The invention relates to structural assemblies for constructing bridges and other structures.
Bridges, including pedestrian bridges and vehicular bridges, have a wide range of applications. For example, pedestrian bridges can be used in skywalks between buildings, gangways to embark or disembark ships and other vehicles, elevated walkways in architectural interiors, boardwalks, and any other setting where people move.
Currently, pedestrian bridges are often formed of welded components. Such bridges tend to be complicated and potentially expensive to assemble and often need to be transported to their site pre-assembled. Where welded bridges are assembled on-site, as may be the case in larger structures, assembly can be laborious, expensive and complicated, requiring intervention of highly-skilled welders and other professionals. Also, such bridges tend to be permanent, since their assembly is generally irreversible and they sometimes can only be removed by destructive deconstruction.
Pedestrian bridges that are not welded or that are generally disassemblable tend to suffer from a number of drawbacks, including being susceptible to vandalism, tampering, and accidental disassembly. Such acts can have devastating consequences, particularly in cases of bridges that can fail and cause human loss if intentionally or unintentionally weakened or disassembled. Additionally, such bridges tend to have highly visible weld lines which are detrimental to their aesthetic appeal.
Similar considerations can also arise in vehicular bridges. Furthermore, similar considerations can also arise in other types of structures, such as buildings, fences, towers (e.g., antennae tower), gantries (e.g., motorway gantries, crane gantries, etc.), to name a few.
For these and other reasons, there is a need for improvements in structural assemblies for constructing bridges and other structures.
According to a first broad aspect, the invention provides a structural assembly. The structural assembly comprises an elongated member defining an internal space. The structural assembly also comprises a plurality of framing members connected to the elongated member at a plurality of pin connection nodes, each pin connection node comprising a pin interconnecting the elongated member, a first one of the framing members, and a second one of the framing members, the pin having a first longitudinal end and a second longitudinal end, at least one of the first longitudinal end and the second longitudinal end of the pin being located in the internal space of the elongated member.
According to a second broad aspect, the invention provides a structural assembly comprising an elongated member defining an internal space. The structural assembly also comprises a plurality of framing members connected to the elongated member at a plurality of nodes. The structural assembly further comprises a support for supporting an illumination system, the illumination system comprising a lighting device for emitting light from the elongated member, at least part of the lighting device being located in the internal space when the support supports the illumination system.
According to a third broad aspect, the invention provides a bridge comprising a first chord defining an internal space. The bridge also comprises a second chord. The bridge further comprises a plurality of web members connected to the first chord at a plurality of pin connection nodes and to the second chord at a plurality of moment-transferring connection nodes. Each pin connection node comprises a pin interconnecting the first chord, a first one of the web members, and a second one of the web members, the pin having a first longitudinal end and a second longitudinal end, at least one of the first longitudinal end and the second longitudinal end of the pin being located in the internal space of the first chord.
According to a fourth broad aspect, the invention provides a bridge comprising a first chord and a second chord and a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. Each node of the first plurality of nodes is a pin connection node, the pin connection node comprising a pin interconnecting the first chord, a first one of the web members, and a second one of the web members, the pin being concealed from view for an observer on the bridge.
According to a fifth broad aspect, the invention provides a bridge comprising a first chord defining an internal space and a second chord. The bridge also comprises a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. The bridge further comprises a support for supporting an illumination system, the illumination system comprising a lighting device for emitting light from the first chord, at least part of the lighting device being located in the internal space when the support supports the illumination system.
According to a sixth broad aspect, the invention provides a bridge comprising a first chord and a second chord. The bridge also comprises a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. Each web member has a central longitudinal axis and comprises a plurality of interior channels, the interior channels receiving a plurality of fasteners each having a longitudinal axis generally parallel to the central longitudinal axis of the web member, the fasteners being adjacent to one another along a direction transverse to the central longitudinal axis of the web member.
According to a seventh broad aspect, the invention provides a structural assembly. The structural assembly comprises an elongated member and a plurality of framing members connected to the elongated member at a plurality of pin connection nodes. Each pin connection node comprises a pin interconnecting the elongated member, a first one of the framing members, and a second one of the framing members, the pin being concealed.
These and other aspects of the invention will now become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying drawings.
