US2869693A - Reticular structure - Google Patents

Description

D. WQOD RETICULAR STRUCTURE Jan. 20, 1959 Filed April 24, 1958 INVENTOR. DONALD wooo A 1 o R Jan. 20, 1959 D. WOOD RETICULAR STRUCTURE 4 Sheets-Sheet 2 Filed April 24, 1958 w OE INVENTOR. DONALD WOOD Max/f ATTORN/Zf Jan. 20, 1959 00 7 2,869,693

United States RETICULAR STRUCTURE Donald Wood, New York, N. $1., assignor to Hill Cross Company, Inc., New York, N. Y., a corporation of New York Application April 24, 1958, Serial No. 739,675

9 Claims. (Cl. 139-34 7 The present invention relates to structural framework, and more particularly to a novel and improved reticular structure characterized by high strength in relation to its weight.

The structure of the present invention is intended primarily for, but is not necessarily restricted to, use as a light-weight, high strength filler, and is similar in this respect to conventional honeycomb structures, for example. The new structure represents a substantial improvement, however, in that it may be constructed to extend without limit in any direction without strength loss. By way of contrast, a conventional honeycomb structure, for example, loses strength as its depth increases, unless laminating panels are interposed periodically, in which event there are planes of weakness in shear.

In general, the improved structure comprises a plurality of rectilinear structural elements arranged to form structural modules of a novel and improved type, and, in the complete structure, the modules are interconnected in a manner such that each module forms part of several other modules. The overall structure has characteristics resembling those of a crystalline material but, of course, is formed of rectilinear elements rather than solid crystal bodies.

As one of its important features, the structure of the invention incorporates novel modular structural units, each compnsed of a pair of tripod structures arranged base to base and interconnected by a generally hexagonal base structure. The three legs of one tripod structure are connected to three of the apices of the hexagonal base structure, while the legs of the other tripod structure are connected to the remaining three apices of the base structure, and the arrangement is such that alternate apices of the base structure are connected to legsof alternate onesof the tr.pod structures. Advantageously, all of the several rectilinear elements forming the tripod structures are of equal effective length, as are all the rectilinear elements forming the hexagonal base structure; and the respective lengths of tripod and base elements are so related as to achieve maximum load-carrying strength in the module. As may be desirable or expedient, in particular cases, the rectilinear structural elements may be formed of tubes, rods, wires, structural shapes, etc.

As one of the more specific features of the invention, the improved structure incorporates modular structural units as set forth in the preceding paragraph, in which the generally hexagonal base structure has elements lying in three planes, two of which are generally parallel and are intersected by the third. A pair of spaced, parallel'base elements define the third plane, and pairs of intersecting base elements define the parallel planes. The arrangement is such that the bases of the opposed tripod structures coact with the base structure in a manner imparting maximum strength to the modular structural unit.

Another specific 'feature of the invention resides in the provision of an improved structure of the type and having the characteristics mentioned above, in which novel arrangements are provided for assembling a structural framework from structural parts of standardized form. Advantageously, the standardized structural parts are of two types, and each includes three rectilinear elements from which modules of the framework are formed. One type of standardized part may comprise two tripod elements and one base element, while the other may comprise two base elements and'a tripod element, and the assembly of the standardized parts is such that, in the make-up of a single, complete module, elements of at least some of the parts extend out from the module to form parts of adjacent modules. Accordingly, in a complete structure, the modules are interlocked in a manner providing improved strength. In addition, the standardized parts may be so formed as to provide for the mechanical interlinking of parts at each joint or apex, in a manner such as to avoid shear stresses in welded or soldered joints, for example.

While the new structure may be formed in a variety of ways, using various structural shapes and members to form the various rectilinear elements, a relatively lightduty structure may advantageously be formed of wire or rod, bent to form the standardized parts described in the preceding paragraph and provided with interlocking joints as there described. The new structure, in that form, is adapted for continuous automatic, machine fabrication in a bulk form, suitable for immediate use or for cutting, for example, to sizes and shapes desirable or expedient for particular applicatons.

