US3908975A

US3908975A - Construction apparatus

Info

Publication number: US3908975A
Application number: US440065A
Authority: US
Inventors: Donald R Bryant
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-02-05
Filing date: 1974-02-05
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

An apparatus comprising a jig and method for using such jig for the construction of geometric framework segments such as triangular segments, of construction materials such as rods, bars, tubes, etc. which are constructed to provide a generally curved cross-sectional appearance and which are utilized in the construction of geodesic framework which serve as reinforcing and/or support for geodesic domes. Additionally, a geodesic framework is provided which may be readily and simply constructed.

Description

United States atent 1191 Bryant 1451 Sept. 30, 1975 1 CONSTRUCTION APPARATUS [76] Inventor: Donald R. Bryant, Rt. 2, Box 93-A,

Alta Loma, Tex. 77510 [22] Filed: Feb. 5, 1974 [21] Appl. No.2 440,065

269/40, 41, 43, 45, 289, 296, 311, 321 F, 321 S; 29/200 P, 200 J, 160

3,458,182 7/1969 Flachbarth et a1 269/41 FOREIGN PATENTS OR APPLICATIONS 82,115 11/1963 France 52/81 Primary Examiner-Granville Y. Custer, Jr. Assistant E.raminerNei1 Abrams [5 7 1 ABSTRACT An apparatus comprising a jig and method for using such jig for the construction of geometric framework segments such as triangular segments, of construction materials such as rods, bars, tubes, etc. which are constructed to provide a generally curved cross-sectional appearance and which are utilized in the construction [56] Ref Ci d of geodesic framework which serve as reinforcing and- UNITED STATES PATENTS /or support for geodesic domes Additionally, a geode l 755 031 W930 S h kl 269/45 x sic framework is provlded W1'11C11 may be readily and 1 C ITIUC er 1,822,270 9/1931 Bunch 269/40'X slmply constructed 2,978,074 4/1961 Schmidt 52/81 2 Claims, 6 Drawing Figures US. Patent Sept. 30,1975

Sheet 1 0f 3 US. Patent Sept. 30,1975

Sheet 2 of 3 US. Patent Sept. 30,1975 Sheet 3 of3 3,908,975 V HGURE 5 FIGURE 6 CONSTRUCTION APPARATUS BACKGROUND OF THE INVENTION The present invention relates to the construction of geodesic domes. More particularly, the present invention relates to the apparatus useful in the construction of geodesic domes and to a method for the construction of such domes.

Geodesic domes represent a form of structure simple in construction and yet very useful, particularly, for warehousing or other commercial use, as well as low cost housing. Such structures are in general stronger and yet less expensive than structures providing a like amount of usable internal space. In construction, these geodesic domes are often comprised of concrete or other moldable materials containing internal reinforcing materials. For many purposes, however, such geodesic domes are constructed of a geodesic framework of rods, bars or tools, which then serve to support some external covering upon such framework or an internal covering suspended from within such framework.

One of the primary problems encountered in constructing geodesic domes employing a geodesic framework, either as reinforcing or as a supporting structure as above discussed, is the difficulty of putting together the framework, whether it be for reinforcing or for supporting. Presently, such frameworks generally are put together rod by rod from the ground up which is slow, requires considerable manpower and extensive scaffolding or other means for supporting constructiona personnel. In other instances, it has been proposed to put geometric segments together first and then construct the geodesic dome by putting the geometric segments together, However, under present methods, the construction of such geometric segments also is a slow and tedious operation and most frequently, such segments are relatively small with no curvature within the segment. Thus, the geodesic framework resulting, while having an overall curved appearance, is in truth constructed of segments having straight, non-curved members which in turn, results in a reduction of strength within the segment and thus, within the final geodesic framework.

It is now an object of the prescnt invention to provide a new and improved apparatus and method for use in the construction of geodesic domes.

Another object of the present invention is to provide a new apparatus and method for producing geometric segments for coupling together to form geodesic frameworks for reinforcing and/or supporting of geodesic dome structures.

A remaining object of the present invention is to provide a new method for the construction of geodesic frameworks for either reinforcing or supporting of geodesic dome structures.

Additional objects of the present invention will become apparent from the following description of the invention herein disclosed.

