BACKGROUND OF THE INVENTION 1. Field of the Invention
The invention is a prefabricated, portable, structural module, which can be used singly or connected in series to form a structural element, a space frame or a truss. The invention primarily pertains to patent classification 52, as a static structural element, but may also pertain to classification 14 with respect to portable, trusses for bridges. Examples of similar Classification 52 devices appear in U.S. Pat. Nos. 5,003,748 and 6,205,736. Classification 14 previous patents include temporary bridging such as UK Patent 553,374, U.S. pat. Nos. 4,912,795 and 5,065,467.
2. Background Art
The invention differs from previous patents in that simple, 3-member or 5-member, prefabricated, modules are used exclusively to assemble a structural element, space frame or truss. The invention is easily fabricated, portable and allows flexibility in the scale of the invention, which in turn provides the invention with nearly limitless utility as a structural element. Design variables of the invention are: member size, strength of materials and ultimate configuration. Any appropriate, structural section and material can be used to fabricate modules. Configurations can include combinations similar to prior inventions such as the “Bailey Bridge” system, and others, in which trusses are connected together to form multiple-truss and multiple-story structures.
Because the invention can be designed and configured as a space frame or a truss, limitations associated with member eccentricities imposed by ideal truss design are eliminated. Although frame analysis is more complex, using computer assisted design methods readily facilitates analysis and design. Modules consist of three (3) or five (5) structural members fabricated into a basic “Z” shape. A 3-member module is modified to a 5-member module by the addition of vertical members at each end. A module can be used singly or further assembled by connecting a series of modules in a pattern or repeating orientation into a structural element. A space frame or truss can be assembled from a structural element by the addition of end units consisting of single end posts or special ends comprised of more than one member. Module-to-module connections are chord splices with the details dependent on load capacity and deflection requirements of the structure. Modules can be combined during fabrication by using continuous chord members thereby requiring fewer chord connections when erected.
SUMMARY OF INVENTION The main object of the invention is to provide a simple, prefabricated, portable, structural module, which is assembled into a structural element, a structural frame or a truss. The invention's design parameters can be varied to create small or large structural elements capable of long, single spans, but still allow simple fabrication, transportation and erection. The basic building block is a structural module comprised of three (3) or five (5) members: Two (2), parallel, chord members are connected together by a diagonal member to form a 3-member module in the shape of a “Z”. Addition of two (2), vertical members at the ends of the parallel chord members form a 5-member module. Single end posts or special end sections consisting of more than one member are added at the ends of a structural element as needed to form a complete space frame or truss.
The second object of the invention is to create a portable structural frame or truss with a wide range of utility for permanent, temporary or emergency structures. Load capacities and span lengths for the invention can be designed for individual applications or can be determined by load capacity charts for standard module sizes. Span length and load capacity requirements determine the scale of the invention. Frames or trusses assembled from large modules can be designed for clear spans in excess of 300 feet capable of supporting loads in excess of 50 tons. The modules are prefabricated from any material with appropriate structural properties.
Another object of the invention is to reduce structural fabrication, transportation and erection costs. The 3-member modules of this invention require two (2) permanent connections, representing a useful simplicity of fabrication. Prefabricating a series of combined modules using continuous chord members increases the invention's efficiency by decreasing the number of chord connections required during erection and providing a control on length and weight for purposes of transportation and erection.
In summary, the invention is a simple, structural module of variable size, which is easily fabricated, transported and erected. The modules are prefabricated, and used as structural elements, space frames, or trusses. High load capacities and long, clear spans are possible due to the invention's inherent flexibility of design, which also allows the invention a range of utility for use in temporary, permanent or emergency structures on any scale required.
DESCRIPTION OF DRAWINGS FIG. 1A is an elevation view of a structural element illustrating large eccentricities at member connection points, which require space frame analysis.
FIG. 1B is an elevation view of a structural element illustrating small or no eccentricities at member connection points, which allow ideal truss analysis.
FIG. 1C is an isometric view of a single, 3-member, space frame module with individual members labeled.
FIG. 1D is an isometric view of a single, 3-member, truss module with individual members labeled.
FIG. 2A is an isometric view of a single, 5-member, space frame module, illustrating addition of vertical members to the ends of a 3-member, module to form a 5-member, space frame module.
