Insulating Device for Building Foundation Slab

Abstract

A device for insulating the slab foundation of a building, said device comprising: a generally horizontal insulating section disposed between the slab foundation and a footer of a building, said horizontally disposed insulating section comprising a generally elongated cuboid shape having at least one cutout through which a concrete column is disposed; said prefabricated device further comprising a generally vertical insulating section disposed adjacent to said horizontal insulating section and attached to said building.

Claims

1. A device for insulating the slab foundation of a building, said device comprising: a generally horizontal insulating section disposed between the slab foundation and a footer of a building, said horizontally disposed insulating section comprising a generally elongated cuboid shape having at least one cutout through which a concrete column is disposed; said prefabricated device further comprising a generally vertical insulating section disposed adjacent to said horizontal insulating section and attached to said building.

2. The device of claim 1, wherein the device is prefabricated and comprises a material selected from the group consisting of extruded foam, polyisocyanurate foam, expanded foam, insulated foil bubble wrap, and blown insulation.

3. The device of claim 1, wherein the material comprises an additive selected from the group consisting of an insecticide, an herbicide, a fungicide, and a water repellant.

4. The device of claim 1, wherein the vertical insulating section further comprises a semi rigid external sheath.

5. The device of claim 1, further comprising a vertical metal bar disposed through at least one column, where the bar comprises a material selected from the group consisting of steel, iron, and metal alloy.

6. The device of claim 1, further comprising a horizontal metal bar disposed across the device through and perpendicular to the at least one column, where the bar comprises a material selected from the group consisting of steel, iron, and metal alloy.

7. The device of claim 1, wherein each concrete column is capable of bearing a vertical load of at least about 20,000 pounds.

8. The device of claim 1, wherein the device has an R-value of at least about 5 per inch of material thickness.

9. A device for insulating the slab foundation of a building, said device horizontally disposed between the slab foundation and footer of a building, said device comprising a generally elongated cuboid shape having at least one cutout through which a concrete column is disposed.

10. The device of claim 9, wherein the device is prefabricated and comprises a material selected from the group consisting of extruded foam, polyisocyanurate foam, expanded foam, insulated foil bubble wrap, and blown insulation.

11. The device of claim 9, wherein the material comprises an additive selected from the group consisting of an insecticide, an herbicide, a fungicide, and water repellant.

12. The device of claim 9, further comprising a vertical metal bar disposed through at least one column, where the bar comprises a material selected from the group consisting of steel, iron, and metal alloy.

13. The device of claim 9, further comprising a horizontal metal bar disposed across the device through and perpendicular to the at least one column, where the bar comprises a material selected from the group consisting of steel, iron, and metal alloy.

14. The device of claim 9, wherein each concrete column is capable of bearing a vertical load of at least about 20,000 pounds.

15. The device of claim 9, wherein the device has an R-value of at least about 5 per inch of material thickness.

16. A method of insulating the slab foundation of a building, said method comprising the steps of: providing a footer for a building; providing a horizontally disposed insulating device, said device comprising a generally elongated cuboid shape having at least one vertically disposed cutout therethrough; pouring a concrete slab foundation for the building such that structurally supportive columns for the slab are created through the cutouts.

17. The device of claim 16, wherein the device is prefabricated and comprises a material having an R-value of at least about 5 per inch of thickness and wherein the material is selected from the group consisting of extruded foam, polyisocyanurate foam, expanded foam, insulated foil bubble wrap, and blown insulation.

18. The device of claim 16, wherein the material comprises an additive selected from the group consisting of an insecticide, an herbicide, a fungicide, and water repellant.

19. The device of claim 16, further comprising: a vertical metal bar disposed through at least one column; and a horizontal metal bar disposed across the device through and perpendicular to the at least one column, where the bars comprise a material selected from the group consisting of steel, iron, and metal alloy.

20. The device of claim 16, wherein each concrete column is capable of bearing a vertical load of at least about 20,000 pounds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of exemplary embodiments of the present invention. However, the drawings and descriptions herein should not be taken to limit the invention; they are for explanation and understanding only.