SUMMARY OF THE INVENTION The present invention, which fulfills these and other objects, is in one of its embodiments, an apparatus for the construction of geometric segments which are used in the construction of geodesic frameworks for reinforcing and/or supporting geodesic domes, said apparatus comprising (a) a first. second and third peripheral guide member, said first, second and third peripheral guide members aligned to form the legs of a triangle, the ends of each of said first, second and third peripheral guide members being spaced apart from one another to thereby leave an opening therebetween at the point which would otherwise be the apex of the triangle so formed, each of said peripheral guide means lying in a common spherical plane to the other peripheral guide member and each of said peripheral guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, (b) a first, second and third transverse .guide members, said first, second and third transverse guide members extending from adjacent to but spaced apart from said first, second and third peripheral guide members, respectively, in a line along an arcuate path to adjacent but spaced apart from another of said legs of the triangle formed by said peripheral guide members, all of the guide members of each of said first, second and third transverse guide members being substantially parallel to and lying within a common arcuate plane to all other guide members of each of said first, second and third transverse guide members, each of said transverse guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, said guide means being spaced apart at the point where it would otherwise intersect and cross a line drawn through spaced apart guide means of a guide members transverse thereto, said arcuate plane of each of said first, second and third transverse guide members being substantially parallel and spaced apart from one another a distance approximately equal to the thickness of the material to be guided by said guide means in the course of using said apparatus for the construction of geometric segments for the ultimate construction of geodesic domes, and one of said arcuate planes of said first, second and third guide transverse guide members lying such that the guide members therein will terminate such that outward extension thereof would intersect the line formed by the peripheral guide members adjacent each end thereof.

In another embodiment, the present invention is a method for the construction of geometric segments employed in the construction of the framework for geodesic domes, said method comprising (1) aligning three construction members in the form of a triangle to form the peripheral legs of said triangle, the ends of each of said three construction members joining an end of another of said construction members at each end thereof, such joinder being in the same plane, to thereby form an apex of said triangle, said three construction members lying in a common spherical plane, (2) aligning a plurality of construction members transversely to the peripheral members, such transverse construction members being in three groups, each of said groups of construction members being aligned parallel to a different peripheral construction member and each of said transverse construction members being in contact with a peripheral construction member at each end thereof and equidistantly spaced apart from the 7 other construction member and the apex of the triangle opposite said parallel peripheral construction member, one of said groups of transverse construction members being aligned in the same spherical plane in which said peripheral construction members lie and the other groups of transverse construction members being aligned so that all members of said group lie in different but parallel spherical planes, but in cross-over contact with the transverse construction members which lie in the plane common with the peripheral construction members, one of said groups lying below said plane common to said peripheral construction members and the other group lying above said plane common to said peripheral construction members, and (3) joining in fixed relation the transverse construction members to one another at the points of cross-over contact with one another and to said peripheral construction members at the points of contact therewith.

In still other embodiments, the present invention comprises a geodesic dome framework and a method for its construction, said geodesic dome framework being comprised of a plurality of triangular segments joined together, said triangular segments being comprised of two types, one of said types being equilateral and the other of said types being non-equilateral but having a first leg thereof of the same length as the legs of said equilateral triangle and the second and third legs thereof the same length but shorter than said first leg, said second and third legs of said non-equilateral triangles being a length ratio to said first leg of 0.80:1 to 0.95:1, said lower equilateral triangular segments being spaced apart horizontally with one leg thereof being parallel and adjacent to the surface upon which said framework is to be constructed, and another and upper of said equilateral triangular segments joining said lower equilateral triangular segment at its upper apex, such joining being apex to apex with an upper leg of said upper equilateral triangular segments being parallel to said lower leg of said lower equilateral triangular segment to which said upper equilateral triangular segment is joined, each of said upper equilateral triangular segments being joined to one another at an outer apex thereof, five of said non-equilateral triangular segments being interspaced between each joined set of upper and lower equilateral triangular segments in such manner as to make up five equal segments of a pentagon, the outer leg of each of said five non-equilateral triangular segments being the said first leg thereof, the first leg of the lower most of said five non-equilateral triangular segments being horizontal and adjacent to the surface upon which said framework is to be constructed and continuous with the lower leg of said lower equilateral triangular segment, and the first leg of the remaining four non-equilateral triangular segments being in contact with a leg of said adjoining equilateral triangular segments, five additional non-equilateral triangular segments positioned atop the upper equilateral triangular segments, these upper non-equilateral triangular segments each having the first leg thereof in contact with the upper leg of said upper equilateral triangular segments and said five upper non-equilatera triangular segments coming together to form a pentagon, all of said triangular segments being made up of the above said legs and having a plurality of spaced apart transverse members parallel to each of said legs and in fixed contact with said legs at the end of said transverse members and being in fixed contact with one another at the cross-over points thereof, all of said legs and said transverse members having an arcuate shape the curvature of which is in accordance with the spherical curvature of the framework to be constructed.

