US20080022608A1

US20080022608A1 - System and method for modular construction of a dome structure and assembly components for facilitating same

Info

Publication number: US20080022608A1
Application number: US11/496,299
Authority: US
Inventors: Salah Eldeib
Original assignee: Altus Engineering Ltd
Current assignee: Altus Engineering Ltd
Priority date: 2006-07-31
Filing date: 2006-07-31
Publication date: 2008-01-31
Also published as: WO2008014587A1; CA2592838A1

Abstract

A system and method for creating a dome structure. The method comprises forming a plurality of sections, each section include a top shoulder plate, a bottom shoulder plate, and a plurality of ribs disposed therebetween. The ribs and shoulder plates have an arc-shaped cross-section. The method further includes placing at least two of the sections adjacent to one another to produce a first ring. Respective top shoulder plates, ribs and bottom shoulder plates are secured together. At least two of the sections are placed adjacent to one another to produce a second ring. The second ring is placed on top of the first ring, the second ring having a cross-sectional area smaller than a cross-sectional area of the first ring.

Description

BACKGROUND OF THE INVENTION

The invention relates to a system and method for creating a dome structure and, more particularly, to a system and method enabling a simple, modular manufacture of a dome.
Dome structures, used for centuries by humankind, are noted for their strength and stability as a result of double arch configurations that carry and resist loading in various directions. Wooden domes are highly earthquake and hurricane resistant, as dome shapes resist movement damage better than conventional buildings and wood structures are more flexible than concrete. Domes also provide unique aesthetics inside and out, rich acoustics inside and considerable design flexibility.
During the past 50 years, dome construction has largely taken the form of monolithic concrete structures or wooden geodesic structures, both of which have inherent drawbacks. A monolithic structure (such as concrete domes) generally needs to be created completely on site. Due to the size and weight of such structures, transportation maybe difficult if not impossible. Moreover, in most cases there is little flexibility in design that is often limited in its size or configuration and it may take a long time to actually manufacture the structure. Concrete is not ecologically friendly. Geodesic structures produce an appearance that is multi-faceted that cause potential roof leakage. It is also less aesthetically pleasing than monolithic structures.
Thus, there is a need in the art for a system and method for producing an aesthetically pleasing dome structure which can be easily manufactured, is resistant to weather and is environmentally friendly. There is also a need for a system that can be shipped easily to different site location and easily and quickly assembled on site to provide versatile structures that meets the various needs.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a method and system that enables construction of dome-shaped structures rapidly, easily, and inexpensively.
Another object of the invention is realized in a method and system which involves the creation of a dome structure including by forming a plurality of sections, each section including top and bottom plate structures comprising top and bottom plates, two top shoulder plates, two bottom shoulder plates, and a plurality of ribs disposed therebetween, the ribs and all plates having an arc-shaped, cross-section. The respective top and bottom plates, top shoulder plates, ribs and bottom shoulder plates are secured together and two of the sections or more are placed adjacent to one another to produce a first ring. This is based on the size of sections manufactured. The sections can be manufactured with any sizes to suit the needs, taking into consideration the transportation and the site assembly requirements. A second ring is formed atop the first ring by placing a number of sections adjacent to one another to produce the second ring atop the first ring, with the second ring having a cross-sectional area smaller than the cross-sectional area of the first ring. This could be different for an outward bulging dome shape. The height of rings is variable, as is the length of the sections.
Preferably, the dome sections are made of wood, although the use of other materials is feasible. In accordance with various embodiments of the invention, there may be seven ribs disposed between the top and bottom shoulder plates. The ribs in the second ring may be placed closer to one another than the ribs in the first ring. In general ribs are spaced at specific distance at the bottom of each section. This is determined by the designer. The most common spacing is 16 inches on center. The ribs may be spaced closer on the top of each section than the bottom. Also, while the rib spacing at the bottom is generally the same throughout the sections (the entire dome), the spacing at the top of the section gets smaller the higher the location of the section on the dome. This provides the required dome shape or configuration. This is the other way around in case of an outward dome shape or the inside of a donut shaped structure. Strapping and sheeting may be provided to the exterior of the rings to provide a finished look. Preferably, the strapping is applied on the exterior in one or several layers and on the inside in one layer. Insulation may be disposed in the interior of the rings to obtain a more insulated construction and the sub-components of the section may be secured to one another using tongue and groove fastening mechanisms or other mechanical means.
The invention includes the provision of an assembly machine which can be used to produce the individual sections. The assembly machine may include a plurality of adjustable arms that enable the length of the ribs (the height of the section) to be accommodated.
Each rib holder is rotatable with respect to a base portion about a first axis. Each rib holder includes an arm whose angle is adjustable with respect to a base portion so as to be rotatable about a second axis perpendicular to the first axis. Each rib holder further includes gripping members effective to hold the rib therein, in a manner whereby a plurality of sections of different members of ribs and spacing between ribs may be produced easily using the assembly machine.
The machine preferably has an odd number of arms, for example, 5, 7, 9, etc., that varies, but typically accommodates seven ribs. Each arm has a base that moves on a specific calculated arc track on the table. This is true for all arms except the middle one that is fixed in place. The base of the arms move on these tracks to form an arc that is required in manufacturing the desired sections. All arms rotate on their bases typically from 0 to 90 degrees around an axis that is perpendicular to the track that the base moves on. This axis touches an inner lower point of the section produced, i.e., the arm rotates around the inner point of the bottom shoulder plate. On each arm there are two movable angled sockets that are adjustable to provide the height of section (the length of the rib). Once the number of the desired section is produced, the machine is readjusted to produce the other sections. Again, this is done by moving the bases of the arms on the tracks on the table to produce the desired arc, then rotating the arm on the base to the desired angle and adjusting arm to the required length (in general the height of the sections is the same throughout the dome structure so there is no need to readjust). At this point the shoulder plates and the ribs are placed in place and nailed or stapled together.
The assembly machine can be used at a factory site and the individual dome sections shipped to a construction site. Alternatively, the assembly machine can be utilized directly at a construction site. Several assembly machines may be utilized for one or several different dome constructions, with different machines designed to provide sections of different numbers of ribs, for example, a first machine for seven ribs, a second nine and a third for handling eleven ribs, and so on.
The method for creating a dome structure comprises forming a plurality of sections, each section including top plate structure, a bottom plate structure, and a plurality of ribs disposed therebetween, the ribs and plate structure having an arc-shaped cross-section; securing together respective top plate structures, ribs and bottom plate structures; placing at least two of the sections adjacent to one another to produce a first ring; placing at least two of the sections adjacent to one another to produce a second ring; and sections of the second ring becoming located on top of the first ring, the second ring having a cross-sectional area smaller than a cross-sectional area of the first ring. The second, third, fourth, etc., rings can be optionally fully assembled rings and then placed atop the previous ring or they can be formed in sections and then placed atop a lower ring or actually assembled on top of the lower ring. The entire ring or the entire dome can be produced in one piece.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a dome in accordance with an embodiment of the invention.