[0051] FIG. 1 is a cross-sectional view of a typical monolithic building foundation slab with a prior art insulation system.

[0052] FIG. 2 is a cross-sectional view of a typical non-monolithic building foundation slab with a prior art insulation system.

[0053] FIG. 3 is a cross-sectional view of a slab insulation device according to a first embodiment of the present invention.

[0054] FIG. 4 is a cross-sectional view of non-monolithic building foundation slab with the slab insulation device of FIG. 3 attached to a building having a slab.

[0055] FIG. 5 is a side cross-sectional view of a building foundation slab with an attached slab insulation device according to a second embodiment of the present invention.

[0056] FIG. 6 is a top view of a footer insulating member according to a second embodiment of the present invention.

[0057] FIG. 7 is a perspective view of an installed footer insulating member according to a second embodiment of the present invention.

[0058] FIG. 8 is a top view of an embodiment of a footer insulating member according to a third embodiment of the present invention.

[0059] FIG. 9 is a top view of a wall section of a footer insulating member according to the embodiment of the present invention that is shown in FIG. 8.

[0060] FIG. 10 is a top view of a corner section of a footer insulating member according to the embodiment of the present invention that is shown in FIG. 8.

[0061] FIG. 11 is a side cross-sectional view of a footer insulating member according to the present invention.

[0062] FIG. 12 is a top cross-sectional view of a footer insulating member according to the present invention.

[0063] Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] The present invention will be discussed hereinafter in detail in terms of the preferred embodiment according to the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structures are not shown in detail in order to avoid unnecessary obscuring of the present invention.

[0065] The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word exemplary or illustrative means serving as an example, instance, or illustration. Any implementation described herein as exemplary or illustrative is not necessarily to be construed as preferred or advantageous over other implementations.

[0066] All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. In the present description, the terms upper, lower, left, rear, right, front, vertical, horizontal, and derivatives thereof shall relate to the invention as oriented in FIG. 1.

[0067] Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0068] Referring to FIG. 1, there is shown a typical monolithic floating slab for the foundation of a residential or commercial building with a prior art insulation system. As shown in FIG. 1, a typical, monolithic, floating slab foundation system comprises a concrete slab; a gravel layer; strength enhancing, and, preferably steel reinforcement members within the slab.

[0069] As shown in FIG. 1, this prior art system may further comprise a rigid insulating sheathing disposed against an exterior edge of the slab and a plastic or rubber gasket membrane disposed on the ground facing, exterior wall of the rigid sheathing. The membrane functions to protect the insulation from damage due to pest infestation or moisture.

[0070] Referring still to FIG. 1, an exterior wall of a residential or commercial building disposed on top of the slab foundation and the membrane is shown. The building wall may have exterior and interior insulating sheathing.

[0071] One problem with the prior art system shown in FIG. 1 is that a break exists between the above ground and below ground exterior insulation. Consequently, significant heat can escape the building through the slab and between the two insulation segments.

[0072] Referring now to FIG. 2, there is shown a typical non-monolithic floating slab for the foundation of a residential or commercial building with a prior art insulation system. As shown in FIG. 2, the slab is poured such that it comprises a generally horizontal top and a plurality of vertical walls disposed around the perimeter of the horizontal top. The walls are entrenched in the ground, preferably at a depth of about 3 feet. As further illustrated in FIG. 2, the vertical perimeter walls rest on a footer. The slab further includes a plurality of reinforcing members disposed vertically within the slab. The reinforcing members are oriented such that they cross from the perimeter walls of the slab into and through the horizontal top portion of the slab.

[0073] Referring again to FIG. 2, the horizontal top of the slab rests atop a layer of gravel. A polymer membrane is disposed atop the layer of gravel, and a horizontal layer of foam insulation is disposed between the polymer membrane and the bottom of the horizontal portion of the slab. The foam insulation provides a thermal break for the slab and functions as a mechanical expansion joint. The polymer membrane prevents moisture from damaging the horizontally disposed foam insulation layer.

