US 3857217 A
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.
Description (OCR text may contain errors)
United States Patent 1191 Reps 1451 Dec. 31, 1974 3,249,659 5/ 1966 Voelker 16l/69 LIGHTWEIGHT, RIGID STRUCTURAL 967 Ch k l A E F WALL CEILIN AND THE 3,328,932 7 1 es in 52 577 5 OR Gs 3,529,389 9/1970 Wilkins 52/281  Inventor: William F. Reps, Route 355 and FOREIGN PATENTS OR APPLICATIONS Route 80, Urbana, Md, 723,621 2/1955 Great Britain 161/69  Filed: 1972 Primary Examiner-Henry C. Sutherland  Appl. No.: 306,928 Assistant Examiner-James L. Ridgill, Jr.
' Attorney, Agent, or Firm-.1. T. Martin; Gerald D. 52 us. 01 52/589, 52/576, 161/68, Fergusm' Seph Baker 161/ 159  Int. Cl E04c 1/10, E040 2/36 ABSTRACT Field of Search 161/69, 52/576, A structural panel is disclosed having a core compris- 405, 7 580 ing a plurality of recesses or tubular-shaped passage ways formed of web material which open onto oppol References Cited site sides of the core. A first layer of woven material is UNITED STATES PATENTS positioned adjacent the openings on one side of the 1 875,131 8/1932 Pentland .Q 52/577 and a layer material is P081- 11972592 9/1934 Jacobson 161/68 tioned adjacent the openings on the other Side of the 2,639,606 /1953 Boss et a1 52/589 core. A covering of cementatious material completely 2,692,219 10/1954 Slayter et a1 52/ 144 surrounds the core partially filling the recesses or 2,828,235 3/1958 Holland et a1. 52/618 tubular-shaped passageways to form the panel.
2,839,442 6/1958 Whitaker 161/68 2,951,004 8/1960 Martin et a1. 161/68 7 Chums, 4 Drawing Figures W 34-- --'["']'J- /-/'-/JZ- 1' .17 j J /-J' u" "i l 11717 A/ 'Z I l u 2 86 ii i 1 1o 10 i ,..7 ,7. ',/,/7 ./Z.. H .j. 6mm w LIGHTWEIGHT, RIGID STRUCTURAL PANEL FOR WALLS, CEILINGS AND THE LIKE 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 fromreadily 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. Toprevent 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 difficultto use in many applications. The cost of these prior art panels is also substan'-""" long curing time and readily transmit heat orcold due to the poor insulating qualities als and metal. i
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. I
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.
of concrete-type materi- 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 viewof 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(0).
FIG. 4 is a perspectiveview 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 l4 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 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 l4.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 thepanel 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 crosssection 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 therece'sses 14 on one side of the core 12. Cementatious material l0.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 havea 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 portio'ns 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 intothe recesses 14, a distance of approximately one-half inch. Alayer 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(a).
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 permittedto 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 re cesses 14 aids in the curing process. The finished panel is then removed from the mold. I
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 asf 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 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.
What I claim is:
l. 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 tosecure 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.