FIG. 2 is a front view of a section used to produce a dome in accordance with an embodiment of the invention.

FIG. 3 is a perspective view of a section used to produce a dome in accordance with an embodiment of the invention.

FIG. 4 is a side cut-away view of a portion of a section used to produce a dome in accordance with an embodiment of the invention.

FIG. 5 is a top view of a shoulder plate used to produce a section in accordance with an embodiment of the invention.

FIG. 6 is a side cut-away view of a first ring implanted into the ground to produce a dome in accordance with an embodiment of the invention.

FIG. 7 is two perspective views of an assembly machine for assembling a dome in accordance with an embodiment of the invention.

FIG. 8 is four perspective views of an assembly machine for assembling a dome in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, there is shown a dome 50 which may be constructed in accordance with an embodiment of the invention. Dome 50 is comprised of a plurality of sections 52. Sections 52 are installed in the ground 54 and disposed adjacent to one another so as to form a ring 56 having a substantially circular or elliptical cross-section when viewed from above in the direction of arrow 51. Rings 56 having successively smaller cross-sections are stacked on one another to form dome 50. Seven rings 56 a, 56 b, 56 c, 56 d, 56 e, 56 f, 56 g are shown in the figure. A space may be defined by each ring 56 so as to create an opening, such as opening 58. Opening 58 may be used for a window or door or the like.
Referring to FIGS. 2, 3, 4 and 5, there are shown a plurality of views of section 52. Each section 52 is comprised of an odd number (5, 7, 9, etc.) of ribs 60. Ribs 60 extend vertically when used in a dome 50 and are comprised of studs—such as 2 inches by 4 inches wood studs. Each rib 60 may be, for example, 21 inches by 3 inches by 2 inches. Each section 52 may include the same number, for example seven, ribs. The center to center distance between ribs 60 at a bottom most ring 56 may be 16 inches. This produces smaller distances at the top of the section and the top distances gets less and less the higher the ring or the section is located on the dome even though the spacing of the ribs through out the entire dome structure at the bottom of the sections or rings may be the same. This change in width helps form the dome shape. The shoulder plate dimensions may be 2″ to 5″ deep and ⅜″ thick. For example, if the bottom length of a section is 9′ and the top length of this section is 8′, another section that is located above this section will have a top length under 8′ when the bottom length is 9′. And so on. Ribs may change in size, but need not.
An upper shoulder plate 62 and lower shoulder plate 64 are attached to ribs 60 at top and bottom portions respectively. As shown most clearly in FIGS. 3 and 5, shoulder plates 62, 64 have an arc-shaped cross-section when viewed from the top or bottom. As shown most clearly in FIG. 4, each shoulder plate 62, 64, has a U-shaped cross-section when viewed from the side. The U-shape defines a groove effective to receive a tongue 66 of a respective rib 60. Clearly other fastening structures aside from tongue and groove may be used to combine shoulder plates 62, 64 with respective ribs 60. The walls of the U-shape may be ⅜″ in width and made of OSB (oriented strand board) sheets. Each rib 60 also generally has (but need not have) an arc-shape cross section, and the distal ends of the ribs preferably have angled cuts so that a top-most part of a rib is bent more inwardly toward a center of dome 50 than a bottom-most portion of the rib. As shown in FIG. 3, at a corner of each section 52, a solid blocking stiffener 67 may be used to enhance structural integrity. Stiffener 67 may be 2¼″×2″×6″.
A plurality of sections are disposed adjacent to one another and ribs from adjacent sections are fastened together using, for example, OSB sheathing and fasteners, so as to form ring 56. Referring to FIG. 6, there is shown a side cut-away view of a first ring 56, R1 installed into the ground 54. As shown, ½″ anchor bolts may be used to anchor bottom shoulder plate 64 of the first section 52 of first ring 56, R1 into ground 54. As shown in FIG. 1, a diameter of each ring 56 is smaller than the diameter of a ring vertically beneath it. Rings are connected to one another through the use of OSB strapping boards and fasteners. Once dome 50 is assembled using sections 52, OSB may be placed as a shell outside dome 50. Insulation may also be placed inside dome 50 as desired. A mesh or stucco finish or other siding materials may be placed outside the sheathing. Inside the dome, stucco or drywall may be used.