[0074] Referring again to FIG. 2, there is shown a frame around the vertical walls of the slab. The frame itself has two vertical walls that sandwich the vertical perimeter walls of the slab as shown in FIG. 2. As further illustrated in FIG. 2, the exterior walls of a building rest on the slab foundation such that they are generally collinear with the perimeter walls of the slab. The walls of the building generally comprise an interior drywall layer and an exterior insulating sheathing layer. A polymer membrane is disposed between the bottom of the building exterior walls and the top of the horizontal portion of the slab.

[0075] Much like the prior art slab insulation system of FIG. 1, a problem with the prior art system shown in FIG. 2 is that a break exists between the above ground and below ground exterior insulation. Consequently, significant heat can escape the building through the slab and between the two insulation segments, as well as through the gap between the exterior wall of the building and the horizontal portion of the slab.

[0076] A second problem with the prior art system shown in FIG. 2, is that the interior flooring in such a system cannot be secured without breaking or coming loose in the corners such that certain desirable floorings, such as tile, cannot be used. Past methods such as bringing the interior foam to the top of the slab with a beveled edge on the top of the slab have caused deflection between the slab and footer area of slab, and separation between slab and footer area of slab due to lack of a monolithic pour with the foam being the barrier.

[0077] Referring now to FIG. 3, there is shown a cross-sectional view of a slab insulation device according to a first embodiment of the present invention. As shown in FIG. 3, device 1000 generally comprises a substrate 100, a reflective layer 200, and a sheathing layer 300.

[0078] Referring again to FIG. 3, substrate 100 is comprised of a durable, inexpensive, corrosion resistant material suitable for securely retaining the remaining elements of slab insulation device 1000. Preferably, substrate 100 is comprised of vinyl. However, those of skill in the art will appreciate that any durable, reasonably structurally sound material such as wood, composite, or polymer will suffice. A flexible polyethylene foam gasketing strip attached to the interior of the product as it attaches to the slab may also be included.

[0079] As further illustrated in FIG. 3, thermal barrier 1000 further comprises sheathing layer 300. Sheathing layer 300 preferably comprises and insulating material such as polyisocyanurate with a thickness within a range of from about 1 inches to about 2 inches. A thickness of 1 results in an R-value of 5-7. Thus, the thickness of insulating sheathing layer 300 can be increased or decreased to achieve a desired R-value.

[0080] Those of skill in the art will appreciate that a number of materials may be used for sheathing layer 300, including extruded foam, polyisocyanurate foam, expanded foam, and insulating foil bubble wrap material or similar material.

[0081] Referring again to FIG. 3, a reflective layer 200 is disposed between substrate 100 and sheathing layer 300. Reflective layer 200 comprises a material such as aluminum. As further illustrated in FIG. 3, reflective layer 200 may be attached to one side of sheathing layer 300.

[0082] Referring still to FIG. 3, in the preferred embodiment, the elements of slab insulation device 1000 are secured to one another such that they form a singular device. Although slab insulation device 1000 may be of any desired size and shape, it is preferable for it to have a rectangular shape with a length ranging from about 4 feet to about 8 feet.

[0083] As shown in FIG. 3, slab insulation device 1000 further comprises bottom nailing strip 400. Nailing strip 400 is disposed such that it attached to substrate 100 and abuts the bottom of insulating sheathing layer 300. Nailing strip 400, used so that slab insulation device 1000 may be nailed to the exterior of a residential or commercial building, comprises a wood or composite material, preferably plywood.

[0084] As further illustrated in FIG. 3, slab insulation device 1000 may further comprise top nailing strip 500. Nailing strip 500 preferably comprises a vertical extension of vinyl substrate 100. Although the preferred embodiment of slab insulation device 1000 is designed to be nailed to the exterior of a building, those of skill in the art of construction will appreciate that other securing methods or means are suitable for attaching slab insulation device 1000 to a building, such as tacks, screws, adhesives, tape, snap-fit, tab and groove, or a combination of these methods. Additionally, slab insulation device 1000 may comprise a final external protective polymer layer (not shown) opposite said substrate 100.