For a better understanding of the invention, reference should be made to the following detailed description and to the accompanying drawing, in which:

Figs. 1 and 2 are a plan view and a side elevation, respectively, of a typical structural module of the type inccrporated in the new structure;

Fig. 3 is a perspective View of the structural module of Figs. 1 and 2;

Figs. 4 and 5 are perspective views of a partial structure incorporating a plurality of modular units of the type shown in Figs. F3;

Fig. 6 is a perspective view-of a structural module of the type shown in Figs. 1-3, incorporating certain additional features of the invention;

Figs. 7 and 8 are fragmentary plan and elevational views. respectively. of a reticular structure formed of modular units of the type shown in Fig. 6;v

Figs. 9 and 10 are simplified representations of structures incorporating the invention; and

Figs. 11 and 12 are views illustrating the general manner of formin standardized parts used in assembling the structure of Figs. 7 and 8.

Referringnow to the drawing, and initially to Figs. 13 thereof, the reference numeral 10 designates, generally, a structural module formed, in accordance with the invention, of rectilinear elements which may be rods, wires or other suitable structural elements. The module 10 comprises a pair of tripod structures 11, 12, arranged generally base to base, and a base structure 13 connecting the bases of the respective tripods. The tripod structures Ill, 12 are advantageously of substantially identical form, comprising rectilinear structural elements 14-16 and l7--l9 respectively. The elements 14l9 which, for convenient identification, may be referred to as tripod elements, are of equal length, and the elements forming a tripod are joined at an apex 20 or 21, in any suitable manner, such as by welding, soldering, clamping, etc., and the elements of each tripod are disposed at substantially equal angles, each with, respect to the others, to outline a three-sided pyramid of substantially equal sides.

In accordance with one aspect of the invention, the base structure 13 is hexagonal in outline and is comprised of six rectilinear structural elements 22-27 of substantially equal length. The elements 22;-27, which may be referred to as base elements, are joined end to end at apices 28-33, as by soldering, welding, etc., or by suit able connectors. Also in accordance with the invention, the base ends ofthe elements forming one tripod structure are attached to the base structure at first alternate apices of the base, while the elements of the other tripod structure are attached at second alternate apices of the base. Thus, the elements l4-ll6 of the tripod structure ill are attached to apices Z9, 31, 33, while the elements 17-49 of the tripod structure 12' are attached to apices 28, 3t 32. The arrangement is such that the bases of the tripod structures are laterally offset one from the other, as shown in Fig. 2, and the tripod structures are displaced rotationally 180 degrees (or 60 degrees) as indicated in Figs. 1 arid 2.

Advantageously, the elements 2?;27, forming the base structure, define three planes, two of which are generally parallel and the third of which intersects the other two. Thus one plane A, which may be referred to as a primary base plane, is defined by spaced, parallel base elements 22, 25, and spaced, parallel planes B, C, which may be referred to as secondary base planes, are defined by intersecting pairs of base elements 23, 24 and 26, 2.7. The

relationship of the base planes is illustrated in Fig. 2, and it will be observed therein that the secondary planes B, C are inclined at substantially equal, predetermined angles with respect to the primary plane A.

In the illustrated form of the invention, the respective tripod structures 11, 12 have two elements terminating in the primary base plane A and a third element terminating in a secondary plane B or C, and the third element of each tripod structure is attached at an apex 39 or 33 which lies on the same side of the primary base plane as does the tripod structure generally. Thus, the element 14, of the tripod structure 11, which lies above the base plane in Fig. 2, is attached at the apex 33, which also lies above the base plane. provides for improved module strength and for improved strength in a structure incorporating such modules by disposing the various rectilinear elements of the structure in a manner such that internal forces are effective, to a large extent, to place elements in tension.

While it is recognized that the relative proportions of the structural module and its elements may be varied to some extent, depending upon factors such as the intended use of the structure, it has been determined that the length of the tripodelements is advantageously on the order of 1 /2 times the length of the base elements, and the secondary base planes are advantageously indined at angles on the order of 35 with respect to the primary base plane. Calculations indicate, and experience demonstrates, that the specific arrangement thus described is generally characterized by near-maximum strength in relation to weight.

