Method Of Forming A Block To Be Used In The Construction Of A Wall

Abstract

A method of forming a wall comprising preforming thin, rigid sheets with furring strips secured to their inner faces, then making building blocks by molding foamed plastic between the inner faces of a spaced pair of such sheets so that the sheets are bonded to and the furring strips are embedded within and bonded to the plastic, and including forming vertically extending holes through the plastic material and a horizontally extending channel along the upper edge of the plastic between the sheets. Next, stacking the blocks in courses to form a wall, with their vertical openings aligned with and their channels covered by the blocks next above them, and pouring concrete slurry into the openings and channels to form a concrete supporting grid within the wall. Thereafter, applying attachments to such sheets by means of mechanical fasteners engaged with said strips.

Parent Case Text

PRIOR APPLICATIONS

This application is a continuation-in-part of application Ser. No. 21,981, filed Mar. 23, 1970 and abandoned application Ser. No. 732,973, filed May 29, 1968.

Description

BACKGROUND OF INVENTION

The invention herein relates to improvements in a method of making foamed plastic building blocks and walls of the type shown, for example, in the patent to Moog, U.S. Pat. No. 3,410,044 of Nov. 12, 1968. Such type building blocks are laid in courses in a manner similarly to laying up a wall of concrete blocks. Concrete is poured into openings formed through the blocks, so that the blocks also act as a form.

Such prior foamed plastic blocks are relatively difficult and expensive to manufacture, are fragile and easily broken during handling and assembly operations, and the wall surface formed thereby is generally incapable of supporting wall attachments such as covering sheets, dry wall, plywood and the like, or electrical outlet boxes, medicine cabinets, cupboards, window frames, etc., due to the fact that mechanical fasteners, such as nails or screws, will not anchor into the foam plastic.

SUMMARY OF INVENTION

The invention herein relates to forming foamed plastic blocks out of a pair of pre-formed stiff, rigid sheets between which foamed plastic is molded to bond to the sheets and produce a composite block. The sheets are preformed with furring strips secured to their inner faces so that these strips embed into and are bonded to the plastic. The plastic body of each block is formed with a channel along its upper edge and vertical openings extending completely through the block so that upon assembly of a wall from such blocks, the channels in one block are closed by the lower edge of the block above it and concrete slurry poured into the channels and holes will solidify to form a cross-hatch type concrete grid within the wall.

The stiff, rigid sheets position and hold the furring strips in predetermined locations during the plastic molding, while simultaneously, the strips reinforce and stiffen the sheets both during molding as well as during pouring of the concrete into the wall. The furring strips also provide anchor points and load distribution means for supporting additional items to be fastened to the wall, such as dry wall finishing panels, electrical boxes, cupboards, etc.

Since the rigid sheets function as mold walls within which the plastic core or body of the block is molded, with the sheets then becoming integrated into the block as part of the composite lamination, the block molding process is considerably simplified, thus reducing costs. The finished block is lightweight, strong and not easily damageable. Thus, it may be made in large sizes, as for example, 6 feet by 3 feet in face dimension, therby reducing time and labor in forming a complete wall.

These and other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a block, with a portion of one of its face sheets cut away for illustrative purposes.

FIG. 2 is an enlarged, fragmentary, cross-sectional perspective view showing a joint between two blocks.

FIG. 3 is a plan view of a block, and

FIG. 4 is an elevational view, partially in cross-section, of the block.

FIG. 5 is a cross-sectional view taken in the direction of arrows 5--5 of FIG. 4.

FIG. 6 is an end view taken in the direction of arrows 6--6 of FIG. 4.

FIG. 7 is a fragmentary, perspective view of a portion of a wall.

FIG. 8 is a perspective view of a preformed sheet.

FIG. 9 is a view similar to FIG. 8 but showing a modified form of sheet.

FIG. 10 is a perspective view of a mold within which a block is formed.

FIG. 11 is a cross-sectional end view of the lower portion of the mold when opened.

FIG. 12 is a cross-sectional view of the closed mold.

