of said cementatious material into said recesses than said first
layer to secure said permeable material to said core, and
b. cementatious material covering said fine and coarse mesh
material and said entire core to form a monolithic panel, said
layers of fine and coarse mesh reinforcing material, when secured
to said webbed material by said cementatious material, serve to
prevent said panel from flexing under applied loads.
2. A structural panel as set forth in claim 1 further comprising a
tongue formed on one surface of said panel and a groove formed on
the other surface of said panel.
3. A structural panel as set forth in claim 2 wherein said
cementatious material has reinforcing elements dispersed throughout
it.
4. A structural panel as set forth in claim 2 wherein said
cementatious material extends into said recesses, a distance of
approximately one-half inch.
5. A structural panel as set forth in claim 2 wherein said fine
mesh and said permeable material are secured to said core by tying
means extending through said hollow recesses.
6. A structural panel as set forth in claim 1 wherein said fine
mesh and said coarse mesh woven material is fiberous.
7. A structural panel as set forth in claim 2 wherein said webbed
material is fiberous.
Description
BACKGROUND OF THE INVENTION
This invention relates to structural panels and more particularly
to a lightweight molded panel structure and method of manufacturing
the molded panel.
There has long been a need in the construction industry for a
structural panel which can be easily and rapidly fabricated by
unskilled labor from readily available inexpensive materials in
sizes ranging from that of a common building block to a single
piece wall or ceiling structure while at the same time being rigid
and of lightweight.
Present methods of manufacturing cement-type panels of any
appreciable size usually result in a high rate of rejection due to
warpage or other internal defects. To prevent warping during
manufacture or serious deflection under load, many prior art panels
employ reinforcing devices encased in the cement-type material such
as steel rods or other honeycomb metal structures. The
aforementioned devices have solved the warping and deflection
problems to a degree in the fabrication of large size panels,
however, in doing so, the weight of the panel is considerably
increased due to the added weight of the metal being used which in
turn makes the panel impractical or difficult to use in many
applications. The cost of these prior art panels is also
substantially increased due to the cost of the various metal
reinforcing devices. In addition, such panels require a long curing
time and readily transmit heat or cold due to the poor insulating
qualities of concrete-type materials and metal.
The present invention overcomes the aforementioned problems by
providing a panel which can be constructed in sizes large enough
for use as entire walls or ceilings or in small block size. The
panel is lightweight, extremely rigid and can be manufactured by
unskilled labor with simple, low cost forming apparatus and of low
cost material. The panel cures rapidly and has excellent insulating
characteristics to temperature as well as being resistant to
insects and other vermin. Further, because of its unique design,
the panel of the present invention can be constructed of a great
variety of materials without significantly altering its structural
rigidity; thus, making it suitable for fabrication and use in
underdeveloped countries where only building materials of a
primitive nature exist.
SUMMARY OF THE INVENTION
The panel structure of the present invention comprises a core
consisting of ribboned or webbed material which are joined together
to form a plurality of recesses or tubular-shaped passageways. Each
tubular-shaped passageway opens into an upper and a lower surface
of the core. A first layer of large mesh, screen-like material is
located adjacent the lower surface of the core so as to cover all
of the openings in the lower surface. A second layer of small mesh,
screen-like material is located adjacent the upper surface of the
core so as to cover all of the openings in the upper surface. A
covering of cementatious material completely surrounds the first
and second layers of screen-like material as well as the portion of
the core not covered by the first and second layers of screen-like
material to form the panel.
In producing the panel, an amount of cementatious material is first
poured into the bottom of a cavity in a mold. The shape and size of
the mold cavity being the shape and size of the finished panel. The
first layer of large mesh, screen-like material is centered on the
cementatious material. The core is then centered on the first layer
such that the openings on one surface of the core are adjacent the
first layer. The core is then pressed toward the cementatious
material causing the material to flow through the first layer and
into the tubular passageways of the core a specified distance. A
second layer of small mesh, screen-like material is centered on the
core such that the openings on the other surface of the core are
covered by the second layer. The remainder of the mold cavity is
then filled with cementatious material and permitted to cure before
removal from the mold as the finished panel.