[0085] Referring now to FIG. 4, there is shown a cross-sectional view of slab insulation device 1000 attached to the exterior of a residential building having slab foundation. As shown in FIG. 4, slab insulation device 1000 is preferably nailed to the exterior of a building such that device 1000 extends vertically below the horizontal layer of the slab foundation of the building and below the uppermost portion of any insulation on the interior of the slab perimeter wall. Thus, heat loss through the slab foundation of the building is diminished.

[0086] Referring now to FIG. 5, there is shown an alternative embodiment of the present invention. As shown in FIG. 5, slab insulation device 5000 provides continuous insulation around the exterior perimeter of the building's slab foundation and between the slab and the footer. This continuous insulation (with no thermal break) provides even greater prevention of heat loss through the slab foundation.

[0087] Referring still to FIG. 5, slab insulation device 5000 generally comprises an exterior insulating member 5100, a footer insulating member 5200, and an internal insulating member 5400. As shown in FIG. 5, each of the above described insulating members is generally in continuous contact with one another and the slab such that there is no air gap between the perimeter of the slab and ambient conditions or between the perimeter of the slab and the footer.

[0088] Referring again to FIG. 5, exterior insulating member 5100 of slab insulation device 5000 preferably comprises an insulating material such as expanded polystyrene, polyisocyanurate, or extruded polystyrene. [0089] Polyisocyanurate (polyiso for short) foam has the highest R-value per inch (R-6.5 to R-6.8) of any rigid insulation. This type of rigid foam usually comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier in some applications. Polyiso board is more expensive than other types of rigid foam. Extruded polystyrene (XPS) rigid foam is usually blue or pink in color, with a smooth plastic surface. XPS panels typically aren't faced with other material. The R-value is about 5 per in. This type of rigid foam won't absorb water like polyiso and is stronger and more durable than expanded polystyrene, so it's probably the most versatile type of rigid foam. XPS falls between polyiso and expanded polystyrene in price. Expanded polystyrene (EPS) is the least-expensive type of rigid foam and has the lowest R-value (around R-3.8 per in.). It's also more easily damaged than the other types of rigid foam.
Dr. Energy Saver Home Services, Rigid Insulation Board: R-value Packed into a Rigid Foam Panel, available at http://www.drenergysaver.com/insulation-materials/rigid-insulation-board.html (last visited Dec. 27, 2012).

[0090] However, persons of ordinary skill in the arts of building construction or thermal insulation will appreciate that any convenient insulation material will suffice as long as it meets or can be adapted to meet the configuration of the present invention and any applicable construction regulations. Preferably, exterior insulating member 5100 is of semi-rigid construction.

[0091] As shown in FIG. 5, exterior insulating member 5100 is disposed vertically against and fixedly attached to the exterior of the building. In the preferred embodiment, exterior insulating member 5100 extends from just above the upper surface of the slab to contact horizontally disposed footer insulating member 5200. As shown in FIG. 5, the top side of footer insulating member 52 is in abutting, physical contact with exterior insulating member 5100. If contact is not achieved between exterior insulating member 5100 and footer insulating member 5200, any gaps can be filled using known non-rigid insulating materials.

[0092] Referring still to FIG. 5, slab insulation device 5000 further comprises footer insulating member 5200. Footer insulating member 5200 should be of semi-rigid construction. Footer insulating member 5200 is also preferably comprised of an insulating material such as expanded polystyrene, polyisocyanurate, or extruded polystyrene. However, persons of ordinary skill in the arts of building construction or thermal insulation will again appreciate that any convenient insulation material will suffice as long as it meets or can be adapted to meet the configuration of the present invention and any applicable construction regulations.

[0093] Turning to FIG. 6, there is shown a top view of elongate footer insulating member 5200, which is generally cuboid in shape. Footer insulating member 5200 is the second portion of continuous thermal barrier 5000. Footer insulating member 5200 is disposed vertically atop the footer and is disposed between the footer and slab. As building insulation materials are not weight bearing, footer insulating member 5200 further comprises at least one void 5300 extending therethrough between its top and bottom sides. During pouring of the slab, concrete is received into and flows through the at least one void 5300 to serve, once that concrete has cured, as a structural support column for the slab and building upon the footer. In the preferred embodiment, voids 5300 comprise a shape selected from the group consisting of a semi-cylinder as shown, a cylinder, a cuboid, and a polyhedron, and the linear frequency of voids 5300 is about 1 void 5300 per 24 inches. Moreover, each void 5300 preferably has a volume of from about 3 cubic inches to 11 cubic inches.