A detailed description of embodiments of the invention is provided below, by way of example only, with reference to the accompanying drawings, in which:
It is to be expressly understood that the description and drawings are only for the purpose of illustrating certain embodiments of the invention and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
The structural assembly 12 comprises an assembly of structural members forming a framework of the bridge 10. More particularly, in this embodiment, the structural assembly 12 comprises: a pair of upper elongated members 201, 202, a pair of lower elongated members 221, 222, and a plurality of framing members 241-24N, 301-30N, 321-32M each extending between two of these upper and lower elongated members. The elongated members 201, 202, 221, 222 and the framing members 241-24N, 301-30N, 321-32M are connected to one another at a plurality of nodes, including a plurality of upper nodes 361-36P, 371-37P and a plurality of lower nodes 381-38R, 391-39R.
More particularly, in this embodiment, the bridge 10 is a truss bridge, in this case, a pony-truss bridge (also known as a “half-through” truss bridge), and the structural assembly 12 is a truss assembly in which the upper elongated members 201, 202 are upper chords, the lower elongated members 221, 222 are lower chords, and the framing members 241-24N, 301-30N, 321-32M are web members. The structural assembly 12 can thus be viewed as comprising a first vertical truss 401, which comprises the upper chord 201, the lower chord 221, and the web members 241-24N, and a second vertical truss 402, which comprises the upper chord 202, the lower chord 222, and the web members 301-30N. The framing members 321-32M interconnect the vertical trusses 401, 402 and support a floor (not shown) of the bridge 10 (e.g., stringers, decking, etc.). The bridge 10 may also comprise fencing (not shown) mounted to the vertical trusses 401, 402.
With additional reference to
The upper chord 201 can be made in various ways. In this embodiment, the upper chord 201 is an extruded metallic member. Specifically, in this example, the upper chord 201 is an extruded aluminum member. This may facilitate manufacturing of the upper chord 201 and help to minimize its weight and consequently that of the bridge 10. The upper chord 201 may be made using various other processes and/or other materials in other embodiments. For example, in some embodiments, the upper chord 201 may comprise a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.) and/or may be made of other metallic materials (e.g., steel) or other materials (e.g., polymer, composite).
The upper chord 201 has a periphery 42. In this embodiment, the periphery 42 comprises a top surface 43 and a pair of lateral surfaces 441, 442 opposite one another. In this case, the top surface 43 is generally flat and the lateral surfaces 441, 442 are curved. The periphery 42 may be shaped in various other ways in other embodiments. For example, in other embodiments, the top surface 43 and/or the lateral surfaces 441, 442 may be shaped differently and/or oriented differently, and/or the periphery 42 may comprise one or more other surfaces (e.g., a bottom surface).
The upper chord 201 defines an internal space 48. The internal space 48 is within and delimited by the periphery 42 of the upper chord 201. More particularly, in this embodiment, the upper chord 201 comprises an outer wall 50 defining the periphery 42 and delimiting the internal space 48. Also, in this embodiment, the upper chord 201 comprises a plurality of inner walls 521, 522 which partition the internal space 48 into a plurality of portions, including a first portion 491, a second portion 492 and a third portion 493. In this case, each of the inner walls 521, 522 merges with the outer wall 50 at two points such that each of the first portion 491 and the third portion 493 of the internal space 48 is a closed portion of the internal space 48. In contrast, the second portion 492 of the internal space 48 is open at a bottom of the upper chord 201. In other cases, each of the inner walls 521, 522 may merge with the outer wall 50 at a single point (e.g., near the top surface 43) or at more than two points. The internal space 48 may be configured in various other ways in other embodiments. For example, in some embodiments, the outer wall 50 may be thicker and/or have a varying thickness, and/or the inner walls 521, 522 may have various other shapes and/or thicknesses or may be omitted.
As further discussed below, in this embodiment, the upper nodes 361-36P are located in the internal space 48. The upper chord 201 is configured to facilitate connection of the web members 241-24N to itself at the upper nodes 361-36P, while preventing tampering with these nodes. To that end, in this embodiment, the upper chord 201 comprises a plurality of openings 561-56P, 541, 542, an inner pin-retaining portion 58, and a barrier-supporting portion 71, whose purposes are discussed later on.
