US 3254459 A
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Description (OCR text may contain errors)
June 7, 1966 R. w. BoDLx-:Y
Dom: coNsTRUcTIoN Filed Dc. zo. 1981 3,254,459 DOME CONSTRUCTION Robert W. Bodley, Highland, Ind., assignor to Union Tank Car Company, Chicago, Ill., a corporation of New Jersey Filed Dec. 20, 1961, Ser. No. 160,759 1 Clairn. (Cl. 52-81) It is another object to provide a new and improved self-.
supporting dome construction.
It is still another object to provide a dome construction incorporating a self-supporting'lattice structure upon which is superimposed a covering panel structure composed of panel units which are supported by and coact with the lattice structure and with each other to form an imperforate surface on the dome. v
It is yet another object to provide a panel structure of the aforedescribed character comprising panel units which are readily adaptable to on-the-job modification for complementary coaction with the lattice structure.
` It is yet a further object to provide a dome construction which is substantially more simple to erect than generally similardome constructions presen'tly utilized.
It is another object to provide a dome construction which requires less time and manpower to erect and is correspondingly less expensive than the aforedescribed generally similar dome constructions.
It is still another object to provide a dome construction including a panelled surface which is free of pockets and facilitates simple upkeep and maintenance. v i
The above and other objects are realized in accordance with the present invention by providing a new and improved self-supporting dome construction. The invention contemplates a lattice structure composed of struts which are interconnected in a repetitive pattern to form a self-supporting framework, and a componentized panel structure which overlies the framework in uniquely adaptable relationship. Individual panel units which comprise the panel structurecomponents are constructed so that they can readily be modified on-the-job to accommodate variations in the repetitive pattern of the supporting framework. The panel units extend into immediately adjoining relationship across the entire expanse of the lattice structure'and are inter-connected to establish an imperforate dome surface.
The panel units which make up the dome panel structure and the individual struts and joint components which make up the lattice structure are susceptible to mass production. In this light, assembly of the dome structure in the field is fast and inexpensive.
The invention, both as to its organization and method of operation taken with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, in which:
FIGURE 1 is a schematic perspective view of a geodesic dome construction embodying the features of the present invention; i
FIGURE 2 is an enlarged fragmentary view, displaced 90 degrees, of the dome construction of FIGURE 1;
FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 2;
FIGURE 4 is a fragmentary plan view of a lattice joint assembly embodied in the dome construction of FIG- URE l;
United States Patent ICC FIGURE 5 is a sectional view taken along 5-5 of FIGURE 4; and
FIGURE 6 is a greatly enlarged plan view of a portion of the dome construction embodying the features of the present invention, as illustrated in FIGURE 2.
Referring now to the drawing and particularly to FIG- URE 1, a geodesic dome construction embodying the features of the present invention is illustrated and identified generally by reference numeral 10. The geodesic spherical configuration of the dome 10 is merely illustrative of one of many different shapes that might be embodied in a dome construction built in accordance with the present invention, however. For example, a lamellar Vspherical dome might incorporate the features of this invention. On the other hand, a dome construction embodying the features of this invention might take the form of a paraboloid, or an ellipsoid, or a conic or cylindrical configuration. Consequently, it should be understood that the description of the invention in terms of a geodesic dome is merely exemplary.
With specific regard to the geodesic dome construction illustrated in FIGURES 1 and 2, it incorporates a lattice framework 14 which supports and is joined to a uniquely constructed dome panel structure 15. The lattice framework 14 is self-supporting and comprises two sets of substantially identical components which can be assembled in the field with a minirnum of manpower, time, and expense. The panel structure 15 forms an imperforate surface on the dome 10 and is assembled in the field from substantially identical components. These components are readily modified on-the-job to insure complementary coaction with the lattice framework.
The lattice framework 14 comprises a plurality of subi preferably rectangular or square in cross-sectional configuration, as best seen in FIGURE 3. The' upper surface 25 of each strut 20 is fiat and of substantial width in order that the panel structure 15 might be supported and i joined with the struts along the surfaces 25. Although the use of struts 20 having rectangular or square crosssectional 'configurations is preferable, however, it should be understood that they might have other cross-sectional forms. Regardless of the configuraton of the struts 20 though, the upper surface should be flattened to facilitate ease of attachment to the panel structure 15.