FIG. 2B is an isometric view of a single, 5-member, truss module, illustrating addition of vertical members to the ends of a 3-member, module to form a 5-member, truss module.
FIG. 3A is an isometric view of a structural element comprised of two (2), 3-member, space frame modules connected in a mirror image orientation.
FIG. 3B is an isometric view of a structural element comprised two (2), 3-member, truss modules connected in a mirror image orientation.
FIG. 4A is an isometric view of a structural element (or frame) comprised two (2), 5-member. Space frame modules connected in a mirror image orientation.
FIG. 4B is an isometric view of a structural element (or truss) comprised two (2), 5-member, truss modules connected in a mirror image orientation.
FIG. 4C is an isometric view of a space frame comprised of two (2), 3-member, space frame modules connected in a mirror image orientation with multi-member end sections.
FIG. 4D is an isometric view of a space frame comprised two (2), 3-member, truss modules connected in a mirror image orientation with multi-member end sections added to create a space frame.
FIG. 5A is an isometric view of a space frame comprised of four (4), 3-member, space frame modules connected in a mirror image orientation with single member end sections.
FIG. 5B is an isometric view of a Warren truss comprised of four (4), 3-member, truss modules connected in a mirror image orientation with single member end sections.
FIG. 6A is an isometric view of a structural space frame assembled using four (4), 5-member, space frame modules connected in a mirror image orientation.
FIG. 6B is an isometric view of a Warren truss with verticals assembled using four (4), 5-member, truss modules connected in a mirror image orientation.
FIG. 7A is an isometric view of two (2) structural, space frames consisting of four (4), 3-member, space frame modules each, in turn connected together to form a single story, double frame configuration.
FIG. 7B is an isometric view of four (4) space frames consisting of four (4), 3-member, space frame modules each, with single member end sections. The frames are then connected together horizontally and vertically in a double frame—double story arrangement.
FIG. 7C is an isometric view of a space frame comprised of four (4), 3-member, space frame modules in a symmetric pattern mirrored at half span.
FIG. 7D is an isometric view of a space frame assembled from four (4), 3-member, space frame modules connected in series illustrating another variation.
FIG. 8 is an isometric view of a space frame connected to large, structural, chord members. The figure illustrates using the frame as a web for a large, built-up member, but also illustrates how a frame and another beam can be used to support an existing beam.
FIG. 9 is an isometric view of 3-member, structural elements used as bracing between two (2) columns.
FIG. 10 is an isometric view of tubular, 3-member truss members used as structural elements between the columns of a tubular tower structure.
FIG. 11 is an isometric view of 3-member, truss and frame modules prefabricated with continuous chord members to reduce the number of field chord connections and create a convenient length for transportation and erection.
FIG. 12 is an isometric view of 5-member truss modules used to assemble a rectangular tower structure and a similar rectangular tower next to first assembled from 3-member modules used as structural elements attached to continuous columns.
FIG. 13 is an elevation view of 5-member frame modules assembled to form an arch.
DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1A demonstrates the case for which space frame design is required. Large eccentricities between projected points of intersection (POI) of diagonal member centerlines CL and the centerlines CL of chord members are large and do not coincide. Modules A, B, C and D are typical, space frame modules. The point of intersection (POI) of projected centerlines CL of diagonal members 101 in modules A and B and modules C and D lie above the centerlines CL of upper chord members 100. The point of intersection (POI) of the projected centerlines CL of diagonal members 101 in modules B and C lie below the centerlines CL of lower chord members 102. Eccentricities in space frame modules are created due to the ends of chord members 100 and 102 extending past the ends of diagonal members 101.
FIG. 1B demonstrates the case for which ideal truss design is acceptable. Generally speaking, eccentricities are eliminated and points of intersection (POI) of member centerlines CL coincide or eccentric distances are negligible. Ideal truss design requires a combination of connected triangles. Modules AA, BB, CC and DD are typical truss modules. The point of intersection (POI) of projected centerlines CL of diagonal members 11 in modules AA and BB and modules CC and DD intersect with the centerlines CL of upper chord members 10. The point of intersection (POI) of projected centerlines CL of diagonal members 11 in modules BB and CC intersect with the centerlines CL of lower chord members 12. Eccentricities in truss modules are eliminated due to the ends of chord members 10 and 12 ending exactly at the ends of diagonal members 11. Very small eccentricities are acceptable.