The web members 241-24N can be made in various ways. In this embodiment, the web members 241-24N are extruded metallic members. Specifically, in this example, the web members 24-1-24N are extruded aluminum members. This may facilitate manufacturing of the web members 241-24N and help to minimize their weight and consequently that of the bridge 10. The web members 241-24N may be made using various other processes and/or other materials in other embodiments. For example, in some embodiments, each of the web members 241-24N may comprise a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.) and/or may be made of other metallic materials (e.g., steel) or other materials (e.g., polymers, composite).
With additional reference to
Each web member 24i may be configured in various other ways in other embodiments. For example, in other embodiments, the outer wall 70 may have a shape other than circular (e.g., polygonal). As another example, in other embodiments, any one of the inner tubular wall 72 and the inner walls 741-743 may be shaped differently or omitted, or the web member 24i may comprise more or less inner walls such as the inner walls 741-743. As yet another example, in other embodiments, the web member 24i may be full instead of hollow.
Each of the upper nodes 361-36P is a pin connection node, i.e., a node constituting a pin connection. A pin connection is designed to transfer axial and shear forces but not moments. In other words, in two dimensions, a pin connection restrains two translational degrees of freedom but does not restrain a rotational degree of freedom.
Each upper node 36i interconnects a first web member 24j of the web members 241-24N, a second web member 24k of the web members 241-24N, and the upper chord 201. Thus, the web member 24j, the web member 24k, and the upper chord 201 are interconnected via a pin connection.
The upper node 36i comprises a first connecting portion 371 for connecting the web member 24j and a second connecting portion 372 for connecting the web member 24k. In this embodiment, the first connecting portion 371 is part of a first connector 471 which is separate from and mounted to the web member 24j. Similarly, the second connecting portion 372 is part of a second connector 472 separate from and mounted to the web member 24k. In other embodiments, the first connecting portion 371 may be integral with the web member 24j and/or the second connecting portion 372 may be integral with the web member 24k.
The upper node 36i also comprises a pin 60 interconnecting the web member 24j, the web member 24k, and the upper chord 201. The pin 60 comprises an elongated object having a first longitudinal end 621 and a second longitudinal end 622 and suitable for interconnecting the web member 24j, the web member 24k, and the upper chord 201 in a pin connection. For example, in various embodiments, the pin 60 may comprise a rod, a shaft, a key, a fastener (e.g., a bolt or stud with a nut, a screw, etc.), or any other hardware capable of being used to interconnect the web member 24j, the web member 24k, and the upper chord 201 in a manner which permits a degree of rotational movement of one of these structural members relative to another one of these structural members. In this embodiment, the pin 60 comprises a generally cylindrical part. The pin 60 may be configured in various other ways in other embodiments (e.g., the pin 60 may comprise a part having a noncircular periphery).
In this embodiment, the pin 60 also serves to fasten the web member 24j, the web member 24k, and the upper chord 201. To that end, the pin 60 comprises a fastener. For instance, the fastener may be a threaded fastener (e.g., a bolt or stud with a nut, a screw, etc.), a rivet, a clamp, or any device or group of devices capable of fastening the web member 24j, the web member 24k, and the upper chord 201. More specifically, in this embodiment, the pin 60 comprises a bolt.
The connectors 471, 472 may be configured in various ways. In this embodiment, the connectors 471, 472 are made of metal, in this case, aluminum, cast into shape. The connectors 471, 472 may be made of other metallic material (e.g., steel) or other materials (e.g., polymer, composite) and/or using other manufacturing processes (e.g., milled or otherwise machined) in other embodiments. Also, in this embodiment, the connectors 471, 472 are substantially identical, such that only one type of connector needs to be produced for both the web members 24i, 24k. In other embodiments, the connectors 471, 472 may be different from one another.
The connector 471 will be discussed further with an understanding that a similar discussion applies to the connector 472.
In this case, the connector 471 is mounted to an upper extremity of the web member 24j. The connector 471 is dimensioned so as to cover an upper extremity surface 80 of the web member 24i. Here, the connector 471 comprises a circular base portion 82 for abutting the upper extremity surface 80. The connector 471 may be located elsewhere along the length of the web member 24i in other cases.