DESCRIPTION OF THE DRAWINGS FIG. I of the drawings is a top view of the embodiment of the present invention comprising an apparatus for the construction of triangular segments useful in the construction of geodesic domes.

FIG. 2 of the drawings in a cross-sectional view through Line AA of FIG. 1.

FIGS. 3a, 3b and 3c of the drawings are crosssectional views of two different embodiments of a detail of the apparatus for the construction of geometric segments which is one of the embodiments of the present invention.

FIGS. 4a and 4b of the drawings are cross-sectional views of a guide member of the apparatus for the construction of geometric segments in accordance with the present invention, particularly, illustrating such guide member equipped with a clamping device for clamping the construction members within said guide members.

FIG. 5 of the drawings is a side view of a geodesic dome framework constructed in accordance with the present invention.

FIG. 6 of the drawings is a side view of the two types of triangular segments employed in constructing the geodesic domes of the present invention illustrating their joined relationship to one another.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION In order to more fully describe the present invention in its several embodiments, reference is made to the accompanying drawings. In the drawings, the same reference characters in general, are used' throughout to denote like features of the invention.

Referring to FIGS. 1 through 4 of the drawings, various views and embodiments of the apparatus for the construction of geometric segments, which is one of the embodiments of the present invention, and details of said apparatus are depicted. This apparatus is provided with three

peripheral guide members

10, 11 and 12. As is noted from FIG. 1, the peripheral guide members 10, l l and 12 form the edges or legs of a triangle. In FIG. 1, the triangle is depicted as an equilateral triangle. However, as is hereinafter described, other triangular shapes are necessary to the construction of geometric domes and therefore, the apparatus of the present invention may be of suitable form to be used in constructing such other triangular shapes.

For reasons which will be more fully discussed hereinafter,

peripheral guide members

10, 11 and 12 do not join at the ends thereof but rather, stop short of such joinder thereby creating

openings

13, 14 and 15. In ad dition, each of

peripheral guide members

10, 11 and 12 are actually made up of spaced apart segments 16a, b, c and d, 17a, b, c and d and 18a, b, c and d, respectively. By spacing apart segments 16a, b, c and d of peripheral guide member 10, as well as their counterparts of peripheral guide members 11 and 12, side openings 19 are created. The purpose of such openings is discussed hereinbelow.

Extending from adjacent to

peripheral guide members

10, 11 and 12 are, respectively, first transverse guide members 20, second transverse guide members 21 and third transverse guide members 22. As illustrated in FIG. I, each of the first, second and third transverse guide members, 20, 21 and 22, respectively, include three parallel guide members. Of course, as the size of the geodesic triangle is increased or decreased, as the case may be, the number of such parallel guide members may either increase or decrease or remain constant but with greater or lesser spacing, as the case might be, between such guide members. All but one of each of said first, second and

third guide members

20, 21 and 22, respectively, are comprised of spaced apart segments of equal length (not separately characterized herein). Of considerable importance, is the alignment of first, second and

third guide members

20, 21 and 22, respectively. Each group of such guide members is aligned in substantially parallel relationship to one of the

peripheral guide members

10, 11 or 12. For example, the first guide members 20 are aligned parallel to peripheral guide member 12 and are approximately equidistantly spaced from one another. Likewise, the second and

third guide members

21 and 22 are aligned parallel to peripheral guide members and 11, re spectively, and also are equidistantly spaced from one another.

At the intersection of the first, second and

third guide members

20, 21 and 22, respectively, between the various segments thereof, an opening 23 is provided. The purpose of opening 23 will be explained hereinafter.

All of the guide members, whether

peripheral guide members

10, 11 and 12 or first, second and

third guide members

20, 21 and 22, are arcuate in their longitudinal extension. The degree of curvature of each of said arcuate members will be in accordance with the curvature of the geodesic dome to be constructed by use of the apparatus for forming the geometric segments which will be used to construct such geodesic dome as hereinafter described.