The small mesh of the screen-like material of the second layer
permits only a very small amount of cementatious material from
passing through the mesh into the tubular passageways. The tubular
passageways therefore remain substantially hollow, thus,
considerably reducing the overall weight of the panel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in perspective of a building block or panel made
according to the invention having tongue and groove construction at
opposite ends of the block.
FIGS. 2 (a-c) is a plan view of the steps of forming the core in a
mold of the building block or panel of the present invention.
FIG. 3 is a sectional view of the building block or panel taken
along the lines 3 -- 3 of FIG. 2(c).
FIG. 4 is a perspective view showing the relationship of the
elements forming the core of the building block or panel of the
present invention.
DESCRIPTION OF THE INVENTION
Referring now to the drawing, the panel as shown in FIG. 1 consists
of an outer surface or layer 10 of cementatious material. The
cementatious material 10 can be gypsum, lime, lightweight concrete,
wood fiber concrete, or cellular concrete. The present invention is
not concerned with the particular cementatious material per se, and
it will be understood that cementatious materials other than those
specified above can be used as long as they are strong and of
lightweight.
The panel also consists of a core 12 having a plurality of recesses
or tubular-shaped passageways 14 formed of webbed material 16. The
webbed material 16 forming the core 12 may be of any suitable
lightweight material such as paper, resin impregnated paper or the
like. Paper impregnated with other chemicals can be used to render
the paper fire, insect and vermin resistant.
The recesses or tubular-shaped 14 passageways may be semi-circular
as shown, honeycomb, or other configurations which provide a rigid
structure. The air entrapped in the recesses greatly increase the
insulating properties of the panel.
A layer of reinforcing material 18 is positioned adjacent the
openings of the recesses 14 on one side of the core 12. The
reinforcing material 18 serves to strengthen the panel and render
the core 12 more rigid and resistant to flexing under load. The
reinforcing material 18 can be steel wire, wire fabric which is
welded, woven or twisted, filaments of other metals, woven fibers
of jute, hemp, bamboo, cane or the like. The reinforcing material
18 also serves to protect the core 12 from damage due to an impact
on the surface 10 adjacent the material 18 as well as prevent
cracking of the surface 10 as a result of such impacts. The
reinforcing material 18 can be in the form of a woven sheet made of
the aforementioned materials or it may be in the form of metal
filaments or non-metallic fibers dispersed throughout the mass of
the cementatious material forming the outer surface 10. If the
reinforcing material 18 is a sheet of woven material, the mesh of
the material should be sufficiently large to permit cementatious
material forming the outer surface 10 to enter the recesses 14.
Such a mesh would be, for example, one of four to the linear
inch.
A layer of material 20 substantially impervious to the passage of
the cementatious material forming the outer surface 10 is
positioned adjacent the openings of recesses 14 on the other side
of the core 12. The layer of material 20 can be woven of the same
materials previously described with respect to reinforcing material
19; however, the mesh of the material 20 would be very fine, for
example, on the order of ten to the linear inch. The layer of
material 20 serves a dual function, one of which is to provide
further rigidity to the panel structure and the other of which is
to prevent all but a very small amount of the cementatious material
10 from entering and filling the recesses 14. The small amount of
cementatious material 10, which does pass through the fine mesh,
secures the cementatious material 10 to the woven material 20 as
well as to the core 12.
In order to insure that the cementatious material 10 and the woven
material 20 remain adjacent the core 12, wire, cord or other
suitable tying means 22 can be passed through the recesses 14 and
through the mesh of the layers 18, 20 and tied in the manner shown
in FIG. 4.
The finished panel as shown in FIG. 1 and the cross-section thereof
shown in FIG. 3 has the core 12 thereof positioned substantially in
the center of the panel. The layer of reinforcing material 18 is
positioned adjacent the openings of the recesses 14 on one side of
the core 12. Cementatious material 10 is permitted to extend
through the mesh of the reinforcing material 18 into the recesses
14 a predetermined distance as will be described in greater detail
later. The layer of substantially impervious material 20 is
positioned adjacent the openings of the recesses 14 on the other
side of the core 12 and a small amount of cementatious material 10
extends through the mesh of material 20 into the recesses 14.