The connector 471 comprises an upper portion 84 projecting from the base portion 82. In this example, the upper portion 84 is tapered and off-center relative to a central longitudinal axis 21 of the web member 24i. As such, the web members 24i and 24k can be crossed at the location of their connectors 471 and 472 such that their central longitudinal axes 21 intersect. In other embodiments, the central longitudinal axes 21 of the web members 24i and 24k may not intersect.
The upper portion 84 of the connector 471 comprises a contact surface 88 for contacting a corresponding contact surface 88 of the connector 472. In this example, the contact surface 88 is generally flat to facilitate sliding over the corresponding contact surface 88 of the connector 472. In other examples, the contact surface 88 may have a different profile (e.g., curved, jagged, etc.). In yet other examples, there may be no contact surface 88 on the upper portion 84, such as in cases where the connectors 471, 472 do not contact one another at the pin connection node 46i. Indeed, in some embodiments, the connectors 471, 472 may be spaced apart and possibly separated by an intermediate component.
The connector 471 comprises a through-hole 110 to receive the pin 60. When the connector 471 is mounted to the web member 24i, the through-hole 110 extends in a direction transverse to the central longitudinal axis 21 of the web member 24i. In this case, the through-hole 110 extends inwardly from the contact surface 88 such that the contact surface 88 adjacent the through-hole 110 acts as a bearing surface.
The connector 471 may be mounted to the web member 24i in various ways. In this embodiment, the connector 471 is mounted to the web member 24i via a fastener 86. In this example, the fastener 86 is a threaded fastener, and more specifically a bolt. An aperture 90 provides a passage through the circular base 82 for receiving the fastener 86. The fastener 86 holds the connector 471 to the web member 24i by engaging the inner tubular wall 72 defining the inner elongated channel 76 to screw tightly therein. For instance, the inner elongated channel 76 may comprise internal threading to engage threads of the fastener 86. A recess 92 is provided in the upper portion 84 to accommodate, and provide access to, a head of the bolt.
In this embodiment, the fastener 86 extends along a neutral axis of the web member 24i, which in this case corresponds to the central longitudinal axis 21. In embodiments, the fastener 86 may extend along a different longitudinal axis of the web member 24i. For example, in some embodiments, the fastener 86 may extend along an axis parallel to the neutral axis of the web member 24i. The fastener 86 may be oriented or otherwise arranged in various other ways to fasten the connector 471 to the web member 24i in other embodiments.
When assembled, the upper node 36i interconnects the web member 24j, the web member 24k, and the upper chord 201. Specifically, the opening 56i in the outer wall 50 of the upper chord 201 and the openings 541, 542 in the inner walls 521, 522 of the upper chord are coaxial such that the pin 60 can be inserted through the opening 56i and extend through the openings 541, 542 and the through-holes 110 of the connectors 471, 472 mounted to the web members 24i, 24k. This allows a degree of rotation of the upper chord 201, the web member 24i and the web member 24k relative to one another about the longitudinal axis of the pin 60.
Also, in this embodiment, the pin 60 is held in place and fastens together the web member 24j, the web member 24k, and the upper chord 201. Specifically, in this embodiment, the pin 60 comprises a bolt which comprises a tool-engaging head 64 and a shank 65 with threads. The bolt is held in place and fastens together the web member 24j, the web member 24k, and the upper chord 201 by having the tool-engaging head 64 abut against the inner wall 511 of the upper chord 201 and the threads of the shank 65 engaged in the inner pin-retaining portion 58 of the upper chord 201.
More particularly, in this example, the inner pin-retaining portion 58 is a thread-engaging portion which comprises a pair of ridged surfaces 591, 592 having facing each other for engaging the threads on the bolt 60. Thus, the bolt 60 can be screwed into place in the upper chord 201. In this case, the ridged walls 591 and 592 are straight and run the entire length of the upper chord 201 so that they can be formed during the upper chord's extrusion process. The inner pin-retaining portion 58 may be configured in various other ways in other embodiments. For instance, in some embodiments, the inner pin-retaining portion 58 may comprise a built-in nut-like structure.
In this embodiment, the upper node 36i is concealed from view and inaccessible to an observer on the bridge 10. This may improve overall esthetics of the bridge 10 and discourage potential vandals from attempting to tamper with the upper node 36i.