The first, second and third guide members each lie in different arcuate planes. For example, all of the first guide members lie in one arcuate plane, all of the second guide members 21 in a different arcuate plane and all of the third guide members 22 in still a different arcuate plane. The three arcuate planes in which the first, second and third guide members lie are at all times substantially parallel to one another and are spaced apart from one another a distance approximately equal to the vertical thickness of the construction materials of which the geometric segment is to be constructed. The spaced apart planear relationship of first, second and

third guide members

20, 21 and 22, respectively, is specifically illustrated by the crosssectional view of FIG. 2 of the drawings.

In FIG. 2, first guide members 20 are illustrated in an upper arcuate plane with intersecting second and

third guide members

21 and 22, respectively, shown in different planes therebelow. As is shown in FIG. 2, the various segments of the first, second and

third guide members

20, 21 and 22, respectively, are supported by support means 24 which extend upward from a supporting surface 25.

The supporting surface 25 may be a solid surface or a floor surface or may be a raised surface or frame for carrying support means 24. In a particular advantageous embodiment of the present invention, supporting surface 25 is a frame of structure generally similar to the structure described by the peripheral and first, second and third guide members except usually lying in a normal flat plane. In this advantageous embodiment, the frame is rotatedly mounted upon a single centrally located support 26. Such an arrangement permits rotation of the apparatus of the present invention and thereby, permits a workman assembling a geometric segment upon such apparatus, to remain in substantially the same place by rotating said apparatus to permit him access to all points of the geometric segment being constructed.

The guide members of the apparatus of the present invention may take any number of shapes. The V-shape shown in FIG. 3a is a particularly useful shape since ordinary, readily available angle-iron may be employed to form the guide member. Another useful shape is the U- shape illustrated by FIG. 3b. Still another useful shape is the L-shape, illustrated by FIG. 30. The purpose of the guide members, of course, is to guide and maintain substantially in place, the construction materials from which the geometric segment is to be constructed. Therefore, any shape of the guide member which will accomplish such purpose may be used and is within the scope of the present invention.

Due to the arcuate shape of the guide members of the present apparatus, it is necessary to employ materials for constructing the geometric segments which are prebent to the proper arcuate shape of such guide members or to in some manner, bend such construction materials as they are placed in the guide members. In this latter instance, it generally becomes necessary to restrain such construction materials in the arcuate shape of the guide members until all of the different construc tion members can be assembled together as hereinafter discussed. While this may be accomplished by any number of means, it is somewhat preferred to provide the guide members with a clamping means 27 such as is illustrated in FIGS. 4a and 4b. In FIG. 4a, such a clamping device 27 is shown in cross-section inclosed or clamping position holding a rod 28 snugly within the V-shaped guide member. FIG. 4b illustrates such clamping device 27 in open position. Referring to FIGS. 4a and 4b, the clamping device 27 is comprised of a hinge 29, a clamping body 30 and a latch head 31 which works in latching contact with latch hook 32 which is affixed to the side of the guide member opposite to the side to which hinge 29 is attached. Many other types and variations of latching devices may be employed with adequate success and are therefore, within the scope of the present invention.

While the apparatus for the construction of geometric segments has been shown in the drawings with reference to guide members having from end to end, an upward curvature, they can as well have a downward curvature. From the practical standpoint, it is somewhat easier to utilize such apparatus with the upward curvature and therefore, such upward curvature is more often employed. The degree of curvature, whether upward or downward, will vary with the size of the geodesic dome to be constructed from the geodesic segments and means for such determination are well known in the art and may readily be determined by those skilled in the art.

In constructing the geometric segments in accordance with the present invention, lengths of construction members of length at least sufiicient to extend from the peripheral guide members to the opposite peripheral guide members along the path of the first, second and third guide members, as the case may be, are placed in such first, second and third guide members. The construction materials may be rods, bars, tubes, angle-iron, etc. and may be of metal, wood or plastic. The choice of material will vary with the desires of the builder in accordance with strength desired, availability, cost and other like factors.

As indicated above, the construction members may be pre-bent to the arcuate shape of the first, second and third guide members or may be placed in such guide members and restrained therein by clamps or other means. Either before, after or concurrently therewith, construction members of length at least equal to the distance from apex to apex of the triangle formed by the peripheral guide members, are placed in such peripheral guide members. When such construction members are retained within the various guide members, then they will be in contact with one another at the various cross-over points or

openings

13, 14, 15 and 19 of the peripheral guide members and 23 of the first, second and

third guide members

20, 21 and 22, respectively. The construction members lying within the various guide members, may then be readily fastened to one another at the various contacting points. Such fastening may be accomplished by welding, cementing, clamping or any other means suitable for fastening the materials of construction together in fixed relationship. Since the cross-over contacting points lie within the openings l3, l4, 15, 19 and 23, such fastenings may be readily accomplished without damage to or obstruction from the various guide members. Should any of the construction members employed in constructing the geometric segment be longer than the above defined minimum length, the excess is cut off at some point in time prior to incorporation of the constructed geometric segment into a geodesic dome. After the fastening is complete, the resulting geodesic triangle is removed from the apparatus and is now ready for assembly into a geodesic dome.