As can be discerned, dome 50 yields a modular construction. Sections 52 may be designed and constructed at a first location and shipped to a second location before being assembled. The assembly is simply performed by laying out a series of sections 52 and fastening them together to form rings.
Referring to FIGS. 7 and 8, there are shown various views of an assembly machine 80 which may be used to produce a section 52 in accordance with an embodiment of the invention. As shown, assembly machine 80 includes a plurality (e.g., 7) of rib holders 82 so that a distance between ribs in a section may be adjusted. Each rib holder 82 is rotatable with respect to a base portion 84 about a first axis. Each rib holder 82 includes an arm 88 whose angle is adjustable with respect to base portion so as to be rotatable about a second axis perpendicular to the first axis. Each rib holder 82 further includes gripping members 86 effective to hold a rib 60 therein. In this way, a plurality of sections of differing numbers of ribs 60 and spacing between ribs 60 may be produced using assembly machine 80.
A dome construction system in accordance with the invention is unique in that it yields monolithic dome structures built with conventional building construction components, in sections that can easily be assembled on site. The unique structure provides a real dome atmosphere, contrary to the many-faceted geodesic dome structures of the prior art. These wooden building systems that take the shape of domes may use small pieces of waste lumber (e.g., under 14″ long).
These structures have many advantages in addition to their strength and flexibility. They are economical, energy efficient and environmentally sensitive. Each system may be one dome or a number of domes conjoined in any desired fashion, and can be one or multiple story structures. Built in sections for delivery to construction sites, the system can be applied to produce domes of any shape and size up to 1,000 feet in diameter and can be used for residential and commercial buildings, industrial and public structures, arenas and stadiums, and emergency and temporary shelters. For domes greater than 80′ in diameter the system is enhanced by intersecting arches on the inside (similar to the waffle concrete slab in a way). This is done on site and by using standard lumber.
The dome's light and flexible body makes them virtually earthquake proof and suitable for all regions regardless of snow load, wind and earthquake conditions. Paradoxically, the lighter the building, the better the results in earthquake and hurricane tests. A wooden dome in accordance with the invention is much lighter than concrete domes. The structure's life span is expected to be more than twice that of conventional wood structures, thereby causing less ecological damage as the environmental impacts of these buildings are spread over a longer period.
Construction time is greatly reduced—depending on size, the system takes as little as one to two days to assemble for medium size structures. In addition, since job site disturbance is minimal and environmental impacts of construction waste disposal are minimized, the system is suitable for environmentally sensitive areas. The domes are a value-added dream. They can use sawmill trim ends 14 inches long and smaller, so the construction system is highly ecologically friendly. Waste generated by seven dome buildings equals that of one conventional building.
The system is energy efficient (providing heating and lighting savings of 30-50%); flexible (with clear spans and no required interior support, space can be altered easily to accommodate future layout changes); and provides superior design aesthetics (with open spaces, better air circulation and improved light distribution). Domes are fine for homes and small buildings. Almost anything can be done architecturally. Shapes could be elliptical, dome shaped or oval, and can even be constructed on top of rectangular or square foundations. Clear spans are possible to very large diameters and the structures can have any number of openings.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