More particularly, in this embodiment, the first longitudinal end 621 and the second longitudinal end 622 of the pin 60 are located in the internal space 48 of the upper chord 201. This positioning of the first and second longitudinal ends 621 and 622 of the pin 60 in the internal space 48 creates a natural concealment of the pin 60. In other embodiments, only one of the longitudinal ends 621, 622 of the pin 60 may be located in the internal space 48, while the other one may be located outside of the internal space 48.
The first longitudinal end 621 and the second longitudinal end 622 of the pin 60 are thus located within the periphery 42 of the upper chord 201. That is, each of the longitudinal ends 621, 622 of the pin 60 does not extend beyond the periphery 42 of the upper chord 201. Specifically, in this embodiment, each of the longitudinal ends 621, 623 of the pin 60 is located between the lateral surfaces 441, 442 of the upper chord 201.
The opening 56i in the outer wall 50 of the upper chord 201 and the openings 541, 542 in the inner walls 521, 522 of the upper chord 201 allow the pin 60 to be inserted from a single side of the upper chord 201, such that no opening is required in the outer wall 50 on the opposite side of the opening 56i. Thus, in this embodiment, the outer wall 50 is free of (i.e., lacks) openings extending inwardly from the lateral surface 442 and aligned with the openings 561-56P. As such, when the pin 60 is inserted, the second longitudinal end 622 of the pin 60 is within the internal space 48 (in this case, within the third portion 493 of the internal space 48) and concealed from view to an observer on the bridge 10. Because there is no need to have openings extending inwardly from the lateral surface 442 of the upper chord 201, in this embodiment, the lateral surface 442, which faces the pathway of the bridge 10 and is thus viewed by observers on the bridge 10, is a flush continuous surface.
The pin 60 is inserted deep enough into the upper chord 201 that its first longitudinal end 621 is in the internal space 48 of the upper chord 201. In this case, the first longitudinal end 621 of the pin is in the first portion 491 of the internal space 48 of the upper chord 201. Although the first longitudinal end 621 of the pin 60 is located in the internal space 48 of the upper chord 201, a plug (not shown) may be inserted into the opening 56i so as to block the opening 56i and conceal the first longitudinal end 621 of the pin 60 from an observer. Such plugs in the openings 561-56p may also improve the overall esthetics of the bridge 10 when viewed from the side of the openings 561-56p.
While plugs can be useful, they can sometimes be removed with a tool such as a screw driver. Therefore, while plugging the opening 56i with a plug may block the view of the pin 60, it may not necessarily greatly reduce the possibility of tampering with the pin 60. In particular, in some cases, it may be desirable to render the pin 60 inaccessible, for example, to preclude vandals from tampering with the pin 60.
To that end, in this embodiment, a tamperproof arrangement 100 is provided to prevent access to the pin 60. More particularly, in this embodiment, the tamperproof arrangement 100 comprise a barrier 104 supported by the aforementioned barrier-supporting portion 71 of the upper chord 201. The barrier 104 is placed in front of the first longitudinal end 621 of the pin 60 and blocks access to the pin 60 through the opening 56i.
In this example, the barrier-supporting portion 71 comprises upper and lower projections 1061, 1062 that run the entire length of the upper chord 201 such that the barrier-supporting portion 71 can be formed during the chord's extrusion process. The barrier 104 comprises a blocking panel which can be slidably received in the barrier-supporting portion 71 from a longitudinal extremity of the upper chord 201. In this case, this blocking panel extends the entire length of the upper chord 201. In other cases, the barrier 104 may be discontinuous and present only in the vicinity of the openings 561-56p. Although the brace 102 is shown here as extending inwards from the outer wall 50, it should be understood that the brace 102 may be formed in one or more other walls. For example the brace 102 may consist of projections extending from the inner wall 521.
The tamperproof arrangement 100 may be configured in various other ways in other embodiments. For example, in other embodiments, the barrier-engaging portion 71 may be shaped differently and/or may be formed in one or more other walls of the upper chord 201 (e.g., the inner wall 521). Also, in other embodiments, the barrier 104 may comprise any other suitable component for preventing access to the pin 60. For example, the barrier 104 may comprise one or more tamper-proof plugs that may be used instead of regular plugs to block opening 561-56p. Such tamper-proof plugs may snap-in permanently, be glued, or be affixed by non-removable fasteners.