The geodesic dome frameworks constructed in accordance with the present invention, illustrated in FIGS. and 6, comprise at least two different types of triangular segments. The first type is the equilateral triangle 33 having three legs 34 of equal length. Such equilateral triangular segments 33 are constructed as above described employing the construction apparatus of the present invention. The other type of triangular segments are the non-equilateral triangular segments 35. Such non-equilateral triangular segments 35 have a first leg 36 of a length which is the same as the legs 34 of equilateral triangular segments 33. The remaining

legs

37 and 38 of non-equilateral triangular segments 35 are of the same length but shorter than the first leg 36 thereof. In accordance with the present invention, the

legs

37 and 38 generally, will have a length ratio with respect to leg 36 within the range of 0.85521 to 0.94:1. For example, if leg 36 is feet, then

legs

37 and 38 will have a length within the range of 8.55 to 9.4 feet. Usually, this ratio will be approximately 0.88:1 to 0.89:1, preferably about 0.888z1. Variations within these ranges may result in the surface of the geodesic dome being irregular with intermittent indentations or extensions but shall remain in a generally curved or spherical shape.

In the particularly useful geodesic dome frameworks and means of constructing such geodesic comes, in accordance with the present invention, equilateral triangular segments 33 are equidistantly spaced apart about the base circular line of the dome framework to be constructed. Such lower or base triangular segments 33a have a base leg 39 thereof parallel and situated upon the surface 40 upon which the dome framework is to be constructed and are spaced apart from one another a distance along the base line of the dome to be constructed, equal to the length of the legs 34 of said triangular segments 33.

As illustrated in FIG. 5, a lower or base nonequilateral triangular segment 35a is spaced between base equilateral triangular segments 33a with its longer or first leg 36 parallel to and resting upon surface 40. Such first leg is continuous with the base legs 39 of the two adjoining equilateral triangular segment 35a are four non-equilateral triangular segments 35b. Such non-equilateral triangular segments 35b join one with another and segment 35a to form a pentagon. The first leg 36 of each of said non-equilateral triangular segments 35b form the periphery of such pentagon.

An upper equilateral triangular segment 33b is connected to each of the base equilateral triangular segments 33a at the upper apex of said base equilateral triangular segments. In such alignment, the upper leg 41 of each such upper equilateral triangular segments is in parallel relation to the base leg 39 of the base equilateral triangular segment 33a. Each of said upper equilateral triangular segments 33b are joined to each other segment 33b at the apexes thereof at the ends of upper leg 41 thereof. The side legs 42 of each of said upper equilateral triangular segments 33b lies along and is joined to a first leg 36 of the adjacent non-triangular segments 35b. Such joinder of the apexes and legs of such upper equilateral triangular segments results in a continuous line composed of upper legs 41 forming the outer edges of a pentagon, as viewed from above. A circular line drawn through the points ofjoinder of upper legs 41 will be of significantly reduced diameter with comparison to the base line of the geodesic dome being constructed which in turn results in the spherical curvature of the framework composed of the various equilateral and non-equilateral

triangular segments

33a, 33b, 35a and 35b which are joined together as above described.

Fixed to each of the upper legs 41 of upper equilateral triangular segments 33a is the first leg 36 of the upper non-equilateral triangular segments 35c. The side legs 43 of each of upper non-equilateral triangular segments 35c are joined to one another and the upper apex of each such segment 35c joins the upper apex of each other such segment 350. Such joinder results in closure of the dome across the top of and in conjunction with the joinder of the various

triangular segments

33a, 33b, 35a and 35b, as above described, completes formation of a geodesic framework.

In order that the geodesic framework be complete from the standpoint of practical usage, it is desirable that one or more door openings for ingress and egress into and out of the domed framework be provided. Also, it may be desirable to leave window openings for the circulation of air and passage of light. The door openings in the framework may be readily created by leaving out one or more of the base

triangular segments

33a or 35a. Window openings may be created by removing or leaving out during construction of one or more of the segments of transverse members. Within these windows and/or door openings, the appropriate shape for the opening, i.e., rectangular, square, etc, may be readily framed.