DETAILED DESCRIPTION

FIG. 1 illustrates the relatively large size wall forming block 10, which may be, for example, 6 feet long by 3 feet high and about 10 inches thick or deep. The size and shape may vary considerably, but the construction described below, lends itself to the manufacture of blocks of a considerably greater size than conventional building blocks.

The block 10 is formed of a pair of preformed rigid sheets 11 made, for example, of stiff or rigid cardboard, either of single thickness or laminated double-faced corrugated cardboard, particle board, composition board, so-called "Masonite," plywood, aggregate covered board formed of stiff substrate coated with aggregate or stone and a binder, etc. These sheets may be relatively thick, such as on the order of one-eighth to one-quarter inch in thickness, more or less, so that they are stiff, self-sustaining and relatively rigid.

After the sheets are cut to size, a number of wood furring strips are secured to their inner faces, the strips being formed of conventional wood furring strip materials. Preferably, at least three strips are provided for each sheet, namely, an upper strip 12, a middle strip 13 and a lower strip 14, with the strips all being parallel, running horizontally and with the upper and lower strips preferably at the upper and lower edges of the sheet. For various specific purposes, the strips may be otherwise arranged upon the sheet and may be formed of different materials, such as metal. These strips may be fastened to the sheets by staples 15 or similar mechanical fasteners.

The block body portion 16 is formed of a foamed plastic material, such as a low density urethane or polystyrene or the like, molded and foamed in place between the two sheets 11 to form the composite block structure.

The upper edge of the plastic block body 16 is provided with a horizontally extending channel or groove whose upwardly open top will later be covered by the lower edge of the block next above it after the blocks are laid up into a wall. In addition, enlarged veritcal openings 18 extend completely through the block body.

A tongue 19 and a groove 20 are formed on the two opposite vertical ends of the block for interlocking with corresponding portions on adjacent blocks.

To form a building wall, the blocks are laid in courses, interlocked end to end and stacked one above the other. As illustrated in FIG. 2, the lower furring strips 14 of one block rests upon the upper furring strips 12 of the block beneath it so that these strips cooperate to form hardened, load bearing and load transmission rails or block body corners, in addition to functioning as furring strips.

After the blocks have been laid into the wall formation, conventional metal reinforcing rods 21 may be positioned through the aligned vertical openings of the blocks and also through the block upper edge grooves and thereafter concrete slurry may be poured into the openings to fill the openings and grooves.

The solidified concrete forms an internal grid 22 formed of vertical columns 23 and horizontal connectors 24, within the wall for supporting loads applied to the wall. Thus, the blocks function as forms for the pouring of the concrete. The plastic block material surrounding the poured concrete sections tends to keep the moisture in so that the concrete cures towards its maximum strength far more rapidly than is the case in conventional pouring of concrete.

Upon completion, the wall becomes a load bearing wall capable of supporting substantial loads, at the same time also giving the appearance and structure of a conventional wall, but with substantially increased insulation qualities.

Recesses or openings 25 may be cut into the sheets 11 and adjacent plastic body portions to receive various wall attachments, such as electrical outlet boxes, cabinets and cupboards and the like. Likewise, grooves 26 may be cut into the block surface for electrical wiring, etc. By way of example, FIG. 7 illustrates an electrical outlet box or junction box 27 mounted within a recess 25 cut in the wall surface, with electrical wiring 28 laid in a groove 26 so that the wiring is below the plane of the wall surface. The box may be secured to its adjacent furring strip 13 with nails or screws.

The wall surfaces may then be finished by applying wet plaster or stucco or the like. More typically, it may be finished by applying wall board or dry wall panels 30 fastened by nails 31 driven into the furring strips. The furring strips may be easily located behind the sheets 11 by observing the staples 15.

FIG. 9 illustrates a modified form of sheet 11a which is similar to the sheet 11 illustrated in FIG. 8, except that vertical furring strips 32 are provided. In addition, central frame strips 33 are secured to the sheet, with the sheet material between the strips 33 cut out at 34 to provide an opening which may be made of a size to accommodate a window frame, a medicine cabinet or the like. This illustrates that the furring strips and other similar strips may be attached to the panel 11 in various patterns for specific purposes.