Also, while in this embodiment the tamperproof arrangement 100 is provided only on the side of the upper chord 201 which has the opening 56i since only the opening 56i allows access to the pin 60 (as the second longitudinal end 622 of the pin 60 is inaccessible by virtue of being located in the interior space 48 and overlaid by the lateral surface 442 of the outer wall 50), in other embodiments, the tamperproof arrangement 100 may comprise one or more other components anywhere where access is to be blocked. For example, in embodiments where an opening is provided in the upper chord 201 on the opposite side of the opening 561 (giving access to the second longitudinal end 622 of the pin 60), the tamperproof arrangement 100 may comprise a barrier and barrier-supporting portion, similar to the barrier 104 and the barrier-supporting portion 71, on that opposite side of the upper chord 201 as well.
The web members 24i, 24k protrude from a bottom region of the upper chord 201. As such, in this embodiment, the internal space 48 is open at the bottom region of the upper chord 201 to allow passage of the web members 24j, 24k. However, in this embodiment, in areas of the upper chord 201 between the upper nodes 361-36p, the bottom region of the upper chord 201 is closed.
More particularly, in this embodiment, a barrier 114 is mounted to the upper chord 201 to close the bottom region of the upper chord 201 in the areas between the upper nodes 361-36p. The barrier 114 may comprise any suitable structure openable (e.g., hinged), removable or permanently affixed to the upper chord 201 to close its bottom region in the areas between the upper nodes 361-36p. In this example, the barrier 114 comprises a door hingedly connected to the upper chord 201 (in this case, to the inner wall 521 of the upper chord 201) so that it can be “swung” open. In this case, the door is hingedly connected via a live hinge 121. In other cases, the door may be hinged by any other hinging means (e.g., a pivot hinge). In this example, the door also comprises a retaining portion 118 to keep it in its closed position. In this case, the retaining portion 118 is a snap-fit portion which fits in a corresponding recess formed by the outer wall 50 of the upper chord 201. In other embodiments, the barrier 114 may be removable (e.g. by having snap-fit arrangements on both transverse sides or by any other means) or may be permanently affixed to the bottom region of the upper chord 201 (e.g. by being permanently snap-fit into place, by being glued, or by being welded in place). The barrier 114 may also be slid into place from a longitudinal end of the upper chord 201 during assembly.
In this embodiment, the structural assembly 12 comprises a support 89 for supporting an illumination system 112 for emitting light from the upper chord 201. The illumination system 112 comprises one or more lighting devices to emit light, which can be used on the bridge 10 for functional and/or aesthetic reasons. In this embodiment, the support 89 is implemented by the barrier 14 in the bottom region of the upper chord 201. The support 89 may be implemented in various other ways in other embodiments (e.g., by the outer wall 50, one or more of the inner walls 521, 522, and/or another portion of the upper chord 201).
More particularly, in this embodiment, the illumination system 112 comprises a plurality of lighting devices 1201-120L distributed along the upper chord 201. At least part of each of the lighting devices 1201-120L is located in the internal space 48 of the upper chord 201. This helps to protect the lighting devices 1201-120L. In this example, the lighting devices 1201-120L are mounted to the barrier 114 in the bottom region of the upper chord 201 for illuminating an area beneath the upper chord 201. In other examples, the lighting devices 1201-120L may be mounted elsewhere on the upper chord 201 for illuminating one or more other areas adjacent to (e.g., adjacent, on lateral sides, etc.) the upper chord 201.
Each of the lighting devices 1201-120L may take on various forms. In this embodiment, the lighting devices 1201-120L are light-emitting diode (LED) lighting devices. More specifically, in this case, each of the LED lighting devices 1201-120L comprise three different LED light sources, each generating light of a different color. In other cases, each of the LED lighting devices 1201-120L may emit monochromatic light only. The lighting devices 1201-120L may take on other forms (e.g., light bulbs) in other embodiments.
Illumination may be controlled by any suitable means (e.g., for turning the lights on and off, and/or for providing light of different colors). In this example, wires (not shown) connected to the lighting devices 1201-120L for powering and/or controlling the lighting devices 1201-120L run inside the internal space 48 of the upper chord 201. This protects the wires and connections to the lighting devices 1201-120L from weather elements and avoids the esthetical unpleasantness of exposed wires.