After completion of the geodesic framework, the geodesic dome may be constructed upon such framework. In completing the dome, the framework may serve as the structural bracing for concrete or other moldable material which may be molded about the framework. When such moldable materials as concrete are employed, it is generally desirable to employ a mold internally just below the framework and then fill the mold to above the framework thereby enclosing the framework within the molded structures. In other similar embodiments, the framework may be covered with a fine wire mesh on one or both sides and an appropriate moldable material sprayed or spread upon the wire mesh. In other embodiments, the framework may be covered with a flexible covering, such as polypropylene film, a canvas tarpaulin, etc., or may serve to support a similar covering material which is placed within the framework but supported thereby. The particular mode or material employed in constructing a geodesic dome from the geodesic framework described herein may vary widely depending upon the intended use of the dome, the desires of the builder, availability of materials, etc. However, so long as the present geodesic framework is employed to reinforce or to support the covering or enclosing material, then such geodesic domes are within the spirit and scope of the present invention.

I claim:

1. An apparatus for the construction of geometric segments which are used in the construction of geodesic frameworks for reinforcing and/r supporting geodesic domes, said apparatus comprising (a) a first, second and third peripheral guide member, said first, second and third peripheral guide members aligned to form the legs of a triangle, the ends of each of said first, second and third peripheral guide members being spaced apart from one another to thereby leave an opening therebetween at the point which would otherwise be the apex of the triangle so formed, each of said peripheral guide means lying in a common spherical plane to the other peripheral guide member and each of said peripheral guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, (b) a first, second and third transverse guide members, said first, second and third transverse guide members extending from adjacent to but spaced apart from said first, second and third peripheral guide members, respectively, in a line along an arcuate path to adjacent but spaced apart from another of said legs of the triangle formed by said peripheral guide members, all of the guide members of each of said first, second and third transverse guide members being substantially parallel to and lying within a common arcuate plane to all other guide members of each of said first, second and third transverse guide members, each of said transverse guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, said guide means being spaced apart at the point where it would otherwise intersect and cross a line drawn through spaced apart guide means of a guide member transverse thereto, said arcuate plane of each of said first, second and third transverse guide members being substantially parallel and spaced apart from one another a distance approximately equal to the thickness of the material to be guided by said guide means in the course of using said apparatus for the construction of geometric segments for the ultimate construction of geodesic domes, and one of said arcuate planes of said first, second and third guide transverse guide members lying such that the guide members therein will terminate such that outward extension thereof would intersect the line formed by the peripheral guide members adjacent each end thereof.

2. The apparatus of claim 1 wherein said guide members are all constructed of angle-iron.

Claims

1. An apparatus for the construction of geometric segments which are used in the construction of geodesic frameworks for reinforcing and/or supporting geodesic domes, said apparatus comprising (a) a first, second and third peripheral guide member, said first, second and third peripheral guide members aligned to form the legs of a triangle, the ends of each of said first, second and third peripheral guide members being spaced apart from one another to thereby leave an opening therebetween at the point which would otherwise be the apex of the triangle so formed, each of said peripheral guide means lying in a common spherical plane to the other peripheral guide member and each of said peripheral guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, (b) a first, second and third transverse guide members, said first, second and third transverse guide members extending from adjacent to but spaced apart from said first, second and third peripheral guide members, respectively, in a line along an arcuate path to adjacent but spaced apart from another of said legs of the triangle formed by said peripheral guide members, all of the guide members of each of said first, second and third transverse guide members being substantially parallel to and lying within a common arcuate plane to all other guide members of each of said first, second and third transverse guide members, each of said transverse guide members being comprised of a plurality of spaced apart, longitudinally aligned guide means, said guide means being spaced apart at the point where it would otherwise intersect and cross a line drawn through spaced apart guide means of a guide member transverse thereto, said arcuate plane of each of said first, second and third transverse guide members being substantially parallel and spaced apart from one another a distance approximately equal to the thickness of the material to be guided by said guide means in the course of using said apparatus for the construction of geometric segments for the ultimate construction of geodesic domes, and one of said aRcuate planes of said first, second and third guide transverse guide members lying such that the guide members therein will terminate such that outward extension thereof would intersect the line formed by the peripheral guide members adjacent each end thereof.