In practice, the structural module of Figs. 1-3 may be incorporated in a reticular structure in the manner shown in Figs. 4 and 5. Thus, Figs. 4 and 5 show a partial structure, comprising three structural modules 3d36 which are interengaged in amanner forming a structure of great strength in relation to its Weight. The modules 34, 35' are arranged side by side and one rectilinear element37 is incorporated in the base structure of both modules, as part of the primary base planes thereof. The module 36 is illustrated asbeingbelow and between the modules 34, 35, and rectilinear elements 38, 39 are inco-rporatedin the base structures of the modules 34, 35, respectively, and in the base structure of the lower module 36, as parts of secondary base planes of the modules. As will be readily apparent from the foregoing, a reticular structure of indefinite size and shape may be formed by adding additional modules to extend the structure in any direction. And, in a complete struc- The described arrangement ture, all the elements forming a module which is surrounded by other modules are incorporated as parts of the surrounding modules.

Referring now to Figs. 68, there is illustrated a structure incorporating modules of the general type before described, but in which standardized, interlocking parts are provided to facilitate manufacture and assembly of the structure and to form joints of high strength. 'Fig. 6 illustrates a single module of the modified structure, and it will be observed that the module, shown in full lines, has the general shape and form of the module of Figs. 1-3. In the modified structure, however, standardized parts of two types, eachforming a plurality of rectilinear structural elements, are utilized in the assembly of a complete structure.

In Fig. 6, the numeral designates generally a part of a first type, which is advantageously formed of wire or rod and is bent to form, in series, a pair of tripod elements 562a, 50b and a base element 50c. In accordance with one aspect of the invention, the part 50 has, at the portions thereof constituting the end of an element, means forming, in the complete assembly, parts of interlocking joints. Thus, at the upper end of the tripod element Sila, the part 5th is provided with an S-shaped bend lying generally in the plane of the elements 5%, 5tib and forming a recess 5% and a hook 50c. In the region of junction between the tripod elements Silt: and 50b there is formed a relatively deep, U-shaped bend, lying generally in a plane normal to the plane of the elements dila, Sill) and forming a recess 50], which opens toward the viewer, in Fig. 6. In the region of junction between the tripod element 5% and the base element Elle-the wire is provided with a U-shaped bend, lying generally in the plane ofthe elements 5a,.5t b and'forming a clownwardly opening recess Stlh and having a locking tab Stlj at its end extremity extending at right angles to the U- shaped bend.

in a complete structure, several parts are utilized which are identical to the part 50 described in the preceding paragraph. Accordingly such identical parts will not be described separately,'bu't will be identified and referred to usin. the reference characters of the foregoing paragraph, preceded by numerals, 1', 2, etc., each to refer to a different part. And, for purposes of clarity, those portions of a structural partwhich do not form'elements of the module illustrated in Fig. 6 are shown in broken lines.

The second of the two types of standardized parts in: corporated in the structure of Fig. 6 is designated by the reference numeral 60, preceded, in the cases of like but different parts, by the numerals 1,, 2, etc., and the part 60 comprises wire or rod bent to form, in series, two base elements 60a, 60b and a tripod element 60c. The base elements 60a, 60b form part of the primary and secondary base planes respectively of one module, and the tripod element 600 forms parts of another module.

At the end of the base element 60a, the wire is provided with an S-shaped bend, forminga recess 66d and a hook etle lying in a generally vertical plane, as viewed in Fig. 6. In the region of junction between the base elements 60a, 6%, the part 60 is provided with a U-shaped bend, lying in a generally vertical plane and forming a recess 60 openingtoward the viewer. In the region of junction between the base element 6% and tripod element 6tlc, there is a U-shaped bend, lying in a generally vertical plane and forming a downwardly opening recess dtlg. And at the end of the tripod element 60c the part is bent to form a downwardly opening recess 60h and a locking tab 60f extending at right angles thereto.

To form a complete module, as shown in Fig. 6, twelve rectilinear structural elements are requiredthat is, six base elements and six tripod elementsand, in the illustrated form of the invention, the necessary elements are provided by the assembly of four of the standardized parts of each type, although additional parts are required to complete all the joints or apices of the assembly. Thus, in the module shown in full lines in Fig. 6, two elements of a first tripod structure and one element of the base structure are formed by the elements 50a, 50b and 500, respectively, of the part 50. The third element of the first tripod structure is formed by the element 26% of a part 260, and the tripod elements are joined at an apex or joint 7t) by the interlocking of the recesses 260g and 50f. Altogether, four parts are locked together at the joint 70, including parts 360 and 750,

illustrated in part in Fig. 6. Thus, the recess 360d and hook 3602, of the part 360, and the recess 75% and lock ing tab 750i are interlocked in the recess 50 And, in this respect, the hook 360:: and locking tab 750 may, where necessary or desirable, be formed following otherwise complete assembly of the joint 70.