As described above, in this embodiment, the upper chord 201 has the barrier 104 inserted therein from a longitudinal end of the upper chord 201 as well as the barrier 114 slid into place from a longitudinal end of the upper chord 201. In order to increase the tamper-proofness of the bridge 10, in this embodiment, each of the longitudinal ends of the upper chord 201 is fitted with an end-piece 195, as shown in
Turning now to the lower chord 221, in this embodiment, the web members 241-24N and the lower chord 221 connect together at the lower nodes 381-38R by way of respective lower node connectors 1301-130R. The framing members 321-32M are connected to the lower chord 221 via the lower node connectors 1301-130R. In this case, the framing members 321-32m include transverse members 1341-134s and floor diagonals 1321-132Q.
Connections to the lower chord 221 will now be described with reference to
In this embodiment, the lower node 38i is a moment-transferring connection node, i.e., a node constituting a moment-transferring connection, which is a connection designed to transfer axial and shear forces as wells moments. In other words, in two dimensions, a moment-transferring connection restrains two translational degrees of freedom and a rotational degree of freedom.
More particularly, the lower node connector 130i is able to transfer bending moments. In this example, the transverse member 134j comprises a first longitudinal end 138 that is inserted into a cavity 1421 of the lower node connector 130i. The web members 24k, 24m comprise respective lower longitudinal ends 140k, 140m that are inserted into respective cavities 1422, 1423 of the lower node connector 130i. The web members 24k, 24m and the transverse member 134j may have tapered end portions for inserting into the respective cavities 1422, 1423, 1421. The tapered end portions of the web members 24k, 24m and the transverse member 134j may be machined (e.g., milled, turned, swaged) or brought to this tapered shape by any other process.
The lower node connector 130i is connected to the lower chord 221. In this embodiment, the lower node connector 130i comprises a channel 144 for receiving the lower chord 221. In this case, the channel 144 is open to allow the lower node connector 130i to simply be placed over the lower chord 221 to embrace the lower chord 221 in the channel 144. In other cases, the channel 144 may be closed (that is, surrounded as in a tunnel or partially surrounded such that the lower chord 221 cannot escape the channel 144 except by sliding out of it), requiring the lower node connector 130i to be slid into place along the lower chord 221.
Any suitable fastener may be used for securing the lower node connector 130i and the lower chord 221 to one another. In this embodiment, a pair of threaded fasteners is used to this end. More specifically, the lower node connector 130i is fastened to the lower chord 22i by a pair of bolts 148 and nuts 149 through two like pairs of holes adapted to align the lower node connector 130i and the lower chord 221. Both of the floor diagonals 132i, 132j attach to the lower node connector 130i with bolts 158 and nuts 159.
The web members 140k, 140m and the transverse member 134j may be secured to the lower node connector 130i in various manners. In this embodiment, the lower node connector 130i is adapted to receive a fastener 152 for holding each of the web members 24k, 24m and the transverse member 134j in place in their respective cavities 1422, 1423, 1421. The lower node connector 130i comprises an aperture 150 through the bottom of each cavity 1422, 1423, 1421 such that, for each cavity, the fastener 152 can extend between the channel 144 and the cavity. In this example, the fasteners 152 are bolts that screw into the interior elongated channel 76 of the web members 24k, 24m in a manner similar to that described above in relation to the fastener 86.
In this case, the fasteners 152 each have a tool-engaging head 153 and recesses 151 are provided to accommodate the tool engaging heads 153 of fasteners 152. The recesses 151 may be dimensioned so as to allow a tool to engage a tool-engaging head 153 while within the recess 151. In such a way, before the lower chord 221 is inserted into the channel 144, the fasteners 152 can be inserted into apertures 150 through the channel 144 into the respective web members 24k, 24m or transverse member 134j until the tool-engaging heads 153 are contained within respective recesses 151. In this way, the channel 144 is not blocked by the fasteners and the lower chord 221 is not impeded from being received therein. In addition to allowing unimpeded close contact between the lower chord 221 and the lower node connector 1301, this arrangement has the added benefit that once the lower chord 221 is installed, the fasteners 152, and particularly their tool engaging heads 153, are not only concealed from sight of observers on or around the bridge 10, but they are rendered inaccessible such that an observer cannot remove the fasteners 152 so long as the lower chord 221 is in place in the channel 144. Indeed, so long as the lower chord 221 is in the channel 144, the fasteners 152, and particularly their tool engaging heads 153 cannot be reached with a tool or otherwise, and the fasteners are prevented from backing out of their respective apertures 150 by the lower chord 221.
