Patent Application
20190024393
The following relates generally to modular scaffolding systems, and more particularly to scaffolding systems comprising modular truss sections.
Scaffolding refers to a temporary structure used to support a work crew and some building materials during a construction project.
Scaffolding structures generally comprise several vertical posts (commonly referred to as “standards”) spaced apart longitudinally by truss sections, and spaced apart laterally by other members (commonly referred to as “bearers”). Each of the truss sections and bearers are joined to the vertical posts by clamps or other fixing mechanisms. Scaffolding structures are often topped with a series of beams which may be covered by a deck (often made of plywood planks) for permitting movement thereupon by members of the work crew or placement of equipment.
Scaffolding is most commonly assembled from a series of pre-constructed parts having desired dimensions for the particular use. Truss sections of scaffolding systems, particularly when used as part of the span of a structure providing a temporary bridge or suspended walkway, are commonly sized to be about 14′ long, though may also be fabricated to various other lengths, for example 17′, 21′ or 28′.
Manipulation of such truss sections is burdensome. The truss sections are long, heavy, and hard to work with. Transportation of the sections is also costly. Moreover, on a construction site, because the longer sections cannot fit into elevators, they often have to be hoisted upward as a construction project ascends its successive stages.
Modular scaffolding systems are known. Most include geometrically complex, easily broken attachment pieces for connecting parts in order to achieve modularity. Often such attachment pieces comprise brackets for encircling the ends of horizontal members of, for example, the truss sections.
A simpler, versatile, easy to use modular scaffolding system is needed.
A greater understanding of the embodiments will be had with reference to the Figures, in which:
For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the Figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practised without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.
Various terms used throughout the present description may be read and understood as follows, unless the context indicates otherwise: “or” as used throughout is inclusive, as though written “and/or”; singular articles and pronouns as used throughout include their plural forms, and vice versa; similarly, gendered pronouns include their counterpart pronouns so that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc. by a single gender; “exemplary” should be understood as “illustrative” or “exemplifying” and not necessarily as “preferred” over other embodiments. Further definitions for terms may be set out herein; these may apply to prior and subsequent instances of those terms, as will be understood from a reading of the present description.
As set out above, an improved modular scaffolding system is needed, particularly to enable easy manipulation of truss sections to various lengths for use in scaffolding bridges and suspended walkways.
Various embodiments are described herein relating to scaffolding systems where truss sections can be assembled together with connectors to achieve length modularity. To assemble the truss sections, a pair of connectors are positioned within openings defined in the horizontal runners of each truss section, such that the connectors extend between successive assembled sections, and the connectors are each further fixed to the sections with one or more fasteners. Additionally, each truss section has a vertical member extending between the horizontal runners proximal the connectors in order to enable acceptable vertical loading characteristics.
With the scaffolding systems described herein, manipulation, assembly and disassembly of various lengths of truss sections is facilitated. Erection of scaffolding systems having different lengths to fit the needs of different construction jobs is thereby streamlined. Surprisingly, the systems have been found to have similar strength to resist vertical loading in some configurations as if the assembled truss sections were integrally formed.
Various embodiments of the modular scaffolding system will now be described with reference to the drawings.
Referring to
The first truss section 102 comprises at least two vertical members 116, at least two horizontal runner members 110 (referred to as “runners”) spaced apart by the vertical members and one or more diagonal braces 112 (providing the ‘truss’ construction). The diagonal braces may be disposed at various angles with respect to the runners, for example 55 degrees. At a first end 109 of the first truss section, it is attached by a known attachment mechanism 106 to a vertical post 108 (a “standard”), for example of a scaffolding tower. The attachment mechanism may comprise a clamp, though other attachment mechanisms are known to those of skill in the art. At a second end 111, each horizontal runner is shaped to define an elongate opening 124 for receiving a portion of an elongate connector pin 118 (best shown in
The second truss section 104 has fundamentally the same construction as the first truss section, though the disposition of its defined openings and the attachment mechanism connecting it to the illustrated vertical post are each shown to be horizontally flipped compared to the first truss section, and the second truss section is shown to be shorter longitudinally than the first truss section. It will be appreciated from the following that each truss section may be connected to a vertical post at one end and define openings for receiving a connector pin at the other, or may define openings at both ends (and thus have two connection ends), depending on the positioning of the truss section in the respective scaffolding system. For example, a truss section positioned between two other truss sections will define openings for receiving connectors at each end.