FIG. 1C is a 3-member, space frame module illustrating upper chord 100, diagonal 101 and lower chord 102. Chord members 100 and 102 in the space frame configuration extend well past the ends of diagonal member 101.
FIG. 1D is a 3-member, truss module illustrating upper chord 10, diagonal 11 and lower chord 12. The ends of chord members 10 and 12 do not extend past the ends of diagonal 11 in this configuration.
FIG. 2A is a 5-member, space frame module. Upper chord 100, diagonal 101 and lower chord 102 are converted from a 3-member module as shown in FIG. 1C to a 5-member module by the addition of vertical members 103 at each end of the chord sections 100 and 102.
FIG. 2B is a 5-member, truss module. Upper chord 10, diagonal 11 and lower chord 12 are converted from a 3-member module as shown in FIG. 1D to a 5-member module by the addition of vertical members 13 at each end of the chord sections 10 and 12.
FIG. 3A shows two (2), 3-member, space frame modules A and B, connected in a mirror image orientation. Both modules are identical, but module B is rotated to a mirror image orientation. Upper chord module connections 100, module A to 100, module B and lower chord connections 102, module A to 102, module B are designed as chord splices.
FIG. 3B shows two (2), 3-member, truss modules AA and BB, connected in a mirror image orientation. Both modules are identical, but module BB is rotated to a mirror image orientation. Upper chords connections 10, module AA to 10, module BB and lower chord connections 12, module AA to 12, module BB are designed as chord splices.
FIG. 4A shows two (2), 5-member, space frame modules; A and B connected in a mirror image orientation. Addition of vertical members 103 converts a 3-member module consisting of members 100, 101 and 102 to a 5-member module. To assemble a complete space frame, modules are added in similar fashion until a full span length is assembled. No additional end sections are required for 5-member, space frame modules.
FIG. 4B shows two (2), 5-member, truss modules; AA and BB connected in a mirror image orientation. Addition of vertical members 13 converts a 3-member module consisting of members 10, 11 and 12 to a 5-member module. To assemble a complete truss, modules are added in similar fashion until a full span length is assembled. No additional end sections are required for 5-member, truss modules.
FIG. 4C illustrates two (2), 3-member, space frame modules; A and B connected in a mirror image orientation with multi-member end sections; C consisting of members 104, 105 and 106 added to complete a frame. This case demonstrates the use of special end sections C comprised of several structural members. The special end sections C are used in lieu of a simple end post configuration. Splices to upper chords 100 and lower chords 102 of Modules A and B connect the end sections C.
FIG. 4D illustrates a space frame configuration using two (2), 3-member, truss modules; AA and BB connected in a mirror image orientation, made into a completed space frame element by using multi-member end section modules CC comprised of members 14, 15 and 16 at the ends of the modules. The multi-member end sections CC used in this case do not maintain a series of connected triangles necessary for ideal truss analysis and therefore the completed element as a whole must be designed as a space frame and not a truss. Splices to upper chords 10 and lower chords 12 of Modules AA and BB connect the end sections CC.
FIG. 5A and FIG. 5B show four (4), 3-member, modules; A, B, C, D (space frame modules) and AA, BB, CC, DD (truss modules) in completed space frame and truss configurations, respectively. These figures demonstrate the use of simple end posts 103 and 13. All module members and connections are as previously identified. This configuration if rotated 90 degrees can be used as a column or portion of a column if used in combination such as a rectangular tower as illustrated in FIG. 12 below.
FIG. 6A and FIG. 6B show four (4), 5-member, modules: A, B, C, D (space frame modules) and AA, BB, CC, DD (truss modules) in completed space frame and truss configurations, respectively. No additional end sections are necessary to complete the frame or truss for 5-member modules due to verticals 103 and 13 at the ends of each module. All module members and connections are as previously identified. This configuration can also be used to form columns when rotated 90 degrees vertically.