[0094] As shown in FIG. 6, each void 5300 defines a generally semi-cylindrical shape. However, other geometric void shapes may be used such that a void 5300 defines a polyhedron, a cuboid, a cylinder, or any desired shape. Moreover, while a portion of each void 5300 is shown open to footer insulating member interior edge 5350, it will be understood by those of ordinarily skill in the art of building construction that voids 5300 could be enclosed.

[0095] Any desired number, shape, and size of void 5300 may be used in the present invention. The determination of those parameters is based on the material properties of the slab and footer and the desired weight that the slab is intended to hold. For example, medium grade concrete holds about 4,000 pounds per square inch. As illustrated in FIG. 7, footer insulating member 5200 works in conjunction with vertically and horizontally installed rebar through adjacent concrete footer and slab.

[0096] A prototype of the above described embodiment of the president invention was produced for testing by Home Innovation Research Labs (HIRL), an independent laboratory located at 400 Prince George's Blvd. Upper Marlboro, Md. 20774, to determine the structural safety of using the present invention as described herein. In general, the prototypes tested by HIRL were as described herein and shown in FIGS. 5, 6, and 7 of the present application.

[0097] The voids or cutouts in the footer insulation member of the slab insulation device provide a path for 3-inch diameter cylindrical support piers between the turndown slab and the footer when the concrete slab is poured. The support piers are nominally spaced at 2 feet on center.

[0098] For all test specimens the follow process was used to cast the specimens. The footer section was cast on May 30, 2013 and the slab section was cast the following day to simulate typical production scheduling. No adhesion enhancement was done when casting the cold joint between the footer and the slab portion of the test specimen. Commercial ready-mix concrete specified at 3500 psi (slump<5) was used for both the footer and slab portions. A pencil vibrator was used to assist in filing out the forms. Concrete cylinders were cast and tested by a third-party testing firm. All the test specimens were allowed to cure for 28 days before testing began.

[0099] The support piers need to support not only the dead load and live load of the building, they also need to resist compression load that may result from shear loading on the walls. The worst-case combination of loads is likely to be in a corner. The testing was designed to simulate a worst-case corner construction.

[0100] Three specimens were constructed. Each specimen had a 3 diameter circular support pier supporting a 66 section of a slab turndown. The turndown was 11.25 thick. A #3 rebar was placed vertically in the center of the support pier and contained a 90-degree bend as if it were entering the slab. See, for example, FIG. 11.

[0101] Each test specimen was loaded into Home Innovation Labs's large universal testing machine (UTM). The specimen was loaded through a 3.53.5 square steel plate located where the bottom plate in typical construction would be located. This location placed the load slightly eccentric to the support pier. The compression load was applied at a rate of 0.0525 inches/minute. This rate was determined by testing concrete cylinders per ASTM C39 and using the same rate as appropriate for that test method. The specimen was loaded until failure. In the test, the failure of all three specimens was due to failure of the slab portion of the specimen due to the slightly eccentric loading. The table below shows the results of the compression testing:

TABLE-US-00004 Specimen # Ultimate Load (pounds) 1 53565 2 56312 3 51571 Mean 53816 Standard Deviation 2380

[0102] For the three shear test specimens that were prepared, a 4-foot-long footer section 10 wide by 16 deep was formed and cast with one #3 rebar protruding upward where the center of each support pier would be cast as part of the slab. See, for example, FIG. 12.

[0103] After curing for one day, the thermal barricade foam insulation was placed on top of the footer section 2.5 from the end of the footer. The test specimen contained two support piers spaced 2 feet apart with the first pier centered 6 from the end of the footer. A turned down slab section that began 4 from the end of the footer measuring 6 wide by 44 long by 11.25 deep was cast on top of the thermal barricade. Two #4 rebars were placed horizontally through the turned down section and zip tied to the vertical #3 rebars protruding from the footer.