Cementatious material 10 also surrounds the sides of the core 12 to
complete the panel structure. The panel can have a tongue 24 and a
groove 26 to facilitate alignment as well as sealing of adjacent
panels. It being understood, of course, that the tongue 24 and the
groove 26 can be eliminated or modified and that the panel
structure itself can be made in any size ranging from that of a
conventional-size building block to an entire one-piece wall or
ceiling panel.
Having described the panel itself, the method of manufacturing the
panels will now be described. The cementatious material 10 is
prepared having a consistency suitable for molding but not too
loose so as to permit the cementatious material 10 to readily pass
through the mesh of material 20.
A mold is then provided having an internal cavity the size and
configuration of which is the external size and configuration of
the desired panel. Referring to FIGS. 2 and 3, a typical mold for
forming the panel shown in FIG. 1 has a rectangular frame with side
portions 28 which rest on the flat surface 29 of supporting
structure 30. Spaced apart end portions 32, 34 are secured between
side portions 28 and the supporting structure 30. End portion 32
has a recess 36 for forming the tongue 24 and end portion 34 has a
protuberance 38 for forming the recess 26 of the panel.
An amount of the previously prepared cementatious material 10 is
poured into the mold cavity to completely cover the bottom surface
29 of supporting structure 30 and partially fill the mold cavity. A
layer of reinforcing material 18 is then placed and centered on the
fresh, unhardened cementatious material 10 as shown in FIG. 2(a).
The reinforced core 12 is then placed on the reinforcing material
18 as shown in FIG. 2(b) and sufficient pressure is exerted on the
core 12 to force the cementatious material 10 through the mesh of
material 18 and into recesses 14 of the core 12. Pressure is
exerted on core 12 until the cementatious material 10 extends into
the recesses 14, a distance of approximately one-half inch. A layer
of substantially impervious material 20 is then placed on top of
the core 12 to cover the adjacent openings of the recesses 14 as
shown in FIG. 2(c).
The mold cavity is then completely filled with cementatious
material 10 to thereby encase the core 12, reinforcing material 18
and impervious material 20. The entire mold may then be vibrated
slightly to ensure complete encasement of the core 12, however, the
vibration should not be of such duration so as to allow the
cementatious material 10 to pass through the fine mesh of material
20 and fill the recesses 14.
The cementatious material 10 is then permitted to remain in the
mold cavity for a time period until completely cured which time
period is of relatively short duration due to the fact that the air
trapped in the recesses 14 aids in the curing process. The finished
panel is then removed from the mold.
If the reinforcing material is in the form of metal filaments or
non-metallic fibers dispersed throughout the cementatious material
10 rather than in the form of a woven sheet 18 as shown in FIGS. 2
and 4, the core 12 would be pressed directly into the cementatious
material 10 containing said filaments or fibers. For additional
strength, cementatious material having the aforementioned filaments
or fibers could be used together with a woven sheet of reinforcing
material. When tying wire 22 or the like is used, the woven
material 18, 20 can be secured to the core 12 before the core 12 is
immersed into the cementatious material 10. In addition, if the
tongue 24 and groove 26 are subjected to stress, the reinforcing
material 18 can be wrapped entirely around the four sides of the
core 16 in order to hold the cementatious material 10 forming the
sides, tongue 24 and the groove 26 to the core 16. Further, if a
less rigid panel is acceptable for its intended use, the woven
sheet of reinforcing material 18 can be eliminated and only the
core 12 immersed into the cementatious material 10, the
aforementioned predetermined distance. The woven sheet of
reinforcing material 20 can then be placed on the core 12 or
secured to the core 12 by tying wire 22 before the core 12 is
immersed in the cementatious material 10 to thereby prevent the
cementatious material 10 from filling the recesses 14.
If an ornamental panel is desired, the flat surface 29 can be
shaped with various designs which will then be formed on the
outside surface of the panel. Pigment of various colors can also be
added to the cementatious material 10 if colored panels are
desired.
While I have shown and described a preferred form of my panel and a
preferred method of making my panels, it will be obvious to those
skilled in the art that various changes and modifications may be
made without departing from the spirit of my invention or the scope
thereof as set forth in the appended claims.
* * * * *