FIG. 7A depicts a multiple element space frame configuration (double) with 2 complete space frames of four (4), 3-member, modules each. End posts 103 are used at the end of each span to complete each frame. Individual modules; A, B, C, D, comprise one space frame and modules; E, F, G, H form another. All module members and connections are as previously identified. In addition to chord splices within each frame, the frames are connected to each other top chord to top chord and bottom chord to bottom chord in a horizontal plane to realize full, synergistic, load capacity of the combined frames.
FIG. 7B is a double frame element as in FIG. 7A, further assembled into a double frame-double story element consisting of four (4), complete, space frames comprised of four (4), 3-member, space frame modules each with end posts 103 at ends of the connected modules to compete each space frame element. Individual modules in the bottom pair of frames are labeled A through D on the inboard frame and E through H on the outboard frame. Individual modules in the top pair of frames are labeled I through L inboard and M through P outboard. In addition to chord splices, the frames are connected to each other side-to-side in a horizontal plane as in FIG. 7A and top chord-to-bottom chord in a vertical plane so that full synergistic load capacity of the combined frames is realized. Similar configurations as those shown in FIG. 7A and 7B have been used in the “Bailey Bridge” and other panel truss bridging systems since World War II.
FIG. 7C illustrates a variation in module orientation. Instead of every module being connected as a mirror image of the previous module, modules A and B are placed identically end-to-end for one half of a span. The other half of the span comprised of modules C and D is similar, but the module orientation is opposite in direction. All members within the modules are as previously identified. End Posts 103 are used at the ends of the span to complete the structural element.
FIG. 7D depicts another variation in module orientation. All modules A, B, C, and D are oriented in the same direction. All members within the modules are as previously identified. End Posts 103 are used at the ends of the span to complete the structural element.
FIG. 8 illustrates a modular space frame used in conjunction with other, non-modular, structural member(s) to create a new, structural element or to brace an existing structural element in place. Chord beams 200 and 202 are connected to top and bottom of modular space frame chord members 100 and 102, respectively to form a new, structural member with a large flexural capacity. If member 200 is considered an existing structural beam in place, the invention consisting of members 100, 101, 102 and 103 combined with (or without) structural member 202 depict the invention's utility as a strengthening or bracing element as may be required in a permanent or temporary repair, or an emergency structural situation.
FIG. 9 illustrates frame modules used as bracing for columns 200. All frame members are as previously identified.
FIG. 10 shows tubular, 3-member truss modules members 10, 11 and 12 used as bracing for a tubular column arrangement to create a tower.
FIG. 11 illustrates the use of continuous top chord and bottom chords. Section A illustrates a series of truss modules with continuous upper cord 10 and lower chord 12 of equal length. Diagonals 11 are attached in a mirror image orientation to form an entire section of truss modules. This configuration maintains the module concept, as the chords are equal in length. Section B illustrates the continuous chord configuration for a frame section with upper chord 100 and lower chord 102 again the same length. Diagonals are shown in a mirror image orientation. The continuous chord, prefabricated section can be used to eliminate some of the chord splices required where a long series of individual modules would otherwise be used. The continuous chord length can be adjusted to achieve the most economical length for transportation and erection purposes. The small number of connections demonstrates the invention's economy in fabrication.
FIG. 12 demonstrates the use of modules in two (2) ways. Tower A represents a truss comprised of 5-member truss modules rotated 90 degrees to create the sides of the tower. Upper chord 10, diagonal 11 and lower chord 12 are made into 5-member modules using end posts 13. Tower B illustrates the use of 3-member truss modules as structural elements in combination with continuous columns to create a tower similar to Tower A. Upper chord 10 diagonal 11 and lower chord 12 represent 3-member modules. Interior chord members are shown as single members instead of doubled in this figure for clarity. The columns COL are shown as continuous columns. The figure demonstrates the flexibility of the invention by allowing the most economical and practical combinations for the intended purpose to be used. The 5-member arrangement may be preferable for transportation and erection while the 3-member arrangement may be preferable if continuous columns are more economical or if the columns were existing columns.
FIG. 13 illustrates the use of 5-member frame modules to create and arched, structural element or frame. All of the members are as previously identified, upper chord members 100, diagonals 101, lower chord members 102, and end or vertical members 103. The invention allows the use of tapered verticals or mitered chord ends to create camber or an arched element as seen here.