The lower node connector 130i thus forms a very stable connection between the lower chord 221, the transverse member 130j and the web members 24k, 24m for maintaining structural integrity throughout the lower chord 221. As shown in reference to
The floor diagonals 132i, 132j act to resist horizontal loading act on the projected area of the bridge 10. The web members 24k, 24m act to resist tension and compression forces but they also transfer some bending moment to the transverse member 134j as well as they transfer torsion to the lower chord 221
The web members 140k, 140m and the transverse member 134j may be secured to the lower node connector 130i in various other ways in other embodiments. For example,
In view of the foregoing, in this embodiment, the structural assembly 12 of the bridge 10 may be a “weldless” structural assembly, i.e., it can be assembled with no welding being required to hold together its structural members. This may greatly simplify the distribution and assembly process of the bridge 10, making it suitable for uses and in locations otherwise not suited for welded bridges. Furthermore, individual components may be shipped individually for assembly, and this assembly may be performed without expensive welding services. Furthermore, the structural assembly 12 may be disassemblable, making it possible to easily relocate it or to simply take it down, opening up the prospect of installing it in non-permanent locations or even renting it.
While in this embodiment the structural assembly 12 is configured in a particular way, the structural assembly 12 may be configured in various other ways in other embodiments.
For example, in some embodiments, the structural assembly 12 may comprise other structural members and components to make the bridge 10 longer. For instance, as shown in
As another example, although in this embodiment the upper chord 201 is a one-piece member, in other embodiments, the upper chord 201 may be a multi-piece member comprising a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.). For instance, as shown in
As another example, in other embodiments, a web member 24x of the web members 241-24N may be connected to a connector 47x of the connectors 471, 472 of an upper node 36x of the upper nodes 361-36P by two or more fasteners such as the fastener 86. For instance, as shown in
As another example, although in this embodiment the lighting devices 1201-120L are present on the underside of the upper chord 201, in other embodiments, the lighting devices 1201-120L of the illumination system 112 may be placed elsewhere on the bridge 10 to illuminate in any desired direction. For instance, some or all of the lighting devices 1201-120L may be arranged along the lower chord 221 in a manner similar to that described above in respect of the upper chord 201.
As another example, in some embodiments, the structural assembly 12 may support a sound system comprising one or more speakers, which may be arranged in a manner similar to the lighting devices 1201-120L of the illumination system 112 discussed above, with wires running inside the internal space 48 of the upper chord 201 or mounted to other components (e.g., the lower chord 221).
Although in this embodiment the bridge 10 is a pedestrian bridge, in other embodiments, the bridge 10 may be another type of bridge. For example, in some embodiments, the bridge 10 may be a bridge providing a pathway for vehicles (e.g., automobiles, trucks, military vehicles, etc.).
While in this embodiment the structural assembly 12 is included in a bridge, the structural assembly 12 may be part of structures other than bridges in other embodiments. For example, in other embodiments, structural assemblies such as the structural assembly 12 may part of, inter alia, buildings, fences, towers (e.g., antennae tower), gantries (e.g., motorway gantries, crane gantries, etc.), flag post bases, furniture, and various other lattice structures and other types of structures.
Although various embodiments and examples have been presented, this was for the purpose of describing, but not limiting, the invention. Various modifications and enhancements will become apparent to those of ordinary skill in the art and are within the scope of the invention, which is defined by the appended claims.
This application claims priority from U.S. Provisional Patent Application No. 61/103,181 filed on Oct. 6, 2008 and hereby incorporated by reference herein.
Number | Date | Country | |
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61103181 | Oct 2008 | US |
Number | Date | Country | |
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Parent | 13122955 | Apr 2011 | US |
Child | 14204735 | US |