Referring now to FIGURES 4 and 5, one end of a strut 20 is shown secured to a corresponding cap 21 through a transversely extending bracket 30 which is seated in a corresponding recess 31 formed in the upper surface of the end of the strut. The bracket 30 is preferably welded in the recess 31 and is apertured adjacent its opposite ends, as -at 32, to receive conventional nut and bolt fasteners 33 which extend through corresponding apertures 34 in the cap 21 and secure the end of the strut 20 to the corresponding cap 21. As will be seen in FIGURE 5, the recess 31 is just of suficient depth to receive the bracket 30 and the cap 21 with the upper surface of the cap 211 in substantially flush relationship with the upper surface 25 of the strut 20.`
The caps 21 are preferably formed of 'aluminum plate and are dome-like in configuration. As seen in FIGURE 2, each cap 21 has six struts 20 secured to its periphery and extending radially outwardly therefrom to be connected to other caps 21 in the same manner. Although six struts 20' are shown and descri'bed in relation to each aaa-1,459
cap 21, however, it should be understood that the number might vary at certain points in the lattice framework 14. Because of thev dome-like configuration of each cap 2.1 (see FIGURE 5) and the tangential relationship of the upper surface 25 of the struts 20 with the curve of the upper surface of the caps 21, the dome acquires its generally spherical configuration. In the alternative, however, the joint caps 21 might form shallow cones and achieve the same effect.
The lattice framework 14 can readily be assembled in the field, as has previously been pointed out, by a fe'w men without Welding equipment or the like. The framework is self-supporting and, as will be recognized, the struts 20 are so arranged that they lie along great circles of the spherical dome 10. This is a characteristic of the geodesic construction which the dome 10 incorporates. -As has been pointed out, however, various other dome constructions and configurations might embody the features of the present invention.
In its yassembled form, the lattice framework 14 is entirely self-supporting and resembles a large semispherical cage having a repetitive lattice work pattern of triangles, seen generally at 45 in FIGUR'E 2. These triangles 45, formed by the struts 20 joined at their opposite ends by corresponding joint caps 21, are theoretically of an exactly prescribed design configuration. I-Iowever, due to various infiuences, including elastic deformation of the lattice framework 14 and slight irregularities in the length of the prefabricated struts 20, for example, it is not unusual for the various triangles 45 throughout the dome to vary somewhat from their design configuration.
The panel units 40 which make up the componentized dome panel structure 15 readily lend themselves to modification in the field to conform to variations in configuration of prescribed triangles 45 in the framework 14. Each panel unit 40 is identical in construction and gener'ally similar in configuration. It is adapted to be joined to the struts and joint caps 21 which make up a corresponding triangle 45 in the lattice framework 14. In addition, each panel unit 40 is joined to each other to establish an imperforate relationship over the expanse of the dome 10.
Referring specifically to FIGURE 2, each panel unit 40 is shaped like a hollow tetrahedron which is formed of three panels, 41, 42, and 43, joined together by any conventional means. The panels 41-43 are preferably comprised of aluminum sheets which are welded together to form a panel unit. The panel unit is anodized to enhance the beauty of the dome 10 .and provides it with a corrosion resistant surface.
Referring now to FIGURE 3, the free edge of each of the panels 41-43 is bent upwardly to form a flange 47 which lies substantially in the plane of the imaginary base of the tetrahedron. The fianges 47 are joined together at their opposite ends by Welding to form a continuous flange around each panel unit. This is made possible by leaving extended ears (not shown) on the aluminum panels 41-43 at the opposite ends of each prospective flange 47 when the panels are formed. This continuous flange overlies the upper surface 25 of corresponding struts 20 in flush relationship. In the same manner, the fiange 47 overlies the joint caps 21 to which the opposite ends of the struts 20 in question are bolted. In this relationship, the flange is welded to corresponding struts 20 and joint caps 21.
As has previously been pointed out, however, the configuration of each triangle 45 formed by three struts 20 is frequently inconsistent to some slight degree with the design specifications. Consequently, the fianges 47 surrounding the panel unit 40 are purposely constructed so as to have substantial width. The width of the fianges 47 then permits the confirguration of the various triangles to vary somewhat without developing a gap between the free edge -of a flange 47 and a corresponding strut 20.
(j. On the other hand, the fianges 47 can readily be trimmed down -on-the-job to fit up with adjoining panel units 40 when the angle between the adjacent legs of a triangle 45 is slightly less than anticipated, for example.