It should be appreciated that the scaffolding system 100 forms one panel of a scaffold structure. To form a complete scaffold structure by making use of the scaffolding system 100, the vertical posts 108 may be joined with additional truss sections, tangential members (“bearers”), and ultimately indirectly connected to several other vertical posts. Further, once assembled, beams and a deck may be added atop the scaffold to permit movement of work men above. Referring to
To assemble the first truss section 102 and the second truss section 104 in order to achieve modularity, a connector 118 is positioned within, and extends between, the elongated openings 124 of each runner of the truss sections (best shown in
To enable fastening of the connectors to the truss sections, in a particular embodiment illustrated in
In other embodiments comprising similar fasteners, more or less apertures may be defined. For example, the connector may define two apertures, and a single aperture may in that instance be defined at the connection end of each runner. However, assuming each respective fastener is of the same strength, generally having more than one fastener is advantageous as it distributes shear stress between more than a single fastener, reducing the risk if a fastener shears, and eliminating the existence of a single point of failure.
In order to bear any vertical downward force upon the truss sections (i.e. along the direction of the vertical member, at least one vertical member 116 is disposed proximal the connection end of each truss section, extending between the runners. Though the vertical members 116 and 116′ are shown to be spaced a short distance from the connection ends of the runners, it may be optimal for the vertical member to be positioned substantially adjacent the connection end of the runners to improve loading characteristics.
In embodiments where two apertures are provided at the connection end of each runner for receiving fasteners, preferably the apertures are spaced about the proximal vertical member (see member 116′ illustrated in
Referring now to the construction of the truss sections, the members are all preferably made of steel, aluminum or a composite scaffolding material (which may include glass or nylon fiber). The connector is preferably made of a solid piece of material, preferably a metal, such as steel or a material having similar strength characteristics for the relevant type of loading. As is common in the scaffolding industry, the runner members and vertical members may have a tubular construction, though other shapes are possible. The elongate openings may thus comprise part of the tubular shape rather than a separate defined geometry. This eliminates the need to adapt the connection end of the runners to form a particular shape of opening, rather than utilizing the pre-existing tubular shape in common use today. However other shapes of the elongate openings and connector are contemplated. Particularly, the elongate opening may have a square or rectangular profile. In the rectangular case, the vertical direction may define the length of the rectangular profile. In each case, the connector preferably has a complementary shape profile to the openings, and the openings must extend long enough into the runners to receive the connector (by neighbouring truss sections) when assembled.
Optionally, a support 126 may be added to the scaffolding system if loads are expected to be high. Once two truss sections are assembled, the support 126 may be positioned below the truss sections to extend therebetween, and be attached thereto for extra support (as best shown in
Referring to
Referring to
Possible dimensions of the various elements will now be described with particular reference to
Referring now to
Referring to
Loads were then successively added, as shown at P1, P2, P3, P4 until failure. The maximum load applied to the configuration was 35,271.6 lb (156.9 kN) representing 82.15 lb per square foot (3.93 kN/m2) loading or 157.46 pounds per linear foot (2.3 kN/m) of truss with a Factor of Safety of 4:1. The towers 704 and 714 were 3′10″ (1.17 m) square towers erected at each end of the setup, with the 28 foot modular trusses mounted between the towers. Each of the towers 704, 714 was loaded with ballast to ensure that unwanted deflection would not occur due to deformation of the towers. Ledgers and screwjacks were set on the floor between the towers to correctly position the towers. Ledgers (i.e. cross-brace 702) were attached to the bottom chords of the trusses to provide lateral bracing to ensure that the trusses would not twist under load.
Loading was carried out by setting racks of equipment onto a plywood platform supported by aluminum beams mounted across the trusses. Deflection (Δ) at the center of the trusses was noted as each rack was placed onto the platform. The load was gradually increased until failure. It is noteworthy that the tested configuration was found to only be about 10% weaker to vertical uniform distributed load (“UDL”) than a comparable construction including truss sections integrally joined.
Referring to
Table 1 shows results of a first load test.
Table 2 shows results of a second test after checking that standards (i.e. vertical posts) were vertical, and installing ledgers (i.e. cross-bracing) on three sides, ensuring that the now four ledgers are leveled in place, and leaving the front open for loading.
Table 3 shows a review of the loading results with the test configuration.
Referring to
Although the foregoing has been described with reference to certain specific embodiments, various modifications thereto will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| 62535536 | Jul 2017 | US |