In a complete structure, alternate ones of the plurality of joints are identical, and joints corresponding to the joint 70 described in the preceding paragraph are identified by the reference characters 170, 270, etc.

The base structure of the module shown in Fig. 6 includes, in addition. to the element 50c, elements 60a and 60b of the part 6%, element 35% of a part 350, element 160!) of a-part 160, and element 460a of a part 460.

And the second tripod structure of the module comprises element 1600 of the part 160, element 150a of the part 156, and element 65% of a part 650.

The complete module includes joints of a second type, identified by the reference characters 80, 180, 280, etc., by which other elements of the structure are interlocked. Thus, at the joint 80, parts 50, 350 and 560 are received in the recess 160 of the part 160 in a manner to effect the interlocking of the several parts. The order of assembly is such that the recess portion 350g is received in the closed end of the recess 160 after which the recess portions 50d and 564th, of parts 50 and 560 respectively, are received in the recess 160 The book 50c and locking tab 560i may be formed after the joint is otherwise completely assembled, where desirable or expedient.

A complete module, as shown in Fig. 6, has eight joints,

four each of the 70 and -80 type, and some of the joints are completed by parts, such as the part 750, which have no elements in the module shown in full lines but which form elements of other modules of a complete structure.

Figs. 7 and 8 illustrate the manner in which the many parts of a complete structure are interconnected to form a body of indefinite size and shape, comprising a plurality of structural modules mutually interlinked to achieve great strength in relation to weight. Where appropriate, reference characters used in Fig. 6 are applied to Figs. 7 and 8 to designate corresponding parts.

In the structure of Figs. 7 and 8, as well as that of Fig. 6, the several joints 70, etc., 80, etc., may be finished by soldering, Welding, clamping, etc., but it is to be noted that the interlocking parts of the joints are so arranged that forces applied in tension and compression to structural elements are transmitted through the mechanically interlocked parts at the joints and little, if any, of the trans-.

mitted force is applied to place solder or weld connections in shear, for example. This arrangement is especially advantageous in a light-duty, wire structure, for example, since solder may be used to complete-the joints, or, where appropriate, soldering, welding, etc., may be omitted altogether.

In a typical application of the new structure, a body of approximately the desired size and shape is assembled by building modules, in courses or otherwise, to the desired dimensions. In the simplified representation of Fig. 9, for example, modules 8587 form a horizontal course, which may be any number of units in width and length and may have any number of similar courses above and below. And, in this respect, it will be understood that a typical structure will ordinarily comprise several vertical courses, although, for simplicity, the

structure of Fig. 9, as well as that of Fig. 10, is illustratedas having onlya single course.

Where the structure of Fig. 9 is assembled using the standardized parts described in connection with Fig. 6, elements of incomplete modules will project from the peripheral limits of the body, and such elements may be cut off or not, as desired, depending, usually, upon the intended end use of the structure.

A typical use of the structure of Fig. 9 is illustrated in Fig. 10, wherein the body formed by modules 87 is interposed between panels 88, 89 to form a strong, light-weight combination structure. And, in a combination structure of that type, it is frequently satisfactory if elements projecting from the structural body are left attached thereto and pressed flat by the panels 88, 89, substantially as illustrated in Fig. 10. The combination structure of Fig. 10 is, of course, intended to be representative only, since many other uses or applications of the modular structure will suggest themselves to persons skilled in the art.

In the manufacture of the structures illustrated in Figs. 6-8 it is contemplated that the standardized parts -50 and -60 may be formed on a continuous basis by suitable wire forming means, for example, which, as a first operation, may form the several elements and bends in a single plane, substantially as indicated in Figs. 11, 12. Following the initial planar formation steps, the several elements may further be bent, twisted, etc., to the desired final form. The foregoing operations may be performed by more or less conventional wire forming machinery.

Assembly of a structure may, of course, be carried out by hand operations. However, at least for structures of relatively small size, it is contemplated that the manipulative operations for effecting assembly may be performed mechanically, by apparatus acting in conjunction with the wire forming means. In this respect, assembly may be effected by banks of manipulators equal in number to the rows and courses of parts of each type used in forming a body of predetermined cross section, and an assembled body of that cross section is formed progressively, to an indefinite length. The progressively formed body may then be cut to lengths appropriate for a desired end use.