[0104] A piece of 26 nominal lumber was glued to each side of the footer and were used as lifting points to transfer the specimen in and out of the test setup. The lumber was not intended to be part of the test nor was it part of the thermal barricade system. Each test specimen was mounted in Home Innovation's shear wall test apparatus. A typical ASTM E72 test set up was used. Per ASTM E72 a hold down structure was used to limit uplift as the shear load was applied.

[0105] The shear load was applied via a 56 steel plate placed on the end of the slab section. This set up was designed to cause failure at the support piers. The load was applied at a rate of 0.1 inches/minute. Each specimen was instrumented to record slip and uplift. In order to better observe the failure mode as it occurred, the foam thermal barricade was removed from the third specimen prior to testing.

[0106] The shear testing resulted in an initial failure of the support pier followed by bending and yielding of the rebar as the displacement continued. The table below summarizes the results of the shear testing at the initial failure of the support pier.

TABLE-US-00005 Displacement at Load at initial failure initial failure Specimen # (pounds) (inches) 1 4100 0 (see discussion) 2 8832 0 3 10467 0 Mean 7800 0 Standard Deviation 3307 0

[0107] Referring again to FIG. 5, there is shown an internal insulating member 5400. Internal insulating member 5400 generally comprises a rectangular or cuboid shape of any desired width, length, and height for use during home construction. Internal insulating member 5400 is also preferably comprised of an insulating material such as expanded polystyrene, polyisocyanurate, or extruded polystyrene. However, persons of ordinary skill in the arts of building construction or thermal insulation will again appreciate that any convenient insulation material will suffice as long as it meets or can be adapted to meet the configuration of the present invention and any applicable construction regulations.

[0108] As shown in FIG. 5, internal insulating member 5400 is disposed between the house side of the footer and the ground. Internal insulating member 5400 extends vertically such that it contacts the interior edge(s) 5350 of footer insulating member 5200. Internal insulating member 5400 preferably further extends vertically to at or near the bottom horizontal surface of the slab.

[0109] Again, as shown in FIG. 5, internal insulating member 5400 should contact the interior edge(s) 5350 of footer insulating member 5200 of thermal barrier 5000. If, during construction, these members do not fully contact, insulating foam may be used to help achieve a contiguous barrier between the perimeter of the slab and ambient conditions.

[0110] Of course, those of skill in the art will appreciate that each of the components of slab insulating device 5000 may be used independently if desired.

[0111] Referring now to FIG. 8, there is shown a top view of an embodiment of a footer insulating member 6000 according to a third embodiment of the present invention. As illustrated in FIG. 8, footer insulating member 6000 comprises at least one long wall insulating section 6100. Footer insulating member 6000 may further comprise at least one corner insulating sections 6200.

[0112] Referring now to FIG. 9, there is shown a top view of wall section 6100 of footer insulation member 6000 according to the embodiment of the present invention that is shown in FIG. 8. As illustrated in FIG. 9, wall section 6100 of footer insulating member 6000 comprises a plurality of cut-outs/voids 6110 through which concrete can flow when a slab is poured over footer insulating member 6000 as described in more detail above.

[0113] Referring now to FIG. 10, there is shown a top view of a corner section 6200 of footer insulation member 6000 according to the embodiment of the present invention that is shown in FIG. 8. As illustrated in FIG. 10, corner section 6200 of footer insulating member 6000 comprises a generally cuboid shape having a central bore 6210 through which concrete can flow when a slab is poured over footer insulating member 6000 as described in more detail above.

[0114] The above-described embodiments are merely exemplary illustrations set forth for a clear understanding of the principles of the invention. Many variations, combinations, modifications, or equivalents may be substituted for elements thereof without departing from the scope of the invention. It should be understood, therefore, that the above description is of an exemplary embodiment of the invention and included for illustrative purposes only. The description of the exemplary embodiment is not meant to be limiting of the invention. A person of ordinary skill in the field of the invention or the relevant technical art will understand that variations of the invention are included within the scope of the claims.