Claims

1. A method for creating a dome structure, the method comprising:

forming a plurality of sections, each section including a top plate structure, a bottom plate structure, and a plurality of ribs disposed therebetween, the ribs and plate structures having arc-shaped cross-sections;

placing at least two of the sections adjacent to one another to produce a first ring; and

placing at least two of the sections adjacent to one another to produce a second ring having a cross-sectional area smaller than a cross-sectional area of the first ring; and

locating the second ring on top of the first ring, and using a sufficient number of rings to produce the dome structure.

2. The method as recited in claim 1, wherein the top plate structure is constructed so as to include a top plate and at least one top shoulder plate and the bottom plate structure includes a bottom plate and at least one bottom shoulder plate.

3. The method as recited in claim 2, wherein the sections are made of wood.

4. The method as recited in claim 2, including assembling seven ribs between the top and bottom shoulder plates.

5. The method as recited in claim 2, wherein the ribs at the top of the second ring are placed closer to one another than the ribs at the top of the first ring, while the spacing at the bottom is the same for the first and second sections.

6. The method as recited in claim 2, further comprising applying strapping and sheathing to an exterior of the rings.

7. The method as recited in claim 2, further comprising applying an insulation to an interior of the rings.

8. The method as recited in claim 2, including providing two top shoulder plates and two bottom shoulder plates.

9. The method as recited in claim 2, including securing the second ring to the first ring.

10. The method as recited in claim 2, including providing fewer ribs in the second ring than in the first ring.

11. The method as recited in claim 2, including affixing adjacent sections to one another.

12. The method of claim 6, including applying strapping at the interior of the dome structure.

13. The method of claim 1, including physically securing the sections and rings together.

14. A building dome, comprising:

a first ring, the first ring including at least two sections disposed horizontally adjacent one another;

a second ring disposed on the first ring, the second ring including at least two sections disposed horizontally adjacent to one another, the second ring having a cross-sectional area smaller than a cross-sectional area of the first ring; and

each section includes a top plate structure, a bottom plate structure, and a plurality of ribs disposed therebetween, the ribs and plate structures having an arc-shaped cross-section, wherein respective top plate structures, ribs and bottom plate structures are secured together.

15. The building dome of claim 14, wherein the top plate structure includes a top plate and at least one shoulder plate and the bottom plate structure includes a bottom plate and at least one shoulder plate.

16. The building dome of claim 15, wherein the plate structures are constructed of a material selected from the group of materials consisting of: synthetic materials, natural materials, OSB, wood, hemp, metal, sugarcane fiber, and bamboo.

17. The building dome of claim 15, wherein the sections are constructed of a material selected from the group of materials consisting of: synthetic materials, natural materials, OSB, wood, hemp, metal, sugarcane fiber, and bamboo.

18. The building dome of claim 15, wherein there are seven ribs disposed between the top and bottom shoulder plates.

19. The building dome of claim 15, wherein top ends of the ribs of the second ring are placed closer to one another than in the first ring, while the rib spacing at the bottom of the first and second rings is substantially the same.

20. The building dome of claim 15, further including strapping and sheathing applied to an exterior of the rings.

21. The building dome of claim 15, wherein the second ring is physically secured to the first ring, and wherein adjacent sections are physically affixed to one another.