When the panel units are properly fitted in overlapping relationship with corresponding struts 20, the corners 50 of each panel unit extend into immediately adjoining relationship over a corresponding joint cap 21, as seen in FIGURE 6. It will be understood, of course, that normally six of these corners 50 meet in immediately adjoining relationship on each joint cap. In this manner, they cover the joint cap 21 in question.
When the panel units 40 are properly fitted in overlapping relationship with corresponding struts 20, the corners 50 of the panel units extend into immediately adjoining relationship over corresponding joint caps 21, as seen in detail in FIGURE 6. As pointed out, normally six of these corners 50 meet over each joint cap 21. In this relationship, the panels 40 are welded to corresponding struts 20 and joint caps 21. Each panel unit 40 is then rigidly interconnected with the twelve panel units which surround it. As a result, the strength of the panel structure 15 is substantially enhanced and the overall load carrying capacity of the dome 10 correspondingly increased.
Welding the panel units 40 to corresponding struts 20 and joint caps 21 tends to destroy the anodized coating on the fianges 47 surrounding the panel units 40. In addition, as has been pointed out, the caps 21 and the struts 20 and not anodized in the first place, to facilitate Welding the panel units thereto. Accordingly, the dome 10 is susceptible to corrosion along the welds formed over the struts 20 and the caps 21.
To cover these welds and the fianges 47 and enhance the beauty of the dome surface as well as negate the corrosive effect of the elements on un-anodized surfaces, sealing strips 51, preferably formed of very thin anodizcd aluminum sheet are cemented over the fianges 47, as seen in FIGURES 3 and 6. The strips 51 are preferably secured with a highly moisture-resistant cement of any well known composition, such as a rubber Thiokol cement, for example. The ends of each strip 51 meeting over a corresponding joint cap 21 might overlap or, in the alternative, they might be trimmed to complement each other in adjoining relationship, as seen in FIGURE 6. On the other hand, some of the strips might overlap while others are trimmed to complement each other.
From the foregoing description it will be appreciated that a dome 10 has been described which can readily be constructed in geodesic, lamellar or other spherical shapes, or in the alternative, in one of the various non-spherical configurations such as a paraboloid, for example. Regardless of the configuration of the dome itself, its construction facilitates simple and expeditious assembly in the field from a minimum number of mass-produced, substantially identical component parts.
The lattice framework 14 on the dome 10 is an entirely bolted construction eliminating laborious Welding procedure normally required in assembling a framework of this nature. In this light, the framework 14 is completely self-supporting, not relying upon the panel structure 15 to carry any load. In practice, however, the panel structure 15 does carry a certain amount of the load, since a slight plastic deformation of the dome 10 under a load of snow, for example, brings load to bear on the skin. Since the panel units 40 are all connected to each other and to the struts 20, this provides the dome with considerable additional strength to resist deformation.
The panel structure 15 is comprised of component panel units 40 which can readily be trimmed or otherwise altered in the field to exactly overlap corresponding struts 20 and the joint caps 21 which interconnect them. In this light, of course, the panel units 40 extend into immediately adjoining relationship over the cap 21 as weil as over the struts 20. This relationship facilitates joinder, by sealing strips 51, of the entire extent of the adjacent edges of panel units 40, once they have been secured to the struts 2'0 and the caps 21. The dome panel structure 15 which is formed is imperforate over its entire surface. In addition, the surface forms no pockets which might retain rain water, for example, :and make the maintenance of the dome surface (painting) for example, difficult.
While an embodiment described herein is at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claim all such modifications :and improvements as fall within the true spirit and scope of the invention.
What is desired to be clairned and secured by Letters Patent of the United States is:
A self-supporting dome construction, comprising: a plurality of aluminum struts arranged in a repetitive pattern of triangles, each of said struts having 'a flat upper surface, joint members in the form of aluminum caps interconnecting adjoining ends of said struts, each of said caps having an upper surface flush with corresponding flat upper surfac es on correspondng struts, said strut ends being recessed to receive corresponding caps, and panel units overlying said triangles, each of said panels joined to form a pyramidal panel unit structure, an outwardly turned flange.
References Cited by the Examiner UNITED STATES PATENTS 2,610,593 9/ 1952 Wasserman 52-80 2,9l8,992 12/1959 Gelsavage 52-81 2,978,074 4/1961 Schmidt 52-81 RICHARD W. COOKE, I R., Primary Examiner.