METHOD OF FORMING BLOCKS

FIGS. 10-12 illustrate a mold suitable for making the above described blocks. The method in summary, is first preforming the sheets by cutting them to size and then applying the furring strips as described above. Thereafter, a pair of sheets are arranged parallel and spaced apart and the foam plastic material is molded between the sheets to join them together and to bond the sheets and plastic integrally.

During the molding process, the sheets preposition the furring strips in their predetermined locations and simultaneously, the furring strips stiffen or further rigidify the sheets and by embedding in the plastic, further lock the plastic and sheets together.

The mold 35, is formed in a box-like shape, with side walls 36, end walls 37, a base 38 and hinges 40 connecting the walls to the base. The walls may be swung open by suitable means, as for example, by connecting piston rods 41 to them, with the rods moved and arranged within conventional hydraulically operated cylinders 42 which are connected by brackets 43 to a floor support.

The mold cover 44 includes a channel forming portion 45 and depending forms 46 for molding the vertical openings within the plastic. The mold cover may be raised and lowered by a suitable hydraulic piston rod and cylinder mechanism 47.

As illustrated in FIG. 11, the mold side walls 36 are provided with upper and lower lips 49 so that preformed sheets 11 may be arranged against the inside surfaces of the walls 36, between the lips 49. Thereafter, the mold is closed by swinging the walls into the box forming position. After the cover of the mold is lowered, as illustrated in FIG. 12, the foamable plastic material may be inserted into the cavity and permitted to foam and cure into the shape of the block body portion.

EXAMPLE OF MOLDING

While the specific composition of the plastic and of the rigid outer sheet materials may vary, thereby varying molding conditions, an example of forming the foregoing block is as follows:

Starting with a sheet material formed of corrugated, double-faced cardboard of about 1/8 inches thick and furring strips made of fir or whitepine or the like, which is about 5/8 .times. 11/2 inches in cross-sectional dimension, and polyurethane plastic formable, with the addition of an appropriate foaming agent, to about a nominal 1.8 lbs per cubic foot density.

First, the wood strips are fastened to the sheets, with conventional heavy duty staples, after the sheets have been precut to size. The sheets are then inserted into the mold, that is, laid up against the side walls of the mold.

The foamable urethane plastic is added to the mold and the mold closed as illustrated in FIG. 12. The mold is heated to a temperature of approximately 135.degree. F. The plastic is molded, i.e., foamed in place, for roughly ten minutes, at which time the molding is complete. The plastic bonds to the sheets and furring strips forming an integrated structure.

The foamed plastic resulting from the molding may be roughly about two pounds per cubic foot.

Having fully described an operative embodiment of this invention, I now claim:

Claims

1. A method for forming wall blocks comprising: preforming thin, rigid sheets, such as of thick, stiff cardboard, wallboard, plywood and the like, to the size and shape of the opposed major, vertical faces of a wall forming block;

fastening along the length of the horizontal edges of at least one of the thin, rigid sheets, a relatively long and narrow, rigid furring strip;

vertically positioning a pair of the sheets with attached furring strips within a mold in spaced, face to face, parallel relationship, whereby the furring strips reinforce and stiffen the vertically positioned sheets during molding and the sheets simultaneously pre-position and hold the strips in predetermined position during molding so that the sheets are maintained relatively flat and the strips are simultaneously embedded within and bonded to the molding material;

covering the outward, horizontal faces of the furring strips with a mold portion to shield said face from the molding material to thereby produce an exposed furring face, whereby the exposed face in the finished product enables the furring strip to act as a load bearing element;

closing the end gaps defined by the spaced sheets with portions of the mold;

molding a foam plastic material in place in between the spaced sheets, and thereby bonding the foam material to the sheets and attached furring strips to form a composite block; and

during the molding step, forming within the foam inner layer vertical openings extending the length of the component block.

2. The method of forming wall blocks defined in claim 1, further including the step of covering a portion of the inward face of at least some of the furring strips with a mold component to shield that portion of the inward face from molding material to define a further exposed, load bearing surface on the furring strip.