The new structure is advantageous in that its strength, in all directions, is great in relation to its overall weight. The structural modules, of which a structural body is formed, are very rigid and are arranged, when incorporated in a structural body, in such manner that forces are, to a large extent, applied to place elements under tension, to derive the greatest useful strength therefrom. Thus, while the load applied to the structural body as a whole is usually purely compressive, the load supporting forces throughout the body are, to a large extent,

in tension. Accordingly, the individual elements of the structure may be simple, rectilinear elements, suchas wires, rods, etc., which have relatively low strength in compression. It should be understood, however, in this respect, that structural shapes, such as angles, I-beams, tubes, etc., may also be utilized, where appropriate, to provide greater compressive strength.

In the form of the invention illustrated in Figs. 68, further advantages are derived in respect of simplification of assembly, resulting from the use of standardized parts forming a plurality of structural elements, and in respect of improved joint strength, resulting from the provision of mechanically interlocking joints. Either of the foregoing features may be incorporated separately in the new structure, but, in a light-duty structure suitable for automated construction from wire or rod elements, the features may be used in combination to great advantage.

One of the advantageous, practical features of the new structure is that it may be constructed to extend without limit in any direction and that, as no cleavage s planes. (i. e., planes of weakness) are present, strength is not sacrificed when thick or massive structures are assembled. Moreover, an assembled structural body may be cut to any shape and size desired without sacrifice of the superior strength characteristics of the structure.

It will be understood, of course, that the specific forms of the invention herein illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the invention. Accordingly, reference should be made to the .following appended claims, in determining the full scope of the invention.

1 claim:

1. A reticular structure formed of interconnected structural modules, in whicha module comprises a base structure .of generally hexagonal outline, and two tripod structures extending in opposite directions from said base structure, said tripod structures comprising rectilinear tripod elements vjoined at theirouter ends-and engaged at their base ends with alternate apices of 'said base structure, the elements of the respective tripod structures being engaged with different apices of said base structure.

2. The. reticular structure of claim 1, in which said base structure is formed of six rectilinear base elements of substantially equal length, a parallel pair of said base elements defines a primary base plane, connected pairs of said base elements at opposite ends of said parallel pair form secondary base planes, and said secondary base planes are parallel and lie at angles to said primary base plane.

3. The reticular structure of claim 2, in which the apex of each of. the said connected pairs of base elements is engaged with an element of the tripod structure which has its apex on the same side of said primary base plane.

4. The reticular structure of claim 3, in which said secondary base planes lie at angles on the order of 35 degrees to said primary base plane.

- 5'. The reticular structure of claim 4, in which the length of said tripod elements is on the order of 1 /2 times the length of said base elements.

6. A reticular structure formed of interconnected structural modules, :in which a module comprises abase structure of generally hexagonal outline formed of rectilinear elements of substantially equal, predetermined length, and two tripod structures extending in opposite directions from said base structure, said tripod structures comprising rectilinear tripod elements joined at their outer ends and engaged at their base ends with alternate apices of said base structure, the elements of the respective tripod structures being engaged with different apices of said base structure, and said tripod elements being of substantially equal length and on the order of 1 /2 times the length of said base elements.

7. A reticular structure formed of interconnected structural modules, in which a module comprises a base structure of generally hexagonal outline formed of rectilinear elements of substantially equal length, and two tripod structures extending in opposite directions from said base structure, said tripod structures comprising rectilinear tripod elements joined at their outer ends and engaged at their base ends with alternate apices of said base structure, the elements of the respective tripod structures being engaged with different apices of said base structure, and the modules of said reticular structure being formed of structural parts forming elements in a plurality of modules.

8. The reticular structure of claim 7, in which said structural parts are of two types, the structural parts of one type form two tripod elements and one base element, and the structural parts of the other type form one tripod element and two base elements.

9. A reticular structure, formed of interconnected structural modules, in which a module comprises a base structure of generally hexagonal outline and formed'of rectilinear elements, and two tripod structures formed of rectilinear elements and extending in opposite directions from said base structure, the elements forming a tripod structure being connected at their outer ends and being connected to alternate apices of said base structure, and the connected elements being mechanically self-interlocked at joints to resist forces applied along the axes of the elements.

No references cited.

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